On Mon, Feb 05 2018 at 19:50 +0000, Bjorn Andersson wrote:
On Thu 18 Jan 16:01 PST 2018, Lina Iyer wrote:
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index b7951ce87663..0dba46387f1c 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -11,4 +11,4 @@ obj-$(CONFIG_QCOM_SMP2P) += smp2p.o
obj-$(CONFIG_QCOM_SMSM) += smsm.o
obj-$(CONFIG_QCOM_WCNSS_CTRL) += wcnss_ctrl.o
obj-$(CONFIG_QCOM_COMMAND_DB) += cmd-db.o
-obj-$(CONFIG_QCOM_RPMH) += rpmh-rsc.o
+obj-$(CONFIG_QCOM_RPMH) += rpmh-rsc.o rpmh.o
I think it would be better if you built these two objects into the same
module;
obj-$(CONFIG_QCOM_RPMH) += qcom_rpmh.o
qcom_rpmh-y += rpmh-rsc.o
qcom_rpmh-y += rpmh.o
Curious, how this would be better?
diff --git a/drivers/soc/qcom/rpmh-internal.h b/drivers/soc/qcom/rpmh-internal.h
[..]
diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
[..]
+#define RPMH_TIMEOUT msecs_to_jiffies(10000)
10 * HZ
+
+#define DEFINE_RPMH_MSG_ONSTACK(rc, s, q, c, name) \
+ struct rpmh_msg name = { \
+ .msg = { \
+ .state = s, \
+ .payload = name.cmd, \
+ .num_payload = 0, \
+ .is_complete = true, \
+ .invalidate = false, \
+ }, \
+ .cmd = { { 0 } }, \
+ .completion = q, \
+ .wait_count = c, \
+ .rc = rc, \
+ }
+
+/**
+ * rpmh_msg: the message to be sent to rpmh-rsc
+ *
+ * @msg: the request
+ * @cmd: the payload that will be part of the @msg
+ * @completion: triggered when request is done
+ * @wait_count: count of waiters for this completion
+ * @err: err return from the controller
+ */
+struct rpmh_msg {
struct rpmh_request ?
Hmm.. ok.
+ struct tcs_mbox_msg msg;
+ struct tcs_cmd cmd[MAX_RPMH_PAYLOAD];
+ struct completion *completion;
+ atomic_t *wait_count;
When will @wait_count > 1? As far as I can see the only purpose would be
to be able to control whether you should complete @completion 0 or N
times; but 0 times is covered already by not specifying a @completion.
There is a patch that I haven't posted in this series. It sends a batch
of requests instead of just 1. The wait count is equal to the number of
requests in that batch. Sorry it is a bit ahead of its real use. Adding
it later, increases unnecessary changes in the patches.
+ struct rpmh_client *rc;
+ int err;
+};
+
+/**
+ * rpmh_ctrlr: our representation of the controller
+ *
+ * @drv: the controller instance
+ */
+struct rpmh_ctrlr {
+ struct rsc_drv *drv;
Is this going to grow in the future? Otherwise just drop it and
reference the rsc_drv directly. (Even if it's growing it might be
cleaner to introduce it at that point)
Will grow :)
+};
+
+/**
+ * rpmh_client: the client object
+ *
+ * @dev: the platform device that is the owner
+ * @ctrlr: the controller associated with this client.
+ */
+struct rpmh_client {
+ struct device *dev;
+ struct rpmh_ctrlr *ctrlr;
+};
+
+static struct rpmh_ctrlr rpmh_rsc[RPMH_MAX_MBOXES];
+static DEFINE_MUTEX(rpmh_ctrlr_mutex);
The client needs a reference to the rsc_drv, using the rpmh_ctrlr
abstraction and these global variables only seems to add unnecessary
complexity.
There would be more functionality that needs these as structures and
a list of RSCs and therefore the global mutex and array.
Please bear with me on this.
+
+void rpmh_tx_done(struct tcs_mbox_msg *msg, int r)
+{
+ struct rpmh_msg *rpm_msg = container_of(msg, struct rpmh_msg, msg);
+ atomic_t *wc = rpm_msg->wait_count;
+ struct completion *compl = rpm_msg->completion;
+
+ rpm_msg->err = r;
+
+ if (r)
+ dev_err(rpm_msg->rc->dev,
+ "RPMH TX fail in msg addr 0x%x, err=%d\n",
+ rpm_msg->msg.payload[0].addr, r);
+
+ /* Signal the blocking thread we are done */
+ if (wc && atomic_dec_and_test(wc))
+ if (compl)
+ complete(compl);
I think that you should drop this function and just complete
@rpm_msg->completion in the rcs driver.
