Hi, There are several instances when one would want to execute out of on-chip SRAM, such as PM code on ARM platforms, so once again revisiting this series to allow that. Seems that having a solution for allowing SRAM to be mapped as executable will help clean up PM code on several ARM platforms and also open the door for others like TI AM335x and AM437x. This was first sent here [1] but this is rebased and updated for v4.6-rc. Many platforms have migrated to using the generic SRAM driver at drivers/misc/sram.c but it doesn't seem like there is a clean solution for the common problem of needing to map executable pages. Currently I see several platforms (at-91, imx6, socfpga) taking the address allocated by the genpool given by the SRAM driver and then calling __arm_ioremap_exec on it again to get a new address that can be executed. This doesn't seem like the cleanest solution, but maybe it works for code that is under mach-xxx but what about code that migrates outside into the drivers layer? Do any other architectures have a requirement for this? I've converted omap3 PM code to use the generic SRAM driver which I'll send in a series right after this one, and AM335x and AM437x can both make use of this series as well and even go as far as to move a chunk of the PM code into drivers (needs to be updated but sent long ago here [2]), but that will be blocked if we don't have a generic way to ioremap memory as exec, or at least a way to do it from drivers/. If we don't want to go down this path, is there a better idea for how to call ioremap_exec from drivers/ that we can all agree on? Regards, Dave [1] https://lkml.org/lkml/2014/11/26/575 [2] http://lists.infradead.org/pipermail/linux-arm-kernel/2014-November/306534.html Dave Gerlach (1): misc: SRAM: Add option to map SRAM to allow code execution Russ Dill (2): asm-generic: io: Add exec versions of ioremap lib: devres: Add exec and exec_nocache versions of devm_ioremap Documentation/devicetree/bindings/sram/sram.txt | 2 + arch/arm/include/asm/io.h | 5 +++ arch/arm/mm/ioremap.c | 14 ++++++ arch/arm/mm/nommu.c | 14 ++++++ drivers/misc/sram.c | 8 ++++ include/asm-generic/iomap.h | 5 +++ include/linux/io.h | 5 +++ lib/devres.c | 58 +++++++++++++++++++++++++ 8 files changed, 111 insertions(+) -- 2.7.3 -- 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
