platform/kernel/linux-starfive.git
4 years agopowerpc/numa: Set numa_node for all possible cpus
Srikar Dronamraju [Tue, 18 Aug 2020 08:11:02 +0000 (13:41 +0530)]
powerpc/numa: Set numa_node for all possible cpus

A Powerpc system with multiple possible nodes and with CONFIG_NUMA
enabled always used to have a node 0, even if node 0 does not any cpus
or memory attached to it. As per PAPR, node affinity of a cpu is only
available once its present / online. For all cpus that are possible but
not present, cpu_to_node() would point to node 0.

To ensure a cpuless, memoryless dummy node is not online, powerpc need
to make sure all possible but not present cpu_to_node are set to a
proper node.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200818081104.57888-2-srikar@linux.vnet.ibm.com
4 years agopowerpc/numa: Restrict possible nodes based on platform
Srikar Dronamraju [Mon, 17 Aug 2020 05:52:57 +0000 (11:22 +0530)]
powerpc/numa: Restrict possible nodes based on platform

As per draft LoPAPR (Revision 2.9_pre7), section B.5.3 "Run Time
Abstraction Services (RTAS) Node" available at:
  https://openpowerfoundation.org/wp-content/uploads/2020/07/LoPAR-20200611.pdf

... there are 2 device tree properties:

  "ibm,max-associativity-domains"
   which defines the maximum number of domains that the firmware i.e
   PowerVM can support.

and:

  "ibm,current-associativity-domains"
   which defines the maximum number of domains that the current
   platform can support.

The value of "ibm,max-associativity-domains" is always greater than or
equal to "ibm,current-associativity-domains" property. If the latter
property is not available, use "ibm,max-associativity-domain" as a
fallback. In this yet to be released LoPAPR, "ibm,current-associativity-domains"
is mentioned in page 833 / B.5.3 which is covered under under
"Appendix B. System Binding" section

Currently powerpc uses the "ibm,max-associativity-domains" property
while setting the possible number of nodes. This is currently set at
32. However the possible number of nodes for a platform may be
significantly less. Hence set the possible number of nodes based on
"ibm,current-associativity-domains" property.

Nathan Lynch had raised a valid concern that post LPM (Live Partition
Migration), a user could DLPAR add processors and memory after LPM
with "new" associativity properties:
  https://lore.kernel.org/linuxppc-dev/871rljfet9.fsf@linux.ibm.com/t/#u

He also pointed out that "ibm,max-associativity-domains" has the same
contents on all currently available PowerVM systems, unlike
"ibm,current-associativity-domains" and hence may be better able to
handle the new NUMA associativity properties.

However with the recent commit dbce45628085 ("powerpc/numa: Limit
possible nodes to within num_possible_nodes"), all new NUMA
associativity properties are capped to initially set nr_node_ids.
Hence this commit should be safe with any new DLPAR add post LPM.

  $ lsprop /proc/device-tree/rtas/ibm,*associ*-domains
  /proc/device-tree/rtas/ibm,current-associativity-domains
    00000005 00000001 00000002 00000002 00000002 00000010
  /proc/device-tree/rtas/ibm,max-associativity-domains
    00000005 00000001 00000008 00000020 00000020 00000100

  $ cat /sys/devices/system/node/possible ##Before patch
  0-31

  $ cat /sys/devices/system/node/possible ##After patch
  0-1

Note the maximum nodes this platform can support is only 2 but the
possible nodes is set to 32.

This is important because lot of kernel and user space code allocate
structures for all possible nodes leading to a lot of memory that is
allocated but not used.

I ran a simple experiment to create and destroy 100 memory cgroups on
boot on a 8 node machine (Power8 Alpine).

Before patch:
  free -k at boot
                total        used        free      shared  buff/cache   available
  Mem:      523498176     4106816   518820608       22272      570752   516606720
  Swap:       4194240           0     4194240

  free -k after creating 100 memory cgroups
                total        used        free      shared  buff/cache   available
  Mem:      523498176     4628416   518246464       22336      623296   516058688
  Swap:       4194240           0     4194240

  free -k after destroying 100 memory cgroups
                total        used        free      shared  buff/cache   available
  Mem:      523498176     4697408   518173760       22400      627008   515987904
  Swap:       4194240           0     4194240

After patch:
  free -k at boot
                total        used        free      shared  buff/cache   available
  Mem:      523498176     3969472   518933888       22272      594816   516731776
  Swap:       4194240           0     4194240

  free -k after creating 100 memory cgroups
                total        used        free      shared  buff/cache   available
  Mem:      523498176     4181888   518676096       22208      640192   516496448
  Swap:       4194240           0     4194240

  free -k after destroying 100 memory cgroups
                total        used        free      shared  buff/cache   available
  Mem:      523498176     4232320   518619904       22272      645952   516443264
  Swap:       4194240           0     4194240

Observations:
  Fixed kernel takes 137344 kb (4106816-3969472) less to boot.
  Fixed kernel takes 309184 kb (4628416-4181888-137344) less to create 100 memcgs.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
[mpe: Reformat change log a bit for readability]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200817055257.110873-1-srikar@linux.vnet.ibm.com
4 years agopowerpc/topology: Override cpu_smt_mask
Srikar Dronamraju [Fri, 7 Aug 2020 07:45:17 +0000 (13:15 +0530)]
powerpc/topology: Override cpu_smt_mask

On Power9, a pair of SMT4 cores can be presented by the firmware as a SMT8
core for backward compatibility reasons, with the fusion of two SMT4 cores.
Powerpc allows LPARs to be live migrated from Power8 to Power9.  Existing
software developed/configured for Power8, expects to see a SMT8 core.

In order to maintain userspace backward compatibility (with Power8 chips in
case of Power9) in enterprise Linux systems, the topology_sibling_cpumask
has to be set to SMT8 core.

cpu_smt_mask() should generally point to the cpu mask of the SMT4 core.
Hence override the default cpu_smt_mask() to be powerpc specific
allowing for better scheduling behaviour on Power.

schbench
(latency measured in usecs, so lesser is better)
Without patch                   With patch
Latency percentiles (usec) Latency percentiles (usec)
50.0000th: 34            50.0000th: 38
75.0000th: 47            75.0000th: 52
90.0000th: 54            90.0000th: 60
95.0000th: 57            95.0000th: 64
*99.0000th: 62           *99.0000th: 72
99.5000th: 65            99.5000th: 75
99.9000th: 76            99.9000th: 3452
min=0, max=9205          min=0, max=9344

schbench (With Cede disabled)
Without patch                   With patch
Latency percentiles (usec)  Latency percentiles (usec)
50.0000th: 20            50.0000th: 21
75.0000th: 28            75.0000th: 29
90.0000th: 33            90.0000th: 34
95.0000th: 35            95.0000th: 37
*99.0000th: 40           *99.0000th: 40
99.5000th: 48            99.5000th: 42
99.9000th: 94            99.9000th: 79
min=0, max=791           min=0, max=791

perf bench sched pipe
usec/ops : lesser is better
Without patch
  N           Min           Max        Median           Avg        Stddev
101      5.095113      5.595269      5.204842     5.2298776    0.10762713

5.10 - 5.15 : ##################################################   23% (24)
5.15 - 5.20 : #############################################        21% (22)
5.20 - 5.25 : ##################################################   23% (24)
5.25 - 5.30 : #########################                            11% (12)
5.30 - 5.35 : ##########                                            4% (5)
5.35 - 5.40 : ########                                              3% (4)
5.40 - 5.45 : ########                                              3% (4)
5.45 - 5.50 : ####                                                  1% (2)
5.50 - 5.55 : ##                                                    0% (1)
5.55 - 5.60 : ####                                                  1% (2)

With patch
  N           Min           Max        Median           Avg        Stddev
101      5.134675      8.524719      5.207658     5.2780985    0.34911969

5.1 - 5.5 : ##################################################   94% (95)
5.5 - 5.8 : ##                                                    3% (4)
5.8 - 6.2 :                                                       0% (1)
6.2 - 6.5 :
6.5 - 6.8 :
6.8 - 7.2 :
7.2 - 7.5 :
7.5 - 7.8 :
7.8 - 8.2 :
8.2 - 8.5 :

perf bench sched pipe (cede disabled)
usec/ops : lesser is better
Without patch
  N           Min           Max        Median           Avg        Stddev
101      7.884227     12.576538      7.956474     8.0170722    0.46159054

7.9 - 8.4 : ##################################################   99% (100)
8.4 - 8.8 :
8.8 - 9.3 :
9.3 - 9.8 :
9.8 - 10.2 :
10.2 - 10.7 :
10.7 - 11.2 :
11.2 - 11.6 :
11.6 - 12.1 :
12.1 - 12.6 :

With patch
  N           Min           Max        Median           Avg        Stddev
101      7.956021      8.217284      8.015615     8.0283866   0.049844967

7.96 - 7.98 : ######################                               12% (13)
7.98 - 8.01 : ##################################################   28% (29)
8.01 - 8.03 : ####################################                 20% (21)
8.03 - 8.06 : #########################                            14% (15)
8.06 - 8.09 : ######################                               12% (13)
8.09 - 8.11 : ######                                                3% (4)
8.11 - 8.14 : ###                                                   1% (2)
8.14 - 8.17 : ###                                                   1% (2)
8.17 - 8.19 :
8.19 - 8.22 : #                                                     0% (1)

Observations: With the patch, the initial run/iteration takes a slight
longer time. This can be attributed to the fact that now we pick a CPU
from a idle core which could be sleep mode. Once we remove the cede,
state the numbers improve in favour of the patch.

ebizzy:
transactions per second (higher is better)
without patch
  N           Min           Max        Median           Avg        Stddev
100       1018433       1304470       1193208     1182315.7     60018.733

1018433 - 1047037 : ######                                                3% (3)
1047037 - 1075640 : ########                                              4% (4)
1075640 - 1104244 : ########                                              4% (4)
1104244 - 1132848 : ###############                                       7% (7)
1132848 - 1161452 : ####################################                 17% (17)
1161452 - 1190055 : ##########################                           12% (12)
1190055 - 1218659 : #############################################        21% (21)
1218659 - 1247263 : ##################################################   23% (23)
1247263 - 1275866 : ########                                              4% (4)
1275866 - 1304470 : ########                                              4% (4)

with patch
  N           Min           Max        Median           Avg        Stddev
100        967014       1292938       1208819     1185281.8     69815.851

 967014 - 999606  : ##                                                    1% (1)
 999606 - 1032199 : ##                                                    1% (1)
1032199 - 1064791 : ############                                          6% (6)
1064791 - 1097384 : ##########                                            5% (5)
1097384 - 1129976 : ##################                                    9% (9)
1129976 - 1162568 : ####################                                 10% (10)
1162568 - 1195161 : ##########################                           13% (13)
1195161 - 1227753 : ############################################         22% (22)
1227753 - 1260346 : ##################################################   25% (25)
1260346 - 1292938 : ##############                                        7% (7)

Observations: Not much changes, ebizzy is not much impacted.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200807074517.27957-2-srikar@linux.vnet.ibm.com
4 years agosched/topology: Allow archs to override cpu_smt_mask
Srikar Dronamraju [Fri, 7 Aug 2020 07:45:16 +0000 (13:15 +0530)]
sched/topology: Allow archs to override cpu_smt_mask

cpu_smt_mask tracks topology_sibling_cpumask. This would be good for
most architectures. One of the users of cpu_smt_mask(), would be to
identify idle-cores. On Power9, a pair of SMT4 cores can be presented
by the firmware as a SMT8 core for backward compatibility reasons.

powerpc allows LPARs to be live migrated from Power8 to Power9. Do
note Power8 had only SMT8 cores. Existing software which has been
developed/configured for Power8 would expect to see SMT8 core.
Maintaining the illusion of SMT8 core is a requirement to make that
work.

In order to maintain above userspace backward compatibility with
previous versions of processor, Power9 onwards there is option to the
firmware to advertise a pair of SMT4 cores as a fused cores aka SMT8
core. On Power9 this pair shares the L2 cache as well. However, from
the scheduler's point of view, a core should be determined by SMT4,
since its a completely independent unit of compute. Hence allow
powerpc architecture to override the default cpu_smt_mask() to point
to the SMT4 cores in a SMT8 mode.

