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2013-09-06Merge branch 'next' of ↵Linus Torvalds4-2/+153
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc Pull powerpc updates from Ben Herrenschmidt: "Here's the powerpc batch for this merge window. Some of the highlights are: - A bunch of endian fixes ! We don't have full LE support yet in that release but this contains a lot of fixes all over arch/powerpc to use the proper accessors, call the firmware with the right endian mode, etc... - A few updates to our "powernv" platform (non-virtualized, the one to run KVM on), among other, support for bridging the P8 LPC bus for UARTs, support and some EEH fixes. - Some mpc51xx clock API cleanups in preparation for a clock API overhaul - A pile of cleanups of our old math emulation code, including better support for using it to emulate optional FP instructions on embedded chips that otherwise have a HW FPU. - Some infrastructure in selftest, for powerpc now, but could be generalized, initially used by some tests for our perf instruction counting code. - A pile of fixes for hotplug on pseries (that was seriously bitrotting) - The usual slew of freescale embedded updates, new boards, 64-bit hiberation support, e6500 core PMU support, etc..." * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (146 commits) powerpc: Correct FSCR bit definitions powerpc/xmon: Fix printing of set of CPUs in xmon powerpc/pseries: Move lparcfg.c to platforms/pseries powerpc/powernv: Return secondary CPUs to firmware on kexec powerpc/btext: Fix CONFIG_PPC_EARLY_DEBUG_BOOTX on ppc32 powerpc: Cleanup handling of the DSCR bit in the FSCR register powerpc/pseries: Child nodes are not detached by dlpar_detach_node powerpc/pseries: Add mising of_node_put in delete_dt_node powerpc/pseries: Make dlpar_configure_connector parent node aware powerpc/pseries: Do all node initialization in dlpar_parse_cc_node powerpc/pseries: Fix parsing of initial node path in update_dt_node powerpc/pseries: Pack update_props_workarea to map correctly to rtas buffer header powerpc/pseries: Fix over writing of rtas return code in update_dt_node powerpc/pseries: Fix creation of loop in device node property list powerpc: Skip emulating & leave interrupts off for kernel program checks powerpc: Add more exception trampolines for hypervisor exceptions powerpc: Fix location and rename exception trampolines powerpc: Add more trap names to xmon powerpc/pseries: Add a warning in the case of cross-cpu VPA registration powerpc: Update the 00-Index in Documentation/powerpc ...
2013-08-15Merge tag 'v3.11-rc5' into perf/coreIngo Molnar2-15/+22
Merge Linux 3.11-rc5, to sync up with the latest upstream fixes since -rc1. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-08-14powerpc: Fix a number of sparse warningsAnton Blanchard1-1/+1
Address some of the trivial sparse warnings in arch/powerpc. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-08-09Merge remote-tracking branch 'scott/next' into nextBenjamin Herrenschmidt3-1/+152
Merge some Freescale updates from Scott Wood
2013-08-08powerpc/perf: Add e6500 PMU driverPriyanka Jain2-1/+122
e6500 core performance monitors has the following features: - 6 performance monitor counters - 512 events supported - no threshold events e6500 PMU has more specific events (Data L1 cache misses, Instruction L1 cache misses, etc ) than e500 PMU (which only had Data L1 cache reloads, etc). Where available, the more specific events have been used which will produce slightly different results than e500 PMU equivalents. Signed-off-by: Priyanka Jain <Priyanka.Jain@freescale.com> Signed-off-by: Lijun Pan <Lijun.Pan@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-08-08powerpc/perf: add 2 additional performance monitor counters for e6500 coreLijun Pan1-0/+24
There are 6 counters in e6500 core instead of 4 in e500 core. Signed-off-by: Lijun Pan <Lijun.Pan@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-08-08powerpc/perf: increase the perf HW events to 6Catalin Udma1-0/+6
This change is required after the e6500 perf support has been added. There are 6 counters in e6500 core instead of 4 in e500 core and the MAX_HWEVENTS counter should be changed accordingly from 4 to 6. Added also runtime check for counters overflow. Signed-off-by: Catalin Udma <catalin.udma@freescale.com> Signed-off-by: Lijun Pan <Lijun.Pan@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-08-01powerpc/perf: Export PERF_EVENT_CONFIG_EBB_SHIFT to userspaceMichael Ellerman2-4/+4
