[v4] firmware: stratix10-svc: Add Multi SVC clients support

Muhammad Amirul Asyraf Mohamad Jamian posted 1 patch 1 month, 3 weeks ago
There is a newer version of this series
drivers/firmware/stratix10-svc.c              | 202 +++++++++++-------
.../firmware/intel/stratix10-svc-client.h     |   8 +-
2 files changed, 131 insertions(+), 79 deletions(-)
[v4] firmware: stratix10-svc: Add Multi SVC clients support
Posted by Muhammad Amirul Asyraf Mohamad Jamian 1 month, 3 weeks ago
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.

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@intel.com>
Signed-off-by: Fong, Yan Kei <yankei.fong@altera.com>
Signed-off-by: Muhammad Amirul Asyraf Mohamad Jamian <muhammadamirulasyraf.mohamadjamian@altera.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202602032325.MuglZ156-lkp@intel.com/
---
Changes in v4:
- Signed-off-by chain clean up
- Remove duplicate inline comment on sdm_lock field
- Move structure field comments to structure header
- Remove unnecessary checks in stratix10_svc_done()
- Fix error handling to properly free FIFOs on probe failure
- Reorder error labels for proper cleanup cascade
- Remove redundant fifo_size initialization

Changes in v3:
- Fix grammar: "will supports" -> "will support"
- Add Fixes tag and Cc stable as suggested by reviewer

Changes in v2:
- Initialize 'svc' to NULL and add NULL check in error path to fix uninitialized variable warning
---
---
 drivers/firmware/stratix10-svc.c              | 202 +++++++++++-------
 .../firmware/intel/stratix10-svc-client.h     |   8 +-
 2 files changed, 131 insertions(+), 79 deletions(-)

diff --git a/drivers/firmware/stratix10-svc.c b/drivers/firmware/stratix10-svc.c
index 515b948ff320..77fa8da6ea92 100644
--- a/drivers/firmware/stratix10-svc.c
+++ b/drivers/firmware/stratix10-svc.c
@@ -37,9 +37,9 @@
  * 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
 
@@ -252,11 +252,10 @@ struct stratix10_async_ctrl {
  * @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 +268,10 @@ 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 +280,9 @@ 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 +293,9 @@ 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;
 };
@@ -527,13 +530,14 @@ static void svc_thread_recv_status_ok(struct stratix10_svc_data *p_data,
  */
 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;
+	bool sdm_lock_owned = false;
 
 	pdata =  kmalloc(sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
@@ -555,12 +559,12 @@ static int svc_normal_to_secure_thread(void *data)
 	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;
@@ -569,6 +573,16 @@ static int svc_normal_to_secure_thread(void *data)
 			 (unsigned int)pdata->paddr, pdata->command,
 			 (unsigned int)pdata->size);
 
+		/* SDM can only processs one command at a time */
+		if (!sdm_lock_owned) {
+			/* Must not do mutex re-lock */
+			pr_debug("%s: %s: Thread is waiting for mutex!\n",
+				 __func__, chan->name);
+			guard(mutex)(ctrl->sdm_lock);
+		}
+
+		sdm_lock_owned = true;
+
 		switch (pdata->command) {
 		case COMMAND_RECONFIG_DATA_CLAIM:
 			svc_thread_cmd_data_claim(ctrl, pdata, cbdata);
@@ -702,8 +716,8 @@ static int svc_normal_to_secure_thread(void *data)
 			pr_warn("it shouldn't happen\n");
 			break;
 		}
-		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 +726,8 @@ static int svc_normal_to_secure_thread(void *data)
 		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 +742,7 @@ static int svc_normal_to_secure_thread(void *data)
 			cbdata->kaddr2 = NULL;
 			cbdata->kaddr3 = NULL;
 			pdata->chan->scl->receive_cb(pdata->chan->scl, cbdata);
+			sdm_lock_owned = false;
 			continue;
 		}
 
@@ -1697,21 +1712,21 @@ int stratix10_svc_send(struct stratix10_svc_chan *chan, void *msg)
 		return -ENOMEM;
 
