Commit Graph

157 Commits

Author SHA1 Message Date
Douglas Miller
5e48dc0aa4 powerpc/xmon: Dump memory in CPU endian format
Extend the dump command to allow display of 2, 4, and 8 byte words in
CPU endian format. Also adds dump command for "1 byte values" for the
sake of symmetry. New commands are:

  d1	dump 1 byte values
  d2	dump 2 byte values
  d4	dump 4 byte values
  d8	dump 8 byte values

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
2017-02-21 16:00:21 +11:00
Balbir Singh
5b102782c7 powerpc/xmon: Enable disassembly files (compilation changes)
After updating ppc-dis.c, ppc-opc.c and ppc.h the following changes were
made to enable compilation and working of xmon:

  1.  Remove all disassembler_info
  2.  Use xmon's printf/print_address to output data and addresses
      respectively.
  3.  All bfd_* types and casts have been removed.
  4.  Optimizations related to opcd_indices have been removed.
  5.  The dialect is set based on cpu features.
  6.  PPC_OPCODE_CLASSIC is no longer supported in the new
      disassembler.
  7.  VLE opcode parsing and printing has been stripped.
  8.  Coding style conventions used for those routines has
      been retained and it does not match our CodingStyle.
  9.  The highest supported dialect is POWER9.
  10. Defined ATTRIBUTE_UNUSED in ppc-dis.c.
  11. Defined _(x) in ppc-dis.c.

Finally, we remove the dependency on BROKEN so that XMON_DISASSEMBLY can
be enabled again.

Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-15 20:02:42 +11:00
Balbir Singh
08d96e0b12 powerpc/xmon: Apply binutils changes to upgrade disassembly
The following commit-ids from the binutils project were applied on the
xmon branch and relicensed with the permission of the authors under
GPLv2 for the following files:

  ppc-opc.c
  ppc-dis.c
  ppc.h

Working off of binutils commit 65b650b4c746 we have now moved up to
binutils commit a5721ba270dd.

Some commit logs have been taken verbatim, some are summarized for ease
of understanding.

Here is a summary of the commits:

