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/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 17 /* This code is shared between various users of the performance 18 * counters. Users will be oprofile, pseudo-NMI watchdog, and the 19 * perf_event support layer. 20 */ 21 22 #define PCR_SUN4U_ENABLE (PCR_PIC_PRIV | PCR_STRACE | PCR_UTRACE) 23 #define PCR_N2_ENABLE (PCR_PIC_PRIV | PCR_STRACE | PCR_UTRACE | \ 24 PCR_N2_TOE_OV1 | \ 25 (2 << PCR_N2_SL1_SHIFT) | \ 26 (0xff << PCR_N2_MASK1_SHIFT)) 27 28 u64 pcr_enable; 29 unsigned int picl_shift; 30 31 /* Performance counter interrupts run unmasked at PIL level 15. 32 * Therefore we can't do things like wakeups and other work 33 * that expects IRQ disabling to be adhered to in locking etc. 34 * 35 * Therefore in such situations we defer the work by signalling 36 * a lower level cpu IRQ. 37 */ 38 void __irq_entry deferred_pcr_work_irq(int irq, struct pt_regs *regs) 39 { 40 struct pt_regs *old_regs; 41 42 clear_softint(1 << PIL_DEFERRED_PCR_WORK); 43 44 old_regs = set_irq_regs(regs); 45 irq_enter(); 46 #ifdef CONFIG_IRQ_WORK 47 irq_work_run(); 48 #endif 49 irq_exit(); 50 set_irq_regs(old_regs); 51 } 52 53 void arch_irq_work_raise(void) 54 { 55 set_softint(1 << PIL_DEFERRED_PCR_WORK); 56 } 57 58 const struct pcr_ops *pcr_ops; 59 EXPORT_SYMBOL_GPL(pcr_ops); 60 61 static u64 direct_pcr_read(void) 62 { 63 u64 val; 64 65 read_pcr(val); 66 return val; 67 } 68 69 static void direct_pcr_write(u64 val) 70 { 71 write_pcr(val); 72 } 73 74 static const struct pcr_ops direct_pcr_ops = { 75 .read = direct_pcr_read, 76 .write = direct_pcr_write, 77 }; 78 79 static void n2_pcr_write(u64 val) 80 { 81 unsigned long ret; 82 83 ret = sun4v_niagara2_setperf(HV_N2_PERF_SPARC_CTL, val); 84 if (val != HV_EOK) 85 write_pcr(val); 86 } 87 88 static const struct pcr_ops n2_pcr_ops = { 89 .read = direct_pcr_read, 90 .write = n2_pcr_write, 91 }; 92 93 static unsigned long perf_hsvc_group; 94 static unsigned long perf_hsvc_major; 95 static unsigned long perf_hsvc_minor; 96 97 static int __init register_perf_hsvc(void) 98 { 99 if (tlb_type == hypervisor) { 100 switch (sun4v_chip_type) { 101 case SUN4V_CHIP_NIAGARA1: 102 perf_hsvc_group = HV_GRP_NIAG_PERF; 103 break; 104 105 case SUN4V_CHIP_NIAGARA2: 106 perf_hsvc_group = HV_GRP_N2_CPU; 107 break; 108 109 default: 110 return -ENODEV; 111 } 112 113 114 perf_hsvc_major = 1; 115 perf_hsvc_minor = 0; 116 if (sun4v_hvapi_register(perf_hsvc_group, 117 perf_hsvc_major, 118 &perf_hsvc_minor)) { 119 printk("perfmon: Could not register hvapi.\n"); 120 return -ENODEV; 121 } 122 } 123 return 0; 124 } 125 126 static void __init unregister_perf_hsvc(void) 127 { 128 if (tlb_type != hypervisor) 129 return; 130 sun4v_hvapi_unregister(perf_hsvc_group); 131 } 132 133 int __init pcr_arch_init(void) 134 { 135 int err = register_perf_hsvc(); 136 137 if (err) 138 return err; 139 140 switch (tlb_type) { 141 case hypervisor: 142 pcr_ops = &n2_pcr_ops; 143 pcr_enable = PCR_N2_ENABLE; 144 picl_shift = 2; 145 break; 146 147 case cheetah: 148 case cheetah_plus: 149 pcr_ops = &direct_pcr_ops; 150 pcr_enable = PCR_SUN4U_ENABLE; 151 break; 152 153 case spitfire: 154 /* UltraSPARC-I/II and derivatives lack a profile 155 * counter overflow interrupt so we can't make use of 156 * their hardware currently. 157 */ 158 /* fallthrough */ 159 default: 160 err = -ENODEV; 161 goto out_unregister; 162 } 163 164 return nmi_init(); 165 166 out_unregister: 167 unregister_perf_hsvc(); 168 return err; 169 } 170 171 arch_initcall(pcr_arch_init); 172