From mboxrd@z Thu Jan 1 00:00:00 1970 From: tony@atomide.com (Tony Lindgren) Date: Wed, 4 Sep 2013 11:06:39 -0700 Subject: [RFC 3/4] Misc: SRAM: Hack for allowing executable code in SRAM. In-Reply-To: <1378226665-27090-4-git-send-email-Russ.Dill@ti.com> References: <1378226665-27090-1-git-send-email-Russ.Dill@ti.com> <1378226665-27090-4-git-send-email-Russ.Dill@ti.com> Message-ID: <20130904180638.GC31541@atomide.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org * Russ Dill [130903 09:52]: > The generic SRAM mechanism does not ioremap memory in a > manner that allows code to be executed from SRAM. There is > currently no generic way to request ioremap to return a > memory area with execution allowed. > > Insert a temporary hack for proof of concept on ARM. > > Signed-off-by: Russ Dill > --- > drivers/misc/sram.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c > index 08baaab..e059a23 100644 > --- a/drivers/misc/sram.c > +++ b/drivers/misc/sram.c > @@ -31,6 +31,7 @@ > #include > #include > #include > +#include > > #define SRAM_GRANULARITY 32 > > @@ -138,7 +139,7 @@ static int sram_probe(struct platform_device *pdev) > int ret; > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > - virt_base = devm_ioremap_resource(&pdev->dev, res); > + virt_base = __arm_ioremap_exec(res->start, resource_size(res), false); > if (IS_ERR(virt_base)) > return PTR_ERR(virt_base); You can get rid of this hack by defining ioremap_exec in include/asm-generic/io.h the same way as ioremap_nocache is done: #ifndef ioremap_exec #define ioremap_exec ioremap #endif Then the arch that need ioremap_exec can define and implement it. Needs to be reviewed on LKML naturally :) Regards, Tony