6345 Commits

Author SHA1 Message Date
Mathieu Malaterre
86e11b6e9c powerpc: Make function btext_initialize static
This function can be static, make it so, this fix a warning treated as
error with W=1:

  arch/powerpc/kernel/btext.c:173:5: error: no previous prototype for ‘btext_initialize’ [-Werror=missing-prototypes]

Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-25 12:04:44 +10:00
Mathieu Malaterre
bd13ac95f9 powerpc/tau: Synchronize function prototypes and body
Some function prototypes and body for Thermal Assist Units were not in
sync. Update the function definition to match the existing function
declaration found in `setup-common.c`, changing an `int` return type to a
`u32` return type. Move the prototypes to a header file. Fix the following
warnings, treated as error with W=1:

  arch/powerpc/kernel/tau_6xx.c:257:5: error: no previous prototype for ‘cpu_temp_both’ [-Werror=missing-prototypes]
  arch/powerpc/kernel/tau_6xx.c:262:5: error: no previous prototype for ‘cpu_temp’ [-Werror=missing-prototypes]
  arch/powerpc/kernel/tau_6xx.c:267:5: error: no previous prototype for ‘tau_interrupts’ [-Werror=missing-prototypes]

Compile tested with CONFIG_TAU_INT.

Suggested-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-25 12:04:43 +10:00
Mathieu Malaterre
85aa4b9841 powerpc/mm/radix: Use do/while(0) trick for single statement block
In commit 7a22d6321c3d ("powerpc/mm/radix: Update command line parsing for
disable_radix") an `if` statement was added for a possible empty body
(prom_debug).

Fix the following warning, treated as error with W=1:

  arch/powerpc/kernel/prom_init.c:656:46: error: suggest braces around empty body in an ‘if’ statement [-Werror=empty-body]

Suggested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-25 12:04:39 +10:00
Mathieu Malaterre
d8731527ac powerpc/sparse: Fix plain integer as NULL pointer warning
Trivial fix to remove the following sparse warnings:

  arch/powerpc/kernel/module_32.c:112:74: warning: Using plain integer as NULL pointer
  arch/powerpc/kernel/module_32.c:117:74: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:1155:28: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:1230:20: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:1385:36: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:1752:23: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:2084:19: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:2110:32: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:2167:19: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:2183:19: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:277:20: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/setup.c:155:67: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/setup.c:247:27: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/setup.c:249:27: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/setup.c:252:37: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/tlb_hash32.c:127:21: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/tlb_hash32.c:148:21: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/tlb_hash32.c:44:21: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/tlb_hash32.c:57:21: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/tlb_hash32.c:87:21: warning: Using plain integer as NULL pointer
  arch/powerpc/kernel/btext.c:160:31: warning: Using plain integer as NULL pointer
  arch/powerpc/kernel/btext.c:167:22: warning: Using plain integer as NULL pointer
  arch/powerpc/kernel/btext.c:274:21: warning: Using plain integer as NULL pointer
  arch/powerpc/kernel/btext.c:285:31: warning: Using plain integer as NULL pointer
  arch/powerpc/include/asm/hugetlb.h:204:16: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/ppc_mmu_32.c:170:21: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/pci.c:1227:23: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/pci.c:65:24: warning: Using plain integer as NULL pointer

Also use `--fix` command line option from `script/checkpatch --strict` to
remove the following:

  CHECK: Comparison to NULL could be written "!dispDeviceBase"
  #72: FILE: arch/powerpc/kernel/btext.c:160:
  +	if (dispDeviceBase == NULL)

  CHECK: Comparison to NULL could be written "!vbase"
  #80: FILE: arch/powerpc/kernel/btext.c:167:
  +	if (vbase == NULL)

  CHECK: Comparison to NULL could be written "!base"
  #89: FILE: arch/powerpc/kernel/btext.c:274:
  +	if (base == NULL)

  CHECK: Comparison to NULL could be written "!dispDeviceBase"
  #98: FILE: arch/powerpc/kernel/btext.c:285:
  +	if (dispDeviceBase == NULL)

  CHECK: Comparison to NULL could be written "strstr"
  #117: FILE: arch/powerpc/kernel/module_32.c:117:
  +		if (strstr(secstrings + sechdrs[i].sh_name, ".debug") != NULL)

  CHECK: Comparison to NULL could be written "!Hash"
  #130: FILE: arch/powerpc/mm/ppc_mmu_32.c:170:
  +	if (Hash == NULL)

