[PATCH 6.19 034/220] firmware: stratix10-svc: Add Multi SVC clients support

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Muhammad Amirul Asyraf Mohamad Jamian <muhammad.amirul.asyraf.mohamad.jamian@altera.com>

[ Upstream commit 22fd7f7fed2ae3702f90d1985c326354e86b9c75 ]

In the current implementation, SVC client drivers such as socfpga-hwmon,
intel_fcs, stratix10-soc, stratix10-rsu each send an SMC command that
triggers a single thread in the stratix10-svc driver. Upon receiving a
callback, the initiating client driver sends a stratix10-svc-done signal,
terminating the thread without waiting for other pending SMC commands to
complete. This leads to a timeout issue in the firmware SVC mailbox service
when multiple client drivers send SMC commands concurrently.

To resolve this issue, a dedicated thread is now created per channel. The
stratix10-svc driver will support up to the number of channels defined by
SVC_NUM_CHANNEL. Thread synchronization is handled using a mutex to prevent
simultaneous issuance of SMC commands by multiple threads.

SVC_NUM_DATA_IN_FIFO is reduced from 32 to 8, since each channel now has
its own dedicated FIFO and the SDM processes commands one at a time.
8 entries per channel is sufficient while keeping the total aggregate
capacity the same (4 channels x 8 = 32 entries).

Additionally, a thread task is now validated before invoking kthread_stop
when the user aborts, ensuring safe termination.

Timeout values have also been adjusted to accommodate the increased load
from concurrent client driver activity.

Fixes: 7ca5ce896524 ("firmware: add Intel Stratix10 service layer driver")
Cc: stable@vger.kernel.org
Signed-off-by: Ang Tien Sung <tien.sung.ang@altera.com>
Signed-off-by: Fong, Yan Kei <yankei.fong@altera.com>
Signed-off-by: Muhammad Amirul Asyraf Mohamad Jamian <muhammad.amirul.asyraf.mohamad.jamian@altera.com>
Link: https://lore.kernel.org/all/20260305093151.2678-1-muhammad.amirul.asyraf.mohamad.jamian@altera.com
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/firmware/stratix10-svc.c                    |  228 +++++++++++---------
 include/linux/firmware/intel/stratix10-svc-client.h |    8 
 2 files changed, 130 insertions(+), 106 deletions(-)

--- a/drivers/firmware/stratix10-svc.c
+++ b/drivers/firmware/stratix10-svc.c
@@ -37,15 +37,14 @@
  * service layer will return error to FPGA manager when timeout occurs,
  * timeout is set to 30 seconds (30 * 1000) at Intel Stratix10 SoC.
  */
-#define SVC_NUM_DATA_IN_FIFO			32
+#define SVC_NUM_DATA_IN_FIFO			8
 #define SVC_NUM_CHANNEL				4
-#define FPGA_CONFIG_DATA_CLAIM_TIMEOUT_MS	200
+#define FPGA_CONFIG_DATA_CLAIM_TIMEOUT_MS	2000
 #define FPGA_CONFIG_STATUS_TIMEOUT_SEC		30
 #define BYTE_TO_WORD_SIZE              4
 
 /* stratix10 service layer clients */
 #define STRATIX10_RSU				"stratix10-rsu"
-#define INTEL_FCS				"intel-fcs"
 
 /* Maximum number of SDM client IDs. */
 #define MAX_SDM_CLIENT_IDS			16
@@ -105,11 +104,9 @@ struct stratix10_svc_chan;
 /**
  * struct stratix10_svc - svc private data
  * @stratix10_svc_rsu: pointer to stratix10 RSU device
- * @intel_svc_fcs: pointer to the FCS device
  */
 struct stratix10_svc {
 	struct platform_device *stratix10_svc_rsu;
-	struct platform_device *intel_svc_fcs;
 };
 
