diff options
Diffstat (limited to 'arch/avr32')
| -rw-r--r-- | arch/avr32/kernel/entry-avr32b.S | 42 |
1 files changed, 32 insertions, 10 deletions
diff --git a/arch/avr32/kernel/entry-avr32b.S b/arch/avr32/kernel/entry-avr32b.S index 3cdd707..2b398ca 100644 --- a/arch/avr32/kernel/entry-avr32b.S +++ b/arch/avr32/kernel/entry-avr32b.S @@ -98,10 +98,6 @@ tlb_miss_common: mfsr r0, SYSREG_TLBEAR mfsr r1, SYSREG_PTBR - /* Is it the vmalloc space? */ - bld r0, 31 - brcs handle_vmalloc_miss - /* * First level lookup: The PGD contains virtual pointers to * the second-level page tables, but they may be NULL if not @@ -143,15 +139,13 @@ pgtbl_lookup: tlbmiss_restore rete -handle_vmalloc_miss: - /* Simply do the lookup in init's page table */ - mov r1, lo(swapper_pg_dir) - orh r1, hi(swapper_pg_dir) - rjmp pgtbl_lookup - /* The slow path of the TLB miss handler */ .align 2 page_table_not_present: + /* Do we need to synchronize with swapper_pg_dir? */ + bld r0, 31 + brcs sync_with_swapper_pg_dir + page_not_present: tlbmiss_restore sub sp, 4 @@ -162,6 +156,34 @@ page_not_present: rcall do_page_fault rjmp ret_from_exception + .align 2 +sync_with_swapper_pg_dir: + /* + * If swapper_pg_dir contains a non-NULL second-level page + * table pointer, copy it into the current PGD. If not, we + * must handle it as a full-blown page fault. + * + * Jumping back to pgtbl_lookup causes an unnecessary lookup, + * but it is guaranteed to be a cache hit, it won't happen + * very often, and we absolutely do not want to sacrifice any + * performance in the fast path in order to improve this. + */ + mov r1, lo(swapper_pg_dir) + orh r1, hi(swapper_pg_dir) + ld.w r3, r1[r2 << 2] + cp.w r3, 0 + breq page_not_present + mfsr r1, SYSREG_PTBR + st.w r1[r2 << 2], r3 + rjmp pgtbl_lookup + + /* + * We currently have two bytes left at this point until we + * crash into the system call handler... + * + * Don't worry, the assembler will let us know. + */ + /* --- System Call --- */ |
