sh: Fix up and optimize the kmap_coherent() interface.

This fixes up the kmap_coherent/kunmap_coherent() interface for recent
changes both in the page fault path and the shared cache flushers, as
well as adding in some optimizations.

One of the key things to note here is that the TLB flush itself is
deferred until the unmap, and the call in to update_mmu_cache() itself
goes away, relying on the regular page fault path to handle the lazy
dcache writeback if necessary.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

8 files changed, 62 insertions, 48 deletions

diff --git a/arch/sh/include/asm/cacheflush.h b/arch/sh/include/asm/cacheflush.h
index 11e416630585..c29918f3c819 100644
--- a/arch/sh/include/asm/cacheflush.h
+++ b/arch/sh/include/asm/cacheflush.h
@@ -85,7 +85,7 @@ extern void copy_from_user_page(struct vm_area_struct *vma,
 
 void kmap_coherent_init(void);
 void *kmap_coherent(struct page *page, unsigned long addr);
-void kunmap_coherent(void);
+void kunmap_coherent(void *kvaddr);
 
 #define PG_dcache_dirty PG_arch_1
 
diff --git a/arch/sh/include/asm/pgtable_32.h b/arch/sh/include/asm/pgtable_32.h
index 4c4429cda56d..c0d359ce337b 100644
--- a/arch/sh/include/asm/pgtable_32.h
+++ b/arch/sh/include/asm/pgtable_32.h
@@ -408,13 +408,19 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 
 /* to find an entry in a page-table-directory. */
 #define pgd_index(address)      (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
-#define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))
+#define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
+#define __pgd_offset(address)   pgd_index(address)
 
 /* to find an entry in a kernel page-table-directory */
 #define pgd_offset_k(address)   pgd_offset(&init_mm, address)
 
+#define __pud_offset(address)   (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
+#define __pmd_offset(address)   (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
+
 /* Find an entry in the third-level page table.. */
 #define pte_index(address)      ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
+#define __pte_offset(address)   pte_index(address)
+
 #define pte_offset_kernel(dir, address) \
         ((pte_t *) pmd_page_vaddr(*(dir)) + pte_index(address))
 #define pte_offset_map(dir, address)            pte_offset_kernel(dir, address)
diff --git a/arch/sh/include/asm/pgtable_64.h b/arch/sh/include/asm/pgtable_64.h
index c78990cda557..17cdbecc3adc 100644
--- a/arch/sh/include/asm/pgtable_64.h
+++ b/arch/sh/include/asm/pgtable_64.h
@@ -60,6 +60,9 @@ static __inline__ void pmd_set(pmd_t *pmdp,pte_t *ptep)
 /* To find an entry in a kernel PGD. */
 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 
+#define __pud_offset(address)   (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
+#define __pmd_offset(address)   (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
+
 /*
  * PMD level access routines. Same notes as above.
  */
@@ -80,6 +83,8 @@ static __inline__ void pmd_set(pmd_t *pmdp,pte_t *ptep)
 #define pte_index(address) \
                 ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 
+#define __pte_offset(address)   pte_index(address)
+
 #define pte_offset_kernel(dir, addr) \
                 ((pte_t *) ((pmd_val(*(dir))) & PAGE_MASK) + pte_index((addr)))
 
diff --git a/arch/sh/mm/cache.c b/arch/sh/mm/cache.c
index db2b1c5beffd..8e4a8d1ac4a9 100644
--- a/arch/sh/mm/cache.c
+++ b/arch/sh/mm/cache.c
@@ -51,7 +51,7 @@ void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
             !test_bit(PG_dcache_dirty, &page->flags)) {
                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
                 memcpy(vto, src, len);
-                kunmap_coherent();
+                kunmap_coherent(vto);
         } else {
                 memcpy(dst, src, len);
                 if (boot_cpu_data.dcache.n_aliases)
@@ -70,7 +70,7 @@ void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
             !test_bit(PG_dcache_dirty, &page->flags)) {
                 void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
                 memcpy(dst, vfrom, len);
-                kunmap_coherent();
+                kunmap_coherent(vfrom);
         } else {
                 memcpy(dst, src, len);
                 if (boot_cpu_data.dcache.n_aliases)
@@ -89,7 +89,7 @@ void copy_user_highpage(struct page *to, struct page *from,
             !test_bit(PG_dcache_dirty, &from->flags)) {
                 vfrom = kmap_coherent(from, vaddr);
                 copy_page(vto, vfrom);
-                kunmap_coherent();
+                kunmap_coherent(vfrom);
         } else {
                 vfrom = kmap_atomic(from, KM_USER0);
                 copy_page(vto, vfrom);
@@ -150,7 +150,7 @@ void __flush_anon_page(struct page *page, unsigned long vmaddr)
 
                         kaddr = kmap_coherent(page, vmaddr);
                         __flush_wback_region((void *)kaddr, PAGE_SIZE);
-                        kunmap_coherent();
+                        kunmap_coherent(kaddr);
                 } else
                         __flush_wback_region((void *)addr, PAGE_SIZE);
         }
diff --git a/arch/sh/mm/fault_32.c b/arch/sh/mm/fault_32.c
index f1c93c880ed4..781b413ff82d 100644
--- a/arch/sh/mm/fault_32.c
+++ b/arch/sh/mm/fault_32.c
@@ -82,8 +82,8 @@ static noinline int vmalloc_fault(unsigned long address)
         pmd_t *pmd_k;
         pte_t *pte_k;
 
