2 * arch/powerpc/kernel/pmc.c
4 * Copyright (C) 2004 David Gibson, IBM Corporation.
5 * Includes code formerly from arch/ppc/kernel/perfmon.c:
7 * Copyright (c) 2004 Freescale Semiconductor, Inc
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.
15 #include <linux/errno.h>
16 #include <linux/spinlock.h>
17 #include <linux/module.h>
19 #include <asm/processor.h>
26 static void dummy_perf(struct pt_regs *regs)
28 #if defined(CONFIG_FSL_BOOKE) && !defined(CONFIG_E200)
29 mtpmr(PMRN_PMGC0, mfpmr(PMRN_PMGC0) & ~PMGC0_PMIE);
30 #elif defined(CONFIG_PPC64) || defined(CONFIG_6xx)
31 mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~(MMCR0_PMXE|MMCR0_PMA0));
33 mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~MMCR0_PMXE);
38 static DEFINE_SPINLOCK(pmc_owner_lock);
39 static void *pmc_owner_caller; /* mostly for debugging */
40 perf_irq_t perf_irq = dummy_perf;
42 int reserve_pmc_hardware(perf_irq_t new_perf_irq)
46 spin_lock(&pmc_owner_lock);
48 if (pmc_owner_caller) {
49 printk(KERN_WARNING "reserve_pmc_hardware: "
50 "PMC hardware busy (reserved by caller %p)\n",
56 pmc_owner_caller = __builtin_return_address(0);
57 perf_irq = new_perf_irq ? new_perf_irq : dummy_perf;
60 spin_unlock(&pmc_owner_lock);
63 EXPORT_SYMBOL_GPL(reserve_pmc_hardware);
65 void release_pmc_hardware(void)
67 spin_lock(&pmc_owner_lock);
69 WARN_ON(! pmc_owner_caller);
71 pmc_owner_caller = NULL;
72 perf_irq = dummy_perf;
74 spin_unlock(&pmc_owner_lock);
76 EXPORT_SYMBOL_GPL(release_pmc_hardware);
79 void power4_enable_pmcs(void)
83 hid0 = mfspr(SPRN_HID0);
84 hid0 |= 1UL << (63 - 20);
86 /* POWER4 requires the following sequence */
96 "isync" : "=&r" (hid0) : "i" (SPRN_HID0), "0" (hid0):
99 #endif /* CONFIG_PPC64 */