Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/arch/arm/mm/consistent.c |
| 3 | * |
| 4 | * Copyright (C) 2000-2004 Russell King |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | * |
| 10 | * DMA uncached mapping support. |
| 11 | */ |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/mm.h> |
| 14 | #include <linux/slab.h> |
| 15 | #include <linux/errno.h> |
| 16 | #include <linux/list.h> |
| 17 | #include <linux/init.h> |
| 18 | #include <linux/device.h> |
| 19 | #include <linux/dma-mapping.h> |
| 20 | |
| 21 | #include <asm/cacheflush.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include <asm/tlbflush.h> |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 23 | #include <asm/sizes.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 25 | /* Sanity check size */ |
| 26 | #if (CONSISTENT_DMA_SIZE % SZ_2M) |
| 27 | #error "CONSISTENT_DMA_SIZE must be multiple of 2MiB" |
| 28 | #endif |
| 29 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | #define CONSISTENT_END (0xffe00000) |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 31 | #define CONSISTENT_BASE (CONSISTENT_END - CONSISTENT_DMA_SIZE) |
| 32 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | #define CONSISTENT_OFFSET(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT) |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 34 | #define CONSISTENT_PTE_INDEX(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PGDIR_SHIFT) |
| 35 | #define NUM_CONSISTENT_PTES (CONSISTENT_DMA_SIZE >> PGDIR_SHIFT) |
| 36 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | |
| 38 | /* |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 39 | * These are the page tables (2MB each) covering uncached, DMA consistent allocations |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | */ |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 41 | static pte_t *consistent_pte[NUM_CONSISTENT_PTES]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | static DEFINE_SPINLOCK(consistent_lock); |
| 43 | |
| 44 | /* |
| 45 | * VM region handling support. |
| 46 | * |
| 47 | * This should become something generic, handling VM region allocations for |
| 48 | * vmalloc and similar (ioremap, module space, etc). |
| 49 | * |
| 50 | * I envisage vmalloc()'s supporting vm_struct becoming: |
| 51 | * |
| 52 | * struct vm_struct { |
| 53 | * struct vm_region region; |
| 54 | * unsigned long flags; |
| 55 | * struct page **pages; |
| 56 | * unsigned int nr_pages; |
| 57 | * unsigned long phys_addr; |
| 58 | * }; |
| 59 | * |
| 60 | * get_vm_area() would then call vm_region_alloc with an appropriate |
| 61 | * struct vm_region head (eg): |
| 62 | * |
| 63 | * struct vm_region vmalloc_head = { |
| 64 | * .vm_list = LIST_HEAD_INIT(vmalloc_head.vm_list), |
| 65 | * .vm_start = VMALLOC_START, |
| 66 | * .vm_end = VMALLOC_END, |
| 67 | * }; |
| 68 | * |
| 69 | * However, vmalloc_head.vm_start is variable (typically, it is dependent on |
| 70 | * the amount of RAM found at boot time.) I would imagine that get_vm_area() |
| 71 | * would have to initialise this each time prior to calling vm_region_alloc(). |
| 72 | */ |
| 73 | struct vm_region { |
| 74 | struct list_head vm_list; |
| 75 | unsigned long vm_start; |
| 76 | unsigned long vm_end; |
| 77 | struct page *vm_pages; |
Russell King | 5edf71a | 2005-11-25 15:52:51 +0000 | [diff] [blame] | 78 | int vm_active; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | }; |
| 80 | |
| 81 | static struct vm_region consistent_head = { |
| 82 | .vm_list = LIST_HEAD_INIT(consistent_head.vm_list), |
