Commit Graph

104 Commits

Author SHA1 Message Date
Nicholas Piggin
8dc7f0229b powerpc: remove partial register save logic
All subarchitectures always save all GPRs to pt_regs interrupt frames
now. Remove FULL_REGS and associated bits.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210316104206.407354-11-npiggin@gmail.com
2021-04-14 23:04:44 +10:00
Christophe Leroy
5747230645 powerpc/32: Remove ksp_limit
ksp_limit is there to help detect stack overflows.
That is specific to ppc32 as it was removed from ppc64 in
commit cbc9565ee8 ("powerpc: Remove ksp_limit on ppc64").

There are other means for detecting stack overflows.

As ppc64 has proven to not need it, ppc32 should be able to do
without it too.

Lets remove it and simplify exception handling.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d789c3385b22e07bedc997613c0d26074cb513e7.1615552866.git.christophe.leroy@csgroup.eu
2021-03-29 13:22:05 +11:00
Jordan Niethe
5c88a17e15 powerpc/sstep: Fix VSX instruction emulation
Commit af99da7433 ("powerpc/sstep: Support VSX vector paired storage
access instructions") added loading and storing 32 word long data into
adjacent VSRs. However the calculation used to determine if two VSRs
needed to be loaded/stored inadvertently prevented the load/storing
taking place for instructions with a data length less than 16 words.

This causes the emulation to not function correctly, which can be seen
by the alignment_handler selftest:

$ ./alignment_handler
[snip]
test: test_alignment_handler_vsx_207
tags: git_version:powerpc-5.12-1-0-g82d2c16b350f
VSX: 2.07B
        Doing lxsspx:   PASSED
        Doing lxsiwax:  FAILED: Wrong Data
        Doing lxsiwzx:  PASSED
        Doing stxsspx:  PASSED
        Doing stxsiwx:  PASSED
failure: test_alignment_handler_vsx_207
test: test_alignment_handler_vsx_300
tags: git_version:powerpc-5.12-1-0-g82d2c16b350f
VSX: 3.00B
        Doing lxsd:     PASSED
        Doing lxsibzx:  PASSED
        Doing lxsihzx:  PASSED
        Doing lxssp:    FAILED: Wrong Data
        Doing lxv:      PASSED
        Doing lxvb16x:  PASSED
        Doing lxvh8x:   PASSED
        Doing lxvx:     PASSED
        Doing lxvwsx:   FAILED: Wrong Data
        Doing lxvl:     PASSED
        Doing lxvll:    PASSED
        Doing stxsd:    PASSED
        Doing stxsibx:  PASSED
        Doing stxsihx:  PASSED
        Doing stxssp:   PASSED
        Doing stxv:     PASSED
        Doing stxvb16x: PASSED
        Doing stxvh8x:  PASSED
        Doing stxvx:    PASSED
        Doing stxvl:    PASSED
        Doing stxvll:   PASSED
failure: test_alignment_handler_vsx_300
[snip]

Fix this by making sure all VSX instruction emulation correctly
load/store from the VSRs.

Fixes: af99da7433 ("powerpc/sstep: Support VSX vector paired storage access instructions")
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210225031946.1458206-1-jniethe5@gmail.com
2021-03-02 22:41:51 +11:00
Linus Torvalds
b12b472496 powerpc updates for 5.12
A large series adding wrappers for our interrupt handlers, so that irq/nmi/user
 tracking can be isolated in the wrappers rather than spread in each handler.
 
 Conversion of the 32-bit syscall handling into C.
 
 A series from Nick to streamline our TLB flushing when using the Radix MMU.
 
 Switch to using queued spinlocks by default for 64-bit server CPUs.
 
 A rework of our PCI probing so that it happens later in boot, when more generic
 infrastructure is available.
 
 Two small fixes to allow 32-bit little-endian processes to run on 64-bit
 kernels.
 
 Other smaller features, fixes & cleanups.
 
 Thanks to:
   Alexey Kardashevskiy, Ananth N Mavinakayanahalli, Aneesh Kumar K.V, Athira
   Rajeev, Bhaskar Chowdhury, Cédric Le Goater, Chengyang Fan, Christophe Leroy,
   Christopher M. Riedl, Fabiano Rosas, Florian Fainelli, Frederic Barrat, Ganesh
   Goudar, Hari Bathini, Jiapeng Chong, Joseph J Allen, Kajol Jain, Markus
   Elfring, Michal Suchanek, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver
   O'Halloran, Pingfan Liu, Po-Hsu Lin, Qian Cai, Ram Pai, Randy Dunlap, Sandipan
   Das, Stephen Rothwell, Tyrel Datwyler, Will Springer, Yury Norov, Zheng
   Yongjun.
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Merge tag 'powerpc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - A large series adding wrappers for our interrupt handlers, so that
   irq/nmi/user tracking can be isolated in the wrappers rather than
   spread in each handler.