 /**
@@ -251,12 +248,10 @@ struct stratix10_async_ctrl {
  * @num_active_client: number of active service client
  * @node: list management
  * @genpool: memory pool pointing to the memory region
- * @task: pointer to the thread task which handles SMC or HVC call
- * @svc_fifo: a queue for storing service message data
  * @complete_status: state for completion
- * @svc_fifo_lock: protect access to service message data queue
  * @invoke_fn: function to issue secure monitor call or hypervisor call
  * @svc: manages the list of client svc drivers
+ * @sdm_lock: only allows a single command single response to SDM
  * @actrl: async control structure
  *
  * This struct is used to create communication channels for service clients, to
@@ -269,12 +264,10 @@ struct stratix10_svc_controller {
 	int num_active_client;
 	struct list_head node;
 	struct gen_pool *genpool;
-	struct task_struct *task;
-	struct kfifo svc_fifo;
 	struct completion complete_status;
-	spinlock_t svc_fifo_lock;
 	svc_invoke_fn *invoke_fn;
 	struct stratix10_svc *svc;
+	struct mutex sdm_lock;
 	struct stratix10_async_ctrl actrl;
 };
 
@@ -283,6 +276,9 @@ struct stratix10_svc_controller {
  * @ctrl: pointer to service controller which is the provider of this channel
  * @scl: pointer to service client which owns the channel
  * @name: service client name associated with the channel
+ * @task: pointer to the thread task which handles SMC or HVC call
+ * @svc_fifo: a queue for storing service message data (separate fifo for every channel)
+ * @svc_fifo_lock: protect access to service message data queue (locking pending fifo)
  * @lock: protect access to the channel
  * @async_chan: reference to asynchronous channel object for this channel
  *
@@ -293,6 +289,9 @@ struct stratix10_svc_chan {
 	struct stratix10_svc_controller *ctrl;
 	struct stratix10_svc_client *scl;
 	char *name;
+	struct task_struct *task;
+	struct kfifo svc_fifo;
+	spinlock_t svc_fifo_lock;
 	spinlock_t lock;
 	struct stratix10_async_chan *async_chan;
 };
@@ -527,10 +526,10 @@ static void svc_thread_recv_status_ok(st
  */
 static int svc_normal_to_secure_thread(void *data)
 {
-	struct stratix10_svc_controller
-			*ctrl = (struct stratix10_svc_controller *)data;
-	struct stratix10_svc_data *pdata;
-	struct stratix10_svc_cb_data *cbdata;
+	struct stratix10_svc_chan *chan = (struct stratix10_svc_chan *)data;
+	struct stratix10_svc_controller *ctrl = chan->ctrl;
+	struct stratix10_svc_data *pdata = NULL;
+	struct stratix10_svc_cb_data *cbdata = NULL;
 	struct arm_smccc_res res;
 	unsigned long a0, a1, a2, a3, a4, a5, a6, a7;
 	int ret_fifo = 0;
@@ -555,12 +554,12 @@ static int svc_normal_to_secure_thread(v
 	a6 = 0;
 	a7 = 0;
 
-	pr_debug("smc_hvc_shm_thread is running\n");
+	pr_debug("%s: %s: Thread is running!\n", __func__, chan->name);
 
 	while (!kthread_should_stop()) {
-		ret_fifo = kfifo_out_spinlocked(&ctrl->svc_fifo,
+		ret_fifo = kfifo_out_spinlocked(&chan->svc_fifo,
 						pdata, sizeof(*pdata),
-						&ctrl->svc_fifo_lock);
+						&chan->svc_fifo_lock);
 
 		if (!ret_fifo)
 			continue;
@@ -569,9 +568,25 @@ static int svc_normal_to_secure_thread(v
 			 (unsigned int)pdata->paddr, pdata->command,
 			 (unsigned int)pdata->size);
 
