media: venus: firmware: check fw size against DT memory region size

By historical reasons we defined firmware memory size to be 6MB even
that the firmware size for all supported Venus versions is 5MBs. Correct
that by compare the required firmware size returned from mdt loader and
the one provided by DT reserved memory region. We proceed further if the
required firmware size is smaller than provided by DT memory region.
Reviewed-by: Alexandre Courbot <acourbot@chromium.org>
Tested-by: Alexandre Courbot <acourbot@chromium.org>
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/platform/qcom/venus/core.h

@@ -134,6 +134,7 @@ struct venus_core {
 	struct video_firmware {
 		struct device *dev;
 		struct iommu_domain *iommu_domain;
+		size_t mapped_mem_size;
 	} fw;
 	struct mutex lock;
 	struct list_head instances;

drivers/media/platform/qcom/venus/firmware.c

@@ -35,14 +35,15 @@
 
 static void venus_reset_cpu(struct venus_core *core)
 {
+	u32 fw_size = core->fw.mapped_mem_size;
 	void __iomem *base = core->base;
 
 	writel(0, base + WRAPPER_FW_START_ADDR);
-	writel(VENUS_FW_MEM_SIZE, base + WRAPPER_FW_END_ADDR);
+	writel(fw_size, base + WRAPPER_FW_END_ADDR);
 	writel(0, base + WRAPPER_CPA_START_ADDR);
-	writel(VENUS_FW_MEM_SIZE, base + WRAPPER_CPA_END_ADDR);
-	writel(VENUS_FW_MEM_SIZE, base + WRAPPER_NONPIX_START_ADDR);
-	writel(VENUS_FW_MEM_SIZE, base + WRAPPER_NONPIX_END_ADDR);
+	writel(fw_size, base + WRAPPER_CPA_END_ADDR);
+	writel(fw_size, base + WRAPPER_NONPIX_START_ADDR);
+	writel(fw_size, base + WRAPPER_NONPIX_END_ADDR);
 	writel(0x0, base + WRAPPER_CPU_CGC_DIS);
 	writel(0x0, base + WRAPPER_CPU_CLOCK_CONFIG);
 
@@ -74,6 +75,9 @@ static int venus_load_fw(struct venus_core *core, const char *fwname,
 	void *mem_va;
 	int ret;
 
+	*mem_phys = 0;
+	*mem_size = 0;
+
 	dev = core->dev;
 	node = of_parse_phandle(dev->of_node, "memory-region", 0);
 	if (!node) {
@@ -85,28 +89,30 @@ static int venus_load_fw(struct venus_core *core, const char *fwname,
 	if (ret)
 		return ret;
 
+	ret = request_firmware(&mdt, fwname, dev);
+	if (ret < 0)
+		return ret;
+
+	fw_size = qcom_mdt_get_size(mdt);
+	if (fw_size < 0) {
+		ret = fw_size;
+		goto err_release_fw;
+	}
+
 	*mem_phys = r.start;
 	*mem_size = resource_size(&r);
 
-	if (*mem_size < VENUS_FW_MEM_SIZE)
-		return -EINVAL;
+	if (*mem_size < fw_size || fw_size > VENUS_FW_MEM_SIZE) {
+		ret = -EINVAL;
+		goto err_release_fw;
+	}
 
 	mem_va = memremap(r.start, *mem_size, MEMREMAP_WC);
 	if (!mem_va) {
 		dev_err(dev, "unable to map memory region: %pa+%zx\n",
 			&r.start, *mem_size);
-		return -ENOMEM;
-	}
-
-	ret = request_firmware(&mdt, fwname, dev);
-	if (ret < 0)
-		goto err_unmap;
-
-	fw_size = qcom_mdt_get_size(mdt);
-	if (fw_size < 0) {
-		ret = fw_size;
-		release_firmware(mdt);
-		goto err_unmap;
+		ret = -ENOMEM;
+		goto err_release_fw;
 	}
 
 	if (core->use_tz)
@@ -116,10 +122,9 @@ static int venus_load_fw(struct venus_core *core, const char *fwname,
 		ret = qcom_mdt_load_no_init(dev, mdt, fwname, VENUS_PAS_ID,
 					    mem_va, *mem_phys, *mem_size, NULL);
 
-	release_firmware(mdt);
-
-err_unmap:
 	memunmap(mem_va);
+err_release_fw:
+	release_firmware(mdt);
 	return ret;
 }
 
@@ -135,6 +140,7 @@ static int venus_boot_no_tz(struct venus_core *core, phys_addr_t mem_phys,
 		return -EPROBE_DEFER;
 
 	iommu = core->fw.iommu_domain;
+	core->fw.mapped_mem_size = mem_size;
 
 	ret = iommu_map(iommu, VENUS_FW_START_ADDR, mem_phys, mem_size,
 			IOMMU_READ | IOMMU_WRITE | IOMMU_PRIV);
@@ -150,6 +156,7 @@ static int venus_boot_no_tz(struct venus_core *core, phys_addr_t mem_phys,
 
 static int venus_shutdown_no_tz(struct venus_core *core)
 {
+	const size_t mapped = core->fw.mapped_mem_size;
 	struct iommu_domain *iommu;
 	size_t unmapped;
 	u32 reg;
@@ -166,8 +173,8 @@ static int venus_shutdown_no_tz(struct venus_core *core)
 
 	iommu = core->fw.iommu_domain;
 
-	unmapped = iommu_unmap(iommu, VENUS_FW_START_ADDR, VENUS_FW_MEM_SIZE);
-	if (unmapped != VENUS_FW_MEM_SIZE)
+	unmapped = iommu_unmap(iommu, VENUS_FW_START_ADDR, mapped);
+	if (unmapped != mapped)
 		dev_err(dev, "failed to unmap firmware\n");
 
 	return 0;