powerpc: Offline CPU in stop_this_cpu()

printk_safe_flush_on_panic() has special lock breaking code for the case
where we panic()ed with the console lock held. It relies on panic IPI
causing other CPUs to mark themselves offline.

Do as most other architectures do.

This effectively reverts commit de6e5d38417e ("powerpc: smp_send_stop do
not offline stopped CPUs"), unfortunately it may result in some false
positive warnings, but the alternative is more situations where we can
crash without getting messages out.

Fixes: de6e5d38417e ("powerpc: smp_send_stop do not offline stopped CPUs")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210623041245.865134-1-npiggin@gmail.com

powerpc: Make PPC_IRQ_SOFT_MASK_DEBUG depend on PPC64

32-bit platforms don't have irq soft masking.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210623032909.826010-1-npiggin@gmail.com

powerpc/64s: Remove irq mask workaround in accumulate_stolen_time()

The caller has been moved to C after irq soft-mask state has been
reconciled, and Linux IRQs have been marked as disabled, so this no
longer needs to play games with IRQ internals.

Fixes: 68b34588e202 ("powerpc/64/sycall: Implement syscall entry/exit logic in C")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210623022924.704645-1-npiggin@gmail.com

powerpc/pseries: Enable hardlockup watchdog for PowerVM partitions

PowerVM will not arbitrarily oversubscribe or stop guests, page out the
guest kernel text to a NFS volume connected by carrier pigeon to abacus
based storage, etc., as a KVM host might. So PowerVM guests are not
likely to be killed by the hard lockup watchdog in normal operation,
even with shared processor LPARs which still get a minimum allotment of
CPU time.

Enable the hard lockup detector by default on !KVM guests, which we will
assume is PowerVM. It has been useful in finding problems on bare metal
kernels.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210623021528.702241-1-npiggin@gmail.com

powerpc/64s/interrupt: Check and fix srr_valid without crashing

The PPC_RFI_SRR_DEBUG check added by patch "powerpc/64s: avoid reloading
(H)SRR registers if they are still valid" has a few deficiencies. It
does not fix the actual problem, it's not enabled by default, and it
causes a program check interrupt which can cause more difficulties.

However there are a lot of paths which may clobber SRRs or change return
regs, and difficult to have a high confidence that all paths are covered
without wider testing.

Add a relatively low overhead always-enabled check that catches most
such cases, reports once, and fixes it so the kernel can continue.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Rebase, use switch & INT names, squash in race fix from Nick]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/interrupt: Remove prep_irq_for_user_exit()

prep_irq_for_user_exit() has only one caller, squash it
inside that caller.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-18-npiggin@gmail.com

powerpc/interrupt: Refactor prep_irq_for_{user/kernel_enabled}_exit()

prep_irq_for_user_exit() is a superset of
prep_irq_for_kernel_enabled_exit().

Rename prep_irq_for_kernel_enabled_exit() as prep_irq_for_enabled_exit()
and have prep_irq_for_user_exit() use it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-17-npiggin@gmail.com

powerpc/interrupt: Interchange prep_irq_for_{kernel_enabled/user}_exit()

prep_irq_for_user_exit() is a superset of
prep_irq_for_kernel_enabled_exit(). In order to allow refactoring in
following patch, interchange the two. This will allow
prep_irq_for_user_exit() to call a renamed version of
prep_irq_for_kernel_enabled_exit().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-16-npiggin@gmail.com

powerpc/interrupt: Refactor interrupt_exit_user_prepare()

interrupt_exit_user_prepare() is a superset of
interrupt_exit_user_prepare_main().

Refactor to avoid code duplication.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-15-npiggin@gmail.com

powerpc/interrupt: Rename and lightly change syscall_exit_prepare_main()

Rename syscall_exit_prepare_main() into interrupt_exit_prepare_main()

Pass it the 'ret' so that it can 'or' it directly instead of
oring twice, once inside the function and once outside.

And remove 'r3' parameter which is not used.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[np: split out some changes into other patches]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-14-npiggin@gmail.com

powerpc/64: use interrupt restart table to speed up return from interrupt

Use the restart table facility to return from interrupt or system calls
without disabling MSR[EE] or MSR[RI].

Interrupt return asm is put into the low soft-masked region, to prevent
interrupts being processed here, although they are still taken as masked
interrupts which causes SRRs to be clobbered, and a pending soft-masked
interrupt to require replaying.

The return code uses restart table regions to redirct to a fixup handler
rather than continue with the exit, if such an interrupt happens. In
this case the interrupt return is redirected to a fixup handler which
reloads r1 for the interrupt stack and reloads registers and sets state
up to replay the soft-masked interrupt and try the exit again.

Some types of security exit fallback flushes and barriers are currently
unable to cope with reentrant interrupts, e.g., because they store some
state in the scratch SPR which would be clobbered even by masked
interrupts. For now the interrupts-enabled exits are disabled when these
flushes are used.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Guard unused exit_must_hard_disable() as reported by lkp]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-13-npiggin@gmail.com

powerpc/64: treat low kernel text as irqs soft-masked

Treat code below __end_soft_masked as soft-masked for the purpose
of alternate return. 64s already mostly does this for scv entry.

This will be used to exit from interrupts without disabling MSR[EE].

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-12-npiggin@gmail.com

powerpc/64: interrupt soft-enable race fix

Prevent interrupt restore from allowing racing hard interrupts going
ahead of previous soft-pending ones, by using the soft-masked restart
handler to allow a store to clear the soft-mask while knowing nothing
is soft-pending.

This probably doesn't matter much in practice, but it's a simple
demonstrator / test case to exercise the restart table logic.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-11-npiggin@gmail.com

powerpc/64: allow alternate return locations for soft-masked interrupts

The exception table fixup adjusts a failed page fault's interrupt return
location if it was taken at an address specified in the exception table,
to a corresponding fixup handler address.

Introduce a variation of that idea which adds a fixup table for NMIs and
soft-masked asynchronous interrupts. This will be used to protect
certain critical sections that are sensitive to being clobbered by
interrupts coming in (due to using the same SPRs and/or irq soft-mask
state).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-10-npiggin@gmail.com

powerpc/64s: save one more register in the masked interrupt handler

This frees up one more register (and takes advantage of that to
clean things up a little bit).

