[PATCH v6 3/3] soc: qcom: apr: Add avs/audio tracking functionality

Sibi Sankar
2020-03-04T20:09:55Z

Use PDR helper functions to track the protection domains that the apr
services are dependent upon on SDM845 SoC, specifically the "avs/audio"
service running on ADSP Q6.

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
---

V6:
* No change

V5:
* Picked up Bjorn's R-b

drivers/soc/qcom/Kconfig | 1 +
drivers/soc/qcom/apr.c | 123 ++++++++++++++++++++++++++++++++---
include/linux/soc/qcom/apr.h | 1 +
3 files changed, 116 insertions(+), 9 deletions(-)

diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index 945609005cedd..e2c364d86a838 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -201,6 +201,7 @@ config QCOM_APR
tristate "Qualcomm APR Bus (Asynchronous Packet Router)"
depends on ARCH_QCOM || COMPILE_TEST
depends on RPMSG
+ select QCOM_PDR_HELPERS
help
Enable APR IPC protocol support between
application processor and QDSP6. APR is
diff --git a/drivers/soc/qcom/apr.c b/drivers/soc/qcom/apr.c
index 4fcc32420c474..1f35b097c6356 100644
--- a/drivers/soc/qcom/apr.c
+++ b/drivers/soc/qcom/apr.c
@@ -11,6 +11,7 @@
#include <linux/workqueue.h>
#include <linux/of_device.h>
#include <linux/soc/qcom/apr.h>
+#include <linux/soc/qcom/pdr.h>
#include <linux/rpmsg.h>
#include <linux/of.h>

@@ -21,6 +22,7 @@ struct apr {
spinlock_t rx_lock;
struct idr svcs_idr;
int dest_domain_id;
+ struct pdr_handle *pdr;
struct workqueue_struct *rxwq;
struct work_struct rx_work;
struct list_head rx_list;
@@ -289,6 +291,9 @@ static int apr_add_device(struct device *dev, struct device_node *np,
id->svc_id + 1, GFP_ATOMIC);
spin_unlock(&apr->svcs_lock);

+ of_property_read_string_index(np, "qcom,protection-domain",
+ 1, &adev->service_path);
+
dev_info(dev, "Adding APR dev: %s\n", dev_name(&adev->dev));

ret = device_register(&adev->dev);
@@ -300,14 +305,75 @@ static int apr_add_device(struct device *dev, struct device_node *np,
return ret;
}

-static void of_register_apr_devices(struct device *dev)
+static int of_apr_add_pd_lookups(struct device *dev)
+{
+ const char *service_name, *service_path;
+ struct apr *apr = dev_get_drvdata(dev);
+ struct device_node *node;
+ struct pdr_service *pds;
+ int ret;
+
+ for_each_child_of_node(dev->of_node, node) {
+ ret = of_property_read_string_index(node, "qcom,protection-domain",
+ 0, &service_name);
+ if (ret < 0)
+ continue;
+
+ ret = of_property_read_string_index(node, "qcom,protection-domain",
+ 1, &service_path);
+ if (ret < 0) {
+ dev_err(dev, "pdr service path missing: %d\n", ret);
+ return ret;
+ }
+
+ pds = pdr_add_lookup(apr->pdr, service_name, service_path);
+ if (IS_ERR(pds) && PTR_ERR(pds) != -EALREADY) {
+ dev_err(dev, "pdr add lookup failed: %d\n", ret);
+ return PTR_ERR(pds);
+ }
+ }
+
+ return 0;
+}
+
+static void of_register_apr_devices(struct device *dev, const char *svc_path)
{
struct apr *apr = dev_get_drvdata(dev);
struct device_node *node;
+ const char *service_path;
+ int ret;

for_each_child_of_node(dev->of_node, node) {
struct apr_device_id id = { {0} };

