[deliverable/linux.git] / include / linux / io-mapping.h

/*
 * Copyright © 2008 Keith Packard <keithp@keithp.com>
 *
 * This file is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#ifndef _LINUX_IO_MAPPING_H
#define _LINUX_IO_MAPPING_H

#include <linux/types.h>
#include <linux/slab.h>
#include <linux/bug.h>
#include <linux/io.h>
#include <asm/page.h>

/*
 * The io_mapping mechanism provides an abstraction for mapping
 * individual pages from an io device to the CPU in an efficient fashion.
 *
 * See Documentation/io-mapping.txt
 */

#ifdef CONFIG_HAVE_ATOMIC_IOMAP

#include <asm/iomap.h>

struct io_mapping {
	resource_size_t base;
	unsigned long size;
	pgprot_t prot;
};

/*
 * For small address space machines, mapping large objects
 * into the kernel virtual space isn't practical. Where
 * available, use fixmap support to dynamically map pages
 * of the object at run time.
 */

static inline struct io_mapping *
io_mapping_create_wc(resource_size_t base, unsigned long size)
{
	struct io_mapping *iomap;
	pgprot_t prot;

	iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
	if (!iomap)
		goto out_err;

	if (iomap_create_wc(base, size, &prot))
		goto out_free;

	iomap->base = base;
	iomap->size = size;
	iomap->prot = prot;
	return iomap;

out_free:
	kfree(iomap);
out_err:
	return NULL;
}

static inline void
io_mapping_free(struct io_mapping *mapping)
{
	iomap_free(mapping->base, mapping->size);
	kfree(mapping);
}

/* Atomic map/unmap */
static inline void __iomem *
io_mapping_map_atomic_wc(struct io_mapping *mapping,
			 unsigned long offset)
{
	resource_size_t phys_addr;
	unsigned long pfn;

	BUG_ON(offset >= mapping->size);
	phys_addr = mapping->base + offset;
	pfn = (unsigned long) (phys_addr >> PAGE_SHIFT);
	return iomap_atomic_prot_pfn(pfn, mapping->prot);
}

static inline void
io_mapping_unmap_atomic(void __iomem *vaddr)
{
	iounmap_atomic(vaddr);
}

static inline void __iomem *
io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset)
{
	resource_size_t phys_addr;

	BUG_ON(offset >= mapping->size);
	phys_addr = mapping->base + offset;

	return ioremap_wc(phys_addr, PAGE_SIZE);
}

static inline void
io_mapping_unmap(void __iomem *vaddr)
{
	iounmap(vaddr);
}

#else

#include <linux/uaccess.h>

/* this struct isn't actually defined anywhere */
struct io_mapping;

/* Create the io_mapping object*/
static inline struct io_mapping *
io_mapping_create_wc(resource_size_t base, unsigned long size)
{
	return (struct io_mapping __force *) ioremap_wc(base, size);
}

static inline void
io_mapping_free(struct io_mapping *mapping)
{
	iounmap((void __force __iomem *) mapping);
}

/* Atomic map/unmap */
static inline void __iomem *
io_mapping_map_atomic_wc(struct io_mapping *mapping,
			 unsigned long offset)
{
	preempt_disable();
	pagefault_disable();
	return ((char __force __iomem *) mapping) + offset;
}

static inline void
io_mapping_unmap_atomic(void __iomem *vaddr)
{
	pagefault_enable();
	preempt_enable();
}

/* Non-atomic map/unmap */
static inline void __iomem *
io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset)
{
	return ((char __force __iomem *) mapping) + offset;
}