I am not sure how much of it I can upstream. Downstream I add more
functionality to this function to make it easier to debug on production.
If its not a bother I would like to keep it as is. Who knows, may be I
can get the debug code upstream.
+}
+EXPORT_SYMBOL(rpmh_tx_done);
+
+/**
+ * wait_for_tx_done: Wait until the response is received.
+ *
+ * @rc: The RPMH client
+ * @compl: The completion object
+ * @addr: An addr that we sent in that request
+ * @data: The data for the address in that request
+ *
+ */
+static inline int wait_for_tx_done(struct rpmh_client *rc,
+ struct completion *compl, u32 addr, u32 data)
+{
+ int ret;
+
+ ret = wait_for_completion_timeout(compl, RPMH_TIMEOUT);
+ if (ret)
+ dev_dbg(rc->dev,
+ "RPMH response received addr=0x%x data=0x%x\n",
+ addr, data);
+ else
+ dev_err(rc->dev,
+ "RPMH response timeout addr=0x%x data=0x%x\n",
+ addr, data);
The request can contain a number of commands and these error messages
ends up printing the first one, on behalf of the client. I suspect that
this isn't useful enough in most cases, causing the client to print
another time.
I therefor suggest that you omit these prints.
On the contrary, just the first address in the request is quite
sufficient to know what request failed. The rest of the requests in
dumped in the FTRACE while sending the request. That is enough to know
what was sent and correlate with what failed.
+
+ return (ret > 0) ? 0 : -ETIMEDOUT;
+}
+
+/**
+ * __rpmh_write: send the RPMH request
+ *
+ * @rc: The RPMH client
+ * @state: Active/Sleep request type
+ * @rpm_msg: The data that needs to be sent (payload).
+ */
+int __rpmh_write(struct rpmh_client *rc, enum rpmh_state state,
+ struct rpmh_msg *rpm_msg)
+{
+ int ret = -EFAULT;
+
+ rpm_msg->msg.state = state;
+
+ if (state == RPMH_ACTIVE_ONLY_STATE) {
+ WARN_ON(irqs_disabled());
+ ret = rpmh_rsc_send_data(rc->ctrlr->drv, &rpm_msg->msg);
+ if (!ret)
+ dev_dbg(rc->dev,
+ "RPMH request sent addr=0x%x, data=0x%x\n",
+ rpm_msg->msg.payload[0].addr,
+ rpm_msg->msg.payload[0].data);
+ else
+ dev_warn(rc->dev,
+ "Error in RPMH request addr=0x%x, data=0x%x\n",
+ rpm_msg->msg.payload[0].addr,
+ rpm_msg->msg.payload[0].data);
Same thing here, for the user to be able to make sense of this error the
client will have to print something with more context. So I think you
should omit these too.
tracing failing addr/data pairs might make sense though!
See explanation above.
+ }
+
+ return ret;
+}
+
+/**
+ * rpmh_write: Write a set of RPMH commands and block until response
+ *
+ * @rc: The RPMh handle got from rpmh_get_dev_channel
+ * @state: Active/sleep set
+ * @cmd: The payload data
+ * @n: The number of elements in payload
+ *
+ * May sleep. Do not call from atomic contexts.
+ */
+int rpmh_write(struct rpmh_client *rc, enum rpmh_state state,
+ struct tcs_cmd *cmd, int n)
+{
+ DECLARE_COMPLETION_ONSTACK(compl);
+ atomic_t wait_count = ATOMIC_INIT(1);
+ DEFINE_RPMH_MSG_ONSTACK(rc, state, &compl, &wait_count, rpm_msg);
+ int ret;
+
+ if (IS_ERR_OR_NULL(rc) || !cmd || n <= 0 || n > MAX_RPMH_PAYLOAD)
+ return -EINVAL;
+
+ might_sleep();
+
+ memcpy(rpm_msg.cmd, cmd, n * sizeof(*cmd));
+ rpm_msg.msg.num_payload = n;
+
+ ret = __rpmh_write(rc, state, &rpm_msg);
+ if (ret)
+ return ret;
+
+ return wait_for_tx_done(rc, &compl, cmd[0].addr, cmd[0].data);
As you're returning here the completion object on the stack will be
trash, so you must inform rpmh_rsc that it may no longer complete it.