+ /*
+ * This function is called with svc_path NULL during
+ * apr_probe(), in which case we register any apr devices
+ * without a qcom,protection-domain specified.
+ *
+ * Then as the protection domains becomes available
+ * (if applicable) this function is again called, but with
+ * svc_path representing the service becoming available. In
+ * this case we register any apr devices with a matching
+ * qcom,protection-domain.
+ */
+
+ ret = of_property_read_string_index(node, "qcom,protection-domain",
+ 1, &service_path);
+ if (svc_path) {
+ /* skip APR services that are PD independent */
+ if (ret)
+ continue;
+
+ /* skip APR services whose PD paths don't match */
+ if (strcmp(service_path, svc_path))
+ continue;
+ } else {
+ /* skip APR services whose PD lookups are registered */
+ if (ret == 0)
+ continue;
+ }
+
if (of_property_read_u32(node, "reg", &id.svc_id))
continue;

@@ -318,6 +384,34 @@ static void of_register_apr_devices(struct device *dev)
}
}

+static int apr_remove_device(struct device *dev, void *svc_path)
+{
+ struct apr_device *adev = to_apr_device(dev);
+
+ if (svc_path && adev->service_path) {
+ if (!strcmp(adev->service_path, (char *)svc_path))
+ device_unregister(&adev->dev);
+ } else {
+ device_unregister(&adev->dev);
+ }
+
+ return 0;
+}
+
+static void apr_pd_status(int state, char *svc_path, void *priv)
+{
+ struct apr *apr = (struct apr *)priv;
+
+ switch (state) {
+ case SERVREG_SERVICE_STATE_UP:
+ of_register_apr_devices(apr->dev, svc_path);
+ break;
+ case SERVREG_SERVICE_STATE_DOWN:
+ device_for_each_child(apr->dev, svc_path, apr_remove_device);
+ break;
+ }
+}
+
static int apr_probe(struct rpmsg_device *rpdev)
{
struct device *dev = &rpdev->dev;
@@ -343,28 +437,39 @@ static int apr_probe(struct rpmsg_device *rpdev)
return -ENOMEM;
}
INIT_WORK(&apr->rx_work, apr_rxwq);
+
+ apr->pdr = pdr_handle_alloc(apr_pd_status, apr);
+ if (IS_ERR(apr->pdr)) {
+ dev_err(dev, "Failed to init PDR handle\n");
+ ret = PTR_ERR(apr->pdr);
+ goto destroy_wq;
+ }
+
INIT_LIST_HEAD(&apr->rx_list);
spin_lock_init(&apr->rx_lock);
spin_lock_init(&apr->svcs_lock);
idr_init(&apr->svcs_idr);
- of_register_apr_devices(dev);
-
- return 0;
-}

-static int apr_remove_device(struct device *dev, void *null)
-{
- struct apr_device *adev = to_apr_device(dev);
+ ret = of_apr_add_pd_lookups(dev);
+ if (ret)
+ goto handle_release;

- device_unregister(&adev->dev);
+ of_register_apr_devices(dev, NULL);

return 0;
+
+handle_release:
+ pdr_handle_release(apr->pdr);
+destroy_wq:
+ destroy_workqueue(apr->rxwq);
+ return ret;
}

static void apr_remove(struct rpmsg_device *rpdev)
{
struct apr *apr = dev_get_drvdata(&rpdev->dev);

+ pdr_handle_release(apr->pdr);
device_for_each_child(&rpdev->dev, NULL, apr_remove_device);
flush_workqueue(apr->rxwq);
destroy_workqueue(apr->rxwq);
diff --git a/include/linux/soc/qcom/apr.h b/include/linux/soc/qcom/apr.h
index c5d52e2cb275f..7f0bc3cf4d610 100644
--- a/include/linux/soc/qcom/apr.h
+++ b/include/linux/soc/qcom/apr.h
@@ -85,6 +85,7 @@ struct apr_device {
uint16_t domain_id;
uint32_t version;
char name[APR_NAME_SIZE];
+ const char *service_path;
spinlock_t lock;
struct list_head node;
};