![Paul Mundt](/assets/img/avatar_default.png)
Presently shm_align_mask is only looked at for the bottom up case, but we still want this for proper colouring constraints in the topdown case. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
254 lines
6.1 KiB
C
254 lines
6.1 KiB
C
/*
|
|
* arch/sh/mm/mmap.c
|
|
*
|
|
* Copyright (C) 2008 - 2009 Paul Mundt
|
|
*
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
|
* License. See the file "COPYING" in the main directory of this archive
|
|
* for more details.
|
|
*/
|
|
#include <linux/io.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/mman.h>
|
|
#include <linux/module.h>
|
|
#include <asm/page.h>
|
|
#include <asm/processor.h>
|
|
|
|
#ifdef CONFIG_MMU
|
|
unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */
|
|
EXPORT_SYMBOL(shm_align_mask);
|
|
|
|
/*
|
|
* To avoid cache aliases, we map the shared page with same color.
|
|
*/
|
|
static inline unsigned long COLOUR_ALIGN(unsigned long addr,
|
|
unsigned long pgoff)
|
|
{
|
|
unsigned long base = (addr + shm_align_mask) & ~shm_align_mask;
|
|
unsigned long off = (pgoff << PAGE_SHIFT) & shm_align_mask;
|
|
|
|
return base + off;
|
|
}
|
|
|
|
static inline unsigned long COLOUR_ALIGN_DOWN(unsigned long addr,
|
|
unsigned long pgoff)
|
|
{
|
|
unsigned long base = addr & ~shm_align_mask;
|
|
unsigned long off = (pgoff << PAGE_SHIFT) & shm_align_mask;
|
|
|
|
if (base + off <= addr)
|
|
return base + off;
|
|
|
|
return base - off;
|
|
}
|
|
|
|
unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
|
|
unsigned long len, unsigned long pgoff, unsigned long flags)
|
|
{
|
|
struct mm_struct *mm = current->mm;
|
|
struct vm_area_struct *vma;
|
|
unsigned long start_addr;
|
|
int do_colour_align;
|
|
|
|
if (flags & MAP_FIXED) {
|
|
/* We do not accept a shared mapping if it would violate
|
|
* cache aliasing constraints.
|
|
*/
|
|
if ((flags & MAP_SHARED) && (addr & shm_align_mask))
|
|
return -EINVAL;
|
|
return addr;
|
|
}
|
|
|
|
if (unlikely(len > TASK_SIZE))
|
|
return -ENOMEM;
|
|
|
|
do_colour_align = 0;
|
|
if (filp || (flags & MAP_SHARED))
|
|
do_colour_align = 1;
|
|
|
|
if (addr) {
|
|
if (do_colour_align)
|
|
addr = COLOUR_ALIGN(addr, pgoff);
|
|
else
|
|
addr = PAGE_ALIGN(addr);
|
|
|
|
vma = find_vma(mm, addr);
|
|
if (TASK_SIZE - len >= addr &&
|
|
(!vma || addr + len <= vma->vm_start))
|
|
return addr;
|
|
}
|
|
|
|
if (len > mm->cached_hole_size) {
|
|
start_addr = addr = mm->free_area_cache;
|
|
} else {
|
|
mm->cached_hole_size = 0;
|
|
start_addr = addr = TASK_UNMAPPED_BASE;
|
|
}
|
|
|
|
full_search:
|
|
if (do_colour_align)
|
|
addr = COLOUR_ALIGN(addr, pgoff);
|
|
else
|
|
addr = PAGE_ALIGN(mm->free_area_cache);
|
|
|
|
for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
|
|
/* At this point: (!vma || addr < vma->vm_end). */
|
|
if (unlikely(TASK_SIZE - len < addr)) {
|
|
/*
|
|
* Start a new search - just in case we missed
|
|
* some holes.
|
|
*/
|
|
if (start_addr != TASK_UNMAPPED_BASE) {
|
|
start_addr = addr = TASK_UNMAPPED_BASE;
|
|
mm->cached_hole_size = 0;
|
|
goto full_search;
|
|
}
|
|
return -ENOMEM;
|
|
}
|
|
if (likely(!vma || addr + len <= vma->vm_start)) {
|
|
/*
|
|
* Remember the place where we stopped the search:
|
|
*/
|
|
mm->free_area_cache = addr + len;
|
|
return addr;
|
|
}
|
|
if (addr + mm->cached_hole_size < vma->vm_start)
|
|
mm->cached_hole_size = vma->vm_start - addr;
|
|
|
|
addr = vma->vm_end;
|
|
if (do_colour_align)
|
|
addr = COLOUR_ALIGN(addr, pgoff);
|
|
}
|
|
}
|
|
|
|
unsigned long
|
|
arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
|
const unsigned long len, const unsigned long pgoff,
|
|
const unsigned long flags)
|
|
{
|
|
struct vm_area_struct *vma;
|
|
struct mm_struct *mm = current->mm;
|
|
unsigned long addr = addr0;
|
|
int do_colour_align;
|
|
|
|
if (flags & MAP_FIXED) {
|
|
/* We do not accept a shared mapping if it would violate
|
|
* cache aliasing constraints.
