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    SubjectRe: [PATCH] ARM: mmp: map sram as MT_MEMORY rather than MT_DEVICE
    On Tue, Aug 23, 2011 at 7:47 AM, Andres Salomon <dilinger@queued.net> wrote:
    > The sram code allocates memory with ioremap, which assumes MT_DEVICE
    > for memory protections.  This explodes when we map sram for power
    > management purposes and then attempt to execute it (jump_to_lp_sram)
    > on the OLPC XO-1.75.  Instead, we want to specify MT_MEMORY, which
    > doesn't set the L_PTE_XN bit.
    >
    > Signed-off-by: Andres Salomon <dilinger@queued.net>
    > ---
    >  arch/arm/mach-mmp/sram.c |    4 +++-
    >  1 files changed, 3 insertions(+), 1 deletions(-)
    >
    > Eric, this patch is against the devel branch of your pxa tree.
    >
    > diff --git a/arch/arm/mach-mmp/sram.c b/arch/arm/mach-mmp/sram.c
    > index 4304f95..ca4d3c1 100644
    > --- a/arch/arm/mach-mmp/sram.c
    > +++ b/arch/arm/mach-mmp/sram.c
    > @@ -21,6 +21,7 @@
    >  #include <linux/err.h>
    >  #include <linux/slab.h>
    >  #include <linux/genalloc.h>
    > +#include <asm/mach/map.h>
    >
    >  #include <mach/sram.h>
    >
    > @@ -87,7 +88,8 @@ static int __devinit sram_probe(struct platform_device *pdev)
    >
    >        info->sram_phys   = (phys_addr_t)res->start;
    >        info->sram_size   = resource_size(res);
    > -       info->sram_virt   = ioremap(info->sram_phys, info->sram_size);
    > +       info->sram_virt   = __arm_ioremap(info->sram_phys, info->sram_size,
    > +                                         MT_MEMORY);

    I doubt MT_MEMORY is intended for use with __arm_ioremap(). There could
    be other way around to the L_PTE_XN bit.

    One other way I'm actually thinking of is to add the SRAM mapping to
    mmp_map_io(). The difference of SRAM offset/size may result the
    separation of mmp_map_io() into {pxa168,pxa910,mmp2}_map_io()
    if necessary.

    >        info->pool_name   = kstrdup(pdata->pool_name, GFP_KERNEL);
    >        info->granularity = pdata->granularity;
    >
    > --
    > 1.7.2.5
    >
    >
    --
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