1 files changed, 73 insertions, 30 deletions

diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
index 93638ae2753a..4c26b19f5154 100644
--- a/drivers/misc/sram.c
+++ b/drivers/misc/sram.c
@@ -97,7 +97,24 @@ static int sram_add_partition(struct sram_dev *sram, struct sram_reserve *block,
 	struct sram_partition *part = &sram->partition[sram->partitions];
 
 	mutex_init(&part->lock);
-	part->base = sram->virt_base + block->start;
+
+	if (sram->config && sram->config->map_only_reserved) {
+		void __iomem *virt_base;
+
+		if (sram->no_memory_wc)
+			virt_base = devm_ioremap_resource(sram->dev, &block->res);
+		else
+			virt_base = devm_ioremap_resource_wc(sram->dev, &block->res);
+
+		if (IS_ERR(virt_base)) {
+			dev_err(sram->dev, "could not map SRAM at %pr\n", &block->res);
+			return PTR_ERR(virt_base);
+		}
+
+		part->base = virt_base;
+	} else {
+		part->base = sram->virt_base + block->start;
+	}
 
 	if (block->pool) {
 		ret = sram_add_pool(sram, block, start, part);
@@ -198,6 +215,7 @@ static int sram_reserve_regions(struct sram_dev *sram, struct resource *res)
 
 		block->start = child_res.start - res->start;
 		block->size = resource_size(&child_res);
+		block->res = child_res;
 		list_add_tail(&block->list, &reserve_list);
 
 		if (of_find_property(child, "export", NULL))
@@ -295,15 +313,17 @@ static int sram_reserve_regions(struct sram_dev *sram, struct resource *res)
 		 */
 		cur_size = block->start - cur_start;
 
-		dev_dbg(sram->dev, "adding chunk 0x%lx-0x%lx\n",
-			cur_start, cur_start + cur_size);
+		if (sram->pool) {
+			dev_dbg(sram->dev, "adding chunk 0x%lx-0x%lx\n",
+				cur_start, cur_start + cur_size);
 
-		ret = gen_pool_add_virt(sram->pool,
-				(unsigned long)sram->virt_base + cur_start,
-				res->start + cur_start, cur_size, -1);
-		if (ret < 0) {
-			sram_free_partitions(sram);
-			goto err_chunks;
+			ret = gen_pool_add_virt(sram->pool,
+					(unsigned long)sram->virt_base + cur_start,
+					res->start + cur_start, cur_size, -1);
+			if (ret < 0) {
+				sram_free_partitions(sram);
+				goto err_chunks;
+			}
 		}
 
 		/* next allocation after this reserved block */
@@ -331,40 +351,63 @@ static int atmel_securam_wait(void)
 					10000, 500000);
 }
 
+static const struct sram_config atmel_securam_config = {
+	.init = atmel_securam_wait,
+};
+
+/*
+ * SYSRAM contains areas that are not accessible by the
+ * kernel, such as the first 256K that is reserved for TZ.
+ * Accesses to those areas (including speculative accesses)
+ * trigger SErrors. As such we must map only the areas of
+ * SYSRAM specified in the device tree.
+ */
+static const struct sram_config tegra_sysram_config = {
+	.map_only_reserved = true,
+};
+
 static const struct of_device_id sram_dt_ids[] = {
 	{ .compatible = "mmio-sram" },
-	{ .compatible = "atmel,sama5d2-securam", .data = atmel_securam_wait },
+	{ .compatible = "atmel,sama5d2-securam", .data = &atmel_securam_config },
+	{ .compatible = "nvidia,tegra186-sysram", .data = &tegra_sysram_config },
+	{ .compatible = "nvidia,tegra194-sysram", .data = &tegra_sysram_config },
 	{}
 };
 
 static int sram_probe(struct platform_device *pdev)
 {
+	const struct sram_config *config;
 	struct sram_dev *sram;
 	int ret;
 	struct resource *res;
-	int (*init_func)(void);
+
+	config = of_device_get_match_data(&pdev->dev);
 
 	sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
 	if (!sram)
 		return -ENOMEM;
 
 	sram->dev = &pdev->dev;
+	sram->no_memory_wc = of_property_read_bool(pdev->dev.of_node, "no-memory-wc");
+	sram->config = config;
+
+	if (!config || !config->map_only_reserved) {
+		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+		if (sram->no_memory_wc)
+			sram->virt_base = devm_ioremap_resource(&pdev->dev, res);
+		else
+			sram->virt_base = devm_ioremap_resource_wc(&pdev->dev, res);
+		if (IS_ERR(sram->virt_base)) {
+			dev_err(&pdev->dev, "could not map SRAM registers\n");
+			return PTR_ERR(sram->virt_base);
+		}
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (of_property_read_bool(pdev->dev.of_node, "no-memory-wc"))
-		sram->virt_base = devm_ioremap_resource(&pdev->dev, res);
-	else
-		sram->virt_base = devm_ioremap_resource_wc(&pdev->dev, res);
-	if (IS_ERR(sram->virt_base)) {
-		dev_err(&pdev->dev, "could not map SRAM registers\n");
-		return PTR_ERR(sram->virt_base);
+		sram->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY),
+						  NUMA_NO_NODE, NULL);
+		if (IS_ERR(sram->pool))
+			return PTR_ERR(sram->pool);
 	}
 
-	sram->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY),
-					  NUMA_NO_NODE, NULL);
-	if (IS_ERR(sram->pool))
-		return PTR_ERR(sram->pool);
-
 	sram->clk = devm_clk_get(sram->dev, NULL);
 	if (IS_ERR(sram->clk))
 		sram->clk = NULL;
@@ -378,15 +421,15 @@ static int sram_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, sram);
 
-	init_func = of_device_get_match_data(&pdev->dev);
-	if (init_func) {
-		ret = init_func();
+	if (config && config->init) {
+		ret = config->init();
 		if (ret)
 			goto err_free_partitions;
 	}
 
-	dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n",
-		gen_pool_size(sram->pool) / 1024, sram->virt_base);
+	if (sram->pool)
+		dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n",
+			gen_pool_size(sram->pool) / 1024, sram->virt_base);
 
 	return 0;
 
@@ -405,7 +448,7 @@ static int sram_remove(struct platform_device *pdev)
 
 	sram_free_partitions(sram);
 
-	if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool))
+	if (sram->pool && gen_pool_avail(sram->pool) < gen_pool_size(sram->pool))
 		dev_err(sram->dev, "removed while SRAM allocated\n");
 
 	if (sram->clk)