diff options
| -rw-r--r-- | arch/sparc/oprofile/init.c | 110 |
1 files changed, 109 insertions, 1 deletions
diff --git a/arch/sparc/oprofile/init.c b/arch/sparc/oprofile/init.c index 17bb6035069..e979dcd7772 100644 --- a/arch/sparc/oprofile/init.c +++ b/arch/sparc/oprofile/init.c @@ -12,9 +12,117 @@ #include <linux/errno.h> #include <linux/init.h> +#ifdef CONFIG_SPARC64 +#include <asm/spitfire.h> +#include <asm/cpudata.h> +#include <asm/irq.h> + +static int nmi_enabled; + +static u64 picl_value(void) +{ + u32 delta = local_cpu_data().clock_tick / HZ; + + return (0 - delta) & 0xffffffff; +} + +#define PCR_PIC_PRIV 0x1 /* PIC access is privileged */ +#define PCR_STRACE 0x2 /* Trace supervisor events */ +#define PCR_UTRACE 0x4 /* Trace user events */ + +static void nmi_handler(struct pt_regs *regs) +{ + write_pcr(PCR_PIC_PRIV); + + if (nmi_enabled) { + oprofile_add_sample(regs, 0); + + write_pic(picl_value()); + write_pcr(PCR_PIC_PRIV | PCR_STRACE | PCR_UTRACE); + } +} + +/* We count "clock cycle" events in the lower 32-bit PIC. + * Then configure it such that it overflows every HZ, and thus + * generates a level 15 interrupt at that frequency. + */ +static void cpu_nmi_start(void *_unused) +{ + write_pcr(PCR_PIC_PRIV); + write_pic(picl_value()); + + /* Bit 0: PIC access is privileged + * Bit 1: Supervisor Trace + * Bit 2: User Trace + * + * And the event selection code for cpu cycles is zero. + */ + write_pcr(PCR_PIC_PRIV | PCR_STRACE | PCR_UTRACE); +} + +static void cpu_nmi_stop(void *_unused) +{ + write_pcr(PCR_PIC_PRIV); +} + +static int nmi_start(void) +{ + int err = register_perfctr_intr(nmi_handler); + + if (!err) { + nmi_enabled = 1; + wmb(); + err = on_each_cpu(cpu_nmi_start, NULL, 1); + if (err) { + nmi_enabled = 0; + wmb(); + on_each_cpu(cpu_nmi_stop, NULL, 1); + release_perfctr_intr(nmi_handler); + } + } + + return err; +} + +static void nmi_stop(void) +{ + nmi_enabled = 0; + wmb(); + + on_each_cpu(cpu_nmi_stop, NULL, 1); + release_perfctr_intr(nmi_handler); + synchronize_sched(); +} + +static int oprofile_nmi_init(struct oprofile_operations *ops) +{ + if (tlb_type != cheetah && tlb_type != cheetah_plus) + return -ENODEV; + + ops->create_files = NULL; + ops->setup = NULL; + ops->shutdown = NULL; + ops->start = nmi_start; + ops->stop = nmi_stop; + ops->cpu_type = "timer"; + + printk(KERN_INFO "oprofile: Using perfctr based NMI timer interrupt.\n"); + + return 0; +} +#endif + int __init oprofile_arch_init(struct oprofile_operations *ops) { - return -ENODEV; + int ret = -ENODEV; + +#ifdef CONFIG_SPARC64 + ret = oprofile_nmi_init(ops); + if (!ret) + return ret; +#endif + + return ret; } |