8e3441ebab
The PMC module is used by perf_events, oprofile and watchdogs. Signed-off-by: Zhigang Lu <zlu@tilera.com> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
121 lines
3.1 KiB
C
121 lines
3.1 KiB
C
/*
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* Copyright 2014 Tilera Corporation. All Rights Reserved.
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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, version 2.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for
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* more details.
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*/
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#include <linux/errno.h>
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#include <linux/spinlock.h>
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#include <linux/module.h>
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#include <linux/atomic.h>
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#include <linux/interrupt.h>
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#include <asm/processor.h>
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#include <asm/pmc.h>
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perf_irq_t perf_irq = NULL;
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int handle_perf_interrupt(struct pt_regs *regs, int fault)
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{
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int retval;
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if (!perf_irq)
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panic("Unexpected PERF_COUNT interrupt %d\n", fault);
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nmi_enter();
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retval = perf_irq(regs, fault);
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nmi_exit();
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return retval;
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}
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/* Reserve PMC hardware if it is available. */
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perf_irq_t reserve_pmc_hardware(perf_irq_t new_perf_irq)
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{
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return cmpxchg(&perf_irq, NULL, new_perf_irq);
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}
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EXPORT_SYMBOL(reserve_pmc_hardware);
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/* Release PMC hardware. */
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void release_pmc_hardware(void)
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{
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perf_irq = NULL;
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}
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EXPORT_SYMBOL(release_pmc_hardware);
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/*
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* Get current overflow status of each performance counter,
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* and auxiliary performance counter.
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*/
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unsigned long
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pmc_get_overflow(void)
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{
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unsigned long status;
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/*
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* merge base+aux into a single vector
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*/
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status = __insn_mfspr(SPR_PERF_COUNT_STS);
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status |= __insn_mfspr(SPR_AUX_PERF_COUNT_STS) << TILE_BASE_COUNTERS;
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return status;
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}
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/*
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* Clear the status bit for the corresponding counter, if written
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* with a one.
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*/
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void
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pmc_ack_overflow(unsigned long status)
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{
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/*
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* clear overflow status by writing ones
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*/
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__insn_mtspr(SPR_PERF_COUNT_STS, status);
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__insn_mtspr(SPR_AUX_PERF_COUNT_STS, status >> TILE_BASE_COUNTERS);
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}
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/*
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* The perf count interrupts are masked and unmasked explicitly,
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* and only here. The normal irq_enable() does not enable them,
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* and irq_disable() does not disable them. That lets these
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* routines drive the perf count interrupts orthogonally.
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*
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* We also mask the perf count interrupts on entry to the perf count
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* interrupt handler in assembly code, and by default unmask them
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* again (with interrupt critical section protection) just before
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* returning from the interrupt. If the perf count handler returns
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* a non-zero error code, then we don't re-enable them before returning.
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*
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* For Pro, we rely on both interrupts being in the same word to update
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* them atomically so we never have one enabled and one disabled.
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*/
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#if CHIP_HAS_SPLIT_INTR_MASK()
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# if INT_PERF_COUNT < 32 || INT_AUX_PERF_COUNT < 32
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# error Fix assumptions about which word PERF_COUNT interrupts are in
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# endif
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#endif
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static inline unsigned long long pmc_mask(void)
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{
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unsigned long long mask = 1ULL << INT_PERF_COUNT;
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mask |= 1ULL << INT_AUX_PERF_COUNT;
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return mask;
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}
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void unmask_pmc_interrupts(void)
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{
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interrupt_mask_reset_mask(pmc_mask());
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}
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void mask_pmc_interrupts(void)
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{
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interrupt_mask_set_mask(pmc_mask());
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}
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