| // 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); |
| 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); |
| 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; |
| |
| 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 of_device_id sram_dt_ids[] = { |
| { .compatible = "mmio-sram" }, |
| { .compatible = "atmel,sama5d2-securam", .data = atmel_securam_wait }, |
| {} |
| }; |
| |
| static int sram_probe(struct platform_device *pdev) |
| { |
| struct sram_dev *sram; |
| int ret; |
| int (*init_func)(void); |
| |
| sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL); |
| if (!sram) |
| return -ENOMEM; |
| |
| sram->dev = &pdev->dev; |
| |
| if (of_property_read_bool(pdev->dev.of_node, "no-memory-wc")) |
| sram->virt_base = devm_platform_ioremap_resource(pdev, 0); |
| else |
| sram->virt_base = devm_platform_ioremap_resource_wc(pdev, 0); |
| 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); |
| |
| init_func = of_device_get_match_data(&pdev->dev); |
| if (init_func) { |
| ret = init_func(); |
| 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); |
| |
| 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 (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); |