From: Ben Dooks Date: Mon, 11 Feb 2013 11:25:06 +0000 (+0100) Subject: ARM: 7649/1: mm: mm->context.id fix for big-endian X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=9520a5bece13b7382f4b0059180f61530c423c81;p=linux-beck.git ARM: 7649/1: mm: mm->context.id fix for big-endian Since the new ASID code in b5466f8728527a05a493cc4abe9e6f034a1bbaab ("ARM: mm: remove IPI broadcasting on ASID rollover") was changed to use 64bit operations it has broken the BE operation due to an issue with the MM code accessing sub-fields of mm->context.id. When running in BE mode we see the values in mm->context.id are stored with the highest value first, so the LDR in the arch/arm/mm/proc-macros.S reads the wrong part of this field. To resolve this, change the LDR in the mmid macro to load from +4. Acked-by: Will Deacon Signed-off-by: Ben Dooks Signed-off-by: Russell King --- diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c index bc4a5e9ebb78..7a0511191f6b 100644 --- a/arch/arm/mm/context.c +++ b/arch/arm/mm/context.c @@ -34,6 +34,9 @@ * The ASID is used to tag entries in the CPU caches and TLBs. * The context ID is used by debuggers and trace logic, and * should be unique within all running processes. + * + * In big endian operation, the two 32 bit words are swapped if accesed by + * non 64-bit operations. */ #define ASID_FIRST_VERSION (1ULL << ASID_BITS) #define NUM_USER_ASIDS (ASID_FIRST_VERSION - 1) diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S index eb6aa73bc8b7..f9a0aa725ea9 100644 --- a/arch/arm/mm/proc-macros.S +++ b/arch/arm/mm/proc-macros.S @@ -38,9 +38,14 @@ /* * mmid - get context id from mm pointer (mm->context.id) + * note, this field is 64bit, so in big-endian the two words are swapped too. */ .macro mmid, rd, rn +#ifdef __ARMEB__ + ldr \rd, [\rn, #MM_CONTEXT_ID + 4 ] +#else ldr \rd, [\rn, #MM_CONTEXT_ID] +#endif .endm /*