|
|
*/
|
|
if ((flags & MAP_SHARED) &&
|
|
((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))
|
|
return -EINVAL;
|
|
return addr;
|
|
}
|
|
|
|
if (unlikely(len > TASK_SIZE))
|
|
return -ENOMEM;
|
|
|
|
do_colour_align = 0;
|
|
if (filp || (flags & MAP_SHARED))
|
|
do_colour_align = 1;
|
|
|
|
/* requesting a specific address */
|
|
if (addr) {
|
|
if (do_colour_align)
|
|
addr = COLOUR_ALIGN(addr, pgoff);
|
|
else
|
|
addr = PAGE_ALIGN(addr);
|
|
|
|
vma = find_vma(mm, addr);
|
|
if (TASK_SIZE - len >= addr &&
|
|
(!vma || addr + len <= vma->vm_start))
|
|
return addr;
|
|
}
|
|
|
|
/* check if free_area_cache is useful for us */
|
|
if (len <= mm->cached_hole_size) {
|
|
mm->cached_hole_size = 0;
|
|
mm->free_area_cache = mm->mmap_base;
|
|
}
|
|
|
|
/* either no address requested or can't fit in requested address hole */
|
|
addr = mm->free_area_cache;
|
|
if (do_colour_align) {
|
|
unsigned long base = COLOUR_ALIGN_DOWN(addr-len, pgoff);
|
|
|
|
addr = base + len;
|
|
}
|
|
|
|
/* make sure it can fit in the remaining address space */
|
|
if (likely(addr > len)) {
|
|
vma = find_vma(mm, addr-len);
|
|
if (!vma || addr <= vma->vm_start) {
|
|
/* remember the address as a hint for next time */
|
|
return (mm->free_area_cache = addr-len);
|
|
}
|
|
}
|
|
|
|
if (unlikely(mm->mmap_base < len))
|
|
goto bottomup;
|
|
|
|
addr = mm->mmap_base-len;
|
|
if (do_colour_align)
|
|
addr = COLOUR_ALIGN_DOWN(addr, pgoff);
|
|
|
|
do {
|
|
/*
|
|
* Lookup failure means no vma is above this address,
|
|
* else if new region fits below vma->vm_start,
|
|
* return with success:
|
|
*/
|
|
vma = find_vma(mm, addr);
|
|
if (likely(!vma || addr+len <= vma->vm_start)) {
|
|
/* remember the address as a hint for next time */
|
|
return (mm->free_area_cache = addr);
|
|
}
|
|
|
|
/* remember the largest hole we saw so far */
|
|
if (addr + mm->cached_hole_size < vma->vm_start)
|
|
mm->cached_hole_size = vma->vm_start - addr;
|
|
|
|
/* try just below the current vma->vm_start */
|
|
addr = vma->vm_start-len;
|
|
if (do_colour_align)
|
|
addr = COLOUR_ALIGN_DOWN(addr, pgoff);
|
|
} while (likely(len < vma->vm_start));
|
|
|
|
bottomup:
|
|
/*
|
|
* A failed mmap() very likely causes application failure,
|
|
* so fall back to the bottom-up function here. This scenario
|
|
* can happen with large stack limits and large mmap()
|
|
* allocations.
|
|
*/
|
|
mm->cached_hole_size = ~0UL;
|
|
mm->free_area_cache = TASK_UNMAPPED_BASE;
|
|
addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
|
|
/*
|
|
* Restore the topdown base:
|
|
*/
|
|
mm->free_area_cache = mm->mmap_base;
|
|
mm->cached_hole_size = ~0UL;
|
|
|
|
return addr;
|
|
}
|
|
#endif /* CONFIG_MMU */
|
|
|
|
/*
|
|
* You really shouldn't be using read() or write() on /dev/mem. This
|
|
* might go away in the future.
|
|
*/
|
|
int valid_phys_addr_range(unsigned long addr, size_t count)
|
|
{
|
|
if (addr < __MEMORY_START)
|
|
return 0;
|
|
if (addr + count > __pa(high_memory))
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
|
|
{
|
|
return 1;
|
|
}
|