sh: TLB fast path optimizations for load/store exceptions.
This only bothers with the TLB entry flush in the case of the initial
page write exception, as it is unecessary in the case of the load/store
exceptions.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/mm/fault_32.c b/arch/sh/mm/fault_32.c
index 4184064..f1c93c8 100644
--- a/arch/sh/mm/fault_32.c
+++ b/arch/sh/mm/fault_32.c
@@ -327,7 +327,6 @@
pmd_t *pmd;
pte_t *pte;
pte_t entry;
- int ret = 1;
/*
* We don't take page faults for P1, P2, and parts of P4, these
@@ -338,40 +337,41 @@
pgd = pgd_offset_k(address);
} else {
if (unlikely(address >= TASK_SIZE || !current->mm))
- goto out;
+ return 1;
pgd = pgd_offset(current->mm, address);
}
pud = pud_offset(pgd, address);
if (pud_none_or_clear_bad(pud))
- goto out;
+ return 1;
pmd = pmd_offset(pud, address);
if (pmd_none_or_clear_bad(pmd))
- goto out;
+ return 1;
pte = pte_offset_kernel(pmd, address);
entry = *pte;
if (unlikely(pte_none(entry) || pte_not_present(entry)))
- goto out;
+ return 1;
if (unlikely(writeaccess && !pte_write(entry)))
- goto out;
+ return 1;
if (writeaccess)
entry = pte_mkdirty(entry);
entry = pte_mkyoung(entry);
+ set_pte(pte, entry);
+
#if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SMP)
/*
- * ITLB is not affected by "ldtlb" instruction.
- * So, we need to flush the entry by ourselves.
+ * SH-4 does not set MMUCR.RC to the corresponding TLB entry in
+ * the case of an initial page write exception, so we need to
+ * flush it in order to avoid potential TLB entry duplication.
*/
- local_flush_tlb_one(get_asid(), address & PAGE_MASK);
+ if (writeaccess == 2)
+ local_flush_tlb_one(get_asid(), address & PAGE_MASK);
#endif
- set_pte(pte, entry);
update_mmu_cache(NULL, address, entry);
- ret = 0;
-out:
- return ret;
+ return 0;
}