This will ensure the scheduler is always given the right information.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200807074517.27957-1-srikar@linux.vnet.ibm.com
4 years agodrivers/macintosh/smu.c: Fix undeclared symbol warning
Wang Wensheng [Mon, 14 Sep 2020 12:26:15 +0000 (12:26 +0000)]
drivers/macintosh/smu.c: Fix undeclared symbol warning

Make kernel with `C=2`:
drivers/macintosh/smu.c:1018:30: warning: symbol
'__smu_get_sdb_partition' was not declared. Should it be static?

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200914122615.65669-1-wangwensheng4@huawei.com
4 years agopowerpc/papr_scm: Fix warning triggered by perf_stats_show()
Vaibhav Jain [Sat, 12 Sep 2020 08:14:51 +0000 (13:44 +0530)]
powerpc/papr_scm: Fix warning triggered by perf_stats_show()

A warning is reported by the kernel in case perf_stats_show() returns
an error code. The warning is of the form below:

 papr_scm ibm,persistent-memory:ibm,pmemory@44100001:
    Failed to query performance stats, Err:-10
 dev_attr_show: perf_stats_show+0x0/0x1c0 [papr_scm] returned bad count
 fill_read_buffer: dev_attr_show+0x0/0xb0 returned bad count

On investigation it looks like that the compiler is silently
truncating the return value of drc_pmem_query_stats() from 'long' to
'int', since the variable used to store the return code 'rc' is an
'int'. This truncated value is then returned back as a 'ssize_t' back
from perf_stats_show() to 'dev_attr_show()' which thinks of it as a
large unsigned number and triggers this warning..

To fix this we update the type of variable 'rc' from 'int' to
'ssize_t' that prevents the compiler from truncating the return value
of drc_pmem_query_stats() and returning correct signed value back from
perf_stats_show().

Fixes: 2d02bf835e57 ("powerpc/papr_scm: Fetch nvdimm performance stats from PHYP")
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200912081451.66225-1-vaibhav@linux.ibm.com
4 years agomacintosh: windfarm: use for_each_child_of_node() macro
Qinglang Miao [Mon, 14 Sep 2020 06:14:11 +0000 (14:14 +0800)]
macintosh: windfarm: use for_each_child_of_node() macro

Use for_each_child_of_node() macro instead of open coding it.

Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200914061411.3356-1-miaoqinglang@huawei.com
4 years agopowerpc/pci: unmap legacy INTx interrupts when a PHB is removed
Cédric Le Goater [Fri, 7 Aug 2020 10:18:54 +0000 (12:18 +0200)]
powerpc/pci: unmap legacy INTx interrupts when a PHB is removed

When a passthrough IO adapter is removed from a pseries machine using
hash MMU and the XIVE interrupt mode, the POWER hypervisor expects the
guest OS to clear all page table entries related to the adapter. If
some are still present, the RTAS call which isolates the PCI slot
returns error 9001 "valid outstanding translations" and the removal of
the IO adapter fails. This is because when the PHBs are scanned, Linux
maps automatically the INTx interrupts in the Linux interrupt number
space but these are never removed.

To solve this problem, we introduce a PPC platform specific
pcibios_remove_bus() routine which clears all interrupt mappings when
the bus is removed. This also clears the associated page table entries
of the ESB pages when using XIVE.

For this purpose, we record the logical interrupt numbers of the
mapped interrupt under the PHB structure and let pcibios_remove_bus()
do the clean up.

Since some PCI adapters, like GPUs, use the "interrupt-map" property
to describe interrupt mappings other than the legacy INTx interrupts,
we can not restrict the size of the mapping array to PCI_NUM_INTX. The
number of interrupt mappings is computed from the "interrupt-map"
property and the mapping array is allocated accordingly.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200807101854.844619-1-clg@kaod.org
4 years agopowerpc/powernv/idle: add a basic stop 0-3 driver for POWER10
Nicholas Piggin [Wed, 19 Aug 2020 09:47:00 +0000 (19:47 +1000)]
powerpc/powernv/idle: add a basic stop 0-3 driver for POWER10

This driver does not restore stop > 3 state, so it limits itself
to states which do not lose full state or TB.

The POWER10 SPRs are sufficiently different from P9 that it seems
easier to split out the P10 code. The POWER10 deep sleep code
(e.g., the BHRB restore) has been taken out, but it can be re-added
when stop > 3 support is added.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Pratik Rajesh Sampat<psampat@linux.ibm.com>
Tested-by: Vaidyanathan Srinivasan <svaidy@linux.ibm.com>
Reviewed-by: Pratik Rajesh Sampat<psampat@linux.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819094700.493399-1-npiggin@gmail.com
4 years agopowerepc/book3s64/hash: Align start/end address correctly with bolt mapping
Aneesh Kumar K.V [Mon, 7 Sep 2020 07:25:39 +0000 (12:55 +0530)]
powerepc/book3s64/hash: Align start/end address correctly with bolt mapping

This ensures we don't do a partial mapping of memory. With nvdimm, when
creating namespaces with size not aligned to 16MB, the kernel ends up partially
mapping the pages. This can result in kernel adding multiple hash page table
entries for the same range. A new namespace will result in
create_section_mapping() with start and end overlapping an already existing
bolted hash page table entry.

commit: 6acd7d5ef264 ("libnvdimm/namespace: Enforce memremap_compat_align()")
made sure that we always create namespaces aligned to 16MB. But we can do
better by avoiding mapping pages that are not aligned. This helps to catch
access to these partially mapped pages early.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200907072539.67310-1-aneesh.kumar@linux.ibm.com
4 years agopowerpc/ps3: make two symbols static
Jason Yan [Fri, 11 Sep 2020 02:01:21 +0000 (10:01 +0800)]
powerpc/ps3: make two symbols static

This addresses the following sparse warning:

arch/powerpc/platforms/ps3/spu.c:451:33: warning: symbol
'spu_management_ps3_ops' was not declared. Should it be static?
arch/powerpc/platforms/ps3/spu.c:592:28: warning: symbol
'spu_priv1_ps3_ops' was not declared. Should it be static?

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200911020121.1464585-1-yanaijie@huawei.com
4 years agopowerpc/kasan: Fix CONFIG_KASAN_VMALLOC for 8xx
Christophe Leroy [Fri, 11 Sep 2020 05:05:38 +0000 (05:05 +0000)]
powerpc/kasan: Fix CONFIG_KASAN_VMALLOC for 8xx

Before the commit identified below, pages tables allocation was
performed after the allocation of final shadow area for linear memory.
But that commit switched the order, leading to page tables being
already allocated at the time 8xx kasan_init_shadow_8M() is called.
Due to this, kasan_init_shadow_8M() doesn't map the needed
shadow entries because there are already page tables.

kasan_init_shadow_8M() installs huge PMD entries instead of page
tables. We could at that time free the page tables, but there is no
point in creating page tables that get freed before being used.

Only book3s/32 hash needs early allocation of page tables. For other
variants, we can keep the initial order and create remaining page
tables after the allocation of final shadow memory for linear mem.

Move back the allocation of shadow page tables for
CONFIG_KASAN_VMALLOC into kasan_init() after the loop which creates
final shadow memory for linear mem.

Fixes: 41ea93cf7ba4 ("powerpc/kasan: Fix shadow pages allocation failure")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8ae4554357da4882612644a74387ae05525b2aaa.1599800716.git.christophe.leroy@csgroup.eu
4 years agopowerpc/powermac: Fix low_sleep_handler with KUAP and KUEP
Christophe Leroy [Fri, 11 Sep 2020 10:29:15 +0000 (10:29 +0000)]
powerpc/powermac: Fix low_sleep_handler with KUAP and KUEP

low_sleep_handler() has an hardcoded restore of segment registers
that doesn't take KUAP and KUEP into account.

Use head_32's load_segment_registers() routine instead.

Fixes: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection")
Fixes: 31ed2b13c48d ("powerpc/32s: Implement Kernel Userspace Execution Prevention.")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/21b05f7298c1b18f73e6e5b4cd5005aafa24b6da.1599820109.git.christophe.leroy@csgroup.eu
4 years agopowerpc/process: Remove useless #ifdef CONFIG_PPC_FPU
Christophe Leroy [Mon, 17 Aug 2020 05:47:58 +0000 (05:47 +0000)]
powerpc/process: Remove useless #ifdef CONFIG_PPC_FPU

Add a stub for __giveup_fpu() when CONFIG_PPC_FPU is
not selected, as done for CONFIG_SPE and CONFIG_ALTIVEC.

This allows to remove some #ifdef CONFIG_PPC_FPU.

Also change one to IS_ENABLED().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/69c8b7954ceeccc6b849e52e1fa41b3a0f10f6c1.1597643221.git.christophe.leroy@csgroup.eu
4 years agopowerpc/process: Remove useless #ifdef CONFIG_SPE
Christophe Leroy [Mon, 17 Aug 2020 05:47:57 +0000 (05:47 +0000)]
powerpc/process: Remove useless #ifdef CONFIG_SPE

cpu_has_feature(CPU_FTR_SPE) returns false when CONFIG_SPE is
not set.

There is no need to enclose the test in an #ifdef CONFIG_SPE.
Remove it.

CPU_FTR_SPE only exists on 32 bits. Define it as 0 on 64 bits.

We have a couple of places like:

 #ifdef CONFIG_SPE
if (cpu_has_feature(CPU_FTR_SPE)) {
do_something_that_requires_CONFIG_SPE
} else {
return -EINVAL;
}
 #else
return -EINVAL;
 #endif

Replace them by a cleaner version:

if (cpu_has_feature(CPU_FTR_SPE)) {
 #ifdef CONFIG_SPE
do_something_that_requires_CONFIG_SPE
 #endif
} else {
return -EINVAL;
}

When CONFIG_SPE is not set, this resolves to an unconditional
return of -EINVAL

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/698df8387555765b70ea42e4a7fa48141c309c1f.1597643221.git.christophe.leroy@csgroup.eu
4 years agopowerpc/process: Remove useless #ifdef CONFIG_ALTIVEC
Christophe Leroy [Mon, 17 Aug 2020 05:47:56 +0000 (05:47 +0000)]
powerpc/process: Remove useless #ifdef CONFIG_ALTIVEC

cpu_has_feature(CPU_FTR_ALTIVEC) returns false when CONFIG_ALTIVEC is
not set.

There is no need to enclose the test in an #ifdef CONFIG_ALTIVEC.
Remove it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/03ba6b52344ca7c336df2bc6e3d31d736c804ae2.1597643221.git.christophe.leroy@csgroup.eu
4 years agopowerpc/process: Remove useless #ifdef CONFIG_VSX
Christophe Leroy [Mon, 17 Aug 2020 05:47:55 +0000 (05:47 +0000)]
powerpc/process: Remove useless #ifdef CONFIG_VSX

cpu_has_feature(CPU_FTR_VSX) returns false when CONFIG_VSX is
not set.

There is no need to enclose the test in an #ifdef CONFIG_VSX.
Remove it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0eb61cf0dc66d781d47deb2228498cd61d03a754.1597643221.git.christophe.leroy@csgroup.eu
4 years agopowerpc/process: Tag an #endif to help locate the matching #ifdef.
Christophe Leroy [Mon, 17 Aug 2020 05:46:45 +0000 (05:46 +0000)]
powerpc/process: Tag an #endif to help locate the matching #ifdef.

That #endif is more than 100 lines after the matching #ifdef,
and there are several #ifdef/#else/#endif inbetween.

Tag it as /* CONFIG_PPC_BOOK3S_64 */ to help locate the
matching #ifdef.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/3612a8f8aaca16de3fc414a7e66293319d6e213c.1597643147.git.christophe.leroy@csgroup.eu
4 years agopowerpc/process: Replace #ifdef CONFIG_KALLSYMS by IS_ENABLED()
Christophe Leroy [Mon, 17 Aug 2020 05:46:44 +0000 (05:46 +0000)]
powerpc/process: Replace #ifdef CONFIG_KALLSYMS by IS_ENABLED()

The #ifdef CONFIG_KALLSYMS encloses some printk which can
compile in all cases.

