Merge branch 'bugzilla-11312' into release
[linux-2.6] / arch / powerpc / kernel / pmc.c
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 */