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/export.h>
   7 #include <linux/init.h>
   8 #include <linux/irq.h>
   9
  10 #include <linux/irq_work.h>
  11 #include <linux/ftrace.h>
  12
  13 #include <asm/pil.h>
  14 #include <asm/pcr.h>
  15 #include <asm/nmi.h>
  16 #include <asm/asi.h>
  17 #include <asm/spitfire.h>
  18
  19 /* This code is shared between various users of the performance
  20  * counters.  Users will be oprofile, pseudo-NMI watchdog, and the
  21  * perf_event support layer.
  22  */
  23
  24 /* Performance counter interrupts run unmasked at PIL level 15.
  25  * Therefore we can't do things like wakeups and other work
  26  * that expects IRQ disabling to be adhered to in locking etc.
  27  *
  28  * Therefore in such situations we defer the work by signalling
  29  * a lower level cpu IRQ.
  30  */
  31 void __irq_entry deferred_pcr_work_irq(int irq, struct pt_regs *regs)
  32 {
  33         struct pt_regs *old_regs;
  34
  35         clear_softint(1 << PIL_DEFERRED_PCR_WORK);
  36
  37         old_regs = set_irq_regs(regs);
  38         irq_enter();
  39 #ifdef CONFIG_IRQ_WORK
  40         irq_work_run();
  41 #endif
  42         irq_exit();
  43         set_irq_regs(old_regs);
  44 }
  45
  46 void arch_irq_work_raise(void)
  47 {
  48         set_softint(1 << PIL_DEFERRED_PCR_WORK);
  49 }
  50
  51 const struct pcr_ops *pcr_ops;
  52 EXPORT_SYMBOL_GPL(pcr_ops);
  53
  54 static u64 direct_pcr_read(unsigned long reg_num)
  55 {
  56         u64 val;
  57
  58         WARN_ON_ONCE(reg_num != 0);
  59         __asm__ __volatile__("rd %%pcr, %0" : "=r" (val));
  60         return val;
  61 }
  62
  63 static void direct_pcr_write(unsigned long reg_num, u64 val)
  64 {
  65         WARN_ON_ONCE(reg_num != 0);
  66         __asm__ __volatile__("wr %0, 0x0, %%pcr" : : "r" (val));
  67 }
  68
  69 static u64 direct_pic_read(unsigned long reg_num)
  70 {
  71         u64 val;
  72
  73         WARN_ON_ONCE(reg_num != 0);
  74         __asm__ __volatile__("rd %%pic, %0" : "=r" (val));
  75         return val;
  76 }
  77
  78 static void direct_pic_write(unsigned long reg_num, u64 val)
  79 {
  80         WARN_ON_ONCE(reg_num != 0);
  81
  82         /* Blackbird errata workaround.  See commentary in
  83          * arch/sparc64/kernel/smp.c:smp_percpu_timer_interrupt()
  84          * for more information.
  85          */
  86         __asm__ __volatile__("ba,pt     %%xcc, 99f\n\t"
  87                              " nop\n\t"
  88                              ".align    64\n"
  89                           "99:wr        %0, 0x0, %%pic\n\t"
  90                              "rd        %%pic, %%g0" : : "r" (val));
  91 }
  92
  93 static u64 direct_picl_value(unsigned int nmi_hz)
  94 {
  95         u32 delta = local_cpu_data().clock_tick / nmi_hz;
  96
  97         return ((u64)((0 - delta) & 0xffffffff)) << 32;
  98 }
  99
 100 static const struct pcr_ops direct_pcr_ops = {
 101         .read_pcr               = direct_pcr_read,
 102         .write_pcr              = direct_pcr_write,
 103         .read_pic               = direct_pic_read,
 104         .write_pic              = direct_pic_write,
 105         .nmi_picl_value         = direct_picl_value,
 106         .pcr_nmi_enable         = (PCR_PIC_PRIV | PCR_STRACE | PCR_UTRACE),
 107         .pcr_nmi_disable        = PCR_PIC_PRIV,
 108 };
 109
 110 static void n2_pcr_write(unsigned long reg_num, u64 val)
 111 {
 112         unsigned long ret;
 113
 114         WARN_ON_ONCE(reg_num != 0);
 115         if (val & PCR_N2_HTRACE) {
 116                 ret = sun4v_niagara2_setperf(HV_N2_PERF_SPARC_CTL, val);
 117                 if (ret != HV_EOK)
 118                         direct_pcr_write(reg_num, val);
 119         } else
 120                 direct_pcr_write(reg_num, val);
 121 }
 122
 123 static u64 n2_picl_value(unsigned int nmi_hz)
 124 {
 125         u32 delta = local_cpu_data().clock_tick / (nmi_hz << 2);
 126
 127         return ((u64)((0 - delta) & 0xffffffff)) << 32;
 128 }
 129
 130 static const struct pcr_ops n2_pcr_ops = {
 131         .read_pcr               = direct_pcr_read,
 132         .write_pcr              = n2_pcr_write,
 133         .read_pic               = direct_pic_read,
 134         .write_pic              = direct_pic_write,
 135         .nmi_picl_value         = n2_picl_value,
 136         .pcr_nmi_enable         = (PCR_PIC_PRIV | PCR_STRACE | PCR_UTRACE |
 137                                    PCR_N2_TOE_OV1 |
 138                                    (2 << PCR_N2_SL1_SHIFT) |
 139                                    (0xff << PCR_N2_MASK1_SHIFT)),
 140         .pcr_nmi_disable        = PCR_PIC_PRIV,
 141 };
 142
 143 static u64 n4_pcr_read(unsigned long reg_num)
 144 {
 145         unsigned long val;
 146
 147         (void) sun4v_vt_get_perfreg(reg_num, &val);
