[PATCH v5 08/10] drivers: qcom: rpmh: allow requests to be sent asynchronously

Lina Iyer
2018-04-05T16:19:52Z

Platform drivers that want to send a request but do not want to block
until the RPMH request completes have now a new API -
rpmh_write_async().

The API allocates memory and send the requests and returns the control
back to the platform driver. The tx_done callback from the controller is
handled in the context of the controller's thread and frees the
allocated memory. This API allows RPMH requests from atomic contexts as
well.

Signed-off-by: Lina Iyer <ilina@codeaurora.org>
---
drivers/soc/qcom/rpmh.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++
include/soc/qcom/rpmh.h | 8 ++++++++
2 files changed, 61 insertions(+)

diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
index b5468ef082c1..3a96e5f58302 100644
--- a/drivers/soc/qcom/rpmh.c
+++ b/drivers/soc/qcom/rpmh.c
@@ -35,6 +35,7 @@
.cmd = { { 0 } }, \
.completion = q, \
.rc = rc, \
+ .free = NULL, \
}

/**
@@ -59,6 +60,7 @@ struct cache_req {
* @cmd: the payload that will be part of the @msg
* @completion: triggered when request is done
* @err: err return from the controller
+ * @free: the request object to be freed at tx_done
*/
struct rpmh_request {
struct tcs_request msg;
@@ -66,6 +68,7 @@ struct rpmh_request {
struct completion *completion;
struct rpmh_client *rc;
int err;
+ struct rpmh_request *free;
};

/**
@@ -110,6 +113,8 @@ void rpmh_tx_done(const struct tcs_request *msg, int r)
"RPMH TX fail in msg addr=%#x, err=%d\n",
rpm_msg->msg.cmds[0].addr, r);

+ kfree(rpm_msg->free);
+
/* Signal the blocking thread we are done */
if (compl)
complete(compl);
@@ -255,6 +260,54 @@ static int __rpmh_write(struct rpmh_client *rc, enum rpmh_state state,
return ret;
}

+static struct rpmh_request *__get_rpmh_msg_async(struct rpmh_client *rc,
+ enum rpmh_state state,
+ const struct tcs_cmd *cmd,
+ u32 n)
+{
+ struct rpmh_request *req;
+
+ if (IS_ERR_OR_NULL(rc) || !cmd || !n || n > MAX_RPMH_PAYLOAD)
+ return ERR_PTR(-EINVAL);
+
+ req = kzalloc(sizeof(*req), GFP_ATOMIC);
+ if (!req)
+ return ERR_PTR(-ENOMEM);
+
+ memcpy(req->cmd, cmd, n * sizeof(*cmd));
+
+ req->msg.state = state;
+ req->msg.cmds = req->cmd;
+ req->msg.num_cmds = n;
+ req->free = req;
+
+ return req;
+}
+
+/**
+ * rpmh_write_async: Write a set of RPMH commands
+ *
+ * @rc: The RPMh handle got from rpmh_get_client
+ * @state: Active/sleep set
+ * @cmd: The payload data
+ * @n: The number of elements in payload
+ *
+ * Write a set of RPMH commands, the order of commands is maintained
+ * and will be sent as a single shot.
+ */
+int rpmh_write_async(struct rpmh_client *rc, enum rpmh_state state,
+ const struct tcs_cmd *cmd, u32 n)
+{
+ struct rpmh_request *rpm_msg;
+
+ rpm_msg = __get_rpmh_msg_async(rc, state, cmd, n);
+ if (IS_ERR(rpm_msg))
+ return PTR_ERR(rpm_msg);
+
+ return __rpmh_write(rc, state, rpm_msg);
+}
+EXPORT_SYMBOL(rpmh_write_async);
+
/**
* rpmh_write: Write a set of RPMH commands and block until response
*
diff --git a/include/soc/qcom/rpmh.h b/include/soc/qcom/rpmh.h
index 41a2518c46a5..9e6de09e43f0 100644
--- a/include/soc/qcom/rpmh.h
+++ b/include/soc/qcom/rpmh.h
@@ -15,6 +15,9 @@ struct rpmh_client;
int rpmh_write(struct rpmh_client *rc, enum rpmh_state state,
const struct tcs_cmd *cmd, u32 n);

+int rpmh_write_async(struct rpmh_client *rc, enum rpmh_state state,
+ const struct tcs_cmd *cmd, u32 n);
+
struct rpmh_client *rpmh_get_client(struct platform_device *pdev);

int rpmh_flush(struct rpmh_client *rc);
@@ -32,6 +35,11 @@ static inline int rpmh_write(struct rpmh_client *rc, enum rpmh_state state,
static inline struct rpmh_client *rpmh_get_client(struct platform_device *pdev)
{ return ERR_PTR(-ENODEV); }

+static inline int rpmh_write_async(struct rpmh_client *rc,
+ enum rpmh_state state,
+ const struct tcs_cmd *cmd, u32 n)
+{ return -ENODEV; }
+
static inline int rpmh_flush(struct rpmh_client *rc)
{ return -ENODEV; }

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