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From: Ekansh Gupta <quic_ekangupt@quicinc.com>
To: <srinivas.kandagatla@linaro.org>, <linux-arm-msm@vger.kernel.org>
CC: <gregkh@linuxfoundation.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH v1 5/5] misc: fastrpc: Add static PD restart support
Date: Wed, 8 May 2024 11:12:48 +0530
Message-ID: <20240508054250.2922-6-quic_ekangupt@quicinc.com>
In-Reply-To: <20240508054250.2922-1-quic_ekangupt@quicinc.com>
References: <20240508054250.2922-1-quic_ekangupt@quicinc.com>
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Static PDs on the audio and sensor domains are expected to support
PD restart. The kernel resource handling for the PDs are expected
to be handled by fastrpc driver. For this, there is a requirement
of PD service locator to get the event notifications for static PD
services. Also when events are received, the driver needs to handle
based on PD states. Added changes to add service locator for audio
and sensor domain static PDs and handle the PD restart sequence.

Signed-off-by: Ekansh Gupta <quic_ekangupt@quicinc.com>
---
 drivers/misc/Kconfig   |   1 +
 drivers/misc/fastrpc.c | 226 ++++++++++++++++++++++++++++++++++++++---
 2 files changed, 215 insertions(+), 12 deletions(-)

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 4fb291f0bf7c..0d854da9e85a 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -282,6 +282,7 @@ config QCOM_FASTRPC
 	depends on RPMSG
 	select DMA_SHARED_BUFFER
 	select QCOM_SCM
+	select QCOM_PDR_HELPERS
 	help
 	  Provides a communication mechanism that allows for clients to
 	  make remote method invocations across processor boundary to
diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 4d4dace17ad3..c37edcc881a5 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -22,6 +22,7 @@
 #include <linux/firmware/qcom/qcom_scm.h>
 #include <uapi/misc/fastrpc.h>
 #include <linux/of_reserved_mem.h>
+#include <linux/soc/qcom/pdr.h>
 
 #define ADSP_DOMAIN_ID (0)
 #define MDSP_DOMAIN_ID (1)
@@ -29,6 +30,7 @@
 #define CDSP_DOMAIN_ID (3)
 #define FASTRPC_DEV_MAX		4 /* adsp, mdsp, slpi, cdsp*/
 #define FASTRPC_MAX_SESSIONS	14
+#define FASTRPC_MAX_SPD		4
 #define FASTRPC_MAX_VMIDS	16
 #define FASTRPC_ALIGN		128
 #define FASTRPC_MAX_FDLIST	16
@@ -105,6 +107,18 @@
 
 #define miscdev_to_fdevice(d) container_of(d, struct fastrpc_device, miscdev)
 
+#define AUDIO_PDR_SERVICE_LOCATION_CLIENT_NAME   "audio_pdr_adsp"
+#define AUDIO_PDR_ADSP_SERVICE_NAME              "avs/audio"
+#define ADSP_AUDIOPD_NAME                        "msm/adsp/audio_pd"
+
+#define SENSORS_PDR_ADSP_SERVICE_LOCATION_CLIENT_NAME   "sensors_pdr_adsp"
+#define SENSORS_PDR_ADSP_SERVICE_NAME              "tms/servreg"
+#define ADSP_SENSORPD_NAME                       "msm/adsp/sensor_pd"
+
+#define SENSORS_PDR_SLPI_SERVICE_LOCATION_CLIENT_NAME "sensors_pdr_slpi"
+#define SENSORS_PDR_SLPI_SERVICE_NAME            SENSORS_PDR_ADSP_SERVICE_NAME
+#define SLPI_SENSORPD_NAME                       "msm/slpi/sensor_pd"
+
 static const char *domains[FASTRPC_DEV_MAX] = { "adsp", "mdsp",
 						"sdsp", "cdsp"};
 struct fastrpc_phy_page {
@@ -260,6 +274,16 @@ struct fastrpc_session_ctx {
 	bool valid;
 };
 
+struct fastrpc_static_pd {
+	char *servloc_name;
+	char *spdname;
+	void *pdrhandle;
+	u64 pdrcount;
+	u64 prevpdrcount;
+	atomic_t ispdup;
+	struct fastrpc_channel_ctx *cctx;
+};
+
 struct fastrpc_channel_ctx {
 	int domain_id;
 	int sesscount;
@@ -267,6 +291,7 @@ struct fastrpc_channel_ctx {
 	struct qcom_scm_vmperm vmperms[FASTRPC_MAX_VMIDS];
 	struct rpmsg_device *rpdev;
 	struct fastrpc_session_ctx session[FASTRPC_MAX_SESSIONS];
+	struct fastrpc_static_pd spd[FASTRPC_MAX_SPD];
 	spinlock_t lock;
 	struct idr ctx_idr;
 	struct list_head users;
@@ -304,6 +329,7 @@ struct fastrpc_user {
 	bool is_secure_dev;
 	bool is_unsigned_pd;
 	bool untrusted_process;
+	char *servloc_name;
 	/* Lock for lists */
 	spinlock_t lock;
 	/* lock for allocations */
@@ -1260,6 +1286,50 @@ static int fastrpc_mmap_remove_ssr(struct fastrpc_channel_ctx *cctx)
 	return 0;
 }
 