 33e8d5ac613d PPC7450 New.  (powerpc_opcodes): Use it in dcba.
 c3d65c1ced61 New opcodes and mask
 8dbcd839b1bb Instruction Sorting
 91eb7075e370 (powerpc_opcodes): Fix the first two operands of dquaiq.
 548b1dcfcbab ppc-opc.c (powerpc_opcodes): Remove the dcffix and dcffix.
 930bb4cfae30 Support optional L form mtmsr.
 de866fccd87d (powerpc_opcodes): Order and format.
 19a6653ce8c6 ppc e500mc support
 fa452fa6833c (ppc_cpu_t): New typedef.
 c8187e1509b2 (parse_cpu): Handle -m464.
 081ba1b3c08b Define. (PPC_OPERAND_FSL, PPC_OPERAND_FCR, PPC_OPERAND_UDI)
 9b4e57660d38 Rename altivec_or_spe to retain_flags. Handle -mvsx and -mpower7.
 899d85beadd0 (powerpc_opcodes): Enable rfci, mfpmr, mtpmr for e300.
 e1c93c699b7d (extract_sprg): Correct operand range check.
 2f3bb96af796 (powerpc_init_dialect): Do not set PPC_OPCODE_BOOKE
 1cb0a7674666 (ppc_setup_opcodes): Remove PPC_OPCODE_NOPOWER4 test
 21169fcfadfa (print_insn_powerpc): Skip insn if it is deprecated
 80890a619b85 ("dcbt", "dcbtst")
 0e55be1624c2 ("lfdepx", "stfdepx")
 066be9f7bd8e (parse_cpu): Extend -mpower7 to accept power7 and isel instructions.
 c72ab5f2c55d (powerpc_opcodes): Reorder the opcode table so that instructions
 69fe9ce501f5 (ppc_parse_cpu): New function. 	(powerpc_init_dialect)
 e401b04ca7cd (powerpc_opcodes) <"dcbzl">: Merge the POWER4 and E500MC entries.
 70dc4e324b9a (powerpc_init_dialect): Do not choose a default dialect due to -many/-Many.
 858d7a6db20b (powerpc_opcodes) <"tlbilxlpid", "tlbilxpid", "tlbilxva", "tlbilx"
 bdc7fcfe59f1 (powerpc_macros <extrdi>): Allow n+b of 64
 e0d602ecffb0 (md_show_usage): Document -mpcca2
 b961e85b6ebe (ppc_cpu_t): Typedef to uint64_t
 8765b5569284 (powerpc_opcodes): Remove support for the the "lxsdux", "lxvd2ux"
 634b50f2a623 Rename "ppca2" to "a2"
 9fe54b1ca1c0 (md_show_usage): Document -m476
 0dc9305793c8 Add bfd_mach_ppc_e500mc64
 ce3d2015b21b Define. bfd/ 	* archures.c (bfd_mach_ppc_titan)
 cdc51b0748c4 Add -mpwr4, -mpwr5, -mpwr5x, -mpwr6 and -mpwr7
 63d0fa4e9e57 Add PPC_OPCODE_E500MC for "e500mc64"
 cee62821d472 New Define. ("dccci"): Enable for PPCA2
 85d4ac0b3c0b Correct wclr encoding.
 51b5d4a8c5e5 (powerpc_opcodes): Enable divdeu, devweu, divde, divwe, divdeuo
 e01d869a3be2 (md_assemble): Emit APUinfo section for PPC_OPCODE_E500
 09a8ad8d8f56 (powerpc_opcodes): Revert deprecation of mfocrf, mtcrf and mtocrf on EFS.
 f2bae120dcef (PPC_OPCODE_COMMON): Expand comment.
 81a0b7e2ae09 (PPCPWR2): Add PPC_OPCODE_COMMON. (powerpc_opcodes): Add "subc"
 bdc70b4a03fd (PPC_OPCODE_32, PPC_OPCODE_BOOKE64, PPC_OPCODE_CLASSIC)
 7102e95e4943 (ppc_set_cpu): Cast PPC_OPCODE_xxx to ppc_cpu_t before inverting
 f383de6633cb (powerpc_opcodes) [lswx,lswi,stswx,stswi]: Deprecate on E500 and E500MC
 6b069ee70de3 Remove PPC_OPCODE_PPCPS
 2f7f77101279 (powerpc_opcodes): Enable icswx for POWER7
 989993d80a97 (insert_nbi, insert_rbx, FRAp, FRBp, FRSp, FRTp, NBI, RAX, RBX)
 a08fc94222d1 <drrndq, drrndq., dtstexq, dctqpq, dctqpq., dctfixq, dctfixq.
 8ebac3aae962 (ISA_V2): Define and use for relevant BO field tests
 aea77599d0db Add PPC_OPCODE_ALTIVEC2, PPC_OPCODE_E6500, PPC_OPCODE_TMR
 b240011aba98 (disassemble_init_for_target): Handle ppc init.
 d668828207c2 (powerpc_opcd_indices): Bump array size
 b9c361e0ad33 Add support for PowerPC VLE.
 e1dad58d73dc (has_tls_reloc, has_tls_get_addr_call, has_vle_insns, is_ppc_vle)
 df7b86aa4cb6 Add check that sysdep.h has been included before
 98c76446ea6b (extract_sprg): Use ALLOW8_SPRG to include VLE.
 a4ebc835cbcb (powerpc_macros): Add entries for e_extlwi to e_clrlslwi
 94caa966375d (has_vle_insns, is_ppc_vle): Delete
 c7a8dbf91f37 Change RA to RA0
 d908c8af5a1d Add necessary casts for printing integer values
 03edbe3bfb93 Add/remove PPCVLE for some 32-bit insns
 9f6a6cc022e1 <xnop, yield, mdoio, mdoom>: New extended mnemonics
 588925d06545 <RSQ, RTQ>: Use PPC_OPERAND_GPR
 8baf7b78b5d9 <"lswx">: Use RAX for the second and RBX for the third operand
 e67ed0e885d6 Changed opcode for vabsdub, vabsduh, vabsduw, mviwsplt
 fb048c26f19f (UIMM4, UIMM3, UIMM2, VXVA_MASK, VXVB_MASK, VXVAVB_MASK, VXVDVA_MASK
 382c72e90441 (VXASHB_MASK): New define
 c7a5aa9c64fc (ppc_opts) <altivec>: Use PPC_OPCODE_ALTIVEC2
 ab4437c3224f <vcfpsxws>: Fix opcode spelling
 62082a42b9cd "lfdp" and "stfdp" use DS offset.
 776fc41826bb (ppc_parse_cpu): Update prototype
 943d398f4c52 (insert_sci8, extract_sci8): Rewrite.
 5817ffd1f81c New define (PPC_OPCODE_HTM/POWER8)
 9f0682fe89d9 (extract_vlesi): Properly sign extend
 c0637f3af686 (powerpc_init_dialect): Set default dialect to power8.
 58ae08f29af8 (powerpc_opcodes): Add tdui, twui, tdu, twu, tui, tu
 4f6ffcd38d90 (powerpc_init_dialect): Use ppc_parse_cpu() to set dialect
 4b95cf5c0c75 Update copyright years
 a47622ac1bad Allow both signed and unsigned fields in PowerPC cmpli insn
 12e87fac5c76 ppc: enable msgclr and msgsnd on Power8
 8514e4db84cc Don't deprecate powerpc mftb insn
 db76a70026ab Power4 should treat mftb as extended mfspr mnemonic
 b90efa5b79ac ChangeLog rotatation and copyright year update
 c4e676f19656 powerpc: Add slbfee. instruction
 27c49e9a8fc0 powerpc: Only initialise opcode indices once
 4fff86c517ab DCBT_EO): New define
 4bc0608a8b69 Fix some PPC assembler errors
 dc302c00611b Add hwsync extended mnemonic
 99a2c5612124 Remove unused MTMSRD_L macro and re-add accidentally deleted comment
 11a0cf2ec0ed Allow for optional operands with non-zero default values
 7b9341139a69 PPC sync instruction accepts invalid and incompatible operands
 ef5a96d564a2 Remove ppc860, ppc750cl, ppc7450 insns from common ppc
 43e65147c07b Remove trailing spaces in opcodes
 6dca4fd141fd Add dscr and ctrl SPR mnemonics
 b6518b387185 Fix compile time warnings generated when compiling with clang
 36f7a9411dcd Patches for illegal ppc 500 instructions
 a680de9a980e Add assembler, disassembler and linker support for power9
 dd2887fc3de4 Reorder some power9 insns
 b817670b52b7 Enable 2 operand form of powerpc mfcr with -many
 6f2750feaf28 Copyright update for binutils
 afa8d4054b8e Delete opcodes that have been removed from ISA 3.0
 1178da445ad5 Accept valid one byte signed and unsigned values for the IMM8 operand
 e43de63c8fd1 Fix powerpc subis range
 514e58b72633 Correct "Fix powerpc subis range"
 19dfcc89e8d9 Add support for new POWER ISA 3.0 instructions
 1fe0971e41a4 add more extern C
 026122a67044 Re-add support for lbarx, lharx, stbcx. and sthcx. insns back to the E6500 cpu
 14b57c7c6a53 PowerPC VLE
 6fd3a02da554 Add support for yet some more new ISA 3.0 instructions
 dfdaec14b0db Fix some PowerPC VLE BFD issues and add some PowerPC VLE instructions
 fd486b633e87 Modify POWER9 support to match final ISA 3.0 documentation
 a5721ba270dd Disallow 3-operand cmp[l][i] for ppc64

This updates the disassembly capabilities to add support for newer
processors.

Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Reformat commit list for brevity]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-15 20:02:42 +11:00
Balbir Singh
cc7639ce18 powerpc/xmon: Update ppc-dis/opc.c and ppc.h
Upgrade ppc-opc.c, ppc-dis.c and ppc.h to the versions belonging to the
following binutils commit:

  65b650b4c7463f4508bed523c24ab0031a5ae5cd
  * ppc-dis.c (print_insn_powerpc): Don't skip all operands after
    setting skip_optional.

That is the last version of those files that were licensed under GPLv2.

This leaves the code in a state that does not compile, because the
binutils code needs to be tweaked to work in the kernel. We don't fix
that in this commit, because we want to import more binutils changes in
subsequent commits. So for now we mark XMON_DISASSEMBLY as BROKEN, so it
can't be built.

Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-15 20:02:41 +11:00
Madhavan Srinivasan
e71ff89c71 powerpc/xmon: Cleanup to use is_kernel_addr macro
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-02 16:44:14 +11:00
Michael Ellerman
56144ec7c9 powerpc/xmon: Add 'dt' command to dump trace buffers
There is a nice interface for asking ftrace to dump all its tracing
buffers. The only down side for use in xmon is that it uses printk.
Depending on circumstances printk may not work when in xmon, but it also
may, so add a 'dt' command which dumps the ftrace buffers, and add a
note to the help to mentiont that it uses printk.

Calling this routine also disables tracing, which is problematic if you
return from xmon and expect the system to keep operating normally. So
after we do the dump turn tracing back on.

Both functions already have nop versions defined for when ftrace is not
enabled, so we don't need any extra #ifdefs.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-25 14:30:27 +11:00
Michael Ellerman
b42d9023a3 powerpc/xmon: Don't use ld on 32-bit
In commit 31cdd0c39c ("powerpc/xmon: Fix SPR read/write commands and
add command to dump SPRs") I added two uses of the "ld" instruction in
spr_access.S. "ld" is a 64-bit instruction, so shouldn't be used on
32-bit CPUs.

Replace it with PPC_LL which is a macro that gives us either "ld" or
"lwz" depending on whether we're 64 or 32-bit.

Fixes: 31cdd0c39c ("powerpc/xmon: Fix SPR read/write commands and add command to dump SPRs")
Cc: stable@vger.kernel.org # v4.7+
Reported-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-13 17:37:02 +10:00
Kevin Hao
b92a226e52 powerpc: Move cpu_has_feature() to a separate file
We plan to use jump label for cpu_has_feature(). In order to implement
this we need to include the linux/jump_label.h in asm/cputable.h.

Unfortunately if we do that it leads to an include loop. The root of the
problem seems to be that reg.h needs cputable.h (for CPU_FTRs), and then
cputable.h via jump_label.h eventually pulls in hw_irq.h which needs
reg.h (for MSR_EE).

So move cpu_has_feature() to a separate file on its own.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[mpe: Rename to cpu_has_feature.h and flesh out change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-01 11:15:03 +10:00
Michael Ellerman
719dbb2df7 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/scottwood/linux into next
Freescale updates from Scott:

"Highlights include more 8xx optimizations, device tree updates,
and MVME7100 support."
2016-07-30 13:43:19 +10:00
Michael Ellerman
e0ddf7a245 powerpc/xmon: Dump ISA 2.07 SPRs
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-14 20:26:24 +10:00
Michael Ellerman
1846193b17 powerpc/xmon: Dump ISA 2.06 SPRs
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-14 20:26:24 +10:00
Michael Ellerman
56346ad88d powerpc/xmon: Adjust spacing of existing SPRs to make room for more
Purely to make it pleasing to the eye.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-14 20:26:23 +10:00
Michael Ellerman
13629dad1e powerpc/xmon: Move static regno into its only user
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-14 20:26:23 +10:00
Michael Ellerman
5b71eff782 powerpc/xmon: Remove unused externs
None of these are used, or have been since we merged ppc & ppc64.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-14 20:26:22 +10:00
Christophe Leroy
c223c90386 powerpc32: provide VIRT_CPU_ACCOUNTING
This patch provides VIRT_CPU_ACCOUTING to PPC32 architecture.
PPC32 doesn't have the PACA structure, so we use the task_info
structure to store the accounting data.

In order to reuse on PPC32 the PPC64 functions, all u64 data has
been replaced by 'unsigned long' so that it is u32 on PPC32 and
u64 on PPC64

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
2016-07-09 01:43:50 -05:00
Paul Mackerras
31cdd0c39c powerpc/xmon: Fix SPR read/write commands and add command to dump SPRs
xmon has commands for reading and writing SPRs, but they don't work
currently for several reasons. They attempt to synthesize a small
function containing an mfspr or mtspr instruction and call it. However,
the instructions are on the stack, which is usually not executable.
Also, for 64-bit we set up a procedure descriptor, which is fine for the
big-endian ABIv1, but not correct for ABIv2. Finally, the code uses the
infrastructure for catching memory errors, but that only catches data
storage interrupts and machine check interrupts, but a failed
mfspr/mtspr can generate a program interrupt or a hypervisor emulation
assist interrupt, or be a no-op.

Instead of trying to synthesize a function on the fly, this adds two new
functions, xmon_mfspr() and xmon_mtspr(), which take an SPR number as an
argument and read or write the SPR. Because there is no Power ISA
instruction which takes an SPR number in a register, we have to generate
one of each possible mfspr and mtspr instruction, for all 1024 possible
SPRs. Thus we get just over 8k bytes of code for each of xmon_mfspr()
and xmon_mtspr(). However, this 16kB of code pales in comparison to the
> 130kB of PPC opcode tables used by the xmon disassembler.

