Tegra: smmu: make the context save sequence robust
This patch sanity checks the SMMU context created by the platform
code. The first entry contains the size of the array; which the
driver now verifies before moving on with the save.
This patch also fixes an error in the calculation of the size of
the context that gets copied to TZDRAM.
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
diff --git a/plat/nvidia/tegra/common/drivers/smmu/smmu.c b/plat/nvidia/tegra/common/drivers/smmu/smmu.c
index e8b0d0b..a985532 100644
--- a/plat/nvidia/tegra/common/drivers/smmu/smmu.c
+++ b/plat/nvidia/tegra/common/drivers/smmu/smmu.c
@@ -87,7 +87,7 @@
*/
void tegra_smmu_save_context(uint64_t smmu_ctx_addr)
{
- uint32_t i;
+ uint32_t i, num_entries = 0;
smmu_regs_t *smmu_ctx_regs;
#if DEBUG
plat_params_from_bl2_t *params_from_bl2 = bl31_get_plat_params();
@@ -110,13 +110,29 @@
smmu_ctx_regs = plat_get_smmu_ctx();
assert(smmu_ctx_regs);
+ /*
+ * smmu_ctx_regs[0].val contains the size of the context table minus
+ * the last entry. Sanity check the table size before we start with
+ * the context save operation.
+ */
+ while (smmu_ctx_regs[num_entries].val != 0xFFFFFFFFU) {
+ num_entries++;
+ }
+
+ /* panic if the sizes do not match */
+ if (num_entries != smmu_ctx_regs[0].val)
+ panic();
+
/* save SMMU register values */
- for (i = 1; i < smmu_ctx_regs[0].val; i++)
+ for (i = 1; i < num_entries; i++)
smmu_ctx_regs[i].val = mmio_read_32(smmu_ctx_regs[i].reg);
+ /* increment by 1 to take care of the last entry */
+ num_entries++;
+
/* Save SMMU config settings */
memcpy16((void *)(uintptr_t)smmu_ctx_addr, (void *)smmu_ctx_regs,
- sizeof(smmu_regs_t));
+ (sizeof(smmu_regs_t) * num_entries));
/* save the SMMU table address */
mmio_write_32(TEGRA_SCRATCH_BASE + SECURE_SCRATCH_RSV11_LO,