arch/sparc/kernel/pcr.c

   1 /* pcr.c: Generic sparc64 performance counter infrastructure.
   2  *
   3  * Copyright (C) 2009 David S. Miller (davem@davemloft.net)
   4  */
   5 #include <linux/kernel.h>
   6 #include <linux/module.h>
   7 #include <linux/init.h>
   8 #include <linux/irq.h>
   9
  10 #include <linux/perf_event.h>
  11
  12 #include <asm/pil.h>
  13 #include <asm/pcr.h>
  14 #include <asm/nmi.h>
  15
  16 /* This code is shared between various users of the performance
  17  * counters.  Users will be oprofile, pseudo-NMI watchdog, and the
  18  * perf_event support layer.
  19  */
  20
  21 #define PCR_SUN4U_ENABLE        (PCR_PIC_PRIV | PCR_STRACE | PCR_UTRACE)
  22 #define PCR_N2_ENABLE           (PCR_PIC_PRIV | PCR_STRACE | PCR_UTRACE | \
  23                                  PCR_N2_TOE_OV1 | \
  24                                  (2 << PCR_N2_SL1_SHIFT) | \
  25                                  (0xff << PCR_N2_MASK1_SHIFT))
  26
  27 u64 pcr_enable;
  28 unsigned int picl_shift;
  29
  30 /* Performance counter interrupts run unmasked at PIL level 15.
  31  * Therefore we can't do things like wakeups and other work
  32  * that expects IRQ disabling to be adhered to in locking etc.
  33  *
  34  * Therefore in such situations we defer the work by signalling
  35  * a lower level cpu IRQ.
  36  */
  37 void deferred_pcr_work_irq(int irq, struct pt_regs *regs)
  38 {
  39         struct pt_regs *old_regs;
  40
  41         clear_softint(1 << PIL_DEFERRED_PCR_WORK);
  42
  43         old_regs = set_irq_regs(regs);
  44         irq_enter();
  45 #ifdef CONFIG_PERF_EVENTS
  46         perf_event_do_pending();
  47 #endif
  48         irq_exit();
  49         set_irq_regs(old_regs);
  50 }
  51
  52 void set_perf_event_pending(void)
  53 {
  54         set_softint(1 << PIL_DEFERRED_PCR_WORK);
  55 }
  56
  57 const struct pcr_ops *pcr_ops;
  58 EXPORT_SYMBOL_GPL(pcr_ops);
  59
  60 static u64 direct_pcr_read(void)
  61 {
  62         u64 val;
  63
  64         read_pcr(val);
  65         return val;
  66 }
  67
  68 static void direct_pcr_write(u64 val)
  69 {
  70         write_pcr(val);
  71 }
  72
  73 static const struct pcr_ops direct_pcr_ops = {
  74         .read   = direct_pcr_read,
  75         .write  = direct_pcr_write,
  76 };
  77
  78 static void n2_pcr_write(u64 val)
  79 {
  80         unsigned long ret;
  81
  82         ret = sun4v_niagara2_setperf(HV_N2_PERF_SPARC_CTL, val);
  83         if (val != HV_EOK)
  84                 write_pcr(val);
  85 }
  86
  87 static const struct pcr_ops n2_pcr_ops = {
  88         .read   = direct_pcr_read,
  89         .write  = n2_pcr_write,
  90 };
  91
  92 static unsigned long perf_hsvc_group;
  93 static unsigned long perf_hsvc_major;
  94 static unsigned long perf_hsvc_minor;
  95
  96 static int __init register_perf_hsvc(void)
  97 {
  98         if (tlb_type == hypervisor) {
  99                 switch (sun4v_chip_type) {
 100                 case SUN4V_CHIP_NIAGARA1:
 101                         perf_hsvc_group = HV_GRP_NIAG_PERF;
 102                         break;
 103
 104                 case SUN4V_CHIP_NIAGARA2:
 105                         perf_hsvc_group = HV_GRP_N2_CPU;
 106                         break;
 107
 108                 default:
 109                         return -ENODEV;
 110                 }
 111
 112
 113                 perf_hsvc_major = 1;
 114                 perf_hsvc_minor = 0;
 115                 if (sun4v_hvapi_register(perf_hsvc_group,
 116                                          perf_hsvc_major,
 117                                          &perf_hsvc_minor)) {
 118                         printk("perfmon: Could not register hvapi.\n");
 119                         return -ENODEV;
 120                 }
 121         }
 122         return 0;
 123 }
 124
 125 static void __init unregister_perf_hsvc(void)
 126 {
 127         if (tlb_type != hypervisor)
 128                 return;
 129         sun4v_hvapi_unregister(perf_hsvc_group);
 130 }
 131
 132 int __init pcr_arch_init(void)
 133 {
 134         int err = register_perf_hsvc();
 135
 136         if (err)
 137                 return err;
 138
 139         switch (tlb_type) {
 140         case hypervisor:
 141                 pcr_ops = &n2_pcr_ops;
 142                 pcr_enable = PCR_N2_ENABLE;
 143                 picl_shift = 2;
 144                 break;
 145
 146         case cheetah:
 147         case cheetah_plus:
 148                 pcr_ops = &direct_pcr_ops;
 149                 pcr_enable = PCR_SUN4U_ENABLE;
 150                 break;
 151
 152         case spitfire:
 153                 /* UltraSPARC-I/II and derivatives lack a profile
 154                  * counter overflow interrupt so we can't make use of
 155                  * their hardware currently.
 156                  */
 157                 /* fallthrough */
 158         default:
 159                 err = -ENODEV;
 160                 goto out_unregister;
 161         }
 162
 163         return nmi_init();
 164
 165 out_unregister:
 166         unregister_perf_hsvc();
 167         return err;
 168 }
 169
 170 arch_initcall(pcr_arch_init);