This register will be used in the following patch.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-9-npiggin@gmail.com

powerpc/64s: system call avoid setting MSR[RI] until we set MSR[EE]

This extends the MSR[RI]=0 window a little further into the system
call in order to pair RI and EE enabling with a single mtmsrd.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-8-npiggin@gmail.com

powerpc/64: move interrupt return asm to interrupt_64.S

The next patch would like to move interrupt return assembly code to a low
location before general text, so move it into its own file and include via
head_64.S

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-7-npiggin@gmail.com

powerpc/64s: avoid reloading (H)SRR registers if they are still valid

When an interrupt is taken, the SRR registers are set to return to where
it left off. Unless they are modified in the meantime, or the return
address or MSR are modified, there is no need to reload these registers
when returning from interrupt.

Introduce per-CPU flags that track the validity of SRR and HSRR
registers. These are cleared when returning from interrupt, when
using the registers for something else (e.g., OPAL calls), when
adjusting the return address or MSR of a context, and when context
switching (which changes the return address and MSR).

This improves the performance of interrupt returns.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fold in fixup patch from Nick]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-5-npiggin@gmail.com

powerpc/64s: introduce different functions to return from SRR vs HSRR interrupts

This makes no real difference yet except that HSRR type interrupts will
use hrfid to return. This is important for the next patch.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-4-npiggin@gmail.com

powerpc: remove interrupt exit helpers unused argument

The msr argument is not used, remove it.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-3-npiggin@gmail.com

powerpc/interrupt: Fix CONFIG ifdef typo

CONFIG_PPC_BOOK3S should be CONFIG_PPC_BOOK3S_64. restore_math is a
no-op for other configurations.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[np: split from another patch]
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-2-npiggin@gmail.com

powerpc/prom_init: Pass linux_banner to firmware via option vector 7

Pass the value of linux_banner to firmware via option vector 7.

Option vector 7 is described in "LoPAR" Linux on Power Architecture
Reference v2.9, in table B.7 on page 824:

  An ASCII character formatted null terminated string that describes
  the client operating system. The string shall be human readable and
  may be displayed on the console.

The string can be up to 256 bytes total, including the nul terminator.

linux_banner contains lots of information, and should make it possible
to identify the exact kernel version that is running:

  const char linux_banner[] =
  "Linux version " UTS_RELEASE " (" LINUX_COMPILE_BY "@"
  LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION "\n";

For example:
  Linux version 4.15.0-144-generic (buildd@bos02-ppc64el-018) (gcc
  version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)) #148-Ubuntu SMP Sat May 8
  02:32:13 UTC 2021 (Ubuntu 4.15.0-144.148-generic 4.15.18)

It's also printed at boot to the console/dmesg, which should make it
possible to correlate what firmware receives with the console/dmesg on
the machine.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621064938.2021419-2-mpe@ellerman.id.au

powerpc/prom_init: Convert prom_strcpy() into prom_strscpy_pad()

In a subsequent patch we'd like to have something like a strscpy_pad()
implementation usable in prom_init.c.

Currently we have a strcpy() implementation with only one caller, so
convert it into strscpy_pad() and update the caller.

Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621064938.2021419-1-mpe@ellerman.id.au

powerpc/64s: Fix boot failure with 4K Radix

When using the Radix MMU our PGD is always 64K, and must be naturally
aligned.

For a 4K page size kernel that means page alignment of swapper_pg_dir is
not sufficient, leading to failure to boot.

Use the existing MAX_PTRS_PER_PGD which has the correct value, and
avoids us hard-coding 64K here.

Fixes: e72421a085a8 ("powerpc: Define swapper_pg_dir[] in C")
Reported-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210624123420.2784187-1-mpe@ellerman.id.au

Merge branch 'topic/ppc-kvm' into next

Pull in some more ppc KVM patches we are keeping in our topic branch.

In particular this brings in the series to add H_RPT_INVALIDATE.

KVM: PPC: Book3S HV: Workaround high stack usage with clang

LLVM does not emit optimal byteswap assembly, which results in high
stack usage in kvmhv_enter_nested_guest() due to the inlining of
byteswap_pt_regs(). With LLVM 12.0.0:

arch/powerpc/kvm/book3s_hv_nested.c:289:6: error: stack frame size of
2512 bytes in function 'kvmhv_enter_nested_guest' [-Werror,-Wframe-larger-than=]
long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
     ^
1 error generated.

While this gets fixed in LLVM, mark byteswap_pt_regs() as
noinline_for_stack so that it does not get inlined and break the build
due to -Werror by default in arch/powerpc/. Not inlining saves
approximately 800 bytes with LLVM 12.0.0:

arch/powerpc/kvm/book3s_hv_nested.c:290:6: warning: stack frame size of
1728 bytes in function 'kvmhv_enter_nested_guest' [-Wframe-larger-than=]
long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
     ^
1 warning generated.

Cc: stable@vger.kernel.org # v4.20+
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://github.com/ClangBuiltLinux/linux/issues/1292
Link: https://bugs.llvm.org/show_bug.cgi?id=49610
Link: https://lore.kernel.org/r/202104031853.vDT0Qjqj-lkp@intel.com/
Link: https://gist.github.com/ba710e3703bf45043a31e2806c843ffd
Link: https://lore.kernel.org/r/20210621182440.990242-1-nathan@kernel.org

KVM: PPC: Book3S HV: Use H_RPT_INVALIDATE in nested KVM

In the nested KVM case, replace H_TLB_INVALIDATE by the new hcall
H_RPT_INVALIDATE if available. The availability of this hcall
is determined from "hcall-rpt-invalidate" string in ibm,hypertas-functions
DT property.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621085003.904767-7-bharata@linux.ibm.com

KVM: PPC: Book3S HV: Add KVM_CAP_PPC_RPT_INVALIDATE capability

Now that we have H_RPT_INVALIDATE fully implemented, enable
support for the same via KVM_CAP_PPC_RPT_INVALIDATE KVM capability

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621085003.904767-6-bharata@linux.ibm.com

KVM: PPC: Book3S HV: Nested support in H_RPT_INVALIDATE

Enable support for process-scoped invalidations from nested
guests and partition-scoped invalidations for nested guests.

