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![Mauro Carvalho Chehab](/assets/img/avatar_default.png)
Those files got moved, but cross-references still point to the wrong places. Fixes:fcd6807271
("Documentation: Add io-mapping.rst to driver-api manual") Fixes:d1ce350015
("Documentation: Add io_ordering.rst to driver-api manual") Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/c0205119db4fef536272cb0a183b6c14c2c8bf4c.1583927470.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
189 lines
3.7 KiB
C
189 lines
3.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright © 2008 Keith Packard <keithp@keithp.com>
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*/
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#ifndef _LINUX_IO_MAPPING_H
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#define _LINUX_IO_MAPPING_H
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/bug.h>
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#include <linux/io.h>
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#include <asm/page.h>
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/*
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* The io_mapping mechanism provides an abstraction for mapping
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* individual pages from an io device to the CPU in an efficient fashion.
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*
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* See Documentation/driver-api/io-mapping.rst
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*/
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struct io_mapping {
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resource_size_t base;
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unsigned long size;
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pgprot_t prot;
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void __iomem *iomem;
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};
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#ifdef CONFIG_HAVE_ATOMIC_IOMAP
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#include <linux/pfn.h>
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#include <asm/iomap.h>
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/*
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* For small address space machines, mapping large objects
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* into the kernel virtual space isn't practical. Where
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* available, use fixmap support to dynamically map pages
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* of the object at run time.
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*/
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static inline struct io_mapping *
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io_mapping_init_wc(struct io_mapping *iomap,
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resource_size_t base,
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unsigned long size)
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{
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pgprot_t prot;
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if (iomap_create_wc(base, size, &prot))
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return NULL;
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iomap->base = base;
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iomap->size = size;
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iomap->prot = prot;
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return iomap;
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}
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static inline void
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io_mapping_fini(struct io_mapping *mapping)
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{
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iomap_free(mapping->base, mapping->size);
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}
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/* Atomic map/unmap */
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static inline void __iomem *
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io_mapping_map_atomic_wc(struct io_mapping *mapping,
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unsigned long offset)
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{
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resource_size_t phys_addr;
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BUG_ON(offset >= mapping->size);
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phys_addr = mapping->base + offset;
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return iomap_atomic_prot_pfn(PHYS_PFN(phys_addr), mapping->prot);
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}
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static inline void
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io_mapping_unmap_atomic(void __iomem *vaddr)
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{
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iounmap_atomic(vaddr);
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}
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static inline void __iomem *
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io_mapping_map_wc(struct io_mapping *mapping,
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unsigned long offset,
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unsigned long size)
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{
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resource_size_t phys_addr;
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BUG_ON(offset >= mapping->size);
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phys_addr = mapping->base + offset;
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return ioremap_wc(phys_addr, size);
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}
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static inline void
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io_mapping_unmap(void __iomem *vaddr)
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{
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iounmap(vaddr);
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}
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#else
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#include <linux/uaccess.h>
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#include <asm/pgtable.h>
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/* Create the io_mapping object*/
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static inline struct io_mapping *
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io_mapping_init_wc(struct io_mapping *iomap,
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resource_size_t base,
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unsigned long size)
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{
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iomap->base = base;
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iomap->size = size;
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iomap->iomem = ioremap_wc(base, size);
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#if defined(pgprot_noncached_wc) /* archs can't agree on a name ... */
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iomap->prot = pgprot_noncached_wc(PAGE_KERNEL);
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#elif defined(pgprot_writecombine)
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iomap->prot = pgprot_writecombine(PAGE_KERNEL);
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#else
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iomap->prot = pgprot_noncached(PAGE_KERNEL);
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#endif
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return iomap;
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}
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static inline void
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io_mapping_fini(struct io_mapping *mapping)
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{
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iounmap(mapping->iomem);
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}
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/* Non-atomic map/unmap */
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static inline void __iomem *
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io_mapping_map_wc(struct io_mapping *mapping,
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unsigned long offset,
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unsigned long size)
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{
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return mapping->iomem + offset;
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}
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static inline void
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io_mapping_unmap(void __iomem *vaddr)
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{
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}
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/* Atomic map/unmap */
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static inline void __iomem *
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io_mapping_map_atomic_wc(struct io_mapping *mapping,
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unsigned long offset)
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{
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preempt_disable();
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pagefault_disable();
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return io_mapping_map_wc(mapping, offset, PAGE_SIZE);
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}
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static inline void
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io_mapping_unmap_atomic(void __iomem *vaddr)
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{
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io_mapping_unmap(vaddr);
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pagefault_enable();
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preempt_enable();
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}
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#endif /* HAVE_ATOMIC_IOMAP */
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static inline struct io_mapping *
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io_mapping_create_wc(resource_size_t base,
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unsigned long size)
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{
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struct io_mapping *iomap;
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iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
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if (!iomap)
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return NULL;
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if (!io_mapping_init_wc(iomap, base, size)) {
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kfree(iomap);
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return NULL;
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}
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return iomap;
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}
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static inline void
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io_mapping_free(struct io_mapping *iomap)
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{
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io_mapping_fini(iomap);
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kfree(iomap);
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}
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#endif /* _LINUX_IO_MAPPING_H */
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