 148
 149         return val;
 150 }
 151
 152 static void n4_pcr_write(unsigned long reg_num, u64 val)
 153 {
 154         (void) sun4v_vt_set_perfreg(reg_num, val);
 155 }
 156
 157 static u64 n4_pic_read(unsigned long reg_num)
 158 {
 159         unsigned long val;
 160
 161         __asm__ __volatile__("ldxa [%1] %2, %0"
 162                              : "=r" (val)
 163                              : "r" (reg_num * 0x8UL), "i" (ASI_PIC));
 164
 165         return val;
 166 }
 167
 168 static void n4_pic_write(unsigned long reg_num, u64 val)
 169 {
 170         __asm__ __volatile__("stxa %0, [%1] %2"
 171                              : /* no outputs */
 172                              : "r" (val), "r" (reg_num * 0x8UL), "i" (ASI_PIC));
 173 }
 174
 175 static u64 n4_picl_value(unsigned int nmi_hz)
 176 {
 177         u32 delta = local_cpu_data().clock_tick / (nmi_hz << 2);
 178
 179         return ((u64)((0 - delta) & 0xffffffff));
 180 }
 181
 182 static const struct pcr_ops n4_pcr_ops = {
 183         .read_pcr               = n4_pcr_read,
 184         .write_pcr              = n4_pcr_write,
 185         .read_pic               = n4_pic_read,
 186         .write_pic              = n4_pic_write,
 187         .nmi_picl_value         = n4_picl_value,
 188         .pcr_nmi_enable         = (PCR_N4_PICNPT | PCR_N4_STRACE |
 189                                    PCR_N4_UTRACE | PCR_N4_TOE |
 190                                    (26 << PCR_N4_SL_SHIFT)),
 191         .pcr_nmi_disable        = PCR_N4_PICNPT,
 192 };
 193
 194 static unsigned long perf_hsvc_group;
 195 static unsigned long perf_hsvc_major;
 196 static unsigned long perf_hsvc_minor;
 197
 198 static int __init register_perf_hsvc(void)
 199 {
 200         if (tlb_type == hypervisor) {
 201                 switch (sun4v_chip_type) {
 202                 case SUN4V_CHIP_NIAGARA1:
 203                         perf_hsvc_group = HV_GRP_NIAG_PERF;
 204                         break;
 205
 206                 case SUN4V_CHIP_NIAGARA2:
 207                         perf_hsvc_group = HV_GRP_N2_CPU;
 208                         break;
 209
 210                 case SUN4V_CHIP_NIAGARA3:
 211                         perf_hsvc_group = HV_GRP_KT_CPU;
 212                         break;
 213
 214                 case SUN4V_CHIP_NIAGARA4:
 215                         perf_hsvc_group = HV_GRP_VT_CPU;
 216                         break;
 217
 218                 default:
 219                         return -ENODEV;
 220                 }
 221
 222
 223                 perf_hsvc_major = 1;
 224                 perf_hsvc_minor = 0;
 225                 if (sun4v_hvapi_register(perf_hsvc_group,
 226                                          perf_hsvc_major,
 227                                          &perf_hsvc_minor)) {
 228                         printk("perfmon: Could not register hvapi.\n");
 229                         return -ENODEV;
 230                 }
 231         }
 232         return 0;
 233 }
 234
 235 static void __init unregister_perf_hsvc(void)
 236 {
 237         if (tlb_type != hypervisor)
 238                 return;
 239         sun4v_hvapi_unregister(perf_hsvc_group);
 240 }
 241
 242 static int __init setup_sun4v_pcr_ops(void)
 243 {
 244         int ret = 0;
 245
 246         switch (sun4v_chip_type) {
 247         case SUN4V_CHIP_NIAGARA1:
 248         case SUN4V_CHIP_NIAGARA2:
 249         case SUN4V_CHIP_NIAGARA3:
 250                 pcr_ops = &n2_pcr_ops;
 251                 break;
 252
 253         case SUN4V_CHIP_NIAGARA4:
 254                 pcr_ops = &n4_pcr_ops;
 255                 break;
 256
 257         default:
 258                 ret = -ENODEV;
 259                 break;
 260         }
 261
 262         return ret;
 263 }
 264
 265 int __init pcr_arch_init(void)
 266 {
 267         int err = register_perf_hsvc();
 268
 269         if (err)
 270                 return err;
 271
 272         switch (tlb_type) {
 273         case hypervisor:
 274                 err = setup_sun4v_pcr_ops();
 275                 if (err)
 276                         goto out_unregister;
 277                 break;
 278
 279         case cheetah:
 280         case cheetah_plus:
 281                 pcr_ops = &direct_pcr_ops;
 282                 break;
 283
 284         case spitfire:
 285                 /* UltraSPARC-I/II and derivatives lack a profile
 286                  * counter overflow interrupt so we can't make use of
 287                  * their hardware currently.
 288                  */
 289                 /* fallthrough */
 290         default:
 291                 err = -ENODEV;
 292                 goto out_unregister;
 293         }
 294
 295         return nmi_init();
 296
 297 out_unregister:
 298         unregister_perf_hsvc();
 299         return err;
 300 }