99 lines
2.1 KiB
C
99 lines
2.1 KiB
C
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// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* arch/powerpc/kernel/pmc.c
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*
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* Copyright (C) 2004 David Gibson, IBM Corporation.
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* Includes code formerly from arch/ppc/kernel/perfmon.c:
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* Author: Andy Fleming
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* Copyright (c) 2004 Freescale Semiconductor, Inc
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*/
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#include <linux/errno.h>
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#include <linux/bug.h>
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#include <linux/spinlock.h>
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#include <linux/export.h>
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#include <asm/processor.h>
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#include <asm/cputable.h>
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#include <asm/pmc.h>
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#ifndef MMCR0_PMAO
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#define MMCR0_PMAO 0
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#endif
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static void dummy_perf(struct pt_regs *regs)
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{
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#if defined(CONFIG_FSL_EMB_PERFMON)
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mtpmr(PMRN_PMGC0, mfpmr(PMRN_PMGC0) & ~PMGC0_PMIE);
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#elif defined(CONFIG_PPC64) || defined(CONFIG_PPC_BOOK3S_32)
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if (cur_cpu_spec->pmc_type == PPC_PMC_IBM)
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mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~(MMCR0_PMXE|MMCR0_PMAO));
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#else
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mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~MMCR0_PMXE);
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#endif
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}
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static DEFINE_RAW_SPINLOCK(pmc_owner_lock);
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static void *pmc_owner_caller; /* mostly for debugging */
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perf_irq_t perf_irq = dummy_perf;
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int reserve_pmc_hardware(perf_irq_t new_perf_irq)
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{
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int err = 0;
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raw_spin_lock(&pmc_owner_lock);
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if (pmc_owner_caller) {
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printk(KERN_WARNING "reserve_pmc_hardware: "
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"PMC hardware busy (reserved by caller %p)\n",
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pmc_owner_caller);
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err = -EBUSY;
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goto out;
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}
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pmc_owner_caller = __builtin_return_address(0);
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perf_irq = new_perf_irq ? new_perf_irq : dummy_perf;
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out:
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raw_spin_unlock(&pmc_owner_lock);
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return err;
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}
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EXPORT_SYMBOL_GPL(reserve_pmc_hardware);
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void release_pmc_hardware(void)
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{
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raw_spin_lock(&pmc_owner_lock);
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WARN_ON(! pmc_owner_caller);
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pmc_owner_caller = NULL;
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perf_irq = dummy_perf;
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raw_spin_unlock(&pmc_owner_lock);
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}
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EXPORT_SYMBOL_GPL(release_pmc_hardware);
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#ifdef CONFIG_PPC64
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void power4_enable_pmcs(void)
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{
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unsigned long hid0;
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hid0 = mfspr(SPRN_HID0);
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hid0 |= 1UL << (63 - 20);
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/* POWER4 requires the following sequence */
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asm volatile(
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"sync\n"
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"mtspr %1, %0\n"
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"mfspr %0, %1\n"
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"mfspr %0, %1\n"
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"mfspr %0, %1\n"
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"mfspr %0, %1\n"
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"mfspr %0, %1\n"
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"mfspr %0, %1\n"
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"isync" : "=&r" (hid0) : "i" (SPRN_HID0), "0" (hid0):
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"memory");
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}
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#endif /* CONFIG_PPC64 */
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