// SPDX-License-Identifier: GPL-2.0-or-later/* *  arch/powerpc/kernel/pmc.c * *  Copyright (C) 2004 David Gibson, IBM Corporation. *  Includes code formerly from arch/ppc/kernel/perfmon.c: *    Author: Andy Fleming *    Copyright (c) 2004 Freescale Semiconductor, Inc */ #include <linux/errno.h>#include <linux/bug.h>#include <linux/spinlock.h>#include <linux/export.h> #include <asm/processor.h>#include <asm/cputable.h>#include <asm/pmc.h> #ifndef MMCR0_PMAO#define MMCR0_PMAO	0#endif static void dummy_perf(struct pt_regs *regs){#if defined(CONFIG_FSL_EMB_PERFMON)	mtpmr(PMRN_PMGC0, mfpmr(PMRN_PMGC0) & ~PMGC0_PMIE);#elif defined(CONFIG_PPC64) || defined(CONFIG_PPC_BOOK3S_32)	if (cur_cpu_spec->pmc_type == PPC_PMC_IBM)		mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~(MMCR0_PMXE|MMCR0_PMAO));#else	mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~MMCR0_PMXE);#endif}  static DEFINE_RAW_SPINLOCK(pmc_owner_lock);static void *pmc_owner_caller; /* mostly for debugging */perf_irq_t perf_irq = dummy_perf; int reserve_pmc_hardware(perf_irq_t new_perf_irq){	int err = 0; 	raw_spin_lock(&pmc_owner_lock); 	if (pmc_owner_caller) {		printk(KERN_WARNING "reserve_pmc_hardware: "		       "PMC hardware busy (reserved by caller %p)\n",		       pmc_owner_caller);		err = -EBUSY;		goto out;	} 	pmc_owner_caller = __builtin_return_address(0);	perf_irq = new_perf_irq ? new_perf_irq : dummy_perf;  out:	raw_spin_unlock(&pmc_owner_lock);	return err;}EXPORT_SYMBOL_GPL(reserve_pmc_hardware); void release_pmc_hardware(void){	raw_spin_lock(&pmc_owner_lock); 	WARN_ON(! pmc_owner_caller); 	pmc_owner_caller = NULL;	perf_irq = dummy_perf; 	raw_spin_unlock(&pmc_owner_lock);}EXPORT_SYMBOL_GPL(release_pmc_hardware); #ifdef CONFIG_PPC_BOOK3S_64void power4_enable_pmcs(void){	unsigned long hid0; 	hid0 = mfspr(SPRN_HID0);	hid0 |= 1UL << (63 - 20); 	/* POWER4 requires the following sequence */	asm volatile(		"sync\n"		"mtspr     %1, %0\n"		"mfspr     %0, %1\n"		"mfspr     %0, %1\n"		"mfspr     %0, %1\n"		"mfspr     %0, %1\n"		"mfspr     %0, %1\n"		"mfspr     %0, %1\n"		"isync" : "=&r" (hid0) : "i" (SPRN_HID0), "0" (hid0):		"memory");}#endif /* CONFIG_PPC64 */