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sh: Calculate shm alignment at runtime.

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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>
This commit is contained in:
Paul Mundt
2006-09-27 18:36:17 +09:00
parent 87b0ef91b6
commit f3c2575818
7 changed files with 43 additions and 33 deletions
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54
arch/sh/kernel/sys_sh.c
View File

@@ -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,