powerpc/powernv: Fix platform dump interface

This patch is a increamental patch on top of commit af93eec4.
This adds support to resend dump available notification, updates
README file. Alos fixes with few other minor issues.

Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

3 files changed, 38 insertions, 19 deletions

diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 013a696d098a00..554a031dcde807 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -173,6 +173,7 @@ extern int opal_enter_rtas(struct rtas_args *args,
 #define OPAL_SENSOR_READ			88
 #define OPAL_GET_PARAM				89
 #define OPAL_SET_PARAM				90
+#define OPAL_DUMP_RESEND			91
 
 #ifndef __ASSEMBLY__
 
@@ -868,6 +869,7 @@ int64_t opal_dump_init(uint8_t dump_type);
 int64_t opal_dump_info(uint32_t *dump_id, uint32_t *dump_size);
 int64_t opal_dump_read(uint32_t dump_id, uint64_t buffer);
 int64_t opal_dump_ack(uint32_t dump_id);
+int64_t opal_dump_resend_notification(void);
 int64_t opal_get_msg(uint64_t buffer, size_t size);
 int64_t opal_check_completion(uint64_t buffer, size_t size, uint64_t token);
 int64_t opal_sync_host_reboot(void);
diff --git a/arch/powerpc/platforms/powernv/opal-dump.c b/arch/powerpc/platforms/powernv/opal-dump.c
index 646c970a08ca1a..444702769e6eb9 100644
--- a/arch/powerpc/platforms/powernv/opal-dump.c
+++ b/arch/powerpc/platforms/powernv/opal-dump.c
@@ -173,7 +173,7 @@ static int64_t dump_read_info(void)
 }
 
 /*
- * Send acknoledgement to OPAL
+ * Send acknowledgement to OPAL
  */
 static int64_t dump_send_ack(uint32_t dump_id)
 {
@@ -181,7 +181,7 @@ static int64_t dump_send_ack(uint32_t dump_id)
 
 	rc = opal_dump_ack(dump_id);
 	if (rc)
-		pr_warn("%s: Failed to send ack message to ID 0x%x (%d)\n",
+		pr_warn("%s: Failed to send ack to Dump ID 0x%x (%d)\n",
 			__func__, dump_id, rc);
 	return rc;
 }
@@ -214,12 +214,12 @@ static int64_t dump_read_data(void)
 	addr = __pa(list);
 
 	/* Fetch data */
-	rc = OPAL_BUSY;
+	rc = OPAL_BUSY_EVENT;
 	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
 		rc = opal_dump_read(dump_record.id, addr);
-		if (rc == OPAL_BUSY) {
+		if (rc == OPAL_BUSY_EVENT) {
 			opal_poll_events(NULL);
-			mdelay(10);
+			msleep(10);
 		}
 	}
 
@@ -258,11 +258,11 @@ static int extract_dump(void)
 		return rc;
 	}
 	if (rc == OPAL_PARTIAL)
-		pr_info("%s: Partially read dump ID 0x%x\n",
+		pr_info("%s: Platform dump partially read. ID = 0x%x\n",
+			__func__, dump_record.id);
+	else
+		pr_info("%s: New platform dump available. ID = 0x%x\n",
 			__func__, dump_record.id);
-
-	pr_info("%s: New platform dump available. ID = 0x%x\n",
-		__func__, dump_record.id);
 
 	/* Update dump blob */
 	dump_blob.data = (void *)dump_record.buffer;
@@ -291,7 +291,7 @@ static void schedule_extract_dump(void)
  * New dump available notification
  *
  * Once we get notification, we extract dump via OPAL call
- * and then write dump to file.
+ * and then pass dump to userspace via debugfs interface.
  */
 static int dump_event(struct notifier_block *nb,
 		      unsigned long events, void *change)
@@ -317,9 +317,17 @@ static struct notifier_block dump_nb = {
 };
 
 
-/* FIXME: debugfs README message */
+/* debugfs README message */
 static const char readme_msg[] =
-	"This file will be populated shortly..";
+	"Platform dump HOWTO:\n\n"
+	"files:\n"
+	"  dump                  - Binary file, contains actual dump data\n"
+	"  dump_available (r--)  - New dump available notification\n"
+	"                          0 : No dump available\n"
+	"                          1 : New dump available\n"
+	"  dump_control(-w-)     - Dump control file\n"
+	"                          1 : Send acknowledgement (dump copied)\n"
+	"                          2 : Initiate FipS dump\n";
 
 /* debugfs dump_control file operations */
 static ssize_t dump_control_write(struct file *file,
@@ -335,7 +343,7 @@ static ssize_t dump_control_write(struct file *file,
 
 	switch (buf[0]) {
 	case '1':	/* Dump send ack */
-		if(dump_avail) {
+		if (dump_avail) {
 			dump_avail = 0;
 			free_dump_data_buf();
 			dump_send_ack(dump_record.id);
@@ -405,16 +413,24 @@ out:
 
 void __init opal_platform_dump_init(void)
 {
-	int ret;
+	int rc;
+
+	/* debugfs interface */
+	rc = debugfs_dump_init();
+	if (rc) {
+		pr_warn("%s: Failed to create debugfs interface (%d)\n",
+			__func__, rc);
+		return;
+	}
 
 	/* Register for opal notifier */
-	ret = opal_notifier_register(&dump_nb);
-	if (ret) {
+	rc = opal_notifier_register(&dump_nb);
+	if (rc) {
 		pr_warn("%s: Can't register OPAL event notifier (%d)\n",
-			__func__, ret);
+			__func__, rc);
 		return;
 	}
 
-	/* debugfs interface */
-	ret = debugfs_dump_init();
+	/* Request to resend dump available notification */
+	opal_dump_resend_notification();
 }
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
index c4907aae01cb74..81e445f689232d 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -136,3 +136,4 @@ OPAL_CALL(opal_sync_host_reboot,		OPAL_SYNC_HOST_REBOOT);
 OPAL_CALL(opal_sensor_read,			OPAL_SENSOR_READ);
 OPAL_CALL(opal_get_param,                       OPAL_GET_PARAM);
 OPAL_CALL(opal_set_param,                       OPAL_SET_PARAM);
+OPAL_CALL(opal_dump_resend_notification,	OPAL_DUMP_RESEND);