To catch interrupts caused by the mfspr/mtspr instructions, we add a new
'catch_spr_faults' flag. If an interrupt occurs while it is set, we come
back into xmon() via program_check_interrupt(), _exception() and die(),
see that catch_spr_faults is set and do a longjmp to bus_error_jmp, back
into read_spr() or write_spr().

This adds a couple of other nice features: first, a "Sa" command that
attempts to read and print out the value of all 1024 SPRs. If any mfspr
instruction acts as a no-op, then the SPR is not implemented and not
printed.

Secondly, the Sr and Sw commands detect when an SPR is not
implemented (i.e. mfspr is a no-op) and print a message to that effect
rather than printing a bogus value.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-11 21:54:07 +10:00
Aneesh Kumar K.V
caca285e5a powerpc/mm/radix: Use STD_MMU_64 to properly isolate hash related code
We also use MMU_FTR_RADIX to branch out from code path specific to
hash.

No functionality change.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-11 21:53:45 +10:00
Douglas Miller
6dfb54049f powerpc/xmon: Add xmon command to dump process/task similar to ps(1)
Add 'P' command with optional task_struct address to dump all/one task's
information: task pointer, kernel stack pointer, PID, PPID, state
(interpreted), CPU where (last) running, and command.

Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-10 10:22:04 +11:00
Andrew Donnellan
fde93a0f77 powerpc/xmon: add command to dump OPAL msglog
Add the 'do' command to dump the OPAL msglog in xmon.

Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
[mpe: Reduce the amount of ifdefery required]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-09 21:03:39 +11:00
Andrew Donnellan
2e34057929 powerpc/xmon: fix typo in usage message
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-08 22:34:52 +11:00
Daniel Axtens
bf76f73c5f powerpc: enable UBSAN support
This hooks up UBSAN support for PowerPC.

So far it's found some interesting cases where we don't properly sanitise
input to shifts, including one in our futex handling.  Nothing critical,
but interesting and worth fixing.

[valentinrothberg@gmail.com: arch/powerpc/Kconfig: fix typo in select statement]
Signed-off-by: Daniel Axtens <dja@axtens.net>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20 17:09:18 -08:00
Michael Ellerman
08eb105a7c powerpc/xmon: Use rtas_call_unlocked() in xmon
Avoid open coding the logic by using rtas_call_unlocked().

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-17 22:40:55 +11:00
Rashmica Gupta
eb925d6460 powerpc/xmon: Append linux_banner to exception information in xmon.
Currently if you are in xmon without an oops etc. to view the kernel
version you have to type "d $linux_banner" - not necessarily obvious. As
this is useful information, append to the output of "e" command.

Example output:
  $mon> e
  cpu 0x1: Vector: 0  at [c0000000f879ba80]
      pc: c000000000081718: sysrq_handle_xmon+0x68/0x80
      lr: c000000000081718: sysrq_handle_xmon+0x68/0x80
      sp: c0000000f879bbe0
     msr: 8000000000009033
    current = 0xc0000000f604d5c0
    paca    = 0xc00000000fdc0480	 softe: 0	 irq_happened: 0x01
      pid   = 2467, comm = bash
  Linux version 4.4.0-rc2-00008-gc51af91c3ab3-dirty (rashmica@circle) (gcc
  version 5.1.1 20150629 (GCC) ) #45 SMP Wed Nov 25 10:25:12 AEDT 2015

Signed-off-by: Rashmica Gupta <rashmicy@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-14 20:41:50 +11:00
Michael Ellerman
ad987fc8ea powerpc/xmon: Add some more elements to the existing PACA dump list
This patch adds a set of new elements to the existing PACA dump list
inside an xmon session which can be listed below improving the overall
xmon debug support.

With this patch, a typical xmon PACA dump looks something like this.

paca for cpu 0x0 @ c00000000fdc0000:
 possible             = yes
 present              = yes
 online               = yes
 lock_token           = 0x8000            	(0xa)
 paca_index           = 0x0               	(0x8)
 kernel_toc           = 0xc000000001393200	(0x10)
 kernelbase           = 0xc000000000000000	(0x18)
 kernel_msr           = 0xb000000000001033	(0x20)
 emergency_sp         = 0xc00000003fff0000	(0x28)
 mc_emergency_sp      = 0xc00000003ffec000	(0x2e0)
 in_mce               = 0x0               	(0x2e8)
 hmi_event_available  = 0x0               	(0x2ea)
 data_offset          = 0x1fe7b0000       	(0x30)
 hw_cpu_id            = 0x0               	(0x38)
 cpu_start            = 0x1               	(0x3a)
 kexec_state          = 0x0               	(0x3b)
 slb_shadow[0]:       = 0xc000000008000000 0x40016e7779000510
 slb_shadow[1]:       = 0xd000000008000001 0x400142add1000510
 vmalloc_sllp         = 0x510             	(0x1b8)
 slb_cache_ptr        = 0x4               	(0x1ba)
 slb_cache[0]:        = 0x000000000003f000
 slb_cache[1]:        = 0x0000000000000001
 slb_cache[2]:        = 0x0000000000000003
 slb_cache[3]:        = 0x0000000000001000
 slb_cache[4]:        = 0x0000000000001000
 slb_cache[5]:        = 0x0000000000000000
 slb_cache[6]:        = 0x0000000000000000
 slb_cache[7]:        = 0x0000000000000000
 dscr_default         = 0x0               	(0x58)
 __current            = 0xc000000001331e80	(0x290)
 kstack               = 0xc000000001393e30	(0x298)
 stab_rr              = 0x11              	(0x2a0)
 saved_r1             = 0xc0000001fffef5e0	(0x2a8)
 trap_save            = 0x0               	(0x2b8)
 soft_enabled         = 0x0               	(0x2ba)
 irq_happened         = 0x1               	(0x2bb)
 io_sync              = 0x0               	(0x2bc)
 irq_work_pending     = 0x0               	(0x2bd)
 nap_state_lost       = 0x0               	(0x2be)
 sprg_vdso            = 0x0               	(0x2c0)
 tm_scratch           = 0x8000000100009033	(0x2c8)
 core_idle_state_ptr  = (null)            	(0x2d0)
 thread_idle_state    = 0x0               	(0x2d8)
 thread_mask          = 0x0               	(0x2d9)
 subcore_sibling_mask = 0x0               	(0x2da)
 user_time            = 0x0               	(0x2f0)
 system_time          = 0x0               	(0x2f8)
 user_time_scaled     = 0x0               	(0x300)
 starttime            = 0x3f462418b5cf4   	(0x308)
 starttime_user       = 0x3f4622a57092a   	(0x310)
 startspurr           = 0xd62a5718        	(0x318)
 utime_sspurr         = 0x0               	(0x320)
 stolen_time          = 0x0               	(0x328)

Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
[mpe: Endian swap slb_shadow before display, minor formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-15 20:32:02 +11:00
Sam bobroff
0c23a88ccc powerpc/xmon: Paginate kernel log buffer display
The kernel log buffer is often much longer than the size of a terminal
so paginate it's output.

Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-15 20:32:02 +11:00
Sam bobroff
958b7c8050 powerpc/xmon: Paged output for paca display
The paca display is already more than 24 lines, which can be problematic
if you have an old school 80x24 terminal, or more likely you are on a
virtual terminal which does not scroll for whatever reason.

This patch adds a new command "#", which takes a single (hex) numeric
argument: lines per page. It will cause the output of "dp" and "dpa"
to be broken into pages, if necessary.

Sample output:

0:mon> # 10
0:mon> dp1
paca for cpu 0x1 @ c00000000fdc0480:
 possible         = yes
 present          = yes
 online           = yes
 lock_token       = 0x8000            	(0x8)
 paca_index       = 0x1               	(0xa)
 kernel_toc       = 0xc000000000eb2400	(0x10)
 kernelbase       = 0xc000000000000000	(0x18)
 kernel_msr       = 0xb000000000001032	(0x20)
 emergency_sp     = 0xc00000003ffe8000	(0x28)
 mc_emergency_sp  = 0xc00000003ffe4000	(0x2e0)
 in_mce           = 0x0               	(0x2e8)
 data_offset      = 0x7f170000        	(0x30)
 hw_cpu_id        = 0x8               	(0x38)
 cpu_start        = 0x1               	(0x3a)
 kexec_state      = 0x0               	(0x3b)
[Hit a key (a:all, q:truncate, any:next page)]
0:mon>
 __current        = 0xc00000007e696620	(0x290)
 kstack           = 0xc00000007e6ebe30	(0x298)
 stab_rr          = 0xb               	(0x2a0)
 saved_r1         = 0xc00000007ef37860	(0x2a8)
 trap_save        = 0x0               	(0x2b8)
 soft_enabled     = 0x0               	(0x2ba)
 irq_happened     = 0x1               	(0x2bb)
 io_sync          = 0x0               	(0x2bc)
 irq_work_pending = 0x0               	(0x2bd)
 nap_state_lost   = 0x0               	(0x2be)
0:mon>

Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
[mpe: Use bool, make some variables static]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-15 20:32:01 +11:00
Anshuman Khandual
8218a3031c powerpc/xmon: Drop the valid variable completely in dump_segments()
The value of 'valid' is always zero when 'esid' is zero, and if 'esid'
is non-zero then the value of 'valid' is irrelevant because we are using
logical or in the if expression.

In fact 'valid' can be dropped completely from dump_segments() by
simply doing the check with SLB_ESID_V directly in the if.

Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
[mpe: Rewrite change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-08-12 15:05:47 +10:00
Joe Perches
a825ac078b powerpc: Remove redundant breaks
break; break; isn't useful.

Remove one.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-08-06 15:10:20 +10:00
Linus Torvalds
d3f180ea1a powerpc updates for 3.20
Including:
 
 - Update of all defconfigs
 - Addition of a bunch of config options to modernise our defconfigs
 - Some PS3 updates from Geoff
 - Optimised memcmp for 64 bit from Anton
 - Fix for kprobes that allows 'perf probe' to work from Naveen
 - Several cxl updates from Ian & Ryan
 - Expanded support for the '24x7' PMU from Cody & Sukadev
 - Freescale updates from Scott:
   "Highlights include 8xx optimizations, some more work on datapath device
    tree content, e300 machine check support, t1040 corenet error reporting,
    and various cleanups and fixes."
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Merge tag 'powerpc-3.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux

Pull powerpc updates from Michael Ellerman:

 - Update of all defconfigs

 - Addition of a bunch of config options to modernise our defconfigs

 - Some PS3 updates from Geoff

 - Optimised memcmp for 64 bit from Anton

 - Fix for kprobes that allows 'perf probe' to work from Naveen

 - Several cxl updates from Ian & Ryan

 - Expanded support for the '24x7' PMU from Cody & Sukadev

 - Freescale updates from Scott:
    "Highlights include 8xx optimizations, some more work on datapath
     device tree content, e300 machine check support, t1040 corenet
     error reporting, and various cleanups and fixes"

