1 /* 2 * arch/powerpc/kernel/pmc.c 3 * 4 * Copyright (C) 2004 David Gibson, IBM Corporation. 5 * Includes code formerly from arch/ppc/kernel/perfmon.c: 6 * Author: Andy Fleming 7 * Copyright (c) 2004 Freescale Semiconductor, Inc 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License 11 * as published by the Free Software Foundation; either version 12 * 2 of the License, or (at your option) any later version. 13 */ 14 15 #include <linux/errno.h> 16 #include <linux/spinlock.h> 17 #include <linux/module.h> 18 19 #include <asm/processor.h> 20 #include <asm/cputable.h> 21 #include <asm/pmc.h> 22 23 #ifndef MMCR0_PMAO 24 #define MMCR0_PMAO 0 25 #endif 26 27 static void dummy_perf(struct pt_regs *regs) 28 { 29 #if defined(CONFIG_FSL_EMB_PERFMON) 30 mtpmr(PMRN_PMGC0, mfpmr(PMRN_PMGC0) & ~PMGC0_PMIE); 31 #elif defined(CONFIG_PPC64) || defined(CONFIG_6xx) 32 if (cur_cpu_spec->pmc_type == PPC_PMC_IBM) 33 mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~(MMCR0_PMXE|MMCR0_PMAO)); 34 #else 35 mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~MMCR0_PMXE); 36 #endif 37 } 38 39 40 static DEFINE_SPINLOCK(pmc_owner_lock); 41 static void *pmc_owner_caller; /* mostly for debugging */ 42 perf_irq_t perf_irq = dummy_perf; 43 44 int reserve_pmc_hardware(perf_irq_t new_perf_irq) 45 { 46 int err = 0; 47 48 spin_lock(&pmc_owner_lock); 49 50 if (pmc_owner_caller) { 51 printk(KERN_WARNING "reserve_pmc_hardware: " 52 "PMC hardware busy (reserved by caller %p)\n", 53 pmc_owner_caller); 54 err = -EBUSY; 55 goto out; 56 } 57 58 pmc_owner_caller = __builtin_return_address(0); 59 perf_irq = new_perf_irq ? new_perf_irq : dummy_perf; 60 61 out: 62 spin_unlock(&pmc_owner_lock); 63 return err; 64 } 65 EXPORT_SYMBOL_GPL(reserve_pmc_hardware); 66 67 void release_pmc_hardware(void) 68 { 69 spin_lock(&pmc_owner_lock); 70 71 WARN_ON(! pmc_owner_caller); 72 73 pmc_owner_caller = NULL; 74 perf_irq = dummy_perf; 75 76 spin_unlock(&pmc_owner_lock); 77 } 78 EXPORT_SYMBOL_GPL(release_pmc_hardware); 79 80 #ifdef CONFIG_PPC64 81 void power4_enable_pmcs(void) 82 { 83 unsigned long hid0; 84 85 hid0 = mfspr(SPRN_HID0); 86 hid0 |= 1UL << (63 - 20); 87 88 /* POWER4 requires the following sequence */ 89 asm volatile( 90 "sync\n" 91 "mtspr %1, %0\n" 92 "mfspr %0, %1\n" 93 "mfspr %0, %1\n" 94 "mfspr %0, %1\n" 95 "mfspr %0, %1\n" 96 "mfspr %0, %1\n" 97 "mfspr %0, %1\n" 98 "isync" : "=&r" (hid0) : "i" (SPRN_HID0), "0" (hid0): 99 "memory"); 100 } 101 #endif /* CONFIG_PPC64 */ 102