Replace by IS_ENABLED().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2d89732a9062b2cf2651728804e4b8f6c9b9358e.1597643164.git.christophe.leroy@csgroup.eu
4 years agopowerpc/process: Replace an #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) by IS_EN...
Christophe Leroy [Mon, 17 Aug 2020 05:46:43 +0000 (05:46 +0000)]
powerpc/process: Replace an #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) by IS_ENABLED()

The #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) encloses some
printk which can be compiled in all cases.

Replace by IS_ENABLED().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a1b6ef3d657c8f249193442f56868fc358ea5b6c.1597643160.git.christophe.leroy@csgroup.eu
4 years agopowerpc/process: Replace an #ifdef CONFIG_PPC_BOOK3S_64 by IS_ENABLED()
Christophe Leroy [Mon, 17 Aug 2020 05:46:42 +0000 (05:46 +0000)]
powerpc/process: Replace an #ifdef CONFIG_PPC_BOOK3S_64 by IS_ENABLED()

This #ifdef CONFIG_PPC_BOOK3S_64 calls preload_new_slb_context()
when radix is not enabled.

radix_enabled() is always defined, and the prototype for
preload_new_slb_context() is always present, so the #ifdef
is unneeded.

Replace it by IS_ENABLED().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d31506ca9bac9def68cf7424eded63fdc4fb6660.1597643167.git.christophe.leroy@csgroup.eu
4 years agopowerpc/process: Replace an #ifdef CONFIG_PPC_47x by IS_ENABLED()
Christophe Leroy [Mon, 17 Aug 2020 05:46:41 +0000 (05:46 +0000)]
powerpc/process: Replace an #ifdef CONFIG_PPC_47x by IS_ENABLED()

isync() is always defined, no need for an #ifdef.

Replace it by IS_ENABLED(CONFIG_PPC_47x).

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ac8da0e3baa91dda805e1e492fd65aecd90c1fb5.1597643156.git.christophe.leroy@csgroup.eu
4 years agopowerpc/32: Fix vmap stack - Properly set r1 before activating MMU
Christophe Leroy [Mon, 7 Sep 2020 13:42:10 +0000 (13:42 +0000)]
powerpc/32: Fix vmap stack - Properly set r1 before activating MMU

We need r1 to be properly set before activating MMU, otherwise any new
exception taken while saving registers into the stack in exception
prologs will use the user stack, which is wrong and will even lockup
or crash when KUAP is selected.

Do that by switching the meaning of r11 and r1 until we have saved r1
to the stack: copy r1 into r11 and setup the new stack pointer in r1.
To avoid complicating and impacting all generic and specific prolog
code (and more), copy back r1 into r11 once r11 is save onto
the stack.

We could get rid of copying r1 back and forth at the cost of
rewriting everything to use r1 instead of r11 all the way when
CONFIG_VMAP_STACK is set, but the effort is probably not worth it.

Fixes: 028474876f47 ("powerpc/32: prepare for CONFIG_VMAP_STACK")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8f85e8752ac5af602db7237ef53d634f4f3d3892.1599486108.git.christophe.leroy@csgroup.eu
4 years agopowerpc/32: Fix vmap stack - Do not activate MMU before reading task struct
Christophe Leroy [Mon, 7 Sep 2020 13:42:09 +0000 (13:42 +0000)]
powerpc/32: Fix vmap stack - Do not activate MMU before reading task struct

We need r1 to be properly set before activating MMU, so
reading task_struct->stack must be done with MMU off.

This means we need an additional register to play with MSR
bits while r11 now points to the stack. For that, move r10
back to CR (As is already done for hash MMU) and use r10.

We still don't have r1 correct yet when we activate MMU.
It is done in following patch.

Fixes: 028474876f47 ("powerpc/32: prepare for CONFIG_VMAP_STACK")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a027d447022a006c9c4958ac734128e577a3c5c1.1599486108.git.christophe.leroy@csgroup.eu
4 years agopowerpc/uaccess: Remove __put_user_asm() and __put_user_asm2()
Christophe Leroy [Fri, 4 Sep 2020 11:01:32 +0000 (11:01 +0000)]
powerpc/uaccess: Remove __put_user_asm() and __put_user_asm2()

__put_user_asm() and __put_user_asm2() are not used anymore.

Remove them.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d66c4a372738d2fbd81f433ca86e4295871ace6a.1599216721.git.christophe.leroy@csgroup.eu
4 years agopowerpc/uaccess: Switch __patch_instruction() to __put_user_asm_goto()
Christophe Leroy [Fri, 4 Sep 2020 11:01:31 +0000 (11:01 +0000)]
powerpc/uaccess: Switch __patch_instruction() to __put_user_asm_goto()

__patch_instruction() is the only user of __put_user_asm() outside
of asm/uaccess.h

Switch to the new __put_user_asm_goto() to enable retirement of
__put_user_asm() in a later patch.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b9745b122f4a9ae72cef445c61320022ab8b77b7.1599216721.git.christophe.leroy@csgroup.eu
4 years agopowerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto()
Christophe Leroy [Fri, 4 Sep 2020 11:01:30 +0000 (11:01 +0000)]
powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto()

__put_user_asm_goto() provides more flexibility to GCC and avoids using
a local variable to tell if the write succeeded or not.
GCC can then avoid implementing a cmp in the fast path.

See the difference for a small function like the PPC64 version of
save_general_regs() in arch/powerpc/kernel/signal_32.c:

Before the patch (unreachable nop removed):

0000000000000c10 <.save_general_regs>:
     c10: 39 20 00 2c  li      r9,44
     c14: 39 40 00 00  li      r10,0
     c18: 7d 29 03 a6  mtctr   r9
     c1c: 38 c0 00 00  li      r6,0
     c20: 48 00 00 14  b       c34 <.save_general_regs+0x24>
     c30: 42 40 00 40  bdz     c70 <.save_general_regs+0x60>
     c34: 28 2a 00 27  cmpldi  r10,39
     c38: 7c c8 33 78  mr      r8,r6
     c3c: 79 47 1f 24  rldicr  r7,r10,3,60
     c40: 39 20 00 01  li      r9,1
     c44: 41 82 00 0c  beq     c50 <.save_general_regs+0x40>
     c48: 7d 23 38 2a  ldx     r9,r3,r7
     c4c: 79 29 00 20  clrldi  r9,r9,32
     c50: 91 24 00 00  stw     r9,0(r4)
     c54: 2c 28 00 00  cmpdi   r8,0
     c58: 39 4a 00 01  addi    r10,r10,1
     c5c: 38 84 00 04  addi    r4,r4,4
     c60: 41 82 ff d0  beq     c30 <.save_general_regs+0x20>
     c64: 38 60 ff f2  li      r3,-14
     c68: 4e 80 00 20  blr
     c70: 38 60 00 00  li      r3,0
     c74: 4e 80 00 20  blr

0000000000000000 <.fixup>:
  cc: 39 00 ff f2  li      r8,-14
  d0: 48 00 00 00  b       d0 <.fixup+0xd0>
d0: R_PPC64_REL24 .text+0xc54

After the patch:

0000000000001490 <.save_general_regs>:
    1490: 39 20 00 2c  li      r9,44
    1494: 39 40 00 00  li      r10,0
    1498: 7d 29 03 a6  mtctr   r9
    149c: 60 00 00 00  nop
    14a0: 28 2a 00 27  cmpldi  r10,39
    14a4: 79 48 1f 24  rldicr  r8,r10,3,60
    14a8: 39 20 00 01  li      r9,1
    14ac: 41 82 00 0c  beq     14b8 <.save_general_regs+0x28>
    14b0: 7d 23 40 2a  ldx     r9,r3,r8
    14b4: 79 29 00 20  clrldi  r9,r9,32
    14b8: 91 24 00 00  stw     r9,0(r4)
    14bc: 39 4a 00 01  addi    r10,r10,1
    14c0: 38 84 00 04  addi    r4,r4,4
    14c4: 42 00 ff dc  bdnz    14a0 <.save_general_regs+0x10>
    14c8: 38 60 00 00  li      r3,0
    14cc: 4e 80 00 20  blr
    14d0: 38 60 ff f2  li      r3,-14
    14d4: 4e 80 00 20  blr

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/94ba5a5138f99522e1562dbcdb38d31aa790dc89.1599216721.git.christophe.leroy@csgroup.eu
4 years agopowerpc/uaccess: Add pre-update addressing to __put_user_asm_goto()
Christophe Leroy [Fri, 4 Sep 2020 10:46:47 +0000 (10:46 +0000)]
powerpc/uaccess: Add pre-update addressing to __put_user_asm_goto()

Enable pre-update addressing mode in __put_user_asm_goto()

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/346f65d677adb11865f7762c25a1ca3c64404ba5.1599216023.git.christophe.leroy@csgroup.eu
4 years agopowerpc/8xx: Support 16k hugepages with 4k pages
Christophe Leroy [Mon, 31 Aug 2020 08:30:44 +0000 (08:30 +0000)]
powerpc/8xx: Support 16k hugepages with 4k pages

The 8xx has 4 page sizes: 4k, 16k, 512k and 8M

4k and 16k can be selected at build time as standard page sizes,
and 512k and 8M are hugepages.

When 4k standard pages are selected, 16k pages are not available.

Allow 16k pages as hugepages when 4k pages are used.

To allow that, implement arch_make_huge_pte() which receives
the necessary arguments to allow setting the PTE in accordance
with the page size:
- 512 k pages must have _PAGE_HUGE and _PAGE_SPS. They are set
by pte_mkhuge(). arch_make_huge_pte() does nothing.
- 16 k pages must have only _PAGE_SPS. arch_make_huge_pte() clears
_PAGE_HUGE.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a518abc29266a708dfbccc8fce9ae6694fe4c2c6.1598862623.git.christophe.leroy@csgroup.eu
4 years agopowerpc/8xx: Refactor calculation of number of entries per PTE in page tables
Christophe Leroy [Mon, 31 Aug 2020 08:30:43 +0000 (08:30 +0000)]
powerpc/8xx: Refactor calculation of number of entries per PTE in page tables

On 8xx, the number of entries occupied by a PTE in the page tables
depends on the size of the page. At the time being, this calculation
is done in two places: in pte_update() and in set_huge_pte_at()

Refactor this calculation into a helper called
number_of_cells_per_pte(). For the time being, the val param is
unused. It will be used by following patch.

Instead of opencoding is_hugepd(), use hugepd_ok() with a forward
declaration.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f6ea2483c2c389567b007945948f704d18cfaeea.1598862623.git.christophe.leroy@csgroup.eu
4 years agopowerpc: Fix random segfault when freeing hugetlb range
Christophe Leroy [Mon, 31 Aug 2020 07:58:19 +0000 (07:58 +0000)]
powerpc: Fix random segfault when freeing hugetlb range

The following random segfault is observed from time to time with
map_hugetlb selftest:

root@localhost:~# ./map_hugetlb 1 19
524288 kB hugepages
Mapping 1 Mbytes
Segmentation fault

[   31.219972] map_hugetlb[365]: segfault (11) at 117 nip 77974f8c lr 779a6834 code 1 in ld-2.23.so[77966000+21000]
[   31.220192] map_hugetlb[365]: code: 9421ffc0 480318d1 93410028 90010044 9361002c 93810030 93a10034 93c10038
[   31.220307] map_hugetlb[365]: code: 93e1003c 93210024 8123007c 81430038 <80e90004814a0004 7f443a14 813a0004
[   31.221911] BUG: Bad rss-counter state mm:(ptrval) type:MM_FILEPAGES val:33
[   31.229362] BUG: Bad rss-counter state mm:(ptrval) type:MM_ANONPAGES val:5

This fault is due to hugetlb_free_pgd_range() freeing page tables
that are also used by regular pages.

As explain in the comment at the beginning of
hugetlb_free_pgd_range(), the verification done in free_pgd_range()
on floor and ceiling is not done here, which means
hugetlb_free_pte_range() can free outside the expected range.

As the verification cannot be done in hugetlb_free_pgd_range(), it
must be done in hugetlb_free_pte_range().

