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| author | Ben Dooks <ben.dooks@codethink.co.uk> | 2013-02-09 23:07:10 +0000 |
|---|---|---|
| committer | Ben Dooks <ben.dooks@codethink.co.uk> | 2013-02-10 15:01:26 +0000 |
| commit | 26456db1480f2ce09e96478d617617be6ca1b2df (patch) | |
| tree | 5b0534c6246f46a43910f9aa5570a3196c54bd9e | |
| parent | fae3757e70e888c5f43a75b22d5d8e46b2b60f84 (diff) | |
| download | linux-baserock/bjdooks/be-asid-fix.tar.gz | |
ARM: mm: mm->context.id fix for big-endianbaserock/bjdooks/be-asid-fix
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.
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
| -rw-r--r-- | arch/arm/mm/context.c | 3 | ||||
| -rw-r--r-- | arch/arm/mm/proc-macros.S | 5 |
2 files changed, 8 insertions, 0 deletions
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 /* |