powerpc/64e: Tie PPC_BOOK3E_64 to PPC_E500MC

The only 64-bit Book3E CPUs we support require the selection
of CONFIG_PPC_E500MC.

However our Kconfig allows configurating a kernel that has 64-bit
Book3E support, but without CONFIG_PPC_E500MC enabled. Such a kernel
would never boot, it doesn't know about any CPUs.

To fix this, force CONFIG_PPC_E500MC to be selected whenever we are
building a 64-bit Book3E kernel.

And add a test to detect future situations where cpu_specs is empty.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ae5d8b8b3ccc346e61d2ec729767f92766273f0b.1663606875.git.christophe.leroy@csgroup.eu

powerpc/Kconfig: Fix non existing CONFIG_PPC_FSL_BOOKE

CONFIG_PPC_FSL_BOOKE doesn't exist. Should be CONFIG_FSL_BOOKE.

Fixes: 49e3d8ea6248 ("powerpc/fsl_booke: Enable STRICT_KERNEL_RWX")
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/828f6a64eeb51ce9abfa1d4e84c521a02fecebb8.1663606875.git.christophe.leroy@csgroup.eu

powerpc: dts: turris1x.dts: Fix labels in DSA cpu port nodes

DSA cpu port node has to be marked with "cpu" label.
So fix it for both cpu port nodes.

Fixes: 54c15ec3b738 ("powerpc: dts: Add DTS file for CZ.NIC Turris 1.x routers")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220827131538.14577-1-pali@kernel.org

powerpc: dts: turris1x.dts: Fix NOR partitions labels

Partition partition@20000 contains generic kernel image and it does not
have to be used only for rescue purposes. Partition partition@1c0000
contains bootable rescue system and partition partition@340000 contains
factory image/data for restoring to NAND. So change partition labels to
better fit their purpose by removing possible misleading substring "rootfs"
from these labels.

Fixes: 54c15ec3b738 ("powerpc: dts: Add DTS file for CZ.NIC Turris 1.x routers")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220830225500.8856-1-pali@kernel.org

powerpc: Always select HAVE_EFFICIENT_UNALIGNED_ACCESS

Currently powerpc selects HAVE_EFFICIENT_UNALIGNED_ACCESS in all cases
but one. The exception is if the kernel is being built little endian and
explicitly targeted for Power7.

The combination of Power7 and little endian was never commercially
supported, or widely used. It was only ever possible on bare metal
machines, using unofficial firmware, or in qemu guests hosted on those
machines.

The bare metal firmware support for Power7 was removed in 2019, see
skiboot commit 16b7ae64 ("Remove POWER7 and POWER7+ support").

Little endian kernel builds were switched to target Power8 or later in
2018, in commit a73657ea19ae ("powerpc/64: Add GENERIC_CPU support for
little endian"). Since then it's only been possible to boot a Power7/LE
kernel by explicitly building for Power7.

So drop the exception and always select HAVE_EFFICIENT_UNALIGNED_ACCESS.
If anyone does still have a Power7/LE machine it should hopefully
continue to boot, just with some performance penality, and if not they
can report a bug.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916131523.319123-1-mpe@ellerman.id.au

powerpc/highmem: Properly handle fragmented memory

In addition to checking whether a page is reserved before allocating
it to highmem, verify that it is valid memory.

Otherwise the kernel Oopses as below:

  mem auto-init: stack:off, heap alloc:off, heap free:off
  Kernel attempted to read user page (7df58) - exploit attempt? (uid: 0)
  BUG: Unable to handle kernel data access on read at 0x0007df58
  Faulting instruction address: 0xc01c8348
  Oops: Kernel access of bad area, sig: 11 [#1]
  BE PAGE_SIZE=4K SMP NR_CPUS=2 P2020RDB-PC
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper Not tainted 6.0.0-rc2-0caacb197b677410bdac81bc34f05235+ #121
  NIP:  c01c8348 LR: c01cb2bc CTR: 0000000a
  REGS: c10d7e20 TRAP: 0300   Not tainted  (6.0.0-rc2-0caacb197b677410bdac81bc34f05235+)
  MSR:  00021000 <CE,ME>  CR: 48044224  XER: 00000000
  DEAR: 0007df58 ESR: 00000000
  GPR00: c01cb294 c10d7f10 c1045340 00000001 00000004 c112bcc0 00000015 eedf1000
  GPR08: 00000003 0007df58 00000000 f0000000 28044228 00000200 00000000 00000000
  GPR16: 00000000 00000000 00000000 0275cb7a c0000000 00000001 0000075f 00000000
  GPR24: c1031004 00000000 00000000 00000001 c10f0000 eedf1000 00080000 00080000
  NIP free_unref_page_prepare.part.93+0x48/0x60
  LR  free_unref_page+0x84/0x4b8
  Call Trace:
    0xeedf1000 (unreliable)
    free_unref_page+0x5c/0x4b8
    mem_init+0xd0/0x194
    start_kernel+0x4c0/0x6d0
    set_ivor+0x13c/0x178

Reported-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Fixes: b0e0d68b1c52 ("powerpc/32: Allow fragmented physical memory")
Tested-by: Pali Rohár <pali@kernel.org>
[mpe: Trim oops]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f08cca5c46d67399c53262eca48e015dcf1841f9.1663695394.git.christophe.leroy@csgroup.eu

powerpc/prom_init: drop PROM_BUG()

Unused, let's drop it.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220920122302.99195-3-david@redhat.com

powerpc/mm: Make PAGE_KERNEL_xxx macros grep-friendly

Avoid multi-lines to help getting a complete view when using
grep. They still remain under the 100 chars limit.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/3bc3f5a51949ee7f52dba36677db23d4337c7995.1662544980.git.christophe.leroy@csgroup.eu

powerpc/mm: Reduce redundancy in pgtable.h

PAGE_KERNEL_TEXT, PAGE_KERNEL_EXEC and PAGE_AGP are the same
for all powerpcs.

Remove duplicated definitions.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/92254499430d13d99e4a4d7e9ad8e8284cb35380.1662544974.git.christophe.leroy@csgroup.eu

powerpc/book3s: Inline first level of update_mmu_cache()

update_mmu_cache() voids when hash page tables are not used.
On PPC32 that means when MMU_FTR_HPTE_TABLE is not defined.
On PPC64 that means when RADIX is enabled.

Rename core part of update_mmu_cache() as __update_mmu_cache()
and include the initial verification in an inlined caller.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/bea5ad0de7f83eff256116816d46c84fa0a444de.1662370698.git.christophe.leroy@csgroup.eu

powerpc: Rely on generic definition of hugepd_t and is_hugepd when unused

CONFIG_ARCH_HAS_HUGEPD is used to tell core mm when huge page
directories are used.

When they are not used, no need to provide hugepd_t or is_hugepd(),
just rely on the core mm fallback definition.

For that, change core mm behaviour so that CONFIG_ARCH_HAS_HUGEPD
is used instead of indirect is_hugepd macro existence.

powerpc being the only user of huge page directories, there is no
impact on other architectures.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/da81462d93069bb90fe5e762dd3283a644318937.1662543243.git.christophe.leroy@csgroup.eu

powerpc/nohash: Remove pgd_huge() stub

linux/hugetlb.h has a fallback pgd_huge() macro for when
pgd_huge is not defined.

Remove the powerpc redundant definitions.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ae6aa7fce84f7abcbf67f534271a4a6dd7949b0d.1662543243.git.christophe.leroy@csgroup.eu

powerpc/mm/64s: Drop p4d_leaf()

Because 64-bit Book3S uses pgtable-nop4d.h, the P4D is folded into the
PGD. So P4D entries are actually PGD entries, or vice versa.

The other way to think of it is that the P4D is a single entry page
table below the PGD. Zero bits of the address are needed to index into
the P4D, therefore a P4D entry maps the same size address space as a PGD
entry.