 	/* first client will create kernel thread */
-	if (!chan->ctrl->task) {
-		chan->ctrl->task =
+	if (!chan->task) {
+		chan->task =
 			kthread_run_on_cpu(svc_normal_to_secure_thread,
-					   (void *)chan->ctrl,
+					   (void *)chan,
 					   cpu, "svc_smc_hvc_thread");
-			if (IS_ERR(chan->ctrl->task)) {
-				dev_err(chan->ctrl->dev,
-					"failed to create svc_smc_hvc_thread\n");
-				kfree(p_data);
-				return -EINVAL;
-			}
+		if (IS_ERR(chan->task)) {
+			dev_err(chan->ctrl->dev,
+				"failed to create svc_smc_hvc_thread\n");
+			kfree(p_data);
+			return -EINVAL;
+		}
 	}
 
-	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 +1762,16 @@ int stratix10_svc_send(struct stratix10_svc_chan *chan, void *msg)
 	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);
 
@@ -1773,12 +1792,15 @@ 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;
 	}
+	pr_debug("%s: %s: svc_smc_hvc_shm_thread has stopped\n",
+		 __func__, chan->name);
 }
 EXPORT_SYMBOL_GPL(stratix10_svc_done);
 
@@ -1817,8 +1839,8 @@ void *stratix10_svc_allocate_memory(struct stratix10_svc_chan *chan,
 	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 +1877,11 @@ static const struct of_device_id stratix10_svc_drv_match[] = {
 	{},
 };
 
+/**
+ * mailbox_lock protects access to the to SDM if thread is busy
+ */
+static DEFINE_MUTEX(mailbox_lock);
+
 static int stratix10_svc_drv_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -1862,7 +1889,7 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
 	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;
@@ -1905,7 +1932,6 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
 	controller->num_active_client = 0;
 	controller->chans = chans;
 	controller->genpool = genpool;
-	controller->task = NULL;
 	controller->invoke_fn = invoke_fn;
 	init_completion(&controller->complete_status);
 
@@ -1917,32 +1943,61 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
 	}
 
 	fifo_size = sizeof(struct stratix10_svc_data) * SVC_NUM_DATA_IN_FIFO;
-	ret = kfifo_alloc(&controller->svc_fifo, fifo_size, GFP_KERNEL);
+	ret = kfifo_alloc(&chans->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);
+	spin_lock_init(&chans->svc_fifo_lock);
+	/*
+	 * This mutex is used to block threads from utilizing
+	 * SDM to prevent out of order command tx
+	 */
+	controller->sdm_lock = &mailbox_lock;
 
 	chans[0].scl = NULL;
 	chans[0].ctrl = controller;
 	chans[0].name = SVC_CLIENT_FPGA;
 	spin_lock_init(&chans[0].lock);
+	ret = kfifo_alloc(&chans[0].svc_fifo, fifo_size, GFP_KERNEL);
+	if (ret) {
+		dev_err(dev, "failed to allocate FIFO 0\n");
+		goto err_free_chans_fifo;
+	}
+	spin_lock_init(&chans[0].svc_fifo_lock);
 
 	chans[1].scl = NULL;
 	chans[1].ctrl = controller;
 	chans[1].name = SVC_CLIENT_RSU;
 	spin_lock_init(&chans[1].lock);
+	ret = kfifo_alloc(&chans[1].svc_fifo, fifo_size, GFP_KERNEL);
+	if (ret) {
+		dev_err(dev, "failed to allocate FIFO 1\n");
+		goto err_free_fifo_fpga;
+	}
+	spin_lock_init(&chans[1].svc_fifo_lock);
 
 	chans[2].scl = NULL;
 	chans[2].ctrl = controller;
 	chans[2].name = SVC_CLIENT_FCS;
 	spin_lock_init(&chans[2].lock);
+	ret = kfifo_alloc(&chans[2].svc_fifo, fifo_size, GFP_KERNEL);
+	if (ret) {
+		dev_err(dev, "failed to allocate FIFO 2\n");
+		goto err_free_fifo_rsu;
+	}
+	spin_lock_init(&chans[2].svc_fifo_lock);
 