We use bit 63 of the event code for userspace to request that the event be counted using EBB (Event Based Branches). Export this value, making it part of the API - though only on processors that support EBB. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-24powerpc/perf: BHRB filter configuration should follow the taskAnshuman Khandual1-1/+4
When the task moves around the system, the corresponding cpuhw per cpu strcuture should be popullated with the BHRB filter request value so that PMU could be configured appropriately with that during the next call into power_pmu_enable(). Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-24powerpc/perf: Ignore separate BHRB privilege state filter requestAnshuman Khandual1-9/+4
Completely ignore BHRB privilege state filter request as we are already configuring that with privilege state filtering attribute for the accompanying PMU event. This would help achieve cleaner user space interaction for BHRB. This patch fixes a situation like this Before patch:- ------------ ./perf record -j any -e branch-misses:k ls Error: The sys_perf_event_open() syscall returned with 95 (Operation not supported) for event (branch-misses:k). /bin/dmesg may provide additional information. No CONFIG_PERF_EVENTS=y kernel support configured? Here 'perf record' actually copies over ':k' filter request into BHRB privilege state filter config and our previous check in kernel would fail that. After patch:- ------------- ./perf record -j any -e branch-misses:k ls perf perf.data perf.data.old test-mmap-ring [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.002 MB perf.data (~102 samples)] Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-24powerpc/perf: Set PPC_FEATURE2_EBB when we register the power8 PMUMichael Ellerman1-1/+10
The presence or absence of EBB is advertised to userspace via the presence or absence of PPC_FEATURE2_EBB in cpu_user_features2. Because the kernel can be built without PMU support, we should only add PPC_FEATURE2_EBB to cpu_user_features2 when we successfully register the power8 PMU support. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-19Merge tag 'perf-core-for-mingo' of ↵Ingo Molnar2-116/+580
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo: * Add missing 'finished_round' event forwarding in 'perf inject', from Adrian Hunter. * Assorted tidy ups, from Adrian Hunter. * Fall back to sysfs event names when parsing fails, from Andi Kleen. * List pmu events in perf list, from Andi Kleen. * Cleanup some memory allocation/freeing uses, from David Ahern. * Add option to collapse undesired parts of call graph, from Greg Price. * Prep work for multi perf data file storage, from Jiri Olsa. * Add support for more than two files comparision in 'perf diff', from Jiri Olsa * A few more 'perf test' improvements, from Jiri Olsa * libtraceevent cleanups, from Namhyung Kim. * Remove odd build stall in 'perf sched' by moving a large struct initialization from a local variable to a global one, from Namhyung Kim. * Add support for callchains in the gtk UI, from Namhyung Kim. * Do not apply symfs for an absolute vmlinux path, fix from Namhyung Kim. * Use default include path notation for libtraceevent, from Robert Richter. * Fix 'make tools/perf', from Robert Richter. * Make Power7 events available, from Runzhen Wang. * Add --objdump option to 'perf top', from Sukadev Bhattiprolu. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-14Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-6/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: - fix for do_div() abuse on x86 - locking fix in perf core - a pile of (build) fixes and cleanups in perf tools * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits) perf/x86: Fix incorrect use of do_div() in NMI warning perf: Fix perf_lock_task_context() vs RCU perf: Remove WARN_ON_ONCE() check in __perf_event_enable() for valid scenario perf: Clone child context from parent context pmu perf script: Fix broken include in Context.xs perf tools: Fix -ldw/-lelf link test when static linking perf tools: Revert regression in configuration of Python support perf tools: Fix perf version generation perf stat: Fix per-socket output bug for uncore events perf symbols: Fix vdso list searching perf evsel: Fix missing increment in sample parsing perf tools: Update symbol_conf.nr_events when processing attribute events perf tools: Fix new_term() missing free on error path perf tools: Fix parse_events_terms() segfault on error path perf evsel: Fix count parameter to read call in event_format__new perf tools: fix a typo of a Power7 event name perf tools: Fix -x/--exclude-other option for report command perf evlist: Enhance perf_evlist__start_workload() perf record: Remove -f/--force option perf record: Remove -A/--append option ...
