1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright © 2008 Keith Packard <keithp@keithp.com> 4 */ 5 6 #ifndef _LINUX_IO_MAPPING_H 7 #define _LINUX_IO_MAPPING_H 8 9 #include <linux/types.h> 10 #include <linux/slab.h> 11 #include <linux/bug.h> 12 #include <linux/io.h> 13 #include <linux/pgtable.h> 14 #include <asm/page.h> 15 16 /* 17 * The io_mapping mechanism provides an abstraction for mapping 18 * individual pages from an io device to the CPU in an efficient fashion. 19 * 20 * See Documentation/driver-api/io-mapping.rst 21 */ 22 23 struct io_mapping { 24 resource_size_t base; 25 unsigned long size; 26 pgprot_t prot; 27 void __iomem *iomem; 28 }; 29 30 #ifdef CONFIG_HAVE_ATOMIC_IOMAP 31 32 #include <linux/pfn.h> 33 #include <asm/iomap.h> 34 /* 35 * For small address space machines, mapping large objects 36 * into the kernel virtual space isn't practical. Where 37 * available, use fixmap support to dynamically map pages 38 * of the object at run time. 39 */ 40 41 static inline struct io_mapping * 42 io_mapping_init_wc(struct io_mapping *iomap, 43 resource_size_t base, 44 unsigned long size) 45 { 46 pgprot_t prot; 47 48 if (iomap_create_wc(base, size, &prot)) 49 return NULL; 50 51 iomap->base = base; 52 iomap->size = size; 53 iomap->prot = prot; 54 return iomap; 55 } 56 57 static inline void 58 io_mapping_fini(struct io_mapping *mapping) 59 { 60 iomap_free(mapping->base, mapping->size); 61 } 62 63 /* Atomic map/unmap */ 64 static inline void __iomem * 65 io_mapping_map_atomic_wc(struct io_mapping *mapping, 66 unsigned long offset) 67 { 68 resource_size_t phys_addr; 69 70 BUG_ON(offset >= mapping->size); 71 phys_addr = mapping->base + offset; 72 preempt_disable(); 73 pagefault_disable(); 74 return __iomap_local_pfn_prot(PHYS_PFN(phys_addr), mapping->prot); 75 } 76 77 static inline void 78 io_mapping_unmap_atomic(void __iomem *vaddr) 79 { 80 kunmap_local_indexed((void __force *)vaddr); 81 pagefault_enable(); 82 preempt_enable(); 83 } 84 85 static inline void __iomem * 86 io_mapping_map_local_wc(struct io_mapping *mapping, unsigned long offset) 87 { 88 resource_size_t phys_addr; 89 90 BUG_ON(offset >= mapping->size); 91 phys_addr = mapping->base + offset; 92 return __iomap_local_pfn_prot(PHYS_PFN(phys_addr), mapping->prot); 93 } 94 95 static inline void io_mapping_unmap_local(void __iomem *vaddr) 96 { 97 kunmap_local_indexed((void __force *)vaddr); 98 } 99 100 static inline void __iomem * 101 io_mapping_map_wc(struct io_mapping *mapping, 102 unsigned long offset, 103 unsigned long size) 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, size); 111 } 112 113 static inline void 114 io_mapping_unmap(void __iomem *vaddr) 115 { 116 iounmap(vaddr); 117 } 118 119 #else /* HAVE_ATOMIC_IOMAP */ 120 121 #include <linux/uaccess.h> 122 123 /* Create the io_mapping object*/ 124 static inline struct io_mapping * 125 io_mapping_init_wc(struct io_mapping *iomap, 126 resource_size_t base, 127 unsigned long size) 128 { 129 iomap->iomem = ioremap_wc(base, size); 130 if (!iomap->iomem) 131 return NULL; 132 133 iomap->base = base; 134 iomap->size = size; 135 iomap->prot = pgprot_writecombine(PAGE_KERNEL); 136 137 return iomap; 138 } 139 140 static inline void 141 io_mapping_fini(struct io_mapping *mapping) 142 { 143 iounmap(mapping->iomem); 144 } 145 146 /* Non-atomic map/unmap */ 147 static inline void __iomem * 148 io_mapping_map_wc(struct io_mapping *mapping, 149 unsigned long offset, 150 unsigned long size) 151 { 152 return mapping->iomem + offset; 153 } 154 155 static inline void 156 io_mapping_unmap(void __iomem *vaddr) 157 { 158 } 159 160 /* Atomic map/unmap */ 161 static inline void __iomem * 162 io_mapping_map_atomic_wc(struct io_mapping *mapping, 163 unsigned long offset) 164 { 165 preempt_disable(); 166 pagefault_disable(); 167 return io_mapping_map_wc(mapping, offset, PAGE_SIZE); 168 } 169 170 static inline void 171 io_mapping_unmap_atomic(void __iomem *vaddr) 172 { 173 io_mapping_unmap(vaddr); 174 pagefault_enable(); 175 preempt_enable(); 176 } 177 178 static inline void __iomem * 179 io_mapping_map_local_wc(struct io_mapping *mapping, unsigned long offset) 180 { 181 return io_mapping_map_wc(mapping, offset, PAGE_SIZE); 182 } 183 184 static inline void io_mapping_unmap_local(void __iomem *vaddr) 185 { 186 io_mapping_unmap(vaddr); 187 } 188 189 #endif /* !HAVE_ATOMIC_IOMAP */ 190 191 static inline struct io_mapping * 192 io_mapping_create_wc(resource_size_t base, 193 unsigned long size) 194 { 195 struct io_mapping *iomap; 196 197 iomap = kmalloc(sizeof(*iomap), GFP_KERNEL); 198 if (!iomap) 199 return NULL; 200 201 if (!io_mapping_init_wc(iomap, base, size)) { 202 kfree(iomap); 203 return NULL; 204 } 205 206 return iomap; 207 } 208 209 static inline void 210 io_mapping_free(struct io_mapping *iomap) 211 { 212 io_mapping_fini(iomap); 213 kfree(iomap); 214 } 215 216 #endif /* _LINUX_IO_MAPPING_H */ 217 218 int io_mapping_map_user(struct io_mapping *iomap, struct vm_area_struct *vma, 219 unsigned long addr, unsigned long pfn, unsigned long size); 220