* tag 'powerpc-3.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (102 commits)
  cxl: Add missing return statement after handling AFU errror
  cxl: Fail AFU initialisation if an invalid configuration record is found
  cxl: Export optional AFU configuration record in sysfs
  powerpc/mm: Warn on flushing tlb page in kernel context
  powerpc/powernv: Add OPAL soft-poweroff routine
  powerpc/perf/hv-24x7: Document sysfs event description entries
  powerpc/perf/hv-gpci: add the remaining gpci requests
  powerpc/perf/{hv-gpci, hv-common}: generate requests with counters annotated
  powerpc/perf/hv-24x7: parse catalog and populate sysfs with events
  perf: define EVENT_DEFINE_RANGE_FORMAT_LITE helper
  perf: add PMU_EVENT_ATTR_STRING() helper
  perf: provide sysfs_show for struct perf_pmu_events_attr
  powerpc/kernel: Avoid initializing device-tree pointer twice
  powerpc: Remove old compile time disabled syscall tracing code
  powerpc/kernel: Make syscall_exit a local label
  cxl: Fix device_node reference counting
  powerpc/mm: bail out early when flushing TLB page
  powerpc: defconfigs: add MTD_SPI_NOR (new dependency for M25P80)
  perf/powerpc: reset event hw state when adding it to the PMU
  powerpc/qe: Use strlcpy()
  ...
2015-02-11 18:15:38 -08:00
Laurent Dufour
e6eb2eba49 powerpc/xmon: Fix another endiannes issue in RTAS call from xmon
The commit 3b8a3c0109 ("powerpc/pseries: Fix endiannes issue in RTAS
call from xmon") was fixing an endianness issue in the call made from
xmon to RTAS.

However, as Michael Ellerman noticed, this fix was not complete, the
token value was not byte swapped. This lead to call an unexpected and
most of the time unexisting RTAS function, which is silently ignored by
RTAS.

This fix addresses this hole.

Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: stable@vger.kernel.org
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-01-19 09:58:16 +11:00
Vincent Bernat
05b981f493 powerpc/xmon: use isspace/isxdigit/isalnum from linux/ctype.h
isxdigit() macro definition is the same.

isalnum() from linux/ctype.h will accept additional latin non-ASCII
characters. This is harmless since this macro is used in scanhex() which
parses user input.

isspace() from linux/ctype.h will accept vertical tab and form feed but
not NULL. The use of this macro is modified to accept NULL as
well. Additional characters are harmless since this macro is also only
used in scanhex().

Signed-off-by: Vincent Bernat <vincent@bernat.im>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-12-29 15:45:43 +11:00
Linus Torvalds
140cd7fb04 powerpc updates for 3.19
Some nice cleanups like removing bootmem, and removal of __get_cpu_var().
 
 There is one patch to mm/gup.c. This is the generic GUP implementation, but is
 only used by us and arm(64). We have an ack from Steve Capper, and although we
 didn't get an ack from Andrew he told us to take the patch through the powerpc
 tree.
 
 There's one cxl patch. This is in drivers/misc, but Greg said he was happy for
 us to manage fixes for it.
 
 There is an infrastructure patch to support an IPMI driver for OPAL. That patch
 also appears in Corey Minyard's IPMI tree, you may see a conflict there.
 
 There is also an RTC driver for OPAL. We weren't able to get any response from
 the RTC maintainer, Alessandro Zummo, so in the end we just merged the driver.
 
 The usual batch of Freescale updates from Scott.
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Merge tag 'powerpc-3.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux

Pull powerpc updates from Michael Ellerman:
 "Some nice cleanups like removing bootmem, and removal of
  __get_cpu_var().

  There is one patch to mm/gup.c.  This is the generic GUP
  implementation, but is only used by us and arm(64).  We have an ack
  from Steve Capper, and although we didn't get an ack from Andrew he
  told us to take the patch through the powerpc tree.

  There's one cxl patch.  This is in drivers/misc, but Greg said he was
  happy for us to manage fixes for it.

  There is an infrastructure patch to support an IPMI driver for OPAL.

  There is also an RTC driver for OPAL.  We weren't able to get any
  response from the RTC maintainer, Alessandro Zummo, so in the end we
  just merged the driver.

  The usual batch of Freescale updates from Scott"

* tag 'powerpc-3.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (101 commits)
  powerpc/powernv: Return to cpu offline loop when finished in KVM guest
  powerpc/book3s: Fix partial invalidation of TLBs in MCE code.
  powerpc/mm: don't do tlbie for updatepp request with NO HPTE fault
  powerpc/xmon: Cleanup the breakpoint flags
  powerpc/xmon: Enable HW instruction breakpoint on POWER8
  powerpc/mm/thp: Use tlbiel if possible
  powerpc/mm/thp: Remove code duplication
  powerpc/mm/hugetlb: Sanity check gigantic hugepage count
  powerpc/oprofile: Disable pagefaults during user stack read
  powerpc/mm: Check for matching hpte without taking hpte lock
  powerpc: Drop useless warning in eeh_init()
  powerpc/powernv: Cleanup unused MCE definitions/declarations.
  powerpc/eeh: Dump PHB diag-data early
  powerpc/eeh: Recover EEH error on ownership change for BCM5719
  powerpc/eeh: Set EEH_PE_RESET on PE reset
  powerpc/eeh: Refactor eeh_reset_pe()
  powerpc: Remove more traces of bootmem
  powerpc/pseries: Initialise nvram_pstore_info's buf_lock
  cxl: Name interrupts in /proc/interrupt
  cxl: Return error to PSL if IRQ demultiplexing fails & print clearer warning
  ...
2014-12-11 17:48:14 -08:00
Michael Ellerman
abb90ee7bc powerpc/xmon: Cleanup the breakpoint flags
Drop BP_IABR_TE, which though used, does not do anything useful. Rename
BP_IABR to BP_CIABR. Renumber the flags.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-12-02 14:23:04 +11:00
Anshuman Khandual
1ad7d70562 powerpc/xmon: Enable HW instruction breakpoint on POWER8
This patch enables support for hardware instruction breakpoint in xmon
on POWER8 platform with the help of a new register called the CIABR
(Completed Instruction Address Breakpoint Register). With this patch, a
single hardware instruction breakpoint can be added and cleared during
any active xmon debug session. The hardware based instruction breakpoint
mechanism works correctly with the existing TRAP based instruction
breakpoint available on xmon.

