linuxdebug/drivers/misc/sram.c

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2024-07-16 15:50:57 +02:00
// 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);