From cb09cff30ad22408eea9b2785555af2d2b0ac1bd Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Mon, 7 Nov 2005 18:43:56 +1100 Subject: [PATCH] [PATCH] ppc64: fix oprofile sample bit handling Oprofile was hardwiring the MMCRA sample bit to 1 but on newer cpus (eg POWER5) we want to vary it based on the group being sampled. Add a temporary workaround until people update their oprofile userspace. Signed-off-by: Anton Blanchard Signed-off-by: Paul Mackerras --- arch/powerpc/oprofile/op_model_power4.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/oprofile/op_model_power4.c b/arch/powerpc/oprofile/op_model_power4.c index 886449315847..c4ee5478427b 100644 --- a/arch/powerpc/oprofile/op_model_power4.c +++ b/arch/powerpc/oprofile/op_model_power4.c @@ -17,6 +17,7 @@ #include #include #include +#include #define dbg(args...) @@ -81,6 +82,26 @@ static void power4_reg_setup(struct op_counter_config *ctr, extern void ppc64_enable_pmcs(void); +/* + * Older CPUs require the MMCRA sample bit to be always set, but newer + * CPUs only want it set for some groups. Eventually we will remove all + * knowledge of this bit in the kernel, oprofile userspace should be + * setting it when required. + * + * In order to keep current installations working we force the bit for + * those older CPUs. Once everyone has updated their oprofile userspace we + * can remove this hack. + */ +static inline int mmcra_must_set_sample(void) +{ + if (__is_processor(PV_POWER4) || __is_processor(PV_POWER4p) || + __is_processor(PV_970) || __is_processor(PV_970FX) || + __is_processor(PV_970MP)) + return 1; + + return 0; +} + static void power4_cpu_setup(void *unused) { unsigned int mmcr0 = mmcr0_val; @@ -98,7 +119,8 @@ static void power4_cpu_setup(void *unused) mtspr(SPRN_MMCR1, mmcr1_val); - mmcra |= MMCRA_SAMPLE_ENABLE; + if (mmcra_must_set_sample()) + mmcra |= MMCRA_SAMPLE_ENABLE; mtspr(SPRN_MMCRA, mmcra); dbg("setup on cpu %d, mmcr0 %lx\n", smp_processor_id(), -- 2.20.1