| 83 | .vm_start = CONSISTENT_BASE, |
| 84 | .vm_end = CONSISTENT_END, |
| 85 | }; |
| 86 | |
| 87 | static struct vm_region * |
Al Viro | f9e3214 | 2005-10-21 03:20:58 -0400 | [diff] [blame] | 88 | vm_region_alloc(struct vm_region *head, size_t size, gfp_t gfp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | { |
| 90 | unsigned long addr = head->vm_start, end = head->vm_end - size; |
| 91 | unsigned long flags; |
| 92 | struct vm_region *c, *new; |
| 93 | |
| 94 | new = kmalloc(sizeof(struct vm_region), gfp); |
| 95 | if (!new) |
| 96 | goto out; |
| 97 | |
| 98 | spin_lock_irqsave(&consistent_lock, flags); |
| 99 | |
| 100 | list_for_each_entry(c, &head->vm_list, vm_list) { |
| 101 | if ((addr + size) < addr) |
| 102 | goto nospc; |
| 103 | if ((addr + size) <= c->vm_start) |
| 104 | goto found; |
| 105 | addr = c->vm_end; |
| 106 | if (addr > end) |
| 107 | goto nospc; |
| 108 | } |
| 109 | |
| 110 | found: |
| 111 | /* |
| 112 | * Insert this entry _before_ the one we found. |
| 113 | */ |
| 114 | list_add_tail(&new->vm_list, &c->vm_list); |
| 115 | new->vm_start = addr; |
| 116 | new->vm_end = addr + size; |
Russell King | 5edf71a | 2005-11-25 15:52:51 +0000 | [diff] [blame] | 117 | new->vm_active = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | |
| 119 | spin_unlock_irqrestore(&consistent_lock, flags); |
| 120 | return new; |
| 121 | |
| 122 | nospc: |
| 123 | spin_unlock_irqrestore(&consistent_lock, flags); |
| 124 | kfree(new); |
| 125 | out: |
| 126 | return NULL; |
| 127 | } |
| 128 | |
| 129 | static struct vm_region *vm_region_find(struct vm_region *head, unsigned long addr) |
| 130 | { |
| 131 | struct vm_region *c; |
| 132 | |
| 133 | list_for_each_entry(c, &head->vm_list, vm_list) { |
Russell King | 5edf71a | 2005-11-25 15:52:51 +0000 | [diff] [blame] | 134 | if (c->vm_active && c->vm_start == addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | goto out; |
| 136 | } |
| 137 | c = NULL; |
| 138 | out: |
| 139 | return c; |
| 140 | } |
| 141 | |
| 142 | #ifdef CONFIG_HUGETLB_PAGE |
| 143 | #error ARM Coherent DMA allocator does not (yet) support huge TLB |
| 144 | #endif |
| 145 | |
| 146 | static void * |
Al Viro | f9e3214 | 2005-10-21 03:20:58 -0400 | [diff] [blame] | 147 | __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | pgprot_t prot) |
| 149 | { |
| 150 | struct page *page; |
| 151 | struct vm_region *c; |
| 152 | unsigned long order; |
| 153 | u64 mask = ISA_DMA_THRESHOLD, limit; |
| 154 | |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 155 | if (!consistent_pte[0]) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | printk(KERN_ERR "%s: not initialised\n", __func__); |
| 157 | dump_stack(); |
| 158 | return NULL; |
| 159 | } |
| 160 | |
| 161 | if (dev) { |
| 162 | mask = dev->coherent_dma_mask; |
| 163 | |
| 164 | /* |
| 165 | * Sanity check the DMA mask - it must be non-zero, and |
| 166 | * must be able to be satisfied by a DMA allocation. |
| 167 | */ |
| 168 | if (mask == 0) { |
| 169 | dev_warn(dev, "coherent DMA mask is unset\n"); |
| 170 | goto no_page; |
| 171 | } |
| 172 | |
| 173 | if ((~mask) & ISA_DMA_THRESHOLD) { |
| 174 | dev_warn(dev, "coherent DMA mask %#llx is smaller " |
| 175 | "than system GFP_DMA mask %#llx\n", |
| 176 | mask, (unsigned long long)ISA_DMA_THRESHOLD); |
| 177 | goto no_page; |
| 178 | } |
| 179 | } |
| 180 | |
| 181 | /* |
| 182 | * Sanity check the allocation size. |
| 183 | */ |
| 184 | size = PAGE_ALIGN(size); |
| 185 | limit = (mask + 1) & ~mask; |
| 186 | if ((limit && size >= limit) || |
