diff options
| -rw-r--r-- | drivers/misc/sram.c | 125 |
1 files changed, 118 insertions, 7 deletions
diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c index e3e421d..21181fa 100644 --- a/drivers/misc/sram.c +++ b/drivers/misc/sram.c @@ -24,6 +24,9 @@ #include <linux/err.h> #include <linux/io.h> #include <linux/of.h> +#include <linux/of_address.h> +#include <linux/list.h> +#include <linux/list_sort.h> #include <linux/platform_device.h> #include <linux/slab.h> #include <linux/spinlock.h> @@ -36,14 +39,35 @@ struct sram_dev { struct clk *clk; }; +struct sram_reserve { + struct list_head list; + u32 start; + u32 size; +}; + +static int sram_reserve_cmp(void *priv, struct list_head *a, + 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_probe(struct platform_device *pdev) { void __iomem *virt_base; struct sram_dev *sram; struct resource *res; - unsigned long size; + struct device_node *np = pdev->dev.of_node, *child; + unsigned long size, cur_start, cur_size; + struct sram_reserve *rblocks, *block; + struct list_head reserve_list; + unsigned int nblocks; int ret; + INIT_LIST_HEAD(&reserve_list); + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); virt_base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(virt_base)) @@ -65,19 +89,106 @@ static int sram_probe(struct platform_device *pdev) if (!sram->pool) return -ENOMEM; - ret = gen_pool_add_virt(sram->pool, (unsigned long)virt_base, - res->start, size, -1); - if (ret < 0) { - if (sram->clk) - clk_disable_unprepare(sram->clk); - return ret; + /* + * 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 = kmalloc((nblocks) * sizeof(*rblocks), GFP_KERNEL); + if (!rblocks) { + ret = -ENOMEM; + goto err_alloc; } + 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(&pdev->dev, + "could not get address for node %s\n", + child->full_name); + goto err_chunks; + } + + if (child_res.start < res->start || child_res.end > res->end) { + dev_err(&pdev->dev, + "reserved block %s outside the sram area\n", + child->full_name); + 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); + + dev_dbg(&pdev->dev, "found reserved block 0x%x-0x%x\n", + block->start, + block->start + block->size); + + block++; + } + + /* 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); + + cur_start = 0; + + list_for_each_entry(block, &reserve_list, list) { + /* can only happen if sections overlap */ + if (block->start < cur_start) { + dev_err(&pdev->dev, + "block at 0x%x starts after current offset 0x%lx\n", + block->start, cur_start); + ret = -EINVAL; + 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(&pdev->dev, "adding chunk 0x%lx-0x%lx\n", + cur_start, cur_start + cur_size); + ret = gen_pool_add_virt(sram->pool, + (unsigned long)virt_base + cur_start, + res->start + cur_start, cur_size, -1); + if (ret < 0) + goto err_chunks; + + /* next allocation after this reserved block */ + cur_start = block->start + block->size; + } + + kfree(rblocks); + platform_set_drvdata(pdev, sram); dev_dbg(&pdev->dev, "SRAM pool: %ld KiB @ 0x%p\n", size / 1024, virt_base); return 0; + +err_chunks: + kfree(rblocks); +err_alloc: + if (sram->clk) + clk_disable_unprepare(sram->clk); + return ret; } static int sram_remove(struct platform_device *pdev) |