Process-scoped invalidations for any level of nested guests
are handled by implementing H_RPT_INVALIDATE handler in the
nested guest exit path in L0.

Partition-scoped invalidation requests are forwarded to the
right nested guest, handled there and passed down to L0
for eventual handling.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
[aneesh: Nested guest partition-scoped invalidation changes]
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Squash in fixup patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621085003.904767-5-bharata@linux.ibm.com

KVM: PPC: Book3S HV: Add support for H_RPT_INVALIDATE

H_RPT_INVALIDATE does two types of TLB invalidations:

1. Process-scoped invalidations for guests when LPCR[GTSE]=0.
   This is currently not used in KVM as GTSE is not usually
   disabled in KVM.
2. Partition-scoped invalidations that an L1 hypervisor does on
   behalf of an L2 guest. This is currently handled
   by H_TLB_INVALIDATE hcall and this new replaces the old that.

This commit enables process-scoped invalidations for L1 guests.
Support for process-scoped and partition-scoped invalidations
from/for nested guests will be added separately.

Process scoped tlbie invalidations from L1 and nested guests
need RS register for TLBIE instruction to contain both PID and
LPID.  This patch introduces primitives that execute tlbie
instruction with both PID and LPID set in prepartion for
H_RPT_INVALIDATE hcall.

A description of H_RPT_INVALIDATE follows:

int64   /* H_Success: Return code on successful completion */
        /* H_Busy - repeat the call with the same */
        /* H_Parameter, H_P2, H_P3, H_P4, H_P5 : Invalid
   parameters */
hcall(const uint64 H_RPT_INVALIDATE, /* Invalidate RPT
translation
lookaside information */
      uint64 id,        /* PID/LPID to invalidate */
      uint64 target,    /* Invalidation target */
      uint64 type,      /* Type of lookaside information */
      uint64 pg_sizes,  /* Page sizes */
      uint64 start,     /* Start of Effective Address (EA)
   range (inclusive) */
      uint64 end)       /* End of EA range (exclusive) */

Invalidation targets (target)
-----------------------------
Core MMU        0x01 /* All virtual processors in the
partition */
Core local MMU  0x02 /* Current virtual processor */
Nest MMU        0x04 /* All nest/accelerator agents
in use by the partition */

A combination of the above can be specified,
except core and core local.

Type of translation to invalidate (type)
---------------------------------------
NESTED       0x0001  /* invalidate nested guest partition-scope */
TLB          0x0002  /* Invalidate TLB */
PWC          0x0004  /* Invalidate Page Walk Cache */
PRT          0x0008  /* Invalidate caching of Process Table
Entries if NESTED is clear */
PAT          0x0008  /* Invalidate caching of Partition Table
Entries if NESTED is set */

A combination of the above can be specified.

Page size mask (pages)
----------------------
4K              0x01
64K             0x02
2M              0x04
1G              0x08
All sizes       (-1UL)

A combination of the above can be specified.
All page sizes can be selected with -1.

Semantics: Invalidate radix tree lookaside information
           matching the parameters given.
* Return H_P2, H_P3 or H_P4 if target, type, or pageSizes parameters
  are different from the defined values.
* Return H_PARAMETER if NESTED is set and pid is not a valid nested
  LPID allocated to this partition
* Return H_P5 if (start, end) doesn't form a valid range. Start and
  end should be a valid Quadrant address and  end > start.
* Return H_NotSupported if the partition is not in running in radix
  translation mode.
* May invalidate more translation information than requested.
* If start = 0 and end = -1, set the range to cover all valid
  addresses. Else start and end should be aligned to 4kB (lower 11
  bits clear).
* If NESTED is clear, then invalidate process scoped lookaside
  information. Else pid specifies a nested LPID, and the invalidation
  is performed   on nested guest partition table and nested guest
  partition scope real addresses.
* If pid = 0 and NESTED is clear, then valid addresses are quadrant 3
  and quadrant 0 spaces, Else valid addresses are quadrant 0.
* Pages which are fully covered by the range are to be invalidated.
  Those which are partially covered are considered outside
  invalidation range, which allows a caller to optimally invalidate
  ranges that may   contain mixed page sizes.
* Return H_SUCCESS on success.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621085003.904767-4-bharata@linux.ibm.com

powerpc/book3s64/radix: Add H_RPT_INVALIDATE pgsize encodings to mmu_psize_def

Add a field to mmu_psize_def to store the page size encodings
of H_RPT_INVALIDATE hcall. Initialize this while scanning the radix
AP encodings. This will be used when invalidating with required
page size encoding in the hcall.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621085003.904767-3-bharata@linux.ibm.com

KVM: PPC: Book3S HV: Fix comments of H_RPT_INVALIDATE arguments

The type values H_RPTI_TYPE_PRT and H_RPTI_TYPE_PAT indicate
invalidating the caching of process and partition scoped entries
respectively.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621085003.904767-2-bharata@linux.ibm.com

powerpc/boot: Add a boot wrapper for Microwatt

This allows microwatt's kernel to be built with an embedded device tree.

Load to arch/powerpc/boot/dtbImage.microwatt to 0x500000:

 mw_debug -b fpga stop load arch/powerpc/boot/dtbImage.microwatt 500000 start

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/YMwX19wym3kQ7guu@thinks.paulus.ozlabs.org

powerpc/boot: Fixup device-tree on little endian

This fixes the core devtree.c functions and the ns16550 UART backend.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/YMwXrPT8nc4YUdJ9@thinks.paulus.ozlabs.org

powerpc/microwatt: Add microwatt_defconfig

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/YMwXfL8hOpReIiiP@thinks.paulus.ozlabs.org

powerpc/microwatt: Add support for hardware random number generator

Microwatt's hardware RNG is accessed using the DARN instruction.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/YMwXPHlV/ZleiQUY@thinks.paulus.ozlabs.org

powerpc/microwatt: Use standard 16550 UART for console

This adds support to the Microwatt platform to use the standard
16550-style UART which available in the standalone Microwatt FPGA.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/YMwXGCTzedpQje7r@thinks.paulus.ozlabs.org

powerpc/xics: Add a native ICS backend for microwatt

This is a simple native ICS backend that matches the layout of
the Microwatt implementation of ICS.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
[mpe: Add empty ics_native_init() to unbreak non-microwatt builds]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
fixup-ics
Link: https://lore.kernel.org/r/YMwW8cxrwB2W5EUN@thinks.paulus.ozlabs.org

powerpc/microwatt: Populate platform bus from device-tree

Just like any other embedded platform.

