Commit dc40127c authored by Anton Blanchard's avatar Anton Blanchard Committed by Paul Mackerras
Browse files

[POWERPC] Fix bugs in the hypervisor call stats code 



There were a few issues with the HCALL_STATS code:

- PURR cpu feature checks were backwards
- We iterated one entry off the end of the hcall_stats array
- Remove dead update_hcall_stats() function prototype

I noticed one thing while debugging, and that is we call H_ENTER (to set
up the MMU hashtable in early init) before we have done the cpu fixups.
This means we will execute the PURR SPR reads even on a CPU that isnt
capable of it. I wonder if we can move the CPU feature fixups earlier.

Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent ab87e8dc

arch/powerpc/platforms/pseries/hvCall.S

+3 −3
Original line number Diff line number Diff line
@@ -26,7 +26,7 @@ 
BEGIN_FTR_SECTION;						\

	mfspr	r0,SPRN_PURR;		/* get PURR and */	\

	std	r0,STK_PARM(r6)(r1);	/* save for later */	\

END_FTR_SECTION_IFCLR(CPU_FTR_PURR);

END_FTR_SECTION_IFSET(CPU_FTR_PURR);

	

/*

 * postcall is performed immediately before function return which
@@ -43,7 +43,7 @@ BEGIN_FTR_SECTION; \ 
	mfspr	r8,SPRN_PURR;		/* PURR after */	\

	ld	r6,STK_PARM(r6)(r1);	/* PURR before */	\

	subf	r6,r6,r8;		/* delta */		\

END_FTR_SECTION_IFCLR(CPU_FTR_PURR);				\

END_FTR_SECTION_IFSET(CPU_FTR_PURR);				\

	ld	r5,STK_PARM(r5)(r1);	/* timebase before */	\

	subf	r5,r5,r7;		/* time delta */	\

								\
@@ -66,7 +66,7 @@ BEGIN_FTR_SECTION; \ 
	ld	r7,HCALL_STAT_PURR(r4);	/* PURR */		\

	add	r7,r7,r6;					\

	std	r7,HCALL_STAT_PURR(r4);				\

END_FTR_SECTION_IFCLR(CPU_FTR_PURR);				\

END_FTR_SECTION_IFSET(CPU_FTR_PURR);				\

1:

#else

#define HCALL_INST_PRECALL

arch/powerpc/platforms/pseries/hvCall_inst.c

+2 −2
Original line number Diff line number Diff line
@@ -34,7 +34,7 @@ DEFINE_PER_CPU(struct hcall_stats[HCALL_STAT_ARRAY_SIZE], hcall_stats); 
 */

static void *hc_start(struct seq_file *m, loff_t *pos)

{

	if ((int)*pos < HCALL_STAT_ARRAY_SIZE)

	if ((int)*pos < (HCALL_STAT_ARRAY_SIZE-1))

		return (void *)(unsigned long)(*pos + 1);



	return NULL;
@@ -57,7 +57,7 @@ static int hc_show(struct seq_file *m, void *p) 
	struct hcall_stats *hs = (struct hcall_stats *)m->private;



	if (hs[h_num].num_calls) {

		if (!cpu_has_feature(CPU_FTR_PURR))

		if (cpu_has_feature(CPU_FTR_PURR))

			seq_printf(m, "%lu %lu %lu %lu\n", h_num<<2,

				   hs[h_num].num_calls,

				   hs[h_num].tb_total,

include/asm-powerpc/hvcall.h

+0 −2
Original line number Diff line number Diff line
@@ -252,8 +252,6 @@ struct hcall_stats { 
	unsigned long	tb_total;	/* total wall time (mftb) of calls. */

	unsigned long	purr_total;	/* total cpu time (PURR) of calls. */

};

void update_hcall_stats(unsigned long opcode, unsigned long tb_delta,

			unsigned long purr_delta);

#define HCALL_STAT_ARRAY_SIZE	((MAX_HCALL_OPCODE >> 2) + 1)



#endif /* __ASSEMBLY__ */

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