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

From: Arun Kumar Neelakantam
Date: Mon Aug 21 2017 - 04:57:42 EST




On 8/18/2017 6:45 AM, Chris Lew wrote:
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@xxxxxxxxxxxxxx>
---
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;
The num_items is first 16bits of reserved field, we dont have 32bit reserved and 32 bit for 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))
can you please add this item_count check from partition alloc/get also if avoid any unknown clients usage of smem
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;