+		/* SDM can only process one command at a time */
+		pr_debug("%s: %s: Thread is waiting for mutex!\n",
+			 __func__, chan->name);
+		if (mutex_lock_interruptible(&ctrl->sdm_lock)) {
+			/* item already dequeued; notify client to unblock it */
+			cbdata->status = BIT(SVC_STATUS_ERROR);
+			cbdata->kaddr1 = NULL;
+			cbdata->kaddr2 = NULL;
+			cbdata->kaddr3 = NULL;
+			if (pdata->chan->scl)
+				pdata->chan->scl->receive_cb(pdata->chan->scl,
+							     cbdata);
+			break;
+		}
+
 		switch (pdata->command) {
 		case COMMAND_RECONFIG_DATA_CLAIM:
 			svc_thread_cmd_data_claim(ctrl, pdata, cbdata);
+			mutex_unlock(&ctrl->sdm_lock);
 			continue;
 		case COMMAND_RECONFIG:
 			a0 = INTEL_SIP_SMC_FPGA_CONFIG_START;
@@ -700,10 +715,11 @@ static int svc_normal_to_secure_thread(v
 			break;
 		default:
 			pr_warn("it shouldn't happen\n");
-			break;
+			mutex_unlock(&ctrl->sdm_lock);
+			continue;
 		}
-		pr_debug("%s: before SMC call -- a0=0x%016x a1=0x%016x",
-			 __func__,
+		pr_debug("%s: %s: before SMC call -- a0=0x%016x a1=0x%016x",
+			 __func__, chan->name,
 			 (unsigned int)a0,
 			 (unsigned int)a1);
 		pr_debug(" a2=0x%016x\n", (unsigned int)a2);
@@ -712,8 +728,8 @@ static int svc_normal_to_secure_thread(v
 		pr_debug(" a5=0x%016x\n", (unsigned int)a5);
 		ctrl->invoke_fn(a0, a1, a2, a3, a4, a5, a6, a7, &res);
 
-		pr_debug("%s: after SMC call -- res.a0=0x%016x",
-			 __func__, (unsigned int)res.a0);
+		pr_debug("%s: %s: after SMC call -- res.a0=0x%016x",
+			 __func__, chan->name, (unsigned int)res.a0);
 		pr_debug(" res.a1=0x%016x, res.a2=0x%016x",
 			 (unsigned int)res.a1, (unsigned int)res.a2);
 		pr_debug(" res.a3=0x%016x\n", (unsigned int)res.a3);
@@ -728,6 +744,7 @@ static int svc_normal_to_secure_thread(v
 			cbdata->kaddr2 = NULL;
 			cbdata->kaddr3 = NULL;
 			pdata->chan->scl->receive_cb(pdata->chan->scl, cbdata);
+			mutex_unlock(&ctrl->sdm_lock);
 			continue;
 		}
 
@@ -801,6 +818,8 @@ static int svc_normal_to_secure_thread(v
 			break;
 
 		}
+
+		mutex_unlock(&ctrl->sdm_lock);
 	}
 
 	kfree(cbdata);
@@ -1696,22 +1715,33 @@ int stratix10_svc_send(struct stratix10_
 	if (!p_data)
 		return -ENOMEM;
 
-	/* first client will create kernel thread */
-	if (!chan->ctrl->task) {
-		chan->ctrl->task =
-			kthread_run_on_cpu(svc_normal_to_secure_thread,
-					   (void *)chan->ctrl,
-					   cpu, "svc_smc_hvc_thread");
-		if (IS_ERR(chan->ctrl->task)) {
+	/* first caller creates the per-channel kthread */
+	if (!chan->task) {
+		struct task_struct *task;
+
+		task = kthread_run_on_cpu(svc_normal_to_secure_thread,
+					  (void *)chan,
+					  cpu, "svc_smc_hvc_thread");
+		if (IS_ERR(task)) {
 			dev_err(chan->ctrl->dev,
 				"failed to create svc_smc_hvc_thread\n");
 			kfree(p_data);
 			return -EINVAL;
 		}
+
+		spin_lock(&chan->lock);
+		if (chan->task) {
+			/* another caller won the race; discard our thread */
+			spin_unlock(&chan->lock);
+			kthread_stop(task);
+		} else {
+			chan->task = task;
+			spin_unlock(&chan->lock);
+		}
 	}
 
