linux/arch/powerpc/include/asm/asm-compat.h
Paul Mackerras 9eff26ea48 powerpc/perf_events: Fix call-graph recording, add perf_arch_fetch_caller_regs
This implements a powerpc version of perf_arch_fetch_caller_regs
to get correct call-graphs.

It's implemented in assembly because that way we can be sure there isn't
a stack frame for perf_arch_fetch_caller_regs.  If it was in C, gcc might
or might not create a stack frame for it, which would affect the number
of levels we have to skip.

With this, we see results from perf record -e lock:lock_acquire like
this:

 # Samples: 24878
 #
 # Overhead         Command      Shared Object  Symbol
 # ........  ..............  .................  ......
 #
    14.99%            perf  [kernel.kallsyms]  [k] ._raw_spin_lock
                      |
                      --- ._raw_spin_lock
                         |
                         |--25.00%-- .alloc_fd
                         |          (nil)
                         |          |
                         |          |--50.00%-- .anon_inode_getfd
                         |          |          .sys_perf_event_open
                         |          |          syscall_exit
                         |          |          syscall
                         |          |          create_counter
                         |          |          __cmd_record
                         |          |          run_builtin
                         |          |          main
                         |          |          0xfd2e704
                         |          |          0xfd2e8c0
                         |          |          (nil)

... etc.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: anton@samba.org
Cc: linuxppc-dev@ozlabs.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100318050513.GA6575@drongo>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-18 06:48:29 +01:00

73 lines
2.0 KiB
C

#ifndef _ASM_POWERPC_ASM_COMPAT_H
#define _ASM_POWERPC_ASM_COMPAT_H
#include <asm/types.h>
#include <asm/ppc-opcode.h>
#ifdef __ASSEMBLY__
# define stringify_in_c(...) __VA_ARGS__
# define ASM_CONST(x) x
#else
/* This version of stringify will deal with commas... */
# define __stringify_in_c(...) #__VA_ARGS__
# define stringify_in_c(...) __stringify_in_c(__VA_ARGS__) " "
# define __ASM_CONST(x) x##UL
# define ASM_CONST(x) __ASM_CONST(x)
#endif
#ifdef __powerpc64__
/* operations for longs and pointers */
#define PPC_LL stringify_in_c(ld)
#define PPC_STL stringify_in_c(std)
#define PPC_LCMPI stringify_in_c(cmpdi)
#define PPC_LONG stringify_in_c(.llong)
#define PPC_LONG_ALIGN stringify_in_c(.balign 8)
#define PPC_TLNEI stringify_in_c(tdnei)
#define PPC_LLARX(t, a, b, eh) PPC_LDARX(t, a, b, eh)
#define PPC_STLCX stringify_in_c(stdcx.)
#define PPC_CNTLZL stringify_in_c(cntlzd)
#define PPC_LR_STKOFF 16
/* Move to CR, single-entry optimized version. Only available
* on POWER4 and later.
*/
#ifdef CONFIG_POWER4_ONLY
#define PPC_MTOCRF stringify_in_c(mtocrf)
#else
#define PPC_MTOCRF stringify_in_c(mtcrf)
#endif
#else /* 32-bit */
/* operations for longs and pointers */
#define PPC_LL stringify_in_c(lwz)
#define PPC_STL stringify_in_c(stw)
#define PPC_LCMPI stringify_in_c(cmpwi)
#define PPC_LONG stringify_in_c(.long)
#define PPC_LONG_ALIGN stringify_in_c(.balign 4)
#define PPC_TLNEI stringify_in_c(twnei)
#define PPC_LLARX(t, a, b, eh) PPC_LWARX(t, a, b, eh)
#define PPC_STLCX stringify_in_c(stwcx.)
#define PPC_CNTLZL stringify_in_c(cntlzw)
#define PPC_MTOCRF stringify_in_c(mtcrf)
#define PPC_LR_STKOFF 4
#endif
#ifdef __KERNEL__
#ifdef CONFIG_IBM405_ERR77
/* Erratum #77 on the 405 means we need a sync or dcbt before every
* stwcx. The old ATOMIC_SYNC_FIX covered some but not all of this.
*/
#define PPC405_ERR77(ra,rb) stringify_in_c(dcbt ra, rb;)
#define PPC405_ERR77_SYNC stringify_in_c(sync;)
#else
#define PPC405_ERR77(ra,rb)
#define PPC405_ERR77_SYNC
#endif
#endif
#endif /* _ASM_POWERPC_ASM_COMPAT_H */