[PATCH 2/3] soc: qcom: smem: Support dynamic item limit

[Chris Lew <clew@codeaurora.org>]

In V12 SMEM, SBL writes SMEM parameter information
after the TOC. Use the SBL provided item count
as the max item number.

Signed-off-by: Chris Lew <clew@codeaurora.org>
---
 drivers/soc/qcom/smem.c | 41 +++++++++++++++++++++++++++++++++++++++--
 1 file changed, 39 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
index fed2934d6bda..a51f4ba42173 100644
--- a/drivers/soc/qcom/smem.c
+++ b/drivers/soc/qcom/smem.c
@@ -225,6 +225,24 @@ struct smem_private_entry {
 #define SMEM_PRIVATE_CANARY	0xa5a5
 
 /**
+ * struct smem_info - smem region info located after the table of contents
+ * @magic:	magic number, must be SMEM_INFO_MAGIC
+ * @size:	size of the smem region
+ * @base_addr:	base address of the smem region
+ * @reserved: for now reserved entry
+ * @num_items: highest accepted item number
+ */
+struct smem_info {
+	u8 magic[4];
+	__le32 size;
+	__le32 base_addr;
+	__le32 reserved;
+	__le32 num_items;
+};
+
+static const u8 SMEM_INFO_MAGIC[] = { 0x53, 0x49, 0x49, 0x49 }; /* SIII */
+
+/**
  * struct smem_region - representation of a chunk of memory used for smem
  * @aux_base:	identifier of aux_mem base
  * @virt_base:	virtual base address of memory with this aux_mem identifier
@@ -245,6 +263,7 @@ struct smem_region {
  * @partitions:	list of pointers to partitions affecting the current
  *		processor/host
  * @cacheline:	list of cacheline sizes for each host
+ * @item_count: max accepted item number
  * @num_regions: number of @regions
  * @regions:	list of the memory regions defining the shared memory
  */
@@ -257,6 +276,7 @@ struct qcom_smem {
 	size_t global_cacheline;
 	struct smem_partition_header *partitions[SMEM_HOST_COUNT];
 	size_t cacheline[SMEM_HOST_COUNT];
+	u32 item_count;
 
 	unsigned num_regions;
 	struct smem_region regions[0];
@@ -388,7 +408,7 @@ static int qcom_smem_alloc_global(struct qcom_smem *smem,
 	struct smem_header *header;
 	struct smem_global_entry *entry;
 
-	if (WARN_ON(item >= SMEM_ITEM_COUNT))
+	if (WARN_ON(item >= smem->item_count))
 		return -EINVAL;
 
 	header = smem->regions[0].virt_base;
@@ -473,7 +493,7 @@ static void *qcom_smem_get_global(struct qcom_smem *smem,
 	u32 aux_base;
 	unsigned i;
 
-	if (WARN_ON(item >= SMEM_ITEM_COUNT))
+	if (WARN_ON(item >= smem->item_count))
 		return ERR_PTR(-EINVAL);
 
 	header = smem->regions[0].virt_base;
@@ -640,6 +660,19 @@ static int qcom_smem_get_sbl_version(struct qcom_smem *smem)
 	return le32_to_cpu(versions[SMEM_MASTER_SBL_VERSION_INDEX]);
 }
 
+static u32 qcom_smem_get_dynamic_item(struct qcom_smem *smem)
+{
+	struct smem_ptable *ptable;
+	struct smem_info *info;
+
+	ptable = smem->regions[0].virt_base + smem->regions[0].size - SZ_4K;
+	info = (struct smem_info *)&ptable->entry[ptable->num_entries];
+	if (memcmp(info->magic, SMEM_INFO_MAGIC, sizeof(info->magic)))
+		return SMEM_ITEM_COUNT;
+
+	return le32_to_cpu(info->num_items);
+}
+
 static int qcom_smem_set_global_partition(struct qcom_smem *smem,
 				struct smem_ptable_entry *entry)
 {
@@ -857,7 +890,11 @@ static int qcom_smem_probe(struct platform_device *pdev)
 	version = qcom_smem_get_sbl_version(smem);
 	switch (version >> 16) {
 	case SMEM_GLOBAL_PART_VERSION:
+		smem->item_count = qcom_smem_get_dynamic_item(smem);
+		break;
 	case SMEM_GLOBAL_HEAP_VERSION:
+		smem->item_count = SMEM_ITEM_COUNT;
+		break;
 	default:
 		dev_err(&pdev->dev, "Unsupported SMEM version 0x%x\n", version);
 		return -EINVAL;
-- 
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