 - Conversion of the 32-bit syscall handling into C.

 - A series from Nick to streamline our TLB flushing when using the
   Radix MMU.

 - Switch to using queued spinlocks by default for 64-bit server CPUs.

 - A rework of our PCI probing so that it happens later in boot, when
   more generic infrastructure is available.

 - Two small fixes to allow 32-bit little-endian processes to run on
   64-bit kernels.

 - Other smaller features, fixes & cleanups.

Thanks to: Alexey Kardashevskiy, Ananth N Mavinakayanahalli, Aneesh
Kumar K.V, Athira Rajeev, Bhaskar Chowdhury, Cédric Le Goater, Chengyang
Fan, Christophe Leroy, Christopher M. Riedl, Fabiano Rosas, Florian
Fainelli, Frederic Barrat, Ganesh Goudar, Hari Bathini, Jiapeng Chong,
Joseph J Allen, Kajol Jain, Markus Elfring, Michal Suchanek, Nathan
Lynch, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Pingfan Liu,
Po-Hsu Lin, Qian Cai, Ram Pai, Randy Dunlap, Sandipan Das, Stephen
Rothwell, Tyrel Datwyler, Will Springer, Yury Norov, and Zheng Yongjun.

* tag 'powerpc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (188 commits)
  powerpc/perf: Adds support for programming of Thresholding in P10
  powerpc/pci: Remove unimplemented prototypes
  powerpc/uaccess: Merge raw_copy_to_user_allowed() into raw_copy_to_user()
  powerpc/uaccess: Merge __put_user_size_allowed() into __put_user_size()
  powerpc/uaccess: get rid of small constant size cases in raw_copy_{to,from}_user()
  powerpc/64: Fix stack trace not displaying final frame
  powerpc/time: Remove get_tbl()
  powerpc/time: Avoid using get_tbl()
  spi: mpc52xx: Avoid using get_tbl()
  powerpc/syscall: Avoid storing 'current' in another pointer
  powerpc/32: Handle bookE debugging in C in syscall entry/exit
  powerpc/syscall: Do not check unsupported scv vector on PPC32
  powerpc/32: Remove the counter in global_dbcr0
  powerpc/32: Remove verification of MSR_PR on syscall in the ASM entry
  powerpc/syscall: implement system call entry/exit logic in C for PPC32
  powerpc/32: Always save non volatile GPRs at syscall entry
  powerpc/syscall: Change condition to check MSR_RI
  powerpc/syscall: Save r3 in regs->orig_r3
  powerpc/syscall: Use is_compat_task()
  powerpc/syscall: Make interrupt.c buildable on PPC32
  ...
2021-02-22 14:34:00 -08:00
Sandipan Das
22b89ba178 powerpc/sstep: Fix darn emulation
Commit 8813ff4960 ("powerpc/sstep: Check instruction validity
against ISA version before emulation") introduced a proper way to skip
unknown instructions. This makes sure that the same is used for the
darn instruction when the range selection bits have a reserved value.

Fixes: a23987ef26 ("powerpc: sstep: Add support for darn instruction")
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210204080744.135785-2-sandipan@linux.ibm.com
2021-02-09 01:10:08 +11:00
Sandipan Das
bbda4b6c7d powerpc/sstep: Fix load-store and update emulation
The Power ISA says that the fixed-point load and update instructions
must neither use R0 for the base address (RA) nor have the
destination (RT) and the base address (RA) as the same register.
Similarly, for fixed-point stores and floating-point loads and stores,
the instruction is invalid when R0 is used as the base address (RA).

This is applicable to the following instructions.
  * Load Byte and Zero with Update (lbzu)
  * Load Byte and Zero with Update Indexed (lbzux)
  * Load Halfword and Zero with Update (lhzu)
  * Load Halfword and Zero with Update Indexed (lhzux)
  * Load Halfword Algebraic with Update (lhau)
  * Load Halfword Algebraic with Update Indexed (lhaux)
  * Load Word and Zero with Update (lwzu)
  * Load Word and Zero with Update Indexed (lwzux)
  * Load Word Algebraic with Update Indexed (lwaux)
  * Load Doubleword with Update (ldu)
  * Load Doubleword with Update Indexed (ldux)
  * Load Floating Single with Update (lfsu)
  * Load Floating Single with Update Indexed (lfsux)
  * Load Floating Double with Update (lfdu)
  * Load Floating Double with Update Indexed (lfdux)
  * Store Byte with Update (stbu)
  * Store Byte with Update Indexed (stbux)
  * Store Halfword with Update (sthu)
  * Store Halfword with Update Indexed (sthux)
  * Store Word with Update (stwu)
  * Store Word with Update Indexed (stwux)
  * Store Doubleword with Update (stdu)
  * Store Doubleword with Update Indexed (stdux)
  * Store Floating Single with Update (stfsu)
  * Store Floating Single with Update Indexed (stfsux)
  * Store Floating Double with Update (stfdu)
  * Store Floating Double with Update Indexed (stfdux)

E.g. the following behaviour is observed for an invalid load and
update instruction having RA = RT.

While a userspace program having an instruction word like 0xe9ce0001,
i.e. ldu r14, 0(r14), runs without getting receiving a SIGILL on a
Power system (observed on P8 and P9), the outcome of executing that
instruction word varies and its behaviour can be considered to be
undefined.

Attaching an uprobe at that instruction's address results in emulation
which currently performs the load as well as writes the effective
address back to the base register. This might not match the outcome
from hardware.

To remove any inconsistencies, this adds additional checks for the
aforementioned instructions to make sure that the emulation
infrastructure treats them as unknown. The kernel can then fallback to
executing such instructions on hardware.

Fixes: 0016a4cf55 ("powerpc: Emulate most Book I instructions in emulate_step()")
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210204080744.135785-1-sandipan@linux.ibm.com
2021-02-09 01:09:48 +11:00
Ravi Bangoria
344717a14c powerpc/sstep: Fix array out of bound warning
Compiling kernel with -Warray-bounds throws below warning:

  In function 'emulate_vsx_store':
  warning: array subscript is above array bounds [-Warray-bounds]
  buf.d[2] = byterev_8(reg->d[1]);
  ~~~~~^~~
  buf.d[3] = byterev_8(reg->d[0]);
  ~~~~~^~~

Fix it by using temporary array variable 'union vsx_reg buf32[]' in
that code block. Also, with element_size = 32, 'union vsx_reg *reg'
is an array of size 2. So, use 'reg' as an array instead of pointer
in the same code block.

Fixes: af99da7433 ("powerpc/sstep: Support VSX vector paired storage access instructions")
Suggested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210129071745.111466-1-ravi.bangoria@linux.ibm.com
2021-01-30 22:23:26 +11:00
Ananth N Mavinakayanahalli
718aae916f powerpc/sstep: Fix incorrect return from analyze_instr()
We currently just percolate the return value from analyze_instr()
to the caller of emulate_step(), especially if it is a -1.

For one particular case (opcode = 4) for instructions that aren't
currently emulated, we are returning 'should not be single-stepped'
while we should have returned 0 which says 'did not emulate, may
have to single-step'.

Fixes: 930d6288a2 ("powerpc: sstep: Add support for maddhd, maddhdu, maddld instructions")
Signed-off-by: Ananth N Mavinakayanahalli <ananth@linux.ibm.com>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/161157999039.64773.14950289716779364766.stgit@thinktux.local
2021-01-30 11:40:04 +11:00
Ananth N Mavinakayanahalli
8813ff4960 powerpc/sstep: Check instruction validity against ISA version before emulation
We currently unconditionally try to emulate newer instructions on older
Power versions that could cause issues. Gate it.

Fixes: 350779a29f ("powerpc: Handle most loads and stores in instruction emulation code")
Signed-off-by: Ananth N Mavinakayanahalli <ananth@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/161157995977.64773.13794501093457185080.stgit@thinktux.local
2021-01-30 11:39:34 +11:00
Balamuruhan S
af99da7433 powerpc/sstep: Support VSX vector paired storage access instructions
VSX Vector Paired instructions loads/stores an octword (32 bytes)
from/to storage into two sequential VSRs. Add emulation support
for these new instructions:
  * Load VSX Vector Paired (lxvp)
  * Load VSX Vector Paired Indexed (lxvpx)
  * Prefixed Load VSX Vector Paired (plxvp)
  * Store VSX Vector Paired (stxvp)
  * Store VSX Vector Paired Indexed (stxvpx)
  * Prefixed Store VSX Vector Paired (pstxvp)

[kernel test robot reported a build failure]

Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Balamuruhan S <bala24@linux.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201011050908.72173-4-ravi.bangoria@linux.ibm.com
2020-12-11 00:09:09 +11:00
Ravi Bangoria
1817de2f14 powerpc/sstep: Cover new VSX instructions under CONFIG_VSX
Recently added Power10 prefixed VSX instruction are included
unconditionally in the kernel. If they are executed on a
machine without VSX support, it might create issues. Fix that.
Also fix one mnemonics spelling mistake in comment.