| 187 | size >= (CONSISTENT_END - CONSISTENT_BASE)) { |
| 188 | printk(KERN_WARNING "coherent allocation too big " |
| 189 | "(requested %#x mask %#llx)\n", size, mask); |
| 190 | goto no_page; |
| 191 | } |
| 192 | |
| 193 | order = get_order(size); |
| 194 | |
| 195 | if (mask != 0xffffffff) |
| 196 | gfp |= GFP_DMA; |
| 197 | |
| 198 | page = alloc_pages(gfp, order); |
| 199 | if (!page) |
| 200 | goto no_page; |
| 201 | |
| 202 | /* |
| 203 | * Invalidate any data that might be lurking in the |
| 204 | * kernel direct-mapped region for device DMA. |
| 205 | */ |
| 206 | { |
| 207 | unsigned long kaddr = (unsigned long)page_address(page); |
| 208 | memset(page_address(page), 0, size); |
| 209 | dmac_flush_range(kaddr, kaddr + size); |
| 210 | } |
| 211 | |
| 212 | /* |
| 213 | * Allocate a virtual address in the consistent mapping region. |
| 214 | */ |
| 215 | c = vm_region_alloc(&consistent_head, size, |
| 216 | gfp & ~(__GFP_DMA | __GFP_HIGHMEM)); |
| 217 | if (c) { |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 218 | pte_t *pte; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 219 | struct page *end = page + (1 << order); |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 220 | int idx = CONSISTENT_PTE_INDEX(c->vm_start); |
| 221 | u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 223 | pte = consistent_pte[idx] + off; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | c->vm_pages = page; |
| 225 | |
| 226 | /* |
| 227 | * Set the "dma handle" |
| 228 | */ |
| 229 | *handle = page_to_dma(dev, page); |
| 230 | |
| 231 | do { |
| 232 | BUG_ON(!pte_none(*pte)); |
| 233 | |
| 234 | set_page_count(page, 1); |
| 235 | /* |
| 236 | * x86 does not mark the pages reserved... |
| 237 | */ |
| 238 | SetPageReserved(page); |
| 239 | set_pte(pte, mk_pte(page, prot)); |
| 240 | page++; |
| 241 | pte++; |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 242 | off++; |
| 243 | if (off >= PTRS_PER_PTE) { |
| 244 | off = 0; |
| 245 | pte = consistent_pte[++idx]; |
| 246 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 247 | } while (size -= PAGE_SIZE); |
| 248 | |
| 249 | /* |
| 250 | * Free the otherwise unused pages. |
| 251 | */ |
| 252 | while (page < end) { |
| 253 | set_page_count(page, 1); |
| 254 | __free_page(page); |
| 255 | page++; |
| 256 | } |
| 257 | |
| 258 | return (void *)c->vm_start; |
| 259 | } |
| 260 | |
| 261 | if (page) |
| 262 | __free_pages(page, order); |
| 263 | no_page: |
| 264 | *handle = ~0; |
| 265 | return NULL; |
| 266 | } |
| 267 | |
| 268 | /* |
| 269 | * Allocate DMA-coherent memory space and return both the kernel remapped |
| 270 | * virtual and bus address for that space. |
| 271 | */ |
| 272 | void * |
Al Viro | f9e3214 | 2005-10-21 03:20:58 -0400 | [diff] [blame] | 273 | dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | { |
| 275 | return __dma_alloc(dev, size, handle, gfp, |
| 276 | pgprot_noncached(pgprot_kernel)); |
| 277 | } |
| 278 | EXPORT_SYMBOL(dma_alloc_coherent); |
| 279 | |
| 280 | /* |
| 281 | * Allocate a writecombining region, in much the same way as |
| 282 | * dma_alloc_coherent above. |
| 283 | */ |
| 284 | void * |
Al Viro | f9e3214 | 2005-10-21 03:20:58 -0400 | [diff] [blame] | 285 | dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 286 | { |
| 287 | return __dma_alloc(dev, size, handle, gfp, |
| 288 | pgprot_writecombine(pgprot_kernel)); |
| 289 | } |
| 290 | EXPORT_SYMBOL(dma_alloc_writecombine); |
| 291 | |
| 292 | static int dma_mmap(struct device *dev, struct vm_area_struct *vma, |