  CHECK: Comparison to NULL could be written "Hash"
  #143: FILE: arch/powerpc/mm/tlb_hash32.c:44:
  +	if (Hash != NULL) {

  CHECK: Comparison to NULL could be written "!Hash"
  #152: FILE: arch/powerpc/mm/tlb_hash32.c:57:
  +	if (Hash == NULL) {

  CHECK: Comparison to NULL could be written "!Hash"
  #161: FILE: arch/powerpc/mm/tlb_hash32.c:87:
  +	if (Hash == NULL) {

  CHECK: Comparison to NULL could be written "!Hash"
  #170: FILE: arch/powerpc/mm/tlb_hash32.c:127:
  +	if (Hash == NULL) {

  CHECK: Comparison to NULL could be written "!Hash"
  #179: FILE: arch/powerpc/mm/tlb_hash32.c:148:
  +	if (Hash == NULL) {

  ERROR: space required after that ';' (ctx:VxV)
  #192: FILE: arch/powerpc/platforms/powermac/pci.c:65:
  +	for (; node != NULL;node = node->sibling) {

  CHECK: Comparison to NULL could be written "node"
  #192: FILE: arch/powerpc/platforms/powermac/pci.c:65:
  +	for (; node != NULL;node = node->sibling) {

  CHECK: Comparison to NULL could be written "!region"
  #201: FILE: arch/powerpc/platforms/powermac/pci.c:1227:
  +	if (region == NULL)

  CHECK: Comparison to NULL could be written "of_get_property"
  #214: FILE: arch/powerpc/platforms/powermac/setup.c:155:
  +		if (of_get_property(np, "cache-unified", NULL) != NULL && dc) {

  CHECK: Comparison to NULL could be written "!np"
  #223: FILE: arch/powerpc/platforms/powermac/setup.c:247:
  +		if (np == NULL)

  CHECK: Comparison to NULL could be written "np"
  #226: FILE: arch/powerpc/platforms/powermac/setup.c:249:
  +		if (np != NULL) {

  CHECK: Comparison to NULL could be written "l2cr"
  #230: FILE: arch/powerpc/platforms/powermac/setup.c:252:
  +			if (l2cr != NULL) {

  CHECK: Comparison to NULL could be written "via"
  #243: FILE: drivers/macintosh/via-pmu.c:277:
  +	if (via != NULL)

  CHECK: Comparison to NULL could be written "current_req"
  #252: FILE: drivers/macintosh/via-pmu.c:1155:
  +	if (current_req != NULL) {

  CHECK: Comparison to NULL could be written "!req"
  #261: FILE: drivers/macintosh/via-pmu.c:1230:
  +	if (req == NULL || pmu_state != idle

  CHECK: Comparison to NULL could be written "!req"
  #270: FILE: drivers/macintosh/via-pmu.c:1385:
  +			if (req == NULL) {

  CHECK: Comparison to NULL could be written "!pp"
  #288: FILE: drivers/macintosh/via-pmu.c:2084:
  +	if (pp == NULL)

  CHECK: Comparison to NULL could be written "!pp"
  #297: FILE: drivers/macintosh/via-pmu.c:2110:
  +	if (count < 1 || pp == NULL)

  CHECK: Comparison to NULL could be written "!pp"
  #306: FILE: drivers/macintosh/via-pmu.c:2167:
  +	if (pp == NULL)

  CHECK: Comparison to NULL could be written "pp"
  #315: FILE: drivers/macintosh/via-pmu.c:2183:
  +	if (pp != NULL) {

Link: https://github.com/linuxppc/linux/issues/37
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-25 12:04:38 +10:00
Mathieu Malaterre
eae5f709a4 powerpc: Add __printf verification to prom_printf
__printf is useful to verify format and arguments. Fix arg mismatch
reported by gcc, remove the following warnings (with W=1):