I suggest that you provide two functions in the rsc driver;
rpmh_rsc_send_sync() and rpmh_rsc_send_async(), and move the
wait-for-completion into the sync one. Also make the sync one return the
msg->err (and drop the tx_done cross-call).
(Or call them rpmh_rsc_send_wait() and rpmh_rsc_send_nowait())
This is the sync variant. The async variant follows this patch.
The wait_for_tx_done() is blocking and the compl object will not be
trashed until the completion is completed or it fails.
+}
+EXPORT_SYMBOL(rpmh_write);
+
+static struct rpmh_ctrlr *get_rpmh_ctrlr(struct platform_device *pdev)
+{
+ int i;
+ struct rsc_drv *drv = dev_get_drvdata(pdev->dev.parent);
+ struct rpmh_ctrlr *ctrlr = ERR_PTR(-EFAULT);
+
+ if (!drv)
+ return ctrlr;
+
+ mutex_lock(&rpmh_ctrlr_mutex);
+ for (i = 0; i < RPMH_MAX_MBOXES; i++)
+ if (rpmh_rsc[i].drv == drv) {
+ ctrlr = &rpmh_rsc[i];
+ goto unlock;
+ }
+
+ if (i == RPMH_MAX_MBOXES)
+ for (i = 0; i < RPMH_MAX_MBOXES; i++)
+ if (rpmh_rsc[i].drv == NULL) {
+ ctrlr = &rpmh_rsc[i];
+ ctrlr->drv = drv;
+ break;
+ }
I fail to see the reason for tracking rsc_drv references in a global
array and try to find an existing one here. Just return the rsc_drv
acquired from dev_get_drvdata() to the caller.
There are multiple RSCs and clients would refer to one of them.
Future patches add information to the RSC as dictated by the client
(display driver is using the RSC) and therefore take action
accordingly.
+unlock:
+ mutex_unlock(&rpmh_ctrlr_mutex);
+ return ctrlr;
+}
+
+/**
+ * rpmh_get_client: Get the RPMh handle
+ *
+ * @pdev: the platform device which needs to communicate with RPM
+ * accelerators
+ * May sleep.
+ */
+struct rpmh_client *rpmh_get_client(struct platform_device *pdev)
To make this analog to previous rpm drivers I think you should take the
device * of the parent here. I.e. client does:
rpmh = rpmh_get_client(&pdev->dev.parent).
I recognize that this removes the possibility of providing error
messages indicating which client caused the fault, but by above
suggestions these functions would be moved into the rsc driver; or the
error would be propagated to the client which could print these
themselves.
I don't see a particular reason to be analogous with RPM. But, let me
think about it.
+{
+ struct rpmh_client *rc;
+
+ rc = kzalloc(sizeof(*rc), GFP_KERNEL);
+ if (!rc)
+ return ERR_PTR(-ENOMEM);
+
+ rc->dev = &pdev->dev;
+ rc->ctrlr = get_rpmh_ctrlr(pdev);
+ if (IS_ERR(rc->ctrlr)) {
+ kfree(rc);
+ return ERR_PTR(-EFAULT);
+ }
+
+ return rc;
+}
+EXPORT_SYMBOL(rpmh_get_client);
+
+/**
+ * rpmh_release: Release the RPMH client
+ *
+ * @rc: The RPMh handle to be freed.
+ */
+void rpmh_release(struct rpmh_client *rc)
+{
+ kfree(rc);
If you reduce above function to just return a rsc_drv reference you
don't even need a release function, which simplifies clients further.
Hmm.. not sure I understand. I need to release the allocated memory.
+}
+EXPORT_SYMBOL(rpmh_release);
diff --git a/include/soc/qcom/rpmh.h b/include/soc/qcom/rpmh.h
[..]
+struct rpmh_client;
+
+#ifdef CONFIG_QCOM_RPMH
I think it would be fine to just make clients depend on QCOM_RPMH. If
you would prefer to get the compile testing in those drivers then make
this:
#if IS_ENABLED(CONFIG_QCOM_RPMH)
In case someone in the future decides to make RPMH tristate.
OK.
Thanks,
Lina
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