static inline void
io_mapping_unmap(void __iomem *vaddr)
{
}

#endif /* HAVE_ATOMIC_IOMAP */

#endif /* _LINUX_IO_MAPPING_H */
Commit	Line	Data
	1	/*
	2	* Copyright © 2008 Keith Packard <keithp@keithp.com>
	3	*
	4	* This file is free software; you can redistribute it and/or modify
	5	* it under the terms of version 2 of the GNU General Public License
	6	* as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	11	* GNU General Public License for more details.
	12	*
	13	* You should have received a copy of the GNU General Public License
	14	* along with this program; if not, write to the Free Software Foundation,
	15	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
	16	*/
	17
	18	#ifndef _LINUX_IO_MAPPING_H
	19	#define _LINUX_IO_MAPPING_H
	20
	21	#include <linux/types.h>
	22	#include <linux/slab.h>
	23	#include <linux/bug.h>
	24	#include <linux/io.h>
	25	#include <asm/page.h>
	26
	27	/*
	28	* The io_mapping mechanism provides an abstraction for mapping
	29	* individual pages from an io device to the CPU in an efficient fashion.
	30	*
	31	* See Documentation/io-mapping.txt
	32	*/
	33
	34	#ifdef CONFIG_HAVE_ATOMIC_IOMAP
	35
	36	#include <asm/iomap.h>
	37
	38	struct io_mapping {
	39	resource_size_t base;
	40	unsigned long size;
	41	pgprot_t prot;
	42	};
	43
	44	/*
	45	* For small address space machines, mapping large objects
	46	* into the kernel virtual space isn't practical. Where
	47	* available, use fixmap support to dynamically map pages
	48	* of the object at run time.
	49	*/
	50
	51	static inline struct io_mapping *
	52	io_mapping_create_wc(resource_size_t base, unsigned long size)
	53	{
	54	struct io_mapping *iomap;
	55	pgprot_t prot;
	56
	57	iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
	58	if (!iomap)
	59	goto out_err;
	60
	61	if (iomap_create_wc(base, size, &prot))
	62	goto out_free;
	63
	64	iomap->base = base;
	65	iomap->size = size;
	66	iomap->prot = prot;
	67	return iomap;
	68
	69	out_free:
	70	kfree(iomap);
	71	out_err:
	72	return NULL;
	73	}
	74
	75	static inline void
	76	io_mapping_free(struct io_mapping *mapping)
	77	{
	78	iomap_free(mapping->base, mapping->size);
	79	kfree(mapping);
	80	}
	81
	82	/* Atomic map/unmap */
	83	static inline void __iomem *
	84	io_mapping_map_atomic_wc(struct io_mapping *mapping,
	85	unsigned long offset)
	86	{
	87	resource_size_t phys_addr;
	88	unsigned long pfn;
	89
	90	BUG_ON(offset >= mapping->size);
	91	phys_addr = mapping->base + offset;
	92	pfn = (unsigned long) (phys_addr >> PAGE_SHIFT);
	93	return iomap_atomic_prot_pfn(pfn, mapping->prot);
	94	}
	95
	96	static inline void
	97	io_mapping_unmap_atomic(void __iomem *vaddr)
	98	{
	99	iounmap_atomic(vaddr);
	100	}
	101
	102	static inline void __iomem *
	103	io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset)
	104	{
	105	resource_size_t phys_addr;
	106
	107	BUG_ON(offset >= mapping->size);
	108	phys_addr = mapping->base + offset;
	109
	110	return ioremap_wc(phys_addr, PAGE_SIZE);
	111	}
	112
	113	static inline void
	114	io_mapping_unmap(void __iomem *vaddr)
	115	{
	116	iounmap(vaddr);
	117	}
	118
	119	#else
	120
	121	#include <linux/uaccess.h>
	122
	123	/* this struct isn't actually defined anywhere */
	124	struct io_mapping;
	125
	126	/* Create the io_mapping object*/
	127	static inline struct io_mapping *
	128	io_mapping_create_wc(resource_size_t base, unsigned long size)
	129	{
	130	return (struct io_mapping __force *) ioremap_wc(base, size);
	131	}
	132
	133	static inline void
	134	io_mapping_free(struct io_mapping *mapping)
	135	{
	136	iounmap((void __force __iomem *) mapping);
	137	}
	138
	139	/* Atomic map/unmap */
	140	static inline void __iomem *
	141	io_mapping_map_atomic_wc(struct io_mapping *mapping,
	142	unsigned long offset)
	143	{
	144	preempt_disable();
	145	pagefault_disable();
	146	return ((char __force __iomem *) mapping) + offset;
	147	}
	148
	149	static inline void
	150	io_mapping_unmap_atomic(void __iomem *vaddr)
	151	{
	152	pagefault_enable();
	153	preempt_enable();
	154	}
	155
	156	/* Non-atomic map/unmap */
	157	static inline void __iomem *
	158	io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset)
	159	{
	160	return ((char __force __iomem *) mapping) + offset;
	161	}
	162
	163	static inline void
	164	io_mapping_unmap(void __iomem *vaddr)
	165	{
	166	}
	167
	168	#endif /* HAVE_ATOMIC_IOMAP */
	169
	170	#endif /* _LINUX_IO_MAPPING_H */