1 files changed, 202 insertions, 0 deletions

diff --git a/arch/mips/mm/ioremap.c b/arch/mips/mm/ioremap.c
new file mode 100644
index 000000000000..adf352273f63
--- /dev/null
+++ b/arch/mips/mm/ioremap.c
@@ -0,0 +1,202 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * (C) Copyright 1995 1996 Linus Torvalds
+ * (C) Copyright 2001, 2002 Ralf Baechle
+ */
+#include <linux/module.h>
+#include <asm/addrspace.h>
+#include <asm/byteorder.h>
+
+#include <linux/vmalloc.h>
+#include <asm/cacheflush.h>
+#include <asm/io.h>
+#include <asm/tlbflush.h>
+
+static inline void remap_area_pte(pte_t * pte, unsigned long address,
+        phys_t size, phys_t phys_addr, unsigned long flags)
+{
+        phys_t end;
+        unsigned long pfn;
+        pgprot_t pgprot = __pgprot(_PAGE_GLOBAL | _PAGE_PRESENT | __READABLE
+                                   | __WRITEABLE | flags);
+
+        address &= ~PMD_MASK;
+        end = address + size;
+        if (end > PMD_SIZE)
+                end = PMD_SIZE;
+        if (address >= end)
+                BUG();
+        pfn = phys_addr >> PAGE_SHIFT;
+        do {
+                if (!pte_none(*pte)) {
+                        printk("remap_area_pte: page already exists\n");
+                        BUG();
+                }
+                set_pte(pte, pfn_pte(pfn, pgprot));
+                address += PAGE_SIZE;
+                pfn++;
+                pte++;
+        } while (address && (address < end));
+}
+
+static inline int remap_area_pmd(pmd_t * pmd, unsigned long address,
+        phys_t size, phys_t phys_addr, unsigned long flags)
+{
+        phys_t 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, phys_t phys_addr,
+        phys_t 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;
+}
+
+/*
+ * Allow physical addresses to be fixed up to help 36 bit peripherals.
+ */
+phys_t __attribute__ ((weak))
+fixup_bigphys_addr(phys_t phys_addr, phys_t size)
+{
+        return phys_addr;
+}
+
+/*
+ * 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.
+ */
+
+#define IS_LOW512(addr) (!((phys_t)(addr) & (phys_t) ~0x1fffffffULL))
+
+void * __ioremap(phys_t phys_addr, phys_t size, unsigned long flags)
+{
+        struct vm_struct * area;
+        unsigned long offset;
+        phys_t last_addr;
+        void * addr;
+
+        phys_addr = fixup_bigphys_addr(phys_addr, size);
+
+        /* Don't allow wraparound or zero size */
+        last_addr = phys_addr + size - 1;
+        if (!size || last_addr < phys_addr)
+                return NULL;
+
+        /*
+         * Map uncached objects in the low 512mb of address space using KSEG1,
+         * otherwise map using page tables.
+         */
+        if (IS_LOW512(phys_addr) && IS_LOW512(last_addr) &&
+            flags == _CACHE_UNCACHED)
+                return (void *) KSEG1ADDR(phys_addr);
+
+        /*
+         * Don't allow anybody to remap normal RAM that we're using..
+         */
+        if (phys_addr < virt_to_phys(high_memory)) {
+                char *t_addr, *t_end;
+                struct page *page;
+
+                t_addr = __va(phys_addr);
+                t_end = t_addr + (size - 1);
+
+                for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++)
+                        if(!PageReserved(page))
+                                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)) {
+                vunmap(addr);
+                return NULL;
+        }
+
+        return (void *) (offset + (char *)addr);
+}
+
+#define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == KSEG1)
+
+void __iounmap(volatile void __iomem *addr)
+{
+        struct vm_struct *p;
+
+        if (IS_KSEG1(addr))
+                return;
+
+        p = remove_vm_area((void *) (PAGE_MASK & (unsigned long __force) addr));
+        if (!p) {
+                printk(KERN_ERR "iounmap: bad address %p\n", addr);
+                return;
+        }
+
+        kfree(p);
+}
+
+EXPORT_SYMBOL(__ioremap);
+EXPORT_SYMBOL(__iounmap);