[PATCH] powerpc: reorg RTAS delay code

This patch attempts to handle RTAS "busy" return codes in a more simple
and consistent manner.  Typical callers of RTAS shouldn't have to
manage wait times and delay calls.

This patch also changes the kernel to use msleep() rather than udelay()
when a runtime delay is necessary.  This will avoid CPU soft lockups
for extended delay conditions.

Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/rtas_flash.c b/arch/powerpc/kernel/rtas_flash.c
index aaf384c..1442b63 100644
--- a/arch/powerpc/kernel/rtas_flash.c
+++ b/arch/powerpc/kernel/rtas_flash.c
@@ -365,20 +365,12 @@
 
 static void manage_flash(struct rtas_manage_flash_t *args_buf)
 {
-	unsigned int wait_time;
 	s32 rc;
 
-	while (1) {
+	do {
 		rc = rtas_call(rtas_token("ibm,manage-flash-image"), 1, 
 			       1, NULL, args_buf->op);
-		if (rc == RTAS_RC_BUSY)
-			udelay(1);
-		else if (rtas_is_extended_busy(rc)) {
-			wait_time = rtas_extended_busy_delay_time(rc);
-			udelay(wait_time * 1000);
-		} else
-			break;
-	}
+	} while (rtas_busy_delay(rc));
 
 	args_buf->status = rc;
 }
@@ -451,27 +443,18 @@
 static void validate_flash(struct rtas_validate_flash_t *args_buf)
 {
 	int token = rtas_token("ibm,validate-flash-image");
-	unsigned int wait_time;
 	int update_results;
 	s32 rc;	
 
 	rc = 0;
-	while(1) {
+	do {
 		spin_lock(&rtas_data_buf_lock);
 		memcpy(rtas_data_buf, args_buf->buf, VALIDATE_BUF_SIZE);
 		rc = rtas_call(token, 2, 2, &update_results, 
 			       (u32) __pa(rtas_data_buf), args_buf->buf_size);
 		memcpy(args_buf->buf, rtas_data_buf, VALIDATE_BUF_SIZE);
 		spin_unlock(&rtas_data_buf_lock);
-			
-		if (rc == RTAS_RC_BUSY)
-			udelay(1);
-		else if (rtas_is_extended_busy(rc)) {
-			wait_time = rtas_extended_busy_delay_time(rc);
-			udelay(wait_time * 1000);
-		} else
-			break;
-	}
+	} while (rtas_busy_delay(rc));
 
 	args_buf->status = rc;
 	args_buf->update_results = update_results;