WebSVN – Kolibri OS – Blame – /drivers/include/linux/io-mapping.h

Rev	Author	Line No.	Line
7143	serge	1	/*
		2	* Copyright © 2008 Keith Packard
		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
		22	#include
		23	#include
		24	#include
		25	#include
		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
		37
		38	struct io_mapping {
		39	void *vaddr;
		40	resource_size_t base;
		41	unsigned long size;
		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
		56	iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
		57	if (!iomap)
		58	goto out_err;
		59
		60	iomap->vaddr = AllocKernelSpace(4096);
		61	if (iomap->vaddr == NULL)
		62	goto out_free;
		63
		64	iomap->base = base;
		65	iomap->size = size;
		66
		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	FreeKernelSpace(mapping->vaddr);
		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	addr_t phys_addr;
		88
		89	BUG_ON(offset >= mapping->size);
		90	phys_addr = (mapping->base + offset) & PAGE_MASK;
		91
		92	MapPage(mapping->vaddr, phys_addr, PG_WRITEC\|PG_SW);
		93	return mapping->vaddr;
		94	}
		95
		96	static inline void
		97	io_mapping_unmap_atomic(void __iomem *vaddr)
		98	{
		99	MapPage(vaddr, 0, 0);
		100	}
		101
		102	static inline void __iomem *
		103	io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset)
		104	{
		105	addr_t phys_addr;
		106
		107	BUG_ON(offset >= mapping->size);
		108	phys_addr = (mapping->base + offset) & PAGE_MASK;
		109
		110	MapPage(mapping->vaddr, phys_addr, PG_WRITEC\|PG_SW);
		111	return mapping->vaddr;
		112	}
		113
		114	static inline void
		115	io_mapping_unmap(void __iomem *vaddr)
		116	{
		117	MapPage(vaddr, 0, 0);
		118	}
		119
		120	#else
		121
		122	#include
		123
		124	/* this struct isn't actually defined anywhere */
		125	struct io_mapping;
		126
		127	/* Create the io_mapping object*/
		128	static inline struct io_mapping *
		129	io_mapping_create_wc(resource_size_t base, unsigned long size)
		130	{
		131	return (struct io_mapping __force *) ioremap_wc(base, size);
		132	}
		133
		134	static inline void
		135	io_mapping_free(struct io_mapping *mapping)
		136	{
		137	iounmap((void __force __iomem *) mapping);
		138	}
		139
		140	/* Atomic map/unmap */
		141	static inline void __iomem *
		142	io_mapping_map_atomic_wc(struct io_mapping *mapping,
		143	unsigned long offset)
		144	{
		145	preempt_disable();
		146	pagefault_disable();
		147	return ((char __force __iomem *) mapping) + offset;
		148	}
		149
		150	static inline void
		151	io_mapping_unmap_atomic(void __iomem *vaddr)
		152	{
		153	pagefault_enable();
		154	preempt_enable();
		155	}
		156
		157	/* Non-atomic map/unmap */
		158	static inline void __iomem *
		159	io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset)
		160	{
		161	return ((char __force __iomem *) mapping) + offset;
		162	}
		163
		164	static inline void
		165	io_mapping_unmap(void __iomem *vaddr)
		166	{
		167	}
		168
		169	#endif /* HAVE_ATOMIC_IOMAP */
		170
		171	#endif /* _LINUX_IO_MAPPING_H */

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(root)/drivers/include/linux/io-mapping.h – Rev 7143