As explained in the previous commit, there are no huge page sizes
supported directly at the PGD level on 64-bit Book3S, so there are also
no huge page sizes supported at the P4D level.

Therefore p4d_is_leaf() can never be true, so drop the definition and
fallback to the default implementation that always returns false.

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/20220903123640.719846-2-mpe@ellerman.id.au

powerpc/mm/64s: Drop pgd_huge()

On powerpc there are two ways for huge pages to be represented in the
top level page table, aka PGD (Page Global Directory).

If the address space mapped by an individual PGD entry does not
correspond to a given huge page size, then the PGD entry points to a
non-standard page table, known as a "hugepd" (Huge Page Directory).
The hugepd contains some number of huge page PTEs sufficient to map the
address space with the given huge page size.

On the other hand, if the address space mapped by an individual PGD
entry does correspond exactly to a given huge page size, that PGD entry
is used to directly encode the huge page PTE in place. In this case the
pgd_huge() wrapper indicates to generic code that the PGD entry is
actually a huge page PTE.

This commit deals with the pgd_huge() case only, it does nothing with
respect to the hugepd case.

Over time the size of the virtual address space supported on powerpc has
increased several times, which means the location at which huge pages
can sit in the tree has also changed. There have also been new huge page
sizes added, with the introduction of the Radix MMU.

On Power9 and later with the Radix MMU, the largest huge page size in
any implementation is 1GB.

Since the introduction of Radix, 1GB entries have been supported at the
PUD level, with both 4K and 64K base page size. Radix has never had a
supported huge page size at the PGD level.

On Power8 or earlier, which uses the Hash MMU, or Power9 or later with
the Hash MMU enabled, the largest huge page size is 16GB.

Using the Hash MMU and a base page size of 4K, 16GB has never been a
supported huge page size at the PGD level, due to the geometry being
incompatible. The two supported huge page sizes (16M & 16GB) both use
the hugepd format.

Using the Hash MMU and a base page size of 64K, 16GB pages were
supported in the past at the PGD level.

However in commit ba95b5d03596 ("powerpc/mm/book3s/64: Rework page table
geometry for lower memory usage") the page table layout was reworked to
shrink the size of the PGD.

As a result the 16GB page size now fits at the PUD level when using 64K
base page size.

Therefore there are no longer any supported configurations where
pgd_huge() can be true, so drop the definitions for pgd_huge(), and
fallback to the generic definition which is always false.

Fixes: ba95b5d03596 ("powerpc/mm/book3s/64: Rework page table geometry for lower memory usage")
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/20220903123640.719846-1-mpe@ellerman.id.au

powerpc/microwatt: Remove unused early debug code

The original microwatt submission[1] included some early debug code for
using the Microwatt "potato" UART.

The series that was eventually merged switched to using a standard UART,
and so doesn't need any special early debug handling. But some of the
original code was merged accidentally under the non-existent
CONFIG_PPC_EARLY_DEBUG_MICROWATT.

Drop the unused code.

1: https://lore.kernel.org/linuxppc-dev/20200509050340.GD1464954@thinks.paulus.ozlabs.org/

Fixes: 48b545b8018d ("powerpc/microwatt: Use standard 16550 UART for console")
Reported-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220919052755.800907-1-mpe@ellerman.id.au

powerpc/64: Remove unused SYS_CALL_TABLE symbol

In interrupt_64.S, formerly entry_64.S, there are two toc entries
created for sys_call_table and compat_sys_call_table.

These are no longer used, since the system call entry was converted from
asm to C, so remove them.

Fixes: 68b34588e202 ("powerpc/64/sycall: Implement syscall entry/exit logic in C")
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220913124545.2817825-1-mpe@ellerman.id.au

powerpc/build: put sys_call_table in .data.rel.ro if RELOCATABLE

Const function pointers by convention live in .data.rel.ro if they need
to be relocated. Now that .data.rel.ro is linked into the read-only
region, put them in the right section. This doesn't make much practical
difference, but it will make the C conversion of sys_call_table a
smaller change as far as linking goes.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-8-npiggin@gmail.com

powerpc/64/build: merge .got and .toc input sections

Follow the binutils ld internal linker script and merge .got and .toc
input sections in the .got output section.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-7-npiggin@gmail.com

powerpc/64/build: only include .opd with ELFv1

ELFv2 does not use function descriptors so .opd is not required.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-6-npiggin@gmail.com

powerpc/build: move .data.rel.ro, .sdata2 to read-only

.sdata2 is a readonly small data section for ppc32, and .data.rel.ro
is data that needs relocating but is read-only after that so these
can both be moved to the read only memory region.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-5-npiggin@gmail.com

powerpc/build: move got, toc, plt, branch_lt sections to read-only

This moves linker-related tables from .data to read-only area.
Relocations are performed at early boot time before memory is protected,
after which there should be no modifications required.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Don't use SPECIAL as reported by lkp@intel.com]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-4-npiggin@gmail.com

powerpc/32/build: move got1/got2 sections out of text

Following the example from the binutils default linker script, move
.got1 and .got2 out of .text, to just after RO_DATA.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-3-npiggin@gmail.com

powerpc: move __end_rodata to cover arch read-only sections

powerpc has a number of read-only sections and tables that are put after
RO_DATA(). Move the __end_rodata symbol to cover these as well.

Setting memory to read-only at boot is done using __init_begin, change
that to use __end_rodata.

This makes is_kernel_rodata() exactly cover the read-only region, as
well as other things using __end_rodata (e.g., kernel/dma/debug.c).
Boot dmesg also prints the rodata size more accurately.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-2-npiggin@gmail.com

powerpc/vmlinux.lds: Add an explicit symbol for the SRWX boundary

Currently __init_begin is used as the boundary for strict RWX between
executable/read-only text and data, and non-executable (after boot) code
and data.

But that's a little subtle, so add an explicit symbol to document that
the SRWX boundary lies there, and add a comment making it clear that
__init_begin must also begin there.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916131422.318752-2-mpe@ellerman.id.au

powerpc/vmlinux.lds: Ensure STRICT_ALIGN_SIZE is at least page aligned

Add a check that STRICT_ALIGN_SIZE is aligned to at least PAGE_SIZE.

That then makes the alignment to PAGE_SIZE immediately after the
alignment to STRICT_ALIGN_SIZE redundant, so remove it.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916131422.318752-1-mpe@ellerman.id.au

powerpc/64: Remove unused prom_init_toc symbols

Commit 24d33ac5b8ff ("powerpc/64s: Make prom_init require RELOCATABLE")
made prom_init depend on CONFIG_RELOCATABLE.

But it missed cleaning up a case in the linker script for RELOCATABLE=n,
and associated symbols. Remove them now.

Fixes: 24d33ac5b8ff ("powerpc/64s: Make prom_init require RELOCATABLE")
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220920131157.1032707-1-mpe@ellerman.id.au

powerpc/pseries: move hcall_tracepoint_refcount out of .toc

The .toc section is not really intended for arbitrary data. Writable
data in particular prevents making the TOC read-only after relocation.
Move hcall_tracepoint_refcount into the .data section.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220926053823.2668799-1-npiggin@gmail.com

Merge branch 'fixes' into next

Merge our fixes branch to bring in a few things that new feature patches
rely on or conflict with.

KVM: PPC: remove orphan declarations from kvm_ppc.h

Remove the following orphan declarations from kvm_ppc.h:

1. kvmppc_mmu_priv_switch() has been removed since
commit dd9ebf1f9435 ("KVM: PPC: e500: Add shadow PID
support").
2. kvmppc_core_destroy_mmu() has been removed since
commit ecc0981ff07c ("KVM: ppc: cosmetic changes to mmu
hook names").
3. kvmppc_prepare_vrma() has been removed since
commit aa04b4cc5be6 ("KVM: PPC: Allocate RMAs (Real Mode
Areas) at boot for use by guests").