 	chans[3].scl = NULL;
 	chans[3].ctrl = controller;
 	chans[3].name = SVC_CLIENT_HWMON;
 	spin_lock_init(&chans[3].lock);
+	ret = kfifo_alloc(&chans[3].svc_fifo, fifo_size, GFP_KERNEL);
+	if (ret) {
+		dev_err(dev, "failed to allocate FIFO 3\n");
+		goto err_free_fifo_fcs;
+	}
+	spin_lock_init(&chans[3].svc_fifo_lock);
 
 	list_add_tail(&controller->node, &svc_ctrl);
 	platform_set_drvdata(pdev, controller);
@@ -1951,7 +2006,7 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
 	svc = devm_kzalloc(dev, sizeof(*svc), GFP_KERNEL);
 	if (!svc) {
 		ret = -ENOMEM;
-		goto err_free_kfifo;
+		goto err_free_fifo_hwmon;
 	}
 	controller->svc = svc;
 
@@ -1959,51 +2014,45 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
 	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_fifo_hwmon;
 	}
 
 	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_put_device;
 
 	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_put_device:
+	if (svc)
+		platform_device_put(svc->stratix10_svc_rsu);
+err_free_fifo_hwmon:
+	kfifo_free(&chans[3].svc_fifo);
+err_free_fifo_fcs:
+	kfifo_free(&chans[2].svc_fifo);
+err_free_fifo_rsu:
+	kfifo_free(&chans[1].svc_fifo);
+err_free_fifo_fpga:
+	kfifo_free(&chans[0].svc_fifo);
+err_free_chans_fifo:
+	kfifo_free(&chans->svc_fifo);
 err_async_exit:
 	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;
 
@@ -2014,11 +2063,14 @@ static void stratix10_svc_drv_remove(struct platform_device *pdev)
 	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);
diff --git a/include/linux/firmware/intel/stratix10-svc-client.h b/include/linux/firmware/intel/stratix10-svc-client.h
index d290060f4c73..91013161e9db 100644
--- 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;
 
-- 
2.43.7
Re: [v4] firmware: stratix10-svc: Add Multi SVC clients support
Posted by Dinh Nguyen 1 month, 3 weeks ago

On 2/23/26 01:05, Muhammad Amirul Asyraf Mohamad Jamian wrote:
> 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.
> 
> 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@intel.com>
> Signed-off-by: Fong, Yan Kei <yankei.fong@altera.com>
> Signed-off-by: Muhammad Amirul Asyraf Mohamad Jamian <muhammadamirulasyraf.mohamadjamian@altera.com>
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202602032325.MuglZ156-lkp@intel.com/
> ---
> Changes in v4:
> - Signed-off-by chain clean up
> - Remove duplicate inline comment on sdm_lock field
> - Move structure field comments to structure header
> - Remove unnecessary checks in stratix10_svc_done()
> - Fix error handling to properly free FIFOs on probe failure
> - Reorder error labels for proper cleanup cascade
> - Remove redundant fifo_size initialization
> 

Your commit header should be "[PATCH v4]". Also please rebase this patch 
to v7.0-rc1. This patch no longer applies cleanly.

