linux/drivers/misc/sram.c
Uwe Kleine-König 74b32514f0 misc: sram: Convert to platform remove callback returning void
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/946ebc33a01bf700171257cd219fbe8626bc0c99.1708508896.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-05 14:28:52 +00:00

463 lines
11 KiB
C

// 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.h>
#include <linux/of_address.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);
block->export = of_property_read_bool(child, "export");
block->pool = of_property_read_bool(child, "pool");
block->protect_exec = of_property_read_bool(child, "protect-exec");
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)
block->label = devm_kasprintf(sram->dev, GFP_KERNEL,
"%s", of_node_full_name(child));
else
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;
struct clk *clk;
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);
}
clk = devm_clk_get_optional_enabled(sram->dev, NULL);
if (IS_ERR(clk))
return PTR_ERR(clk);
ret = sram_reserve_regions(sram,
platform_get_resource(pdev, IORESOURCE_MEM, 0));
if (ret)
return ret;
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);
return ret;
}
static void 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");
}
static struct platform_driver sram_driver = {
.driver = {
.name = "sram",
.of_match_table = sram_dt_ids,
},
.probe = sram_probe,
.remove_new = sram_remove,
};
static int __init sram_init(void)
{
return platform_driver_register(&sram_driver);
}
postcore_initcall(sram_init);