So remove the declarations for them from header file.

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220913075029.682327-10-cuigaosheng1@huawei.com

powerpc/ps3: remove orphan declarations from ps3av.h

Remove the following orphan declarations from ps3av.h:
1. ps3av_dev_open()
2. ps3av_dev_close()

They have been removed since commit 13a5e30cf740 ("[POWERPC] PS3:
Rework AV settings driver"), so remove them.

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Acked-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220913075029.682327-9-cuigaosheng1@huawei.com

powerpc/sysdev: remove unused xics_ipi_dispatch() declaration

xics_ipi_dispatch() has been removed since
commit 23d72bfd8f9f ("powerpc: Consolidate ipi message mux
and demux"), so remove it.

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220913075029.682327-8-cuigaosheng1@huawei.com

powerpc/powernv: remove orphan declarations from opal.h

Remove the following orphan declarations from opal.h:
1. opal_notifier_register()
2. opal_notifier_unregister()
3. opal_notifier_update_evt()
4. opal_notifier_enable()
5. opal_notifier_disable()

They have been removed since commit 81f2f7ce4c5b ("opal:
Remove events notifier"), so remove them.

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220913075029.682327-7-cuigaosheng1@huawei.com

powerpc/mm: remove orphan declarations from mmu_context.h

Remove the following orphan declarations from mmu_context.h:
1. switch_cop() and drop_cop() have been removed since
commit 6ff4d3e96652 ("powerpc: Remove old unused icswx
based coprocessor support").

2. mm_iommu_cleanup() has been removed since
commit 4b6fad7097f8 ("powerpc/mm/iommu, vfio/spapr: Put
pages on VFIO container shutdown").

So remove the declarations for them from header file.

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220913075029.682327-6-cuigaosheng1@huawei.com

powerpc: remove unused udbg_init_debug_beat() declaration

udbg_init_debug_beat() has been removed since
commit bf4981a00636 ("powerpc: Remove the celleb support"),
so remove it.

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220913075029.682327-5-cuigaosheng1@huawei.com

powerpc: remove unused chrp_event_scan() declaration

chrp_event_scan() has been removed since
commit 3d541c4b7f6e ("powerpc/chrp: Use the same RTAS
daemon as pSeries"), so remove it.

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220913075029.682327-4-cuigaosheng1@huawei.com

powerpc/spufs: remove orphan declarations from spufs.h

Remove the following orphan declarations from spufs.h:
1. spufs_coredump_calls has been removed since
commit 48cad41f7ee7 ("[POWERPC] spufs: Combine
spufs_coredump_calls with spufs_calls").

2. spufs_coredump_num_notes has been removed since
commit 936d5bf1d7dc ("[POWERPC] spufs: Get rid of spufs_coredump_num_notes,
it's not needed if we NULL terminate").

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220913075029.682327-3-cuigaosheng1@huawei.com

powerpc/xmon: remove unused ppc_parse_cpu() declaration

ppc_parse_cpu() has been removed since
commit 5b102782c7f4 ("powerpc/xmon: Enable disassembly
files (compilation changes)"), so remove it.

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220913075029.682327-2-cuigaosheng1@huawei.com

Revert "powerpc/rtas: Implement reentrant rtas call"

At the time this was submitted by Leonardo, I confirmed -- or thought
I had confirmed -- with PowerVM partition firmware development that
the following RTAS functions:

- ibm,get-xive
- ibm,int-off
- ibm,int-on
- ibm,set-xive

were safe to call on multiple CPUs simultaneously, not only with
respect to themselves as indicated by PAPR, but with arbitrary other
RTAS calls:

https://lore.kernel.org/linuxppc-dev/875zcy2v8o.fsf@linux.ibm.com/

Recent discussion with firmware development makes it clear that this
is not true, and that the code in commit b664db8e3f97 ("powerpc/rtas:
Implement reentrant rtas call") is unsafe, likely explaining several
strange bugs we've seen in internal testing involving DLPAR and
LPM. These scenarios use ibm,configure-connector, whose internal state
can be corrupted by the concurrent use of the "reentrant" functions,
leading to symptoms like endless busy statuses from RTAS.

Fixes: b664db8e3f97 ("powerpc/rtas: Implement reentrant rtas call")
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Laurent Dufour <laurent.dufour@fr.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220907220111.223267-1-nathanl@linux.ibm.com

powerpc/powernv: add missing of_node_put() in opal_export_attrs()

After using 'np' returned by of_find_node_by_path(), of_node_put()
need be called to decrease the refcount.

Fixes: 11fe909d2362 ("powerpc/powernv: Add OPAL exports attributes to sysfs")
Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220906141703.118192-1-zhengyongjun3@huawei.com

powerpc/85xx: Fix fall-through warning for Clang

Fix the following fallthrough warning:

arch/powerpc/platforms/85xx/mpc85xx_cds.c:161:3: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://github.com/KSPP/linux/issues/198
Link: https://lore.kernel.org/lkml/202209061224.KxORRGVg-lkp@intel.com/
Link: https://lore.kernel.org/r/Yxe8XTY5C9qJLd0Z@work

powerpc/64s: add pte_needs_flush and huge_pmd_needs_flush

Allow PTE changes to avoid flushing the TLB when access permissions are
being relaxed, the dirty bit is being set, and the accessed bit is being
changed.

Relaxing access permissions and setting dirty and accessed bits do not
require a flush because the MMU will re-load the PTE and notice the
updates (it may also cause a spurious fault).

Clearing the accessed bit does not require a flush because of the
imprecise PTE accessed bit accounting that is already performed, as
documented in ptep_clear_flush_young().

This reduces TLB flushing for some mprotect(2) calls.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/r/20220901110334.1618913-1-npiggin@gmail.com

powerpc/math-emu: Inhibit W=1 warnings

When building with W=1 you get:

