[PATCH 1/2] soc: qcom: smem: introduce qcom_smem_validate_item API

[Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>]

When a SMEM item is allocated or retrieved, sanity check on the SMEM item
is performed and backtrace is printed if the SMEM item is invalid.

Image version table in SMEM contains version details for the first 32
images. Beyond that, another SMEM item 667 is being used, which may not
be defined in all the platforms. So directly retrieving the SMEM item 667,
throws the warning as invalid item number.

To handle such cases, introduce a new API to validate the SMEM item before
processing it. While at it, make use of this API in the SMEM driver where
possible.

Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>
---
 drivers/soc/qcom/smem.c       | 16 ++++++++++++++--
 include/linux/soc/qcom/smem.h |  1 +
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
index c4c45f15dca4fb14f97df4ad494c1189e4f098bd..8a0a832f1e9915b2177a0fe08298ffe8a779e516 100644
--- a/drivers/soc/qcom/smem.c
+++ b/drivers/soc/qcom/smem.c
@@ -396,6 +396,18 @@ bool qcom_smem_is_available(void)
 }
 EXPORT_SYMBOL_GPL(qcom_smem_is_available);
 
+/**
+ * qcom_smem_validate_item() - Check if SMEM item is within the limit
+ * @item:	SMEM item to validate
+ *
+ * Return: true if SMEM item is valid, false otherwise.
+ */
+bool qcom_smem_validate_item(unsigned item)
+{
+	return item < __smem->item_count;
+}
+EXPORT_SYMBOL_GPL(qcom_smem_validate_item);
+
 static int qcom_smem_alloc_private(struct qcom_smem *smem,
 				   struct smem_partition *part,
 				   unsigned item,
@@ -517,7 +529,7 @@ int qcom_smem_alloc(unsigned host, unsigned item, size_t size)
 		return -EINVAL;
 	}
 
-	if (WARN_ON(item >= __smem->item_count))
+	if (WARN_ON(!qcom_smem_validate_item(item)))
 		return -EINVAL;
 
 	ret = hwspin_lock_timeout_irqsave(__smem->hwlock,
@@ -690,7 +702,7 @@ void *qcom_smem_get(unsigned host, unsigned item, size_t *size)
 	if (!__smem)
 		return ptr;
 
-	if (WARN_ON(item >= __smem->item_count))
+	if (WARN_ON(!qcom_smem_validate_item(item)))
 		return ERR_PTR(-EINVAL);
 
 	if (host < SMEM_HOST_COUNT && __smem->partitions[host].virt_base) {
diff --git a/include/linux/soc/qcom/smem.h b/include/linux/soc/qcom/smem.h
index f946e3beca215548ac56dbf779138d05479712f5..05891532d530a25747afb8dc96ad4ba668598197 100644
--- a/include/linux/soc/qcom/smem.h
+++ b/include/linux/soc/qcom/smem.h
@@ -5,6 +5,7 @@
 #define QCOM_SMEM_HOST_ANY -1
 
 bool qcom_smem_is_available(void);
+bool qcom_smem_validate_item(unsigned item);
 int qcom_smem_alloc(unsigned host, unsigned item, size_t size);
 void *qcom_smem_get(unsigned host, unsigned item, size_t *size);
 

-- 
2.34.1