msm: sysmon: Introduce sysmon_get_reason() for querying failure reasons
The sysmon_get_reason() API queries a subsystem that has crashed for
the reason of the failure and returns it as string. Common code between
this new API and sysmon_send_event() is refactored into sysmon_send_msg().
Change-Id: I1e4fda7794f493ee286346ade7b1e779a43d1e4c
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
diff --git a/arch/arm/mach-msm/sysmon.c b/arch/arm/mach-msm/sysmon.c
index 679393d..1305bd1 100644
--- a/arch/arm/mach-msm/sysmon.c
+++ b/arch/arm/mach-msm/sysmon.c
@@ -27,7 +27,8 @@
#include "hsic_sysmon.h"
#include "sysmon.h"
-#define MAX_MSG_LENGTH 50
+#define TX_BUF_SIZE 50
+#define RX_BUF_SIZE 500
#define TIMEOUT_MS 5000
enum transports {
@@ -40,7 +41,7 @@
struct smd_channel *chan;
bool chan_open;
struct completion resp_ready;
- char rx_buf[MAX_MSG_LENGTH];
+ char rx_buf[RX_BUF_SIZE];
enum transports transport;
};
@@ -60,7 +61,8 @@
[SUBSYS_AFTER_POWERUP] = "after_powerup",
};
-static int sysmon_send_smd(struct sysmon_subsys *ss, char *tx_buf, size_t len)
+static int sysmon_send_smd(struct sysmon_subsys *ss, const char *tx_buf,
+ size_t len)
{
int ret;
@@ -78,7 +80,8 @@
return 0;
}
-static int sysmon_send_hsic(struct sysmon_subsys *ss, char *tx_buf, size_t len)
+static int sysmon_send_hsic(struct sysmon_subsys *ss, const char *tx_buf,
+ size_t len)
{
int ret;
size_t actual_len;
@@ -93,11 +96,46 @@
return ret;
}
+static int sysmon_send_msg(struct sysmon_subsys *ss, const char *tx_buf,
+ size_t len)
+{
+ int ret;
+
+ switch (ss->transport) {
+ case TRANSPORT_SMD:
+ ret = sysmon_send_smd(ss, tx_buf, len);
+ break;
+ case TRANSPORT_HSIC:
+ ret = sysmon_send_hsic(ss, tx_buf, len);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ if (!ret)
+ pr_debug("Received response: %s\n", ss->rx_buf);
+
+ return ret;
+}
+
+/**
+ * sysmon_send_event() - Notify a subsystem of another's state change
+ * @dest_ss: ID of subsystem the notification should be sent to
+ * @event_ss: String name of the subsystem that generated the notification
+ * @notif: ID of the notification type (ex. SUBSYS_BEFORE_SHUTDOWN)
+ *
+ * Returns 0 for success, -EINVAL for invalid destination or notification IDs,
+ * -ENODEV if the transport channel is not open, -ETIMEDOUT if the destination
+ * subsystem does not respond, and -ENOSYS if the destination subsystem
+ * responds, but with something other than an acknowledgement.
+ *
+ * If CONFIG_MSM_SYSMON_COMM is not defined, always return success (0).
+ */
int sysmon_send_event(enum subsys_id dest_ss, const char *event_ss,
enum subsys_notif_type notif)
{
struct sysmon_subsys *ss = &subsys[dest_ss];
- char tx_buf[MAX_MSG_LENGTH];
+ char tx_buf[TX_BUF_SIZE];
int ret;
if (dest_ss < 0 || dest_ss >= SYSMON_NUM_SS ||
@@ -109,24 +147,52 @@
notif_name[notif]);
mutex_lock(&ss->lock);
- switch (ss->transport) {
- case TRANSPORT_SMD:
- ret = sysmon_send_smd(ss, tx_buf, strlen(tx_buf));
- break;
- case TRANSPORT_HSIC:
- ret = sysmon_send_hsic(ss, tx_buf, strlen(tx_buf));
- break;
- default:
- ret = -EINVAL;
- }
+ ret = sysmon_send_msg(ss, tx_buf, strlen(tx_buf));
if (ret)
goto out;
- pr_debug("Received response: %s\n", ss->rx_buf);
if (strncmp(ss->rx_buf, "ssr:ack", ARRAY_SIZE(ss->rx_buf)))
ret = -ENOSYS;
- else
- ret = 0;
+out:
+ mutex_unlock(&ss->lock);
+ return ret;
+}
+
+/**
+ * sysmon_get_reason() - Retrieve failure reason from a subsystem.
+ * @dest_ss: ID of subsystem to query
+ * @buf: Caller-allocated buffer for the returned NUL-terminated reason
+ * @len: Length of @buf
+ *
+ * Returns 0 for success, -EINVAL for an invalid destination, -ENODEV if
+ * the SMD transport channel is not open, -ETIMEDOUT if the destination
+ * subsystem does not respond, and -ENOSYS if the destination subsystem
+ * responds with something unexpected.
+ *
+ * If CONFIG_MSM_SYSMON_COMM is not defined, always return success (0).
+ */
+int sysmon_get_reason(enum subsys_id dest_ss, char *buf, size_t len)
+{
+ struct sysmon_subsys *ss = &subsys[dest_ss];
+ const char tx_buf[] = "ssr:retrieve:sfr";
+ const char expect[] = "ssr:return:";
+ size_t prefix_len = ARRAY_SIZE(expect) - 1;
+ int ret;
+
+ if (dest_ss < 0 || dest_ss >= SYSMON_NUM_SS ||
+ buf == NULL || len == 0)
+ return -EINVAL;
+
+ mutex_lock(&ss->lock);
+ ret = sysmon_send_msg(ss, tx_buf, ARRAY_SIZE(tx_buf));
+ if (ret)
+ goto out;
+
+ if (strncmp(ss->rx_buf, expect, prefix_len)) {
+ ret = -ENOSYS;
+ goto out;
+ }
+ strlcpy(buf, ss->rx_buf + prefix_len, len);
out:
mutex_unlock(&ss->lock);
return ret;
diff --git a/arch/arm/mach-msm/sysmon.h b/arch/arm/mach-msm/sysmon.h
index d014187..77c3329 100644
--- a/arch/arm/mach-msm/sysmon.h
+++ b/arch/arm/mach-msm/sysmon.h
@@ -34,22 +34,10 @@
SYSMON_NUM_SS
};
-/**
- * sysmon_send_event() - Notify a subsystem of another's state change.
- * @dest_ss: ID of subsystem the notification should be sent to.
- * @event_ss: String name of the subsystem that generated the notification.
- * @notif: ID of the notification type (ex. SUBSYS_BEFORE_SHUTDOWN)
- *
- * Returns 0 for success, -EINVAL for invalid destination or notification IDs,
- * -ENODEV if the SMD channel is not open, -ETIMEDOUT if the destination
- * subsystem does not respond, and -ENOSYS if the destination subsystem
- * responds, but with something other than an acknowledgement.
- *
- * If CONFIG_MSM_SYSMON_COMM is not defined, always return success (0).
- */
#ifdef CONFIG_MSM_SYSMON_COMM
int sysmon_send_event(enum subsys_id dest_ss, const char *event_ss,
enum subsys_notif_type notif);
+int sysmon_get_reason(enum subsys_id dest_ss, char *buf, size_t len);
#else
static inline int sysmon_send_event(enum subsys_id dest_ss,
const char *event_ss,
@@ -57,6 +45,11 @@
{
return 0;
}
+static inline int sysmon_get_reason(enum subsys_id dest_ss, char *buf,
+ size_t len)
+{
+ return 0;
+}
#endif
#endif