  arch/powerpc/kernel/prom_init.c:1467:31: error: format ‘%x’ expects argument of type ‘unsigned int’, but argument 2 has type ‘long unsigned int’
  arch/powerpc/kernel/prom_init.c:1471:31: error: format ‘%x’ expects argument of type ‘unsigned int’, but argument 2 has type ‘long unsigned int’
  arch/powerpc/kernel/prom_init.c:1504:33: error: format ‘%x’ expects argument of type ‘unsigned int’, but argument 2 has type ‘long unsigned int’
  arch/powerpc/kernel/prom_init.c:1505:33: error: format ‘%x’ expects argument of type ‘unsigned int’, but argument 2 has type ‘long unsigned int’
  arch/powerpc/kernel/prom_init.c:1506:33: error: format ‘%x’ expects argument of type ‘unsigned int’, but argument 2 has type ‘long unsigned int’
  arch/powerpc/kernel/prom_init.c:1507:33: error: format ‘%x’ expects argument of type ‘unsigned int’, but argument 2 has type ‘long unsigned int’
  arch/powerpc/kernel/prom_init.c:1508:33: error: format ‘%x’ expects argument of type ‘unsigned int’, but argument 2 has type ‘long unsigned int’
  arch/powerpc/kernel/prom_init.c:1509:33: error: format ‘%x’ expects argument of type ‘unsigned int’, but argument 2 has type ‘long unsigned int’
  arch/powerpc/kernel/prom_init.c:1975:39: error: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘unsigned int’
  arch/powerpc/kernel/prom_init.c:1986:27: error: format ‘%x’ expects argument of type ‘unsigned int’, but argument 2 has type ‘long unsigned int’
  arch/powerpc/kernel/prom_init.c:2567:38: error: format ‘%x’ expects argument of type ‘unsigned int’, but argument 2 has type ‘long unsigned int’
  arch/powerpc/kernel/prom_init.c:2567:46: error: format ‘%x’ expects argument of type ‘unsigned int’, but argument 3 has type ‘long unsigned int’
  arch/powerpc/kernel/prom_init.c:2569:38: error: format ‘%x’ expects argument of type ‘unsigned int’, but argument 2 has type ‘long unsigned int’
  arch/powerpc/kernel/prom_init.c:2569:46: error: format ‘%x’ expects argument of type ‘unsigned int’, but argument 3 has type ‘long unsigned int’

The patch also include arg mismatch fix for case with #define DEBUG_PROM
(warning not listed here).

This patch fix also the following warnings revealed by checkpatch:

  WARNING: Prefer using '"%s...", __func__' to using 'alloc_up', this function's name, in a string
  #101: FILE: arch/powerpc/kernel/prom_init.c:1235:
  + prom_debug("alloc_up(%lx, %lx)\n", size, align);

and

  WARNING: Prefer using '"%s...", __func__' to using 'alloc_down', this function's name, in a string
  #138: FILE: arch/powerpc/kernel/prom_init.c:1278:
  + prom_debug("alloc_down(%lx, %lx, %s)\n", size, align,

Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-25 12:04:37 +10:00
Christophe Leroy
e4ccb1dae6 powerpc/8xx: fix invalid register expression in head_8xx.S
New binutils generate the following warning

  AS      arch/powerpc/kernel/head_8xx.o
arch/powerpc/kernel/head_8xx.S: Assembler messages:
arch/powerpc/kernel/head_8xx.S:916: Warning: invalid register expression

This patch fixes it.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-25 00:08:26 +10:00
Simon Guo
eacbb218fb powerpc: Export tm_enable()/tm_disable/tm_abort() APIs
This patch exports tm_enable()/tm_disable/tm_abort() APIs, which
will be used for PR KVM transactional memory logic.

Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Reviewed-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-24 16:04:02 +10:00
Simon Guo
d1c7211281 powerpc: Export msr_check_and_set() to modules
PR KVM will need to reuse msr_check_and_set().
This patch exports this API for reuse.

Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Reviewed-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-24 16:03:24 +10:00
Nicholas Piggin
a048a07d7f powerpc/64s: Add support for a store forwarding barrier at kernel entry/exit
On some CPUs we can prevent a vulnerability related to store-to-load
forwarding by preventing store forwarding between privilege domains,
by inserting a barrier in kernel entry and exit paths.

This is known to be the case on at least Power7, Power8 and Power9
powerpc CPUs.

Barriers must be inserted generally before the first load after moving
to a higher privilege, and after the last store before moving to a
lower privilege, HV and PR privilege transitions must be protected.

Barriers are added as patch sections, with all kernel/hypervisor entry
points patched, and the exit points to lower privilge levels patched
similarly to the RFI flush patching.

Firmware advertisement is not implemented yet, so CPU flush types
are hard coded.

Thanks to Michal Suchánek for bug fixes and review.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michal Suchánek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-05-21 20:45:31 -07:00
Michael Neuling
4f7c06e26e powerpc/ptrace: Fix setting 512B aligned breakpoints with PTRACE_SET_DEBUGREG
In commit e2a800beaca1 ("powerpc/hw_brk: Fix off by one error when
validating DAWR region end") we fixed setting the DAWR end point to
its max value via PPC_PTRACE_SETHWDEBUG. Unfortunately we broke
PTRACE_SET_DEBUGREG when setting a 512 byte aligned breakpoint.