Fixes: b250c8c08c79 ("powerpc/8xx: Manage 512k huge pages as standard pages.")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f0cb2a5477cd87d1eaadb128042e20aeb2bc2859.1598860677.git.christophe.leroy@csgroup.eu
4 years agopowerpc/tau: Disable TAU between measurements
Finn Thain [Fri, 4 Sep 2020 23:02:20 +0000 (09:02 +1000)]
powerpc/tau: Disable TAU between measurements

Enabling CONFIG_TAU_INT causes random crashes:

Unrecoverable exception 1700 at c0009414 (msr=1000)
Oops: Unrecoverable exception, sig: 6 [#1]
BE PAGE_SIZE=4K MMU=Hash SMP NR_CPUS=2 PowerMac
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-pmac-00043-gd5f545e1a8593 #5
NIP:  c0009414 LR: c0009414 CTR: c00116fc
REGS: c0799eb8 TRAP: 1700   Not tainted  (5.7.0-pmac-00043-gd5f545e1a8593)
MSR:  00001000 <ME>  CR: 22000228  XER: 00000100

GPR00: 00000000 c0799f70 c076e300 00800000 0291c0ac 00e00000 c076e300 00049032
GPR08: 00000001 c00116fc 00000000 dfbd3200 ffffffff 007f80a8 00000000 00000000
GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 c075ce04
GPR24: c075ce04 dfff8880 c07b0000 c075ce04 00080000 00000001 c079ef98 c079ef5c
NIP [c0009414] arch_cpu_idle+0x24/0x6c
LR [c0009414] arch_cpu_idle+0x24/0x6c
Call Trace:
[c0799f70] [00000001] 0x1 (unreliable)
[c0799f80] [c0060990] do_idle+0xd8/0x17c
[c0799fa0] [c0060ba4] cpu_startup_entry+0x20/0x28
[c0799fb0] [c072d220] start_kernel+0x434/0x44c
[c0799ff0] [00003860] 0x3860
Instruction dump:
XXXXXXXX XXXXXXXX XXXXXXXX 3d20c07b XXXXXXXX XXXXXXXX XXXXXXXX 7c0802a6
XXXXXXXX XXXXXXXX XXXXXXXX 4e800421 XXXXXXXX XXXXXXXX XXXXXXXX 7d2000a6
---[ end trace 3a0c9b5cb216db6b ]---

Resolve this problem by disabling each THRMn comparator when handling
the associated THRMn interrupt and by disabling the TAU entirely when
updating THRMn thresholds.

Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5a0ba3dc5612c7aac596727331284a3676c08472.1599260540.git.fthain@telegraphics.com.au
4 years agopowerpc/tau: Check processor type before enabling TAU interrupt
Finn Thain [Fri, 4 Sep 2020 23:02:20 +0000 (09:02 +1000)]
powerpc/tau: Check processor type before enabling TAU interrupt

According to Freescale's documentation, MPC74XX processors have an
erratum that prevents the TAU interrupt from working, so don't try to
use it when running on those processors.

Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c281611544768e758bd58fe812cf702a5bd2d042.1599260540.git.fthain@telegraphics.com.au
4 years agopowerpc/tau: Remove duplicated set_thresholds() call
Finn Thain [Fri, 4 Sep 2020 23:02:20 +0000 (09:02 +1000)]
powerpc/tau: Remove duplicated set_thresholds() call

The commentary at the call site seems to disagree with the code. The
conditional prevents calling set_thresholds() via the exception handler,
which appears to crash. Perhaps that's because it immediately triggers
another TAU exception. Anyway, calling set_thresholds() from TAUupdate()
is redundant because tau_timeout() does so.

Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d7c7ee33232cf72a6a6bbb6ef05838b2e2b113c0.1599260540.git.fthain@telegraphics.com.au
4 years agopowerpc/tau: Convert from timer to workqueue
Finn Thain [Fri, 4 Sep 2020 23:02:20 +0000 (09:02 +1000)]
powerpc/tau: Convert from timer to workqueue

Since commit 19dbdcb8039cf ("smp: Warn on function calls from softirq
context") the Thermal Assist Unit driver causes a warning like the
following when CONFIG_SMP is enabled.

  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 0 at kernel/smp.c:428 smp_call_function_many_cond+0xf4/0x38c
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-pmac #3
  NIP:  c00b37a8 LR: c00b3abc CTR: c001218c
  REGS: c0799c60 TRAP: 0700   Not tainted  (5.7.0-pmac)
  MSR:  00029032 <EE,ME,IR,DR,RI>  CR: 42000224  XER: 00000000
  GPR00: c00b3abc c0799d18 c076e300 c079ef5c c0011fec 00000000 00000000 00000000
  GPR08: 00000100 00000100 00008000 ffffffff 42000224 00000000 c079d040 c079d044
  GPR16: 00000001 00000000 00000004 c0799da0 c079f054 c07a0000 c07a0000 00000000
  GPR24: c0011fec 00000000 c079ef5c c079ef5c 00000000 00000000 00000000 00000000
  NIP [c00b37a8] smp_call_function_many_cond+0xf4/0x38c
  LR [c00b3abc] on_each_cpu+0x38/0x68
  Call Trace:
  [c0799d18] [ffffffff] 0xffffffff (unreliable)
  [c0799d68] [c00b3abc] on_each_cpu+0x38/0x68
  [c0799d88] [c0096704] call_timer_fn.isra.26+0x20/0x7c
  [c0799d98] [c0096b40] run_timer_softirq+0x1d4/0x3fc
  [c0799df8] [c05b4368] __do_softirq+0x118/0x240
  [c0799e58] [c0039c44] irq_exit+0xc4/0xcc
  [c0799e68] [c000ade8] timer_interrupt+0x1b0/0x230
  [c0799ea8] [c0013520] ret_from_except+0x0/0x14
  --- interrupt: 901 at arch_cpu_idle+0x24/0x6c
      LR = arch_cpu_idle+0x24/0x6c
  [c0799f70] [00000001] 0x1 (unreliable)
  [c0799f80] [c0060990] do_idle+0xd8/0x17c
  [c0799fa0] [c0060ba8] cpu_startup_entry+0x24/0x28
  [c0799fb0] [c072d220] start_kernel+0x434/0x44c
  [c0799ff0] [00003860] 0x3860
  Instruction dump:
  8129f204 2f890000 40beff98 3d20c07a 8929eec4 2f890000 40beff88 0fe00000
  81220000 552805de 550802ef 4182ff84 <0fe000003860ffff 7f65db78 7f44d378
  ---[ end trace 34a886e47819c2eb ]---

Don't call on_each_cpu() from a timer callback, call it from a worker
thread instead.

Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2")
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/bb61650bea4f4c91fb8e24b9a6f130a1438651a7.1599260540.git.fthain@telegraphics.com.au
4 years agopowerpc/tau: Use appropriate temperature sample interval
Finn Thain [Fri, 4 Sep 2020 23:02:20 +0000 (09:02 +1000)]
powerpc/tau: Use appropriate temperature sample interval

According to the MPC750 Users Manual, the SITV value in Thermal
Management Register 3 is 13 bits long. The present code calculates the
SITV value as 60 * 500 cycles. This would overflow to give 10 us on
a 500 MHz CPU rather than the intended 60 us. (But according to the
Microprocessor Datasheet, there is also a factor of 266 that has to be
applied to this value on certain parts i.e. speed sort above 266 MHz.)
Always use the maximum cycle count, as recommended by the Datasheet.

Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/896f542e5f0f1d6cf8218524c2b67d79f3d69b3c.1599260540.git.fthain@telegraphics.com.au
4 years agopowerpc/mm/book3s: Split radix and hash MAX_PHYSMEM limit
Aneesh Kumar K.V [Mon, 8 Jun 2020 07:09:04 +0000 (12:39 +0530)]
powerpc/mm/book3s: Split radix and hash MAX_PHYSMEM limit

MAX_PHYSMEM #define is used along with sparsemem to determine the SECTION_SHIFT
value. Powerpc also uses the same value to limit the max memory enabled on the
system. With 4K PAGE_SIZE and hash translation mode, we want to limit the max
memory enabled to 64TB due to page table size restrictions. However, with
radix translation, we don't have these restrictions. Hence split the radix
and hash MA_PHYSMEM limit and use different limit for each of them.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200608070904.387440-4-aneesh.kumar@linux.ibm.com
4 years agopowerpc/book3s64/hash/4k: Support large linear mapping range with 4K
Aneesh Kumar K.V [Mon, 8 Jun 2020 07:09:03 +0000 (12:39 +0530)]
powerpc/book3s64/hash/4k: Support large linear mapping range with 4K

With commit: 0034d395f89d ("powerpc/mm/hash64: Map all the kernel
regions in the same 0xc range"), we now split the 64TB address range
into 4 contexts each of 16TB. That implies we can do only 16TB linear
mapping.

On some systems, eg. Power9, memory attached to nodes > 0 will appear
above 16TB in the linear mapping. This resulted in kernel crash when
we boot such systems in hash translation mode with 4K PAGE_SIZE.

This patch updates the kernel mapping such that we now start supporting upto
61TB of memory with 4K. The kernel mapping now looks like below 4K PAGE_SIZE
and hash translation.

    vmalloc start     = 0xc0003d0000000000
    IO start          = 0xc0003e0000000000
    vmemmap start     = 0xc0003f0000000000

Our MAX_PHYSMEM_BITS for 4K is still 64TB even though we can only map 61TB.
We prevent bolt mapping anything outside 61TB range by checking against
H_VMALLOC_START.

Fixes: 0034d395f89d ("powerpc/mm/hash64: Map all the kernel regions in the same 0xc range")
Reported-by: Cameron Berkenpas <cam@neo-zeon.de>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200608070904.387440-3-aneesh.kumar@linux.ibm.com
4 years agopowerpc/64/mm: implement page mapping percpu first chunk allocator
Aneesh Kumar K.V [Mon, 8 Jun 2020 07:09:02 +0000 (12:39 +0530)]
powerpc/64/mm: implement page mapping percpu first chunk allocator

Implement page mapping percpu first chunk allocator as a fallback to
the embedding allocator. With 4K hash translation we limit our page
table range to 64TB and commit: 0034d395f89d ("powerpc/mm/hash64: Map all the
kernel regions in the same 0xc range") moved all kernel mapping to
that 64TB range. In-order to support sparse memory layout we need
to increase our linear mapping space and reduce other mappings.

With such a layout percpu embedded first chunk allocator will fail
because of small vmalloc range. Add a fallback to page mapping
percpu first chunk allocator for such failures.

The below dmesg output can be observed in such case.

 percpu: max_distance=0x1ffffef00000 too large for vmalloc space 0x10000000000
 PERCPU: auto allocator failed (-22), falling back to page size
 percpu: 40 4K pages/cpu s148816 r0 d15024

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200608070904.387440-2-aneesh.kumar@linux.ibm.com
4 years agopowerpc/percpu: Update percpu bootmem allocator
Aneesh Kumar K.V [Mon, 8 Jun 2020 07:09:01 +0000 (12:39 +0530)]
powerpc/percpu: Update percpu bootmem allocator

This update the ppc64 version to be closer to x86/sparc.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200608070904.387440-1-aneesh.kumar@linux.ibm.com
4 years agoselftests/powerpc: Tests for kernel accessing user memory
Ravi Bangoria [Wed, 2 Sep 2020 04:29:45 +0000 (09:59 +0530)]
selftests/powerpc: Tests for kernel accessing user memory

Introduce tests to cover simple scenarios where user is watching
memory which can be accessed by kernel as well. We also support
_MODE_EXACT with _SETHWDEBUG interface. Move those testcases outside
of _BP_RANGE condition. This will help to test _MODE_EXACT scenarios
when CONFIG_HAVE_HW_BREAKPOINT is not set, eg:

  $ ./ptrace-hwbreak
  ...
  PTRACE_SET_DEBUGREG, Kernel Access Userspace, len: 8: Ok
  PPC_PTRACE_SETHWDEBUG, MODE_EXACT, WO, len: 1: Ok
  PPC_PTRACE_SETHWDEBUG, MODE_EXACT, RO, len: 1: Ok
  PPC_PTRACE_SETHWDEBUG, MODE_EXACT, RW, len: 1: Ok
  PPC_PTRACE_SETHWDEBUG, MODE_EXACT, Kernel Access Userspace, len: 1: Ok
  success: ptrace-hwbreak

Suggested-by: Pedro Miraglia Franco de Carvalho <pedromfc@linux.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200902042945.129369-9-ravi.bangoria@linux.ibm.com
4 years agopowerpc/watchpoint/ptrace: Introduce PPC_DEBUG_FEATURE_DATA_BP_ARCH_31
Ravi Bangoria [Wed, 2 Sep 2020 04:29:44 +0000 (09:59 +0530)]
powerpc/watchpoint/ptrace: Introduce PPC_DEBUG_FEATURE_DATA_BP_ARCH_31

PPC_DEBUG_FEATURE_DATA_BP_ARCH_31 can be used to determine whether
we are running on an ISA 3.1 compliant machine. Which is needed to
determine DAR behaviour, 512 byte boundary limit etc. This was
requested by Pedro Miraglia Franco de Carvalho for extending
watchpoint features in gdb. Note that availability of 2nd DAWR is
independent of this flag and should be checked using
ppc_debug_info->num_data_bps.