Add an empty soc node.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/YMwWx98+PMibZq/G@thinks.paulus.ozlabs.org

powerpc: Add Microwatt device tree

Microwatt currently runs with MSR[HV] = 0, hence the usable-privilege
properties don't have bit 2 (for HV support) set, and we need the
/chosen/ibm,architecture-vec-5 property.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/YMwWkPcXlGDSQ9Q3@thinks.paulus.ozlabs.org

powerpc: Add Microwatt platform

Microwatt is a FPGA-based implementation of the Power ISA.  It
currently only implements little-endian 64-bit mode, and does
not (yet) support SMP, VMX, VSX or transactional memory.  It has an
optional FPU, and an optional MMU (required for running Linux,
obviously) which implements a configurable radix tree but not
hypervisor mode or nested radix translation.

This adds a new machine type to support FPGA-based SoCs with a
Microwatt core.  CONFIG_MATH_EMULATION can be selected for Microwatt
SOCs which don't have the FPU.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/YMwWbZVREsVug9R0@thinks.paulus.ozlabs.org

powerpc/32: use set_memory_attr()

Use set_memory_attr() instead of the PPC32 specific change_page_attr()

change_page_attr() was checking that the address was not mapped by
blocks and was handling highmem, but that's unneeded because the
affected pages can't be in highmem and block mapping verification
is already done by the callers.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[ruscur: rebase on powerpc/merge with Christophe's new patches]
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210609013431.9805-10-jniethe5@gmail.com

powerpc/mm: implement set_memory_attr()

In addition to the set_memory_xx() functions which allows to change
the memory attributes of not (yet) used memory regions, implement a
set_memory_attr() function to:
- set the final memory protection after init on currently used
kernel regions.
- enable/disable kernel memory regions in the scope of DEBUG_PAGEALLOC.

Unlike the set_memory_xx() which can act in three step as the regions
are unused, this function must modify 'on the fly' as the kernel is
executing from them. At the moment only PPC32 will use it and changing
page attributes on the fly is not an issue.

Reported-by: kbuild test robot <lkp@intel.com>
[ruscur: cast "data" to unsigned long instead of int]
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210609013431.9805-9-jniethe5@gmail.com

powerpc: Set ARCH_HAS_STRICT_MODULE_RWX

To enable strict module RWX on powerpc, set:

    CONFIG_STRICT_MODULE_RWX=y

You should also have CONFIG_STRICT_KERNEL_RWX=y set to have any real
security benefit.

ARCH_HAS_STRICT_MODULE_RWX is set to require ARCH_HAS_STRICT_KERNEL_RWX.
This is due to a quirk in arch/Kconfig and arch/powerpc/Kconfig that
makes STRICT_MODULE_RWX *on by default* in configurations where
STRICT_KERNEL_RWX is *unavailable*.

Since this doesn't make much sense, and module RWX without kernel RWX
doesn't make much sense, having the same dependencies as kernel RWX
works around this problem.

Book3s/32 603 and 604 core processors are not able to write protect
kernel pages so do not set ARCH_HAS_STRICT_MODULE_RWX for Book3s/32.

[jpn: - predicate on !PPC_BOOK3S_604
      - make module_alloc() use PAGE_KERNEL protection]

Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210609013431.9805-8-jniethe5@gmail.com

powerpc/bpf: Write protect JIT code

Add the necessary call to bpf_jit_binary_lock_ro() to remove write and
add exec permissions to the JIT image after it has finished being
written.

Without CONFIG_STRICT_MODULE_RWX the image will be writable and
executable until the call to bpf_jit_binary_lock_ro().

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210609013431.9805-7-jniethe5@gmail.com

powerpc/bpf: Remove bpf_jit_free()

Commit 74451e66d516 ("bpf: make jited programs visible in traces") added
a default bpf_jit_free() implementation. Powerpc did not use the default
bpf_jit_free() as powerpc did not set the images read-only. The default
bpf_jit_free() called bpf_jit_binary_unlock_ro() is why it could not be
used for powerpc.

Commit d53d2f78cead ("bpf: Use vmalloc special flag") moved keeping
track of read-only memory to vmalloc. This included removing
bpf_jit_binary_unlock_ro(). Therefore there is no reason powerpc needs
its own bpf_jit_free(). Remove it.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210609013431.9805-6-jniethe5@gmail.com

powerpc/kprobes: Mark newly allocated probes as ROX

Add the arch specific insn page allocator for powerpc. This allocates
ROX pages if STRICT_KERNEL_RWX is enabled. These pages are only written
to with patch_instruction() which is able to write RO pages.

Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[jpn: Reword commit message, switch to __vmalloc_node_range()]
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210609013431.9805-5-jniethe5@gmail.com

powerpc/modules: Make module_alloc() Strict Module RWX aware

Make module_alloc() use PAGE_KERNEL protections instead of
PAGE_KERNEL_EXEX if Strict Module RWX is enabled.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210609013431.9805-4-jniethe5@gmail.com

powerpc/lib/code-patching: Set up Strict RWX patching earlier

setup_text_poke_area() is a late init call so it runs before
mark_rodata_ro() and after the init calls. This lets all the init code
patching simply write to their locations. In the future, kprobes is
going to allocate its instruction pages RO which means they will need
setup_text__poke_area() to have been already called for their code
patching. However, init_kprobes() (which allocates and patches some
instruction pages) is an early init call so it happens before
setup_text__poke_area().

start_kernel() calls poking_init() before any of the init calls. On
powerpc, poking_init() is currently a nop. setup_text_poke_area() relies
on kernel virtual memory, cpu hotplug and per_cpu_areas being setup.
setup_per_cpu_areas(), boot_cpu_hotplug_init() and mm_init() are called
before poking_init().

Turn setup_text_poke_area() into poking_init().

