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Commit 74588d8b authored by Haavard Skinnemoen's avatar Haavard Skinnemoen Committed by Linus Torvalds
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[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: default avatarHaavard 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: default avatarAdrian Bunk <bunk@stusta.de>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent bc03613d

include/linux/io.h

+4 −0
Original line number Diff line number Diff line
@@ -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 */

lib/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -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

lib/ioremap.c

0 → 100644
+94 −0
Original line number Diff line number Diff line 
/*

 * 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;

}