> Changes in v3:
> - Fix grammar: "will supports" -> "will support"
> - Add Fixes tag and Cc stable as suggested by reviewer
> 
> Changes in v2:
> - Initialize 'svc' to NULL and add NULL check in error path to fix uninitialized variable warning
> ---
> ---
>   drivers/firmware/stratix10-svc.c              | 202 +++++++++++-------
>   .../firmware/intel/stratix10-svc-client.h     |   8 +-
>   2 files changed, 131 insertions(+), 79 deletions(-)
> 
> diff --git a/drivers/firmware/stratix10-svc.c b/drivers/firmware/stratix10-svc.c
> index 515b948ff320..77fa8da6ea92 100644
> --- a/drivers/firmware/stratix10-svc.c
> +++ b/drivers/firmware/stratix10-svc.c
> @@ -37,9 +37,9 @@
>    * 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
>   
> @@ -252,11 +252,10 @@ struct stratix10_async_ctrl {
>    * @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 +268,10 @@ 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 +280,9 @@ 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 +293,9 @@ 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;
>   };
> @@ -527,13 +530,14 @@ static void svc_thread_recv_status_ok(struct stratix10_svc_data *p_data,
>    */
>   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;
> +	bool sdm_lock_owned = false;
>   
>   	pdata =  kmalloc(sizeof(*pdata), GFP_KERNEL);
>   	if (!pdata)
> @@ -555,12 +559,12 @@ static int svc_normal_to_secure_thread(void *data)
>   	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;
> @@ -569,6 +573,16 @@ static int svc_normal_to_secure_thread(void *data)
>   			 (unsigned int)pdata->paddr, pdata->command,
>   			 (unsigned int)pdata->size);
>   
> +		/* SDM can only processs one command at a time */
> +		if (!sdm_lock_owned) {
> +			/* Must not do mutex re-lock */
> +			pr_debug("%s: %s: Thread is waiting for mutex!\n",
> +				 __func__, chan->name);
> +			guard(mutex)(ctrl->sdm_lock);
> +		}
> +
> +		sdm_lock_owned = true;
> +
>   		switch (pdata->command) {
>   		case COMMAND_RECONFIG_DATA_CLAIM:
>   			svc_thread_cmd_data_claim(ctrl, pdata, cbdata);
> @@ -702,8 +716,8 @@ static int svc_normal_to_secure_thread(void *data)
>   			pr_warn("it shouldn't happen\n");
>   			break;
>   		}
> -		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 +726,8 @@ static int svc_normal_to_secure_thread(void *data)
>   		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 +742,7 @@ static int svc_normal_to_secure_thread(void *data)
>   			cbdata->kaddr2 = NULL;
>   			cbdata->kaddr3 = NULL;
>   			pdata->chan->scl->receive_cb(pdata->chan->scl, cbdata);
> +			sdm_lock_owned = false;
>   			continue;
>   		}
>   
> @@ -1697,21 +1712,21 @@ int stratix10_svc_send(struct stratix10_svc_chan *chan, void *msg)
>   		return -ENOMEM;
>   
>   	/* first client will create kernel thread */
> -	if (!chan->ctrl->task) {
> -		chan->ctrl->task =
> +	if (!chan->task) {
> +		chan->task =
>   			kthread_run_on_cpu(svc_normal_to_secure_thread,
> -					   (void *)chan->ctrl,
> +					   (void *)chan,
>   					   cpu, "svc_smc_hvc_thread");
> -			if (IS_ERR(chan->ctrl->task)) {
> -				dev_err(chan->ctrl->dev,
> -					"failed to create svc_smc_hvc_thread\n");
> -				kfree(p_data);
> -				return -EINVAL;
> -			}
> +		if (IS_ERR(chan->task)) {
> +			dev_err(chan->ctrl->dev,
> +				"failed to create svc_smc_hvc_thread\n");
> +			kfree(p_data);
> +			return -EINVAL;
> +		}
>   	}
>   
> -	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 +1762,16 @@ int stratix10_svc_send(struct stratix10_svc_chan *chan, void *msg)
>   	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);
>   
> @@ -1773,12 +1792,15 @@ 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;
>   	}
> +	pr_debug("%s: %s: svc_smc_hvc_shm_thread has stopped\n",
> +		 __func__, chan->name);
>   }
>   EXPORT_SYMBOL_GPL(stratix10_svc_done);
>   
> @@ -1817,8 +1839,8 @@ void *stratix10_svc_allocate_memory(struct stratix10_svc_chan *chan,
>   	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 +1877,11 @@ static const struct of_device_id stratix10_svc_drv_match[] = {
>   	{},
>   };
>   
> +/**
> + * mailbox_lock protects access to the to SDM if thread is busy
> + */
> +static DEFINE_MUTEX(mailbox_lock);
> +
>   static int stratix10_svc_drv_probe(struct platform_device *pdev)
>   {
>   	struct device *dev = &pdev->dev;
> @@ -1862,7 +1889,7 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
>   	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;
> @@ -1905,7 +1932,6 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
>   	controller->num_active_client = 0;
>   	controller->chans = chans;
>   	controller->genpool = genpool;
> -	controller->task = NULL;
>   	controller->invoke_fn = invoke_fn;
>   	init_completion(&controller->complete_status);
>   
> @@ -1917,32 +1943,61 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
>   	}
>   
>   	fifo_size = sizeof(struct stratix10_svc_data) * SVC_NUM_DATA_IN_FIFO;
> -	ret = kfifo_alloc(&controller->svc_fifo, fifo_size, GFP_KERNEL);
> +	ret = kfifo_alloc(&chans->svc_fifo, fifo_size, GFP_KERNEL);