2013-07-12perf tools: Make Power7 events available for perfRunzhen Wang2-116/+580
Power7 supports over 530 different perf events but only a small subset of these can be specified by name, for the remaining events, we must specify them by their raw code: perf stat -e r2003c <application> This patch makes all the POWER7 events available in sysfs. So we can instead specify these as: perf stat -e 'cpu/PM_CMPLU_STALL_DFU/' <application> where PM_CMPLU_STALL_DFU is the r2003c in previous example. Before this patch is applied, the size of power7-pmu.o is: $ size arch/powerpc/perf/power7-pmu.o text data bss dec hex filename 3073 2720 0 5793 16a1 arch/powerpc/perf/power7-pmu.o and after the patch is applied, it is: $ size arch/powerpc/perf/power7-pmu.o text data bss dec hex filename 15950 31112 0 47062 b7d6 arch/powerpc/perf/power7-pmu.o For the run time overhead, I use two scripts, one is "event_name.sh", which contains 50 event names, it looks like: # ./perf record -e 'cpu/PM_CMPLU_STALL_DFU/' -e ..... /bin/sleep 1 the other one is named "event_code.sh" which use corresponding events raw code instead of events names, it looks like: # ./perf record -e r2003c -e ...... /bin/sleep 1 below is the result. Using events name: [root@localhost perf]# time ./event_name.sh [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.002 MB perf.data (~102 samples) ] real 0m1.192s user 0m0.028s sys 0m0.106s Using events raw code: [root@localhost perf]# time ./event_code.sh [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.003 MB perf.data (~112 samples) ] real 0m1.198s user 0m0.028s sys 0m0.105s Signed-off-by: Runzhen Wang <runzhen@linux.vnet.ibm.com> Acked-by: Michael Ellerman <michael@ellerman.id.au> Cc: icycoder@gmail.com Cc: linuxppc-dev@lists.ozlabs.org Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Runzhen Wang <runzhew@clemson.edu> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1372407297-6996-3-git-send-email-runzhen@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-07-09perf tools: fix a typo of a Power7 event nameRunzhen Wang1-6/+6
In the Power7 PMU guide: https://www.power.org/documentation/commonly-used-metrics-for-performance-analysis/ PM_BRU_MPRED is referred to as PM_BR_MPRED. It fixed the typo by changing the name of the event in kernel and documentation accordingly. This patch changes the ABI, there are some reasons I think it's ok: - It is relatively new interface, specific to the Power7 platform. - No tools that we know of actually use this interface at this point (none are listed near the interface). - Users of this interface (eg oprofile users migrating to perf) would be more used to the "PM_BR_MPRED" rather than "PM_BRU_MPRED". - These are in the ABI/testing at this point rather than ABI/stable, so hoping we have some wiggle room. Signed-off-by: Runzhen Wang <runzhen@linux.vnet.ibm.com> Acked-by: Michael Ellerman <michael@ellerman.id.au> Cc: icycoder@gmail.com Cc: linuxppc-dev@lists.ozlabs.org Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Runzhen Wang <runzhew@clemson.edu> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1372407297-6996-2-git-send-email-runzhen@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-07-04Merge branch 'next' of ↵Linus Torvalds2-39/+224
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc Pull powerpc updates from Ben Herrenschmidt: "This is the powerpc changes for the 3.11 merge window. In addition to the usual bug fixes and small updates, the main highlights are: - Support for transparent huge pages by Aneesh Kumar for 64-bit server processors. This allows the use of 16M pages as transparent huge pages on kernels compiled with a 64K base page size. - Base VFIO support for KVM on power by Alexey Kardashevskiy - Wiring up of our nvram to the pstore infrastructure, including putting compressed oopses in there by Aruna Balakrishnaiah - Move, rework and improve our "EEH" (basically PCI error handling and recovery) infrastructure. It is no longer specific to pseries but is now usable by the new "powernv" platform as well (no hypervisor) by Gavin Shan. - I fixed some bugs in our math-emu instruction decoding and made it usable to emulate some optional FP instructions on processors with hard FP that lack them (such as fsqrt on Freescale embedded processors). - Support for Power8 "Event Based Branch" facility by Michael Ellerman. This facility allows what is basically "userspace interrupts" for performance monitor events. - A bunch of Transactional Memory vs. Signals bug fixes and HW breakpoint/watchpoint fixes by Michael Neuling. And more ... I appologize in advance if I've failed to highlight something that somebody deemed worth it." * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (156 commits) pstore: Add hsize argument in write_buf call of pstore_ftrace_call powerpc/fsl: add MPIC timer wakeup support powerpc/mpic: create mpic subsystem object powerpc/mpic: add global timer support powerpc/mpic: add irq_set_wake support powerpc/85xx: enable coreint for all the 64bit boards powerpc/8xx: Erroneous double irq_eoi() on CPM IRQ in MPC8xx powerpc/fsl: Enable CONFIG_E1000E in mpc85xx_smp_defconfig powerpc/mpic: Add get_version API both for internal and external use powerpc: Handle both new style and old style reserve maps powerpc/hw_brk: Fix off by one error when validating DAWR region end powerpc/pseries: Support compression of oops text via pstore powerpc/pseries: Re-organise the oops compression code pstore: Pass header size in the pstore write callback powerpc/powernv: Fix iommu initialization again powerpc/pseries: Inform the hypervisor we are using EBB regs powerpc/perf: Add power8 EBB support powerpc/perf: Core EBB support for 64-bit book3s powerpc/perf: Drop MMCRA from thread_struct powerpc/perf: Don't enable if we have zero events ...
2013-07-03Merge branch 'perf-core-for-linus' of ↵Linus Torvalds1-0/+73
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "Kernel improvements: - watchdog driver improvements by Li Zefan - Power7 CPI stack events related improvements by Sukadev Bhattiprolu - event multiplexing via hrtimers and other improvements by Stephane Eranian - kernel stack use optimization by Andrew Hunter - AMD IOMMU uncore PMU support by Suravee Suthikulpanit - NMI handling rate-limits by Dave Hansen - various hw_breakpoint fixes by Oleg Nesterov - hw_breakpoint overflow period sampling and related signal handling fixes by Jiri Olsa - Intel Haswell PMU support by Andi Kleen Tooling improvements: - Reset SIGTERM handler in workload child process, fix from David Ahern. - Makefile reorganization, prep work for Kconfig patches, from Jiri Olsa. - Add automated make test suite, from Jiri Olsa. - Add --percent-limit option to 'top' and 'report', from Namhyung Kim. - Sorting improvements, from Namhyung Kim. - Expand definition of sysfs format attribute, from Michael Ellerman. Tooling fixes: - 'perf tests' fixes from Jiri Olsa. - Make Power7 CPI stack events available in sysfs, from Sukadev Bhattiprolu. - Handle death by SIGTERM in 'perf record', fix from David Ahern. - Fix printing of perf_event_paranoid message, from David Ahern. - Handle realloc failures in 'perf kvm', from David Ahern. - Fix divide by 0 in variance, from David Ahern. - Save parent pid in thread struct, from David Ahern. - Handle JITed code in shared memory, from Andi Kleen. - Fixes for 'perf diff', from Jiri Olsa. - Remove some unused struct members, from Jiri Olsa. - Add missing liblk.a dependency for python/perf.so, fix from Jiri Olsa. - Respect CROSS_COMPILE in liblk.a, from Rabin Vincent. - No need to do locking when adding hists in perf report, only 'top' needs that, from Namhyung Kim. - Fix alignment of symbol column in in the hists browser (top, report) when -v is given, from NAmhyung Kim. - Fix 'perf top' -E option behavior, from Namhyung Kim. - Fix bug in isupper() and islower(), from Sukadev Bhattiprolu. - Fix compile errors in bp_signal 'perf test', from Sukadev Bhattiprolu. ... and more things" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (102 commits) perf/x86: Disable PEBS-LL in intel_pmu_pebs_disable() perf/x86: Fix shared register mutual exclusion enforcement perf/x86/intel: Support full width counting x86: Add NMI duration tracepoints perf: Drop sample rate when sampling is too slow x86: Warn when NMI handlers take large amounts of time hw_breakpoint: Introduce "struct bp_cpuinfo" hw_breakpoint: Simplify *register_wide_hw_breakpoint() hw_breakpoint: Introduce cpumask_of_bp() hw_breakpoint: Simplify the "weight" usage in toggle_bp_slot() paths hw_breakpoint: Simplify list/idx mess in toggle_bp_slot() paths perf/x86/intel: Add mem-loads/stores support for Haswell perf/x86/intel: Support Haswell/v4 LBR format perf/x86/intel: Move NMI clearing to end of PMI handler perf/x86/intel: Add Haswell PEBS support perf/x86/intel: Add simple Haswell PMU support perf/x86/intel: Add Haswell PEBS record support perf/x86/intel: Fix sparse warning perf/x86/amd: AMD IOMMU Performance Counter PERF uncore PMU implementation perf/x86/amd: Add IOMMU Performance Counter resource management ...