arch/powerpc/math-emu/fre.c:6:5: error: no previous prototype for 'fre' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fsqrt.c:11:1: error: no previous prototype for 'fsqrt' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fsqrts.c:12:1: error: no previous prototype for 'fsqrts' [-Werror=missing-prototypes]
arch/powerpc/math-emu/frsqrtes.c:6:5: error: no previous prototype for 'frsqrtes' [-Werror=missing-prototypes]
arch/powerpc/math-emu/mtfsf.c:10:1: error: no previous prototype for 'mtfsf' [-Werror=missing-prototypes]
arch/powerpc/math-emu/mtfsfi.c:10:1: error: no previous prototype for 'mtfsfi' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fabs.c:7:1: error: no previous prototype for 'fabs' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fadd.c:11:1: error: no previous prototype for 'fadd' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fadds.c:12:1: error: no previous prototype for 'fadds' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fcmpo.c:11:1: error: no previous prototype for 'fcmpo' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fcmpu.c:11:1: error: no previous prototype for 'fcmpu' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fcmpu.c:14:19: error: variable 'B_c' set but not used [-Werror=unused-but-set-variable]
arch/powerpc/math-emu/fcmpu.c:13:19: error: variable 'A_c' set but not used [-Werror=unused-but-set-variable]
arch/powerpc/math-emu/fctiw.c:11:1: error: no previous prototype for 'fctiw' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fctiwz.c:11:1: error: no previous prototype for 'fctiwz' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fdiv.c:11:1: error: no previous prototype for 'fdiv' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fdivs.c:12:1: error: no previous prototype for 'fdivs' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fmadd.c:11:1: error: no previous prototype for 'fmadd' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fmadds.c:12:1: error: no previous prototype for 'fmadds' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fmsub.c:11:1: error: no previous prototype for 'fmsub' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fmsubs.c:12:1: error: no previous prototype for 'fmsubs' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fmul.c:11:1: error: no previous prototype for 'fmul' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fmuls.c:12:1: error: no previous prototype for 'fmuls' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fnabs.c:7:1: error: no previous prototype for 'fnabs' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fneg.c:7:1: error: no previous prototype for 'fneg' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fnmadd.c:11:1: error: no previous prototype for 'fnmadd' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fnmadds.c:12:1: error: no previous prototype for 'fnmadds' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fnmsub.c:11:1: error: no previous prototype for 'fnmsub' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fnmsubs.c:12:1: error: no previous prototype for 'fnmsubs' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fres.c:7:1: error: no previous prototype for 'fres' [-Werror=missing-prototypes]
arch/powerpc/math-emu/frsp.c:12:1: error: no previous prototype for 'frsp' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fsel.c:11:1: error: no previous prototype for 'fsel' [-Werror=missing-prototypes]
arch/powerpc/math-emu/lfs.c:12:1: error: no previous prototype for 'lfs' [-Werror=missing-prototypes]
arch/powerpc/math-emu/frsqrte.c:7:1: error: no previous prototype for 'frsqrte' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fsub.c:11:1: error: no previous prototype for 'fsub' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fsubs.c:12:1: error: no previous prototype for 'fsubs' [-Werror=missing-prototypes]
arch/powerpc/math-emu/mcrfs.c:10:1: error: no previous prototype for 'mcrfs' [-Werror=missing-prototypes]
arch/powerpc/math-emu/mffs.c:10:1: error: no previous prototype for 'mffs' [-Werror=missing-prototypes]
arch/powerpc/math-emu/mtfsb0.c:10:1: error: no previous prototype for 'mtfsb0' [-Werror=missing-prototypes]
arch/powerpc/math-emu/mtfsb1.c:10:1: error: no previous prototype for 'mtfsb1' [-Werror=missing-prototypes]
arch/powerpc/math-emu/stfiwx.c:7:1: error: no previous prototype for 'stfiwx' [-Werror=missing-prototypes]
arch/powerpc/math-emu/stfs.c:12:1: error: no previous prototype for 'stfs' [-Werror=missing-prototypes]
arch/powerpc/math-emu/fmr.c:7:1: error: no previous prototype for 'fmr' [-Werror=missing-prototypes]
arch/powerpc/math-emu/lfd.c:10:1: error: no previous prototype for 'lfd' [-Werror=missing-prototypes]
arch/powerpc/math-emu/stfd.c:7:1: error: no previous prototype for 'stfd' [-Werror=missing-prototypes]
arch/powerpc/math-emu/math_efp.c:177:5: error: no previous prototype for 'do_spe_mathemu' [-Werror=missing-prototypes]
arch/powerpc/math-emu/math_efp.c:726:5: error: no previous prototype for 'speround_handler' [-Werror=missing-prototypes]
arch/powerpc/math-emu/math_efp.c:893:12: error: no previous prototype for 'spe_mathemu_init' [-Werror=missing-prototypes]

Fix the warnings in math_efp.c by adding prototypes of do_spe_mathemu()
and speround_handler() to asm/processor.h and declare spe_mathemu_init()
static.

The other warnings are benign and not worth the churn of fixing them,
expecially the 'unused-but-set-variable' which would impact the core
part of 'math-emu'.

So silence them by adding -Wno-missing-prototypes -Wno-unused-but-set-variable.

But then you get:

arch/powerpc/math-emu/fre.c:6:5: error: no previous declaration for 'fre' [-Werror=missing-declarations]
arch/powerpc/math-emu/fsqrt.c:11:1: error: no previous declaration for 'fsqrt' [-Werror=missing-declarations]
arch/powerpc/math-emu/fsqrts.c:12:1: error: no previous declaration for 'fsqrts' [-Werror=missing-declarations]
arch/powerpc/math-emu/frsqrtes.c:6:5: error: no previous declaration for 'frsqrtes' [-Werror=missing-declarations]
arch/powerpc/math-emu/mtfsf.c:10:1: error: no previous declaration for 'mtfsf' [-Werror=missing-declarations]
arch/powerpc/math-emu/mtfsfi.c:10:1: error: no previous declaration for 'mtfsfi' [-Werror=missing-declarations]
arch/powerpc/math-emu/fabs.c:7:1: error: no previous declaration for 'fabs' [-Werror=missing-declarations]
arch/powerpc/math-emu/fadd.c:11:1: error: no previous declaration for 'fadd' [-Werror=missing-declarations]
arch/powerpc/math-emu/fadds.c:12:1: error: no previous declaration for 'fadds' [-Werror=missing-declarations]
arch/powerpc/math-emu/fcmpo.c:11:1: error: no previous declaration for 'fcmpo' [-Werror=missing-declarations]
arch/powerpc/math-emu/fcmpu.c:11:1: error: no previous declaration for 'fcmpu' [-Werror=missing-declarations]
arch/powerpc/math-emu/fctiw.c:11:1: error: no previous declaration for 'fctiw' [-Werror=missing-declarations]
arch/powerpc/math-emu/fctiwz.c:11:1: error: no previous declaration for 'fctiwz' [-Werror=missing-declarations]
arch/powerpc/math-emu/fdiv.c:11:1: error: no previous declaration for 'fdiv' [-Werror=missing-declarations]
arch/powerpc/math-emu/fdivs.c:12:1: error: no previous declaration for 'fdivs' [-Werror=missing-declarations]
arch/powerpc/math-emu/fmadd.c:11:1: error: no previous declaration for 'fmadd' [-Werror=missing-declarations]
arch/powerpc/math-emu/fmadds.c:12:1: error: no previous declaration for 'fmadds' [-Werror=missing-declarations]
arch/powerpc/math-emu/fmsub.c:11:1: error: no previous declaration for 'fmsub' [-Werror=missing-declarations]
arch/powerpc/math-emu/fmsubs.c:12:1: error: no previous declaration for 'fmsubs' [-Werror=missing-declarations]
arch/powerpc/math-emu/fmul.c:11:1: error: no previous declaration for 'fmul' [-Werror=missing-declarations]
arch/powerpc/math-emu/fmuls.c:12:1: error: no previous declaration for 'fmuls' [-Werror=missing-declarations]
arch/powerpc/math-emu/fnabs.c:7:1: error: no previous declaration for 'fnabs' [-Werror=missing-declarations]
arch/powerpc/math-emu/fneg.c:7:1: error: no previous declaration for 'fneg' [-Werror=missing-declarations]
arch/powerpc/math-emu/fnmadd.c:11:1: error: no previous declaration for 'fnmadd' [-Werror=missing-declarations]
arch/powerpc/math-emu/fnmadds.c:12:1: error: no previous declaration for 'fnmadds' [-Werror=missing-declarations]
arch/powerpc/math-emu/fnmsub.c:11:1: error: no previous declaration for 'fnmsub' [-Werror=missing-declarations]
arch/powerpc/math-emu/fnmsubs.c:12:1: error: no previous declaration for 'fnmsubs' [-Werror=missing-declarations]
arch/powerpc/math-emu/fres.c:7:1: error: no previous declaration for 'fres' [-Werror=missing-declarations]
arch/powerpc/math-emu/frsp.c:12:1: error: no previous declaration for 'frsp' [-Werror=missing-declarations]
arch/powerpc/math-emu/fsel.c:11:1: error: no previous declaration for 'fsel' [-Werror=missing-declarations]
arch/powerpc/math-emu/lfs.c:12:1: error: no previous declaration for 'lfs' [-Werror=missing-declarations]
arch/powerpc/math-emu/frsqrte.c:7:1: error: no previous declaration for 'frsqrte' [-Werror=missing-declarations]
arch/powerpc/math-emu/fsub.c:11:1: error: no previous declaration for 'fsub' [-Werror=missing-declarations]
arch/powerpc/math-emu/fsubs.c:12:1: error: no previous declaration for 'fsubs' [-Werror=missing-declarations]
arch/powerpc/math-emu/mcrfs.c:10:1: error: no previous declaration for 'mcrfs' [-Werror=missing-declarations]
arch/powerpc/math-emu/mffs.c:10:1: error: no previous declaration for 'mffs' [-Werror=missing-declarations]
arch/powerpc/math-emu/mtfsb0.c:10:1: error: no previous declaration for 'mtfsb0' [-Werror=missing-declarations]
arch/powerpc/math-emu/mtfsb1.c:10:1: error: no previous declaration for 'mtfsb1' [-Werror=missing-declarations]
arch/powerpc/math-emu/stfiwx.c:7:1: error: no previous declaration for 'stfiwx' [-Werror=missing-declarations]
arch/powerpc/math-emu/stfs.c:12:1: error: no previous declaration for 'stfs' [-Werror=missing-declarations]
arch/powerpc/math-emu/fmr.c:7:1: error: no previous declaration for 'fmr' [-Werror=missing-declarations]
arch/powerpc/math-emu/lfd.c:10:1: error: no previous declaration for 'lfd' [-Werror=missing-declarations]
arch/powerpc/math-emu/stfd.c:7:1: error: no previous declaration for 'stfd' [-Werror=missing-declarations]

So also add -Wno-missing-declarations.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/688084b40b5ac88f2905cb207d5dad947d8d34dc.1662531153.git.christophe.leroy@csgroup.eu

powerpc/pseries: Fix plpks crash on non-pseries

As reported[1] by Nathan, the recently added plpks driver will crash if
it's built into the kernel and booted on a non-pseries machine, eg
powernv:

  kernel BUG at arch/powerpc/kernel/syscall.c:39!
  Oops: Exception in kernel mode, sig: 5 [#1]
  LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV
  ...
  NIP system_call_exception+0x90/0x3d0
  LR  system_call_common+0xec/0x250
  Call Trace:
    0xc0000000035c3e10 (unreliable)
    system_call_common+0xec/0x250
  --- interrupt: c00 at plpar_hcall+0x38/0x60
  NIP:  c0000000000e4300 LR: c00000000202945c CTR: 0000000000000000
  REGS: c0000000035c3e80 TRAP: 0c00   Not tainted  (6.0.0-rc4)
  MSR:  9000000002009033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE>  CR: 28000284  XER: 00000000
  ...
  NIP plpar_hcall+0x38/0x60
  LR  pseries_plpks_init+0x64/0x23c
  --- interrupt: c00

On powernv Linux is the hypervisor, so a hypercall just ends up going to
the syscall path, which BUGs if the syscall (hypercall) didn't come from
userspace.

The fix is simply to not probe the plpks driver on non-pseries machines.

[1] https://lore.kernel.org/linuxppc-dev/Yxe06fbq18Wv9y3W@dev-arch.thelio-3990X/

Fixes: 2454a7af0f2a ("powerpc/pseries: define driver for Platform KeyStore")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Dan Horák <dan@danny.cz>
Reviewed-by: Dan Horák <dan@danny.cz>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20220907065038.1604504-1-mpe@ellerman.id.au

powerpc/pasemi: Use of_root in pas_pci_init()

Currently in pas_pci_init() a reference to the root node is leaked due
to a missing of_node_put(). Instead just use of_root directly.

Note that converting to of_find_compatible_node(NULL, ...) would
not be entirely equivalent, because that would check the compatible
property of the root node, whereas using of_root skips checking the root
node and start the search at the first child of the root.

Reported-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220906010313.1296714-1-mpe@ellerman.id.au

powerpc/pasemi: Use strscpy instead of strlcpy

find_i2c_driver() contained the last usage of strlcpy() in arch/powerpc.
The return value was used to check if strlen(src) >= n, for which
strscpy() returns -E2BIG.

Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220827063946.9073-1-ruscur@russell.cc

powerpc/xive: fix repeated words in comments

Delete the redundant word 'set'.

Signed-off-by: Jilin Yuan <yuanjilin@cdjrlc.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220831004706.35280-1-yuanjilin@cdjrlc.com

powerpc/vas: fix repeated words in comments

Delete the redundant word 'the'.

Signed-off-by: Jilin Yuan <yuanjilin@cdjrlc.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220831004914.37055-1-yuanjilin@cdjrlc.com

powerpc/mobility: fix repeated words in comments

Delete the redundant word 'the'.

Signed-off-by: Jilin Yuan <yuanjilin@cdjrlc.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220831005109.38314-1-yuanjilin@cdjrlc.com

powerpc/powermac/udbg_scc: Add missing of_node_put()s in udbg_scc_init()

During the iteration of for_each_child_of_node(), we need to call
of_node_put() for the old references stored in to 'ch_def' and 'ch_a'
as their refcounters have been increased in last iteration.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220716074344.540049-1-windhl@126.com

powerpc/powermac/pfunc_base: Add missing of_node_put() in macio_gpio_init_one()

Call of_node_put() for the reference 'gparent' escaped out of the
previous for_each_child_of_node() as it has increased the refcount.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220716073111.539739-1-windhl@126.com

powerpc/powermac/low_i2c: Add missing of_node_put() in kw_i2c_probe()

Call of_node_put() for the reference 'parent' returned by
of_get_parent() which has increased the refcount.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220716070758.539434-1-windhl@126.com

powerpc/powermac/feature: Add missing of_node_put()

In probe_one_macio(), call of_node_put() for the refernece 'node'
escaped out of the for_each_node_by_name() which has increased its
refcount. While the 'node' will finally escaped into a global reference,
we should still call of_node_put() in fail path which will stop global
reference creation.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220716065412.539153-1-windhl@126.com

powerpc/pci-common: Fix refcount bug for 'phb->dn'

In pcibios_alloc_controller(), 'phb' is allocated and escaped into
global 'hose_list'. So we should call of_node_get() when a new reference
created into 'phb->dn'. And when phb is freed, we should call
of_node_put() on it.

NOTE: This function is called in the iteration of for_each_xx in
chrp_find_bridges() and pSeries_discover_phbs(). If there is no
of_node_get(), the object may be prematurely freed.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220702022936.266146-1-windhl@126.com

powerpc/powernv: Add missing of_node_put()s

In these driver init functions, there are two kinds of errors:

(1) missing of_put_node() for of_find_compatible_node()'s returned
    pointer (refcount incremented)  in fail path or when it is not
    used anymore.
(2) missing of_put_node() for 'for_each_xxx' loop's break

Signed-off-by: Liang He <windhl@126.com>
[mpe: Use out_put_xxx goto label naming]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220620132553.4073863-1-windhl@126.com

powerpc/fsl_pci: Remove of_node_put() when reference escaped out

In fsl_pci_assign_primary(), we should remove the of_node_put()
when breaking out of the for_each_matching_node() as the 'np'
is escaped out by global 'fsl_pci_primary'.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220720124557.1256243-1-windhl@126.com

powerpc/85xx: Add missing of_node_get/put() in ge_imp3a_pci_assign_primary()

for_each_node_by_type() will automatically increase and decrease
the refcount during the iteration. However, there is a reference
escaped into global 'fsl_pci_primary' and we need to handle it.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220701140119.245435-1-windhl@126.com

powerpc/44x: Add of_node_put() when break out from for_each

In ppc47x_init_irq(), we need to call of_node_put() when there is
a break during the iteration of for_each_node_with_property() which
will automatically increase and decrease the refcount.

Signed-off-by: Liang He <windhl@126.com>
[mpe: mpic_alloc() takes its own reference]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220701133126.243102-1-windhl@126.com

powerpc/pci_dn: Add missing of_node_put()

In pci_add_device_node_info(), use of_node_put() to drop the reference
to 'parent' returned by of_get_parent() to keep refcount balance.

