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![Vladimir Zapolskiy](/assets/img/avatar_default.png)
Both devm_ioremap() and devm_ioremap_wc() functions return either
a pointer to valid iomem region or NULL, check for IS_ERR() is improper
and may result in oops on error path. Now on error -ENOMEM is returned.
Fixes: 0ab163ad1e
("misc: sram: switch to ioremap_wc from ioremap")
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
429 lines
10 KiB
C
429 lines
10 KiB
C
/*
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* Generic on-chip SRAM allocation driver
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*
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* Copyright (C) 2012 Philipp Zabel, Pengutronix
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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* MA 02110-1301, USA.
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*/
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#include <linux/clk.h>
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#include <linux/genalloc.h>
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#include <linux/io.h>
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#include <linux/list_sort.h>
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#include <linux/of_address.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#define SRAM_GRANULARITY 32
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struct sram_partition {
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void __iomem *base;
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struct gen_pool *pool;
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struct bin_attribute battr;
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struct mutex lock;
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};
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struct sram_dev {
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struct device *dev;
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void __iomem *virt_base;
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struct gen_pool *pool;
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struct clk *clk;
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struct sram_partition *partition;
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u32 partitions;
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};
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struct sram_reserve {
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struct list_head list;
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u32 start;
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u32 size;
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bool export;
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bool pool;
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const char *label;
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};
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static ssize_t sram_read(struct file *filp, struct kobject *kobj,
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struct bin_attribute *attr,
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char *buf, loff_t pos, size_t count)
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{
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struct sram_partition *part;
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part = container_of(attr, struct sram_partition, battr);
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mutex_lock(&part->lock);
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memcpy_fromio(buf, part->base + pos, count);
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mutex_unlock(&part->lock);
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return count;
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}
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static ssize_t sram_write(struct file *filp, struct kobject *kobj,
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struct bin_attribute *attr,
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char *buf, loff_t pos, size_t count)
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{
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struct sram_partition *part;
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part = container_of(attr, struct sram_partition, battr);
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mutex_lock(&part->lock);
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memcpy_toio(part->base + pos, buf, count);
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mutex_unlock(&part->lock);
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return count;
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}
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static int sram_add_pool(struct sram_dev *sram, struct sram_reserve *block,
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phys_addr_t start, struct sram_partition *part)
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{
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int ret;
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part->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY),
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NUMA_NO_NODE, block->label);
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if (IS_ERR(part->pool))
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return PTR_ERR(part->pool);
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ret = gen_pool_add_virt(part->pool, (unsigned long)part->base, start,
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block->size, NUMA_NO_NODE);
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if (ret < 0) {
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dev_err(sram->dev, "failed to register subpool: %d\n", ret);
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return ret;
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}
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return 0;
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}
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static int sram_add_export(struct sram_dev *sram, struct sram_reserve *block,
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phys_addr_t start, struct sram_partition *part)
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{
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sysfs_bin_attr_init(&part->battr);
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part->battr.attr.name = devm_kasprintf(sram->dev, GFP_KERNEL,
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"%llx.sram",
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(unsigned long long)start);
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if (!part->battr.attr.name)
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return -ENOMEM;
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part->battr.attr.mode = S_IRUSR | S_IWUSR;
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part->battr.read = sram_read;
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part->battr.write = sram_write;
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part->battr.size = block->size;
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return device_create_bin_file(sram->dev, &part->battr);
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}
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static int sram_add_partition(struct sram_dev *sram, struct sram_reserve *block,
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phys_addr_t start)
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{
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int ret;
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struct sram_partition *part = &sram->partition[sram->partitions];
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mutex_init(&part->lock);
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part->base = sram->virt_base + block->start;
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if (block->pool) {
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ret = sram_add_pool(sram, block, start, part);
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if (ret)
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return ret;
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}
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if (block->export) {
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ret = sram_add_export(sram, block, start, part);
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if (ret)
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return ret;
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}
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sram->partitions++;
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return 0;
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}
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static void sram_free_partitions(struct sram_dev *sram)
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{
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struct sram_partition *part;
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if (!sram->partitions)
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return;
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part = &sram->partition[sram->partitions - 1];
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for (; sram->partitions; sram->partitions--, part--) {
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if (part->battr.size)
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device_remove_bin_file(sram->dev, &part->battr);
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if (part->pool &&
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gen_pool_avail(part->pool) < gen_pool_size(part->pool))
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dev_err(sram->dev, "removed pool while SRAM allocated\n");
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}
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}
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static int sram_reserve_cmp(void *priv, struct list_head *a,
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struct list_head *b)
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{
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struct sram_reserve *ra = list_entry(a, struct sram_reserve, list);
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struct sram_reserve *rb = list_entry(b, struct sram_reserve, list);
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return ra->start - rb->start;
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}
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static int sram_reserve_regions(struct sram_dev *sram, struct resource *res)
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{
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struct device_node *np = sram->dev->of_node, *child;
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unsigned long size, cur_start, cur_size;
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struct sram_reserve *rblocks, *block;
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struct list_head reserve_list;
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unsigned int nblocks, exports = 0;
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const char *label;
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int ret = 0;
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INIT_LIST_HEAD(&reserve_list);
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size = resource_size(res);
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/*
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* We need an additional block to mark the end of the memory region
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* after the reserved blocks from the dt are processed.
