From a8a3c6d9be83e260279ad4da469fc60a5a05d0fd Mon Sep 17 00:00:00 2001
From: Randall Spangler <rspangler@chromium.org>
Date: Tue, 4 Sep 2012 16:53:33 -0700
Subject: Track amount of stack used for each EC task

BUG=chrome-os-partner:13814
TEST=taskinfo; should show stack used per task
BRANCH=all

Change-Id: Ie40a70a8647c767ea6ec3d164f81c63b62b5008e
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/32590
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
---
 core/cortex-m/task.c | 33 ++++++++++++++++++++++++++++-----
 include/util.h       |  3 +++
 2 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/core/cortex-m/task.c b/core/cortex-m/task.c
index a45e8e0e32..76e6275ec4 100644
--- a/core/cortex-m/task.c
+++ b/core/cortex-m/task.c
@@ -27,12 +27,19 @@ typedef union {
 		uint32_t sp;       /* saved stack pointer for context switch */
 		uint32_t events;   /* bitmaps of received events */
 		uint64_t runtime;  /* Time spent in task */
+		uint32_t reserved; /* Reserved (for padding) */
 		uint32_t guard;    /* Guard value to detect stack overflow */
-		uint8_t stack[0];  /* task stack */
+		uint32_t stack[0]; /* Task stack; must be 64-bit aligned */
 	};
 	uint32_t context[TASK_SIZE/4];
 } task_;
 
+/* Size of stack */
+#define STACK_SIZE (TASK_SIZE - OFFSET_OF(task_, stack))
+
+/* Value to store in unused stack */
+#define STACK_UNUSED_VALUE 0xdeadd00d
+
 /* declare task routine prototypes */
 #define TASK(n, r, d) int r(void *);
 #include TASK_LIST
@@ -502,12 +509,22 @@ void mutex_unlock(struct mutex *mtx)
 void task_print_list(void)
 {
 	int i;
-	ccputs("Task Ready Name         Events      Time (s)\n");
+	ccputs("Task Ready Name         Events      Time (s)  StkUsed\n");
 
 	for (i = 0; i < TASK_ID_COUNT; i++) {
 		char is_ready = (tasks_ready & (1<<i)) ? 'R' : ' ';
-		ccprintf("%4d %c %-16s %08x %11.6ld\n", i, is_ready,
-			 task_names[i], tasks[i].events, tasks[i].runtime);
+		uint32_t *sp;
+
+		int stackused = STACK_SIZE;
+
+		for (sp = tasks[i].stack;
+		     sp < (uint32_t *)tasks[i].sp && *sp == STACK_UNUSED_VALUE;
+		     sp++)
+			stackused -= sizeof(uint32_t);
+
+		ccprintf("%4d %c %-16s %08x %11.6ld  %3d/%3d\n", i, is_ready,
+			 task_names[i], tasks[i].events, tasks[i].runtime,
+			 stackused, STACK_SIZE);
 		if (in_interrupt_context())
 			uart_emergency_flush();
 		else
@@ -581,14 +598,20 @@ int task_pre_init(void)
 
 	/* fill the task memory with initial values */
 	for (i = 0; i < TASK_ID_COUNT; i++) {
+		uint32_t *sp;
+
 		tasks[i].sp = (uint32_t)(tasks + i + 1) - 64;
 		tasks[i].guard = GUARD_VALUE;
-		/* initial context on stack */
+		/* Initial context on stack */
 		tasks[i].context[TASK_SIZE/4 - 8/*r0*/] = tasks_init[i].r0;
 		tasks[i].context[TASK_SIZE/4 - 3/*lr*/] =
 			(uint32_t)task_exit_trap;
 		tasks[i].context[TASK_SIZE/4 - 2/*pc*/] = tasks_init[i].pc;
 		tasks[i].context[TASK_SIZE/4 - 1/*psr*/] = 0x01000000;
+
+		/* Fill unused stack */
+		for (sp = tasks[i].stack; sp < (uint32_t *)tasks[i].sp; sp++)
+			*sp = STACK_UNUSED_VALUE;
 	}
 
 	/* Fill in guard value in scratchpad to prevent stack overflow
diff --git a/include/util.h b/include/util.h
index 2cd15efa65..eca264a3f7 100644
--- a/include/util.h
+++ b/include/util.h
@@ -44,6 +44,9 @@
 #ifndef ARRAY_SIZE
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 #endif
+#ifndef OFFSET_OF
+#define OFFSET_OF(struc, field) ((uint32_t)&(((const struc * const)0)->field))
+#endif
 #ifndef MAX
 #define MAX(a, b) ((a) > (b) ? (a) : (b))
 #endif
-- 
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