2013-07-01powerpc/perf: Add power8 EBB supportMichael Ellerman1-12/+33
Add logic to the power8 PMU code to support EBB. Future processors would also be expected to implement similar constraints. At that time we could possibly factor these out into common code. Finally mark the power8 PMU as supporting EBB, which is the actual enable switch which allows EBBs to be configured. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01powerpc/perf: Core EBB support for 64-bit book3sMichael Ellerman1-13/+148
Add support for EBB (Event Based Branches) on 64-bit book3s. See the included documentation for more details. EBBs are a feature which allows the hardware to branch directly to a specified user space address when a PMU event overflows. This can be used by programs for self-monitoring with no kernel involvement in the inner loop. Most of the logic is in the generic book3s code, primarily to avoid a proliferation of PMU callbacks. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01powerpc/perf: Don't enable if we have zero eventsMichael Ellerman1-2/+5
In power_pmu_enable() we still enable the PMU even if we have zero events. This should have no effect but doesn't make much sense. Instead just return after telling the hypervisor that we are not using the PMCs. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> CC: <stable@vger.kernel.org> [v3.10] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01powerpc/perf: Use existing out label in power_pmu_enable()Michael Ellerman1-4/+5
In power_pmu_enable() we can use the existing out label to reduce the number of return paths. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> CC: <stable@vger.kernel.org> [v3.10] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01powerpc/perf: Freeze PMC5/6 if we're not using themMichael Ellerman2-2/+7
On Power8 we can freeze PMC5 and 6 if we're not using them. Normally they run all the time. As noticed by Anshuman, we should unfreeze them when we disable the PMU as there are legacy tools which expect them to run all the time. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> CC: <stable@vger.kernel.org> [v3.10] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01powerpc/perf: Rework disable logic in pmu_disable()Michael Ellerman1-12/+19
In pmu_disable() we disable the PMU by setting the FC (Freeze Counters) bit in MMCR0. In order to do this we have to read/modify/write MMCR0. It's possible that we read a value from MMCR0 which has PMAO (PMU Alert Occurred) set. When we write that value back it will cause an interrupt to occur. We will then end up in the PMU interrupt handler even though we are supposed to have just disabled the PMU. We can avoid this by making sure we never write PMAO back. We should not lose interrupts because when the PMU is re-enabled the overflowed values will cause another interrupt. We also reorder the clearing of SAMPLE_ENABLE so that is done after the PMU is frozen. Otherwise there is a small window between the clearing of SAMPLE_ENABLE and the setting of FC where we could take an interrupt and incorrectly see SAMPLE_ENABLE not set. This would for example change the logic in perf_read_regs(). Signed-off-by: Michael Ellerman <michael@ellerman.id.au> CC: <stable@vger.kernel.org> [v3.10] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01powerpc/perf: Check that events only include valid bits on Power8Michael Ellerman1-0/+13
A mistake we have made in the past is that we pull out the fields we need from the event code, but don't check that there are no unknown bits set. This means that we can't ever assign meaning to those unknown bits in future. Although we have once again failed to do this at release, it is still early days for Power8 so I think we can still slip this in and get away with it. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> CC: <stable@vger.kernel.org> [v3.10] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01powerpc: Delete __cpuinit usage from all usersPaul Gortmaker1-2/+2
