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