Fixes: cca87d303c85 ("powerpc/pci: Refactor pci_dn")
Co-authored-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/r/20220701131750.240170-1-windhl@126.com

powerpc/pseries: Add missing of_node_put()s in hotplug-cpu.c

In pseries_cpuhp_cache_use_count() and pseries_cpuhp_detach_nodes(),
we need carefully hold the reference returned by
of_find_next_cache_node() and use it to call of_node_put() to keep
refcount balance.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220621111701.4082889-1-windhl@126.com

macintosh: Add missing of_node_get() in do_attach()

We need a of_node_get() for of_find_compatible_node() to keep refcount
balance.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220622061652.4095330-1-windhl@126.com

powerpc/83xx: Add missing of_node_put() in mpc832x_spi_init()

In mpc832x_spi_init(), hold the reference returned by
of_find_compatible_node() and use it to call of_node_put() for refcount
balance.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220621080932.4081935-1-windhl@126.com

powerpc/512x: Add missing of_node_put() in clock-commonclk.c

In mpc5121_clk_provide_migration_support(), hold the reference returned
by of_find_compatible_node() and use it to call of_node_put() for refcount
balance.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220621080349.4081689-1-windhl@126.com

powerpc/powermac: Add missing of_node_put() in smp_core99_setup()

In smp_core99_setup(), add of_node_put() to drop the reference once it's
no longer needed.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220620150518.4074910-1-windhl@126.com

powerpc/sysdev/fsl_msi: Add missing of_node_put()

In fsl_setup_msi_irqs(), use of_node_put() to drop the reference
returned by of_parse_phandle().

Fixes: 895d603f945ba ("powerpc/fsl_msi: add support for the fsl, msi property in PCI nodes")
Co-authored-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220704145233.278539-1-windhl@126.com

powerpc/sysdev: Add missing of_node_put()s

Add of_node_put() in various paths to drop references once they are no
longer needed.

Signed-off-by: Liang He <windhl@126.com>
[mpe: Rewrite change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220620130221.4073228-1-windhl@126.com

powerpc/embedded6xx/ls_uart: Add missing of_node_put()

In ls_uarts_init(), add an of_node_put() to keep refcount balance.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220620065904.4071787-1-windhl@126.com

powerpc/pseries: Add missing of_node_put() in ibmebus

In ibmebus_match_path(), use of_node_put() to drop the reference
returned by of_find_node_by_path() before testing for equality of the
pointers.

Signed-off-by: Liang He <windhl@126.com>
[mpe: Rewrite change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220619074016.4068105-1-windhl@126.com

powerpc/cell: Add missing of_node_put() in iommu.c

In cell_iommu_init_disabled(), hold the reference returned by
of_find_node_by_name() and use it to call of_node_put() for reference
balance.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220701144949.252364-2-windhl@126.com

powerpc/cell: Add missing of_node_put()s in cbe_regs.c

There are several bugs as following:

(1) In cbe_get_be_node(), hold the reference returned by of_find_xxx and
    of_get_xxx OF APIs and use it to call of_node_put().
(2) In cbe_fill_regs_map(), same as above.
(3) In cbe_regs_init(), during the iteration of for_each_node_by_type(),
    the refcount of 'cpu' will be automatically increased and decreased.
    However, there is a reference escaped out into 'map->cpu_node' and
    it should be properly handled.

Signed-off-by: Liang He <windhl@126.com>
[mpe: Drop references before pointer equality test in cbe_get_be_node()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220701144949.252364-1-windhl@126.com

powerpc/cell: Add missing of_node_put()s

Use of_node_put() for of_find_node_by_path() and
of_find_node_by_phandle() to keep refcount balance.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220619072335.4067728-1-windhl@126.com

powerpc/kernel: Add missing of_node_put() in legacy_serial.c

In find_legacy_serial_ports(), of_find_node_by_path() will return a node
pointer with refcount incremented. The reference should be dropped with
of_node_put() when it is not used anymore.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220619070811.4067215-1-windhl@126.com

powerpc/perf: Add missing of_node_put()s in imc-pmu.c

In update_events_in_group(), of_find_node_by_phandle() will return
a node pointer with refcount incremented. The reference should be
dropped with of_node_put() in the failure path or when it is not used
anymore.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Link: https://lore.kernel.org/r/20220618071353.4059000-1-windhl@126.com

powerpc/embedded6xx: Add missing of_node_put()s

Add missing of_node_put()s in various paths.

Signed-off-by: Liang He <windhl@126.com>
[mpe: Rewrite change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220618041042.4058066-1-windhl@126.com

powerpc/8xx: Add missing of_node_put() in tqm8xx_setup.c

In init_ioports(), of_find_node_by_name() will return a node pointer
with refcount incremented. The reference should be dropped with
of_node_put() when it is not used anymore.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220618024930.4056825-1-windhl@126.com

powerpc/maple: Add missing of_node_put() in time.c

In maple_get_boot_time(), of_find_compatible_node() will return
a node pointer with refcount incremented. The reference should be
dropped with of_node_put() when it is not used anymore.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220617124045.4048757-1-windhl@126.com

powerpc/85xx: Add missing of_node_put() in sgy_cst1000

In gpio_halt_probe(), of_find_matching_node() will return a node
pointer with refcount incremented. The reference should be dropped with
of_node_put() in the failure path.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220617105011.4041123-1-windhl@126.com

powerpc/52xx: Add missing of_node_put() in media5200.c

In media5200_init_irq(), of_find_compatible_node() will return a
node pointer with refcount incremented. The reference should be dropped
with of_node_put() in the failure path or when it is not used anymore.

Don't worry about 'fpga_np == NULL' as of_node_put() can correctly
handle that.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220616144007.3987743-1-windhl@126.com

powerpc/85xx: Add missing of_node_put() in ksi8560.c

In ksi8560_setup_arch(), of_find_compatible_node() will return a
node pointer with refcount incremented. The reference should be dropped
with of_node_put() when it is not used anymore.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220616132922.3987053-1-windhl@126.com

powerpc/512x: Add missing of_node_put() in mpc5121_clk_init()

In mpc5121_clk_init(), of_find_compatible_node() will return a
node pointer with refcount incremented. The reference should be dropped
with of_node_put() when it is not used anymore.

Signed-off-by: Liang He <windhl@126.com>
[mpe: of_clk_add_provider() will take its own reference.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220615143703.3968898-1-windhl@126.com

powerpc/vdso: link with -z noexecstack

With recent binutils, the following warning appears:

  VDSO32L arch/powerpc/kernel/vdso/vdso32.so.dbg
/opt/gcc-12.2.0-nolibc/powerpc64-linux/bin/../lib/gcc/powerpc64-linux/12.2.0/../../../../powerpc64-linux/bin/ld: warning: arch/powerpc/kernel/vdso/getcpu-32.o: missing .note.GNU-stack section implies executable stack
/opt/gcc-12.2.0-nolibc/powerpc64-linux/bin/../lib/gcc/powerpc64-linux/12.2.0/../../../../powerpc64-linux/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker

To avoid that, explicitly tell the linker we don't want executable
stack.

For more explanations, see commit ffcf9c5700e4 ("x86: link vdso
and boot with -z noexecstack --no-warn-rwx-segments")

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b95f2e3216a574837dd61208444e9515c3423da4.1662132312.git.christophe.leroy@csgroup.eu

powerpc/math-emu: Remove -w build flag and fix warnings

As reported by Nathan, the module_init() macro was not taken into
account because the header was missing. That means spe_mathemu_init()
was never called.

This should have been detected by gcc at build time, but due to
'-w' flag it went undetected.

Removing that flag leads to many warnings hence errors.

Fix those warnings then remove the -w flag.

Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/2663961738a46073713786d4efeb53100ca156e7.1662134272.git.christophe.leroy@csgroup.eu

powerpc/math_emu/efp: Include module.h

When building with a recent version of clang, there are a couple of
errors around the call to module_init():

  arch/powerpc/math-emu/math_efp.c:927:1: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
  module_init(spe_mathemu_init);
  ^
  int
  arch/powerpc/math-emu/math_efp.c:927:13: error: a parameter list without types is only allowed in a function definition
  module_init(spe_mathemu_init);
              ^
  2 errors generated.

module_init() is a macro, which is not getting expanded because module.h
is not included in this file. Add the include so that the macro can
expand properly, clearing up the build failure.

Fixes: ac6f120369ff ("powerpc/85xx: Workaroudn e500 CPU erratum A005")
[chleroy: added fixes tag]
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/r/8403854a4c187459b2f4da3537f51227b70b9223.1662134272.git.christophe.leroy@csgroup.eu

powerpc/pseries: Move dtl scanning and steal time accounting to pseries platform

dtl is the PAPR Dispatch Trace Log, which is entirely a pseries feature.
The pseries platform alrady has a file dealing with the dtl, so move
scanning for stolen time accounting there from kernel/time.c.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220902085316.2071519-5-npiggin@gmail.com

powerpc/64: Remove PPC64 special case for cputime accounting default

Distro kernels tend to be moving to VIRT_CPU_ACCOUNTING_GEN, and there
is not much reason why PPC64 should be special here. Remove the special
case and make the ppc64 and pseries defconfigs use GEN accounting
(others will use TICK, as-per Kconfig defaults).

VIRT_CPU_ACCOUNTING_NATIVE does provide scaled vtime and stolen time
apportioned between system and user time, and vtime accounting is not
unconditionally enabled, and possibly other things. But it would be
better at this point to extend GEN to cover important missing features
rather than directing users back to a less used option.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220902085316.2071519-4-npiggin@gmail.com

powerpc/pseries: Implement CONFIG_PARAVIRT_TIME_ACCOUNTING

CONFIG_VIRT_CPU_ACCOUNTING_GEN under pseries does not provide stolen
time accounting unless CONFIG_PARAVIRT_TIME_ACCOUNTING is enabled.
Implement this using the VPA accumulated wait counters.

Note this will not work on current KVM hosts because KVM does not
implement the VPA dispatch counters (yet). It could be implemented
with the dispatch trace log as it is for VIRT_CPU_ACCOUNTING_NATIVE,
but that is not necessary for the more limited accounting provided
by PARAVIRT_TIME_ACCOUNTING, and it is more expensive, complex, and
has downsides like potential log wrap.

From Shrikanth:

  [...] it was tested on Power10 [PowerVM] Shared LPAR. system has two
  LPAR. we will call first one LPAR1 and second one as LPAR2. Test was
  carried out in SMT=1. Similar observation was seen in SMT=8 as well.

  LPAR config header from each LPAR is below. LPAR1 is twice as big as
  LPAR2. Since Both are sharing the same underlying hardware, work
  stealing will happen when both the LPAR's are contending for the same
  resource.

  LPAR1:
  type=Shared mode=Uncapped smt=Off lcpu=40 cpus=40 ent=20.00
  LPAR2:
  type=Shared mode=Uncapped smt=Off lcpu=20 cpus=40 ent=10.00

  mpstat was used to check for the utilization. stress-ng has been used
  as the workload. Few cases are tested. when the both LPAR are idle
  there is no steal time. when LPAR1 starts running at 100% which
  consumes all of the physical resource, steal time starts to get
  accounted.  With LPAR1 running at 100% and LPAR2 starts running, steal
  time starts increasing. This is as expected. When the LPAR2 Load is
  increased further, steal time increases further.

  Case 1: 0% LPAR1; 0% LPAR2
   %usr  %nice   %sys %iowait  %irq  %soft %steal %guest %gnice  %idle
   0.00   0.00   0.05   0.00   0.00   0.00   0.00   0.00   0.00  99.95

  Case 2: 100% LPAR1; 0% LPAR2
   %usr  %nice   %sys %iowait  %irq  %soft %steal %guest %gnice  %idle
  97.68   0.00   0.00   0.00   0.00   0.00   2.32   0.00   0.00   0.00

  Case 3: 100% LPAR1; 50% LPAR2
   %usr  %nice   %sys %iowait  %irq  %soft %steal %guest %gnice  %idle
  86.34   0.00   0.10   0.00   0.00   0.03  13.54   0.00   0.00   0.00

  Case 4: 100% LPAR1; 100% LPAR2
   %usr  %nice   %sys %iowait  %irq  %soft %steal %guest %gnice  %idle
  78.54   0.00   0.07   0.00   0.00   0.02  21.36   0.00   0.00   0.00

  Case 5: 50% LPAR1; 100% LPAR2
   %usr  %nice   %sys %iowait  %irq  %soft %steal %guest %gnice  %idle
  49.37   0.00   0.00   0.00   0.00   0.00   1.17   0.00   0.00  49.47

  Patch is accounting for the steal time and basic tests are holding
  good.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
[mpe: Add SPDX tag to new paravirt_api_clock.h]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220902085316.2071519-3-npiggin@gmail.com

powerpc/pseries: Add wait interval counter definitions to struct lppaca

The hypervisor exposes accumulated partition scheduling interval times
in the VPA (lppaca). These can be used to implement a simple stolen time
in the guest without complex and costly dtl scanning.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Link: https://lore.kernel.org/r/20220902085316.2071519-2-npiggin@gmail.com

selftests/powerpc: Skip 4PB test on 4K PAGE_SIZE systems

Systems using the hash MMU with a 4K page size don't support 4PB address
space, so skip the test because the bug it tests for can't be triggered.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220901020215.254097-1-mpe@ellerman.id.au

powerpc/configs: Properly enable PAPR_SCM in pseries_defconfig

My commit to add PAPR_SCM to pseries_defconfig failed to add the
required dependencies, meaning the driver doesn't get built.

Add the required LIBNVDIMM=m.

Fixes: d6481a7195df ("powerpc/configs: Add PAPR_SCM to pseries_defconfig")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220901014253.252927-1-mpe@ellerman.id.au

powerpc/papr_scm: Ensure rc is always initialized in papr_scm_pmu_register()

Clang warns:

  arch/powerpc/platforms/pseries/papr_scm.c:492:6: warning: variable 'rc' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
          if (!p->stat_buffer_len)
              ^~~~~~~~~~~~~~~~~~~
  arch/powerpc/platforms/pseries/papr_scm.c:523:64: note: uninitialized use occurs here
          dev_info(&p->pdev->dev, "nvdimm pmu didn't register rc=%d\n", rc);
                                                                        ^~
  include/linux/dev_printk.h:150:67: note: expanded from macro 'dev_info'
          dev_printk_index_wrap(_dev_info, KERN_INFO, dev, dev_fmt(fmt), ##__VA_ARGS__)
                                                                          ^~~~~~~~~~~
  include/linux/dev_printk.h:110:23: note: expanded from macro 'dev_printk_index_wrap'
                  _p_func(dev, fmt, ##__VA_ARGS__);                       \
                                      ^~~~~~~~~~~
  arch/powerpc/platforms/pseries/papr_scm.c:492:2: note: remove the 'if' if its condition is always false
          if (!p->stat_buffer_len)
          ^~~~~~~~~~~~~~~~~~~~~~~~
  arch/powerpc/platforms/pseries/papr_scm.c:484:8: note: initialize the variable 'rc' to silence this warning
          int rc, nodeid;
                ^
                = 0
  1 warning generated.

The call to papr_scm_pmu_check_events() was eliminated but a return code
was not added to the if statement. Add the same return code from
papr_scm_pmu_check_events() for this condition so there is no more
warning.