You are allocating a svc_fifo for chan 0 here,

>   	if (ret) {
>   		dev_err(dev, "failed to allocate FIFO\n");
>   		goto err_async_exit;
>   	}
> -	spin_lock_init(&controller->svc_fifo_lock);
> +	spin_lock_init(&chans->svc_fifo_lock);
> +	/*
> +	 * This mutex is used to block threads from utilizing
> +	 * SDM to prevent out of order command tx
> +	 */
> +	controller->sdm_lock = &mailbox_lock;
>   
>   	chans[0].scl = NULL;
>   	chans[0].ctrl = controller;
>   	chans[0].name = SVC_CLIENT_FPGA;
>   	spin_lock_init(&chans[0].lock);
> +	ret = kfifo_alloc(&chans[0].svc_fifo, fifo_size, GFP_KERNEL);

then you're re-allocating another svc_fifo chan[0] here?

> +	if (ret) {
> +		dev_err(dev, "failed to allocate FIFO 0\n");
> +		goto err_free_chans_fifo;
> +	}
> +	spin_lock_init(&chans[0].svc_fifo_lock);
>   
>   	chans[1].scl = NULL;
>   	chans[1].ctrl = controller;
>   	chans[1].name = SVC_CLIENT_RSU;
>   	spin_lock_init(&chans[1].lock);
> +	ret = kfifo_alloc(&chans[1].svc_fifo, fifo_size, GFP_KERNEL);
> +	if (ret) {
> +		dev_err(dev, "failed to allocate FIFO 1\n");
> +		goto err_free_fifo_fpga;
> +	}
> +	spin_lock_init(&chans[1].svc_fifo_lock);
>   
>   	chans[2].scl = NULL;
>   	chans[2].ctrl = controller;
>   	chans[2].name = SVC_CLIENT_FCS;
>   	spin_lock_init(&chans[2].lock);
> +	ret = kfifo_alloc(&chans[2].svc_fifo, fifo_size, GFP_KERNEL);
> +	if (ret) {
> +		dev_err(dev, "failed to allocate FIFO 2\n");
> +		goto err_free_fifo_rsu;
> +	}
> +	spin_lock_init(&chans[2].svc_fifo_lock);
>   
>   	chans[3].scl = NULL;
>   	chans[3].ctrl = controller;
>   	chans[3].name = SVC_CLIENT_HWMON;
>   	spin_lock_init(&chans[3].lock);
> +	ret = kfifo_alloc(&chans[3].svc_fifo, fifo_size, GFP_KERNEL);
> +	if (ret) {
> +		dev_err(dev, "failed to allocate FIFO 3\n");
> +		goto err_free_fifo_fcs;
> +	}
> +	spin_lock_init(&chans[3].svc_fifo_lock);

I think allocating the channel svc_fifo's would be cleaner and more 
maintainable if you use a for loop.

>   
>   	list_add_tail(&controller->node, &svc_ctrl);
>   	platform_set_drvdata(pdev, controller);
> @@ -1951,7 +2006,7 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
>   	svc = devm_kzalloc(dev, sizeof(*svc), GFP_KERNEL);
>   	if (!svc) {
>   		ret = -ENOMEM;
> -		goto err_free_kfifo;
> +		goto err_free_fifo_hwmon;
>   	}
>   	controller->svc = svc;
>   
> @@ -1959,51 +2014,45 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
>   	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_fifo_hwmon;
>   	}
>   
>   	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_put_device;
>   
>   	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_put_device:
> +	if (svc)
> +		platform_device_put(svc->stratix10_svc_rsu);

Why the need to check if svc is valid here?