PTRACE_SET_DEBUGREG currently sets the length of the breakpoint to
zero (memset() in hw_breakpoint_init()). This worked with
arch_validate_hwbkpt_settings() before the above patch was applied but
is now broken if the breakpoint is 512byte aligned.

This sets the length of the breakpoint to 8 bytes when using
PTRACE_SET_DEBUGREG.

Fixes: e2a800beaca1 ("powerpc/hw_brk: Fix off by one error when validating DAWR region end")
Cc: stable@vger.kernel.org # v3.11+
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-21 14:48:01 +10:00
Michael Neuling
cd6ef7eebf powerpc/ptrace: Fix enforcement of DAWR constraints
Back when we first introduced the DAWR, in commit 4ae7ebe9522a
("powerpc: Change hardware breakpoint to allow longer ranges"), we
screwed up the constraint making it a 1024 byte boundary rather than a
512. This makes the check overly permissive. Fortunately GDB is the
only real user and it always did they right thing, so we never
noticed.

This fixes the constraint to 512 bytes.

Fixes: 4ae7ebe9522a ("powerpc: Change hardware breakpoint to allow longer ranges")
Cc: stable@vger.kernel.org # v3.9+
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-21 14:47:44 +10:00
Colin Ian King
ba01b058a5 powerpc/rtas: Fix spelling mistake "Discharching" -> "Discharging"
Trivial fix to spelling mistake in battery_charging array.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-18 21:55:01 +10:00
Michael Neuling
faf37c44a1 powerpc/64s: Clear PCR on boot
Clear the PCR (Processor Compatibility Register) on boot to ensure we
are not running in a compatibility mode.

We've seen this cause problems when a crash (and kdump) occurs while
running compat mode guests. The kdump kernel then runs with the PCR
set and causes problems. The symptom in the kdump kernel (also seen in
petitboot after fast-reboot) is early userspace programs taking
sigills on newer instructions (seen in libc).

Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-18 16:05:15 +10:00
Simon Guo
173c520a04 KVM: PPC: Move nip/ctr/lr/xer registers to pt_regs in kvm_vcpu_arch
This patch moves nip/ctr/lr/xer registers from scattered places in
kvm_vcpu_arch to pt_regs structure.

cr register is "unsigned long" in pt_regs and u32 in vcpu->arch.
It will need more consideration and may move in later patches.

Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18 15:38:23 +10:00
Simon Guo
1143a70665 KVM: PPC: Add pt_regs into kvm_vcpu_arch and move vcpu->arch.gpr[] into it
Current regs are scattered at kvm_vcpu_arch structure and it will
be more neat to organize them into pt_regs structure.

Also it will enable reimplementation of MMIO emulation code with
analyse_instr() later.

Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18 15:38:23 +10:00
Paul Mackerras
9c9e9cf40a Merge remote-tracking branch 'remotes/powerpc/topic/ppc-kvm' into kvm-ppc-next
This merges in the ppc-kvm topic branch of the powerpc repository
to get some changes on which future patches will depend, in particular
the definitions of various new TLB flushing functions.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18 15:30:10 +10:00
Christophe Leroy
a1f3ae3fe8 powerpc/32: Use stmw/lmw for registers save/restore in asm
arch/powerpc/Makefile activates -mmultiple on BE PPC32 configs
in order to use multiple word instructions in functions entry/exit.

The patch does the same for the asm parts, for consistency.

On processors like the 8xx on which insn fetching is pretty slow,
this speeds up registers save/restore.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: PPC32 is BE only, so drop the endian checks]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-18 00:09:06 +10:00
Christophe Leroy
24c78586cc powerpc: Avoid an unnecessary test and branch in longjmp()
Doing the test at exit of the function avoids an unnecessary
test and branch inside longjmp().

Semantics are unchanged.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-18 00:09:05 +10:00
Nicholas Piggin
4c1d9bb0b5 powerpc: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selected
This requires further changes to linker script to KEEP some tables
and wildcard compiler generated sections into the right place. This
includes pp32 modifications from Christophe Leroy.

