svn commit: r235831 - in head/sys: arm/arm arm/include dev/hwpmc

[Fabien Thomas]

Author: fabient
Date: Wed May 23 13:23:40 2012
New Revision: 235831
URL: http://svn.freebsd.org/changeset/base/235831

Log:
  Soft PMC support for ARM.
  Callgraph is not captured, only current location.
  
  Sample system wide profiling: "pmcstat -Sclock.hard -T"

Modified:
  head/sys/arm/arm/machdep.c
  head/sys/arm/include/pmc_mdep.h
  head/sys/dev/hwpmc/hwpmc_arm.c

Modified: head/sys/arm/arm/machdep.c
==============================================================================
--- head/sys/arm/arm/machdep.c	Wed May 23 13:01:22 2012	(r235830)
+++ head/sys/arm/arm/machdep.c	Wed May 23 13:23:40 2012	(r235831)
@@ -674,9 +674,9 @@ fake_preload_metadata(void)
 	static uint32_t fake_preload[35];
 
 	fake_preload[i++] = MODINFO_NAME;
-	fake_preload[i++] = strlen("elf kernel") + 1;
-	strcpy((char*)&fake_preload[i++], "elf kernel");
-	i += 2;
+	fake_preload[i++] = strlen("kernel") + 1;
+	strcpy((char*)&fake_preload[i++], "kernel");
+	i += 1;
 	fake_preload[i++] = MODINFO_TYPE;
 	fake_preload[i++] = strlen("elf kernel") + 1;
 	strcpy((char*)&fake_preload[i++], "elf kernel");

Modified: head/sys/arm/include/pmc_mdep.h
==============================================================================
--- head/sys/arm/include/pmc_mdep.h	Wed May 23 13:01:22 2012	(r235830)
+++ head/sys/arm/include/pmc_mdep.h	Wed May 23 13:23:40 2012	(r235831)
@@ -54,6 +54,12 @@ union pmc_md_pmc {
 #define	PMC_TRAPFRAME_TO_FP(TF)	((TF)->tf_usr_lr)
 #define	PMC_TRAPFRAME_TO_SP(TF)	((TF)->tf_usr_sp)
 
+/* Build a fake kernel trapframe from current instruction pointer. */
+#define PMC_FAKE_TRAPFRAME(TF)						\
+	do {								\
+	__asm __volatile("mov %0, pc" : "=r" ((TF)->tf_pc));		\
+	} while (0)
+
 /*
  * Prototypes
  */

Modified: head/sys/dev/hwpmc/hwpmc_arm.c
==============================================================================
--- head/sys/dev/hwpmc/hwpmc_arm.c	Wed May 23 13:01:22 2012	(r235830)
+++ head/sys/dev/hwpmc/hwpmc_arm.c	Wed May 23 13:23:40 2012	(r235831)
@@ -38,38 +38,47 @@ __FBSDID("$FreeBSD$");
 struct pmc_mdep *
 pmc_md_initialize()
 {
+#ifdef CPU_XSCALE_IXP425
 	if (cpu_class == CPU_CLASS_XSCALE)
 		return pmc_xscale_initialize();
 	else
+#endif
 		return NULL;
 }
 
 void
 pmc_md_finalize(struct pmc_mdep *md)
 {
+#ifdef CPU_XSCALE_IXP425
 	if (cpu_class == CPU_CLASS_XSCALE)
 		pmc_xscale_finalize(md);
 	else
 		KASSERT(0, ("[arm,%d] Unknown CPU Class 0x%x", __LINE__,
 		    cpu_class));
+#endif
+}
+
+static int
+pmc_save_callchain(uintptr_t *cc, int maxsamples,
+    struct trapframe *tf)
+{
+
+	*cc = PMC_TRAPFRAME_TO_PC(tf);
+	return (1);
 }
 
 int
 pmc_save_kernel_callchain(uintptr_t *cc, int maxsamples,
     struct trapframe *tf)
 {
-	(void) cc;
-	(void) maxsamples;
-	(void) tf;
-	return (0);
+
+	return pmc_save_callchain(cc, maxsamples, tf);
 }
 
 int
 pmc_save_user_callchain(uintptr_t *cc, int maxsamples,
     struct trapframe *tf)
 {
-	(void) cc;
-	(void) maxsamples;
-	(void) tf;
-	return (0);
+
+	return pmc_save_callchain(cc, maxsamples, tf);
 }