Dinh
Re: [v4] firmware: stratix10-svc: Add Multi SVC clients support
Posted by MOHAMAD JAMIAN, MUHAMMAD AMIRUL ASYRAF 1 month, 2 weeks ago
On 24/2/2026 12:00 pm, Dinh Nguyen wrote:
> 
> 
> On 2/23/26 01:05, Muhammad Amirul Asyraf Mohamad Jamian wrote:
>> 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.
>>
>> 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@intel.com>
>> Signed-off-by: Fong, Yan Kei <yankei.fong@altera.com>
>> Signed-off-by: Muhammad Amirul Asyraf Mohamad Jamian 
>> <muhammadamirulasyraf.mohamadjamian@altera.com>
>> Reported-by: kernel test robot <lkp@intel.com>
>> Closes: https://nam10.safelinks.protection.outlook.com/? 
>> url=https%3A%2F%2Flore.kernel.org%2Foe-kbuild- 
>> all%2F202602032325.MuglZ156- 
>> lkp%40intel.com%2F&data=05%7C02%7Cmuhammad.amirul.asyraf.mohamad.jamian%40altera.com%7Cabc1f55040fc4bde5bad08de735953d8%7Cfbd72e03d4a54110adce614d51f2077a%7C0%7C0%7C639075024696029819%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=Wb5lw8VPK%2B1pj%2FtVzSFaiy2EB5GZx3bmaRsm8ttWBQE%3D&reserved=0
>> ---
>> Changes in v4:
>> - Signed-off-by chain clean up
>> - Remove duplicate inline comment on sdm_lock field
>> - Move structure field comments to structure header
>> - Remove unnecessary checks in stratix10_svc_done()
>> - Fix error handling to properly free FIFOs on probe failure
>> - Reorder error labels for proper cleanup cascade
>> - Remove redundant fifo_size initialization
>>
> 
> Your commit header should be "[PATCH v4]". Also please rebase this patch 
> to v7.0-rc1. This patch no longer applies cleanly.
> 
>> Changes in v3:
>> - Fix grammar: "will supports" -> "will support"
>> - Add Fixes tag and Cc stable as suggested by reviewer
>>
>> Changes in v2:
>> - Initialize 'svc' to NULL and add NULL check in error path to fix 
>> uninitialized variable warning
>> ---
>> ---
>>   drivers/firmware/stratix10-svc.c              | 202 +++++++++++-------
>>   .../firmware/intel/stratix10-svc-client.h     |   8 +-
>>   2 files changed, 131 insertions(+), 79 deletions(-)
>>
>> diff --git a/drivers/firmware/stratix10-svc.c b/drivers/firmware/ 
>> stratix10-svc.c
>> index 515b948ff320..77fa8da6ea92 100644
>> --- a/drivers/firmware/stratix10-svc.c
>> +++ b/drivers/firmware/stratix10-svc.c
>> @@ -37,9 +37,9 @@
>>    * 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
>> @@ -252,11 +252,10 @@ struct stratix10_async_ctrl {
>>    * @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 +268,10 @@ 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 +280,9 @@ 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 +293,9 @@ 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;
>>   };
>> @@ -527,13 +530,14 @@ static void svc_thread_recv_status_ok(struct 
>> stratix10_svc_data *p_data,
>>    */
>>   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;
>> +    bool sdm_lock_owned = false;
>>       pdata =  kmalloc(sizeof(*pdata), GFP_KERNEL);
>>       if (!pdata)
>> @@ -555,12 +559,12 @@ static int svc_normal_to_secure_thread(void *data)
>>       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;
>> @@ -569,6 +573,16 @@ static int svc_normal_to_secure_thread(void *data)
>>                (unsigned int)pdata->paddr, pdata->command,
>>                (unsigned int)pdata->size);
>> +        /* SDM can only processs one command at a time */
>> +        if (!sdm_lock_owned) {
>> +            /* Must not do mutex re-lock */
>> +            pr_debug("%s: %s: Thread is waiting for mutex!\n",
