On power8 we have a new SIER (Sampled Instruction Event Register), which
captures information about instructions when we have random sampling
enabled.
Add support for loading the SIER into pt_regs, overloading regs->dar.
Also set the new NO_SIPR flag in regs->result if we don't have SIPR.
Update regs_sihv/sipr() to look for SIPR/SIHV in SIER.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In perf_ip_adjust() we potentially use the MMCRA[SLOT] field to adjust
the reported IP of a sampled instruction.
Currently the logic is written so that if the backend does NOT have
the PPMU_ALT_SIPR flag set then we assume MMCRA[SLOT] exists.
However on power8 we do not want to set ALT_SIPR (it's in a third
location), and we also do not have MMCRA[SLOT].
So add a new flag which only indicates whether MMCRA[SLOT] exists.
Naively we'd set it on everything except power6/7, because they set
ALT_SIPR, and we've reversed the polarity of the flag. But it's more
complicated than that.
mpc7450 is 32-bit, and uses its own version of perf_ip_adjust()
which doesn't use MMCRA[SLOT], so it doesn't need the new flag set and
the behaviour is unchanged.
PPC970 (and I assume power4) don't have MMCRA[SLOT], so shouldn't have
the new flag set. This is a behaviour change on those cpus, though we
were probably getting lucky and the bits in question were 0.
power5 and power5+ set the new flag, behaviour unchanged.
power6 & power7 do not set the new flag, behaviour unchanged.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Pull powerpc updates from Benjamin Herrenschmidt:
"So from the depth of frozen Minnesota, here's the powerpc pull request
for 3.9. It has a few interesting highlights, in addition to the
usual bunch of bug fixes, minor updates, embedded device tree updates
and new boards:
- Hand tuned asm implementation of SHA1 (by Paulus & Michael
Ellerman)
- Support for Doorbell interrupts on Power8 (kind of fast
thread-thread IPIs) by Ian Munsie
- Long overdue cleanup of the way we handle relocation of our open
firmware trampoline (prom_init.c) on 64-bit by Anton Blanchard
- Support for saving/restoring & context switching the PPR (Processor
Priority Register) on server processors that support it. This
allows the kernel to preserve thread priorities established by
userspace. By Haren Myneni.
- DAWR (new watchpoint facility) support on Power8 by Michael Neuling
- Ability to change the DSCR (Data Stream Control Register) which
controls cache prefetching on a running process via ptrace by
Alexey Kardashevskiy
- Support for context switching the TAR register on Power8 (new
branch target register meant to be used by some new specific
userspace perf event interrupt facility which is yet to be enabled)
by Ian Munsie.
- Improve preservation of the CFAR register (which captures the
origin of a branch) on various exception conditions by Paulus.
- Move the Bestcomm DMA driver from arch powerpc to drivers/dma where
it belongs by Philippe De Muyter
- Support for Transactional Memory on Power8 by Michael Neuling
(based on original work by Matt Evans). For those curious about
the feature, the patch contains a pretty good description."
(See commit db8ff907027b: "powerpc: Documentation for transactional
memory on powerpc" for the mentioned description added to the file
Documentation/powerpc/transactional_memory.txt)
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (140 commits)
powerpc/kexec: Disable hard IRQ before kexec
powerpc/85xx: l2sram - Add compatible string for BSC9131 platform
powerpc/85xx: bsc9131 - Correct typo in SDHC device node
powerpc/e500/qemu-e500: enable coreint
powerpc/mpic: allow coreint to be determined by MPIC version
powerpc/fsl_pci: Store the pci ctlr device ptr in the pci ctlr struct
powerpc/85xx: Board support for ppa8548
powerpc/fsl: remove extraneous DIU platform functions
arch/powerpc/platforms/85xx/p1022_ds.c: adjust duplicate test
powerpc: Documentation for transactional memory on powerpc
powerpc: Add transactional memory to pseries and ppc64 defconfigs
powerpc: Add config option for transactional memory
powerpc: Add transactional memory to POWER8 cpu features
powerpc: Add new transactional memory state to the signal context
powerpc: Hook in new transactional memory code
powerpc: Routines for FP/VSX/VMX unavailable during a transaction
powerpc: Add transactional memory unavaliable execption handler
powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes
powerpc: Add FP/VSX and VMX register load functions for transactional memory
powerpc: Add helper functions for transactional memory context switching
...
