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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/cris/mm/ioremap.c
downloadlinux-stericsson-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/cris/mm/ioremap.c')
-rw-r--r--arch/cris/mm/ioremap.c146
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));
+}