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| author | David S. Miller <davem@davemloft.net> | 2010-04-11 02:44:30 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-04-11 02:44:30 -0700 |
| commit | 4a1032faac94ebbf647460ae3e06fc21146eb280 (patch) | |
| tree | 7f31b97beb0406faa1523e619289ad0ab07c9787 /arch/powerpc/kernel/misc.S | |
| parent | ae4e8d63b5619d4d95f1d2bfa2b836caa6e62d06 (diff) | |
| parent | 0eddb519b9127c73d53db4bf3ec1d45b13f844d1 (diff) | |
| download | linux-4a1032faac94ebbf647460ae3e06fc21146eb280.tar.gz linux-4a1032faac94ebbf647460ae3e06fc21146eb280.tar.bz2 linux-4a1032faac94ebbf647460ae3e06fc21146eb280.zip | |
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Diffstat (limited to 'arch/powerpc/kernel/misc.S')
| -rw-r--r-- | arch/powerpc/kernel/misc.S | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/misc.S b/arch/powerpc/kernel/misc.S index 2d29752cbe16..22e507c8a556 100644 --- a/arch/powerpc/kernel/misc.S +++ b/arch/powerpc/kernel/misc.S @@ -127,3 +127,29 @@ _GLOBAL(__setup_cpu_power7) _GLOBAL(__restore_cpu_power7) /* place holder */ blr + +/* + * Get a minimal set of registers for our caller's nth caller. + * r3 = regs pointer, r5 = n. + * + * We only get R1 (stack pointer), NIP (next instruction pointer) + * and LR (link register). These are all we can get in the + * general case without doing complicated stack unwinding, but + * fortunately they are enough to do a stack backtrace, which + * is all we need them for. + */ +_GLOBAL(perf_arch_fetch_caller_regs) + mr r6,r1 + cmpwi r5,0 + mflr r4 + ble 2f + mtctr r5 +1: PPC_LL r6,0(r6) + bdnz 1b + PPC_LL r4,PPC_LR_STKOFF(r6) +2: PPC_LL r7,0(r6) + PPC_LL r7,PPC_LR_STKOFF(r7) + PPC_STL r6,GPR1-STACK_FRAME_OVERHEAD(r3) + PPC_STL r4,_NIP-STACK_FRAME_OVERHEAD(r3) + PPC_STL r7,_LINK-STACK_FRAME_OVERHEAD(r3) + blr |