The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. This removes all the powerpc uses of the __cpuinit macros. There are no __CPUINIT users in assembly files in powerpc. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Josh Boyer <jwboyer@gmail.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-10powerpc/perf: Fix deadlock caused by calling printk() in PMU exceptionMichael Ellerman1-1/+1
In commit bc09c21 "Fix finding overflowed PMC in interrupt" we added a printk() to the PMU exception handler. Unfortunately that is not safe. The problem is that the PMU exception may run even when interrupts are soft disabled, aka NMI context. We do this so that we can profile parts of the kernel that have interrupts soft-disabled. But by calling printk() from the exception handler, we can potentially deadlock in the printk code on logbuf_lock, eg: [c00000038ba575c0] c000000000081928 .vprintk_emit+0xa8/0x540 [c00000038ba576a0] c0000000007bcde8 .printk+0x48/0x58 [c00000038ba57710] c000000000076504 .perf_event_interrupt+0x2d4/0x490 [c00000038ba57810] c00000000001f6f8 .performance_monitor_exception+0x48/0x60 [c00000038ba57880] c0000000000032cc performance_monitor_common+0x14c/0x180 --- Exception: f01 (Performance Monitor) at c0000000007b25d4 ._raw_spin_lock_irq +0x64/0xc0 [c00000038ba57bf0] c00000000007ed90 .devkmsg_read+0xd0/0x5a0 [c00000038ba57d00] c0000000001c2934 .vfs_read+0xc4/0x1e0 [c00000038ba57d90] c0000000001c2cd8 .SyS_read+0x58/0xd0 [c00000038ba57e30] c000000000009d54 syscall_exit+0x0/0x98 --- Exception: c01 (System Call) at 00001fffffbf6f7c SP (3ffff6d4de10) is in userspace Fix it by making sure we only call printk() when we are not in NMI context. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Cc: <stable@vger.kernel.org> # 3.9 Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-01powerpc/perf: Add missing SIER supportMichael Ellerman1-12/+25
Commit 8f61aa3 "Add support for SIER" missed updates to siar_valid() and perf_get_data_addr(). In both cases we need to check the SIER instead of mmcra. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-01powerpc/perf: Revert to original NO_SIPR logicMichael Ellerman1-24/+6
This is a revert and then some of commit 860aad7 "Add regs_no_sipr()". This workaround was only needed on early chip versions. As before NO_SIPR becomes a static flag of the PMU struct. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-29perf: Power7: Make CPI stack events available in sysfsSukadev Bhattiprolu1-0/+73
A set of Power7 events are often used for Cycles Per Instruction (CPI) stack analysis. Make these events available in sysfs (/sys/devices/cpu/events/) so they can be identified using their symbolic names: perf stat -e 'cpu/PM_CMPLU_STALL_DCACHE_MISS/' /bin/ls Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: linuxppc-dev@ozlabs.org Link: http://lkml.kernel.org/r/20130406164803.GA408@us.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-05-14powerpc/perf: Fix setting of "to" addresses for BHRBMichael Neuling1-1/+30
Currently we only set the "to" address in the branch stack when the CPU explicitly gives us a value. Unfortunately it only does this for XL form branches (eg blr, bctr, bctar) and not I and B form branches (eg b, bc). Fortunately if we read the instruction from memory we can extract the offset of a branch and calculate the target address. This adds a function power_pmu_bhrb_to() to calculate the target/to address of the corresponding I and B form branches. It handles branches in both user and kernel spaces. It also plumbs this into the perf brhb reading code. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc/pmu: Fix order of interpreting BHRB target entriesMichael Neuling1-43/+46
The current Branch History Rolling Buffer (BHRB) code misinterprets the order of entries in the hardware buffer. It assumes that a branch target address will be read _after_ its corresponding branch. In reality the branch target comes before (lower mfbhrb entry) it's corresponding branch. This is a rewrite of the code to take this into account. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc/perf: Move BHRB code into CONFIG_PPC64 regionMichael Neuling1-121/+127
The new Branch History Rolling buffer (BHRB) code is only useful on 64bit processors, so move it into the #ifdef CONFIG_PPC64 region. This avoids code bloat on 32bit systems. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-04-26powerpc/perf: Enable branch stack sampling frameworkAnshuman Khandual1-3/+164