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*/
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nblocks = (np) ? of_get_available_child_count(np) + 1 : 1;
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rblocks = kzalloc((nblocks) * sizeof(*rblocks), GFP_KERNEL);
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if (!rblocks)
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return -ENOMEM;
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block = &rblocks[0];
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for_each_available_child_of_node(np, child) {
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struct resource child_res;
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ret = of_address_to_resource(child, 0, &child_res);
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if (ret < 0) {
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dev_err(sram->dev,
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"could not get address for node %s\n",
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child->full_name);
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goto err_chunks;
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}
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if (child_res.start < res->start || child_res.end > res->end) {
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dev_err(sram->dev,
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"reserved block %s outside the sram area\n",
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child->full_name);
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ret = -EINVAL;
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goto err_chunks;
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}
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block->start = child_res.start - res->start;
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block->size = resource_size(&child_res);
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list_add_tail(&block->list, &reserve_list);
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if (of_find_property(child, "export", NULL))
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block->export = true;
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if (of_find_property(child, "pool", NULL))
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block->pool = true;
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if ((block->export || block->pool) && block->size) {
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exports++;
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label = NULL;
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ret = of_property_read_string(child, "label", &label);
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if (ret && ret != -EINVAL) {
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dev_err(sram->dev,
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"%s has invalid label name\n",
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child->full_name);
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goto err_chunks;
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}
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if (!label)
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label = child->name;
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block->label = devm_kstrdup(sram->dev,
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label, GFP_KERNEL);
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if (!block->label)
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goto err_chunks;
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dev_dbg(sram->dev, "found %sblock '%s' 0x%x-0x%x\n",
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block->export ? "exported " : "", block->label,
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block->start, block->start + block->size);
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} else {
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dev_dbg(sram->dev, "found reserved block 0x%x-0x%x\n",
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block->start, block->start + block->size);
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}
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block++;
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}
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child = NULL;
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/* the last chunk marks the end of the region */
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rblocks[nblocks - 1].start = size;
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rblocks[nblocks - 1].size = 0;
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list_add_tail(&rblocks[nblocks - 1].list, &reserve_list);
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list_sort(NULL, &reserve_list, sram_reserve_cmp);
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if (exports) {
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sram->partition = devm_kzalloc(sram->dev,
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exports * sizeof(*sram->partition),
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GFP_KERNEL);
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if (!sram->partition) {
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ret = -ENOMEM;
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goto err_chunks;
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}
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}
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cur_start = 0;
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list_for_each_entry(block, &reserve_list, list) {
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/* can only happen if sections overlap */
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if (block->start < cur_start) {
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dev_err(sram->dev,
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"block at 0x%x starts after current offset 0x%lx\n",
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block->start, cur_start);
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ret = -EINVAL;
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sram_free_partitions(sram);
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goto err_chunks;
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}
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if ((block->export || block->pool) && block->size) {
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ret = sram_add_partition(sram, block,
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res->start + block->start);
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if (ret) {
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sram_free_partitions(sram);
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goto err_chunks;
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}
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}
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/* current start is in a reserved block, so continue after it */
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if (block->start == cur_start) {
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cur_start = block->start + block->size;
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continue;
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}
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/*
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* allocate the space between the current starting
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* address and the following reserved block, or the
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* end of the region.
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*/
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cur_size = block->start - cur_start;
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dev_dbg(sram->dev, "adding chunk 0x%lx-0x%lx\n",
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cur_start, cur_start + cur_size);
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ret = gen_pool_add_virt(sram->pool,
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(unsigned long)sram->virt_base + cur_start,
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res->start + cur_start, cur_size, -1);
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if (ret < 0) {
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sram_free_partitions(sram);
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goto err_chunks;
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}
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/* next allocation after this reserved block */
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cur_start = block->start + block->size;
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}
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err_chunks:
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if (child)
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of_node_put(child);
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kfree(rblocks);
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return ret;
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}
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static int sram_probe(struct platform_device *pdev)
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{
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struct sram_dev *sram;
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struct resource *res;
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size_t size;
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int ret;
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sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
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if (!sram)
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return -ENOMEM;
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sram->dev = &pdev->dev;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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dev_err(sram->dev, "found no memory resource\n");
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return -EINVAL;
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}
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size = resource_size(res);
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if (!devm_request_mem_region(sram->dev, res->start, size, pdev->name)) {
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dev_err(sram->dev, "could not request region for resource\n");
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return -EBUSY;
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}
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if (of_property_read_bool(pdev->dev.of_node, "no-memory-wc"))
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sram->virt_base = devm_ioremap(sram->dev, res->start, size);
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else
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sram->virt_base = devm_ioremap_wc(sram->dev, res->start, size);
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if (!sram->virt_base)
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return -ENOMEM;
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sram->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY),
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NUMA_NO_NODE, NULL);
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if (IS_ERR(sram->pool))
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return PTR_ERR(sram->pool);
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ret = sram_reserve_regions(sram, res);
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if (ret)
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return ret;
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sram->clk = devm_clk_get(sram->dev, NULL);
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if (IS_ERR(sram->clk))
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sram->clk = NULL;
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else
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clk_prepare_enable(sram->clk);
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platform_set_drvdata(pdev, sram);
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dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n",
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gen_pool_size(sram->pool) / 1024, sram->virt_base);
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return 0;
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}
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static int sram_remove(struct platform_device *pdev)
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{
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struct sram_dev *sram = platform_get_drvdata(pdev);
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sram_free_partitions(sram);
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if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool))
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dev_err(sram->dev, "removed while SRAM allocated\n");
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if (sram->clk)
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clk_disable_unprepare(sram->clk);
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return 0;
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}
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#ifdef CONFIG_OF
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static const struct of_device_id sram_dt_ids[] = {
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{ .compatible = "mmio-sram" },
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{}
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};
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#endif
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static struct platform_driver sram_driver = {
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.driver = {
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.name = "sram",
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.of_match_table = of_match_ptr(sram_dt_ids),
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},
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.probe = sram_probe,
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.remove = sram_remove,
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};
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static int __init sram_init(void)
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{
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return platform_driver_register(&sram_driver);
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}
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postcore_initcall(sram_init);
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