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authorPaul Mundt <lethal@linux-sh.org>2006-09-27 18:36:17 +0900
committerPaul Mundt <lethal@linux-sh.org>2006-09-27 18:36:17 +0900
commitf3c2575818fab45f8609e4aef2e43ab02b3a142e (patch)
treea4924d7dd8f8df229e36fab24ccccfe12437509b /arch/sh/kernel/sys_sh.c
parent87b0ef91b6f27c07bf7dcce8584437481f473092 (diff)
sh: Calculate shm alignment at runtime.
Set the SHM alignment at runtime, based off of probed cache desc. Optimize get_unmapped_area() to only colour align shared mappings. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/kernel/sys_sh.c')
-rw-r--r--arch/sh/kernel/sys_sh.c54
1 files changed, 34 insertions, 20 deletions
diff --git a/arch/sh/kernel/sys_sh.c b/arch/sh/kernel/sys_sh.c
index 0ee7bf4cb238..b68ff705f067 100644
--- a/arch/sh/kernel/sys_sh.c
+++ b/arch/sh/kernel/sys_sh.c
@@ -21,6 +21,7 @@
#include <linux/mman.h>
#include <linux/file.h>
#include <linux/utsname.h>
+#include <linux/module.h>
#include <asm/cacheflush.h>
#include <asm/uaccess.h>
#include <asm/ipc.h>
@@ -44,11 +45,16 @@ asmlinkage int sys_pipe(unsigned long r4, unsigned long r5,
return error;
}
-#if defined(HAVE_ARCH_UNMAPPED_AREA) && defined(CONFIG_MMU)
+unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */
+
+EXPORT_SYMBOL(shm_align_mask);
+
/*
- * To avoid cache alias, we map the shard page with same color.
+ * To avoid cache aliases, we map the shared page with same color.
*/
-#define COLOUR_ALIGN(addr) (((addr)+SHMLBA-1)&~(SHMLBA-1))
+#define COLOUR_ALIGN(addr, pgoff) \
+ ((((addr) + shm_align_mask) & ~shm_align_mask) + \
+ (((pgoff) << PAGE_SHIFT) & shm_align_mask))
unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
unsigned long len, unsigned long pgoff, unsigned long flags)
@@ -56,43 +62,52 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
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 & (SHMLBA - 1)))
+ if ((flags & MAP_SHARED) && (addr & shm_align_mask))
return -EINVAL;
return addr;
}
- if (len > TASK_SIZE)
+ if (unlikely(len > TASK_SIZE))
return -ENOMEM;
+ do_colour_align = 0;
+ if (filp || (flags & MAP_SHARED))
+ do_colour_align = 1;
+
if (addr) {
- if (flags & MAP_PRIVATE)
- addr = PAGE_ALIGN(addr);
+ if (do_colour_align)
+ addr = COLOUR_ALIGN(addr, pgoff);
else
- addr = COLOUR_ALIGN(addr);
+ 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) {
+
+ if (len > mm->cached_hole_size) {
+ start_addr = addr = mm->free_area_cache;
+ } else {
mm->cached_hole_size = 0;
- mm->free_area_cache = TASK_UNMAPPED_BASE;
+ start_addr = addr = TASK_UNMAPPED_BASE;
}
- if (flags & MAP_PRIVATE)
- addr = PAGE_ALIGN(mm->free_area_cache);
- else
- addr = COLOUR_ALIGN(mm->free_area_cache);
- start_addr = addr;
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 (TASK_SIZE - len < addr) {
+ if (unlikely(TASK_SIZE - len < addr)) {
/*
* Start a new search - just in case we missed
* some holes.
@@ -104,7 +119,7 @@ full_search:
}
return -ENOMEM;
}
- if (!vma || addr + len <= vma->vm_start) {
+ if (likely(!vma || addr + len <= vma->vm_start)) {
/*
* Remember the place where we stopped the search:
*/
@@ -115,11 +130,10 @@ full_search:
mm->cached_hole_size = vma->vm_start - addr;
addr = vma->vm_end;
- if (!(flags & MAP_PRIVATE))
- addr = COLOUR_ALIGN(addr);
+ if (do_colour_align)
+ addr = COLOUR_ALIGN(addr, pgoff);
}
}
-#endif
static inline long
do_mmap2(unsigned long addr, unsigned long len, unsigned long prot,