On 6 March 2014 20:42, Stephen Boyd sboyd@codeaurora.org wrote:
On 03/05, Sebastian Capella wrote:
diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index 8756e4b..d32adbb 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -291,6 +291,7 @@ static inline void *phys_to_virt(phys_addr_t x) */ #define __pa(x) __virt_to_phys((unsigned long)(x)) #define __va(x) ((void *)__phys_to_virt((phys_addr_t)(x))) +#define __pa_symbol(x) __pa((unsigned long)(x))
Looking at this definition now it doesn't look right. Isn't &__nosave_begin a virtual address? Casting it to an unsigned long isn't going to give you a physical address. Why can't we use __pa()?
You're correct, sorry, I missed removing the cast, it's not needed. I've removed the __pa_symbol define as I'm switching to the __pa implementation you suggested below.
+extern const void __nosave_begin, __nosave_end;
+int pfn_is_nosave(unsigned long pfn) +{
unsigned long nosave_begin_pfn =__pa_symbol(&__nosave_begin) >> PAGE_SHIFT;unsigned long nosave_end_pfn =PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT;return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);+}
Perhaps this code could be:
unsigned long nosave_begin_pfn = virt_to_pfn(&__nosave_begin); unsigned long nosave_end_pfn = virt_to_pfn(&__nosave_end); return (pfn >= nosave_begin_pfn) && (pfn <= nosave_end_pfn);or if virt_to_pfn() doesn't exist on ARM and we can't add it for some reason:
unsigned long nosave_begin_pfn = __phys_to_pfn(__pa(&__nosave_begin)); unsigned long nosave_end_pfn = __phys_to_pfn(__pa(&__nosave_end)); return (pfn >= nosave_begin_pfn) && (pfn <= nosave_end_pfn);
I've moved to this second implementation. I don't think I understand the ramifications enough to add the virt_to_pfn call for arm.
I've changed one thing. __nosave_end is pointing at the first byte not included in the nosave region. I subtracted one from it so that we make sure we're referring to the last pfn, and left the pfn comparison as you'd suggested.
int pfn_is_nosave(unsigned long pfn) { unsigned long nosave_begin_pfn = __phys_to_pfn(__pa(&__nosave_begin)); unsigned long nosave_end_pfn = __phys_to_pfn(__pa(&__nosave_end - 1));
return (pfn >= nosave_begin_pfn) && (pfn <= nosave_end_pfn); }
I'll test this and post it if everyone's ok with it.
Thanks for your review and comments Stephen!
Sebastian