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200902042945.129369-8-ravi.bangoria@linux.ibm.com
4 years agopowerpc/watchpoint: Add hw_len wherever missing
Ravi Bangoria [Wed, 2 Sep 2020 04:29:43 +0000 (09:59 +0530)]
powerpc/watchpoint: Add hw_len wherever missing

There are couple of places where we set len but not hw_len. For
ptrace/perf watchpoints, when CONFIG_HAVE_HW_BREAKPOINT=Y, hw_len
will be calculated and set internally while parsing watchpoint.
But when CONFIG_HAVE_HW_BREAKPOINT=N, we need to manually set
'hw_len'. Similarly for xmon as well, hw_len needs to be set
directly.

Fixes: b57aeab811db ("powerpc/watchpoint: Fix length calculation for unaligned target")
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200902042945.129369-7-ravi.bangoria@linux.ibm.com
4 years agopowerpc/watchpoint: Fix exception handling for CONFIG_HAVE_HW_BREAKPOINT=N
Ravi Bangoria [Wed, 2 Sep 2020 04:29:42 +0000 (09:59 +0530)]
powerpc/watchpoint: Fix exception handling for CONFIG_HAVE_HW_BREAKPOINT=N

On powerpc, ptrace watchpoint works in one-shot mode. i.e. kernel
disables event every time it fires and user has to re-enable it.
Also, in case of ptrace watchpoint, kernel notifies ptrace user
before executing instruction.

With CONFIG_HAVE_HW_BREAKPOINT=N, kernel is missing to disable
ptrace event and thus it's causing infinite loop of exceptions.
This is especially harmful when user watches on a data which is
also read/written by kernel, eg syscall parameters. In such case,
infinite exceptions happens in kernel mode which causes soft-lockup.

Fixes: 9422de3e953d ("powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers")
Reported-by: Pedro Miraglia Franco de Carvalho <pedromfc@linux.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200902042945.129369-6-ravi.bangoria@linux.ibm.com
4 years agopowerpc/watchpoint: Move DAWR detection logic outside of hw_breakpoint.c
Ravi Bangoria [Wed, 2 Sep 2020 04:29:41 +0000 (09:59 +0530)]
powerpc/watchpoint: Move DAWR detection logic outside of hw_breakpoint.c

Power10 hw has multiple DAWRs but hw doesn't tell which DAWR caused
the exception. So we have a sw logic to detect that in hw_breakpoint.c.
But hw_breakpoint.c gets compiled only with CONFIG_HAVE_HW_BREAKPOINT=Y.
Move DAWR detection logic outside of hw_breakpoint.c so that it can be
reused when CONFIG_HAVE_HW_BREAKPOINT is not set.

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200902042945.129369-5-ravi.bangoria@linux.ibm.com
4 years agopowerpc/watchpoint/ptrace: Fix SETHWDEBUG when CONFIG_HAVE_HW_BREAKPOINT=N
Ravi Bangoria [Wed, 2 Sep 2020 04:29:40 +0000 (09:59 +0530)]
powerpc/watchpoint/ptrace: Fix SETHWDEBUG when CONFIG_HAVE_HW_BREAKPOINT=N

When kernel is compiled with CONFIG_HAVE_HW_BREAKPOINT=N, user can
still create watchpoint using PPC_PTRACE_SETHWDEBUG, with limited
functionalities. But, such watchpoints are never firing because of
the missing privilege settings. Fix that.

It's safe to set HW_BRK_TYPE_PRIV_ALL because we don't really leak
any kernel address in signal info. Setting HW_BRK_TYPE_PRIV_ALL will
also help to find scenarios when kernel accesses user memory.

Reported-by: Pedro Miraglia Franco de Carvalho <pedromfc@linux.ibm.com>
Suggested-by: Pedro Miraglia Franco de Carvalho <pedromfc@linux.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200902042945.129369-4-ravi.bangoria@linux.ibm.com
4 years agopowerpc/watchpoint: Fix handling of vector instructions
Ravi Bangoria [Wed, 2 Sep 2020 04:29:39 +0000 (09:59 +0530)]
powerpc/watchpoint: Fix handling of vector instructions

Vector load/store instructions are special because they are always
aligned. Thus unaligned EA needs to be aligned down before comparing
it with watch ranges. Otherwise we might consider valid event as
invalid.

Fixes: 74c6881019b7 ("powerpc/watchpoint: Prepare handler to handle more than one watchpoint")
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200902042945.129369-3-ravi.bangoria@linux.ibm.com
4 years agopowerpc/watchpoint: Fix quadword instruction handling on p10 predecessors
Ravi Bangoria [Wed, 2 Sep 2020 04:29:38 +0000 (09:59 +0530)]
powerpc/watchpoint: Fix quadword instruction handling on p10 predecessors

On p10 predecessors, watchpoint with quadword access is compared at
quadword length. If the watch range is doubleword or less than that
in a first half of quadword aligned 16 bytes, and if there is any
unaligned quadword access which will access only the 2nd half, the
handler should consider it as extraneous and emulate/single-step it
before continuing.

Fixes: 74c6881019b7 ("powerpc/watchpoint: Prepare handler to handle more than one watchpoint")
Reported-by: Pedro Miraglia Franco de Carvalho <pedromfc@linux.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200902042945.129369-2-ravi.bangoria@linux.ibm.com
4 years agopowerpc/pseries/svm: Allocate SWIOTLB buffer anywhere in memory
Thiago Jung Bauermann [Tue, 18 Aug 2020 22:11:26 +0000 (19:11 -0300)]
powerpc/pseries/svm: Allocate SWIOTLB buffer anywhere in memory

POWER secure guests (i.e., guests which use the Protected Execution
Facility) need to use SWIOTLB to be able to do I/O with the
hypervisor, but they don't need the SWIOTLB memory to be in low
addresses since the hypervisor doesn't have any addressing limitation.

This solves a SWIOTLB initialization problem we are seeing in secure
guests with 128 GB of RAM: they are configured with 4 GB of
crashkernel reserved memory, which leaves no space for SWIOTLB in low
addresses.

To do this, we use mostly the same code as swiotlb_init(), but
allocate the buffer using memblock_alloc() instead of
memblock_alloc_low().

Fixes: 2efbc58f157a ("powerpc/pseries/svm: Force SWIOTLB for secure guests")
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200818221126.391073-1-bauerman@linux.ibm.com
4 years agopowerpc/64: Make VDSO32 track COMPAT on 64-bit
Michael Ellerman [Thu, 27 Aug 2020 13:17:13 +0000 (23:17 +1000)]
powerpc/64: Make VDSO32 track COMPAT on 64-bit

When we added the VDSO32 kconfig symbol, which controls building of
the 32-bit VDSO, we made it depend on CPU_BIG_ENDIAN (for 64-bit).

That was because back then COMPAT was always enabled for 64-bit, so
depending on it would have left the 32-bit VDSO always enabled, which
we didn't want.

But since then we have made COMPAT selectable, and off by default for
ppc64le, so VDSO32 should really depend on that.

For most people this makes no difference, none of the defconfigs
change, it's only if someone is building ppc64le with COMPAT=y, they
will now also get VDSO32. If they've enabled COMPAT in order to run
32-bit binaries they presumably also want the 32-bit VDSO.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/r/20200908125850.407939-1-mpe@ellerman.id.au
4 years agoMerge branch 'fixes' into next
Michael Ellerman [Mon, 14 Sep 2020 12:57:18 +0000 (22:57 +1000)]
Merge branch 'fixes' into next

Bring in our fixes branch for this cycle which avoids some small
conflicts with upcoming commits.

4 years agopowerpc/papr_scm: Limit the readability of 'perf_stats' sysfs attribute
Vaibhav Jain [Mon, 7 Sep 2020 11:05:40 +0000 (16:35 +0530)]
powerpc/papr_scm: Limit the readability of 'perf_stats' sysfs attribute

The newly introduced 'perf_stats' attribute uses the default access
mode of 0444, allowing non-root users to access performance stats of
an nvdimm and potentially force the kernel into issuing a large number
of expensive hypercalls. Since the information exposed by this
attribute cannot be cached it is better to ward off access to this
attribute from users who don't need to access to these performance
statistics.

Hence update the access mode of 'perf_stats' attribute to be only
readable by root users.

Fixes: 2d02bf835e57 ("powerpc/papr_scm: Fetch nvdimm performance stats from PHYP")
Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200907110540.21349-1-vaibhav@linux.ibm.com
4 years agopowerpc/64s: handle ISA v3.1 local copy-paste context switches
Nicholas Piggin [Tue, 25 Aug 2020 07:55:35 +0000 (17:55 +1000)]
powerpc/64s: handle ISA v3.1 local copy-paste context switches

The ISA v3.1 the copy-paste facility has a new memory move functionality
which allows the copy buffer to be pasted to domestic memory (RAM) as
opposed to foreign memory (accelerator).

This means the POWER9 trick of avoiding the cp_abort on context switch if
the process had not mapped foreign memory does not work on POWER10. Do the
cp_abort unconditionally there.

KVM must also cp_abort on guest exit to prevent copy buffer state leaking
between contexts.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200825075535.224536-1-npiggin@gmail.com
4 years agopowerpc: Warn about use of smt_snooze_delay
Joel Stanley [Wed, 2 Sep 2020 00:00:11 +0000 (09:30 +0930)]
powerpc: Warn about use of smt_snooze_delay

It's not done anything for a long time. Save the percpu variable, and
emit a warning to remind users to not expect it to do anything.

This uses pr_warn_once instead of pr_warn_ratelimit as testing
'ppc64_cpu --smt=off' on a 24 core / 4 SMT system showed the warning
to be noisy, as the online/offline loop is slow.

Fixes: 3fa8cad82b94 ("powerpc/pseries/cpuidle: smt-snooze-delay cleanup.")
Cc: stable@vger.kernel.org # v3.14
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200902000012.3440389-1-joel@jms.id.au
4 years agopowerpc/powernv: Print helpful message when cores guarded
Joel Stanley [Thu, 1 Aug 2019 05:16:30 +0000 (14:46 +0930)]
powerpc/powernv: Print helpful message when cores guarded

Often the firmware will guard out cores after a crash. This often
undesirable, and is not immediately noticeable.

This adds an informative message when a CPU device tree nodes are
marked bad in the device tree.

Signed-off-by: Joel Stanley <joel@jms.id.au>
[mpe: Use an eye-catcher that's less likely to get us in trouble]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190801051630.5804-1-joel@jms.id.au
4 years agopowerpc/pseries/iommu: Allow bigger 64bit window by removing default DMA window
Leonardo Bras [Wed, 5 Aug 2020 03:04:55 +0000 (00:04 -0300)]
powerpc/pseries/iommu: Allow bigger 64bit window by removing default DMA window

On LoPAR "DMA Window Manipulation Calls", it's recommended to remove the
default DMA window for the device, before attempting to configure a DDW,
in order to make the maximum resources available for the next DDW to be
created.

This is a requirement for using DDW on devices in which hypervisor
allows only one DMA window.

If setting up a new DDW fails anywhere after the removal of this
default DMA window, it's needed to restore the default DMA window.
For this, an implementation of ibm,reset-pe-dma-windows rtas call is
needed:

Platforms supporting the DDW option starting with LoPAR level 2.7 implement
ibm,ddw-extensions. The first extension available (index 2) carries the
token for ibm,reset-pe-dma-windows rtas call, which is used to restore
the default DMA window for a device, if it has been deleted.