Provides basic enablement for perf branch stack sampling framework on POWER8 processor based platforms. Adds new BHRB related elements into cpu_hw_event structure to represent current BHRB config, BHRB filter configuration, manage context and to hold output BHRB buffer during PMU interrupt before passing to the user space. This also enables processing of BHRB data and converts them into generic perf branch stack data format. Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-04-26powerpc/perf: Define BHRB generic functions, data and flags for POWER8Anshuman Khandual1-1/+56
This patch populates BHRB specific data for power_pmu structure. It also implements POWER8 specific BHRB filter and configuration functions. Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-04-26powerpc/perf: Add basic assembly code to read BHRB entries on POWER8Anshuman Khandual2-1/+45
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>
2013-04-26powerpc/perf: Power8 PMU supportMichael Ellerman2-1/+539
This patch adds support for the power8 PMU to perf. Work is ongoing to add generic cache events. 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>
2013-04-26powerpc/perf: Add support for SIERMichael Ellerman1-0/+19
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>
2013-04-26powerpc/perf: Add regs_no_sipr()Michael Ellerman1-3/+12
On power8 the presence or absence of SIPR depends on settings at runtime, so convert to using a dynamic flag for NO_SIPR. Existing backends that set NO_SIPR unconditionally set the dynamic flag obviously. 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>
2013-04-26powerpc/perf: Add an accessor for regs->resultMichael Ellerman1-2/+7
Add an accessor for regs->result so we can use it to store more flags in future. 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>
2013-04-26powerpc/perf: Convert mmcra_sipr/sihv() to regs_sipr/sihv()Michael Ellerman1-9/+11
On power8 the SIPR and SIHV are not in MMCRA, so convert the routines to take regs and change the names accordingly. 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>
2013-04-26powerpc/perf: Add an explict flag indicating presence of SLOT fieldMichael Ellerman3-2/+4
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>
2013-03-18Merge tag 'perf-urgent-for-mingo' of ↵Ingo Molnar1-0/+13
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/urgent fixes from Arnaldo Carvalho de Melo: . perf probe: Fix segfault due to testing the wrong pointer for NULL, from Ananth N Mavinakayanahalli. . libtraceevent: Remove hard coded include to /usr/local/include in Makefile, which causes cross builds to include host header files, fix from Jack Mitchell. . perf record: Use the right target interface for synthesizing threads when --cpu/-C option is used, fix from Jiri Olsa. . Check if -DFORTIFY_SOURCE=2 is allowed, as gcc 4.7.2 defines it and then the build is broken when it is redefined in perf, fix from Marcin Slusarz. . Fix build with NO_NEWT=1, that can happen explicitely or when the newt-devel package is not installed, from Michael Ellerman. . perf/POWER7: Create a sysfs format entry for Power7 events, missing patch from a patchseries already merged, from Sukadev Bhattiprolu. . Fix LIBNUMA build with glibc 2.12 and older, from Vinson Lee. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-03-14perf/POWER7: Create a sysfs format entry for Power7 eventsSukadev Bhattiprolu1-0/+13
Create a sysfs entry, '/sys/bus/event_source/devices/cpu/format/event' which describes the format of the POWER7 PMU events. This code is based on corresponding code in x86. Changelog[v4]: [Michael Ellerman, Paul Mckerras] The event format is different for other POWER cpus. So move the code to POWER7-specific, power7-pmu.c Also, the POWER7 format uses bits 0-19 not 0-20. Changelog[v2]: [Jiri Osla] Use PMU_FORMAT_ATTR rather than duplicating code. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Tested-by: Michael Ellerman <michael@ellerman.id.au> 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: Michael Ellerman <michael@ellerman.id.au> 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: benh@kernel.crashing.org Cc: linuxppc-dev@ozlabs.org Link: http://lkml.kernel.org/r/20130306054826.GA14627@us.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-02-24Merge branch 'next' of ↵Linus Torvalds2-29/+66
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 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 ...
