1 files changed, 146 insertions, 0 deletions

diff --git a/arch/cris/mm/ioremap.c b/arch/cris/mm/ioremap.c
new file mode 100644
index 000000000000..6b9130bfb6c1
--- /dev/null
+++ b/arch/cris/mm/ioremap.c
@@ -0,0 +1,146 @@
+/*
+ * arch/cris/mm/ioremap.c
+ *
+ * Re-map IO memory to kernel address space so that we can access it.
+ * Needed for memory-mapped I/O devices mapped outside our normal DRAM
+ * window (that is, all memory-mapped I/O devices).
+ *
+ * (C) Copyright 1995 1996 Linus Torvalds
+ * CRIS-port by Axis Communications AB
+ */
+
+#include <linux/vmalloc.h>
+#include <asm/io.h>
+#include <asm/pgalloc.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+
+extern inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned long size,
+        unsigned long phys_addr, unsigned long flags)
+{
+        unsigned long end;
+
+        address &= ~PMD_MASK;
+        end = address + size;
+        if (end > PMD_SIZE)
+                end = PMD_SIZE;
+        if (address >= end)
+                BUG();
+        do {
+                if (!pte_none(*pte)) {
+                        printk("remap_area_pte: page already exists\n");
+                        BUG();
+                }
+                set_pte(pte, mk_pte_phys(phys_addr, __pgprot(_PAGE_PRESENT | __READABLE | 
+                                                             __WRITEABLE | _PAGE_GLOBAL |
+                                                             _PAGE_KERNEL | flags)));
+                address += PAGE_SIZE;
+                phys_addr += PAGE_SIZE;
+                pte++;
+        } while (address && (address < end));
+}
+
+static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,
+        unsigned long phys_addr, unsigned long flags)
+{
+        unsigned long end;
+
+        address &= ~PGDIR_MASK;
+        end = address + size;
+        if (end > PGDIR_SIZE)
+                end = PGDIR_SIZE;
+        phys_addr -= address;
+        if (address >= end)
+                BUG();
+        do {
+                pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
+                if (!pte)
+                        return -ENOMEM;
+                remap_area_pte(pte, address, end - address, address + phys_addr, flags);
+                address = (address + PMD_SIZE) & PMD_MASK;
+                pmd++;
+        } while (address && (address < end));
+        return 0;
+}
+
+static int remap_area_pages(unsigned long address, unsigned long phys_addr,
+                                 unsigned long size, unsigned long flags)
+{
+        int error;
+        pgd_t * dir;
+        unsigned long end = address + size;
+
+        phys_addr -= address;
+        dir = pgd_offset(&init_mm, address);
+        flush_cache_all();
+        if (address >= end)
+                BUG();
+        spin_lock(&init_mm.page_table_lock);
+        do {
+                pmd_t *pmd;
+                pmd = pmd_alloc(&init_mm, dir, address);
+                error = -ENOMEM;
+                if (!pmd)
+                        break;
+                if (remap_area_pmd(pmd, address, end - address,
+                                   phys_addr + address, flags))
+                        break;
+                error = 0;
+                address = (address + PGDIR_SIZE) & PGDIR_MASK;
+                dir++;
+        } while (address && (address < end));
+        spin_unlock(&init_mm.page_table_lock);
+        flush_tlb_all();
+        return error;
+}
+
+/*
+ * Generic mapping function (not visible outside):
+ */
+
+/*
+ * Remap an arbitrary physical address space into the kernel virtual
+ * address space. Needed when the kernel wants to access high addresses
+ * directly.
+ *
+ * NOTE! We need to allow non-page-aligned mappings too: we will obviously
+ * have to convert them into an offset in a page-aligned mapping, but the
+ * caller shouldn't need to know that small detail.
+ */
+void * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
+{
+        void * addr;
+        struct vm_struct * area;
+        unsigned long offset, last_addr;
+
+        /* Don't allow wraparound or zero size */
+        last_addr = phys_addr + size - 1;
+        if (!size || last_addr < phys_addr)
+                return NULL;
+
+        /*
+         * Mappings have to be page-aligned
+         */
+        offset = phys_addr & ~PAGE_MASK;
+        phys_addr &= PAGE_MASK;
+        size = PAGE_ALIGN(last_addr+1) - phys_addr;
+
+        /*
+         * Ok, go for it..
+         */
+        area = get_vm_area(size, VM_IOREMAP);
+        if (!area)
+                return NULL;
+        addr = area->addr;
+        if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
+                vfree(addr);
+                return NULL;
+        }
+        return (void *) (offset + (char *)addr);
+}
+
+void iounmap(void *addr)
+{
+        if (addr > high_memory)
+                return vfree((void *) (PAGE_MASK & (unsigned long) addr));
+}