[PATCH resend 07/12] soc: qcom: smem: introduce qcom_smem_partition_header()

From: Alex Elder
Date: Mon Jun 25 2018 - 21:00:37 EST


Create a new function qcom_smem_partition_header() to encapsulate
validating locating a partition header and validating information
found within it. This will be built up over a few commits to make
it more obvious how the common function is replacing duplicated code
elsewhere. Initially it just verifies the header has the right
magic number.

Signed-off-by: Alex Elder <elder@xxxxxxxxxx>
---
drivers/soc/qcom/smem.c | 45 ++++++++++++++++++++++++++++-------------
1 file changed, 31 insertions(+), 14 deletions(-)

diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
index 49f228e9d2d3..516a17d340af 100644
--- a/drivers/soc/qcom/smem.c
+++ b/drivers/soc/qcom/smem.c
@@ -727,6 +727,29 @@ static u32 qcom_smem_get_item_count(struct qcom_smem *smem)
return le16_to_cpu(info->num_items);
}

+/*
+ * Validate the partition header for a partition whose partition
+ * table entry is supplied. Returns a pointer to its header if
+ * valid, or a null pointer otherwise.
+ */
+static struct smem_partition_header *
+qcom_smem_partition_header(struct qcom_smem *smem,
+ struct smem_ptable_entry *entry)
+{
+ struct smem_partition_header *header;
+
+ header = smem->regions[0].virt_base + le32_to_cpu(entry->offset);
+
+ if (memcmp(header->magic, SMEM_PART_MAGIC, sizeof(header->magic))) {
+ dev_err(smem->dev, "bad partition magic %02x %02x %02x %02x\n",
+ header->magic[0], header->magic[1],
+ header->magic[2], header->magic[3]);
+ return NULL;
+ }
+
+ return header;
+}
+
static int qcom_smem_set_global_partition(struct qcom_smem *smem)
{
struct smem_partition_header *header;
@@ -760,15 +783,13 @@ static int qcom_smem_set_global_partition(struct qcom_smem *smem)
return -EINVAL;
}

- header = smem->regions[0].virt_base + le32_to_cpu(entry->offset);
+ header = qcom_smem_partition_header(smem, entry);
+ if (!header)
+ return -EINVAL;
+
host0 = le16_to_cpu(header->host0);
host1 = le16_to_cpu(header->host1);

- if (memcmp(header->magic, SMEM_PART_MAGIC, sizeof(header->magic))) {
- dev_err(smem->dev, "Global partition has invalid magic\n");
- return -EINVAL;
- }
-
if (host0 != SMEM_GLOBAL_HOST || host1 != SMEM_GLOBAL_HOST) {
dev_err(smem->dev, "Global partition hosts are invalid\n");
return -EINVAL;
@@ -836,17 +857,13 @@ static int qcom_smem_enumerate_partitions(struct qcom_smem *smem,
return -EINVAL;
}

- header = smem->regions[0].virt_base + le32_to_cpu(entry->offset);
+ header = qcom_smem_partition_header(smem, entry);
+ if (!header)
+ return -EINVAL;
+
host0 = le16_to_cpu(header->host0);
host1 = le16_to_cpu(header->host1);

- if (memcmp(header->magic, SMEM_PART_MAGIC,
- sizeof(header->magic))) {
- dev_err(smem->dev,
- "Partition %d has invalid magic\n", i);
- return -EINVAL;
- }
-
if (host0 != host0 || host1 != host1) {
dev_err(smem->dev,
"Partition %d hosts don't match\n", i);
--
2.17.1