Fixes: 50b80a12e4 ("powerpc sstep: Add support for prefixed load/stores")
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201011050908.72173-3-ravi.bangoria@linux.ibm.com
2020-12-11 00:09:09 +11:00
Balamuruhan S
ef6879f8c8 powerpc/sstep: Emulate prefixed instructions only when CPU_FTR_ARCH_31 is set
Unconditional emulation of prefixed instructions will allow
emulation of them on Power10 predecessors which might cause
issues. Restrict that.

Fixes: 3920742b92 ("powerpc sstep: Add support for prefixed fixed-point arithmetic")
Fixes: 50b80a12e4 ("powerpc sstep: Add support for prefixed load/stores")
Signed-off-by: Balamuruhan S <bala24@linux.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Sandipan Das <sandipan@linux.ibm.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201011050908.72173-2-ravi.bangoria@linux.ibm.com
2020-12-11 00:09:09 +11:00
Linus Torvalds
f56e65dff6 Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull initial set_fs() removal from Al Viro:
 "Christoph's set_fs base series + fixups"

* 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: Allow a NULL pos pointer to __kernel_read
  fs: Allow a NULL pos pointer to __kernel_write
  powerpc: remove address space overrides using set_fs()
  powerpc: use non-set_fs based maccess routines
  x86: remove address space overrides using set_fs()
  x86: make TASK_SIZE_MAX usable from assembly code
  x86: move PAGE_OFFSET, TASK_SIZE & friends to page_{32,64}_types.h
  lkdtm: remove set_fs-based tests
  test_bitmap: remove user bitmap tests
  uaccess: add infrastructure for kernel builds with set_fs()
  fs: don't allow splice read/write without explicit ops
  fs: don't allow kernel reads and writes without iter ops
  sysctl: Convert to iter interfaces
  proc: add a read_iter method to proc proc_ops
  proc: cleanup the compat vs no compat file ops
  proc: remove a level of indentation in proc_get_inode
2020-10-22 09:59:21 -07:00
Cédric Le Goater
5ab187e01a powerpc/sstep: Remove empty if statement checking for invalid form
The check should be performed by the caller. This fixes a compile
error with W=1.

../arch/powerpc/lib/sstep.c: In function ‘mlsd_8lsd_ea’:
../arch/powerpc/lib/sstep.c:225:3: error: suggest braces around empty body in an ‘if’ statement [-Werror=empty-body]
   ; /* Invalid form. Should already be checked for by caller! */
   ^

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200914211007.2285999-4-clg@kaod.org
2020-09-18 20:05:24 +10:00
Christoph Hellwig
5ae4998b5d powerpc: remove address space overrides using set_fs()
Stop providing the possibility to override the address space using
set_fs() now that there is no need for that any more.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-09-08 22:21:37 -04:00
Balamuruhan S
151c32bf5e powerpc/sstep: Add support for divde[.] and divdeu[.] instructions
This patch adds emulation support for divde, divdeu instructions,
  - Divide Doubleword Extended (divde[.])
  - Divide Doubleword Extended Unsigned (divdeu[.])

Signed-off-by: Balamuruhan S <bala24@linux.ibm.com>
Reviewed-by: Sandipan Das <sandipan@linux.ibm.com>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200728130308.1790982-3-bala24@linux.ibm.com
2020-07-29 23:47:52 +10:00
Michael Ellerman
826b07b190 powerpc/sstep: Fix incorrect CONFIG symbol in scv handling
When I "fixed" the ppc64e build in Nick's recent patch, I typoed the
CONFIG symbol, resulting in one that doesn't exist. Fix it to use the
correct symbol.

Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Fixes: 7fa95f9ada ("powerpc/64s: system call support for scv/rfscv instructions")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200724131609.1640533-1-mpe@ellerman.id.au
2020-07-24 23:16:49 +10:00
Michael Ellerman
335aca5f65 Merge branch 'scv' support into next
From Nick's cover letter:

Linux powerpc new system call instruction and ABI

System Call Vectored (scv) ABI
==============================

The scv instruction is introduced with POWER9 / ISA3, it comes with an
rfscv counter-part. The benefit of these instructions is
performance (trading slower SRR0/1 with faster LR/CTR registers, and
entering the kernel with MSR[EE] and MSR[RI] left enabled, which can
reduce MSR updates. The scv instruction has 128 levels (not enough to
cover the Linux system call space).

Assignment and advertisement
----------------------------
The proposal is to assign scv levels conservatively, and advertise
them with HWCAP feature bits as we add support for more.

Linux has not enabled FSCR[SCV] yet, so executing the scv instruction
will cause the kernel to log a "SCV facility unavilable" message, and
deliver a SIGILL with ILL_ILLOPC to the process. Linux has defined a
HWCAP2 bit PPC_FEATURE2_SCV for SCV support, but does not set it.

This change allocates the zero level ('scv 0'), advertised with
PPC_FEATURE2_SCV, which will be used to provide normal Linux system
calls (equivalent to 'sc').

