linux/arch
Robert Richter 16e5294e5f perf, x86: Force IBS LVT offset assignment for family 10h
On AMD family 10h we see firmware bug messages like the following:

 [Firmware Bug]: cpu 6, try to use APIC500 (LVT offset 0) for vector 0x10400, but the register is already in use for vector 0xf9 on another cpu
 [Firmware Bug]: cpu 6, IBS interrupt offset 0 not available (MSRC001103A=0x0000000000000100)
 [Firmware Bug]: using offset 1 for IBS interrupts
 [Firmware Bug]: workaround enabled for IBS LVT offset
 perf: AMD IBS detected (0x00000007)

We always see this, since the offsets are not assigned by the BIOS for
this family. Force LVT offset assignment in this case. If the OS
assignment fails, fallback to BIOS settings and try to setup this.

The fallback to BIOS settings weakens the family check since
force_ibs_eilvt_setup() may fail e.g. in case of virtual machines.
But setup may still succeed if BIOS offsets are correct.

Other families don't have a workaround implemented that assigns LVT
offsets. It's ok, to drop calling force_ibs_eilvt_setup() for that
families.

With the patch the [Firmware Bug] messages vanish. We see now:

 IBS: LVT offset 1 assigned
 perf: AMD IBS detected (0x00000007)

Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20111109162225.GO12451@erda.amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-05 09:32:59 +01:00
..
alpha
arm perf: Don't use -ENOSPC for out of PMU resources 2011-11-14 13:01:24 +01:00
avr32
blackfin
cris
frv
h8300
hexagon
ia64
m32r
m68k
microblaze
mips perf: Don't use -ENOSPC for out of PMU resources 2011-11-14 13:01:24 +01:00
mn10300
openrisc
parisc
powerpc
s390
score
sh
sparc
tile
um
unicore32
x86 perf, x86: Force IBS LVT offset assignment for family 10h 2011-12-05 09:32:59 +01:00
xtensa
.gitignore
Kconfig