It does so by resetting the TCE table allocation for the PE to it's
boot time value, available in "ibm,dma-window" device tree node.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Tested-by: David Dai <zdai@linux.vnet.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200805030455.123024-5-leobras.c@gmail.com
4 years agopowerpc/pseries/iommu: Move window-removing part of remove_ddw into remove_dma_window
Leonardo Bras [Wed, 5 Aug 2020 03:04:54 +0000 (00:04 -0300)]
powerpc/pseries/iommu: Move window-removing part of remove_ddw into remove_dma_window

Move the window-removing part of remove_ddw into a new function
(remove_dma_window), so it can be used to remove other DMA windows.

It's useful for removing DMA windows that don't create DIRECT64_PROPNAME
property, like the default DMA window from the device, which uses
"ibm,dma-window".

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Tested-by: David Dai <zdai@linux.vnet.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200805030455.123024-4-leobras.c@gmail.com
4 years agopowerpc/pseries/iommu: Update call to ibm, query-pe-dma-windows
Leonardo Bras [Wed, 5 Aug 2020 03:04:53 +0000 (00:04 -0300)]
powerpc/pseries/iommu: Update call to ibm, query-pe-dma-windows

>From LoPAR level 2.8, "ibm,ddw-extensions" index 3 can make the number of
outputs from "ibm,query-pe-dma-windows" go from 5 to 6.

This change of output size is meant to expand the address size of
largest_available_block PE TCE from 32-bit to 64-bit, which ends up
shifting page_size and migration_capable.

This ends up requiring the update of
ddw_query_response->largest_available_block from u32 to u64, and manually
assigning the values from the buffer into this struct, according to
output size.

Also, a routine was created for helping reading the ddw extensions as
suggested by LoPAR: First reading the size of the extension array from
index 0, checking if the property exists, and then returning it's value.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Tested-by: David Dai <zdai@linux.vnet.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200805030455.123024-3-leobras.c@gmail.com
4 years agopowerpc/pseries/iommu: Create defines for operations in ibm, ddw-applicable
Leonardo Bras [Wed, 5 Aug 2020 03:04:52 +0000 (00:04 -0300)]
powerpc/pseries/iommu: Create defines for operations in ibm, ddw-applicable

Create defines to help handling ibm,ddw-applicable values, avoiding
confusion about the index of given operations.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Tested-by: David Dai <zdai@linux.vnet.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200805030455.123024-2-leobras.c@gmail.com
4 years agopowerpc: Update documentation of ISA versions for Power10
Jordan Niethe [Thu, 27 Aug 2020 04:05:56 +0000 (14:05 +1000)]
powerpc: Update documentation of ISA versions for Power10

Update the CPU to ISA Version Mapping document to include Power10 and
ISA v3.1.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
[mpe: Make sure ISA reference is unique]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200827040556.1783-1-jniethe5@gmail.com
4 years agopowerpc/tools: Remove 90 line limit in checkpatch script
Russell Currey [Fri, 28 Aug 2020 02:05:42 +0000 (12:05 +1000)]
powerpc/tools: Remove 90 line limit in checkpatch script

As of commit bdc48fa11e46, scripts/checkpatch.pl now has a default line
length warning of 100 characters.  The powerpc wrapper script was using
a length of 90 instead of 80 in order to make checkpatch less
restrictive, but now it's making it more restrictive instead.

I think it makes sense to just use the default value now.

Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200828020542.393022-1-ruscur@russell.cc
4 years agoselftests/powerpc: Fix prefixes in alignment_handler signal handler
Jordan Niethe [Mon, 24 Aug 2020 13:12:31 +0000 (23:12 +1000)]
selftests/powerpc: Fix prefixes in alignment_handler signal handler

The signal handler in the alignment handler self test has the ability
to jump over the instruction that triggered the signal. It does this
by incrementing the PT_NIP in the user context by 4. If it were a
prefixed instruction this will mean that the suffix is then executed
which is incorrect. Instead check if the major opcode indicates a
prefixed instruction (e.g. it is 1) and if so increment PT_NIP by 8.

If ISA v3.1 is not available treat it as a word instruction even if
the major opcode is 1.

Fixes: 620a6473df36 ("selftests/powerpc: Add prefixed loads/stores to alignment_handler test")
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
[mpe: Fix 32-bit build, rename haveprefixes to prefixes_enabled]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200824131231.14008-1-jniethe5@gmail.com
4 years agopowerpc/boot: Update Makefile comment for 64bit wrapper
Jordan Niethe [Tue, 25 Aug 2020 03:51:47 +0000 (13:51 +1000)]
powerpc/boot: Update Makefile comment for 64bit wrapper

As of commit 147c05168fc8 ("powerpc/boot: Add support for 64bit little
endian wrapper") the comment in the Makefile is misleading. The wrapper
packaging 64bit kernel may built as a 32 or 64 bit elf. Update the
comment to reflect this.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200825035147.3239-1-jniethe5@gmail.com
4 years agopowerpc/64: Remove unused generic_secondary_thread_init()
Michael Ellerman [Wed, 19 Aug 2020 01:57:04 +0000 (11:57 +1000)]
powerpc/64: Remove unused generic_secondary_thread_init()

The last caller was removed in 2014 in commit fb5a515704d7 ("powerpc:
Remove platforms/wsp and associated pieces").

As Jordan noticed even though there are no callers, the code above in
fsl_secondary_thread_init() falls through into
generic_secondary_thread_init(). So we can remove the _GLOBAL but not
the body of the function.

However because fsl_secondary_thread_init() is inside #ifdef
CONFIG_PPC_BOOK3E, we can never reach the body of
generic_secondary_thread_init() unless CONFIG_PPC_BOOK3E is enabled,
so we can wrap the whole thing in a single #ifdef.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819015704.1976364-1-mpe@ellerman.id.au
4 years agoselftests/powerpc: Properly handle failure in switch_endian_test
Michael Ellerman [Wed, 19 Aug 2020 01:57:27 +0000 (11:57 +1000)]
selftests/powerpc: Properly handle failure in switch_endian_test

On older CPUs the switch_endian() syscall doesn't work. Currently that
causes the switch_endian_test to just crash. Instead detect the
failure and properly exit with a failure message.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819015727.1977134-9-mpe@ellerman.id.au
4 years agoselftests/powerpc: Don't touch VMX/VSX on older CPUs
Michael Ellerman [Wed, 19 Aug 2020 01:57:26 +0000 (11:57 +1000)]
selftests/powerpc: Don't touch VMX/VSX on older CPUs

If we're running on a CPU without VMX/VSX then don't touch them. This
is fragile, the compiler could spill a VMX/VSX register and break the
test anyway. But in practice it seems to work, ie. the test runs to
completion on a system without VSX with this change.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819015727.1977134-8-mpe@ellerman.id.au
4 years agoselftests/powerpc: Skip L3 bank test on older CPUs
Michael Ellerman [Wed, 19 Aug 2020 01:57:25 +0000 (11:57 +1000)]
selftests/powerpc: Skip L3 bank test on older CPUs

This is a test of specific piece of logic in isa207-common.c, which is
only used on Power8 or later. So skip it on older CPUs.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819015727.1977134-7-mpe@ellerman.id.au
4 years agoselftests/powerpc: Skip security tests on older CPUs
Michael Ellerman [Wed, 19 Aug 2020 01:57:24 +0000 (11:57 +1000)]
selftests/powerpc: Skip security tests on older CPUs

Both these tests use PMU events that only work on newer CPUs, so skip
them on older CPUs.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819015727.1977134-6-mpe@ellerman.id.au
4 years agoselftests/powerpc: Don't run DSCR tests on old systems
Michael Ellerman [Wed, 19 Aug 2020 01:57:23 +0000 (11:57 +1000)]
selftests/powerpc: Don't run DSCR tests on old systems

The DSCR tests fail on systems that don't have DSCR, so check for the
DSCR in hwcap and skip if it's not present.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819015727.1977134-5-mpe@ellerman.id.au
4 years agoselftests/powerpc: Include asm/cputable.h from utils.h
Michael Ellerman [Wed, 19 Aug 2020 01:57:22 +0000 (11:57 +1000)]
selftests/powerpc: Include asm/cputable.h from utils.h

utils.h provides have_hwcap() and have_hwcap2() which check for a
feature bit. Those bits are defined in asm/cputable.h, so include it
in utils.h so users of utils.h don't have to do it manually.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819015727.1977134-4-mpe@ellerman.id.au
4 years agoselftests/powerpc: Move set_dscr() into rfi_flush.c
Michael Ellerman [Wed, 19 Aug 2020 01:57:21 +0000 (11:57 +1000)]
selftests/powerpc: Move set_dscr() into rfi_flush.c

This version of set_dscr() was added for the RFI flush test, and is
fairly specific to it. It also clashes with the version of set_dscr()
in dscr/dscr.h. So move it into the RFI flush test where it's used.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819015727.1977134-3-mpe@ellerman.id.au
4 years agoselftests/powerpc: Give the bad_accesses test longer to run
Michael Ellerman [Wed, 19 Aug 2020 01:57:20 +0000 (11:57 +1000)]
selftests/powerpc: Give the bad_accesses test longer to run

On older systems this test takes longer to run (duh), give it five
minutes which is long enough on a G5 970FX @ 1.6GHz.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819015727.1977134-2-mpe@ellerman.id.au
4 years agoselftests/powerpc: Make using_hash_mmu() work on Cell & PowerMac
Michael Ellerman [Wed, 19 Aug 2020 01:57:19 +0000 (11:57 +1000)]
selftests/powerpc: Make using_hash_mmu() work on Cell & PowerMac

These platforms don't show the MMU in /proc/cpuinfo, but they always
use hash, so teach using_hash_mmu() that.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819015727.1977134-1-mpe@ellerman.id.au
4 years agoselftests/powerpc: Run tm-tmspr test for longer
Michael Ellerman [Thu, 13 Aug 2020 01:34:45 +0000 (11:34 +1000)]
selftests/powerpc: Run tm-tmspr test for longer

This test creates some threads, which write to TM SPRs, and then makes
sure the registers maintain the correct values across context switches
and contention with other threads.

But currently the test finishes almost instantaneously, which reduces
the chance of it hitting an interesting condition.

So increase the number of loops, so it runs a bit longer, though still
less than 2s on a Power8.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200813013445.686464-3-mpe@ellerman.id.au
4 years agoselftests/powerpc: Don't use setaffinity in tm-tmspr
Michael Ellerman [Thu, 13 Aug 2020 01:34:44 +0000 (11:34 +1000)]
selftests/powerpc: Don't use setaffinity in tm-tmspr

This test tries to set affinity to CPUs that don't exist, especially
if the set of online CPUs doesn't start at 0.

But there's no real reason for it to use setaffinity in the first
place, it's just trying to create lots of threads to cause contention.
So drop the setaffinity entirely.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200813013445.686464-2-mpe@ellerman.id.au
4 years agoselftests/powerpc: Fix TM tests when CPU 0 is offline
Michael Ellerman [Thu, 13 Aug 2020 01:34:43 +0000 (11:34 +1000)]
selftests/powerpc: Fix TM tests when CPU 0 is offline

Several of the TM tests fail spuriously if CPU 0 is offline, because
they blindly try to affinitise to CPU 0.

Fix them by picking any online CPU and using that instead.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200813013445.686464-1-mpe@ellerman.id.au
4 years agopowerpc/pseries/eeh: Fix dumb linebreaks
Oliver O'Halloran [Tue, 18 Aug 2020 04:45:57 +0000 (14:45 +1000)]
powerpc/pseries/eeh: Fix dumb linebreaks

These annoy me every time I see them. Why are they here? They're not even
needed for 80cols compliance.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200818044557.135497-1-oohall@gmail.com
4 years agopowerpc/process: Remove unnecessary #ifdef CONFIG_FUNCTION_GRAPH_TRACER
Christophe Leroy [Mon, 17 Aug 2020 05:46:39 +0000 (05:46 +0000)]
powerpc/process: Remove unnecessary #ifdef CONFIG_FUNCTION_GRAPH_TRACER

ftrace_graph_ret_addr() is always defined and returns 'ip' when
CONFIG_FUNCTION GRAPH_TRACER is not set.

