Commit 61824fea authored by Sudeep Holla's avatar Sudeep Holla
Browse files

firmware: arm_ffa: Fetch the Rx/Tx buffer size using ffa_features() 



An endpoint can discover the minimum size, maximum size and alignment
boundary for the Rx/Tx buffers by passing the function ID of the
FFA_RXTX_MAP ABI as input in the FFA_FEATURES interface. The maximum
size is an optional field and a value of 0 means that the partition
manager or the hypervisor does not enforce a maximum size.

Use the discovery mechanism and remove the hardcoded 4kB buffer size.
If the discovery fails, it still defaults to 4kB.

Message-Id: <20240820-ffa_v1-2-v2-7-18c0c5f3c65e@arm.com>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
parent eaca7ef8

drivers/firmware/arm_ffa/driver.c

+28 −16
Original line number Diff line number Diff line
@@ -54,11 +54,8 @@ 
#define PACK_TARGET_INFO(s, r)		\

	(FIELD_PREP(SENDER_ID_MASK, (s)) | FIELD_PREP(RECEIVER_ID_MASK, (r)))



/*

 * Keeping RX TX buffer size as 4K for now

 * 64K may be preferred to keep it min a page in 64K PAGE_SIZE config

 */

#define RXTX_BUFFER_SIZE	SZ_4K

#define RXTX_MAP_MIN_BUFSZ_MASK	GENMASK(1, 0)

#define RXTX_MAP_MIN_BUFSZ(x)	((x) & RXTX_MAP_MIN_BUFSZ_MASK)



#define FFA_MAX_NOTIFICATIONS		64
@@ -99,6 +96,7 @@ struct ffa_drv_info { 
	struct mutex tx_lock; /* lock to protect Tx buffer */

	void *rx_buffer;

	void *tx_buffer;

	size_t rxtx_bufsz;

	bool mem_ops_native;

	bool msg_direct_req2_supp;

	bool bitmap_created;
@@ -454,7 +452,7 @@ static int ffa_msg_send2(u16 src_id, u16 dst_id, void *buf, size_t sz) 
	ffa_value_t ret;

	int retval = 0;



	if (sz > (RXTX_BUFFER_SIZE - sizeof(*msg)))

	if (sz > (drv_info->rxtx_bufsz - sizeof(*msg)))

		return -ERANGE;



	mutex_lock(&drv_info->tx_lock);
@@ -689,9 +687,10 @@ static int ffa_memory_ops(u32 func_id, struct ffa_mem_ops_args *args) 
{

	int ret;

	void *buffer;

	size_t rxtx_bufsz = drv_info->rxtx_bufsz;



	if (!args->use_txbuf) {

		buffer = alloc_pages_exact(RXTX_BUFFER_SIZE, GFP_KERNEL);

		buffer = alloc_pages_exact(rxtx_bufsz, GFP_KERNEL);

		if (!buffer)

			return -ENOMEM;

	} else {
@@ -699,12 +698,12 @@ static int ffa_memory_ops(u32 func_id, struct ffa_mem_ops_args *args) 
		mutex_lock(&drv_info->tx_lock);

	}



	ret = ffa_setup_and_transmit(func_id, buffer, RXTX_BUFFER_SIZE, args);

	ret = ffa_setup_and_transmit(func_id, buffer, rxtx_bufsz, args);



	if (args->use_txbuf)

		mutex_unlock(&drv_info->tx_lock);

	else

		free_pages_exact(buffer, RXTX_BUFFER_SIZE);

		free_pages_exact(buffer, rxtx_bufsz);



	return ret < 0 ? ret : 0;

}
@@ -1718,6 +1717,8 @@ static void ffa_notifications_setup(void) 
static int __init ffa_init(void)

{

	int ret;

	u32 buf_sz;

	size_t rxtx_bufsz = SZ_4K;



	ret = ffa_transport_init(&invoke_ffa_fn);

	if (ret)
@@ -1737,13 +1738,24 @@ static int __init ffa_init(void) 
		goto free_drv_info;

	}



	drv_info->rx_buffer = alloc_pages_exact(RXTX_BUFFER_SIZE, GFP_KERNEL);

	ret = ffa_features(FFA_FN_NATIVE(RXTX_MAP), 0, &buf_sz, NULL);

	if (!ret) {

		if (RXTX_MAP_MIN_BUFSZ(buf_sz) == 1)

			rxtx_bufsz = SZ_64K;

		else if (RXTX_MAP_MIN_BUFSZ(buf_sz) == 2)

			rxtx_bufsz = SZ_16K;

		else

			rxtx_bufsz = SZ_4K;

	}



	drv_info->rxtx_bufsz = rxtx_bufsz;

	drv_info->rx_buffer = alloc_pages_exact(rxtx_bufsz, GFP_KERNEL);

	if (!drv_info->rx_buffer) {

		ret = -ENOMEM;

		goto free_pages;

	}



	drv_info->tx_buffer = alloc_pages_exact(RXTX_BUFFER_SIZE, GFP_KERNEL);

	drv_info->tx_buffer = alloc_pages_exact(rxtx_bufsz, GFP_KERNEL);

	if (!drv_info->tx_buffer) {

		ret = -ENOMEM;

		goto free_pages;
@@ -1751,7 +1763,7 @@ static int __init ffa_init(void) 


	ret = ffa_rxtx_map(virt_to_phys(drv_info->tx_buffer),

			   virt_to_phys(drv_info->rx_buffer),

			   RXTX_BUFFER_SIZE / FFA_PAGE_SIZE);

			   rxtx_bufsz / FFA_PAGE_SIZE);

	if (ret) {

		pr_err("failed to register FFA RxTx buffers\n");

		goto free_pages;
@@ -1781,8 +1793,8 @@ static int __init ffa_init(void) 
	ffa_notifications_cleanup();

free_pages:

	if (drv_info->tx_buffer)

		free_pages_exact(drv_info->tx_buffer, RXTX_BUFFER_SIZE);

	free_pages_exact(drv_info->rx_buffer, RXTX_BUFFER_SIZE);

		free_pages_exact(drv_info->tx_buffer, rxtx_bufsz);

	free_pages_exact(drv_info->rx_buffer, rxtx_bufsz);

free_drv_info:

	kfree(drv_info);

	return ret;
@@ -1794,8 +1806,8 @@ static void __exit ffa_exit(void) 
	ffa_notifications_cleanup();

	ffa_partitions_cleanup();

	ffa_rxtx_unmap(drv_info->vm_id);

	free_pages_exact(drv_info->tx_buffer, RXTX_BUFFER_SIZE);

	free_pages_exact(drv_info->rx_buffer, RXTX_BUFFER_SIZE);

	free_pages_exact(drv_info->tx_buffer, drv_info->rxtx_bufsz);

	free_pages_exact(drv_info->rx_buffer, drv_info->rxtx_bufsz);

	kfree(drv_info);

}

module_exit(ffa_exit);