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/* $Id: generic.c,v 1.17 2001/04/09 04:08:06 davem Exp $
* generic.c: Generic Sparc mm routines that are not dependent upon
* MMU type but are Sparc specific.
*
* Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/pagemap.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/page.h>
static inline void forget_pte(pte_t page)
{
if (pte_none(page))
return;
if (pte_present(page)) {
struct page *ptpage = pte_page(page);
if ((!VALID_PAGE(ptpage)) || PageReserved(ptpage))
return;
page_cache_release(ptpage);
return;
}
swap_free(pte_to_swp_entry(page));
}
/* Remap IO memory, the same way as remap_page_range(), but use
* the obio memory space.
*
* They use a pgprot that sets PAGE_IO and does not check the
* mem_map table as this is independent of normal memory.
*
* As a special hack if the lowest bit of offset is set the
* side-effect bit will be turned off. This is used as a
* performance improvement on FFB/AFB. -DaveM
*/
static inline void io_remap_pte_range(pte_t * pte, unsigned long address, unsigned long size,
unsigned long offset, pgprot_t prot, int space)
{
unsigned long end;
address &= ~PMD_MASK;
end = address + size;
if (end > PMD_SIZE)
end = PMD_SIZE;
do {
pte_t oldpage;
pte_t entry;
unsigned long curend = address + PAGE_SIZE;
entry = mk_pte_io((offset & ~(0x1UL)), prot, space);
if (!(address & 0xffff)) {
if (!(address & 0x3fffff) && !(offset & 0x3ffffe) && end >= address + 0x400000) {
entry = mk_pte_io((offset & ~(0x1UL)),
__pgprot(pgprot_val (prot) | _PAGE_SZ4MB),
space);
curend = address + 0x400000;
offset += 0x400000;
} else if (!(address & 0x7ffff) && !(offset & 0x7fffe) && end >= address + 0x80000) {
entry = mk_pte_io((offset & ~(0x1UL)),
__pgprot(pgprot_val (prot) | _PAGE_SZ512K),
space);
curend = address + 0x80000;
offset += 0x80000;
} else if (!(offset & 0xfffe) && end >= address + 0x10000) {
entry = mk_pte_io((offset & ~(0x1UL)),
__pgprot(pgprot_val (prot) | _PAGE_SZ64K),
space);
curend = address + 0x10000;
offset += 0x10000;
} else
offset += PAGE_SIZE;
} else
offset += PAGE_SIZE;
if (offset & 0x1UL)
pte_val(entry) &= ~(_PAGE_E);
do {
oldpage = *pte;
pte_clear(pte);
set_pte(pte, entry);
forget_pte(oldpage);
address += PAGE_SIZE;
pte++;
} while (address < curend);
} while (address < end);
}
static inline int io_remap_pmd_range(pmd_t * pmd, unsigned long address, unsigned long size,
unsigned long offset, pgprot_t prot, int space)
{
unsigned long end;
address &= ~PGDIR_MASK;
end = address + size;
if (end > PGDIR_SIZE)
end = PGDIR_SIZE;
offset -= address;
do {
pte_t * pte = pte_alloc(current->mm, pmd, address);
if (!pte)
return -ENOMEM;
io_remap_pte_range(pte, address, end - address, address + offset, prot, space);
address = (address + PMD_SIZE) & PMD_MASK;
pmd++;
} while (address < end);
return 0;
}
int io_remap_page_range(unsigned long from, unsigned long offset, unsigned long size, pgprot_t prot, int space)
{
int error = 0;
pgd_t * dir;
unsigned long beg = from;
unsigned long end = from + size;
struct mm_struct *mm = current->mm;
prot = __pgprot(pg_iobits);
offset -= from;
dir = pgd_offset(mm, from);
flush_cache_range(mm, beg, end);
spin_lock(&mm->page_table_lock);
while (from < end) {
pmd_t *pmd = pmd_alloc(current->mm, dir, from);
error = -ENOMEM;
if (!pmd)
break;
error = io_remap_pmd_range(pmd, from, end - from, offset + from, prot, space);
if (error)
break;
from = (from + PGDIR_SIZE) & PGDIR_MASK;
dir++;
}
spin_unlock(&mm->page_table_lock);
flush_tlb_range(current->mm, beg, end);
return error;
}
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