105988c015
This enables the perf_counter subsystem on 32-bit powerpc. Since we don't have any support for hardware counters on 32-bit powerpc yet, only software counters can be used. Besides selecting HAVE_PERF_COUNTERS for 32-bit powerpc as well as 64-bit, the main thing this does is add an implementation of set_perf_counter_pending(). This needs to arrange for perf_counter_do_pending() to be called when interrupts are enabled. Rather than add code to local_irq_restore as 64-bit does, the 32-bit set_perf_counter_pending() generates an interrupt by setting the decrementer to 1 so that a decrementer interrupt will become pending in 1 or 2 timebase ticks (if a decrementer interrupt isn't already pending). When interrupts are enabled, timer_interrupt() will be called, and some new code in there calls perf_counter_do_pending(). We use a per-cpu array of flags to indicate whether we need to call perf_counter_do_pending() or not. This introduces a couple of new Kconfig symbols: PPC_HAVE_PMU_SUPPORT, which is selected by processor families for which we have hardware PMU support (currently only PPC64), and PPC_PERF_CTRS, which enables the powerpc-specific perf_counter back-end. Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: linuxppc-dev@ozlabs.org Cc: benh@kernel.crashing.org LKML-Reference: <19000.55404.103840.393470@cargo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
106 lines
3.9 KiB
C
106 lines
3.9 KiB
C
/*
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* Performance counter support - PowerPC-specific definitions.
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*
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* Copyright 2008-2009 Paul Mackerras, IBM Corporation.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/types.h>
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#include <asm/hw_irq.h>
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#define MAX_HWCOUNTERS 8
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#define MAX_EVENT_ALTERNATIVES 8
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#define MAX_LIMITED_HWCOUNTERS 2
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/*
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* This struct provides the constants and functions needed to
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* describe the PMU on a particular POWER-family CPU.
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*/
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struct power_pmu {
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int n_counter;
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int max_alternatives;
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u64 add_fields;
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u64 test_adder;
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int (*compute_mmcr)(u64 events[], int n_ev,
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unsigned int hwc[], u64 mmcr[]);
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int (*get_constraint)(u64 event, u64 *mskp, u64 *valp);
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int (*get_alternatives)(u64 event, unsigned int flags,
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u64 alt[]);
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void (*disable_pmc)(unsigned int pmc, u64 mmcr[]);
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int (*limited_pmc_event)(u64 event);
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u32 flags;
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int n_generic;
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int *generic_events;
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int (*cache_events)[PERF_COUNT_HW_CACHE_MAX]
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[PERF_COUNT_HW_CACHE_OP_MAX]
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[PERF_COUNT_HW_CACHE_RESULT_MAX];
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};
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extern struct power_pmu *ppmu;
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/*
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* Values for power_pmu.flags
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*/
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#define PPMU_LIMITED_PMC5_6 1 /* PMC5/6 have limited function */
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#define PPMU_ALT_SIPR 2 /* uses alternate posn for SIPR/HV */
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/*
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* Values for flags to get_alternatives()
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*/
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#define PPMU_LIMITED_PMC_OK 1 /* can put this on a limited PMC */
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#define PPMU_LIMITED_PMC_REQD 2 /* have to put this on a limited PMC */
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#define PPMU_ONLY_COUNT_RUN 4 /* only counting in run state */
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struct pt_regs;
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extern unsigned long perf_misc_flags(struct pt_regs *regs);
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extern unsigned long perf_instruction_pointer(struct pt_regs *regs);
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/*
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* Only override the default definitions in include/linux/perf_counter.h
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* if we have hardware PMU support.
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*/
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#ifdef CONFIG_PPC_PERF_CTRS
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#define perf_misc_flags(regs) perf_misc_flags(regs)
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#endif
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/*
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* The power_pmu.get_constraint function returns a 64-bit value and
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* a 64-bit mask that express the constraints between this event and
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* other events.
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*
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* The value and mask are divided up into (non-overlapping) bitfields
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* of three different types:
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*
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* Select field: this expresses the constraint that some set of bits
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* in MMCR* needs to be set to a specific value for this event. For a
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* select field, the mask contains 1s in every bit of the field, and
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* the value contains a unique value for each possible setting of the
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* MMCR* bits. The constraint checking code will ensure that two events
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* that set the same field in their masks have the same value in their
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* value dwords.
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*
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* Add field: this expresses the constraint that there can be at most
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* N events in a particular class. A field of k bits can be used for
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* N <= 2^(k-1) - 1. The mask has the most significant bit of the field
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* set (and the other bits 0), and the value has only the least significant
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* bit of the field set. In addition, the 'add_fields' and 'test_adder'
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* in the struct power_pmu for this processor come into play. The
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* add_fields value contains 1 in the LSB of the field, and the
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* test_adder contains 2^(k-1) - 1 - N in the field.
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*
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* NAND field: this expresses the constraint that you may not have events
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* in all of a set of classes. (For example, on PPC970, you can't select
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* events from the FPU, ISU and IDU simultaneously, although any two are
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* possible.) For N classes, the field is N+1 bits wide, and each class
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* is assigned one bit from the least-significant N bits. The mask has
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* only the most-significant bit set, and the value has only the bit
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* for the event's class set. The test_adder has the least significant
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* bit set in the field.
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*
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* If an event is not subject to the constraint expressed by a particular
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* field, then it will have 0 in both the mask and value for that field.
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*/
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