-	pr_debug("%s: sent P-va=%p, P-com=%x, P-size=%u\n", __func__,
-		 p_msg->payload, p_msg->command,
+	pr_debug("%s: %s: sent P-va=%p, P-com=%x, P-size=%u\n", __func__,
+		 chan->name, p_msg->payload, p_msg->command,
 		 (unsigned int)p_msg->payload_length);
 
 	if (list_empty(&svc_data_mem)) {
@@ -1747,12 +1777,16 @@ int stratix10_svc_send(struct stratix10_
 	p_data->arg[2] = p_msg->arg[2];
 	p_data->size = p_msg->payload_length;
 	p_data->chan = chan;
-	pr_debug("%s: put to FIFO pa=0x%016x, cmd=%x, size=%u\n", __func__,
-	       (unsigned int)p_data->paddr, p_data->command,
-	       (unsigned int)p_data->size);
-	ret = kfifo_in_spinlocked(&chan->ctrl->svc_fifo, p_data,
+	pr_debug("%s: %s: put to FIFO pa=0x%016x, cmd=%x, size=%u\n",
+		 __func__,
+		 chan->name,
+		 (unsigned int)p_data->paddr,
+		 p_data->command,
+		 (unsigned int)p_data->size);
+
+	ret = kfifo_in_spinlocked(&chan->svc_fifo, p_data,
 				  sizeof(*p_data),
-				  &chan->ctrl->svc_fifo_lock);
+				  &chan->svc_fifo_lock);
 
 	kfree(p_data);
 
@@ -1773,11 +1807,12 @@ EXPORT_SYMBOL_GPL(stratix10_svc_send);
  */
 void stratix10_svc_done(struct stratix10_svc_chan *chan)
 {
-	/* stop thread when thread is running AND only one active client */
-	if (chan->ctrl->task && chan->ctrl->num_active_client <= 1) {
-		pr_debug("svc_smc_hvc_shm_thread is stopped\n");
-		kthread_stop(chan->ctrl->task);
-		chan->ctrl->task = NULL;
+	/* stop thread when thread is running */
+	if (chan->task) {
+		pr_debug("%s: %s: svc_smc_hvc_shm_thread is stopping\n",
+			 __func__, chan->name);
+		kthread_stop(chan->task);
+		chan->task = NULL;
 	}
 }
 EXPORT_SYMBOL_GPL(stratix10_svc_done);
@@ -1817,8 +1852,8 @@ void *stratix10_svc_allocate_memory(stru
 	pmem->paddr = pa;
 	pmem->size = s;
 	list_add_tail(&pmem->node, &svc_data_mem);
-	pr_debug("%s: va=%p, pa=0x%016x\n", __func__,
-		 pmem->vaddr, (unsigned int)pmem->paddr);
+	pr_debug("%s: %s: va=%p, pa=0x%016x\n", __func__,
+		 chan->name, pmem->vaddr, (unsigned int)pmem->paddr);
 
 	return (void *)va;
 }
@@ -1855,6 +1890,13 @@ static const struct of_device_id stratix
 	{},
 };
 
+static const char * const chan_names[SVC_NUM_CHANNEL] = {
+	SVC_CLIENT_FPGA,
+	SVC_CLIENT_RSU,
+	SVC_CLIENT_FCS,
+	SVC_CLIENT_HWMON
+};
+
 static int stratix10_svc_drv_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -1862,11 +1904,11 @@ static int stratix10_svc_drv_probe(struc
 	struct stratix10_svc_chan *chans;
 	struct gen_pool *genpool;
 	struct stratix10_svc_sh_memory *sh_memory;
-	struct stratix10_svc *svc;
+	struct stratix10_svc *svc = NULL;
 
 	svc_invoke_fn *invoke_fn;
 	size_t fifo_size;
-	int ret;
+	int ret, i = 0;
 
