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v5.9
 1// SPDX-License-Identifier: GPL-2.0-or-later
 2/*
 3 *  arch/powerpc/kernel/pmc.c
 4 *
 5 *  Copyright (C) 2004 David Gibson, IBM Corporation.
 6 *  Includes code formerly from arch/ppc/kernel/perfmon.c:
 7 *    Author: Andy Fleming
 8 *    Copyright (c) 2004 Freescale Semiconductor, Inc
 
 
 
 
 
 9 */
10
11#include <linux/errno.h>
12#include <linux/bug.h>
13#include <linux/spinlock.h>
14#include <linux/export.h>
15
16#include <asm/processor.h>
17#include <asm/cputable.h>
18#include <asm/pmc.h>
19
20#ifndef MMCR0_PMAO
21#define MMCR0_PMAO	0
22#endif
23
24static void dummy_perf(struct pt_regs *regs)
25{
26#if defined(CONFIG_FSL_EMB_PERFMON)
27	mtpmr(PMRN_PMGC0, mfpmr(PMRN_PMGC0) & ~PMGC0_PMIE);
28#elif defined(CONFIG_PPC64) || defined(CONFIG_PPC_BOOK3S_32)
29	if (cur_cpu_spec->pmc_type == PPC_PMC_IBM)
30		mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~(MMCR0_PMXE|MMCR0_PMAO));
31#else
32	mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~MMCR0_PMXE);
33#endif
34}
35
36
37static DEFINE_RAW_SPINLOCK(pmc_owner_lock);
38static void *pmc_owner_caller; /* mostly for debugging */
39perf_irq_t perf_irq = dummy_perf;
40
41int reserve_pmc_hardware(perf_irq_t new_perf_irq)
42{
43	int err = 0;
44
45	raw_spin_lock(&pmc_owner_lock);
46
47	if (pmc_owner_caller) {
48		printk(KERN_WARNING "reserve_pmc_hardware: "
49		       "PMC hardware busy (reserved by caller %p)\n",
50		       pmc_owner_caller);
51		err = -EBUSY;
52		goto out;
53	}
54
55	pmc_owner_caller = __builtin_return_address(0);
56	perf_irq = new_perf_irq ? new_perf_irq : dummy_perf;
57
58 out:
59	raw_spin_unlock(&pmc_owner_lock);
60	return err;
61}
62EXPORT_SYMBOL_GPL(reserve_pmc_hardware);
63
64void release_pmc_hardware(void)
65{
66	raw_spin_lock(&pmc_owner_lock);
67
68	WARN_ON(! pmc_owner_caller);
69
70	pmc_owner_caller = NULL;
71	perf_irq = dummy_perf;
72
73	raw_spin_unlock(&pmc_owner_lock);
74}
75EXPORT_SYMBOL_GPL(release_pmc_hardware);
76
77#ifdef CONFIG_PPC64
78void power4_enable_pmcs(void)
79{
80	unsigned long hid0;
81
82	hid0 = mfspr(SPRN_HID0);
83	hid0 |= 1UL << (63 - 20);
84
85	/* POWER4 requires the following sequence */
86	asm volatile(
87		"sync\n"
88		"mtspr     %1, %0\n"
89		"mfspr     %0, %1\n"
90		"mfspr     %0, %1\n"
91		"mfspr     %0, %1\n"
92		"mfspr     %0, %1\n"
93		"mfspr     %0, %1\n"
94		"mfspr     %0, %1\n"
95		"isync" : "=&r" (hid0) : "i" (SPRN_HID0), "0" (hid0):
96		"memory");
97}
98#endif /* CONFIG_PPC64 */
v4.17
 
  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/bug.h>
 17#include <linux/spinlock.h>
 18#include <linux/export.h>
 19
 20#include <asm/processor.h>
 21#include <asm/cputable.h>
 22#include <asm/pmc.h>
 23
 24#ifndef MMCR0_PMAO
 25#define MMCR0_PMAO	0
 26#endif
 27
 28static void dummy_perf(struct pt_regs *regs)
 29{
 30#if defined(CONFIG_FSL_EMB_PERFMON)
 31	mtpmr(PMRN_PMGC0, mfpmr(PMRN_PMGC0) & ~PMGC0_PMIE);
 32#elif defined(CONFIG_PPC64) || defined(CONFIG_6xx)
 33	if (cur_cpu_spec->pmc_type == PPC_PMC_IBM)
 34		mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~(MMCR0_PMXE|MMCR0_PMAO));
 35#else
 36	mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~MMCR0_PMXE);
 37#endif
 38}
 39
 40
 41static DEFINE_RAW_SPINLOCK(pmc_owner_lock);
 42static void *pmc_owner_caller; /* mostly for debugging */
 43perf_irq_t perf_irq = dummy_perf;
 44
 45int reserve_pmc_hardware(perf_irq_t new_perf_irq)
 46{
 47	int err = 0;
 48
 49	raw_spin_lock(&pmc_owner_lock);
 50
 51	if (pmc_owner_caller) {
 52		printk(KERN_WARNING "reserve_pmc_hardware: "
 53		       "PMC hardware busy (reserved by caller %p)\n",
 54		       pmc_owner_caller);
 55		err = -EBUSY;
 56		goto out;
 57	}
 58
 59	pmc_owner_caller = __builtin_return_address(0);
 60	perf_irq = new_perf_irq ? new_perf_irq : dummy_perf;
 61
 62 out:
 63	raw_spin_unlock(&pmc_owner_lock);
 64	return err;
 65}
 66EXPORT_SYMBOL_GPL(reserve_pmc_hardware);
 67
 68void release_pmc_hardware(void)
 69{
 70	raw_spin_lock(&pmc_owner_lock);
 71
 72	WARN_ON(! pmc_owner_caller);
 73
 74	pmc_owner_caller = NULL;
 75	perf_irq = dummy_perf;
 76
 77	raw_spin_unlock(&pmc_owner_lock);
 78}
 79EXPORT_SYMBOL_GPL(release_pmc_hardware);
 80
 81#ifdef CONFIG_PPC64
 82void power4_enable_pmcs(void)
 83{
 84	unsigned long hid0;
 85
 86	hid0 = mfspr(SPRN_HID0);
 87	hid0 |= 1UL << (63 - 20);
 88
 89	/* POWER4 requires the following sequence */
 90	asm volatile(
 91		"sync\n"
 92		"mtspr     %1, %0\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		"mfspr     %0, %1\n"
 99		"isync" : "=&r" (hid0) : "i" (SPRN_HID0), "0" (hid0):
100		"memory");
101}
102#endif /* CONFIG_PPC64 */