diff options
| author | Anshuman Khandual <khandual@linux.vnet.ibm.com> | 2013-04-22 23:42:41 +0400 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2013-04-26 10:11:11 +0400 |
| commit | 73760931dcbcbe29eab72e06577a77c64f16fd02 (patch) | |
| tree | 37507048630e438266e49b9c3ef332911e21b847 /arch/powerpc/perf/bhrb.S | |
| parent | 95213959aefc94f1cfe6718449a8bcdc8df86060 (diff) | |
| download | linux-73760931dcbcbe29eab72e06577a77c64f16fd02.tar.xz | |
powerpc/perf: Add basic assembly code to read BHRB entries on POWER8
This patch adds the basic assembly code to read BHRB buffer. BHRB entries
are valid only after a PMU interrupt has happened (when MMCR0[PMAO]=1)
and BHRB has been freezed. BHRB read should not be attempted when it is
still enabled (MMCR0[PMAE]=1) and getting updated, as this can produce
non-deterministic results.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/perf/bhrb.S')
| -rw-r--r-- | arch/powerpc/perf/bhrb.S | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/powerpc/perf/bhrb.S b/arch/powerpc/perf/bhrb.S new file mode 100644 index 000000000000..d85f9a58ddbc --- /dev/null +++ b/arch/powerpc/perf/bhrb.S @@ -0,0 +1,44 @@ +/* + * Basic assembly code to read BHRB entries + * + * Copyright 2013 Anshuman Khandual, IBM Corporation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ +#include <asm/ppc_asm.h> +#include <asm/ppc-opcode.h> + + .text + +.balign 8 + +/* r3 = n (where n = [0-31]) + * The maximum number of BHRB entries supported with PPC_MFBHRBE instruction + * is 1024. We have limited number of table entries here as POWER8 implements + * 32 BHRB entries. + */ + +/* .global read_bhrb */ +_GLOBAL(read_bhrb) + cmpldi r3,31 + bgt 1f + ld r4,bhrb_table@got(r2) + sldi r3,r3,3 + add r3,r4,r3 + mtctr r3 + bctr +1: li r3,0 + blr + +#define MFBHRB_TABLE1(n) PPC_MFBHRBE(R3,n); blr +#define MFBHRB_TABLE2(n) MFBHRB_TABLE1(n); MFBHRB_TABLE1(n+1) +#define MFBHRB_TABLE4(n) MFBHRB_TABLE2(n); MFBHRB_TABLE2(n+2) +#define MFBHRB_TABLE8(n) MFBHRB_TABLE4(n); MFBHRB_TABLE4(n+4) +#define MFBHRB_TABLE16(n) MFBHRB_TABLE8(n); MFBHRB_TABLE8(n+8) +#define MFBHRB_TABLE32(n) MFBHRB_TABLE16(n); MFBHRB_TABLE16(n+16) + +bhrb_table: + MFBHRB_TABLE32(0) |