Attempting to execute scv with other levels will cause a SIGILL to be
delivered the same as before, but will not log a "SCV facility
unavailable" message (because the processor facility is enabled).

Calling convention
------------------
The proposal is for scv 0 to provide the standard Linux system call
ABI with the following differences from sc convention[1]:

- LR is to be volatile across scv calls. This is necessary because the
  scv instruction clobbers LR. From previous discussion, this should
  be possible to deal with in GCC clobbers and CFI.

- cr1 and cr5-cr7 are volatile. This matches the C ABI and would allow
  the kernel system call exit to avoid restoring the volatile cr
  registers (although we probably still would anyway to avoid
  information leaks).

- Error handling: The consensus among kernel, glibc, and musl is to
  move to using negative return values in r3 rather than CR0[SO]=1 to
  indicate error, which matches most other architectures, and is
  closer to a function call.

Notes
-----
- r0,r4-r8 are documented as volatile in the ABI, but the kernel patch
  as submitted currently preserves them. This is to leave room for
  deciding which way to go with these. Some small benefit was found by
  preserving them[1] but I'm not convinced it's worth deviating from
  the C function call ABI just for this. Release code should follow
  the ABI.

Previous discussions:
https://lists.ozlabs.org/pipermail/linuxppc-dev/2020-April/208691.html
https://lists.ozlabs.org/pipermail/linuxppc-dev/2020-April/209268.html

[1] https://github.com/torvalds/linux/blob/master/Documentation/powerpc/syscall64-abi.rst
[2] https://lists.ozlabs.org/pipermail/linuxppc-dev/2020-April/209263.html
2020-07-23 17:43:44 +10:00
Balamuruhan S
68a180a44c powerpc/sstep: Introduce macros to retrieve Prefix instruction operands
retrieve prefix instruction operands RA and pc relative bit R values
using macros and adopt it in sstep.c and test_emulate_step.c.

Signed-off-by: Balamuruhan S <bala24@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200626095158.1031507-4-bala24@linux.ibm.com
2020-07-23 17:43:11 +10:00
Nicholas Piggin
7fa95f9ada powerpc/64s: system call support for scv/rfscv instructions
Add support for the scv instruction on POWER9 and later CPUs.

For now this implements the zeroth scv vector 'scv 0', as identical to
'sc' system calls, with the exception that LR is not preserved, nor
are volatile CR registers, and error is not indicated with CR0[SO],
but by returning a negative errno.

rfscv is implemented to return from scv type system calls. It can not
be used to return from sc system calls because those are defined to
preserve LR.

getpid syscall throughput on POWER9 is improved by 26% (428 to 318
cycles), largely due to reducing mtmsr and mtspr.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fix ppc64e build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200611081203.995112-3-npiggin@gmail.com
2020-07-22 23:00:27 +10:00
Jordan Niethe
3920742b92 powerpc sstep: Add support for prefixed fixed-point arithmetic
This adds emulation support for the following prefixed Fixed-Point
Arithmetic instructions:
  * Prefixed Add Immediate (paddi)

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Balamuruhan S <bala24@linux.ibm.com>
[mpe: Squash in get_op() usage]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-31-jniethe5@gmail.com
2020-05-19 00:11:03 +10:00
Jordan Niethe
50b80a12e4 powerpc sstep: Add support for prefixed load/stores
This adds emulation support for the following prefixed integer
load/stores:
  * Prefixed Load Byte and Zero (plbz)
  * Prefixed Load Halfword and Zero (plhz)
  * Prefixed Load Halfword Algebraic (plha)
  * Prefixed Load Word and Zero (plwz)
  * Prefixed Load Word Algebraic (plwa)
  * Prefixed Load Doubleword (pld)
  * Prefixed Store Byte (pstb)
  * Prefixed Store Halfword (psth)
  * Prefixed Store Word (pstw)
  * Prefixed Store Doubleword (pstd)
  * Prefixed Load Quadword (plq)
  * Prefixed Store Quadword (pstq)

the follow prefixed floating-point load/stores:
  * Prefixed Load Floating-Point Single (plfs)
  * Prefixed Load Floating-Point Double (plfd)
  * Prefixed Store Floating-Point Single (pstfs)
  * Prefixed Store Floating-Point Double (pstfd)

and for the following prefixed VSX load/stores:
  * Prefixed Load VSX Scalar Doubleword (plxsd)
  * Prefixed Load VSX Scalar Single-Precision (plxssp)
  * Prefixed Load VSX Vector [0|1]  (plxv, plxv0, plxv1)
  * Prefixed Store VSX Scalar Doubleword (pstxsd)
  * Prefixed Store VSX Scalar Single-Precision (pstxssp)
  * Prefixed Store VSX Vector [0|1] (pstxv, pstxv0, pstxv1)

