[PATCH v9 08/10] drivers: qcom: rpmh: allow requests to be sent asynchronously

From: Raju P L S S S N
Date: Thu May 24 2018 - 05:54:55 EST


From: Lina Iyer <ilina@xxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxx>
Signed-off-by: Raju P.L.S.S.S.N <rplsssn@xxxxxxxxxxxxxx>
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---

Changes in v9:
- Remove EXPORT_SYMBOL
- check to free dynamically allocated request object
- free request object after notifying completion
Changes in v6:
- replace rpmh_client with device *
---
drivers/soc/qcom/rpmh.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++
include/soc/qcom/rpmh.h | 7 +++++++
2 files changed, 59 insertions(+)

diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
index ed96d25..415ad7d 100644
--- a/drivers/soc/qcom/rpmh.c
+++ b/drivers/soc/qcom/rpmh.c
@@ -34,6 +34,7 @@
.cmd = { { 0 } }, \
.completion = q, \
.dev = dev, \
+ .needs_free = false, \
}

/**
@@ -59,6 +60,7 @@ struct cache_req {
* @completion: triggered when request is done
* @dev: the device making the request
* @err: err return from the controller
+ * @needs_free: check to free dynamically allocated request object
*/
struct rpmh_request {
struct tcs_request msg;
@@ -66,6 +68,7 @@ struct rpmh_request {
struct completion *completion;
const struct device *dev;
int err;
+ bool needs_free;
};

/**
@@ -141,6 +144,9 @@ void rpmh_tx_done(const struct tcs_request *msg, int r)
/* Signal the blocking thread we are done */
if (compl)
complete(compl);
+
+ if (rpm_msg->needs_free)
+ kfree(rpm_msg);
}

static struct cache_req *__find_req(struct rpmh_ctrlr *ctrlr, u32 addr)
@@ -248,6 +254,52 @@ static int __rpmh_write(const struct device *dev, enum rpmh_state state,
return ret;
}

+static struct rpmh_request *__get_rpmh_msg_async(enum rpmh_state state,
+ const struct tcs_cmd *cmd,
+ u32 n)
+{
+ struct rpmh_request *req;
+
+ if (!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->needs_free = true;
+
+ return req;
+}
+
+/**
+ * rpmh_write_async: Write a set of RPMH commands
+ *
+ * @dev: The device making the request
+ * @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(const struct device *dev, enum rpmh_state state,
+ const struct tcs_cmd *cmd, u32 n)
+{
+ struct rpmh_request *rpm_msg;
+
+ rpm_msg = __get_rpmh_msg_async(state, cmd, n);
+ if (IS_ERR(rpm_msg))
+ return PTR_ERR(rpm_msg);
+
+ return __rpmh_write(dev, state, rpm_msg);
+}
+
/**
* 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 42e62a0..1161a5c 100644
--- a/include/soc/qcom/rpmh.h
+++ b/include/soc/qcom/rpmh.h
@@ -14,6 +14,9 @@
int rpmh_write(const struct device *dev, enum rpmh_state state,
const struct tcs_cmd *cmd, u32 n);

+int rpmh_write_async(const struct device *dev, enum rpmh_state state,
+ const struct tcs_cmd *cmd, u32 n);
+
int rpmh_flush(const struct device *dev);

int rpmh_invalidate(const struct device *dev);
@@ -24,6 +27,10 @@ static inline int rpmh_write(const struct device *dev, enum rpmh_state state,
const struct tcs_cmd *cmd, u32 n)
{ return -ENODEV; }

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

static inline int rpmh_flush(const struct device *dev)
{ return -ENODEV; }
--
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