>> +                 __func__, chan->name);
>> +            guard(mutex)(ctrl->sdm_lock);
>> +        }
>> +
>> +        sdm_lock_owned = true;
>> +
>>           switch (pdata->command) {
>>           case COMMAND_RECONFIG_DATA_CLAIM:
>>               svc_thread_cmd_data_claim(ctrl, pdata, cbdata);
>> @@ -702,8 +716,8 @@ static int svc_normal_to_secure_thread(void *data)
>>               pr_warn("it shouldn't happen\n");
>>               break;
>>           }
>> -        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 +726,8 @@ static int svc_normal_to_secure_thread(void *data)
>>           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 +742,7 @@ static int svc_normal_to_secure_thread(void *data)
>>               cbdata->kaddr2 = NULL;
>>               cbdata->kaddr3 = NULL;
>>               pdata->chan->scl->receive_cb(pdata->chan->scl, cbdata);
>> +            sdm_lock_owned = false;
>>               continue;
>>           }
>> @@ -1697,21 +1712,21 @@ int stratix10_svc_send(struct 
>> stratix10_svc_chan *chan, void *msg)
>>           return -ENOMEM;
>>       /* first client will create kernel thread */
>> -    if (!chan->ctrl->task) {
>> -        chan->ctrl->task =
>> +    if (!chan->task) {
>> +        chan->task =
>>               kthread_run_on_cpu(svc_normal_to_secure_thread,
>> -                       (void *)chan->ctrl,
>> +                       (void *)chan,
>>                          cpu, "svc_smc_hvc_thread");
>> -            if (IS_ERR(chan->ctrl->task)) {
>> -                dev_err(chan->ctrl->dev,
>> -                    "failed to create svc_smc_hvc_thread\n");
>> -                kfree(p_data);
>> -                return -EINVAL;
>> -            }
>> +        if (IS_ERR(chan->task)) {
>> +            dev_err(chan->ctrl->dev,
>> +                "failed to create svc_smc_hvc_thread\n");
>> +            kfree(p_data);
>> +            return -EINVAL;
>> +        }
>>       }
>> -    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 +1762,16 @@ int stratix10_svc_send(struct 
>> stratix10_svc_chan *chan, void *msg)
>>       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);
>> @@ -1773,12 +1792,15 @@ 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;
>>       }
>> +    pr_debug("%s: %s: svc_smc_hvc_shm_thread has stopped\n",
>> +         __func__, chan->name);
>>   }
>>   EXPORT_SYMBOL_GPL(stratix10_svc_done);
>> @@ -1817,8 +1839,8 @@ void *stratix10_svc_allocate_memory(struct 
>> stratix10_svc_chan *chan,
>>       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 +1877,11 @@ static const struct of_device_id 
>> stratix10_svc_drv_match[] = {
>>       {},
>>   };
>> +/**
>> + * mailbox_lock protects access to the to SDM if thread is busy
>> + */
>> +static DEFINE_MUTEX(mailbox_lock);
>> +
>>   static int stratix10_svc_drv_probe(struct platform_device *pdev)
>>   {
>>       struct device *dev = &pdev->dev;
>> @@ -1862,7 +1889,7 @@ static int stratix10_svc_drv_probe(struct 
>> platform_device *pdev)
>>       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;
>> @@ -1905,7 +1932,6 @@ static int stratix10_svc_drv_probe(struct 
>> platform_device *pdev)
>>       controller->num_active_client = 0;
>>       controller->chans = chans;
>>       controller->genpool = genpool;
>> -    controller->task = NULL;
>>       controller->invoke_fn = invoke_fn;
>>       init_completion(&controller->complete_status);
>> @@ -1917,32 +1943,61 @@ static int stratix10_svc_drv_probe(struct 
>> platform_device *pdev)