Make some POWER7-specific perf events available in sysfs.
$ /bin/ls -1 /sys/bus/event_source/devices/cpu/events/
branch-instructions
branch-misses
cache-misses
cache-references
cpu-cycles
instructions
PM_BRU_FIN
PM_BRU_MPRED
PM_CMPLU_STALL
PM_CYC
PM_GCT_NOSLOT_CYC
PM_INST_CMPL
PM_LD_MISS_L1
PM_LD_REF_L1
stalled-cycles-backend
stalled-cycles-frontend
where the 'PM_*' events are POWER specific and the others are the
generic events.
This will enable users to specify these events with their symbolic
names rather than with their raw code.
perf stat -e 'cpu/PM_CYC' ...
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anton Blanchard <anton@au1.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: linuxppc-dev@ozlabs.org
Link: http://lkml.kernel.org/r/20130123062528.GE13720@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Make the generic perf events in POWER7 available via sysfs.
$ ls /sys/bus/event_source/devices/cpu/events
branch-instructions
branch-misses
cache-misses
cache-references
cpu-cycles
instructions
stalled-cycles-backend
stalled-cycles-frontend
$ cat /sys/bus/event_source/devices/cpu/events/cache-misses
event=0x400f0
This patch is based on commits that implement this functionality on x86.
Eg:
commit a47473939d
Author: Jiri Olsa <jolsa@redhat.com>
Date: Wed Oct 10 14:53:11 2012 +0200
perf/x86: Make hardware event translations available in sysfs
Changelog:[v2]
[Jiri Osla] Drop EVENT_ID() macro since it is only used once.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anton Blanchard <anton@au1.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: linuxppc-dev@ozlabs.org
Link: http://lkml.kernel.org/r/20130123062454.GD13720@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Change the representation of the PMU flags from decimal to hex since they
are bitfields which are easier to read in hex.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
powerpc/perf: Sample only if SIAR-Valid bit is set in P7+
On POWER7+ two new bits (mmcra[35] and mmcra[36]) indicate whether the
contents of SIAR and SDAR are valid.
For marked instructions on P7+, we must save the contents of SIAR and
SDAR registers only if these new bits are set.
This code/check for the SIAR-Valid bit is specific to P7+, so rather than
waste a CPU-feature bit use the PVR flag.
Note that Carl Love proposed a similar change for oprofile:
https://lkml.org/lkml/2012/6/22/309
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
970 and Power4 don't support "continuous sampling" which means that
when we aren't in marked instruction sampling mode (marked events),
SIAR isn't updated with the last instruction sampled before the
perf interrupt. On those processors, we must thus use the exception
SRR0 value as the sampled instruction pointer.
Those processors also don't support the SIPR and SIHV bits in MMCRA
which means we need some kind of heuristic to decide if SIAR values
represent kernel or user addresses.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Put the logic to compute the event index into a per pmu method. This
is required because the x86 rules are weird and wonderful and don't
match the capabilities of the current scheme.
AFAIK only powerpc actually has a usable userspace read of the PMCs
but I'm not at all sure anybody actually used that.
ARM is restored to the default since it currently does not support
userspace access at all. And all software events are provided with a
method that reports their index as 0 (disabled).
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Arun Sharma <asharma@fb.com>
Link: http://lkml.kernel.org/n/tip-dfydxodki16lylkt3gl2j7cw@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This implements perf_event support for the Freescale embedded performance
monitor, based on the existing perf_event.c that supports server/classic
chips.
Some limitations:
- Performance monitor interrupts are regular EE interrupts, and thus you
can't profile places with interrupts disabled. We may want to implement
soft IRQ-disabling, with perfmon interrupts exempted and treated as NMIs.
- When trying to schedule multiple event groups at once, and using
restricted events, situations could arise where scheduling fails even
though it would be possible. Consider three groups, each with two events.
One group has restricted events, the others don't. The two non-restricted
groups are scheduled, then one is removed, which happens to occupy the two
counters that can't do restricted events. The remaining non-restricted
group will not be moved to the non-restricted-capable counters to make
room if the restricted group tries to be scheduled.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Michael Ellerman