powerpc/perf: Add basic assembly code to read BHRB entries on POWER8
authorAnshuman Khandual <khandual@linux.vnet.ibm.com>
Mon, 22 Apr 2013 19:42:41 +0000 (19:42 +0000)
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>
Fri, 26 Apr 2013 06:11:11 +0000 (16:11 +1000)
commit73760931dcbcbe29eab72e06577a77c64f16fd02
tree37507048630e438266e49b9c3ef332911e21b847
parent95213959aefc94f1cfe6718449a8bcdc8df86060
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>
arch/powerpc/perf/Makefile
arch/powerpc/perf/bhrb.S [new file with mode: 0644]