| 293 | void *cpu_addr, dma_addr_t dma_addr, size_t size) |
| 294 | { |
| 295 | unsigned long flags, user_size, kern_size; |
| 296 | struct vm_region *c; |
| 297 | int ret = -ENXIO; |
| 298 | |
| 299 | user_size = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; |
| 300 | |
| 301 | spin_lock_irqsave(&consistent_lock, flags); |
| 302 | c = vm_region_find(&consistent_head, (unsigned long)cpu_addr); |
| 303 | spin_unlock_irqrestore(&consistent_lock, flags); |
| 304 | |
| 305 | if (c) { |
| 306 | unsigned long off = vma->vm_pgoff; |
| 307 | |
| 308 | kern_size = (c->vm_end - c->vm_start) >> PAGE_SHIFT; |
| 309 | |
| 310 | if (off < kern_size && |
| 311 | user_size <= (kern_size - off)) { |
| 312 | vma->vm_flags |= VM_RESERVED; |
| 313 | ret = remap_pfn_range(vma, vma->vm_start, |
| 314 | page_to_pfn(c->vm_pages) + off, |
| 315 | user_size << PAGE_SHIFT, |
| 316 | vma->vm_page_prot); |
| 317 | } |
| 318 | } |
| 319 | |
| 320 | return ret; |
| 321 | } |
| 322 | |
| 323 | int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma, |
| 324 | void *cpu_addr, dma_addr_t dma_addr, size_t size) |
| 325 | { |
| 326 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
| 327 | return dma_mmap(dev, vma, cpu_addr, dma_addr, size); |
| 328 | } |
| 329 | EXPORT_SYMBOL(dma_mmap_coherent); |
| 330 | |
| 331 | int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma, |
| 332 | void *cpu_addr, dma_addr_t dma_addr, size_t size) |
| 333 | { |
| 334 | vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); |
| 335 | return dma_mmap(dev, vma, cpu_addr, dma_addr, size); |
| 336 | } |
| 337 | EXPORT_SYMBOL(dma_mmap_writecombine); |
| 338 | |
| 339 | /* |
| 340 | * free a page as defined by the above mapping. |
Russell King | 5edf71a | 2005-11-25 15:52:51 +0000 | [diff] [blame] | 341 | * Must not be called with IRQs disabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 342 | */ |
| 343 | void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle) |
| 344 | { |
| 345 | struct vm_region *c; |
| 346 | unsigned long flags, addr; |
| 347 | pte_t *ptep; |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 348 | int idx; |
| 349 | u32 off; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | |
Russell King | 5edf71a | 2005-11-25 15:52:51 +0000 | [diff] [blame] | 351 | WARN_ON(irqs_disabled()); |
| 352 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 353 | size = PAGE_ALIGN(size); |
| 354 | |
| 355 | spin_lock_irqsave(&consistent_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | c = vm_region_find(&consistent_head, (unsigned long)cpu_addr); |
| 357 | if (!c) |
| 358 | goto no_area; |
| 359 | |
Russell King | 5edf71a | 2005-11-25 15:52:51 +0000 | [diff] [blame] | 360 | c->vm_active = 0; |
| 361 | spin_unlock_irqrestore(&consistent_lock, flags); |
| 362 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | if ((c->vm_end - c->vm_start) != size) { |
| 364 | printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n", |
| 365 | __func__, c->vm_end - c->vm_start, size); |
| 366 | dump_stack(); |
| 367 | size = c->vm_end - c->vm_start; |
| 368 | } |
| 369 | |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 370 | idx = CONSISTENT_PTE_INDEX(c->vm_start); |
| 371 | off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1); |
| 372 | ptep = consistent_pte[idx] + off; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 373 | addr = c->vm_start; |
| 374 | do { |
| 375 | pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep); |
| 376 | unsigned long pfn; |
| 377 | |
| 378 | ptep++; |