 	/* get SMC or HVC function */
 	invoke_fn = get_invoke_func(dev);
@@ -1905,8 +1947,8 @@ static int stratix10_svc_drv_probe(struc
 	controller->num_active_client = 0;
 	controller->chans = chans;
 	controller->genpool = genpool;
-	controller->task = NULL;
 	controller->invoke_fn = invoke_fn;
+	INIT_LIST_HEAD(&controller->node);
 	init_completion(&controller->complete_status);
 
 	ret = stratix10_svc_async_init(controller);
@@ -1917,32 +1959,20 @@ static int stratix10_svc_drv_probe(struc
 	}
 
 	fifo_size = sizeof(struct stratix10_svc_data) * SVC_NUM_DATA_IN_FIFO;
-	ret = kfifo_alloc(&controller->svc_fifo, fifo_size, GFP_KERNEL);
-	if (ret) {
-		dev_err(dev, "failed to allocate FIFO\n");
-		goto err_async_exit;
-	}
-	spin_lock_init(&controller->svc_fifo_lock);
+	mutex_init(&controller->sdm_lock);
 
-	chans[0].scl = NULL;
-	chans[0].ctrl = controller;
-	chans[0].name = SVC_CLIENT_FPGA;
-	spin_lock_init(&chans[0].lock);
-
-	chans[1].scl = NULL;
-	chans[1].ctrl = controller;
-	chans[1].name = SVC_CLIENT_RSU;
-	spin_lock_init(&chans[1].lock);
-
-	chans[2].scl = NULL;
-	chans[2].ctrl = controller;
-	chans[2].name = SVC_CLIENT_FCS;
-	spin_lock_init(&chans[2].lock);
-
-	chans[3].scl = NULL;
-	chans[3].ctrl = controller;
-	chans[3].name = SVC_CLIENT_HWMON;
-	spin_lock_init(&chans[3].lock);
+	for (i = 0; i < SVC_NUM_CHANNEL; i++) {
+		chans[i].scl = NULL;
+		chans[i].ctrl = controller;
+		chans[i].name = (char *)chan_names[i];
+		spin_lock_init(&chans[i].lock);
+		ret = kfifo_alloc(&chans[i].svc_fifo, fifo_size, GFP_KERNEL);
+		if (ret) {
+			dev_err(dev, "failed to allocate FIFO %d\n", i);
+			goto err_free_fifos;
+		}
+		spin_lock_init(&chans[i].svc_fifo_lock);
+	}
 
 	list_add_tail(&controller->node, &svc_ctrl);
 	platform_set_drvdata(pdev, controller);
@@ -1951,7 +1981,7 @@ static int stratix10_svc_drv_probe(struc
 	svc = devm_kzalloc(dev, sizeof(*svc), GFP_KERNEL);
 	if (!svc) {
 		ret = -ENOMEM;
-		goto err_free_kfifo;
+		goto err_free_fifos;
 	}
 	controller->svc = svc;
 
@@ -1959,51 +1989,43 @@ static int stratix10_svc_drv_probe(struc
 	if (!svc->stratix10_svc_rsu) {
 		dev_err(dev, "failed to allocate %s device\n", STRATIX10_RSU);
 		ret = -ENOMEM;
-		goto err_free_kfifo;
+		goto err_free_fifos;
 	}
 
