[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / sh / mm / mmap.c

/*
 * arch/sh/mm/mmap.c
 *
 * Copyright (C) 2008 - 2009  Paul Mundt
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/module.h>
#include <asm/page.h>
#include <asm/processor.h>

unsigned long shm_align_mask = PAGE_SIZE - 1;	/* Sane caches */
EXPORT_SYMBOL(shm_align_mask);

#ifdef CONFIG_MMU
/*
 * To avoid cache aliases, we map the shared page with same color.
 */
static inline unsigned long COLOUR_ALIGN(unsigned long addr,
					 unsigned long pgoff)
{
	unsigned long base = (addr + shm_align_mask) & ~shm_align_mask;
	unsigned long off = (pgoff << PAGE_SHIFT) & shm_align_mask;

	return base + off;
}

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;
	int do_colour_align;
	struct vm_unmapped_area_info info;

	if (flags & MAP_FIXED) {
		/* 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;
	}

	if (unlikely(len > TASK_SIZE))
		return -ENOMEM;

	do_colour_align = 0;
	if (filp || (flags & MAP_SHARED))
		do_colour_align = 1;

	if (addr) {
		if (do_colour_align)
			addr = COLOUR_ALIGN(addr, pgoff);
		else
			addr = PAGE_ALIGN(addr);

		vma = find_vma(mm, addr);
		if (TASK_SIZE - len >= addr &&
		    (!vma || addr + len <= vm_start_gap(vma)))
			return addr;
	}

	info.flags = 0;
	info.length = len;
	info.low_limit = TASK_UNMAPPED_BASE;
	info.high_limit = TASK_SIZE;
	info.align_mask = do_colour_align ? (PAGE_MASK & shm_align_mask) : 0;
	info.align_offset = pgoff << PAGE_SHIFT;
	return vm_unmapped_area(&info);
}

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_colour_align;
	struct vm_unmapped_area_info info;

	if (flags & MAP_FIXED) {
		/* 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;
	}

	if (unlikely(len > TASK_SIZE))
		return -ENOMEM;

	do_colour_align = 0;
	if (filp || (flags & MAP_SHARED))
		do_colour_align = 1;

	/* requesting a specific address */
	if (addr) {
		if (do_colour_align)
			addr = COLOUR_ALIGN(addr, pgoff);
		else
			addr = PAGE_ALIGN(addr);

		vma = find_vma(mm, addr);
		if (TASK_SIZE - len >= addr &&
		    (!vma || addr + len <= vm_start_gap(vma)))
			return addr;
	}

	info.flags = VM_UNMAPPED_AREA_TOPDOWN;
	info.length = len;
	info.low_limit = PAGE_SIZE;
	info.high_limit = mm->mmap_base;
	info.align_mask = do_colour_align ? (PAGE_MASK & shm_align_mask) : 0;
	info.align_offset = pgoff << PAGE_SHIFT;
	addr = vm_unmapped_area(&info);

	/*
	 * 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.
	 */
	if (addr & ~PAGE_MASK) {
		VM_BUG_ON(addr != -ENOMEM);
		info.flags = 0;
		info.low_limit = TASK_UNMAPPED_BASE;
		info.high_limit = TASK_SIZE;
		addr = vm_unmapped_area(&info);
	}

	return addr;
}
#endif /* CONFIG_MMU */

/*
 * You really shouldn't be using read() or write() on /dev/mem.  This
 * might go away in the future.
 */
int valid_phys_addr_range(phys_addr_t addr, size_t count)
{
	if (addr < __MEMORY_START)
		return 0;
	if (addr + count > __pa(high_memory))
		return 0;

	return 1;
}

int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
{
	return 1;
}
Commit	Line	Data
185aed75 PM	1	/*
	2	* arch/sh/mm/mmap.c
	3	*
ee1acbfa	4	* Copyright (C) 2008 - 2009 Paul Mundt
185aed75 PM	5	*
	6	* This file is subject to the terms and conditions of the GNU General Public
	7	* License. See the file "COPYING" in the main directory of this archive
	8	* for more details.
	9	*/
	10	#include <linux/io.h>
	11	#include <linux/mm.h>
4a4a9be3 PM	12	#include <linux/mman.h>
4a4a9be3 PM	13	#include <linux/module.h>
185aed75	14	#include <asm/page.h>
4a4a9be3 PM	15	#include <asm/processor.h>
4a4a9be3 PM	16
4a4a9be3 PM	17	unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */
	18	EXPORT_SYMBOL(shm_align_mask);
	19
dde5e3ff	20	#ifdef CONFIG_MMU
4a4a9be3 PM	21	/*
	22	* To avoid cache aliases, we map the shared page with same color.
	23	*/
ee1acbfa PM	24	static inline unsigned long COLOUR_ALIGN(unsigned long addr,
	25	unsigned long pgoff)
	26	{
	27	unsigned long base = (addr + shm_align_mask) & ~shm_align_mask;
	28	unsigned long off = (pgoff << PAGE_SHIFT) & shm_align_mask;
	29
	30	return base + off;
	31	}
	32
4a4a9be3 PM	33	unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
	34	unsigned long len, unsigned long pgoff, unsigned long flags)
	35	{
	36	struct mm_struct *mm = current->mm;
	37	struct vm_area_struct *vma;
4a4a9be3	38	int do_colour_align;
b4265f12	39	struct vm_unmapped_area_info info;
4a4a9be3 PM	40
	41	if (flags & MAP_FIXED) {
	42	/* We do not accept a shared mapping if it would violate
	43	* cache aliasing constraints.
	44	*/
e77414e0 AV	45	if ((flags & MAP_SHARED) &&
e77414e0 AV	46	((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))
4a4a9be3 PM	47	return -EINVAL;
	48	return addr;
	49	}
	50
	51	if (unlikely(len > TASK_SIZE))
	52	return -ENOMEM;
	53
	54	do_colour_align = 0;
	55	if (filp \|\| (flags & MAP_SHARED))
	56	do_colour_align = 1;
	57
	58	if (addr) {
	59	if (do_colour_align)
	60	addr = COLOUR_ALIGN(addr, pgoff);
	61	else
	62	addr = PAGE_ALIGN(addr);
	63
	64	vma = find_vma(mm, addr);
	65	if (TASK_SIZE - len >= addr &&
1ad9a25d	66	(!vma \|\| addr + len <= vm_start_gap(vma)))
4a4a9be3 PM	67	return addr;
	68	}
	69
b4265f12 ML	70	info.flags = 0;
	71	info.length = len;
	72	info.low_limit = TASK_UNMAPPED_BASE;
	73	info.high_limit = TASK_SIZE;
	74	info.align_mask = do_colour_align ? (PAGE_MASK & shm_align_mask) : 0;
	75	info.align_offset = pgoff << PAGE_SHIFT;
	76	return vm_unmapped_area(&info);
4a4a9be3	77	}
ee1acbfa PM	78
	79	unsigned long
	80	arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
	81	const unsigned long len, const unsigned long pgoff,
	82	const unsigned long flags)
	83	{
	84	struct vm_area_struct *vma;
	85	struct mm_struct *mm = current->mm;
	86	unsigned long addr = addr0;
	87	int do_colour_align;
b4265f12	88	struct vm_unmapped_area_info info;
ee1acbfa PM	89
	90	if (flags & MAP_FIXED) {
	91	/* We do not accept a shared mapping if it would violate
	92	* cache aliasing constraints.
	93	*/
	94	if ((flags & MAP_SHARED) &&
	95	((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))
	96	return -EINVAL;
	97	return addr;
	98	}
	99
	100	if (unlikely(len > TASK_SIZE))
	101	return -ENOMEM;
	102
	103	do_colour_align = 0;
	104	if (filp \|\| (flags & MAP_SHARED))
	105	do_colour_align = 1;
	106
	107	/* requesting a specific address */
	108	if (addr) {
	109	if (do_colour_align)
	110	addr = COLOUR_ALIGN(addr, pgoff);
	111	else
	112	addr = PAGE_ALIGN(addr);
	113
	114	vma = find_vma(mm, addr);
	115	if (TASK_SIZE - len >= addr &&
1ad9a25d	116	(!vma \|\| addr + len <= vm_start_gap(vma)))
ee1acbfa PM	117	return addr;
	118	}
	119
b4265f12 ML	120	info.flags = VM_UNMAPPED_AREA_TOPDOWN;
	121	info.length = len;
	122	info.low_limit = PAGE_SIZE;
	123	info.high_limit = mm->mmap_base;
	124	info.align_mask = do_colour_align ? (PAGE_MASK & shm_align_mask) : 0;
	125	info.align_offset = pgoff << PAGE_SHIFT;
	126	addr = vm_unmapped_area(&info);
ee1acbfa	127
ee1acbfa PM	128	/*
	129	* A failed mmap() very likely causes application failure,
	130	* so fall back to the bottom-up function here. This scenario
	131	* can happen with large stack limits and large mmap()
	132	* allocations.
	133	*/
b4265f12 ML	134	if (addr & ~PAGE_MASK) {
	135	VM_BUG_ON(addr != -ENOMEM);
	136	info.flags = 0;
	137	info.low_limit = TASK_UNMAPPED_BASE;
	138	info.high_limit = TASK_SIZE;
	139	addr = vm_unmapped_area(&info);
	140	}
ee1acbfa PM	141
	142	return addr;
	143	}
4a4a9be3	144	#endif /* CONFIG_MMU */
185aed75 PM	145
	146	/*
	147	* You really shouldn't be using read() or write() on /dev/mem. This
	148	* might go away in the future.
	149	*/
7e6735c3	150	int valid_phys_addr_range(phys_addr_t addr, size_t count)
185aed75	151	{
10840f03	152	if (addr < __MEMORY_START)
185aed75 PM	153	return 0;
	154	if (addr + count > __pa(high_memory))
	155	return 0;
	156
	157	return 1;
	158	}
	159
	160	int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
	161	{
	162	return 1;
	163	}