From c8cd093a6e9f96ea6b871576fd4e46d7c818bb89 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Mon, 26 Oct 2009 18:50:29 +0000 Subject: powerpc: tracing: Add hypervisor call tracepoints Add hcall_entry and hcall_exit tracepoints. This replaces the inline assembly HCALL_STATS code and converts it to use the new tracepoints. To keep the disabled case as quick as possible, we embed a status word in the TOC so we can get at it with a single load. By doing so we keep the overhead at a minimum. Time taken for a null hcall: No tracepoint code: 135.79 cycles Disabled tracepoints: 137.95 cycles For reference, before this patch enabling HCALL_STATS resulted in a null hcall of 201.44 cycles! Signed-off-by: Anton Blanchard Signed-off-by: Paul Mackerras --- arch/powerpc/platforms/pseries/lpar.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'arch/powerpc/platforms/pseries/lpar.c') diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c index 903eb9eec687..4b7b6e8e32de 100644 --- a/arch/powerpc/platforms/pseries/lpar.c +++ b/arch/powerpc/platforms/pseries/lpar.c @@ -39,6 +39,7 @@ #include #include #include +#include #include "plpar_wrappers.h" #include "pseries.h" @@ -661,3 +662,34 @@ void arch_free_page(struct page *page, int order) EXPORT_SYMBOL(arch_free_page); #endif + +#ifdef CONFIG_TRACEPOINTS +/* + * We optimise our hcall path by placing hcall_tracepoint_refcount + * directly in the TOC so we can check if the hcall tracepoints are + * enabled via a single load. + */ + +/* NB: reg/unreg are called while guarded with the tracepoints_mutex */ +extern long hcall_tracepoint_refcount; + +void hcall_tracepoint_regfunc(void) +{ + hcall_tracepoint_refcount++; +} + +void hcall_tracepoint_unregfunc(void) +{ + hcall_tracepoint_refcount--; +} + +void __trace_hcall_entry(unsigned long opcode) +{ + trace_hcall_entry(opcode); +} + +void __trace_hcall_exit(long opcode, unsigned long retval) +{ + trace_hcall_exit(opcode, retval); +} +#endif -- cgit v1.2.3 From 6f26353ca29e96475208bce673efb6a2c58b73f2 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Mon, 26 Oct 2009 18:51:09 +0000 Subject: powerpc: tracing: Give hypervisor call tracepoints access to arguments While most users of the hcall tracepoints will only want the opcode and return code, some will want all the arguments. To avoid the complexity of using varargs we pass a pointer to the register save area, which contains all the arguments. Signed-off-by: Anton Blanchard Signed-off-by: Paul Mackerras --- arch/powerpc/include/asm/trace.h | 9 ++++---- arch/powerpc/platforms/pseries/hvCall.S | 31 +++++++++++++++++++--------- arch/powerpc/platforms/pseries/hvCall_inst.c | 5 +++-- arch/powerpc/platforms/pseries/lpar.c | 9 ++++---- 4 files changed, 34 insertions(+), 20 deletions(-) (limited to 'arch/powerpc/platforms/pseries/lpar.c') diff --git a/arch/powerpc/include/asm/trace.h b/arch/powerpc/include/asm/trace.h index 9b01c0e43b55..cbe2297d68b6 100644 --- a/arch/powerpc/include/asm/trace.h +++ b/arch/powerpc/include/asm/trace.h @@ -82,9 +82,9 @@ extern void hcall_tracepoint_unregfunc(void); TRACE_EVENT_FN(hcall_entry, - TP_PROTO(unsigned long opcode), + TP_PROTO(unsigned long opcode, unsigned long *args), - TP_ARGS(opcode), + TP_ARGS(opcode, args), TP_STRUCT__entry( __field(unsigned long, opcode) @@ -101,9 +101,10 @@ TRACE_EVENT_FN(hcall_entry, TRACE_EVENT_FN(hcall_exit, - TP_PROTO(unsigned long opcode, unsigned long retval), + TP_PROTO(unsigned long opcode, unsigned long retval, + unsigned long *retbuf), - TP_ARGS(opcode, retval), + TP_ARGS(opcode, retval, retbuf), TP_STRUCT__entry( __field(unsigned long, opcode) diff --git a/arch/powerpc/platforms/pseries/hvCall.S b/arch/powerpc/platforms/pseries/hvCall.S