Commit f3c25758 authored by Paul Mundt's avatar Paul Mundt
Browse files

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: default avatarPaul Mundt <lethal@linux-sh.org>
parent 87b0ef91

arch/sh/kernel/cpu/init.c

+5 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/kernel.h>

#include <asm/processor.h>

#include <asm/uaccess.h>

#include <asm/page.h>

#include <asm/system.h>

#include <asm/cacheflush.h>

#include <asm/cache.h>
@@ -198,6 +199,10 @@ asmlinkage void __init sh_cpu_init(void) 
	/* Init the cache */

	cache_init();



	shm_align_mask = max_t(unsigned long,

			       cpu_data->dcache.way_size - 1,

			       PAGE_SIZE - 1);



	/* Disable the FPU */

	if (fpu_disabled) {

		printk("FPU Disabled\n");

arch/sh/kernel/sys_sh.c

+34 −20
Original line number Diff line number Diff line
@@ -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 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, 
			}

			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 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, 
		        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,

include/asm-sh/cacheflush.h

+2 −0
Original line number Diff line number Diff line
@@ -28,5 +28,7 @@ extern void __flush_invalidate_region(void *start, int size); 
		memcpy(dst, src, len);				\

	} while (0)



#define HAVE_ARCH_UNMAPPED_AREA



#endif /* __KERNEL__ */

#endif /* __ASM_SH_CACHEFLUSH_H */

include/asm-sh/cpu-sh3/cacheflush.h

+0 −8
Original line number Diff line number Diff line
@@ -64,12 +64,4 @@ void flush_icache_page(struct vm_area_struct *vma, struct page *page); 


#define p3_cache_init()				do { } while (0)



/*

 * We provide our own get_unmapped_area to avoid cache aliasing issues

 * on SH7705 with a 32KB cache, and to page align addresses in the

 * non-aliasing case.

 */

#define HAVE_ARCH_UNMAPPED_AREA



#endif /* __ASM_CPU_SH3_CACHEFLUSH_H */

include/asm-sh/cpu-sh4/cacheflush.h

+0 −3
Original line number Diff line number Diff line
@@ -39,9 +39,6 @@ void p3_cache_init(void); 


#define PG_mapped	PG_arch_1



/* We provide our own get_unmapped_area to avoid cache alias issue */

#define HAVE_ARCH_UNMAPPED_AREA



#ifdef CONFIG_MMU

extern int remap_area_pages(unsigned long addr, unsigned long phys_addr,

			    unsigned long size, unsigned long flags);