When compiling powernv_defconfig with this option, the resulting
kernel is almost 400kB smaller (and still boots):

    text      data       bss        dec   filename
11827621   4810490   1341080   17979191   vmlinux
11752437   4598858   1338776   17690071   vmlinux.dcde

Mathieu's numbers for custom Mac Mini G4 config has almost 200kB
saving. It also had some increase in vmlinux size for as-yet
unknown reasons.

    text      data       bss        dec   filename
 7461457   2475122   1428064   11364643   vmlinux
 7386425   2364370   1425432   11176227   vmlinux.dcde

Tested-by: Christophe Leroy <christophe.leroy@c-s.fr> [8xx]
Tested-by: Mathieu Malaterre <malat@debian.org> [32-bit powermac]
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-17 22:45:01 +09:00
Paul Mackerras
57b8daa70a KVM: PPC: Book3S HV: Snapshot timebase offset on guest entry
Currently, the HV KVM guest entry/exit code adds the timebase offset
from the vcore struct to the timebase on guest entry, and subtracts
it on guest exit.  Which is fine, except that it is possible for
userspace to change the offset using the SET_ONE_REG interface while
the vcore is running, as there is only one timebase offset per vcore
but potentially multiple VCPUs in the vcore.  If that were to happen,
KVM would subtract a different offset on guest exit from that which
it had added on guest entry, leading to the timebase being out of sync
between cores in the host, which then leads to bad things happening
such as hangs and spurious watchdog timeouts.

To fix this, we add a new field 'tb_offset_applied' to the vcore struct
which stores the offset that is currently applied to the timebase.
This value is set from the vcore tb_offset field on guest entry, and
is what is subtracted from the timebase on guest exit.  Since it is
zero when the timebase offset is not applied, we can simplify the
logic in kvmhv_start_timing and kvmhv_accumulate_time.

In addition, we had secondary threads reading the timebase while
running concurrently with code on the primary thread which would
eventually add or subtract the timebase offset from the timebase.
This occurred while saving or restoring the DEC register value on
the secondary threads.  Although no specific incorrect behaviour has
been observed, this is a race which should be fixed.  To fix it, we
move the DEC saving code to just before we call kvmhv_commence_exit,
and the DEC restoring code to after the point where we have waited
for the primary thread to switch the MMU context and add the timebase
offset.  That way we are sure that the timebase contains the guest
timebase value in both cases.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-17 15:16:45 +10:00
Mathieu Malaterre
9f9eae5ce7 powerpc/kvm: Prefer fault_in_pages_readable function
Directly use fault_in_pages_readable instead of manual __get_user code. Fix
warning treated as error with W=1:

  arch/powerpc/kernel/kvm.c:675:6: error: variable ‘tmp’ set but not used [-Werror=unused-but-set-variable]

Suggested-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-17 14:12:40 +10:00
Christoph Hellwig
3f3942aca6 proc: introduce proc_create_single{,_data}
Variants of proc_create{,_data} that directly take a seq_file show
callback and drastically reduces the boilerplate code in the callers.

All trivial callers converted over.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-16 07:23:35 +02:00
Michael Ellerman
89c1906272 powerpc/prom: Drop support for old FDT versions
In commit e6a6928c3ea1 ("of/fdt: Convert FDT functions to use
libfdt") (Apr 2014), the generic flat device tree code dropped support
for flat device tree's older than version 0x10 (16).

We still have code in our CPU scanning to cope with flat device tree
versions earlier than 2, which can now never trigger, so drop it.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-11 23:29:04 +10:00
Michael Ellerman
53da14d083 powerpc: Make it clearer that systbl check errors are errors
If the systbl_chk.sh checks fail we print a message, but with no
indication that it's an error. That makes it hard to find in build
logs with eg. grep.

So prefix any output with "Error:".

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:16 +10:00
Al Viro
28b9c34aa6 powerpc/syscalls: kill ppc32_select()
it had always been pointless - compat_sys_select() sign-extends
the first argument just fine on its own.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[mpe: Use COMPAT_SPU_NEW() to keep systbl_chk.sh happy]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:15 +10:00
Michael Ellerman
454d7ef81a powerpc/syscalls: Add COMPAT_SPU_NEW() macro
Currently the select system call is wired up with the SYSX_SPU()
macro. The SYSX_SPU() is not handled by systbl_chk.c, which means the
syscall number for select is not checked.

That hides the fact that the syscall number for select is actually
__NR__newselect not __NR_select.

In a following patch we'd like to drop ppc32_select() which means
select will become a regular COMPAT_SYS_SPU() syscall. But
COMPAT_SYS_SPU() can't deal with the fact that the syscall number is
actually __NR__newselect. We also can't just redefine __NR_select
because that's still used for the old select call.

