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authorHaavard Skinnemoen <hskinnemoen@atmel.com>2006-09-30 23:29:12 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-10-01 00:39:31 -0700
commit74588d8ba34ff1bda027cfa737972af01ab00c8b (patch)
tree5e889e96d29c96e9c54ff72933de0612c61e9835 /lib/ioremap.c
parentbc03613decef0cc4d2f3a24f19fa5a868745715f (diff)
downloadlinux-74588d8ba34ff1bda027cfa737972af01ab00c8b.tar.gz
[PATCH] Generic ioremap_page_range: implementation
This patch adds a generic implementation of ioremap_page_range() in lib/ioremap.c based on the i386 implementation. It differs from the i386 version in the following ways: * The PTE flags are passed as a pgprot_t argument and must be determined up front by the arch-specific code. No additional PTE flags are added. * Uses set_pte_at() instead of set_pte() [bunk@stusta.de: warning fix] ]dhowells@redhat.com: nommu build fix] Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Mikael Starvik <starvik@axis.com> Cc: Andi Kleen <ak@suse.de> Cc: <linux-m32r@ml.linux-m32r.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Kyle McMartin <kyle@parisc-linux.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'lib/ioremap.c')
-rw-r--r--lib/ioremap.c94
1 files changed, 94 insertions, 0 deletions
diff --git a/lib/ioremap.c b/lib/ioremap.c
new file mode 100644
index 000000000000..29c810ec9813
--- /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;
+}