[PATCH -mm 5/6] remove MIPS arch_get_unmapped_area code

Rik van Riel
2012-06-18T15:20:04Z

From: Rik van Riel <riel@surriel.com>

Remove all the MIPS specific arch_get_unmapped_area(_topdown) and
page colouring code, now that the generic code should be able to
handle things.

Untested, because I do not have any MIPS systems.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: sjhill@mips.com
Signed-off-by: Rik van Riel <riel@redhat.com>
---
arch/mips/include/asm/pgtable.h | 8 --
arch/mips/mm/mmap.c | 175 ---------------------------------------
2 files changed, 0 insertions(+), 183 deletions(-)

diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index f133a4c..5f9c49a 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -410,14 +410,6 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
#endif

/*
- * We provide our own get_unmapped area to cope with the virtual aliasing
- * constraints placed on us by the cache architecture.
- */
-#define HAVE_ARCH_UNMAPPED_AREA
-#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
-#define HAVE_ARCH_ALIGN_ADDR
-
-/*
* No page table caches to initialise
*/
#define pgtable_cache_init() do { } while (0)
diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c
index 3f8af17..ac342bd 100644
--- a/arch/mips/mm/mmap.c
+++ b/arch/mips/mm/mmap.c
@@ -15,9 +15,6 @@
#include <linux/random.h>
#include <linux/sched.h>

-unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */
-EXPORT_SYMBOL(shm_align_mask);
-
/* gap between mmap and stack */
#define MIN_GAP (128*1024*1024UL)
#define MAX_GAP ((TASK_SIZE)/6*5)
@@ -45,178 +42,6 @@ static unsigned long mmap_base(unsigned long rnd)
return PAGE_ALIGN(TASK_SIZE - gap - rnd);
}

-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;
-}
-
-#define COLOUR_ALIGN(addr, pgoff) \
- ((((addr) + shm_align_mask) & ~shm_align_mask) + \
- (((pgoff) << PAGE_SHIFT) & shm_align_mask))
-
-static unsigned long arch_get_unmapped_area_common(struct file *filp,
- unsigned long addr0, unsigned long len, unsigned long pgoff,
- unsigned long flags, enum mmap_allocation_direction dir)
-{
- struct mm_struct *mm = current->mm;
- struct vm_area_struct *vma;
- unsigned long addr = addr0;
- int do_color_align;
-
- if (unlikely(len > TASK_SIZE))
- return -ENOMEM;
-
- if (flags & MAP_FIXED) {
- /* Even MAP_FIXED mappings must reside within TASK_SIZE */
- if (TASK_SIZE - len < addr)
- return -EINVAL;
-
- /*
- * 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;
- }
-
- do_color_align = 0;
- if (filp || (flags & MAP_SHARED))
- do_color_align = 1;
-
- /* requesting a specific address */
- if (addr) {
- if (do_color_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 (dir == ALLOC_UP) {
- addr = mm->mmap_base;
- if (do_color_align)
- addr = COLOUR_ALIGN(addr, pgoff);
- else
- addr = PAGE_ALIGN(addr);
-
- for (vma = find_vma(current->mm, addr); ; vma = vma->vm_next) {
- /* At this point: (!vma || addr < vma->vm_end). */
- if (TASK_SIZE - len < addr)
- return -ENOMEM;
- if (!vma || addr + len <= vma->vm_start)
- return addr;
- addr = vma->vm_end;
- if (do_color_align)
- addr = COLOUR_ALIGN(addr, pgoff);
- }
- } else {
- /* 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 the mapping can't fit into
- * the requested address hole
- */
- addr = mm->free_area_cache;
- if (do_color_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) {
- /* cache 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_color_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)) {
- /* cache 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_color_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;
- }
-}
-
-unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr0,
- unsigned long len, unsigned long pgoff, unsigned long flags)
-{
- return arch_get_unmapped_area_common(filp,
- addr0, len, pgoff, flags, ALLOC_UP);
-}
-
-/*
- * There is no need to export this but sched.h declares the function as
- * extern so making it static here results in an error.
- */
-unsigned long arch_get_unmapped_area_topdown(struct file *filp,
- unsigned long addr0, unsigned long len, unsigned long pgoff,
- unsigned long flags)
-{
- return arch_get_unmapped_area_common(filp,
- addr0, len, pgoff, flags, ALLOC_DOWN);
-}
-
void arch_pick_mmap_layout(struct mm_struct *mm)
{
unsigned long random_factor = 0UL;
--
1.7.7.6