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Commit cb09cff3 authored by Anton Blanchard's avatar Anton Blanchard Committed by Paul Mackerras
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[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: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent bcb35576

arch/powerpc/oprofile/op_model_power4.c

+23 −1
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <asm/systemcfg.h>

#include <asm/rtas.h>

#include <asm/oprofile_impl.h>

#include <asm/reg.h>



#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;
@@ -98,6 +119,7 @@ static void power4_cpu_setup(void *unused) 


	mtspr(SPRN_MMCR1, mmcr1_val);



	if (mmcra_must_set_sample())

		mmcra |= MMCRA_SAMPLE_ENABLE;

	mtspr(SPRN_MMCRA, mmcra);