So add a new COMPAT_NEW_SPU() that does the same thing as
COMPAT_SYS_SPU() except it encodes that we're using the new number.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:14 +10:00
Al Viro
4c392e6591 powerpc/syscalls: switch rtas(2) to SYSCALL_DEFINE
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[mpe: Update sys_ni.c for s/ppc_rtas/sys_rtas/]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:14 +10:00
Al Viro
f3675644e1 powerpc/syscalls: signal_{32, 64} - switch to SYSCALL_DEFINE
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[mpe: Fix sys_debug_setcontext() prototype to return long]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:13 +10:00
Al Viro
3691d61455 powerpc/syscalls: Switch trivial cases to SYSCALL_DEFINE
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:12 +10:00
Torsten Duwe
df78d3f614 powerpc/livepatch: Implement reliable stack tracing for the consistency model
The "Power Architecture 64-Bit ELF V2 ABI" says in section 2.3.2.3:

[...] There are several rules that must be adhered to in order to ensure
reliable and consistent call chain backtracing:

* Before a function calls any other function, it shall establish its
  own stack frame, whose size shall be a multiple of 16 bytes.

 – In instances where a function’s prologue creates a stack frame, the
   back-chain word of the stack frame shall be updated atomically with
   the value of the stack pointer (r1) when a back chain is implemented.
   (This must be supported as default by all ELF V2 ABI-compliant
   environments.)
[...]
 – The function shall save the link register that contains its return
   address in the LR save doubleword of its caller’s stack frame before
   calling another function.

To me this sounds like the equivalent of HAVE_RELIABLE_STACKTRACE.
This patch may be unneccessarily limited to ppc64le, but OTOH the only
user of this flag so far is livepatching, which is only implemented on
PPCs with 64-LE, a.k.a. ELF ABI v2.

Feel free to add other ppc variants, but so far only ppc64le got tested.

This change also implements save_stack_trace_tsk_reliable() for ppc64le
that checks for the above conditions, where possible.

Signed-off-by: Torsten Duwe <duwe@suse.de>
Signed-off-by: Nicolai Stange <nstange@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:12 +10:00
Nicholas Piggin
4e49226ea8 powerpc/watchdog: provide more data in watchdog messages
Provide timebase and timebase of last heartbeat in watchdog lockup
messages. Also provide a stack trace of when a CPU becomes un-stuck,
which can be useful -- it could be where irqs are re-enabled, so it
may be the end of the critical section which is responsible for the
latency which is useful information.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:11 +10:00
Nicholas Piggin
5a951c4e7e powerpc/watchdog: don't update the watchdog timestamp if a lockup is detected
The watchdog heartbeat timestamp is updated when the local heartbeat
timer fires (or touch_nmi_watchdog() is called).

This is an interesting data point, so don't overwrite it when the
soft-NMI interrupt detects a hard lockup. That code came from a pre-
merge version to prevent hard lockup messages flood, but that's taken
care of with the stuck CPU logic now, so there is no reason to
update the heartbeat timestamp here.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:11 +10:00
Cédric Le Goater
d2b04b0c78 powerpc/64/kexec: fix race in kexec when XIVE is shutdown
The kexec_state KEXEC_STATE_IRQS_OFF barrier is reached by all
secondary CPUs before the kexec_cpu_down() operation is called on
secondaries. This can raise conflicts and provoque errors in the XIVE
hcalls when XIVE is shutdown with H_INT_RESET on the primary CPU.

To synchronize the kexec_cpu_down() operations and make sure the
secondaries have completed their task before the primary starts doing
the same, let's move the primary kexec_cpu_down() after the
KEXEC_STATE_REAL_MODE barrier.

This change of the ending sequence of kexec is mostly useful on the
pseries platform but it impacts also the powernv, ps3 and 85xx
platforms. powernv can be easily tested and fixed but some caution is
required for the other two.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:08 +10:00
Wolfram Sang
7c18659dd4 powerpc/watchdog: fix typo 'can by' to 'can be'
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:05 +10:00
Christoph Hellwig
15b28bbcd5 dma-debug: move initialization to common code
Most mainstream architectures are using 65536 entries, so lets stick to
that.  If someone is really desperate to override it that can still be
done through <asm/dma-mapping.h>, but I'd rather see a really good
rationale for that.

dma_debug_init is now called as a core_initcall, which for many
architectures means much earlier, and provides dma-debug functionality
earlier in the boot process.  This should be safe as it only relies
on the memory allocator already being available.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2018-05-08 13:02:42 +02:00
Mahesh Salgaonkar
722cde76d6 powerpc/fadump: Unregister fadump on kexec down path.
Unregister fadump on kexec down path otherwise the fadump registration
in new kexec-ed kernel complains that fadump is already registered.
This makes new kernel to continue using fadump registered by previous
kernel which may lead to invalid vmcore generation. Hence this patch
fixes this issue by un-registering fadump in fadump_cleanup() which is
called during kexec path so that new kernel can register fadump with
new valid values.