There are no powerpc CPU with CPU_FTR_IABR feature any more. This patch
has re-purposed all the existing IABR related code to work with CIABR
register based HW instruction breakpoint.

This has one odd feature, which is that when we hit a breakpoint xmon
doesn't tell us we have hit the breakpoint. This is because xmon is
expecting bp->address == regs->nip. Because CIABR fires on completition
regs->nip points to the instruction after the breakpoint. We could fix
that, but it would then confuse other parts of the xmon code which think
we need to emulate the instruction. [mpe]

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
2014-12-02 14:23:04 +11:00
Laurent Dufour
3b8a3c0109 powerpc/pseries: Fix endiannes issue in RTAS call from xmon
On pseries system (LPAR) xmon failed to enter when running in LE mode,
system is hunging. Inititating xmon will lead to such an output on the
console:

SysRq : Entering xmon
cpu 0x15: Vector: 0  at [c0000003f39ffb10]
    pc: c00000000007ed7c: sysrq_handle_xmon+0x5c/0x70
    lr: c00000000007ed7c: sysrq_handle_xmon+0x5c/0x70
    sp: c0000003f39ffc70
   msr: 8000000000009033
  current = 0xc0000003fafa7180
  paca    = 0xc000000007d75e80	 softe: 0	 irq_happened: 0x01
    pid   = 14617, comm = bash
Bad kernel stack pointer fafb4b0 at eca7cc4
cpu 0x15: Vector: 300 (Data Access) at [c000000007f07d40]
    pc: 000000000eca7cc4
    lr: 000000000eca7c44
    sp: fafb4b0
   msr: 8000000000001000
   dar: 10000000
 dsisr: 42000000
  current = 0xc0000003fafa7180
  paca    = 0xc000000007d75e80	 softe: 0	 irq_happened: 0x01
    pid   = 14617, comm = bash
cpu 0x15: Exception 300 (Data Access) in xmon, returning to main loop
xmon: WARNING: bad recursive fault on cpu 0x15

The root cause is that xmon is calling RTAS to turn off the surveillance
when entering xmon, and RTAS is requiring big endian parameters.

This patch is byte swapping the RTAS arguments when running in LE mode.

Cc: stable@vger.kernel.org
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-11-27 09:32:57 +11:00
Michael Ellerman
d8ee6f34fd powerpc/xmon: Fix build when 4xx=y and 44x=n
dump_tlb_44x() is only defined when 44x=y, but the ifdef in xmon.c
checks for 4xx, leading to a build failure:

  arch/powerpc/xmon/xmon.c:912:4: error: implicit declaration of function 'dump_tlb_44x'

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-11-12 16:54:54 +11:00
Alexander Graf
9178ba294b powerpc: Convert power off logic to pm_power_off
The generic Linux framework to power off the machine is a function pointer
called pm_power_off. The trick about this pointer is that device drivers can
potentially implement it rather than board files.

Today on powerpc we set pm_power_off to invoke our generic full machine power
off logic which then calls ppc_md.power_off to invoke machine specific power
off.

However, when we want to add a power off GPIO via the "gpio-poweroff" driver,
this card house falls apart. That driver only registers itself if pm_power_off
is NULL to ensure it doesn't override board specific logic. However, since we
always set pm_power_off to the generic power off logic (which will just not
power off the machine if no ppc_md.power_off call is implemented), we can't
implement power off via the generic GPIO power off driver.

To fix this up, let's get rid of the ppc_md.power_off logic and just always use
pm_power_off as was intended. Then individual drivers such as the GPIO power off
driver can implement power off logic via that function pointer.

With this patch set applied and a few patches on top of QEMU that implement a
power off GPIO on the virt e500 machine, I can successfully turn off my virtual
machine after halt.

Signed-off-by: Alexander Graf <agraf@suse.de>
[mpe: Squash into one patch and update changelog based on cover letter]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-11-03 12:12:51 +11:00
Anton Blanchard
a71d64b4dc powerpc: Hard disable interrupts in xmon
xmon only soft disables interrupts. This seems like a bad idea - we
certainly don't want decrementer and PMU exceptions going off when
we are debugging something inside xmon.

This issue was uncovered when the hard lockup detector went off
inside xmon. To ensure we wont get a spurious hard lockup warning,
I also call touch_nmi_watchdog() when exiting xmon.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-08-13 15:13:48 +10:00
Michael Ellerman
13b3d13b81 powerpc: Remove MMU_FTR_SLB
We now only support cpus that use an SLB, so we don't need an MMU
feature to indicate that.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-07-28 14:10:23 +10:00
Michael Ellerman
376af5947c powerpc: Remove STAB code
Old cpus didn't have a Segment Lookaside Buffer (SLB), instead they had
a Segment Table (STAB). Now that we've dropped support for those cpus,
we can remove the STAB support entirely.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-07-28 14:10:22 +10:00
Kees Cook
50b66dbf87 powerpc/xmon: avoid format string leaking to printk
This makes sure format strings cannot leak into printk (the string has
already been correctly processed for format arguments).

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-06-11 17:04:03 +10:00
Michael Ellerman
736256e4f1 powerpc/xmon: Fix up xmon format strings
There are a couple of places where xmon is using %x to print values that
are unsigned long.

I found this out the hard way recently:

 0:mon> p c000000000d0e7c8 c00000033dc90000 00000000a0000089 c000000000000000
 return value is 0x96300500

Which is calling find_linux_pte_or_hugepte(), the result should be a
kernel pointer. After decoding the page tables by hand I discovered the
correct value was c000000396300500.