Fixes: 9b1ac04698a4 ("powerpc/papr_scm: Fix nvdimm event mappings")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://github.com/ClangBuiltLinux/linux/issues/1701
Link: https://lore.kernel.org/r/20220830151256.1473169-1-nathan@kernel.org

Revert "powerpc/irq: Don't open code irq_soft_mask helpers"

This reverts commit ef5b570d3700fbb8628a58da0487486ceeb713cd.

Zhouyi reported that commit is causing crashes when running rcutorture
with KASAN enabled:

  BUG: using smp_processor_id() in preemptible [00000000] code: rcu_torture_rea/100
  caller is rcu_preempt_deferred_qs_irqrestore+0x74/0xed0
  CPU: 4 PID: 100 Comm: rcu_torture_rea Tainted: G        W          5.19.0-rc5-next-20220708-dirty #253
  Call Trace:
    dump_stack_lvl+0xbc/0x108 (unreliable)
    check_preemption_disabled+0x154/0x160
    rcu_preempt_deferred_qs_irqrestore+0x74/0xed0
    __rcu_read_unlock+0x290/0x3b0
    rcu_torture_read_unlock+0x30/0xb0
    rcutorture_one_extend+0x198/0x810
    rcu_torture_one_read+0x58c/0xc90
    rcu_torture_reader+0x12c/0x360
    kthread+0x1e8/0x220
    ret_from_kernel_thread+0x5c/0x64

KASAN will generate instrumentation instructions around the
WRITE_ONCE(local_paca->irq_soft_mask, mask):

   0xc000000000295cb0 <+0>: addis   r2,r12,774
   0xc000000000295cb4 <+4>: addi    r2,r2,16464
   0xc000000000295cb8 <+8>: mflr    r0
   0xc000000000295cbc <+12>: bl      0xc00000000008bb4c <mcount>
   0xc000000000295cc0 <+16>: mflr    r0
   0xc000000000295cc4 <+20>: std     r31,-8(r1)
   0xc000000000295cc8 <+24>: addi    r3,r13,2354
   0xc000000000295ccc <+28>: mr      r31,r13
   0xc000000000295cd0 <+32>: std     r0,16(r1)
   0xc000000000295cd4 <+36>: stdu    r1,-48(r1)
   0xc000000000295cd8 <+40>: bl      0xc000000000609b98 <__asan_store1+8>
   0xc000000000295cdc <+44>: nop
   0xc000000000295ce0 <+48>: li      r9,1
   0xc000000000295ce4 <+52>: stb     r9,2354(r31)
   0xc000000000295ce8 <+56>: addi    r1,r1,48
   0xc000000000295cec <+60>: ld      r0,16(r1)
   0xc000000000295cf0 <+64>: ld      r31,-8(r1)
   0xc000000000295cf4 <+68>: mtlr    r0

If there is a context switch before "stb     r9,2354(r31)", r31 may
not equal to r13, in such case, irq soft mask will not work.

The usual solution of marking the code ineligible for instrumentation
forces the code out-of-line, which we would prefer to avoid. Christophe
proposed a partial revert, but Nick raised some concerns with that. So
for now do a full revert.

Reported-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
[mpe: Construct change log based on Zhouyi's original report]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220831131052.42250-1-mpe@ellerman.id.au

powerpc/32: Remove wii_memory_fixups()

wii_memory_fixups() is not called anymore, remove it.

Also remove left-overs in mmu_decl.h which were forgotten by
commit 160985f3025b ("powerpc/wii: remove wii_mmu_mapin_mem2()")

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5f2091f86528b59ef92ef1daed5d3dd8c0d7bebd.1661938317.git.christophe.leroy@csgroup.eu

powerpc/32: Allow fragmented physical memory

Since commit 9e849f231c3c ("powerpc/mm/32s: use generic mmu_mapin_ram()
for all blocks.") it is possible to map all blocks as RAM on any PPC32.

Remove related restrictions.

And remove call to wii_memory_fixups() which doesn't do anything else
than checks since commit 160985f3025b ("powerpc/wii: remove
wii_mmu_mapin_mem2()")

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/fc9a5b8ef49f6eb86e970d4c7ccfba9b407fd4eb.1661938317.git.christophe.leroy@csgroup.eu

powerpc/32: Drop a stale comment about reservation of gigantic pages

A comment about the reservation of gigantic pages was left in MMU_init()
after commit 79cc38ded1e1 ("powerpc/mm/hugetlb: Add support for
reserving gigantic huge pages via kernel command line")

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/959d77be630b9b46a7458f0fbd41dc3a94ec811a.1661938317.git.christophe.leroy@csgroup.eu

powerpc/code-patching: Speed up page mapping/unmapping

Since commit 591b4b268435 ("powerpc/code-patching: Pre-map patch area")
the patch area is premapped so intermediate page tables are already
allocated.

Use __set_pte_at() directly instead of the heavy map_kernel_page(),
at for unmapping just do a pte_clear() followed by a flush.

__set_pte_at() can be used directly without the filters in
set_pte_at() because we are mapping a normal page non executable.

Make sure gcc knows text_poke_area is page aligned in order to
optimise the flush.

This change reduces by 66% the time needed to activate ftrace on
an 8xx (588000 tb ticks instead of 1744000).

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Add ptesync needed on radix to avoid spurious fault]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220815114840.1468656-1-mpe@ellerman.id.au

powerpc: Fix hard_irq_disable() with sanitizer

As reported by Zhouyi Zhou, WRITE_ONCE() is not atomic
as expected when KASAN or KCSAN are compiled in.

Fix it by re-implementing it using inline assembly.

Fixes: 077fc62b2b66 ("powerpc/irq: remove inline assembly in hard_irq_disable macro")
Reported-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a8298991b3df049a54ee8e558838e34265812014.1661272586.git.christophe.leroy@csgroup.eu

powerpc/82xx: remove spidev node from mgcoge

Commit 956b200a846e ("spi: spidev: Warn loudly if instantiated from DT
as "spidev"") states that there should not be spidev nodes in DTs.
Remove this non-HW description. There won't be a regression because it
won't bind since 2015 anyhow.

Fixes: 5d1d67e361ea ("powerpc/82xx: add SPI support for mgcoge")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220824082130.21934-3-wsa+renesas@sang-engineering.com

powerpc/microwatt: Add LiteX MMC driver

Enable the LiteX MMC device and it's dependency the common clock
framework.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220804015708.5928-1-joel@jms.id.au

selftests/powerpc: Add a test for execute-only memory

This selftest is designed to cover execute-only protections
on the Radix MMU but will also work with Hash.

The tests are based on those found in pkey_exec_test with modifications
to use the generic mprotect() instead of the pkey variants.

Signed-off-by: Nicholas Miehlbradt <nicholas@linux.ibm.com>
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220817050640.406017-2-ruscur@russell.cc

powerpc/mm: Support execute-only memory on the Radix MMU

Add support for execute-only memory (XOM) for the Radix MMU by using an
execute-only mapping, as opposed to the RX mapping used by powerpc's
other MMUs.

The Hash MMU already supports XOM through the execute-only pkey,
which is a separate mechanism shared with x86.  A PROT_EXEC-only mapping
will map to RX, and then the pkey will be applied on top of it.

mmap() and mprotect() consumers in userspace should observe the same
behaviour on Hash and Radix despite the differences in implementation.

Replacing the vma_is_accessible() check in access_error() with a read
check should be functionally equivalent for non-Radix MMUs, since it
follows write and execute checks.  For Radix, the change enables
detecting faults on execute-only mappings where vma_is_accessible() would
return true.

Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220817050640.406017-1-ruscur@russell.cc

macintosh: move from strlcpy with unused retval to strscpy

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Link: https://lore.kernel.org/r/20220818210026.6940-1-wsa+renesas@sang-engineering.com