Fixes: b500afff11f6 ("fadump: Invalidate registration and release reserved memory for general use.")
Cc: stable@vger.kernel.org # v3.4+
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 23:19:30 +10:00
Hari Bathini
8597538712 powerpc/fadump: Do not use hugepages when fadump is active
FADump capture kernel boots in restricted memory environment preserving
the context of previous kernel to save vmcore. Supporting hugepages in
such environment makes things unnecessarily complicated, as hugepages
need memory set aside for them. This means most of the capture kernel's
memory is used in supporting hugepages. In most cases, this results in
out-of-memory issues while booting FADump capture kernel. But hugepages
are not of much use in capture kernel whose only job is to save vmcore.
So, disabling hugepages support, when fadump is active, is a reliable
solution for the out of memory issues. Introducing a flag variable to
disable HugeTLB support when fadump is active.

Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 23:09:25 +10:00
Mahesh Salgaonkar
b71a693d3d powerpc/fadump: exclude memory holes while reserving memory in second kernel
The second kernel, during early boot after the crash, reserves rest of
the memory above boot memory size to make sure it does not touch any of the
dump memory area. It uses memblock_reserve() that reserves the specified
memory region irrespective of memory holes present within that region.
There are chances where previous kernel would have hot removed some of
its memory leaving memory holes behind. In such cases fadump kernel reports
incorrect number of reserved pages through arch_reserved_kernel_pages()
hook causing kernel to hang or panic.

Fix this by excluding memory holes while reserving rest of the memory
above boot memory size during second kernel boot after crash.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 23:09:24 +10:00
Michael Ellerman
0c0c52306f powerpc: Only support DYNAMIC_FTRACE not static
We've had dynamic ftrace support for over 9 years since Steve first
wrote it, all the distros use dynamic, and static is basically
untested these days, so drop support for static ftrace.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:29 +10:00
Naveen N. Rao
ae30cc05be powerpc64/ftrace: Implement support for ftrace_regs_caller()
With -mprofile-kernel, we always save the full register state in
ftrace_caller(). While this works, this is inefficient if we're not
interested in the register state, such as when we're using the function
tracer.

Rename the existing ftrace_caller() as ftrace_regs_caller() and provide
a simpler implementation for ftrace_caller() that is used when registers
are not required to be saved.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:29 +10:00
Naveen N. Rao
9ef4042364 powerpc64/ftrace: Use the generic version of ftrace_replace_code()
Our implementation matches that of the generic version, which also
handles FTRACE_UPDATE_MODIFY_CALL. So, remove our implementation in
favor of the generic version.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:28 +10:00
Naveen N. Rao
250122baed powerpc64/module: Tighten detection of mcount call sites with -mprofile-kernel
For R_PPC64_REL24 relocations, we suppress emitting instructions for TOC
load/restore in the relocation stub if the relocation is for _mcount()
call when using -mprofile-kernel ABI.

To detect this, we check if the preceding instructions are per the
standard set of instructions emitted by gcc: either the two instruction
sequence of 'mflr r0; std r0,16(r1)', or the more optimized variant of a
single 'mflr r0'. This is not sufficient since nothing prevents users
from hand coding sequences involving a 'mflr r0' followed by a 'bl'.

For removing the toc save instruction from the stub, we additionally
check if the symbol is "_mcount". Add the same check here as well.

Also rename is_early_mcount_callsite() to is_mprofile_mcount_callsite()
since that is what is being checked. The use of "early" is misleading
since there is nothing involving this function that qualifies as early.

Fixes: 153086644fd1f ("powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:28 +10:00
Naveen N. Rao
88b1a8547f powerpc64/kexec: Hard disable ftrace before switching to the new kernel
If function_graph tracer is enabled during kexec, we see the below
exception in the simulator:
	root@(none):/# kexec -e
	kvm: exiting hardware virtualization
	kexec_core: Starting new kernel
	[   19.262020070,5] OPAL: Switch to big-endian OS
	kexec: Starting switchover sequence.
	Interrupt to 0xC000000000004380 from 0xC000000000004380
	** Execution stopped: Continuous Interrupt, Instruction caused exception,  **

Now that we have a more effective way to completely disable ftrace on
ppc64, let's also use that before switching to a new kernel during
kexec.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:27 +10:00
Naveen N. Rao
424ef0160f powerpc64/ftrace: Disable ftrace during hotplug
Disable ftrace when a cpu is about to go offline. When the cpu is woken
up, ftrace will get enabled in start_secondary().

