mirror of
https://github.com/adulau/aha.git
synced 2024-12-28 19:56:18 +00:00
db71daabad
The existing implementation of ioremap_page_range(), which was taken from i386, does this: flush_cache_all(); /* modify page tables */ flush_tlb_all(); I think this is a bit defensive, so this patch changes the generic implementation to do: /* modify page tables */ flush_cache_vmap(start, end); instead, which is similar to what vmalloc() does. This should still be correct because we never modify existing PTEs. According to James Bottomley: The problem the flush_tlb_all() is trying to solve is to avoid stale tlb entries in the ioremap area. We're just being conservative by flushing on both map and unmap. Technically what vmalloc/vfree does (only flush the tlb on unmap) is just fine because it means that the only tlb entries in the remap area must belong to in-use mappings. 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: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
92 lines
2.1 KiB
C
92 lines
2.1 KiB
C
/*
|
|
* 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);
|
|
|
|
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_cache_vmap(start, end);
|
|
|
|
return err;
|
|
}
|