Commit 7a94d5f3 authored by Christian Marangi's avatar Christian Marangi Committed by Bjorn Andersson
Browse files

soc: qcom: smem: better track SMEM uninitialized state 



There is currently a problem where, in the specific case of SMEM not
initialized by SBL, any SMEM API wrongly returns PROBE_DEFER
communicating wrong info to any user of this API.

A better way to handle this would be to track the SMEM state and return
a different kind of error than PROBE_DEFER.

Rework the __smem handle to always init it to the error pointer
-EPROBE_DEFER following what is already done by the SMEM API.
If we detect that the SBL didn't initialized SMEM, set the __smem handle
to the error pointer -ENODEV.
Also rework the SMEM API to handle the __smem handle to be an error
pointer and return it appropriately.

This way user of the API can react and return a proper error or use
fallback way for the failing API.

While at it, change the return error when SMEM is not initialized by SBL
also to -ENODEV to make it consistent with the __smem handle and use
dev_err_probe() helper to return the message.

Signed-off-by: default avatarChristian Marangi <ansuelsmth@gmail.com>
Link: https://lore.kernel.org/r/20251031130835.7953-3-ansuelsmth@gmail.com


Signed-off-by: default avatarBjorn Andersson <andersson@kernel.org>
parent 652a86b2

drivers/soc/qcom/smem.c

+15 −11
Original line number Diff line number Diff line
@@ -353,8 +353,12 @@ static void *cached_entry_to_item(struct smem_private_entry *e) 
	return p - le32_to_cpu(e->size);

}



/* Pointer to the one and only smem handle */

static struct qcom_smem *__smem;

/*

 * Pointer to the one and only smem handle.

 * Init to -EPROBE_DEFER to signal SMEM still has to be probed.

 * Can be set to -ENODEV if SMEM is not initialized by SBL.

 */

static struct qcom_smem *__smem = INIT_ERR_PTR(-EPROBE_DEFER);



/* Timeout (ms) for the trylock of remote spinlocks */

#define HWSPINLOCK_TIMEOUT	1000
@@ -508,8 +512,8 @@ int qcom_smem_alloc(unsigned host, unsigned item, size_t size) 
	unsigned long flags;

	int ret;



	if (!__smem)

		return -EPROBE_DEFER;

	if (IS_ERR(__smem))

		return PTR_ERR(__smem);



	if (item < SMEM_ITEM_LAST_FIXED) {

		dev_err(__smem->dev,
@@ -685,10 +689,10 @@ static void *qcom_smem_get_private(struct qcom_smem *smem, 
void *qcom_smem_get(unsigned host, unsigned item, size_t *size)

{

	struct smem_partition *part;

	void *ptr = ERR_PTR(-EPROBE_DEFER);

	void *ptr;



	if (!__smem)

		return ptr;

	if (IS_ERR(__smem))

		return __smem;



	if (WARN_ON(item >= __smem->item_count))

		return ERR_PTR(-EINVAL);
@@ -723,8 +727,8 @@ int qcom_smem_get_free_space(unsigned host) 
	struct smem_header *header;

	unsigned ret;



	if (!__smem)

		return -EPROBE_DEFER;

	if (IS_ERR(__smem))

		return PTR_ERR(__smem);



	if (host < SMEM_HOST_COUNT && __smem->partitions[host].virt_base) {

		part = &__smem->partitions[host];
@@ -1181,8 +1185,8 @@ static int qcom_smem_probe(struct platform_device *pdev) 
	header = smem->regions[0].virt_base;

	if (le32_to_cpu(header->initialized) != 1 ||

	    le32_to_cpu(header->reserved)) {

		dev_err(&pdev->dev, "SMEM is not initialized by SBL\n");

		return -EINVAL;

		__smem = ERR_PTR(-ENODEV);

		return dev_err_probe(&pdev->dev, PTR_ERR(__smem), "SMEM is not initialized by SBL\n");

	}



	hwlock_id = of_hwspin_lock_get_id(pdev->dev.of_node, 0);