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soc: qcom: smem: better track SMEM uninitialized state

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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: Christian Marangi <ansuelsmth@gmail.com>
Link: https://lore.kernel.org/r/20251031130835.7953-3-ansuelsmth@gmail.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
This commit is contained in:
Christian Marangi
2025-10-31 14:08:33 +01:00
committed by Bjorn Andersson
parent 652a86b24c
commit 7a94d5f31b
1 changed files with 15 additions and 11 deletions
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26
drivers/soc/qcom/smem.c
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@@ -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 @@ invalid_canary:
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);