1 files changed, 475 insertions, 0 deletions

diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
new file mode 100644
index 000000000..f0e7f0260
--- /dev/null
+++ b/drivers/misc/sram.c
@@ -0,0 +1,475 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Generic on-chip SRAM allocation driver
+ *
+ * Copyright (C) 2012 Philipp Zabel, Pengutronix
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/genalloc.h>
+#include <linux/io.h>
+#include <linux/list_sort.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/mfd/syscon.h>
+#include <soc/at91/atmel-secumod.h>
+
+#include "sram.h"
+
+#define SRAM_GRANULARITY	32
+
+static ssize_t sram_read(struct file *filp, struct kobject *kobj,
+			 struct bin_attribute *attr,
+			 char *buf, loff_t pos, size_t count)
+{
+	struct sram_partition *part;
+
+	part = container_of(attr, struct sram_partition, battr);
+
+	mutex_lock(&part->lock);
+	memcpy_fromio(buf, part->base + pos, count);
+	mutex_unlock(&part->lock);
+
+	return count;
+}
+
+static ssize_t sram_write(struct file *filp, struct kobject *kobj,
+			  struct bin_attribute *attr,
+			  char *buf, loff_t pos, size_t count)
+{
+	struct sram_partition *part;
+
+	part = container_of(attr, struct sram_partition, battr);
+
+	mutex_lock(&part->lock);
+	memcpy_toio(part->base + pos, buf, count);
+	mutex_unlock(&part->lock);
+
+	return count;
+}
+
+static int sram_add_pool(struct sram_dev *sram, struct sram_reserve *block,
+			 phys_addr_t start, struct sram_partition *part)
+{
+	int ret;
+
+	part->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY),
+					  NUMA_NO_NODE, block->label);
+	if (IS_ERR(part->pool))
+		return PTR_ERR(part->pool);
+
+	ret = gen_pool_add_virt(part->pool, (unsigned long)part->base, start,
+				block->size, NUMA_NO_NODE);
+	if (ret < 0) {
+		dev_err(sram->dev, "failed to register subpool: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int sram_add_export(struct sram_dev *sram, struct sram_reserve *block,
+			   phys_addr_t start, struct sram_partition *part)
+{
+	sysfs_bin_attr_init(&part->battr);
+	part->battr.attr.name = devm_kasprintf(sram->dev, GFP_KERNEL,
+					       "%llx.sram",
+					       (unsigned long long)start);
+	if (!part->battr.attr.name)
+		return -ENOMEM;
+
+	part->battr.attr.mode = S_IRUSR | S_IWUSR;
+	part->battr.read = sram_read;
+	part->battr.write = sram_write;
+	part->battr.size = block->size;
+
+	return device_create_bin_file(sram->dev, &part->battr);
+}
+
+static int sram_add_partition(struct sram_dev *sram, struct sram_reserve *block,
+			      phys_addr_t start)
+{
+	int ret;
+	struct sram_partition *part = &sram->partition[sram->partitions];
+
+	mutex_init(&part->lock);
+
+	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);
+		if (ret)
+			return ret;
+	}
+	if (block->export) {
+		ret = sram_add_export(sram, block, start, part);
+		if (ret)
+			return ret;
+	}
+	if (block->protect_exec) {
+		ret = sram_check_protect_exec(sram, block, part);
+		if (ret)
+			return ret;
+
+		ret = sram_add_pool(sram, block, start, part);
+		if (ret)
+			return ret;
+
+		sram_add_protect_exec(part);
+	}
+
+	sram->partitions++;
+
+	return 0;
+}
+
+static void sram_free_partitions(struct sram_dev *sram)
+{
+	struct sram_partition *part;
+
+	if (!sram->partitions)
+		return;
+
+	part = &sram->partition[sram->partitions - 1];
+	for (; sram->partitions; sram->partitions--, part--) {
+		if (part->battr.size)
+			device_remove_bin_file(sram->dev, &part->battr);
+
+		if (part->pool &&
+		    gen_pool_avail(part->pool) < gen_pool_size(part->pool))
+			dev_err(sram->dev, "removed pool while SRAM allocated\n");
+	}
+}
+
+static int sram_reserve_cmp(void *priv, const struct list_head *a,
+					const struct list_head *b)
+{
+	struct sram_reserve *ra = list_entry(a, struct sram_reserve, list);
+	struct sram_reserve *rb = list_entry(b, struct sram_reserve, list);
+
+	return ra->start - rb->start;
+}
+
+static int sram_reserve_regions(struct sram_dev *sram, struct resource *res)
+{
+	struct device_node *np = sram->dev->of_node, *child;
+	unsigned long size, cur_start, cur_size;
+	struct sram_reserve *rblocks, *block;
+	struct list_head reserve_list;
+	unsigned int nblocks, exports = 0;
+	const char *label;
+	int ret = 0;
+
+	INIT_LIST_HEAD(&reserve_list);
+
+	size = resource_size(res);
+
+	/*
+	 * We need an additional block to mark the end of the memory region
+	 * after the reserved blocks from the dt are processed.
