On Fri, Jan 14, 2011 at 04:21:10PM +0100, jean.pihet@xxxxxxxxxxxxxx wrote: > From: Jean Pihet <j-pihet@xxxxxx> > > The new fncpy API is better suited for copying some > code to SRAM at runtime. This patch changes the ad-hoc > code to the more generic fncpy API. > > Tested OK on OMAP3 in low power modes (RET/OFF) > with !CONFIG_THUMB2_KERNEL > > Signed-off-by: Jean Pihet <j-pihet@xxxxxx> > --- > arch/arm/plat-omap/sram.c | 7 +++---- > 1 files changed, 3 insertions(+), 4 deletions(-) > > diff --git a/arch/arm/plat-omap/sram.c b/arch/arm/plat-omap/sram.c > index e26e504..e2982b0 100644 > --- a/arch/arm/plat-omap/sram.c > +++ b/arch/arm/plat-omap/sram.c > @@ -23,7 +23,7 @@ > > #include <asm/tlb.h> > #include <asm/cacheflush.h> > - > +#include <asm/fncpy.h> > #include <asm/mach/map.h> > > #include <plat/sram.h> > @@ -251,9 +251,8 @@ void * omap_sram_push(void * start, unsigned long size) > > omap_sram_ceil -= size; > omap_sram_ceil = ROUND_DOWN(omap_sram_ceil, sizeof(void *)); > - memcpy((void *)omap_sram_ceil, start, size); > - flush_icache_range((unsigned long)omap_sram_ceil, > - (unsigned long)(omap_sram_ceil + size)); > + > + fncpy((void *)omap_sram_ceil, start, size); > > return (void *)omap_sram_ceil; That's actually wrong usage, as you won't get the T bit set if the original function had it. The right solution to this is to change omap_sram_push() to become just an allocator, and then use fncpy() outside of that. So: extern int my_func_size; extern void my_func(int blah); void (*sram_my_func)(int); void *sram = omap_sram_push(my_func_size); if (sram) sram_my_func = fncpy(sram, my_func, my_func_size); Two benefits: 1. you get the thumb mode bit propagated (which is the point of fncpy), and 2. you get the security of type safety between my_func and the sram function pointer. If you cast things to a void pointer and ignore the return value of fncpy then you lose the whole point of this API _and_ any form of type safety. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