So the #ifdef is not needed, remove it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/9d11143d4e27ba8274369a926968756917584868.1597643153.git.christophe.leroy@csgroup.eu
4 years agopowerpc/uaccess: Add pre-update addressing to __get_user_asm() and __put_user_asm()
Christophe Leroy [Wed, 12 Aug 2020 12:25:17 +0000 (12:25 +0000)]
powerpc/uaccess: Add pre-update addressing to __get_user_asm() and __put_user_asm()

Enable pre-update addressing mode in __get_user_asm() and __put_user_asm()

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/13041c7df39e89ddf574ea0cdc6dedfdd9734140.1597235091.git.christophe.leroy@csgroup.eu
4 years agocpuidle: pseries: Fix CEDE latency conversion from tb to us
Gautham R. Shenoy [Thu, 3 Sep 2020 09:27:27 +0000 (14:57 +0530)]
cpuidle: pseries: Fix CEDE latency conversion from tb to us

Commit d947fb4c965c ("cpuidle: pseries: Fixup exit latency for
CEDE(0)") sets the exit latency of CEDE(0) based on the latency values
of the Extended CEDE states advertised by the platform. The values
advertised by the platform are in timebase ticks. However the cpuidle
framework requires the latency values in microseconds.

If the tb-ticks value advertised by the platform correspond to a value
smaller than 1us, during the conversion from tb-ticks to microseconds,
in the current code, the result becomes zero. This is incorrect as it
puts a CEDE state on par with the snooze state.

This patch fixes this by rounding up the result obtained while
converting the latency value from tb-ticks to microseconds. It also
prints a warning in case we discover an extended-cede state with
wakeup latency to be 0. In such a case, ensure that CEDE(0) has a
non-zero wakeup latency.

Fixes: d947fb4c965c ("cpuidle: pseries: Fixup exit latency for CEDE(0)")
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1599125247-28488-1-git-send-email-ego@linux.vnet.ibm.com
4 years agopowerpc/dma: Fix dma_map_ops::get_required_mask
Alexey Kardashevskiy [Tue, 8 Sep 2020 01:51:06 +0000 (11:51 +1000)]
powerpc/dma: Fix dma_map_ops::get_required_mask

There are 2 problems with it:
  1. "<" vs expected "<<"
  2. the shift number is an IOMMU page number mask, not an address
  mask as the IOMMU page shift is missing.

This did not hit us before f1565c24b596 ("powerpc: use the generic
dma_ops_bypass mode") because we had additional code to handle bypass
mask so this chunk (almost?) never executed.However there were
reports that aacraid does not work with "iommu=nobypass".

After f1565c24b596, aacraid (and probably others which call
dma_get_required_mask() before setting the mask) was unable to enable
64bit DMA and fall back to using IOMMU which was known not to work,
one of the problems is double free of an IOMMU page.

This fixes DMA for aacraid, both with and without "iommu=nobypass" in
the kernel command line. Verified with "stress-ng -d 4".

Fixes: 6a5c7be5e484 ("powerpc: Override dma_get_required_mask by platform hook and ops")
Cc: stable@vger.kernel.org # v3.2+
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200908015106.79661-1-aik@ozlabs.ru
4 years agoRevert "powerpc/build: vdso linker warning for orphan sections"
Michael Ellerman [Wed, 2 Sep 2020 12:14:39 +0000 (22:14 +1000)]
Revert "powerpc/build: vdso linker warning for orphan sections"

This reverts commit f2af201002a8bc22500c04cc474ea480bf361351.

It added a usage of cc-ldoption, but cc-ldoption was removed in commit
055efab3120b ("kbuild: drop support for cc-ldoption").

Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
4 years agopowerpc/mm: Remove DEBUG_VM_PGTABLE support on powerpc
Aneesh Kumar K.V [Wed, 2 Sep 2020 04:01:22 +0000 (09:31 +0530)]
powerpc/mm: Remove DEBUG_VM_PGTABLE support on powerpc

The test is broken w.r.t page table update rules and results in kernel
crash as below. Disable the support until we get the tests updated.

[   21.083519] kernel BUG at arch/powerpc/mm/pgtable.c:304!
cpu 0x0: Vector: 700 (Program Check) at [c000000c6d1e76c0]
    pc: c00000000009a5ec: assert_pte_locked+0x14c/0x380
    lr: c0000000005eeeec: pte_update+0x11c/0x190
    sp: c000000c6d1e7950
   msr: 8000000002029033
  current = 0xc000000c6d172c80
  paca    = 0xc000000003ba0000   irqmask: 0x03   irq_happened: 0x01
    pid   = 1, comm = swapper/0
kernel BUG at arch/powerpc/mm/pgtable.c:304!
[link register   ] c0000000005eeeec pte_update+0x11c/0x190
[c000000c6d1e79500000000000000001 (unreliable)
[c000000c6d1e79b0c0000000005eee14 pte_update+0x44/0x190
[c000000c6d1e7a10c000000001a2ca9c pte_advanced_tests+0x160/0x3d8
[c000000c6d1e7ab0c000000001a2d4fc debug_vm_pgtable+0x7e8/0x1338
[c000000c6d1e7ba0c0000000000116ec do_one_initcall+0xac/0x5f0
[c000000c6d1e7c80c0000000019e4fac kernel_init_freeable+0x4dc/0x5a4
[c000000c6d1e7db0c000000000012474 kernel_init+0x24/0x160
[c000000c6d1e7e20c00000000000cbd0 ret_from_kernel_thread+0x5c/0x6c

With DEBUG_VM disabled

[   20.530152] BUG: Kernel NULL pointer dereference on read at 0x00000000
[   20.530183] Faulting instruction address: 0xc0000000000df330
cpu 0x33: Vector: 380 (Data SLB Access) at [c000000c6d19f700]
    pc: c0000000000df330: memset+0x68/0x104
    lr: c00000000009f6d8: hash__pmdp_huge_get_and_clear+0xe8/0x1b0
    sp: c000000c6d19f990
   msr: 8000000002009033
   dar: 0
  current = 0xc000000c6d177480
  paca    = 0xc00000001ec4f400   irqmask: 0x03   irq_happened: 0x01
    pid   = 1, comm = swapper/0
[link register   ] c00000000009f6d8 hash__pmdp_huge_get_and_clear+0xe8/0x1b0
[c000000c6d19f990c00000000009f748 hash__pmdp_huge_get_and_clear+0x158/0x1b0 (unreliable)
[c000000c6d19fa10c0000000019ebf30 pmd_advanced_tests+0x1f0/0x378
[c000000c6d19fab0c0000000019ed088 debug_vm_pgtable+0x79c/0x1244
[c000000c6d19fba0c0000000000116ec do_one_initcall+0xac/0x5f0
[c000000c6d19fc80c0000000019a4fac kernel_init_freeable+0x4dc/0x5a4
[c000000c6d19fdb0c000000000012474 kernel_init+0x24/0x160
[c000000c6d19fe20c00000000000cbd0 ret_from_kernel_thread+0x5c/0x6c
33:mon>

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200902040122.136414-1-aneesh.kumar@linux.ibm.com
4 years agopowerpc/uaccess: Use flexible addressing with __put_user()/__get_user()
Christophe Leroy [Wed, 12 Aug 2020 12:25:16 +0000 (12:25 +0000)]
powerpc/uaccess: Use flexible addressing with __put_user()/__get_user()

At the time being, __put_user()/__get_user() and friends only use
D-form addressing, with 0 offset. Ex:

lwz reg1, 0(reg2)

Give the compiler the opportunity to use other adressing modes
whenever possible, to get more optimised code.

Hereunder is a small exemple:

struct test {
u32 item1;
u16 item2;
u8 item3;
u64 item4;
};

int set_test_user(struct test __user *from, struct test __user *to)
{
int err;
u32 item1;
u16 item2;
u8 item3;
u64 item4;

err = __get_user(item1, &from->item1);
err |= __get_user(item2, &from->item2);
err |= __get_user(item3, &from->item3);
err |= __get_user(item4, &from->item4);

err |= __put_user(item1, &to->item1);
err |= __put_user(item2, &to->item2);
err |= __put_user(item3, &to->item3);
err |= __put_user(item4, &to->item4);

return err;
}

Before the patch:

00000df0 <set_test_user>:
 df0: 94 21 ff f0  stwu    r1,-16(r1)
 df4: 39 40 00 00  li      r10,0
 df8: 93 c1 00 08  stw     r30,8(r1)
 dfc: 93 e1 00 0c  stw     r31,12(r1)
 e00: 7d 49 53 78  mr      r9,r10
 e04: 80 a3 00 00  lwz     r5,0(r3)
 e08: 38 e3 00 04  addi    r7,r3,4
 e0c: 7d 46 53 78  mr      r6,r10
 e10: a0 e7 00 00  lhz     r7,0(r7)
 e14: 7d 29 33 78  or      r9,r9,r6
 e18: 39 03 00 06  addi    r8,r3,6
 e1c: 7d 46 53 78  mr      r6,r10
 e20: 89 08 00 00  lbz     r8,0(r8)
 e24: 7d 29 33 78  or      r9,r9,r6
 e28: 38 63 00 08  addi    r3,r3,8
 e2c: 7d 46 53 78  mr      r6,r10
 e30: 83 c3 00 00  lwz     r30,0(r3)
 e34: 83 e3 00 04  lwz     r31,4(r3)
 e38: 7d 29 33 78  or      r9,r9,r6
 e3c: 7d 43 53 78  mr      r3,r10
 e40: 90 a4 00 00  stw     r5,0(r4)
 e44: 7d 29 1b 78  or      r9,r9,r3
 e48: 38 c4 00 04  addi    r6,r4,4
 e4c: 7d 43 53 78  mr      r3,r10
 e50: b0 e6 00 00  sth     r7,0(r6)
 e54: 7d 29 1b 78  or      r9,r9,r3
 e58: 38 e4 00 06  addi    r7,r4,6
 e5c: 7d 43 53 78  mr      r3,r10
 e60: 99 07 00 00  stb     r8,0(r7)
 e64: 7d 23 1b 78  or      r3,r9,r3
 e68: 38 84 00 08  addi    r4,r4,8
 e6c: 93 c4 00 00  stw     r30,0(r4)
 e70: 93 e4 00 04  stw     r31,4(r4)
 e74: 7c 63 53 78  or      r3,r3,r10
 e78: 83 c1 00 08  lwz     r30,8(r1)
 e7c: 83 e1 00 0c  lwz     r31,12(r1)
 e80: 38 21 00 10  addi    r1,r1,16
 e84: 4e 80 00 20  blr

After the patch:

00000dbc <set_test_user>:
 dbc: 39 40 00 00  li      r10,0
 dc0: 7d 49 53 78  mr      r9,r10
 dc4: 80 03 00 00  lwz     r0,0(r3)
 dc8: 7d 48 53 78  mr      r8,r10
 dcc: a1 63 00 04  lhz     r11,4(r3)
 dd0: 7d 29 43 78  or      r9,r9,r8
 dd4: 7d 48 53 78  mr      r8,r10
 dd8: 88 a3 00 06  lbz     r5,6(r3)
 ddc: 7d 29 43 78  or      r9,r9,r8
 de0: 7d 48 53 78  mr      r8,r10
 de4: 80 c3 00 08  lwz     r6,8(r3)
 de8: 80 e3 00 0c  lwz     r7,12(r3)
 dec: 7d 29 43 78  or      r9,r9,r8
 df0: 7d 43 53 78  mr      r3,r10
 df4: 90 04 00 00  stw     r0,0(r4)
 df8: 7d 29 1b 78  or      r9,r9,r3
 dfc: 7d 43 53 78  mr      r3,r10
 e00: b1 64 00 04  sth     r11,4(r4)
 e04: 7d 29 1b 78  or      r9,r9,r3
 e08: 7d 43 53 78  mr      r3,r10
 e0c: 98 a4 00 06  stb     r5,6(r4)
 e10: 7d 23 1b 78  or      r3,r9,r3
 e14: 90 c4 00 08  stw     r6,8(r4)
 e18: 90 e4 00 0c  stw     r7,12(r4)
 e1c: 7c 63 53 78  or      r3,r3,r10
 e20: 4e 80 00 20  blr

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c27bc4e598daf3bbb225de7a1f5c52121cf1e279.1597235091.git.christophe.leroy@csgroup.eu
4 years agopowerpc: Remove flush_instruction_cache() on 8xx
Christophe Leroy [Fri, 14 Aug 2020 05:49:29 +0000 (05:49 +0000)]
powerpc: Remove flush_instruction_cache() on 8xx

flush_instruction_cache() is never used on 8xx, remove it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/245cabd8f291facac8c8c5fd370e361a69e02860.1597384145.git.christophe.leroy@csgroup.eu
4 years agopowerpc: unrel_branch_check.sh: enable the use of llvm-objdump v9, 10 or 11
Stephen Rothwell [Wed, 12 Aug 2020 08:10:36 +0000 (18:10 +1000)]
powerpc: unrel_branch_check.sh: enable the use of llvm-objdump v9, 10 or 11

Currently, using llvm-objtool, this script just silently succeeds without
actually do the intended checking.  So this updates it to work properly.