+	 */
+	nblocks = (np) ? of_get_available_child_count(np) + 1 : 1;
+	rblocks = kcalloc(nblocks, sizeof(*rblocks), GFP_KERNEL);
+	if (!rblocks)
+		return -ENOMEM;
+
+	block = &rblocks[0];
+	for_each_available_child_of_node(np, child) {
+		struct resource child_res;
+
+		ret = of_address_to_resource(child, 0, &child_res);
+		if (ret < 0) {
+			dev_err(sram->dev,
+				"could not get address for node %pOF\n",
+				child);
+			goto err_chunks;
+		}
+
+		if (child_res.start < res->start || child_res.end > res->end) {
+			dev_err(sram->dev,
+				"reserved block %pOF outside the sram area\n",
+				child);
+			ret = -EINVAL;
+			goto err_chunks;
+		}
+
+		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))
+			block->export = true;
+
+		if (of_find_property(child, "pool", NULL))
+			block->pool = true;
+
+		if (of_find_property(child, "protect-exec", NULL))
+			block->protect_exec = true;
+
+		if ((block->export || block->pool || block->protect_exec) &&
+		    block->size) {
+			exports++;
+
+			label = NULL;
+			ret = of_property_read_string(child, "label", &label);
+			if (ret && ret != -EINVAL) {
+				dev_err(sram->dev,
+					"%pOF has invalid label name\n",
+					child);
+				goto err_chunks;
+			}
+			if (!label)
+				label = child->name;
+
+			block->label = devm_kstrdup(sram->dev,
+						    label, GFP_KERNEL);
+			if (!block->label) {
+				ret = -ENOMEM;
+				goto err_chunks;
+			}
+
+			dev_dbg(sram->dev, "found %sblock '%s' 0x%x-0x%x\n",
+				block->export ? "exported " : "", block->label,
+				block->start, block->start + block->size);
+		} else {
+			dev_dbg(sram->dev, "found reserved block 0x%x-0x%x\n",
+				block->start, block->start + block->size);
+		}
+
+		block++;
+	}
+	child = NULL;
+
+	/* the last chunk marks the end of the region */
+	rblocks[nblocks - 1].start = size;
+	rblocks[nblocks - 1].size = 0;
+	list_add_tail(&rblocks[nblocks - 1].list, &reserve_list);
+
+	list_sort(NULL, &reserve_list, sram_reserve_cmp);
+
+	if (exports) {
+		sram->partition = devm_kcalloc(sram->dev,
+				       exports, sizeof(*sram->partition),
+				       GFP_KERNEL);
+		if (!sram->partition) {
+			ret = -ENOMEM;
+			goto err_chunks;
+		}
+	}
+
+	cur_start = 0;
+	list_for_each_entry(block, &reserve_list, list) {
+		/* can only happen if sections overlap */
+		if (block->start < cur_start) {
+			dev_err(sram->dev,
+				"block at 0x%x starts after current offset 0x%lx\n",
+				block->start, cur_start);
+			ret = -EINVAL;
+			sram_free_partitions(sram);
+			goto err_chunks;
+		}
+
+		if ((block->export || block->pool || block->protect_exec) &&
+		    block->size) {
+			ret = sram_add_partition(sram, block,
+						 res->start + block->start);
+			if (ret) {
+				sram_free_partitions(sram);
+				goto err_chunks;
+			}
+		}
+
+		/* current start is in a reserved block, so continue after it */
+		if (block->start == cur_start) {
+			cur_start = block->start + block->size;
+			continue;
+		}
+
+		/*
+		 * allocate the space between the current starting
+		 * address and the following reserved block, or the
+		 * end of the region.
+		 */
+		cur_size = block->start - cur_start;
+
+		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;
+			}
+		}
+
+		/* next allocation after this reserved block */
+		cur_start = block->start + block->size;
+	}
+
+err_chunks:
+	of_node_put(child);
+	kfree(rblocks);
+
+	return ret;
+}
+
+static int atmel_securam_wait(void)
+{
+	struct regmap *regmap;
+	u32 val;
+
+	regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-secumod");
+	if (IS_ERR(regmap))
+		return -ENODEV;
+
+	return regmap_read_poll_timeout(regmap, AT91_SECUMOD_RAMRDY, val,
+					val & AT91_SECUMOD_RAMRDY_READY,
+					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_config },
+	{ .compatible = "nvidia,tegra186-sysram", .data = &tegra_sysram_config },
+	{ .compatible = "nvidia,tegra194-sysram", .data = &tegra_sysram_config },
+	{ .compatible = "nvidia,tegra234-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;
+
+	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);
+		}
+
+		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;
+	else
+		clk_prepare_enable(sram->clk);
+
+	ret = sram_reserve_regions(sram,
+			platform_get_resource(pdev, IORESOURCE_MEM, 0));
+	if (ret)
+		goto err_disable_clk;
+
+	platform_set_drvdata(pdev, sram);
+
+	if (config && config->init) {
+		ret = config->init();
+		if (ret)
+			goto err_free_partitions;
+	}
+
+	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;
+
+err_free_partitions:
+	sram_free_partitions(sram);
+err_disable_clk:
+	if (sram->clk)
+		clk_disable_unprepare(sram->clk);
+
+	return ret;
+}
+
+static int sram_remove(struct platform_device *pdev)
+{
+	struct sram_dev *sram = platform_get_drvdata(pdev);
+
+	sram_free_partitions(sram);
+
+	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)
+		clk_disable_unprepare(sram->clk);
+
+	return 0;
+}
+
+static struct platform_driver sram_driver = {
+	.driver = {
+		.name = "sram",
+		.of_match_table = sram_dt_ids,
+	},
+	.probe = sram_probe,
+	.remove = sram_remove,
+};
+
+static int __init sram_init(void)
+{
+	return platform_driver_register(&sram_driver);
+}
+
+postcore_initcall(sram_init);