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Russell Currey <ruscur@russell.cc>
[mpe: Fold in missing prototype for poking_init() from lkp]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210609013431.9805-3-jniethe5@gmail.com

powerpc/mm: Implement set_memory() routines

The set_memory_{ro/rw/nx/x}() functions are required for
STRICT_MODULE_RWX, and are generally useful primitives to have.  This
implementation is designed to be generic across powerpc's many MMUs.
It's possible that this could be optimised to be faster for specific
MMUs.

This implementation does not handle cases where the caller is attempting
to change the mapping of the page it is executing from, or if another
CPU is concurrently using the page being altered.  These cases likely
shouldn't happen, but a more complex implementation with MMU-specific code
could safely handle them.

On hash, the linear mapping is not kept in the linux pagetable, so this
will not change the protection if used on that range. Currently these
functions are not used on the linear map so just WARN for now.

apply_to_existing_page_range() does not work on huge pages so for now
disallow changing the protection of huge pages.

[jpn: - Allow set memory functions to be used without Strict RWX
      - Hash: Disallow certain regions
      - Have change_page_attr() take function pointers to manipulate ptes
      - Radix: Add ptesync after set_pte_at()]

Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210609013431.9805-2-jniethe5@gmail.com

powerpc/pesries: Get STF barrier requirement from H_GET_CPU_CHARACTERISTICS

This allows the hypervisor / firmware to describe this workarounds to
the guest.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210503130243.891868-4-npiggin@gmail.com

powerpc/security: Add a security feature for STF barrier

Rather than tying this mitigation to RFI L1D flush requirement, add a
new bit for it.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210503130243.891868-3-npiggin@gmail.com

powerpc/pseries: Get entry and uaccess flush required bits from H_GET_CPU_CHARACTERISTICS

This allows the hypervisor / firmware to describe these workarounds to
the guest.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210503130243.891868-2-npiggin@gmail.com

powerpc/boot: add zImage.lds to targets

This prevents spurious rebuilds of the lds and then wrappers.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210611111104.1058991-1-npiggin@gmail.com

powerpc/powernv: Fix machine check reporting of async store errors

POWER9 and POWER10 asynchronous machine checks due to stores have their
cause reported in SRR1 but SRR1[42] is set, which in other cases
indicates DSISR cause.

Check for these cases and clear SRR1[42], so the cause matching uses
the i-side (SRR1) table.

Fixes: 7b9f71f974a1 ("powerpc/64s: POWER9 machine check handler")
Fixes: 201220bb0e8c ("powerpc/powernv: Machine check handler for POWER10")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210517140355.2325406-1-npiggin@gmail.com

KVM: PPC: Book3S HV: Fix TLB management on SMT8 POWER9 and POWER10 processors

The POWER9 vCPU TLB management code assumes all threads in a core share
a TLB, and that TLBIEL execued by one thread will invalidate TLBs for
all threads. This is not the case for SMT8 capable POWER9 and POWER10
(big core) processors, where the TLB is split between groups of threads.
This results in TLB multi-hits, random data corruption, etc.

Fix this by introducing cpu_first_tlb_thread_sibling etc., to determine
which siblings share TLBs, and use that in the guest TLB flushing code.

[npiggin@gmail.com: add changelog and comment]

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210602040441.3984352-1-npiggin@gmail.com

crypto/nx: Register and unregister VAS interface on PowerVM

The user space uses /dev/crypto/nx-gzip interface to setup VAS
windows, create paste mapping and close windows. This patch adds
changes to create/remove this interface with VAS register/unregister
functions on PowerVM platform.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/121ea1f4eb3004f3b8f4fe8abefaecc88b292efd.camel@linux.ibm.com

crypto/nx: Add sysfs interface to export NX capabilities

Export NX-GZIP capabilities to usrespace in sysfs
/sys/devices/vio/ibm,compression-v1/nx_gzip_caps directory.
These are queried by userspace accelerator libraries to set
minimum length heuristics and maximum limits on request sizes.

NX-GZIP capabilities:
min_compress_len  /*Recommended minimum compress length in bytes*/
min_decompress_len /*Recommended minimum decompress length in bytes*/
req_max_processed_len /* Maximum number of bytes processed in one
request */

NX will return RMA_Reject if the request buffer size is greater
than req_max_processed_len.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/510da86abbd904878d5f13d74aba72603c37d783.camel@linux.ibm.com

crypto/nx: Get NX capabilities for GZIP coprocessor type

The hypervisor provides different NX capabilities that it
supports. These capabilities such as recommended minimum
compression / decompression lengths and the maximum request
buffer size in bytes are used to define the user space NX
request.

NX will reject the request if the buffer size is more than
the maximum buffer size. Whereas compression / decompression
lengths are recommended values for better performance.

Changes to get NX overall capabilities which points to the
specific features that the hypervisor supports. Then retrieve
the capabilities for the specific feature (available only
for NXGZIP).

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f2b6a1fb8b6112595a73d81c67a35af4e7f5d0a3.camel@linux.ibm.com

crypto/nx: Rename nx-842-pseries file name to nx-common-pseries

Rename nx-842-pseries.c to nx-common-pseries.c to add code for new
GZIP compression type. The actual functionality is not changed in
this patch.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1fcf672209a14ea8944bd3e49c8a7381c8f450f8.camel@linux.ibm.com

powerpc/pseries/vas: Setup IRQ and fault handling

NX generates an interrupt when sees a fault on the user space
buffer and the hypervisor forwards that interrupt to OS. Then
the kernel handles the interrupt by issuing H_GET_NX_FAULT hcall
to retrieve the fault CRB information.

This patch also adds changes to setup and free IRQ per each
window and also handles the fault by updating the CSB.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b8fc66dcb783d06a099a303e5cfc69087bb3357a.camel@linux.ibm.com

powerpc/pseries/vas: Integrate API with open/close windows

This patch adds VAS window allocatioa/close with the corresponding
hcalls. Also changes to integrate with the existing user space VAS
API and provide register/unregister functions to NX pseries driver.

The driver register function is used to create the user space
interface (/dev/crypto/nx-gzip) and unregister to remove this entry.