+static int fastrpc_get_spd_session(struct fastrpc_channel_ctx *cctx,
+				char *servloc_name)
+{
+	int i, session = -1;
+
+	for (i = 0; i < FASTRPC_MAX_SPD ; i++) {
+		if (!cctx->spd[i].servloc_name)
+			continue;
+		if (!strcmp(servloc_name, cctx->spd[i].servloc_name)) {
+			session = i;
+			break;
+		}
+	}
+
+	return session;
+}
+
+static int fastrpc_mmap_remove_pdr(struct fastrpc_user *fl)
+{
+	int err = 0, session = -1;
+
+	if (!fl)
+		return -EBADF;
+
+	session = fastrpc_get_spd_session(fl->cctx, fl->servloc_name);
+	if (session < 0)
+		return -EUSERS;
+
+	if (atomic_read(&fl->cctx->spd[session].ispdup) == 0)
+		return -ENOTCONN;
+
+	if (fl->cctx->spd[session].pdrcount !=
+		fl->cctx->spd[session].prevpdrcount) {
+		err = fastrpc_mmap_remove_ssr(fl->cctx);
+		if (err)
+			dev_info(&fl->cctx->rpdev->dev,
+				"failed to unmap remote heap (err %d)\n", err);
+		fl->cctx->spd[session].prevpdrcount =
+				fl->cctx->spd[session].pdrcount;
+	}
+
+	return err;
+}
+
 static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
 					      char __user *argp)
 {
@@ -1309,6 +1379,18 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
 		goto err_name;
 	}
 
+	fl->servloc_name = AUDIO_PDR_SERVICE_LOCATION_CLIENT_NAME;
+
+	if (!strcmp(name, "audiopd")) {
+		/*
+		 * Remove any previous mappings in case process is trying
+		 * to reconnect after a PD restart on remote subsystem.
+		 */
+		err = fastrpc_mmap_remove_pdr(fl);
+		if (err)
+			goto err_name;
+	}
+
 	if (!fl->cctx->staticpd_status) {
 		err = fastrpc_remote_heap_alloc(fl, fl->sctx->dev, init.memlen, &buf);
 		if (err)
@@ -1724,6 +1806,13 @@ static int fastrpc_init_attach(struct fastrpc_user *fl, int pd)
 	sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_ATTACH, 1, 0);
 	fl->pd = pd;
 
+	if (pd == SENSORS_PD) {
+		if (fl->cctx->domain_id == ADSP_DOMAIN_ID)
+			fl->servloc_name = SENSORS_PDR_ADSP_SERVICE_LOCATION_CLIENT_NAME;
+		else if (fl->cctx->domain_id == SDSP_DOMAIN_ID)
+			fl->servloc_name = SENSORS_PDR_SLPI_SERVICE_LOCATION_CLIENT_NAME;
+	}
+
 	return fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE,
 				       sc, &args[0]);
 }
@@ -2322,6 +2411,72 @@ static long fastrpc_device_ioctl(struct file *file, unsigned int cmd,
 	return err;
 }
 
+static void fastrpc_notify_users(struct fastrpc_user *user)
+{
+	struct fastrpc_invoke_ctx *ctx;
+
+	spin_lock(&user->lock);
+	list_for_each_entry(ctx, &user->pending, node) {
+		ctx->retval = -EPIPE;
+		complete(&ctx->work);
+	}
+	spin_unlock(&user->lock);
+}
+
+static void fastrpc_notify_pdr_drivers(struct fastrpc_channel_ctx *cctx,
+		char *servloc_name)
+{
+	struct fastrpc_user *fl;
+	unsigned long flags;
+
+	spin_lock_irqsave(&cctx->lock, flags);
+	list_for_each_entry(fl, &cctx->users, user) {
+		if (fl->servloc_name && !strcmp(servloc_name, fl->servloc_name))
+			fastrpc_notify_users(fl);
+	}
+	spin_unlock_irqrestore(&cctx->lock, flags);
+}
+
+static void fastrpc_pdr_cb(int state, char *service_path, void *priv)
+{
+	struct fastrpc_static_pd *spd = (struct fastrpc_static_pd *)priv;
+	struct fastrpc_channel_ctx *cctx;
+	unsigned long flags;
+
+	if (!spd)
+		return;
+
+	cctx = spd->cctx;
+	switch (state) {
+	case SERVREG_SERVICE_STATE_DOWN:
+		dev_info(&cctx->rpdev->dev,
+			"%s: %s (%s) is down for PDR on %s\n",
+			__func__, spd->spdname,
+			spd->servloc_name,
+			domains[cctx->domain_id]);
+		spin_lock_irqsave(&cctx->lock, flags);
+		spd->pdrcount++;
+		atomic_set(&spd->ispdup, 0);
+		spin_unlock_irqrestore(&cctx->lock, flags);
+		if (!strcmp(spd->servloc_name,
+				AUDIO_PDR_SERVICE_LOCATION_CLIENT_NAME))
+			cctx->staticpd_status = false;
+
+		fastrpc_notify_pdr_drivers(cctx, spd->servloc_name);
+		break;
+	case SERVREG_SERVICE_STATE_UP:
+		dev_info(&cctx->rpdev->dev,
+			"%s: %s (%s) is up for PDR on %s\n",
+			__func__, spd->spdname,
+			spd->servloc_name,
+			domains[cctx->domain_id]);
+		atomic_set(&spd->ispdup, 1);
+		break;
+	default:
+		break;
+	}
+}
+
 static const struct file_operations fastrpc_fops = {
 	.open = fastrpc_device_open,
 	.release = fastrpc_device_release,
@@ -2441,6 +2596,39 @@ static int fastrpc_device_register(struct device *dev, struct fastrpc_channel_ct
 	return err;
 }
 
