On Wed, Mar 25, 2020 at 11:33 PM John Rippetoe
<jrippe...@roboticresearch.com> wrote:
>
>
> >> 1. For each chip, files that include mpu support need to add a
> >> conditional to two included files
> >>
> >> #ifdef CONFIG_ARM_MPU
> >> # include "mpu.h"
> >> # include "<chip>_mpuinit.h"
> >> #endif
> >
> > Wouldn't it make more sense to put #ifdef CONFIG_ARM_MPU inside of
> > mpu.h and <chip>_mpuinit.h. That way, the problem is fixed in one
> > place for all time.
> >
> I hadn't considered that, but that does make more sense.
>
>
> > Another option would be to remove the inline qualifier and move the
> > functions into a .c file.
> >
> I'm equally fine with this, but I can see the appeal for wanting to keep
> the small functions inlined. Of the 12 funcitons in mpu.h, 9 are just
> wrappers around a call to mpu_configure_region that look like
>
>
> static inline void mpu_priv_intsram(uintptr_t base, size_t size)
> {
> /* The configure the region */
>
> mpu_configure_region(base, size,
> MPU_RASR_TEX_SO | /* Ordered */
> MPU_RASR_C | /* Cacheable */
> /* Not Bufferable */
> MPU_RASR_S | /* Shareable */
> MPU_RASR_AP_RWNO /* P:RW U:None */
> /* Instruction access */);
> }
>
>
> Like others have said, there is no guarantee these will be inlined.
> Furthermore, the build system doesn't currently enforce a minimum C99
> standard to ensure the inline keyword is even available. So I am in
> favor of moving the functions to a .c file in the name of clarity.
> Consolidating them into up_mpu.c seems like a good choice. If the
> overhead of an additional function call is problematic, we could
> predefine the flags and call mpu_configure_region() directly
>
> #define MPU_PRIV_INTSRAM MPU_RASR_TEX_SO | /* Ordered */
> MPU_RASR_C | /* Cacheable */
> /* Not Bufferable */
> MPU_RASR_S | /* Shareable */
> MPU_RASR_AP_RWNO /* P:RW U:None */
> /* Instruction access */);
>
>
> mpu_configure_region(base, size, MPU_PRIV_INTSRAM);
>
>
Or change mpu_priv_intsram to macro?
> John
>
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