-        /* Make sure we are in vmalloc area: */
-        if (!(address >= VMALLOC_START && address < VMALLOC_END))
+        /* Make sure we are in vmalloc/module/P3 area: */
+        if (!(address >= VMALLOC_START && address < P3_ADDR_MAX))
                 return -1;
 
         /*
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 0a9b4d855bc9..edc842ff61ed 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -106,27 +106,31 @@ void __init page_table_range_init(unsigned long start, unsigned long end,
         pgd_t *pgd;
         pud_t *pud;
         pmd_t *pmd;
-        int pgd_idx;
+        pte_t *pte;
+        int i, j, k;
         unsigned long vaddr;
 
-        vaddr = start & PMD_MASK;
-        end = (end + PMD_SIZE - 1) & PMD_MASK;
-        pgd_idx = pgd_index(vaddr);
-        pgd = pgd_base + pgd_idx;
-
-        for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
-                BUG_ON(pgd_none(*pgd));
-                pud = pud_offset(pgd, 0);
-                BUG_ON(pud_none(*pud));
-                pmd = pmd_offset(pud, 0);
-
-                if (!pmd_present(*pmd)) {
-                        pte_t *pte_table;
-                        pte_table = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
-                        pmd_populate_kernel(&init_mm, pmd, pte_table);
+        vaddr = start;
+        i = __pgd_offset(vaddr);
+        j = __pud_offset(vaddr);
+        k = __pmd_offset(vaddr);
+        pgd = pgd_base + i;
+
+        for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
+                pud = (pud_t *)pgd;
+                for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
+                        pmd = (pmd_t *)pud;
+                        for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
+                                if (pmd_none(*pmd)) {
+                                        pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+                                        pmd_populate_kernel(&init_mm, pmd, pte);
+                                        BUG_ON(pte != pte_offset_kernel(pmd, 0));
+                                }
+                                vaddr += PMD_SIZE;
+                        }
+                        k = 0;
                 }
-
-                vaddr += PMD_SIZE;
+                j = 0;
         }
 }
 #endif  /* CONFIG_MMU */
@@ -137,7 +141,7 @@ void __init page_table_range_init(unsigned long start, unsigned long end,
 void __init paging_init(void)
 {
         unsigned long max_zone_pfns[MAX_NR_ZONES];
-        unsigned long vaddr;
+        unsigned long vaddr, end;
         int nid;
 
         /* We don't need to map the kernel through the TLB, as
@@ -155,7 +159,8 @@ void __init paging_init(void)
          * pte's will be filled in by __set_fixmap().
          */
         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
-        page_table_range_init(vaddr, 0, swapper_pg_dir);
+        end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
+        page_table_range_init(vaddr, end, swapper_pg_dir);
 
         kmap_coherent_init();
 
diff --git a/arch/sh/mm/kmap.c b/arch/sh/mm/kmap.c
index 3eecf0d42f1a..c52cd8c40a64 100644
--- a/arch/sh/mm/kmap.c
+++ b/arch/sh/mm/kmap.c
@@ -24,9 +24,6 @@ void __init kmap_coherent_init(void)
 {
         unsigned long vaddr;
 
-        if (!boot_cpu_data.dcache.n_aliases)
-                return;
-
         /* cache the first coherent kmap pte */
         vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
         kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
@@ -35,30 +32,31 @@ void __init kmap_coherent_init(void)
 void *kmap_coherent(struct page *page, unsigned long addr)
 {
         enum fixed_addresses idx;
-        unsigned long vaddr, flags;
-        pte_t pte;
+        unsigned long vaddr;
 
         BUG_ON(test_bit(PG_dcache_dirty, &page->flags));
 
-        inc_preempt_count();
-
-        idx = (addr & current_cpu_data.dcache.alias_mask) >> PAGE_SHIFT;
-        vaddr = __fix_to_virt(FIX_CMAP_END - idx);
-        pte = mk_pte(page, PAGE_KERNEL);
+        pagefault_disable();
 
-        local_irq_save(flags);
-        flush_tlb_one(get_asid(), vaddr);
-        local_irq_restore(flags);
+        idx = FIX_CMAP_END -
+                ((addr & current_cpu_data.dcache.alias_mask) >> PAGE_SHIFT);
+        vaddr = __fix_to_virt(idx);
 
-        update_mmu_cache(NULL, vaddr, pte);
-
-        set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);
+        BUG_ON(!pte_none(*(kmap_coherent_pte - idx)));
+        set_pte(kmap_coherent_pte - idx, mk_pte(page, PAGE_KERNEL));
 
         return (void *)vaddr;
 }
 
-void kunmap_coherent(void)
+void kunmap_coherent(void *kvaddr)
 {
-        dec_preempt_count();
-        preempt_check_resched();
+        if (kvaddr >= (void *)FIXADDR_START) {
+                unsigned long vaddr = (unsigned long)kvaddr & PAGE_MASK;
+                enum fixed_addresses idx = __virt_to_fix(vaddr);
+
+                pte_clear(&init_mm, vaddr, kmap_coherent_pte - idx);
+                local_flush_tlb_one(get_asid(), vaddr);
+        }
+
+        pagefault_enable();
 }
diff --git a/arch/sh/mm/nommu.c b/arch/sh/mm/nommu.c
index 51b54037216f..ac16c05917ef 100644
--- a/arch/sh/mm/nommu.c
+++ b/arch/sh/mm/nommu.c
@@ -81,7 +81,7 @@ void *kmap_coherent(struct page *page, unsigned long addr)
         return NULL;
 }
 
-void kunmap_coherent(void)
+void kunmap_coherent(void *kvaddr)
 {
         BUG();
 }