+static int fastrpc_setup_service_locator(struct fastrpc_channel_ctx *cctx, char *client_name,
+			char *service_name, char *service_path, int domain, int spd_session)
+{
+	int err = 0;
+	struct pdr_handle *handle = NULL;
+	struct pdr_service *service = NULL;
+
+	/* Register the service locator's callback function */
+	handle = pdr_handle_alloc(fastrpc_pdr_cb, &cctx->spd[spd_session]);
+	if (IS_ERR(handle)) {
+		err = PTR_ERR(handle);
+		goto bail;
+	}
+	cctx->spd[spd_session].pdrhandle = handle;
+	cctx->spd[spd_session].servloc_name = client_name;
+	cctx->spd[spd_session].spdname = service_path;
+	cctx->spd[spd_session].cctx = cctx;
+	service = pdr_add_lookup(handle, service_name, service_path);
+	if (IS_ERR(service)) {
+		err = PTR_ERR(service);
+		goto bail;
+	}
+	pr_info("fastrpc: %s: pdr_add_lookup enabled for %s (%s, %s)\n",
+		__func__, service_name, client_name, service_path);
+
+bail:
+	if (err) {
+		pr_warn("fastrpc: %s: failed for %s (%s, %s)with err %d\n",
+				__func__, service_name, client_name, service_path, err);
+	}
+	return err;
+}
+
 static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
 {
 	struct device *rdev = &rpdev->dev;
@@ -2519,6 +2707,25 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
 		goto fdev_error;
 	}
 
+	if (domain_id == ADSP_DOMAIN_ID) {
+		err = fastrpc_setup_service_locator(data, AUDIO_PDR_SERVICE_LOCATION_CLIENT_NAME,
+			AUDIO_PDR_ADSP_SERVICE_NAME, ADSP_AUDIOPD_NAME, domain_id, 0);
+		if (err)
+			goto populate_error;
+
+		err = fastrpc_setup_service_locator(data,
+			SENSORS_PDR_ADSP_SERVICE_LOCATION_CLIENT_NAME,
+			SENSORS_PDR_ADSP_SERVICE_NAME, ADSP_SENSORPD_NAME, domain_id, 1);
+		if (err)
+			goto populate_error;
+	} else if (domain_id == SDSP_DOMAIN_ID) {
+		err = fastrpc_setup_service_locator(data,
+			SENSORS_PDR_SLPI_SERVICE_LOCATION_CLIENT_NAME,
+			SENSORS_PDR_SLPI_SERVICE_NAME, SLPI_SENSORPD_NAME, domain_id, 0);
+		if (err)
+			goto populate_error;
+	}
+
 	kref_init(&data->refcount);
 
 	dev_set_drvdata(&rpdev->dev, data);
@@ -2548,18 +2755,6 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
 	return err;
 }
 
-static void fastrpc_notify_users(struct fastrpc_user *user)
-{
-	struct fastrpc_invoke_ctx *ctx;
-
-	spin_lock(&user->lock);
-	list_for_each_entry(ctx, &user->pending, node) {
-		ctx->retval = -EPIPE;
-		complete(&ctx->work);
-	}
-	spin_unlock(&user->lock);
-}
-
 static void fastrpc_rpmsg_remove(struct rpmsg_device *rpdev)
 {
 	struct fastrpc_channel_ctx *cctx = dev_get_drvdata(&rpdev->dev);
@@ -2574,6 +2769,13 @@ static void fastrpc_rpmsg_remove(struct rpmsg_device *rpdev)
 		fastrpc_notify_users(user);
 	spin_unlock_irqrestore(&cctx->lock, flags);
 
+	if (cctx->domain_id == ADSP_DOMAIN_ID) {
+		pdr_handle_release(cctx->spd[0].pdrhandle);
+		pdr_handle_release(cctx->spd[1].pdrhandle);
+	} else if (cctx->domain_id == SDSP_DOMAIN_ID) {
+		pdr_handle_release(cctx->spd[0].pdrhandle);
+	}
+
 	if (cctx->fdevice)
 		misc_deregister(&cctx->fdevice->miscdev);
 
-- 
2.43.0