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Balamuruhan S <bala24@linux.ibm.com>
[mpe: Use CONFIG_PPC64 not __powerpc64__, use get_op()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-30-jniethe5@gmail.com
2020-05-19 00:11:03 +10:00
Jordan Niethe
650b55b707 powerpc: Add prefixed instructions to instruction data type
For powerpc64, redefine the ppc_inst type so both word and prefixed
instructions can be represented. On powerpc32 the type will remain the
same. Update places which had assumed instructions to be 4 bytes long.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
[mpe: Rework the get_user_inst() macros to be parameterised, and don't
      assign to the dest if an error occurred. Use CONFIG_PPC64 not
      __powerpc64__ in a few places. Address other comments from
      Christophe. Fix some sparse complaints.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-24-jniethe5@gmail.com
2020-05-19 00:10:39 +10:00
Jordan Niethe
94afd069d9 powerpc: Use a datatype for instructions
Currently unsigned ints are used to represent instructions on powerpc.
This has worked well as instructions have always been 4 byte words.

However, ISA v3.1 introduces some changes to instructions that mean
this scheme will no longer work as well. This change is Prefixed
Instructions. A prefixed instruction is made up of a word prefix
followed by a word suffix to make an 8 byte double word instruction.
No matter the endianness of the system the prefix always comes first.
Prefixed instructions are only planned for powerpc64.

Introduce a ppc_inst type to represent both prefixed and word
instructions on powerpc64 while keeping it possible to exclusively
have word instructions on powerpc32.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
[mpe: Fix compile error in emulate_spe()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-12-jniethe5@gmail.com
2020-05-19 00:10:37 +10:00
Jordan Niethe
8094892d1a powerpc: Use a function for getting the instruction op code
In preparation for using a data type for instructions that can not be
directly used with the '>>' operator use a function for getting the op
code of an instruction.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-9-jniethe5@gmail.com
2020-05-19 00:10:37 +10:00
Jordan Niethe
777e26f0ed powerpc: Use an accessor for instructions
In preparation for introducing a more complicated instruction type to
accommodate prefixed instructions use an accessor for getting an
instruction as a u32.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-8-jniethe5@gmail.com
2020-05-19 00:10:36 +10:00
Nicholas Piggin
f14f8a2032 powerpc/64/sstep: Ifdef the deprecated fast endian switch syscall
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-25-npiggin@gmail.com
2020-04-01 13:42:13 +11:00
Thomas Gleixner
2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00
Sandipan Das
6324320de6 powerpc sstep: Add support for modsd, modud instructions
This adds emulation support for the following integer instructions:
  * Modulo Signed Doubleword (modsd)
  * Modulo Unsigned Doubleword (modud)

Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-26 00:05:20 +11:00
PrasannaKumar Muralidharan
6c18007150 powerpc sstep: Add support for modsw, moduw instructions
This adds emulation support for the following integer instructions:
  * Modulo Signed Word (modsw)
  * Modulo Unsigned Word (moduw)

Signed-off-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-26 00:05:19 +11:00
Sandipan Das
3e751acba2 powerpc sstep: Add support for extswsli instruction
This adds emulation support for the following integer instructions:
  * Extend-Sign Word and Shift Left Immediate (extswsli[.])

Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-26 00:05:18 +11:00
Sandipan Das
32628b5cf3 powerpc sstep: Add support for cnttzw, cnttzd instructions
This adds emulation support for the following integer instructions:
  * Count Trailing Zeros Word (cnttzw[.])
  * Count Trailing Zeros Doubleword (cnttzd[.])

Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-26 00:05:17 +11:00
Sandipan Das
a23987ef26 powerpc: sstep: Add support for darn instruction
This adds emulation support for the following integer instructions:
  * Deliver A Random Number (darn)

As suggested by Michael, this uses a raw .long for specifying the
instruction word when using inline assembly to retain compatibility
with older binutils.

Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-26 00:05:17 +11:00
Sandipan Das
930d6288a2 powerpc: sstep: Add support for maddhd, maddhdu, maddld instructions
This adds emulation support for the following integer instructions:
  * Multiply-Add High Doubleword (maddhd)
  * Multiply-Add High Doubleword Unsigned (maddhdu)
  * Multiply-Add Low Doubleword (maddld)

As suggested by Michael, this uses a raw .long for specifying the
instruction word when using inline assembly to retain compatibility
with older binutils.

Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-26 00:05:16 +11:00
Ravi Bangoria
83afab4ce0 powerpc/sstep: Fix kernel crash if VSX is not present
emulate_step() is not checking runtime VSX feature flag before
emulating an instruction. This is causing kernel crash when kernel
is compiled with CONFIG_VSX=y but running on a machine where VSX
is not supported or disabled. Ex, while running emulate_step tests
on P6 machine:

  Oops: Exception in kernel mode, sig: 4 [#1]
  NIP [c000000000095c24] .load_vsrn+0x28/0x54
  LR [c000000000094bdc] .emulate_loadstore+0x167c/0x17b0
  Call Trace:
    0x40fe240c7ae147ae (unreliable)
    .emulate_loadstore+0x167c/0x17b0
    .emulate_step+0x25c/0x5bc
    .test_lxvd2x_stxvd2x+0x64/0x154
    .test_emulate_step+0x38/0x4c
    .do_one_initcall+0x5c/0x2c0
    .kernel_init_freeable+0x314/0x4cc
    .kernel_init+0x24/0x160
    .ret_from_kernel_thread+0x58/0xb4

With fix:
  emulate_step_test: lxvd2x         : FAIL
  emulate_step_test: stxvd2x        : FAIL

Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-04 00:39:08 +10:00
Ravi Bangoria
e6684d07e4 powerpc/sstep: Introduce GETTYPE macro
Replace 'op->type & INSTR_TYPE_MASK' expression with GETTYPE(op->type)
macro.

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 21:19:40 +10:00
Finn Thain
20acf7fc94 powerpc/lib: Fix "integer constant is too large" build failure
My powerpc-linux-gnu-gcc v4.4.5 compiler can't build a 32-bit kernel
any more:

arch/powerpc/lib/sstep.c: In function 'do_popcnt':
arch/powerpc/lib/sstep.c:1068: error: integer constant is too large for 'long' type
arch/powerpc/lib/sstep.c:1069: error: integer constant is too large for 'long' type
arch/powerpc/lib/sstep.c:1069: error: integer constant is too large for 'long' type
arch/powerpc/lib/sstep.c:1070: error: integer constant is too large for 'long' type
arch/powerpc/lib/sstep.c:1079: error: integer constant is too large for 'long' type
arch/powerpc/lib/sstep.c: In function 'do_prty':
arch/powerpc/lib/sstep.c:1117: error: integer constant is too large for 'long' type

This file gets compiled with -std=gnu89 which means a constant can be
given the type 'long' even if it won't fit. Fix the errors with a 'ULL'
suffix on the relevant constants.

Fixes: 2c979c489f ("powerpc/lib/sstep: Add prty instruction emulation")
Fixes: dcbd19b48d ("powerpc/lib/sstep: Add popcnt instruction emulation")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-18 16:04:02 +10:00
Mathieu Malaterre
174b701d3d powerpc/32: Move the inline keyword at the beginning of function declaration
The inline keyword was not at the beginning of the function declaration.
Fix the following warning (treated as error in W=1):

  arch/powerpc/lib/sstep.c:283:1: error: ‘inline’ is not at beginning of declaration
   static int nokprobe_inline copy_mem_in(u8 *dest, unsigned long ea, int nb,
  arch/powerpc/lib/sstep.c:388:1: error: ‘inline’ is not at beginning of declaration
   static int nokprobe_inline copy_mem_out(u8 *dest, unsigned long ea, int nb,

Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-13 15:50:33 +11:00
Naveen N. Rao
67ac0bfe29 powerpc/kprobes: Blacklist emulate_update_regs() from kprobes
Commit 3cdfcbfd32 ("powerpc: Change analyse_instr so it doesn't
modify *regs") introduced emulate_update_regs() to perform part of what
emulate_step() was doing earlier. However, this function was not added
to the kprobes blacklist. Add it so as to prevent it from being probed.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-12 23:51:42 +11:00
Michael Ellerman
a54c61f46e Merge branch 'fixes' into next
We have some dependencies & conflicts between patches in fixes and
things to go in next, both in the radix TLB flush code and the IMC PMU
driver. So merge fixes into next.
2017-11-10 20:55:03 +11:00
Sandipan Das
b0490a04e7 powerpc/lib/sstep: Fix count leading zeros instructions
According to the GCC documentation, the behaviour of __builtin_clz()
and __builtin_clzl() is undefined if the value of the input argument
is zero. Without handling this special case, these builtins have been
used for emulating the following instructions:
  * Count Leading Zeros Word (cntlzw[.])
  * Count Leading Zeros Doubleword (cntlzd[.])

This fixes the emulated behaviour of these instructions by adding an
additional check for this special case.