The user space process opens this device node and makes an ioctl
to allocate VAS window. The close interface is used to deallocate
window.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e8d956bace3f182c4d2e66e343ff37cb0391d1fd.camel@linux.ibm.com

powerpc/pseries/vas: Implement getting capabilities from hypervisor

The hypervisor provides VAS capabilities for GZIP default and QoS
features. These capabilities gives information for the specific
features such as total number of credits available in LPAR,
maximum credits allowed per window, maximum credits allowed in
LPAR, whether usermode copy/paste is supported, and etc.

This patch adds the following:
- Retrieve all features that are provided by hypervisor using
  H_QUERY_VAS_CAPABILITIES hcall with 0 as feature type.
- Retrieve capabilities for the specific feature using the same
  hcall and the feature type (1 for QoS and 2 for default type).

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/177c88608cb88f7b87d1c546103f18cec6c056b4.camel@linux.ibm.com

powerpc/pseries/vas: Add hcall wrappers for VAS handling

This patch adds the following hcall wrapper functions to allocate,
modify and deallocate VAS windows, and retrieve VAS capabilities.

H_ALLOCATE_VAS_WINDOW: Allocate VAS window
H_DEALLOCATE_VAS_WINDOW: Close VAS window
H_MODIFY_VAS_WINDOW: Setup window before using
H_QUERY_VAS_CAPABILITIES: Get VAS capabilities

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/40fb02a4d56ca4e240b074a15029082055be5997.camel@linux.ibm.com

powerpc/vas: Define QoS credit flag to allocate window

PowerVM introduces two different type of credits: Default and Quality
of service (QoS).

The total number of default credits available on each LPAR depends
on CPU resources configured. But these credits can be shared or
over-committed across LPARs in shared mode which can result in
paste command failure (RMA_busy). To avoid NX HW contention, the
hypervisor ntroduces QoS credit type which makes sure guaranteed
access to NX esources. The system admins can assign QoS credits
or each LPAR via HMC.

Default credit type is used to allocate a VAS window by default as
on PowerVM implementation. But the process can pass
VAS_TX_WIN_FLAG_QOS_CREDIT flag with VAS_TX_WIN_OPEN ioctl to open
QoS type window.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/aa950b7b8e8077364267720274a7b9ec34e76e73.camel@linux.ibm.com

powerpc/pseries/vas: Define VAS/NXGZIP hcalls and structs

This patch adds hcalls and other definitions. Also define structs
that are used in VAS implementation on PowerVM.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b4b8c594c27ee4aa6be9dc6dc4ee7331571cbbe8.camel@linux.ibm.com

powerpc/vas: Define and use common vas_window struct

Many elements in vas_struct are used on PowerNV and PowerVM
platforms. vas_window is used for both TX and RX windows on
PowerNV and for TX windows on PowerVM. So some elements are
specific to these platforms.

So this patch defines common vas_window and platform
specific window structs (pnv_vas_window on PowerNV). Also adds
the corresponding changes in PowerNV vas code.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1698c35c158dfe52c6d2166667823d3d4a463353.camel@linux.ibm.com

powerpc/vas: Move update_csb/dump_crb to common book3s platform

If a coprocessor encounters an error translating an address, the
VAS will cause an interrupt in the host. The kernel processes
the fault by updating CSB. This functionality is same for both
powerNV and pseries. So this patch moves these functions to
common vas-api.c and the actual functionality is not changed.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/bf8d5b0770fa1ef5cba88c96580caa08d999d3b5.camel@linux.ibm.com

powerpc/vas: Create take/drop pid and mm reference functions

Take pid and mm references when each window opens and drops during
close. This functionality is needed for powerNV and pseries. So
this patch defines the existing code as functions in common book3s
platform vas-api.c

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2fa40df962250a737c804e58202924717b39e381.camel@linux.ibm.com

powerpc/vas: Add platform specific user window operations

PowerNV uses registers to open/close VAS windows, and getting the
paste address. Whereas the hypervisor calls are used on PowerVM.

This patch adds the platform specific user space window operations
and register with the common VAS user space interface.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f85091f4ace67f951ac04d60394d67b21e2f5d3c.camel@linux.ibm.com

powerpc/powernv/vas: Rename register/unregister functions

powerNV and pseries drivers register / unregister to the corresponding
platform specific VAS separately. Then these VAS functions call the
common API with the specific window operations. So rename powerNV VAS
API register/unregister functions.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/9db00d58dbdcb7cfc07a1df95f3d2a9e3e5d746a.camel@linux.ibm.com

powerpc/vas: Move VAS API to book3s common platform

The pseries platform will share vas and nx code and interfaces
with the PowerNV platform, so create the
arch/powerpc/platforms/book3s/ directory and move VAS API code
there. Functionality is not changed.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e05c8db17b9eabe3545b902d034238e4c6c08180.camel@linux.ibm.com

powerpc/powernv/vas: Release reference to tgid during window close

The kernel handles the NX fault by updating CSB or sending
signal to process. In multithread applications, children can
open VAS windows and can exit without closing them. But the
parent can continue to send NX requests with these windows. To
prevent pid reuse, reference will be taken on pid and tgid
when the window is opened and release them during window close.

The current code is not releasing the tgid reference which can
cause pid leak and this patch fixes the issue.

Fixes: db1c08a740635 ("powerpc/vas: Take reference to PID and mm for user space windows")
Cc: stable@vger.kernel.org # 5.8+
Reported-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/6020fc4d444864fe20f7dcdc5edfe53e67480a1c.camel@linux.ibm.com

Merge branch 'topic/ppc-kvm' into next

Merge some powerpc KVM patches from our topic branch.

In particular this brings in Nick's big series rewriting parts of the
guest entry/exit path in C.