Firstly, llvm-objdump does not add target symbol names to the end
of branches in its asm output, so we have to drop the branch to
__start_initialization_multiplatform using its address.

Secondly, v9 and 10 specify branch targets as .+<offset>, so we convert
those to actual addresses.

Thirdly, v10 and 11 error out on a vmlinux if given the -R option
complaining that it is "not a dynamic object".  The -R does not make
any difference to the asm output, so remove it.

Lastly, v11 produces asm that is very similar to Gnu objtool (at least
as far as branches are concerned), so no further changes are necessary
to make it work.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200812081036.7969-3-sfr@canb.auug.org.au
4 years agopowerpc: unrel_branch_check.sh: use nm to find symbol value
Stephen Rothwell [Wed, 12 Aug 2020 08:10:35 +0000 (18:10 +1000)]
powerpc: unrel_branch_check.sh: use nm to find symbol value

This is considerably faster then parsing the objdump asm output.  It will
also make the enabling of llvm-objdump a little easier.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200812081036.7969-2-sfr@canb.auug.org.au
4 years agopowerpc: unrel_branch_check.sh: exit silently for early errors
Stephen Rothwell [Tue, 11 Aug 2020 14:04:34 +0000 (00:04 +1000)]
powerpc: unrel_branch_check.sh: exit silently for early errors

If we can't find the address of __end_interrupts, then we still exit
successfully as that is the current behaviour.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200811140435.20957-8-sfr@canb.auug.org.au
4 years agopowerpc: unrel_branch_check.sh: fix up the file header
Stephen Rothwell [Tue, 11 Aug 2020 14:04:33 +0000 (00:04 +1000)]
powerpc: unrel_branch_check.sh: fix up the file header

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200811140435.20957-7-sfr@canb.auug.org.au
4 years agopowerpc: unrel_branch_check.sh: simplify and tidy up the final loop
Stephen Rothwell [Tue, 11 Aug 2020 14:04:32 +0000 (00:04 +1000)]
powerpc: unrel_branch_check.sh: simplify and tidy up the final loop

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200811140435.20957-6-sfr@canb.auug.org.au
4 years agopowerpc: unrel_branch_check.sh: convert grep | sed | awk to just sed
Stephen Rothwell [Tue, 11 Aug 2020 14:04:31 +0000 (00:04 +1000)]
powerpc: unrel_branch_check.sh: convert grep | sed | awk to just sed

Also start using sed -E and make all the separate expressions into a
single one with comments.  Pull the stripping of condition registers
back into the sed command.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200811140435.20957-5-sfr@canb.auug.org.au
4 years agopowerpc: unrel_branch_check.sh: simplify objdump's asm output
Stephen Rothwell [Tue, 11 Aug 2020 14:04:30 +0000 (00:04 +1000)]
powerpc: unrel_branch_check.sh: simplify objdump's asm output

We don't use the raw hex instruction dump, so elide it and adjust the
following expressions.

Also use \s instead of [[:space:]] everywhere.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200811140435.20957-4-sfr@canb.auug.org.au
4 years agopowerpc: unrel_branch_check.sh: simplify and combine some executions
Stephen Rothwell [Tue, 11 Aug 2020 14:04:29 +0000 (00:04 +1000)]
powerpc: unrel_branch_check.sh: simplify and combine some executions

Also some minor style changes.

There should still be no change in behaviour.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200811140435.20957-3-sfr@canb.auug.org.au
4 years agopowerpc: unrel_branch_check.sh: fix shellcheck complaints
Stephen Rothwell [Tue, 11 Aug 2020 14:04:28 +0000 (00:04 +1000)]
powerpc: unrel_branch_check.sh: fix shellcheck complaints

No functional change

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200811140435.20957-2-sfr@canb.auug.org.au
4 years agopseries/drmem: don't cache node id in drmem_lmb struct
Scott Cheloha [Tue, 11 Aug 2020 01:51:15 +0000 (20:51 -0500)]
pseries/drmem: don't cache node id in drmem_lmb struct

At memory hot-remove time we can retrieve an LMB's nid from its
corresponding memory_block.  There is no need to store the nid
in multiple locations.

Note that lmb_to_memblock() uses find_memory_block() to get the
corresponding memory_block.  As find_memory_block() runs in sub-linear
time this approach is negligibly slower than what we do at present.

In exchange for this lookup at hot-remove time we no longer need to
call memory_add_physaddr_to_nid() during drmem_init() for each LMB.
On powerpc, memory_add_physaddr_to_nid() is a linear search, so this
spares us an O(n^2) initialization during boot.

On systems with many LMBs that initialization overhead is palpable and
disruptive.  For example, on a box with 249854 LMBs we're seeing
drmem_init() take upwards of 30 seconds to complete:

[   53.721639] drmem: initializing drmem v2
[   80.604346] watchdog: BUG: soft lockup - CPU#65 stuck for 23s! [swapper/0:1]
[   80.604377] Modules linked in:
[   80.604389] CPU: 65 PID: 1 Comm: swapper/0 Not tainted 5.6.0-rc2+ #4
[   80.604397] NIP:  c0000000000a4980 LR: c0000000000a4940 CTR: 0000000000000000
[   80.604407] REGS: c0002dbff8493830 TRAP: 0901   Not tainted  (5.6.0-rc2+)
[   80.604412] MSR:  8000000002009033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 44000248  XER: 0000000d
[   80.604431] CFAR: c0000000000a4a38 IRQMASK: 0
[   80.604431] GPR00: c0000000000a4940 c0002dbff8493ac0 c000000001904400 c0003cfffffede30
[   80.604431] GPR04: 0000000000000000 c000000000f4095a 000000000000002f 0000000010000000
[   80.604431] GPR08: c0000bf7ecdb7fb8 c0000bf7ecc2d3c8 0000000000000008 c00c0002fdfb2001
[   80.604431] GPR12: 0000000000000000 c00000001e8ec200
[   80.604477] NIP [c0000000000a4980] hot_add_scn_to_nid+0xa0/0x3e0
[   80.604486] LR [c0000000000a4940] hot_add_scn_to_nid+0x60/0x3e0
[   80.604492] Call Trace:
[   80.604498] [c0002dbff8493ac0] [c0000000000a4940] hot_add_scn_to_nid+0x60/0x3e0 (unreliable)
[   80.604509] [c0002dbff8493b20] [c000000000087c10] memory_add_physaddr_to_nid+0x20/0x60
[   80.604521] [c0002dbff8493b40] [c0000000010d4880] drmem_init+0x25c/0x2f0
[   80.604530] [c0002dbff8493c10] [c000000000010154] do_one_initcall+0x64/0x2c0
[   80.604540] [c0002dbff8493ce0] [c0000000010c4aa0] kernel_init_freeable+0x2d8/0x3a0
[   80.604550] [c0002dbff8493db0] [c000000000010824] kernel_init+0x2c/0x148
[   80.604560] [c0002dbff8493e20] [c00000000000b648] ret_from_kernel_thread+0x5c/0x74
[   80.604567] Instruction dump:
[   80.604574] 392918e8 e9490000 e90a000a e92a0000 80ea000c 1d080018 3908ffe8 7d094214
[   80.604586] 7fa94040 419d00dc e9490010 714a0088 <2faa0008409e00ac e9490000 7fbe5040
[   89.047390] drmem: 249854 LMB(s)

With a patched kernel on the same machine we're no longer seeing the
soft lockup.  drmem_init() now completes in negligible time, even when
the LMB count is large.

Fixes: b2d3b5ee66f2 ("powerpc/pseries: Track LMB nid instead of using device tree")
Signed-off-by: Scott Cheloha <cheloha@linux.ibm.com>
Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200811015115.63677-1-cheloha@linux.ibm.com
4 years agopowerpc: Rewrite FSL_BOOKE flush_cache_instruction() in C
Christophe Leroy [Fri, 14 Aug 2020 05:56:27 +0000 (05:56 +0000)]
powerpc: Rewrite FSL_BOOKE flush_cache_instruction() in C

Nothing prevents flush_cache_instruction() from being writen in C.

Do it to improve readability and maintainability.

This function is only use by low level callers, it is not
intended to be used by module. Don't export it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f989eff8296800c427622c0985384148404e4f0b.1597384512.git.christophe.leroy@csgroup.eu
4 years agopowerpc: Rewrite 4xx flush_cache_instruction() in C
Christophe Leroy [Fri, 14 Aug 2020 05:56:26 +0000 (05:56 +0000)]
powerpc: Rewrite 4xx flush_cache_instruction() in C

Nothing prevents flush_cache_instruction() from being writen in C.

Do it to improve readability and maintainability.

This function is very small and isn't called from assembly,
make it static inline in asm/cacheflush.h

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/93d93fc69b4b3ad3ceba2fc0756333c0c0245bb7.1597384512.git.christophe.leroy@csgroup.eu
4 years agopowerpc: Move flush_instruction_cache() prototype in asm/cacheflush.h
Christophe Leroy [Fri, 14 Aug 2020 05:56:25 +0000 (05:56 +0000)]
powerpc: Move flush_instruction_cache() prototype in asm/cacheflush.h

flush_instruction_cache() belongs to the cache flushing function
family.

Move its prototype in asm/cacheflush.h

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/993445b5227e8ca2f0e38bcc9ea3dfea6e865920.1597384512.git.christophe.leroy@csgroup.eu
4 years agopowerpc: Remove flush_instruction_cache for book3s/32
Christophe Leroy [Fri, 14 Aug 2020 05:56:24 +0000 (05:56 +0000)]
powerpc: Remove flush_instruction_cache for book3s/32

The only callers of flush_instruction_cache() are:

arch/powerpc/kernel/swsusp_booke.S: bl flush_instruction_cache
arch/powerpc/mm/nohash/40x.c: flush_instruction_cache();
arch/powerpc/mm/nohash/44x.c: flush_instruction_cache();
arch/powerpc/mm/nohash/fsl_booke.c: flush_instruction_cache();
arch/powerpc/platforms/44x/machine_check.c: flush_instruction_cache();
arch/powerpc/platforms/44x/machine_check.c: flush_instruction_cache();

This function is not used by book3s/32, drop it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/50098f49877cea0f46730a9df82dcabf84160e4b.1597384512.git.christophe.leroy@csgroup.eu
4 years agopowerpc/pseries: explicitly reschedule during drmem_lmb list traversal
Nathan Lynch [Thu, 13 Aug 2020 15:11:31 +0000 (10:11 -0500)]
powerpc/pseries: explicitly reschedule during drmem_lmb list traversal

The drmem lmb list can have hundreds of thousands of entries, and
unfortunately lookups take the form of linear searches. As long as
this is the case, traversals have the potential to monopolize the CPU
and provoke lockup reports, workqueue stalls, and the like unless
they explicitly yield.

Rather than placing cond_resched() calls within various
for_each_drmem_lmb() loop blocks in the code, put it in the iteration
expression of the loop macro itself so users can't omit it.

Introduce a drmem_lmb_next() iteration helper function which calls
cond_resched() at a regular interval during array traversal. Each
iteration of the loop in DLPAR code paths can involve around ten RTAS
calls which can each take up to 250us, so this ensures the check is
performed at worst every few milliseconds.

Fixes: 6c6ea53725b3 ("powerpc/mm: Separate ibm, dynamic-memory data from DT format")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200813151131.2070161-1-nathanl@linux.ibm.com