2013-01-31perf/POWER7: Make some POWER7 events available in sysfsSukadev Bhattiprolu1-0/+18
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>
2013-01-31perf/POWER7: Make generic event translations available in sysfsSukadev Bhattiprolu2-0/+46
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 a47473939db20e3961b200eb00acf5fcf084d755 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>
2013-01-31perf/Power7: Use macros to identify perf eventsSukadev Bhattiprolu1-8/+20
Define and use macros to identify perf events codes This would make it easier and more readable when these event codes need to be used in more than one place. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Acked-by: Jiri Olsa <jolsa@redhat.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/20130123062353.GB13720@us.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-01-29perf/Power: PERF_EVENT_IOC_ENABLE does not reenable eventsukadev@linux.vnet.ibm.com1-0/+8
perf/Power: PERF_EVENT_IOC_ENABLE does not reenable event If we disable a perf event because we exceeded the specified ->event_limit, power_pmu_stop() sets the PERF_HES_STOPPED flag on the event. If the application then re-enables the event using PERF_EVENT_IOC_ENABLE ioctl, we don't ever clear this STOPPED flag. Consequently, the user space is never notified of the event. Following message has more background and test case. http://lists.eecs.utk.edu/pipermail/ptools-perfapi/2012-October/002528.html Used the following test cases to verify that this patch works on latest PAPI. $ papi.git/src/ctests/nonthread PAPI_TOT_CYC@5000000 $ papi.git/src/ctests/overflow_single_event Changelog[v2]: - [Paul Mackerras] Also clear PERF_HES_UPTODATE flag since we are restarting the event; cleanup comments and patch description. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-10powerpc/perf: Fix for PMCs not making progressMichael Neuling1-0/+2
On POWER7 when we have really small counts left before overflow, we can take a PMU IRQ, but the PMC gets wound back to just before the overflow. If the kernel is setting the PMC to a value just before the overflow, we can get interrupted again without the PMC making any progress (ie another buggy overflow). In this case, we can end up making no forward progress, with the PMC interrupt returning us to the same count over and over. The below detects when we are making no forward progress (ie. delta = 0) and then increases the amount left before the overflow. This stops us from locking up. Signed-off-by: Michael Neuling <mikey@neuling.org> Reviewed-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> cc: Paul Mackerras <paulus@samba.org> cc: Anton Blanchard <anton@samba.org> cc: Linux PPC dev <linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-10powerpc/perf: Fix finding overflowed PMC in interruptMichael Neuling1-29/+54
If a PMC is about to overflow on a counter that's on an active perf event (ie. less than 256 from the end) and a _different_ PMC overflows just at this time (a PMC that's not on an active perf event), we currently mark the event as found, but in reality it's not as it's likely the other PMC that caused the IRQ. Since we mark it as found the second catch all for overflows doesn't run, and we don't reset the overflowing PMC ever. Hence we keep hitting that same PMC IRQ over and over and don't reset the actual overflowing counter. This is a rewrite of the perf interrupt handler for book3s to get around this. We now check to see if any of the PMCs have actually overflowed (ie >= 0x80000000). If yes, record it for active counters and just reset it for inactive counters. If it's not overflowed, then we check to see if it's one of the buggy power7 counters and if it is, record it and continue. If none of the PMCs match this, then we make note that we couldn't find the PMC that caused the IRQ. Signed-off-by: Michael Neuling <mikey@neuling.org> Reviewed-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> cc: Paul Mackerras <paulus@samba.org> cc: Anton Blanchard <anton@samba.org> cc: Linux PPC dev <linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>