So fix up that case and a few others.

We also use a mix of 0x%x, %x and %u to print cpu numbers. So
standardise on 0x%x.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-06-05 13:20:00 +10:00
Paul Gortmaker
21f585073d powerpc: Fix smp_processor_id() in preemptible splat in set_breakpoint
Currently, on 8641D, which doesn't set CONFIG_HAVE_HW_BREAKPOINT
we get the following splat:

BUG: using smp_processor_id() in preemptible [00000000] code: login/1382
caller is set_breakpoint+0x1c/0xa0
CPU: 0 PID: 1382 Comm: login Not tainted 3.15.0-rc3-00041-g2aafe1a4d451 #1
Call Trace:
[decd5d80] [c0008dc4] show_stack+0x50/0x158 (unreliable)
[decd5dc0] [c03c6fa0] dump_stack+0x7c/0xdc
[decd5de0] [c01f8818] check_preemption_disabled+0xf4/0x104
[decd5e00] [c00086b8] set_breakpoint+0x1c/0xa0
[decd5e10] [c00d4530] flush_old_exec+0x2bc/0x588
[decd5e40] [c011c468] load_elf_binary+0x2ac/0x1164
[decd5ec0] [c00d35f8] search_binary_handler+0xc4/0x1f8
[decd5ef0] [c00d4ee8] do_execve+0x3d8/0x4b8
[decd5f40] [c001185c] ret_from_syscall+0x0/0x38
 --- Exception: c01 at 0xfeee554
    LR = 0xfeee7d4

The call path in this case is:

	flush_thread
	   --> set_debug_reg_defaults
	     --> set_breakpoint
	       --> __get_cpu_var

Since preemption is enabled in the cleanup of flush thread, and
there is no need to disable it, introduce the distinction between
set_breakpoint and __set_breakpoint, leaving only the flush_thread
instance as the current user of set_breakpoint.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-05-20 10:54:06 +10:00
Philippe Bergheaud
72eceef67a powerpc: Fix xmon disassembler for little-endian
This patch fixes the disassembler of the powerpc kernel debugger xmon,
for little-endian.

Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-03-07 15:50:12 +11:00
Michael Ellerman
d2b496e5e1 powerpc/xmon: Don't signal we've entered until we're finished printing
Currently we set our cpu's bit in cpus_in_xmon, and then we take the
output lock and print the exception information.

This can race with the master cpu entering the command loop and printing
the backtrace. The result is that the backtrace gets garbled with
another cpu's exception print out.

Fix it by delaying the set of cpus_in_xmon until we are finished
printing.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-02-11 11:24:51 +11:00
Michael Ellerman
1507589787 powerpc/xmon: Fix timeout loop in get_output_lock()
As far as I can tell, our 70s era timeout loop in get_output_lock() is
generating no code.

This leads to the hostile takeover happening more or less simultaneously
on all cpus. The result is "interesting", some example output that is
more readable than most:

    cpu 0x1: Vector: 100 (Scypsut e0mx bR:e setV)e catto xc0p:u[ c 00
    c0:0  000t0o0V0erc0td:o5 rfc28050000]0c00 0 0  0 6t(pSrycsV1ppuot
    uxe 1m 2 0Rx21e3:0s0ce000c00000t00)00 60602oV2SerucSayt0y 0p 1sxs

Fix it by using udelay() in the timeout loop. The wait time and check
frequency are arbitrary, but seem to work OK. We already rely on
udelay() working so this is not a new dependency.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-02-11 11:24:51 +11:00
Michael Ellerman
730efb6193 powerpc/xmon: Don't loop forever in get_output_lock()
If we enter with xmon_speaker != 0 we skip the first cmpxchg(), we also
skip the while loop because xmon_speaker != last_speaker (0) - meaning we
skip the second cmpxchg() also.

Following that code path the compiler sees no memory barriers and so is
within its rights to never reload xmon_speaker. The end result is we loop
forever.

This manifests as all cpus being in xmon ('c' command), but they refuse
to take control when you switch to them ('c x' for cpu # x).

I have seen this deadlock in practice and also checked the generated code to
confirm this is what's happening.

The simplest fix is just to always try the cmpxchg().

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-02-11 11:24:50 +11:00
Mahesh Salgaonkar
729b0f7153 powerpc/book3s: Introduce exclusive emergency stack for machine check exception.
This patch introduces exclusive emergency stack for machine check exception.
We use emergency stack to handle machine check exception so that we can save
MCE information (srr1, srr0, dar and dsisr) before turning on ME bit and be
ready for re-entrancy. This helps us to prevent clobbering of MCE information
in case of nested machine checks.

The reason for using emergency stack over normal kernel stack is that the
machine check might occur in the middle of setting up a stack frame which may
result into improper use of kernel stack.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-05 16:02:05 +11:00
Paul Mackerras
fd3bb91287 powerpc/xmon: Fix printing of set of CPUs in xmon
Commit 24ec2125f3 ("powerpc/xmon: Use cpumask iterator to avoid warning")
replaced a loop from 0 to NR_CPUS-1 with a for_each_possible_cpu() loop,
which means that if the last possible cpu is in xmon, we print the
wrong value for the end of the range.  For example, if 4 cpus are
possible, NR_CPUS is 128, and all cpus are in xmon, we print "0-7f"
rather than "0-3".  The code also assumes that the set of possible
cpus is contiguous, which may not necessarily be true.

This fixes the code to check explicitly for contiguity, and to print
the ending value correctly.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-05 17:29:19 +10:00
Michael Ellerman
660e034ce1 powerpc: Add more trap names to xmon
We haven't updated these for a while it seems, it's nice to have in the
oops output.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-08-27 14:44:29 +10:00