aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--include/linux/io.h4
-rw-r--r--lib/Makefile1
-rw-r--r--lib/ioremap.c94
3 files changed, 99 insertions, 0 deletions
diff --git a/include/linux/io.h b/include/linux/io.h
index 420e2fdf26f..aa3f5af670b 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -19,8 +19,12 @@
#define _LINUX_IO_H
#include <asm/io.h>
+#include <asm/page.h>
void __iowrite32_copy(void __iomem *to, const void *from, size_t count);
void __iowrite64_copy(void __iomem *to, const void *from, size_t count);
+int ioremap_page_range(unsigned long addr, unsigned long end,
+ unsigned long phys_addr, pgprot_t prot);
+
#endif /* _LINUX_IO_H */
diff --git a/lib/Makefile b/lib/Makefile
index 402762fead7..ddf3e676e1f 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -7,6 +7,7 @@ lib-y := errno.o ctype.o string.o vsprintf.o cmdline.o \
idr.o div64.o int_sqrt.o bitmap.o extable.o prio_tree.o \
sha1.o
+lib-$(CONFIG_MMU) += ioremap.o
lib-$(CONFIG_SMP) += cpumask.o
lib-y += kobject.o kref.o kobject_uevent.o klist.o
diff --git a/lib/ioremap.c b/lib/ioremap.c
new file mode 100644
index 00000000000..29c810ec981
--- /dev/null
+++ b/lib/ioremap.c
@@ -0,0 +1,94 @@
+/*
+ * Re-map IO memory to kernel address space so that we can access it.
+ * This is needed for high PCI addresses that aren't mapped in the
+ * 640k-1MB IO memory area on PC's
+ *
+ * (C) Copyright 1995 1996 Linus Torvalds
+ */
+#include <linux/io.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+
+#include <asm/cacheflush.h>
+#include <asm/pgtable.h>
+
+static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
+ unsigned long end, unsigned long phys_addr, pgprot_t prot)
+{
+ pte_t *pte;
+ unsigned long pfn;
+
+ pfn = phys_addr >> PAGE_SHIFT;
+ pte = pte_alloc_kernel(pmd, addr);
+ if (!pte)
+ return -ENOMEM;
+ do {
+ BUG_ON(!pte_none(*pte));
+ set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
+ pfn++;
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+ return 0;
+}
+
+static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
+ unsigned long end, unsigned long phys_addr, pgprot_t prot)
+{
+ pmd_t *pmd;
+ unsigned long next;
+
+ phys_addr -= addr;
+ pmd = pmd_alloc(&init_mm, pud, addr);
+ if (!pmd)
+ return -ENOMEM;
+ do {
+ next = pmd_addr_end(addr, end);
+ if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot))
+ return -ENOMEM;
+ } while (pmd++, addr = next, addr != end);
+ return 0;
+}
+
+static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
+ unsigned long end, unsigned long phys_addr, pgprot_t prot)
+{
+ pud_t *pud;
+ unsigned long next;
+
+ phys_addr -= addr;
+ pud = pud_alloc(&init_mm, pgd, addr);
+ if (!pud)
+ return -ENOMEM;
+ do {
+ next = pud_addr_end(addr, end);
+ if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot))
+ return -ENOMEM;
+ } while (pud++, addr = next, addr != end);
+ return 0;
+}
+
+int ioremap_page_range(unsigned long addr,
+ unsigned long end, unsigned long phys_addr, pgprot_t prot)
+{
+ pgd_t *pgd;
+ unsigned long start;
+ unsigned long next;
+ int err;
+
+ BUG_ON(addr >= end);
+
+ flush_cache_all();
+
+ start = addr;
+ phys_addr -= addr;
+ pgd = pgd_offset_k(addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, prot);
+ if (err)
+ break;
+ } while (pgd++, addr = next, addr != end);
+
+ flush_tlb_all();
+
+ return err;
+}