MIPS: Shrink the size of tlb handler

By combining swapper_pg_dir and module_pg_dir, several if conditions
can be eliminated from the tlb exception handler. The reason they
can be combined is that, the effective virtual address of vmalloc
returned is at the bottom, and of module_alloc returned is at the
top. It also fixes the bug in vmalloc(), which happens when its
return address is not covered by the first pgd.

Signed-off-by: Wu Fei <at.wufei@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/include/asm/pgtable-64.h b/arch/mips/include/asm/pgtable-64.h
index 4ed9d1bba2ba7d10244bd6a7884651f0cbeea076..9cd508993956b325d71dd654255d1a2aa92a459f 100644 (file)
--- a/arch/mips/include/asm/pgtable-64.h
+++ b/arch/mips/include/asm/pgtable-64.h
@@ -109,13 +109,13 @@
 
 #define VMALLOC_START          MAP_BASE
 #define VMALLOC_END    \
-       (VMALLOC_START + PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE)
+       (VMALLOC_START + \
+        PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE - (1UL << 32))
 #if defined(CONFIG_MODULES) && defined(KBUILD_64BIT_SYM32) && \
        VMALLOC_START != CKSSEG
 /* Load modules into 32bit-compatible segment. */
 #define MODULE_START   CKSSEG
 #define MODULE_END     (FIXADDR_START-2*PAGE_SIZE)
-extern pgd_t module_pg_dir[PTRS_PER_PGD];
 #endif
 
 #define pte_ERROR(e) \
@@ -188,12 +188,7 @@ static inline void pud_clear(pud_t *pudp)
 #define __pmd_offset(address)  pmd_index(address)
 
 /* to find an entry in a kernel page-table-directory */
-#ifdef MODULE_START
-#define pgd_offset_k(address) \
-       ((address) >= MODULE_START ? module_pg_dir : pgd_offset(&init_mm, 0UL))
-#else
-#define pgd_offset_k(address) pgd_offset(&init_mm, 0UL)
-#endif
+#define pgd_offset_k(address) pgd_offset(&init_mm, address)
 
 #define pgd_index(address)     (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
 #define pmd_index(address)     (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))

diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 0e820508ff23fd8bbfe8a4642c5f9acf1c3a9e73..38c79c55b060f3dcccfb4637f9eb33a44668b490 100644 (file)
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -475,9 +475,6 @@ unsigned long pgd_current[NR_CPUS];
  */
 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __page_aligned(_PGD_ORDER);
 #ifdef CONFIG_64BIT
-#ifdef MODULE_START
-pgd_t module_pg_dir[PTRS_PER_PGD] __page_aligned(PGD_ORDER);
-#endif
 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned(PMD_ORDER);
 #endif
 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);

diff --git a/arch/mips/mm/pgtable-64.c b/arch/mips/mm/pgtable-64.c
index e4b565aeb00807ec1c851c2ad665e1fb5b158255..1121019fa45652cb953dfd59014ee21b3fee430f 100644 (file)
--- a/arch/mips/mm/pgtable-64.c
+++ b/arch/mips/mm/pgtable-64.c
@@ -59,9 +59,6 @@ void __init pagetable_init(void)
 
        /* Initialize the entire pgd.  */
        pgd_init((unsigned long)swapper_pg_dir);
-#ifdef MODULE_START
-       pgd_init((unsigned long)module_pg_dir);
-#endif
        pmd_init((unsigned long)invalid_pmd_table, (unsigned long)invalid_pte_table);
 
        pgd_base = swapper_pg_dir;

diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index 9a17bf8395df1c92be94a48a6820891623154fe6..bc66f57f3257e07785c6fa138ce72ccc866e4726 100644 (file)
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -499,11 +499,7 @@ build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
         * The vmalloc handling is not in the hotpath.
         */
        uasm_i_dmfc0(p, tmp, C0_BADVADDR);
-#ifdef MODULE_START
-       uasm_il_bltz(p, r, tmp, label_module_alloc);
-#else
        uasm_il_bltz(p, r, tmp, label_vmalloc);
-#endif
        /* No uasm_i_nop needed here, since the next insn doesn't touch TMP. */
 
 #ifdef CONFIG_SMP
@@ -556,52 +552,7 @@ build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
 {
        long swpd = (long)swapper_pg_dir;
 
-#ifdef MODULE_START
-       long modd = (long)module_pg_dir;
-
-       uasm_l_module_alloc(l, *p);
-       /*
-        * Assumption:
-        * VMALLOC_START >= 0xc000000000000000UL
-        * MODULE_START >= 0xe000000000000000UL
-        */
-       UASM_i_SLL(p, ptr, bvaddr, 2);
-       uasm_il_bgez(p, r, ptr, label_vmalloc);
-
-       if (uasm_in_compat_space_p(MODULE_START) &&
-           !uasm_rel_lo(MODULE_START)) {
-               uasm_i_lui(p, ptr, uasm_rel_hi(MODULE_START)); /* delay slot */
-       } else {
-               /* unlikely configuration */
-               uasm_i_nop(p); /* delay slot */
-               UASM_i_LA(p, ptr, MODULE_START);
-       }
-       uasm_i_dsubu(p, bvaddr, bvaddr, ptr);
-
-       if (uasm_in_compat_space_p(modd) && !uasm_rel_lo(modd)) {
-               uasm_il_b(p, r, label_vmalloc_done);
-               uasm_i_lui(p, ptr, uasm_rel_hi(modd));
-       } else {
-               UASM_i_LA_mostly(p, ptr, modd);
-               uasm_il_b(p, r, label_vmalloc_done);
-               if (uasm_in_compat_space_p(modd))
-                       uasm_i_addiu(p, ptr, ptr, uasm_rel_lo(modd));
-               else
-                       uasm_i_daddiu(p, ptr, ptr, uasm_rel_lo(modd));
-       }
-
        uasm_l_vmalloc(l, *p);
-       if (uasm_in_compat_space_p(MODULE_START) &&
-           !uasm_rel_lo(MODULE_START) &&
-           MODULE_START << 32 == VMALLOC_START)
-               uasm_i_dsll32(p, ptr, ptr, 0);  /* typical case */
-       else
-               UASM_i_LA(p, ptr, VMALLOC_START);
-#else
-       uasm_l_vmalloc(l, *p);
-       UASM_i_LA(p, ptr, VMALLOC_START);
-#endif
-       uasm_i_dsubu(p, bvaddr, bvaddr, ptr);
 
        if (uasm_in_compat_space_p(swpd) && !uasm_rel_lo(swpd)) {
                uasm_il_b(p, r, label_vmalloc_done);