Fixes: 3cdfcbfd32 ("powerpc: Change analyse_instr so it doesn't modify *regs")
Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-10 20:16:32 +11:00
Sandipan Das
0a75aff178 powerpc/lib/sstep: Fix fixed-point shift instructions that set CA32
This fixes the emulated behaviour of existing fixed-point shift right
algebraic instructions that are supposed to set both the CA and CA32
bits of XER when running on a system that is compliant with POWER ISA
v3.0 independent of whether the system is executing in 32-bit mode or
64-bit mode. The following instructions are affected:
  * Shift Right Algebraic Word Immediate (srawi[.])
  * Shift Right Algebraic Word (sraw[.])
  * Shift Right Algebraic Doubleword Immediate (sradi[.])
  * Shift Right Algebraic Doubleword (srad[.])

Fixes: 0016a4cf55 ("powerpc: Emulate most Book I instructions in emulate_step()")
Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04 11:28:04 +11:00
Sandipan Das
dc39c1d68f powerpc/lib/sstep: Fix fixed-point arithmetic instructions that set CA32
There are existing fixed-point arithmetic instructions that always set the
CA bit of XER to reflect the carry out of bit 0 in 64-bit mode and out of
bit 32 in 32-bit mode. In ISA v3.0, these instructions also always set the
CA32 bit of XER to reflect the carry out of bit 32.

This fixes the emulated behaviour of such instructions when running on a
system that is compliant with POWER ISA v3.0. The following instructions
are affected:
  * Add Immediate Carrying (addic)
  * Add Immediate Carrying and Record (addic.)
  * Subtract From Immediate Carrying (subfic)
  * Add Carrying (addc[.])
  * Subtract From Carrying (subfc[.])
  * Add Extended (adde[.])
  * Subtract From Extended (subfe[.])
  * Add to Minus One Extended (addme[.])
  * Subtract From Minus One Extended (subfme[.])
  * Add to Zero Extended (addze[.])
  * Subtract From Zero Extended (subfze[.])

Fixes: 0016a4cf55 ("powerpc: Emulate most Book I instructions in emulate_step()")
Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04 11:28:03 +11:00
Sandipan Das
924c8feb04 powerpc/lib/sstep: Add XER bits introduced in POWER ISA v3.0
This adds definitions for the OV32 and CA32 bits of XER that
were introduced in POWER ISA v3.0. There are some existing
instructions that currently set the OV and CA bits based on
certain conditions.

The emulation behaviour of all these instructions needs to
be updated to set these new bits accordingly.

Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04 11:28:03 +11:00
Anton Blanchard
1575fe06f6 powerpc/sstep: mullw should calculate a 64 bit signed result
mullw should do a 32 bit signed multiply and create a 64 bit signed
result. It currently truncates the result to 32 bits.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:30:09 +10:00
Anton Blanchard
5bcaa4cc41 powerpc/sstep: Fix issues with mcrf
mcrf broke when we changed analyse_instr() to not modify the register
state. The instruction writes to the CR, so we need to store the result
in op->ccval, not op->val.

Fixes: 3cdfcbfd32 ("powerpc: Change analyse_instr so it doesn't modify *regs")
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:30:09 +10:00
Anton Blanchard
ad47ff3e33 powerpc/sstep: Fix issues with set_cr0()
set_cr0() broke when we changed analyse_instr() to not modify the
register state. Instead of looking at regs->gpr[x] which has not
been updated yet, we need to look at op->val.

Fixes: 3cdfcbfd32 ("powerpc: Change analyse_instr so it doesn't modify *regs")
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:30:09 +10:00
Michael Ellerman
3b79b26101 powerpc/sstep: Avoid used uninitialized error
Older compilers think val may be used uninitialized:

  arch/powerpc/lib/sstep.c: In function 'emulate_loadstore':
  arch/powerpc/lib/sstep.c:2758:23: error: 'val' may be used uninitialized in this function

We know better, but initialise val to 0 to avoid breaking the build.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-02 08:04:26 +10:00
Paul Mackerras
45f62159f3 powerpc: Wrap register number correctly for string load/store instructions
Michael Ellerman reported that emulate_loadstore() was trying to
access element 32 of regs->gpr[], which doesn't exist, when
emulating a string store instruction.  This is because the string
load and store instructions (lswi, lswx, stswi and stswx) are
defined to wrap around from register 31 to register 0 if the number
of bytes being loaded or stored is sufficiently large.  This wrapping
was not implemented in the emulation code.  To fix it, we mask the
register number after incrementing it.

Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Fixes: c9f6f4ed95 ("powerpc: Implement emulation of string loads and stores")
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-01 16:42:44 +10:00
Paul Mackerras
d2b65ac652 powerpc: Emulate load/store floating point as integer word instructions
This adds emulation for the lfiwax, lfiwzx and stfiwx instructions.
This necessitated adding a new flag to indicate whether a floating
point or an integer conversion was needed for LOAD_FP and STORE_FP,
so this moves the size field in op->type up 4 bits.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-01 16:42:44 +10:00