>>       }
>>       fifo_size = sizeof(struct stratix10_svc_data) * 
>> SVC_NUM_DATA_IN_FIFO;
>> -    ret = kfifo_alloc(&controller->svc_fifo, fifo_size, GFP_KERNEL);
>> +    ret = kfifo_alloc(&chans->svc_fifo, fifo_size, GFP_KERNEL);
> 
> You are allocating a svc_fifo for chan 0 here,
> 
>>       if (ret) {
>>           dev_err(dev, "failed to allocate FIFO\n");
>>           goto err_async_exit;
>>       }
>> -    spin_lock_init(&controller->svc_fifo_lock);
>> +    spin_lock_init(&chans->svc_fifo_lock);
>> +    /*
>> +     * This mutex is used to block threads from utilizing
>> +     * SDM to prevent out of order command tx
>> +     */
>> +    controller->sdm_lock = &mailbox_lock;
>>       chans[0].scl = NULL;
>>       chans[0].ctrl = controller;
>>       chans[0].name = SVC_CLIENT_FPGA;
>>       spin_lock_init(&chans[0].lock);
>> +    ret = kfifo_alloc(&chans[0].svc_fifo, fifo_size, GFP_KERNEL);
> 
> then you're re-allocating another svc_fifo chan[0] here?
> 
>> +    if (ret) {
>> +        dev_err(dev, "failed to allocate FIFO 0\n");
>> +        goto err_free_chans_fifo;
>> +    }
>> +    spin_lock_init(&chans[0].svc_fifo_lock);
>>       chans[1].scl = NULL;
>>       chans[1].ctrl = controller;
>>       chans[1].name = SVC_CLIENT_RSU;
>>       spin_lock_init(&chans[1].lock);
>> +    ret = kfifo_alloc(&chans[1].svc_fifo, fifo_size, GFP_KERNEL);
>> +    if (ret) {
>> +        dev_err(dev, "failed to allocate FIFO 1\n");
>> +        goto err_free_fifo_fpga;
>> +    }
>> +    spin_lock_init(&chans[1].svc_fifo_lock);
>>       chans[2].scl = NULL;
>>       chans[2].ctrl = controller;
>>       chans[2].name = SVC_CLIENT_FCS;
>>       spin_lock_init(&chans[2].lock);
>> +    ret = kfifo_alloc(&chans[2].svc_fifo, fifo_size, GFP_KERNEL);
>> +    if (ret) {
>> +        dev_err(dev, "failed to allocate FIFO 2\n");
>> +        goto err_free_fifo_rsu;
>> +    }
>> +    spin_lock_init(&chans[2].svc_fifo_lock);
>>       chans[3].scl = NULL;
>>       chans[3].ctrl = controller;
>>       chans[3].name = SVC_CLIENT_HWMON;
>>       spin_lock_init(&chans[3].lock);
>> +    ret = kfifo_alloc(&chans[3].svc_fifo, fifo_size, GFP_KERNEL);
>> +    if (ret) {
>> +        dev_err(dev, "failed to allocate FIFO 3\n");
>> +        goto err_free_fifo_fcs;
>> +    }
>> +    spin_lock_init(&chans[3].svc_fifo_lock);
> 
> I think allocating the channel svc_fifo's would be cleaner and more 
> maintainable if you use a for loop.
> 
>>       list_add_tail(&controller->node, &svc_ctrl);
>>       platform_set_drvdata(pdev, controller);
>> @@ -1951,7 +2006,7 @@ static int stratix10_svc_drv_probe(struct 
>> platform_device *pdev)
>>       svc = devm_kzalloc(dev, sizeof(*svc), GFP_KERNEL);
>>       if (!svc) {
>>           ret = -ENOMEM;
>> -        goto err_free_kfifo;
>> +        goto err_free_fifo_hwmon;
>>       }
>>       controller->svc = svc;
>> @@ -1959,51 +2014,45 @@ static int stratix10_svc_drv_probe(struct 
>> platform_device *pdev)
>>       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_fifo_hwmon;
>>       }
>>       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_put_device;
>>       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_put_device:
>> +    if (svc)
>> +        platform_device_put(svc->stratix10_svc_rsu);
> 
> Why the need to check if svc is valid here?
> 
> Dinh
All comments ddressed in patch v5 
https://lore.kernel.org/all/20260302053944.14300-1-muhammad.amirul.asyraf.mohamad.jamian@altera.com/

Regards,
Amirul