This implements support for the mmio-sram-reserved option to keep the genpool from using these areas.
Suggested-by: Rob Herring <[email protected]> Signed-off-by: Heiko Stuebner <[email protected]> Tested-by: Ulrich Prinz <[email protected]> --- drivers/misc/sram.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 113 insertions(+), 8 deletions(-) diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c index afe66571..8681961 100644 --- a/drivers/misc/sram.c +++ b/drivers/misc/sram.c @@ -36,13 +36,23 @@ struct sram_dev { struct clk *clk; }; +struct sram_reserve { + u32 start; + u32 size; +}; + static int sram_probe(struct platform_device *pdev) { void __iomem *virt_base; struct sram_dev *sram; struct resource *res; - unsigned long size; - int ret; + struct device_node *np = pdev->dev.of_node; + unsigned long size, cur_start, cur_size; + int reserved_size = 0; + struct sram_reserve *rblocks; + unsigned int nblocks; + int ret = 0; + int i; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); virt_base = devm_ioremap_resource(&pdev->dev, res); @@ -65,19 +75,114 @@ 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; + if (np) { + reserved_size = of_property_count_u32_elems(np, + "mmio-sram-reserved"); + + /* mmio-sram-reserved is optional, so its absence is no error */ + if (reserved_size < 0) + reserved_size = 0; + + if (reserved_size % 2) { + dev_warn(&pdev->dev, "wrong number of arguments in mmio-sram-reserved\n"); + reserved_size = 0; + } + } + + /* + * We need an additional block to mark the end of the memory region + * after the reserved blocks from the dt are processed. + */ + nblocks = reserved_size / 2 + 1; + rblocks = kmalloc((nblocks) * sizeof(*rblocks), GFP_KERNEL); + if (!rblocks) { + ret = -ENOMEM; + goto err_alloc; + } + + cur_start = 0; + for (i = 0; i < nblocks - 1; i++) { + /* checked the property exists above so can skip return vals */ + of_property_read_u32_index(np, "mmio-sram-reserved", + 2 * i, &rblocks[i].start); + of_property_read_u32_index(np, "mmio-sram-reserved", + 2 * i + 1, &rblocks[i].size); + + if (rblocks[i].start < cur_start) { + dev_err(&pdev->dev, + "unsorted reserved list (0x%x before current 0x%lx)\n", + rblocks[i].start, cur_start); + ret = -EINVAL; + goto err_chunks; + } + + if (rblocks[i].start >= size) { + dev_err(&pdev->dev, + "reserved block at 0x%x outside the sram size 0x%lx\n", + rblocks[i].start, size); + ret = -EINVAL; + goto err_chunks; + } + + if (rblocks[i].start + rblocks[i].size > size) { + dev_warn(&pdev->dev, + "reserved block at 0x%x to large, trimming\n", + rblocks[i].start); + rblocks[i].size = size - rblocks[i].start; + } + + cur_start = rblocks[i].start + rblocks[i].size; + + dev_dbg(&pdev->dev, "found reserved block 0x%x-0x%x\n", + rblocks[i].start, + rblocks[i].start + rblocks[i].size); + } + + /* the last chunk marks the end of the region */ + rblocks[nblocks - 1].start = size; + rblocks[nblocks - 1].size = 0; + + cur_start = 0; + for (i = 0; i < nblocks; i++) { + /* current start is in a reserved block, so continue after it */ + if (rblocks[i].start == cur_start) { + cur_start = rblocks[i].start + rblocks[i].size; + continue; + } + + /* + * allocate the space between the current starting + * address and the following reserved block, or the + * end of the region. + */ + cur_size = rblocks[i].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 = rblocks[i].start + rblocks[i].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) -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