Conflicts:
arch/powerpc/kernel/security.c
arch/powerpc/kvm/book3s_hv_rmhandlers.S

powerpc/mm/book3s64: Fix possible build error

Update _tlbiel_pid() such that we can avoid build errors like below when
using this function in other places.

arch/powerpc/mm/book3s64/radix_tlb.c: In function ‘__radix__flush_tlb_range_psize’:
arch/powerpc/mm/book3s64/radix_tlb.c:114:2: warning: ‘asm’ operand 3 probably does not match constraints
  114 |  asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
      |  ^~~
arch/powerpc/mm/book3s64/radix_tlb.c:114:2: error: impossible constraint in ‘asm’
make[4]: *** [scripts/Makefile.build:271: arch/powerpc/mm/book3s64/radix_tlb.o] Error 1
m

With this fix, we can also drop the __always_inline in __radix_flush_tlb_range_psize
which was added by commit e12d6d7d46a6 ("powerpc/mm/radix: mark __radix__flush_tlb_range_psize() as __always_inline")

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210610083639.387365-1-aneesh.kumar@linux.ibm.com

powerpc/signal64: Don't read sigaction arguments back from user memory

When delivering a signal to a sigaction style handler (SA_SIGINFO), we
pass pointers to the siginfo and ucontext via r4 and r5.

Currently we populate the values in those registers by reading the
pointers out of the sigframe in user memory, even though the values in
user memory were written by the kernel just prior:

  unsafe_put_user(&frame->info, &frame->pinfo, badframe_block);
  unsafe_put_user(&frame->uc, &frame->puc, badframe_block);
  ...
  if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
   err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
   err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);

ie. we write &frame->info into frame->pinfo, and then read frame->pinfo
back into r4, and similarly for &frame->uc.

The code has always been like this, since linux-fullhistory commit
d4f2d95eca2c ("Forward port of 2.4 ppc64 signal changes.").

There's no reason for us to read the values back from user memory,
rather than just setting the value in the gpr[4/5] directly. In fact
reading the value back from user memory opens up the possibility of
another user thread changing the values before we read them back.
Although any process doing that would be racing against the kernel
delivering the signal, and would risk corrupting the stack, so that
would be a userspace bug.

Note that this is 64-bit only code, so there's no subtlety with the size
of pointers differing between kernel and user. Also the frame variable
is not modified to point elsewhere during the function.

In the past reading the values back from user memory was not costly, but
now that we have KUAP on some CPUs it is, so we'd rather avoid it for
that reason too.

So change the code to just set the values directly, using the same
values we have written to the sigframe previously in the function.

Note also that this matches what our 32-bit signal code does.

Using a version of will-it-scale's signal1_threads that sets SA_SIGINFO,
this results in a ~4% increase in signals per second on a Power9, from
229,777 to 239,766.

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210610072949.3198522-1-mpe@ellerman.id.au

powerpc/watchdog: include linux/processor.h for spin_until_cond

This implementation uses spin_until_cond in wd_smp_lock including
neither linux/processor.h nor asm/processor.h

This patch includes linux/processor.h here for spin_until_cond usage.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.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/5e8d2d50f301a346040362028c2ecba40685de9e.1623438544.git.christophe.leroy@csgroup.eu

powerpc/64: drop redundant defination of spin_until_cond

linux/processor.h has exactly same defination for spin_until_cond.
Drop the redundant defination in asm/processor.h

Signed-off-by: Sudeep Holla <sudeep.holla@arm.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/1fff2054e5dfc00329804dbd3f2a91667c9a8aff.1623438544.git.christophe.leroy@csgroup.eu

powerpc/signal32: Remove impossible #ifdef combinations

PPC_TRANSACTIONAL_MEM is only on book3s/64
SPE is only on booke

PPC_TRANSACTIONAL_MEM selects ALTIVEC and VSX

Therefore, within PPC_TRANSACTIONAL_MEM sections,
ALTIVEC and VSX are always defined while SPE never is.

Remove all SPE code and all #ifdef ALTIVEC and VSX in tm
functions.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a069a348ee3c2fe3123a5a93695c2b35dc42cb40.1623340691.git.christophe.leroy@csgroup.eu

powerpc/32: Display modules range in virtual memory layout

book3s/32 and 8xx don't use vmalloc for modules.

Print the modules area at startup as part of the virtual memory layout:

[    0.000000] Kernel virtual memory layout:
[    0.000000]   * 0xffafc000..0xffffc000  : fixmap
[    0.000000]   * 0xc9000000..0xffafc000  : vmalloc & ioremap
[    0.000000]   * 0xb0000000..0xc0000000  : modules
[    0.000000] Memory: 118480K/131072K available (7152K kernel code, 2320K rwdata, 1328K rodata, 368K init, 854K bss, 12592K reserved, 0K cma-reserved)

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/98394503e92d6fd6d8f657e0b263b32f21cf2790.1623438478.git.christophe.leroy@csgroup.eu

powerpc: make stack walking KASAN-safe

Make our stack-walking code KASAN-safe by using __no_sanitize_address.
Generic code, arm64, s390 and x86 all make accesses unchecked for similar
sorts of reasons: when unwinding a stack, we might touch memory that KASAN
has marked as being out-of-bounds. In ppc64 KASAN development, I hit this
sometimes when checking for an exception frame - because we're checking
an arbitrary offset into the stack frame.

See commit 20955746320e ("s390/kasan: avoid false positives during stack
unwind"), commit bcaf669b4bdb ("arm64: disable kasan when accessing
frame->fp in unwind_frame"), commit 91e08ab0c851 ("x86/dumpstack:
Prevent KASAN false positive warnings") and commit 6e22c8366416
("tracing, kasan: Silence Kasan warning in check_stack of stack_tracer").

Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210614120907.1952321-1-dja@axtens.net

selftests/powerpc: EBB selftest for MMCR0 control for PMU SPRs in ISA v3.1

With the MMCR0 control bit (PMCCEXT) in ISA v3.1, read access to
group B registers is restricted when MMCR0 PMCC=0b00. In other
platforms (like power9), the older behaviour works where group B
PMU SPRs are readable.

Patch creates a selftest which verifies that the test takes a
SIGILL when attempting to read PMU registers via helper function
"dump_ebb_state" for ISA v3.1.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com <mailto:rnsastry@linux.ibm.com>>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1621950703-1532-3-git-send-email-atrajeev@linux.vnet.ibm.com

selftests/powerpc: Fix "no_handler" EBB selftest

The "no_handler_test" in ebb selftests attempts to read the PMU
registers twice via helper function "dump_ebb_state". First dump is
just before closing of event and the second invocation is done after
closing of the event. The original intention of second
dump_ebb_state was to dump the state of registers at the end of
the test when the counters are frozen. But this will be achieved
with the first call itself since sample period is set to low value
and PMU will be frozen by then. Hence patch removes the
dump which was done before closing of the event.

