Hi Heiko, Am Dienstag, den 25.06.2013, 10:47 +0200 schrieb Heiko Stübner: > Some SoCs need parts of their sram for special purposes. So while being part > of the periphal, it should not be part of the genpool controlling the sram. > > Threfore add an option mmio-sram-reserved to keep arbitary portions of the > sram from being part of the pool. > > Suggested-by: Rob Herring <robherri...@gmail.com> > Signed-off-by: Heiko Stuebner <he...@sntech.de> > --- > Documentation/devicetree/bindings/misc/sram.txt | 8 +++ > drivers/misc/sram.c | 86 > +++++++++++++++++++++-- > 2 files changed, 88 insertions(+), 6 deletions(-) > > diff --git a/Documentation/devicetree/bindings/misc/sram.txt > b/Documentation/devicetree/bindings/misc/sram.txt > index 4d0a00e..eae080e 100644 > --- a/Documentation/devicetree/bindings/misc/sram.txt > +++ b/Documentation/devicetree/bindings/misc/sram.txt > @@ -8,9 +8,17 @@ Required properties: > > - reg : SRAM iomem address range > > +Optional properties: > + > +- mmio-sram-reserved: ordered list of reserved chunks inside the sram that > + should not become part of the genalloc pool. > + Format is <base size>, <base size>, ...; with base being relative to the > + reg property base. > +
the keyword to reserve blocks of ram is /memreserve/ - should this property name be aligned with that? > Example: > > sram: sram@5c000000 { > compatible = "mmio-sram"; > reg = <0x5c000000 0x40000>; /* 256 KiB SRAM at address 0x5c000000 */ > + mmio-sram-reserved = <0x0 0x100>; /* reserve 0x5c000000-0x5c000100 */ > }; > diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c > index afe66571..5fccbe3 100644 > --- a/drivers/misc/sram.c > +++ b/drivers/misc/sram.c > @@ -42,6 +42,8 @@ static int sram_probe(struct platform_device *pdev) > struct sram_dev *sram; > struct resource *res; > unsigned long size; > + const __be32 *reserved_list = NULL; > + int reserved_size = 0; > int ret; > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > @@ -65,12 +67,89 @@ 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 (pdev->dev.of_node) { > + reserved_list = of_get_property(pdev->dev.of_node, > + "mmio-sram-reserved", > + &reserved_size); > + if (reserved_list) { > + reserved_size /= sizeof(*reserved_list); > + if (!reserved_size || reserved_size % 2) { > + dev_warn(&pdev->dev, "wrong number of arguments > in mmio-sram-reserved\n"); > + reserved_list = NULL; > + } > + } > + } > + > + if (!reserved_list) { > + 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; > + } Moving the clk_prepare_enable() further down would allow to avoid the clk_disable_unprepare() in every error path, > + } else { > + unsigned int cur_start = 0; > + unsigned int cur_size; > + unsigned int rstart; > + unsigned int rsize; > + int i; > + > + for (i = 0; i < reserved_size; i += 2) { > + /* get the next reserved block */ > + rstart = be32_to_cpu(*reserved_list++); > + rsize = be32_to_cpu(*reserved_list++); > + > + /* catch unsorted list entries */ > + if (rstart < cur_start) { > + dev_err(&pdev->dev, "unsorted reserved list > (0x%x before current 0x%x)\n", > + rstart, cur_start); > + if (sram->clk) > + clk_disable_unprepare(sram->clk); like here > + return -EINVAL; > + } > + > + dev_dbg(&pdev->dev, "found reserved block 0x%x-0x%x\n", > + rstart, rstart + rsize); > + > + /* current start is in a reserved block */ > + if (rstart <= cur_start) { > + cur_start = rstart + rsize; > + continue; > + } > + > + /* > + * allocate the space between the current starting > + * address and the following reserved block > + */ > + cur_size = rstart - cur_start; > + > + dev_dbg(&pdev->dev, "adding chunk 0x%x-0x%x\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) { > + if (sram->clk) > + clk_disable_unprepare(sram->clk); and here. > + return ret; > + } > + > + /* next allocation after this reserved block */ > + cur_start = rstart + rsize; > + } > + > + /* allocate the space after the last reserved block */ > + if (cur_start < size) { > + cur_size = size - cur_start; > + > + dev_dbg(&pdev->dev, "adding chunk 0x%x-0x%x\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); > + } > + > } > > platform_set_drvdata(pdev, sram); Also, I think you could reduce the duplication of gen_pool_add_virt() function calls, somehow like this: unsigned int cur_start = 0; unsigned int cur_size; unsigned int rstart; unsigned int rsize; int i = 0; if (!reserved_list) reserved_size = 0; for (i = 0; i < (reserved_size + 2); i += 2) { if (i < reserved_size) { /* get the next reserved block */ rstart = be32_to_cpu(*reserved_list++); rsize = be32_to_cpu(*reserved_list++); /* catch unsorted list entries */ if (rstart < cur_start) { dev_err(&pdev->dev, "unsorted reserved list (0x%x before current 0x%x)\n", rstart, cur_start); return -EINVAL; } dev_dbg(&pdev->dev, "found reserved block 0x%x-0x%x\n", rstart, rstart + rsize); } else { /* the last chunk extends to the end of the region */ rstart = size; } /* current start is in a reserved block */ if (rstart <= cur_start) { cur_start = rstart + rsize; continue; } /* * allocate the space between the current starting * address and the following reserved block, or the * end of the region. */ cur_size = rstart - cur_start; dev_dbg(&pdev->dev, "adding chunk 0x%x-0x%x\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) return ret; } regards Philipp _______________________________________________ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss