diff options
| -rw-r--r-- | arch/sparc/kernel/helpers.S | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/arch/sparc/kernel/helpers.S b/arch/sparc/kernel/helpers.S index 314dd0c9fc5b..92090cc9e829 100644 --- a/arch/sparc/kernel/helpers.S +++ b/arch/sparc/kernel/helpers.S @@ -46,6 +46,81 @@ stack_trace_flush: nop .size stack_trace_flush,.-stack_trace_flush +#ifdef CONFIG_PERF_EVENTS + .globl perf_arch_fetch_caller_regs + .type perf_arch_fetch_caller_regs,#function +perf_arch_fetch_caller_regs: + /* We always read the %pstate into %o5 since we will use + * that to construct a fake %tstate to store into the regs. + */ + rdpr %pstate, %o5 + brz,pn %o2, 50f + mov %o2, %g7 + + /* Turn off interrupts while we walk around the register + * window by hand. + */ + wrpr %o5, PSTATE_IE, %pstate + + /* The %canrestore tells us how many register windows are + * still live in the chip above us, past that we have to + * walk the frame as saved on the stack. We stash away + * the %cwp in %g1 so we can return back to the original + * register window. + */ + rdpr %cwp, %g1 + rdpr %canrestore, %g2 + sub %g1, 1, %g3 + + /* We have the skip count in %g7, if it hits zero then + * %fp/%i7 are the registers we need. Otherwise if our + * %canrestore count maintained in %g2 hits zero we have + * to start traversing the stack. + */ +10: brz,pn %g2, 4f + sub %g2, 1, %g2 + wrpr %g3, %cwp + subcc %g7, 1, %g7 + bne,pt %xcc, 10b + sub %g3, 1, %g3 + + /* We found the values we need in the cpu's register + * windows. + */ + mov %fp, %g3 + ba,pt %xcc, 3f + mov %i7, %g2 + +50: mov %fp, %g3 + ba,pt %xcc, 2f + mov %i7, %g2 + + /* We hit the end of the valid register windows in the + * cpu, start traversing the stack frame. + */ +4: mov %fp, %g3 + +20: ldx [%g3 + STACK_BIAS + RW_V9_I7], %g2 + subcc %g7, 1, %g7 + bne,pn %xcc, 20b + ldx [%g3 + STACK_BIAS + RW_V9_I6], %g3 + + /* Restore the current register window position and + * re-enable interrupts. + */ +3: wrpr %g1, %cwp + wrpr %o5, %pstate + +2: stx %g3, [%o0 + PT_V9_FP] + sllx %o5, 8, %o5 + stx %o5, [%o0 + PT_V9_TSTATE] + stx %g2, [%o0 + PT_V9_TPC] + add %g2, 4, %g2 + retl + stx %g2, [%o0 + PT_V9_TNPC] + .size perf_arch_fetch_caller_regs,.-perf_arch_fetch_caller_regs +#endif /* CONFIG_PERF_EVENTS */ + #ifdef CONFIG_SMP .globl hard_smp_processor_id .type hard_smp_processor_id,#function |