| /* SPDX-License-Identifier: GPL-2.0-only */ |
| /* |
| * Copyright © 2008 Keith Packard <keithp@keithp.com> |
| */ |
| |
| #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 <linux/pgtable.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/driver-api/io-mapping.rst |
| */ |
| |
| struct io_mapping { |
| resource_size_t base; |
| unsigned long size; |
| pgprot_t prot; |
| void __iomem *iomem; |
| }; |
| |
| #ifdef CONFIG_HAVE_ATOMIC_IOMAP |
| |
| #include <linux/pfn.h> |
| #include <asm/iomap.h> |
| /* |
| * 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_init_wc(struct io_mapping *iomap, |
| resource_size_t base, |
| unsigned long size) |
| { |
| pgprot_t prot; |
| |
| if (iomap_create_wc(base, size, &prot)) |
| return NULL; |
| |
| iomap->base = base; |
| iomap->size = size; |
| iomap->prot = prot; |
| return iomap; |
| } |
| |
| static inline void |
| io_mapping_fini(struct io_mapping *mapping) |
| { |
| iomap_free(mapping->base, mapping->size); |
| } |
| |
| /* Atomic map/unmap */ |
| static inline void __iomem * |
| io_mapping_map_atomic_wc(struct io_mapping *mapping, |
| unsigned long offset) |
| { |
| resource_size_t phys_addr; |
| |
| BUG_ON(offset >= mapping->size); |
| phys_addr = mapping->base + offset; |
| preempt_disable(); |
| pagefault_disable(); |
| return __iomap_local_pfn_prot(PHYS_PFN(phys_addr), mapping->prot); |
| } |
| |
| static inline void |
| io_mapping_unmap_atomic(void __iomem *vaddr) |
| { |
| kunmap_local_indexed((void __force *)vaddr); |
| pagefault_enable(); |
| preempt_enable(); |
| } |
| |
| static inline void __iomem * |
| io_mapping_map_local_wc(struct io_mapping *mapping, unsigned long offset) |
| { |
| resource_size_t phys_addr; |
| |
| BUG_ON(offset >= mapping->size); |
| phys_addr = mapping->base + offset; |
| return __iomap_local_pfn_prot(PHYS_PFN(phys_addr), mapping->prot); |
| } |
| |
| static inline void io_mapping_unmap_local(void __iomem *vaddr) |
| { |
| kunmap_local_indexed((void __force *)vaddr); |
| } |
| |
| static inline void __iomem * |
| io_mapping_map_wc(struct io_mapping *mapping, |
| unsigned long offset, |
| unsigned long size) |
| { |
| resource_size_t phys_addr; |
| |
| BUG_ON(offset >= mapping->size); |
| phys_addr = mapping->base + offset; |
| |
| return ioremap_wc(phys_addr, size); |
| } |
| |
| static inline void |
| io_mapping_unmap(void __iomem *vaddr) |
| { |
| iounmap(vaddr); |
| } |
| |
| #else /* HAVE_ATOMIC_IOMAP */ |
| |
| #include <linux/uaccess.h> |
| |
| /* Create the io_mapping object*/ |
| static inline struct io_mapping * |
| io_mapping_init_wc(struct io_mapping *iomap, |
| resource_size_t base, |
| unsigned long size) |
| { |
| iomap->iomem = ioremap_wc(base, size); |
| if (!iomap->iomem) |
| return NULL; |
| |
| iomap->base = base; |
| iomap->size = size; |
| #if defined(pgprot_noncached_wc) /* archs can't agree on a name ... */ |
| iomap->prot = pgprot_noncached_wc(PAGE_KERNEL); |
| #elif defined(pgprot_writecombine) |
| iomap->prot = pgprot_writecombine(PAGE_KERNEL); |
| #else |
| iomap->prot = pgprot_noncached(PAGE_KERNEL); |
| #endif |
| |
| return iomap; |
| } |
| |
| static inline void |
| io_mapping_fini(struct io_mapping *mapping) |
| { |
| iounmap(mapping->iomem); |
| } |
| |
| /* Non-atomic map/unmap */ |
| static inline void __iomem * |
| io_mapping_map_wc(struct io_mapping *mapping, |
| unsigned long offset, |
| unsigned long size) |
| { |
| return mapping->iomem + offset; |
| } |
| |
| static inline void |
| io_mapping_unmap(void __iomem *vaddr) |
| { |
| } |
| |
| /* Atomic map/unmap */ |
| static inline void __iomem * |
| io_mapping_map_atomic_wc(struct io_mapping *mapping, |
| unsigned long offset) |
| { |
| preempt_disable(); |
| pagefault_disable(); |
| return io_mapping_map_wc(mapping, offset, PAGE_SIZE); |
| } |
| |
| static inline void |
| io_mapping_unmap_atomic(void __iomem *vaddr) |
| { |
| io_mapping_unmap(vaddr); |
| pagefault_enable(); |
| preempt_enable(); |
| } |
| |
| static inline void __iomem * |
| io_mapping_map_local_wc(struct io_mapping *mapping, unsigned long offset) |
| { |
| return io_mapping_map_wc(mapping, offset, PAGE_SIZE); |
| } |
| |
| static inline void io_mapping_unmap_local(void __iomem *vaddr) |
| { |
| io_mapping_unmap(vaddr); |
| } |
| |
| #endif /* !HAVE_ATOMIC_IOMAP */ |
| |
| static inline struct io_mapping * |
| io_mapping_create_wc(resource_size_t base, |
| unsigned long size) |
| { |
| struct io_mapping *iomap; |
| |
| iomap = kmalloc(sizeof(*iomap), GFP_KERNEL); |
| if (!iomap) |
| return NULL; |
| |
| if (!io_mapping_init_wc(iomap, base, size)) { |
| kfree(iomap); |
| return NULL; |
| } |
| |
| return iomap; |
| } |
| |
| static inline void |
| io_mapping_free(struct io_mapping *iomap) |
| { |
| io_mapping_fini(iomap); |
| kfree(iomap); |
| } |
| |
| #endif /* _LINUX_IO_MAPPING_H */ |