[PATCH -mm 6/6] remove ARM arch_get_unmapped_area functions

Rik van Riel
2012-06-18T15:18:07Z

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

Remove the ARM special variants of arch_get_unmapped_area since the
generic functions should now be able to handle everything.

Untested because I have no ARM hardware.

Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Rik van Riel <riel@redhat.com>
---
arch/arm/include/asm/pgtable.h | 6 -
arch/arm/mm/init.c | 3 +
arch/arm/mm/mmap.c | 217 +---------------------------------------
3 files changed, 4 insertions(+), 222 deletions(-)

diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index f66626d..6754183 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -296,12 +296,6 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
#include <asm-generic/pgtable.h>

/*
- * We provide our own arch_get_unmapped_area to cope with VIPT caches.
- */
-#define HAVE_ARCH_UNMAPPED_AREA
-#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
-
-/*
* remap a physical page `pfn' of size `size' with page protection `prot'
* into virtual address `from'
*/
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index f54d592..534dd96 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -600,6 +600,9 @@ void __init mem_init(void)
extern u32 itcm_end;
#endif

+ /* Tell the page colouring code what we need. */
+ shm_align_mask = SHMLBA - 1;
+
max_mapnr = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;

/* this will put all unused low memory onto the freelists */
diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
index ce8cb19..2b1f881 100644
--- a/arch/arm/mm/mmap.c
+++ b/arch/arm/mm/mmap.c
@@ -11,21 +11,7 @@
#include <linux/random.h>
#include <asm/cachetype.h>

-static inline unsigned long COLOUR_ALIGN_DOWN(unsigned long addr,
- unsigned long pgoff)
-{
- unsigned long base = addr & ~(SHMLBA-1);
- unsigned long off = (pgoff << PAGE_SHIFT) & (SHMLBA-1);
-
- if (base + off <= addr)
- return base + off;
-
- return base - off;
-}
-
-#define COLOUR_ALIGN(addr,pgoff) \
- ((((addr)+SHMLBA-1)&~(SHMLBA-1)) + \
- (((pgoff)<<PAGE_SHIFT) & (SHMLBA-1)))
+unsigned long shm_align_mask = SHMLBA - 1;

/* gap between mmap and stack */
#define MIN_GAP (128*1024*1024UL)
@@ -54,207 +40,6 @@ static unsigned long mmap_base(unsigned long rnd)
return PAGE_ALIGN(TASK_SIZE - gap - rnd);
}

-/*
- * We need to ensure that shared mappings are correctly aligned to
- * avoid aliasing issues with VIPT caches. We need to ensure that
- * a specific page of an object is always mapped at a multiple of
- * SHMLBA bytes.
- *
- * We unconditionally provide this function for all cases, however
- * in the VIVT case, we optimise out the alignment rules.
- */
-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_align = 0;
- int aliasing = cache_is_vipt_aliasing();
-
- /*
- * We only need to do colour alignment if either the I or D
- * caches alias.
- */
- if (aliasing)
- do_align = filp || (flags & MAP_SHARED);
-
- /*
- * We enforce the MAP_FIXED case.
- */
- if (flags & MAP_FIXED) {
- if (aliasing && flags & MAP_SHARED &&
- (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
- return -EINVAL;
- return addr;
- }
-
- if (len > TASK_SIZE)
- return -ENOMEM;
-
- if (addr) {
- if (do_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 {
- start_addr = addr = mm->mmap_base;
- mm->cached_hole_size = 0;
- }
-
-full_search:
- if (do_align)
- addr = COLOUR_ALIGN(addr, pgoff);
- else
- addr = PAGE_ALIGN(addr);
-
- for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
- /* At this point: (!vma || addr < vma->vm_end). */
- if (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 (!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_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_align = 0;
- int aliasing = cache_is_vipt_aliasing();
-
- /*
- * We only need to do colour alignment if either the I or D
- * caches alias.
- */
- if (aliasing)
- do_align = filp || (flags & MAP_SHARED);
-
- /* requested length too big for entire address space */
- if (len > TASK_SIZE)
- return -ENOMEM;
-
- if (flags & MAP_FIXED) {
- if (aliasing && flags & MAP_SHARED &&
- (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
- return -EINVAL;
- return addr;
- }
-
- /* requesting a specific address */
- if (addr) {
- if (do_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_align) {
- unsigned long base = COLOUR_ALIGN_DOWN(addr - len, pgoff);
- addr = base + len;
- }
-
- /* make sure it can fit in the remaining address space */
- if (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 (mm->mmap_base < len)
- goto bottomup;
-
- addr = mm->mmap_base - len;
- if (do_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 (!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_align)
- addr = COLOUR_ALIGN_DOWN(addr, pgoff);
- } while (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;
-}
-
void arch_pick_mmap_layout(struct mm_struct *mm)
{
unsigned long random_factor = 0UL;
--
1.7.7.6