Reported-by: Shirisha Ganta <shirisha.ganta1@ibm.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com <mailto:rnsastry@linux.ibm.com>>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1621950703-1532-2-git-send-email-atrajeev@linux.vnet.ibm.com

powerpc: Move update_power8_hid0() into its only user

update_power8_hid0() is used only by powernv platform subcore.c

Move it there.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/37f41d74faa0c66f90b373e243e8b1ee37a1f6fa.1623219019.git.christophe.leroy@csgroup.eu

powerpc: Remove proc_trap()

proc_trap() has never been used, 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/827944ea12d470c2f862635f48b5ee6c1520351f.1623217909.git.christophe.leroy@csgroup.eu

powerpc/32: Remove __main()

Comment says that __main() is there to make GCC happy.

It's been there since the implementation of ppc arch in Linux 1.3.45.

ppc32 is the only architecture having that. Even ppc64 doesn't have it.

Seems like GCC is still happy without it.

Drop it for good.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d01028f8166b98584eec536b52f14c5e3f98ff6b.1623172922.git.christophe.leroy@csgroup.eu

powerpc/32s: Rename PTE_SIZE to PTE_T_SIZE

PTE_SIZE means PTE page table size in most placed, whereas
in hash_low.S in means size of one entry in the table.

Rename it PTE_T_SIZE, and define it directly in hash_low.S
instead of going through asm-offsets.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/83a008a9fd6cc3f2bbcb470f592555d260ed7a3d.1623063174.git.christophe.leroy@csgroup.eu

powerpc: Define swapper_pg_dir[] in C

Don't duplicate swapper_pg_dir[] in each platform's head.S

Define it in mm/pgtable.c

Define MAX_PTRS_PER_PGD because on book3s/64 PTRS_PER_PGD is
not a constant.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5e3f1b8a4695c33ccc80aa3870e016bef32b85e1.1623063174.git.christophe.leroy@csgroup.eu

powerpc: Define empty_zero_page[] in C

At the time being, empty_zero_page[] is defined in each
platform head.S.

Define it in mm/mem.c instead, and put it in BSS section instead
of the DATA section. Commit 5227cfa71f9e ("arm64: mm: place
empty_zero_page in bss") explains why it is interesting to have
it in BSS.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5838caffa269e0957c5a50cc85477876220298b0.1623063174.git.christophe.leroy@csgroup.eu

powerpc/selftests: Use gettid() instead of getppid() for null_syscall

gettid() is 10% lighter than getppid(), use it for null_syscall selftest.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0ad62673d3e063f848e7c99d719bb966efd433e8.1622809833.git.christophe.leroy@csgroup.eu

powerpc/nohash: Remove DEBUG_HARDER

DEBUG_HARDER is not user selectable.

Remove it together with related messages.

Also remove two pr_devel() messages that should
likely have been pr_hard().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0f25109b0e12fdd1e6541dedbb2212cc53526a57.1622712515.git.christophe.leroy@csgroup.eu

powerpc/nohash: Remove DEBUG_CLAMP_LAST_CONTEXT

DEBUG_CLAMP_LAST_CONTEXT was there in the old days to reduce
number of contexts in order to ease debugging implementation
of context switching, but that's been quite stable during
years now.

As it is not user selectable, 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/da81837b452e8b9f1657b529b9c3050dc10b9770.1622712515.git.christophe.leroy@csgroup.eu

powerpc/nohash: Remove DEBUG_MAP_CONSISTENCY

mmu_context handling has been there for years, so we
would know if there was problems with maps.

DEBUG_MAP_CONSISTENCY is not user selectable, 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/6fe2b88956db53f8d6ee221525b2c5dc6aec82c6.1622712515.git.christophe.leroy@csgroup.eu

powerpc/nohash: Remove CONFIG_SMP #ifdefery in mmu_context.h

Everything can be done even when CONFIG_SMP is not selected.

Just use IS_ENABLED() where relevant and rely on GCC to
opt out unneeded code and variables when CONFIG_SMP is not set.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/cc13b87b0f750a538621876ecc24c22a07e7c8be.1622712515.git.christophe.leroy@csgroup.eu

powerpc/nohash: Convert set_context() to C

ppc8xx already has set_context() in C.

Other ones have it in assembly. The only thing it does is to
write the context id into SPRN_PID.

Do it in C.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a5d0759064f3831c6b88af49ef5d3b05ba1c4dad.1622712515.git.christophe.leroy@csgroup.eu

powerpc/nohash: Refactor update of BDI2000 pointers in switch_mmu_context()

Instead of duplicating the update of BDI2000 pointers in
set_context(), do it directly from switch_mmu_context().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4c54997edd3548fa54717915e7c6ebaf60f208c0.1622712515.git.christophe.leroy@csgroup.eu

powerpc/kuap: Force inlining of all first level KUAP helpers.

All KUAP helpers defined in asm/kup.h are single line functions
that should be inlined. But on book3s/32 build, we get many
instances of <prevent_write_to_user.constprop.0>.

Force inlining of those helpers.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8479a862e165a57a855292d47e24c259a578f5a0.1622711627.git.christophe.leroy@csgroup.eu

powerpc/kuap: Remove to/from/size parameters of prevent_user_access()

prevent_user_access() doesn't use anymore to/from/size parameters.

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/b7113662fd2c26e4c33e9d705de324bd3860822e.1622708530.git.christophe.leroy@csgroup.eu

powerpc/kuap: Remove KUAP_CURRENT_XXX

book3s/32 was the only user of KUAP_CURRENT_XXX.

After rework of book3s/32 KUAP, it is 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/549214ecf6887d965645e664520d4886663c5ffb.1622708530.git.christophe.leroy@csgroup.eu

powerpc/32s: Activate KUAP and KUEP by default

Now that KUAP and KUEP have been significantly optimised and can be
disabled at boot time using 'nosmap' and 'nosmep' kernel parameters,
them can be active by default like in other powerpc platforms.

It is still possible to disable them completely in the configuration.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/86c7c74a3ba5312daea7e9658b096e2bcc6f4b64.1622708530.git.christophe.leroy@csgroup.eu