[POWERPC] Port fixmap from x86 and use for kmap_atomic

[linux-2.6-omap-h63xx.git] / include / asm-powerpc / highmem.h

diff --git a/include/asm-powerpc/highmem.h b/include/asm-powerpc/highmem.h
index f7b21ee302b4f1b7fcd1e923fa14c3da0e708f6e..5d99b6489d569d44e54a3781734e797d72100b5c 100644 (file)
--- a/include/asm-powerpc/highmem.h
+++ b/include/asm-powerpc/highmem.h
@@ -27,9 +27,7 @@
 #include <asm/kmap_types.h>
 #include <asm/tlbflush.h>
 #include <asm/page.h>
-
-/* undef for production */
-#define HIGHMEM_DEBUG 1
+#include <asm/fixmap.h>
 
 extern pte_t *kmap_pte;
 extern pgprot_t kmap_prot;
@@ -40,14 +38,12 @@ extern pte_t *pkmap_page_table;
  * easily, subsequent pte tables have to be allocated in one physical
  * chunk of RAM.
  */
-#define PKMAP_BASE     CONFIG_HIGHMEM_START
 #define LAST_PKMAP     (1 << PTE_SHIFT)
 #define LAST_PKMAP_MASK (LAST_PKMAP-1)
+#define PKMAP_BASE     ((FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) & PMD_MASK)
 #define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-#define KMAP_FIX_BEGIN (PKMAP_BASE + 0x00400000UL)
-
 extern void *kmap_high(struct page *page);
 extern void kunmap_high(struct page *page);
 
@@ -73,7 +69,7 @@ static inline void kunmap(struct page *page)
  * be used in IRQ contexts, so in some (very limited) cases we need
  * it.
  */
-static inline void *kmap_atomic(struct page *page, enum km_type type)
+static inline void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot)
 {
        unsigned int idx;
        unsigned long vaddr;
@@ -84,34 +80,39 @@ static inline void *kmap_atomic(struct page *page, enum km_type type)
                return page_address(page);
 
        idx = type + KM_TYPE_NR*smp_processor_id();
-       vaddr = KMAP_FIX_BEGIN + idx * PAGE_SIZE;
-#ifdef HIGHMEM_DEBUG
-       BUG_ON(!pte_none(*(kmap_pte+idx)));
+       vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+#ifdef CONFIG_DEBUG_HIGHMEM
+       BUG_ON(!pte_none(*(kmap_pte-idx)));
 #endif
-       set_pte_at(&init_mm, vaddr, kmap_pte+idx, mk_pte(page, kmap_prot));
+       set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot));
        flush_tlb_page(NULL, vaddr);
 
        return (void*) vaddr;
 }
 
+static inline void *kmap_atomic(struct page *page, enum km_type type)
+{
+       return kmap_atomic_prot(page, type, kmap_prot);
+}
+
 static inline void kunmap_atomic(void *kvaddr, enum km_type type)
 {
-#ifdef HIGHMEM_DEBUG
+#ifdef CONFIG_DEBUG_HIGHMEM
        unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
-       unsigned int idx = type + KM_TYPE_NR*smp_processor_id();
+       enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();
 
-       if (vaddr < KMAP_FIX_BEGIN) { // FIXME
+       if (vaddr < __fix_to_virt(FIX_KMAP_END)) {
                pagefault_enable();
                return;
        }
 
-       BUG_ON(vaddr != KMAP_FIX_BEGIN + idx * PAGE_SIZE);
+       BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
 
        /*
         * force other mappings to Oops if they'll try to access
         * this pte without first remap it
         */
-       pte_clear(&init_mm, vaddr, kmap_pte+idx);
+       pte_clear(&init_mm, vaddr, kmap_pte-idx);
        flush_tlb_page(NULL, vaddr);
 #endif
        pagefault_enable();
@@ -120,12 +121,14 @@ static inline void kunmap_atomic(void *kvaddr, enum km_type type)
 static inline struct page *kmap_atomic_to_page(void *ptr)
 {
        unsigned long idx, vaddr = (unsigned long) ptr;
+       pte_t *pte;
 
-       if (vaddr < KMAP_FIX_BEGIN)
+       if (vaddr < FIXADDR_START)
                return virt_to_page(ptr);
 
-       idx = (vaddr - KMAP_FIX_BEGIN) >> PAGE_SHIFT;
-       return pte_page(kmap_pte[idx]);
+       idx = virt_to_fix(vaddr);
+       pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
+       return pte_page(*pte);
 }
 
 #define flush_cache_kmaps()    flush_cache_all()