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:27 +10:00
Naveen N. Rao
d103978636 powerpc64/ftrace: Delay enabling ftrace on secondary cpus
On the boot cpu, though we enable paca->ftrace_enabled in early_setup()
(via cpu_ready_for_interrupts()), we don't start tracing until much
later since ftrace is not initialized yet and since we only support
DYNAMIC_FTRACE on powerpc. However, it is possible that ftrace has been
initialized by the time some of the secondary cpus start up. In this
case, we will try to trace some of the early boot code which can cause
problems.

To address this, move setting paca->ftrace_enabled from
cpu_ready_for_interrupts() to early_setup() for the boot cpu, and towards
the end of start_secondary() for secondary cpus.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:26 +10:00
Naveen N. Rao
ea678ac627 powerpc64/ftrace: Add a field in paca to disable ftrace in unsafe code paths
We have some C code that we call into from real mode where we cannot
take any exceptions. Though the C functions themselves are mostly safe,
if these functions are traced, there is a possibility that we may take
an exception. For instance, in certain conditions, the ftrace code uses
WARN(), which uses a 'trap' to do its job.

For such scenarios, introduce a new field in paca 'ftrace_enabled',
which is checked on ftrace entry before continuing. This field can then
be set to zero to disable/pause ftrace, and set to a non-zero value to
resume ftrace.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:25 +10:00
Thomas Gleixner
604a98f1df Merge branch 'timers/urgent' into timers/core
Pick up urgent fixes to apply dependent cleanup patch
2018-05-02 16:11:12 +02:00
Nicholas Piggin
6029755eed powerpc: Fix deadlock with multiple calls to smp_send_stop
smp_send_stop can lock up the IPI path for any subsequent calls,
because the receiving CPUs spin in their handler function. This
started becoming a problem with the addition of an smp_send_stop
call in the reboot path, because panics can reboot after doing
their own smp_send_stop.

The NMI IPI variant was fixed with ac61c11566 ("powerpc: Fix
smp_send_stop NMI IPI handling"), which leaves the smp_call_function
variant.

This is fixed by having smp_send_stop only ever do the
smp_call_function once. This is a bit less robust than the NMI IPI
fix, because any other call to smp_call_function after smp_send_stop
could deadlock, but that has always been the case, and it was not
been a problem before.

Fixes: f2748bdfe1573 ("powerpc/powernv: Always stop secondaries before reboot/shutdown")
Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-27 16:35:57 +10:00
Eric W. Biederman
e821fa4245 signal/powerpc: Replace TRAP_FIXME with TRAP_UNK
Using an si_code of 0 that aliases with SI_USER is clearly the wrong
thing todo, and causes problems in interesting ways.

For use in unknown_exception the recently defined TRAP_UNK
semantically is a perfect fit.  For use in RunModeException it looks
like something more specific than TRAP_UNK could be used.  No one has
bothered to find a better fit than the broken si_code of 0 in all of
these years and I don't see an obvious better fit so TRAP_UNK is
switching RunModeException to return TRAP_UNK is clearly an
improvement.

Recent history suggests no actually cares about crazy corner
cases of the kernel behavior like this so I don't expect any
regressions from changing this.  However if something does
happen this change is easy to revert.

Though I wonder if SIGKILL might not be a better fit.

Cc: Paul Mackerras <paulus@samba.org>
Cc: Kumar Gala <kumar.gala@freescale.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Fixes: 9bad068c24d7 ("[PATCH] ppc32: support for e500 and 85xx")
Fixes: 0ed70f6105ef ("PPC32: Provide proper siginfo information on various exceptions.")
History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-25 10:40:58 -05:00
Eric W. Biederman
aeb1c0f6ff signal/powerpc: Replace FPE_FIXME with FPE_FLTUNK
Using an si_code of 0 that aliases with SI_USER is clearly the
wrong thing todo, and causes problems in interesting ways.

The newly defined FPE_FLTUNK semantically appears to fit the
bill so use it instead.

Cc: Paul Mackerras <paulus@samba.org>
Cc: Kumar Gala <kumar.gala@freescale.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc:  linuxppc-dev@lists.ozlabs.org
Fixes: 9bad068c24d7 ("[PATCH] ppc32: support for e500 and 85xx")
Fixes: 0ed70f6105ef ("PPC32: Provide proper siginfo information on various exceptions.")
History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-25 10:40:55 -05:00