 	ret = platform_device_add(svc->stratix10_svc_rsu);
-	if (ret) {
-		platform_device_put(svc->stratix10_svc_rsu);
-		goto err_free_kfifo;
-	}
-
-	svc->intel_svc_fcs = platform_device_alloc(INTEL_FCS, 1);
-	if (!svc->intel_svc_fcs) {
-		dev_err(dev, "failed to allocate %s device\n", INTEL_FCS);
-		ret = -ENOMEM;
-		goto err_unregister_rsu_dev;
-	}
-
-	ret = platform_device_add(svc->intel_svc_fcs);
-	if (ret) {
-		platform_device_put(svc->intel_svc_fcs);
-		goto err_unregister_rsu_dev;
-	}
+	if (ret)
+		goto err_put_device;
 
 	ret = of_platform_default_populate(dev_of_node(dev), NULL, dev);
 	if (ret)
-		goto err_unregister_fcs_dev;
+		goto err_unregister_rsu_dev;
 
 	pr_info("Intel Service Layer Driver Initialized\n");
 
 	return 0;
 
-err_unregister_fcs_dev:
-	platform_device_unregister(svc->intel_svc_fcs);
 err_unregister_rsu_dev:
 	platform_device_unregister(svc->stratix10_svc_rsu);
-err_free_kfifo:
-	kfifo_free(&controller->svc_fifo);
-err_async_exit:
+	goto err_free_fifos;
+err_put_device:
+	platform_device_put(svc->stratix10_svc_rsu);
+err_free_fifos:
+	/* only remove from list if list_add_tail() was reached */
+	if (!list_empty(&controller->node))
+		list_del(&controller->node);
+	/* free only the FIFOs that were successfully allocated */
+	while (i--)
+		kfifo_free(&chans[i].svc_fifo);
 	stratix10_svc_async_exit(controller);
 err_destroy_pool:
 	gen_pool_destroy(genpool);
+
 	return ret;
 }
 
 static void stratix10_svc_drv_remove(struct platform_device *pdev)
 {
+	int i;
 	struct stratix10_svc_controller *ctrl = platform_get_drvdata(pdev);
 	struct stratix10_svc *svc = ctrl->svc;
 
@@ -2011,14 +2033,16 @@ static void stratix10_svc_drv_remove(str
 
 	of_platform_depopulate(ctrl->dev);
 
-	platform_device_unregister(svc->intel_svc_fcs);
 	platform_device_unregister(svc->stratix10_svc_rsu);
 
-	kfifo_free(&ctrl->svc_fifo);
-	if (ctrl->task) {
-		kthread_stop(ctrl->task);
-		ctrl->task = NULL;
+	for (i = 0; i < SVC_NUM_CHANNEL; i++) {
+		if (ctrl->chans[i].task) {
+			kthread_stop(ctrl->chans[i].task);
+			ctrl->chans[i].task = NULL;
+		}
+		kfifo_free(&ctrl->chans[i].svc_fifo);
 	}
+
 	if (ctrl->genpool)
 		gen_pool_destroy(ctrl->genpool);
 	list_del(&ctrl->node);
--- a/include/linux/firmware/intel/stratix10-svc-client.h
+++ b/include/linux/firmware/intel/stratix10-svc-client.h
@@ -68,12 +68,12 @@
  * timeout value used in Stratix10 FPGA manager driver.
  * timeout value used in RSU driver
  */
-#define SVC_RECONFIG_REQUEST_TIMEOUT_MS         300
-#define SVC_RECONFIG_BUFFER_TIMEOUT_MS          720
-#define SVC_RSU_REQUEST_TIMEOUT_MS              300
+#define SVC_RECONFIG_REQUEST_TIMEOUT_MS         5000
+#define SVC_RECONFIG_BUFFER_TIMEOUT_MS          5000
+#define SVC_RSU_REQUEST_TIMEOUT_MS              2000
 #define SVC_FCS_REQUEST_TIMEOUT_MS		2000
 #define SVC_COMPLETED_TIMEOUT_MS		30000
-#define SVC_HWMON_REQUEST_TIMEOUT_MS		300
+#define SVC_HWMON_REQUEST_TIMEOUT_MS		2000
 
 struct stratix10_svc_chan;