| 379 | addr += PAGE_SIZE; |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 380 | off++; |
| 381 | if (off >= PTRS_PER_PTE) { |
| 382 | off = 0; |
| 383 | ptep = consistent_pte[++idx]; |
| 384 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 385 | |
| 386 | if (!pte_none(pte) && pte_present(pte)) { |
| 387 | pfn = pte_pfn(pte); |
| 388 | |
| 389 | if (pfn_valid(pfn)) { |
| 390 | struct page *page = pfn_to_page(pfn); |
| 391 | |
| 392 | /* |
| 393 | * x86 does not mark the pages reserved... |
| 394 | */ |
| 395 | ClearPageReserved(page); |
| 396 | |
| 397 | __free_page(page); |
| 398 | continue; |
| 399 | } |
| 400 | } |
| 401 | |
| 402 | printk(KERN_CRIT "%s: bad page in kernel page table\n", |
| 403 | __func__); |
| 404 | } while (size -= PAGE_SIZE); |
| 405 | |
| 406 | flush_tlb_kernel_range(c->vm_start, c->vm_end); |
| 407 | |
Russell King | 5edf71a | 2005-11-25 15:52:51 +0000 | [diff] [blame] | 408 | spin_lock_irqsave(&consistent_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | list_del(&c->vm_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 410 | spin_unlock_irqrestore(&consistent_lock, flags); |
| 411 | |
| 412 | kfree(c); |
| 413 | return; |
| 414 | |
| 415 | no_area: |
| 416 | spin_unlock_irqrestore(&consistent_lock, flags); |
| 417 | printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n", |
| 418 | __func__, cpu_addr); |
| 419 | dump_stack(); |
| 420 | } |
| 421 | EXPORT_SYMBOL(dma_free_coherent); |
| 422 | |
| 423 | /* |
| 424 | * Initialise the consistent memory allocation. |
| 425 | */ |
| 426 | static int __init consistent_init(void) |
| 427 | { |
| 428 | pgd_t *pgd; |
| 429 | pmd_t *pmd; |
| 430 | pte_t *pte; |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 431 | int ret = 0, i = 0; |
| 432 | u32 base = CONSISTENT_BASE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | do { |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 435 | pgd = pgd_offset(&init_mm, base); |
| 436 | pmd = pmd_alloc(&init_mm, pgd, base); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 437 | if (!pmd) { |
| 438 | printk(KERN_ERR "%s: no pmd tables\n", __func__); |
| 439 | ret = -ENOMEM; |
| 440 | break; |
| 441 | } |
| 442 | WARN_ON(!pmd_none(*pmd)); |
| 443 | |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 444 | pte = pte_alloc_kernel(pmd, base); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 445 | if (!pte) { |
| 446 | printk(KERN_ERR "%s: no pte tables\n", __func__); |
| 447 | ret = -ENOMEM; |
| 448 | break; |
| 449 | } |
| 450 | |
Kevin Hilman | 37134cd | 2006-01-12 16:12:21 +0000 | [diff] [blame] | 451 | consistent_pte[i++] = pte; |
| 452 | base += (1 << PGDIR_SHIFT); |
| 453 | } while (base < CONSISTENT_END); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | return ret; |
| 456 | } |
| 457 | |
| 458 | core_initcall(consistent_init); |
| 459 | |
| 460 | /* |
| 461 | * Make an area consistent for devices. |
| 462 | */ |
| 463 | void consistent_sync(void *vaddr, size_t size, int direction) |
| 464 | { |
| 465 | unsigned long start = (unsigned long)vaddr; |
| 466 | unsigned long end = start + size; |
| 467 | |
| 468 | switch (direction) { |
| 469 | case DMA_FROM_DEVICE: /* invalidate only */ |
| 470 | dmac_inv_range(start, end); |
| 471 | break; |
| 472 | case DMA_TO_DEVICE: /* writeback only */ |
| 473 | dmac_clean_range(start, end); |
| 474 | break; |
| 475 | case DMA_BIDIRECTIONAL: /* writeback and invalidate */ |
| 476 | dmac_flush_range(start, end); |
| 477 | break; |
| 478 | default: |
| 479 | BUG(); |
| 480 | } |
| 481 | } |
| 482 | EXPORT_SYMBOL(consistent_sync); |