index 01e95ab18d35..383a5d0e9818 100644 --- a/arch/powerpc/platforms/pseries/hvCall.S +++ b/arch/powerpc/platforms/pseries/hvCall.S @@ -30,7 +30,7 @@ hcall_tracepoint_refcount: * in early init (eg when populating the MMU hashtable) by using an * unconditional cpu feature. */ -#define HCALL_INST_PRECALL \ +#define HCALL_INST_PRECALL(FIRST_REG) \ BEGIN_FTR_SECTION; \ b 1f; \ END_FTR_SECTION(0, 1); \ @@ -47,6 +47,7 @@ END_FTR_SECTION(0, 1); \ std r9,STK_PARM(r9)(r1); \ std r10,STK_PARM(r10)(r1); \ std r0,16(r1); \ + addi r4,r1,STK_PARM(FIRST_REG); \ stdu r1,-STACK_FRAME_OVERHEAD(r1); \ bl .__trace_hcall_entry; \ addi r1,r1,STACK_FRAME_OVERHEAD; \ @@ -68,7 +69,7 @@ END_FTR_SECTION(0, 1); \ * in early init (eg when populating the MMU hashtable) by using an * unconditional cpu feature. */ -#define HCALL_INST_POSTCALL \ +#define __HCALL_INST_POSTCALL \ BEGIN_FTR_SECTION; \ b 1f; \ END_FTR_SECTION(0, 1); \ @@ -88,9 +89,19 @@ END_FTR_SECTION(0, 1); \ ld r3,STK_PARM(r3)(r1); \ mtlr r0; \ 1: + +#define HCALL_INST_POSTCALL_NORETS \ + li r5,0; \ + __HCALL_INST_POSTCALL + +#define HCALL_INST_POSTCALL(BUFREG) \ + mr r5,BUFREG; \ + __HCALL_INST_POSTCALL + #else -#define HCALL_INST_PRECALL -#define HCALL_INST_POSTCALL +#define HCALL_INST_PRECALL(FIRST_ARG) +#define HCALL_INST_POSTCALL_NORETS +#define HCALL_INST_POSTCALL(BUFREG) #endif .text @@ -101,11 +112,11 @@ _GLOBAL(plpar_hcall_norets) mfcr r0 stw r0,8(r1) - HCALL_INST_PRECALL + HCALL_INST_PRECALL(r4) HVSC /* invoke the hypervisor */ - HCALL_INST_POSTCALL + HCALL_INST_POSTCALL_NORETS lwz r0,8(r1) mtcrf 0xff,r0 @@ -117,7 +128,7 @@ _GLOBAL(plpar_hcall) mfcr r0 stw r0,8(r1) - HCALL_INST_PRECALL + HCALL_INST_PRECALL(r5) std r4,STK_PARM(r4)(r1) /* Save ret buffer */ @@ -136,7 +147,7 @@ _GLOBAL(plpar_hcall) std r6, 16(r12) std r7, 24(r12) - HCALL_INST_POSTCALL + HCALL_INST_POSTCALL(r12) lwz r0,8(r1) mtcrf 0xff,r0 @@ -183,7 +194,7 @@ _GLOBAL(plpar_hcall9) mfcr r0 stw r0,8(r1) - HCALL_INST_PRECALL + HCALL_INST_PRECALL(r5) std r4,STK_PARM(r4)(r1) /* Save ret buffer */ @@ -211,7 +222,7 @@ _GLOBAL(plpar_hcall9) std r11,56(r12) std r0, 64(r12) - HCALL_INST_POSTCALL + HCALL_INST_POSTCALL(r12) lwz r0,8(r1) mtcrf 0xff,r0 diff --git a/arch/powerpc/platforms/pseries/hvCall_inst.c b/arch/powerpc/platforms/pseries/hvCall_inst.c index e44e1035f133..2f58c71b7259 100644 --- a/arch/powerpc/platforms/pseries/hvCall_inst.c +++ b/arch/powerpc/platforms/pseries/hvCall_inst.c @@ -102,7 +102,7 @@ static const struct file_operations hcall_inst_seq_fops = { #define CPU_NAME_BUF_SIZE 32 -static void probe_hcall_entry(unsigned long opcode) +static void probe_hcall_entry(unsigned long opcode, unsigned long *args) { struct hcall_stats *h; @@ -114,7 +114,8 @@ static void probe_hcall_entry(unsigned long opcode) h->purr_start = mfspr(SPRN_PURR); } -static void probe_hcall_exit(unsigned long opcode, unsigned long retval) +static void probe_hcall_exit(unsigned long opcode, unsigned long retval, + unsigned long *retbuf) { struct hcall_stats *h; diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c index 4b7b6e8e32de..0707653612ba 100644 --- a/arch/powerpc/platforms/pseries/lpar.c +++ b/arch/powerpc/platforms/pseries/lpar.c @@ -683,13 +683,14 @@ void hcall_tracepoint_unregfunc(void) hcall_tracepoint_refcount--; } -void __trace_hcall_entry(unsigned long opcode) +void __trace_hcall_entry(unsigned long opcode, unsigned long *args) { - trace_hcall_entry(opcode); + trace_hcall_entry(opcode, args); } -void __trace_hcall_exit(long opcode, unsigned long retval) +void __trace_hcall_exit(long opcode, unsigned long retval, + unsigned long *retbuf) { - trace_hcall_exit(opcode, retval); + trace_hcall_exit(opcode, retval, retbuf); } #endif -- cgit v1.2.3