Message-ID: <f2411365-9443-43cf-8420-3afd2c5bf6e2@kernel.og>
Date: Mon, 1 Sep 2025 10:16:48 -0500
From: Dinh Nguyen <dinguyen@...nel.og>
To: mahesh.rao@...era.com, Rob Herring <robh@...nel.org>,
 Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley
 <conor+dt@...nel.org>, Dinh Nguyen <dinguyen@...nel.org>
Cc: devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
 Matthew Gerlach <matthew.gerlach@...era.com>
Subject: Re: [PATCH RESEND v2 4/4] firmware: stratix10-svc: Add for SDM
 mailbox doorbell interrupt



On 8/12/25 07:59, Mahesh Rao via B4 Relay wrote:
> From: Mahesh Rao <mahesh.rao@...era.com>
> 
> Add support for SDM (Secure Device Manager) mailbox
> doorbell interrupt for async transactions. On interrupt,
> a workqueue is triggered which polls the ATF for
> pending responses and retrieves the bitmap of all
> retrieved and unprocessed transaction ids of mailbox
> responses from SDM. It then triggers the corresponding
> registered callbacks.

You should configure your editor to use a full 80-char width. Why stop
at ~50? When you're unsure, look at that other commit logs from other
developers. If yours doesn't look similar, its probably a problem. For
example:

"Add support for SDM (Secure Device Manager) mailbox doorbell interrupt
for async transactions. On interrupt, a workqueue is triggered which
polls the ATF for pending responses and retrieves the bitmap of all
retrieved and unprocessed transaction ids of mailbox responses from SDM.
It then triggers the corresponding registered callbacks."

> 
> Signed-off-by: Mahesh Rao <mahesh.rao@...era.com>
> Reviewed-by: Matthew Gerlach <matthew.gerlach@...era.com>
> ---
>   drivers/firmware/stratix10-svc.c             | 117 ++++++++++++++++++++++++---
>   include/linux/firmware/intel/stratix10-smc.h |  23 ++++++
>   2 files changed, 130 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/firmware/stratix10-svc.c b/drivers/firmware/stratix10-svc.c
> index 491a8149033f975d515444f025723658c51aa1fe..a65c64c1be61d9f1fd27114d7f30d7a759e8201e 100644
> --- a/drivers/firmware/stratix10-svc.c
> +++ b/drivers/firmware/stratix10-svc.c
> @@ -9,12 +9,14 @@
>   #include <linux/delay.h>
>   #include <linux/genalloc.h>
>   #include <linux/hashtable.h>
> +#include <linux/interrupt.h>
>   #include <linux/io.h>
>   #include <linux/kfifo.h>
>   #include <linux/kthread.h>
>   #include <linux/module.h>
>   #include <linux/mutex.h>
>   #include <linux/of.h>
> +#include <linux/of_irq.h>
>   #include <linux/of_platform.h>
>   #include <linux/platform_device.h>
>   #include <linux/slab.h>
> @@ -22,6 +24,7 @@
>   #include <linux/firmware/intel/stratix10-smc.h>
>   #include <linux/firmware/intel/stratix10-svc-client.h>
>   #include <linux/types.h>
> +#include <linux/workqueue.h>
>   
>   /**
>    * SVC_NUM_DATA_IN_FIFO - number of struct stratix10_svc_data in the FIFO
> @@ -213,6 +216,7 @@ struct stratix10_async_chan {
>    *                               asynchronous operations
>    * @initialized: Flag indicating whether the control structure has
>    *               been initialized
> + * @irq: Interrupt request number associated with the asynchronous control
>    * @invoke_fn: Function pointer for invoking Stratix10 service calls
>    *             to EL3 secure firmware
>    * @async_id_pool: Pointer to the ID pool used for asynchronous
> @@ -223,11 +227,13 @@ struct stratix10_async_chan {
>    *                     structure
>    * @trx_list_wr_lock: Spinlock for protecting the transaction list
>    *                    write operations
> + * @async_work: Work structure for scheduling asynchronous work
>    * @trx_list: Hash table for managing asynchronous transactions
>    */
>   
>   struct stratix10_async_ctrl {
>   	bool initialized;
> +	int irq;
>   	void (*invoke_fn)(struct stratix10_async_ctrl *actrl,
>   			  const struct arm_smccc_1_2_regs *args,
>   			  struct arm_smccc_1_2_regs *res);
> @@ -236,6 +242,7 @@ struct stratix10_async_ctrl {
>   	struct stratix10_async_chan *common_async_chan;
>   	/* spinlock to protect the writes to trx_list hash table */
>   	spinlock_t trx_list_wr_lock;
> +	struct work_struct async_work;
>   	DECLARE_HASHTABLE(trx_list, ASYNC_TRX_HASH_BITS);
>   };
>   
> @@ -1709,14 +1716,81 @@ static inline void stratix10_smc_1_2(struct stratix10_async_ctrl *actrl,
>   	arm_smccc_1_2_smc(args, res);
>   }
>   
> +static irqreturn_t stratix10_svc_async_irq_handler(int irq, void *dev_id)
> +{
> +	struct stratix10_svc_controller *ctrl = dev_id;
> +	struct stratix10_async_ctrl *actrl = &ctrl->actrl;
> +
> +	queue_work(system_bh_wq, &actrl->async_work);
> +	disable_irq_nosync(actrl->irq);
> +	return IRQ_HANDLED;
> +}

Add a newline here.

> +/**
> + * stratix10_async_workqueue_handler - Handler for the asynchronous
> + * workqueue in Stratix10 service controller.
> + * @work: Pointer to the work structure that contains the asynchronous
> + *        workqueue handler.
> + * This function is the handler for the asynchronous workqueue. It performs
> + * the following tasks:
> + * - Invokes the asynchronous polling on interrupt supervisory call.
> + * - On success,it retrieves the bitmap of pending transactions from mailbox
> + *   fifo in ATF.
> + * - It processes each pending transaction by calling the corresponding
> + *   callback function.
> + *
> + * The function ensures that the IRQ is enabled after processing the transactions
> + * and logs the total time taken to handle the transactions along with the number
> + * of transactions handled and the CPU on which the handler ran.
> + */
> +static void stratix10_async_workqueue_handler(struct work_struct *work)
> +{
> +	struct stratix10_async_ctrl *actrl =
> +		container_of(work, struct stratix10_async_ctrl, async_work);
> +	struct arm_smccc_1_2_regs
> +		args = { .a0 = INTEL_SIP_SMC_ASYNC_POLL_ON_IRQ }, res;
> +	DECLARE_BITMAP(pend_on_irq, TOTAL_TRANSACTION_IDS);
> +	struct stratix10_svc_async_handler *handler;
> +	unsigned long transaction_id = 0;
> +	u64 bitmap_array[4];
> +
> +	actrl->invoke_fn(actrl, &args, &res);
> +	if (res.a0 == INTEL_SIP_SMC_STATUS_OK) {
> +		bitmap_array[0] = res.a1;
> +		bitmap_array[1] = res.a2;
> +		bitmap_array[2] = res.a3;
> +		bitmap_array[3] = res.a4;
> +		bitmap_from_arr64(pend_on_irq, bitmap_array, TOTAL_TRANSACTION_IDS);
> +		rcu_read_lock();
> +		do {
> +			transaction_id = find_next_bit(pend_on_irq,
> +						       TOTAL_TRANSACTION_IDS,
> +						       transaction_id);
> +			if (transaction_id >= TOTAL_TRANSACTION_IDS)
> +				break;
> +			hash_for_each_possible_rcu_notrace(actrl->trx_list,
> +							   handler, next,
> +							   transaction_id) {
> +				if (handler->transaction_id == transaction_id) {
> +					handler->cb(handler->cb_arg);
> +					break;
> +				}
> +			}
> +			transaction_id++;
> +		} while (transaction_id < TOTAL_TRANSACTION_IDS);
> +		rcu_read_unlock();
> +	}
> +	enable_irq(actrl->irq);
> +}
> +
>   /**
>    * stratix10_svc_async_init - Initialize the Stratix10 service
>    *                            controller for asynchronous operations.
>    * @controller: Pointer to the Stratix10 service controller structure.
>    *
>    * This function initializes the asynchronous service controller by
> - * setting up the necessary data structures and initializing the
> - * transaction list.
> + * setting up the necessary data structures ,initializing the
> + * transaction list and registering the IRQ handler for asynchronous
> + * transactions.
>    *
>    * Return: 0 on success, -EINVAL if the controller is NULL or already
>    *         initialized, -ENOMEM if memory allocation fails,
> @@ -1728,7 +1802,7 @@ static int stratix10_svc_async_init(struct stratix10_svc_controller *controller)
>   	struct stratix10_async_ctrl *actrl;
>   	struct arm_smccc_res res;
>   	struct device *dev;
> -	int ret;
> +	int ret, irq;
>   
>   	if (!controller)
>   		return -EINVAL;
> @@ -1775,6 +1849,22 @@ static int stratix10_svc_async_init(struct stratix10_svc_controller *controller)
>   	hash_init(actrl->trx_list);
>   	atomic_set(&actrl->common_achan_refcount, 0);
>   
> +	irq = of_irq_get(dev_of_node(dev), 0);
> +	if (irq < 0) {

0 is a failing value as well.

> +		dev_warn(dev, "Failed to get IRQ, falling back to polling mode\n");
> +	} else {
> +		ret = devm_request_any_context_irq(dev, irq, stratix10_svc_async_irq_handler,
> +						   IRQF_NO_AUTOEN, "stratix10_svc", controller);
> +		if (ret == 0) {
> +			dev_alert(dev,
> +				  "Registered IRQ %d for sip async operations\n",
> +				irq);
> +			actrl->irq = irq;
> +			INIT_WORK(&actrl->async_work, stratix10_async_workqueue_handler);
> +			enable_irq(actrl->irq);
> +		}
> +	}
> +
>   	actrl->initialized = true;
>   	return 0;
>   }
> @@ -1784,13 +1874,14 @@ static int stratix10_svc_async_init(struct stratix10_svc_controller *controller)
>    *                            service controller
>    * @ctrl: Pointer to the stratix10_svc_controller structure
>    *
> - * This function performs the necessary cleanup for the asynchronous
> - * service controller. It checks if the controller is valid and if it
> - * has been initialized. It then locks the transaction list and safely
> - * removes and deallocates each handler in the list. The function also
> - * removes any asynchronous clients associated with the controller's
> - * channels and destroys the asynchronous ID pool. Finally, it resets
> - * the asynchronous ID pool and invoke function pointers to NULL.
> + * This function performs the necessary cleanup for the asynchronous service
> + * controller. It checks if the controller is valid and if it has been
> + * initialized. Also If the controller has an IRQ assigned, it frees the IRQ
> + * and flushes any pending asynchronous work. It then locks the transaction
> + * list and safely removes and deallocates each handler in the list.
> + * The function also removes any asynchronous clients associated with the
> + * controller's channels and destroys the asynchronous ID pool. Finally, it
> + * resets the asynchronous ID pool and invoke function pointers to NULL.

Did you mean to repeat the same paragraph twice?

Dinh

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