1 /* 2 * arch/powerpc/sysdev/dart_iommu.c 3 * 4 * Copyright (C) 2004 Olof Johansson <olof@lixom.net>, IBM Corporation 5 * Copyright (C) 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>, 6 * IBM Corporation 7 * 8 * Based on pSeries_iommu.c: 9 * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation 10 * Copyright (C) 2004 Olof Johansson <olof@lixom.net>, IBM Corporation 11 * 12 * Dynamic DMA mapping support, Apple U3, U4 & IBM CPC925 "DART" iommu. 13 * 14 * 15 * This program is free software; you can redistribute it and/or modify 16 * it under the terms of the GNU General Public License as published by 17 * the Free Software Foundation; either version 2 of the License, or 18 * (at your option) any later version. 19 * 20 * This program is distributed in the hope that it will be useful, 21 * but WITHOUT ANY WARRANTY; without even the implied warranty of 22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 23 * GNU General Public License for more details. 24 * 25 * You should have received a copy of the GNU General Public License 26 * along with this program; if not, write to the Free Software 27 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 28 */ 29 30 #include <linux/init.h> 31 #include <linux/types.h> 32 #include <linux/slab.h> 33 #include <linux/mm.h> 34 #include <linux/spinlock.h> 35 #include <linux/string.h> 36 #include <linux/pci.h> 37 #include <linux/dma-mapping.h> 38 #include <linux/vmalloc.h> 39 #include <linux/suspend.h> 40 #include <asm/io.h> 41 #include <asm/prom.h> 42 #include <asm/iommu.h> 43 #include <asm/pci-bridge.h> 44 #include <asm/machdep.h> 45 #include <asm/abs_addr.h> 46 #include <asm/cacheflush.h> 47 #include <asm/lmb.h> 48 #include <asm/ppc-pci.h> 49 50 #include "dart.h" 51 52 /* Physical base address and size of the DART table */ 53 unsigned long dart_tablebase; /* exported to htab_initialize */ 54 static unsigned long dart_tablesize; 55 56 /* Virtual base address of the DART table */ 57 static u32 *dart_vbase; 58 #ifdef CONFIG_PM 59 static u32 *dart_copy; 60 #endif 61 62 /* Mapped base address for the dart */ 63 static unsigned int __iomem *dart; 64 65 /* Dummy val that entries are set to when unused */ 66 static unsigned int dart_emptyval; 67 68 static struct iommu_table iommu_table_dart; 69 static int iommu_table_dart_inited; 70 static int dart_dirty; 71 static int dart_is_u4; 72 73 #define DBG(...) 74 75 static inline void dart_tlb_invalidate_all(void) 76 { 77 unsigned long l = 0; 78 unsigned int reg, inv_bit; 79 unsigned long limit; 80 81 DBG("dart: flush\n"); 82 83 /* To invalidate the DART, set the DARTCNTL_FLUSHTLB bit in the 84 * control register and wait for it to clear. 85 * 86 * Gotcha: Sometimes, the DART won't detect that the bit gets 87 * set. If so, clear it and set it again. 88 */ 89 90 limit = 0; 91 92 inv_bit = dart_is_u4 ? DART_CNTL_U4_FLUSHTLB : DART_CNTL_U3_FLUSHTLB; 93 retry: 94 l = 0; 95 reg = DART_IN(DART_CNTL); 96 reg |= inv_bit; 97 DART_OUT(DART_CNTL, reg); 98 99 while ((DART_IN(DART_CNTL) & inv_bit) && l < (1L << limit)) 100 l++; 101 if (l == (1L << limit)) { 102 if (limit < 4) { 103 limit++; 104 reg = DART_IN(DART_CNTL); 105 reg &= ~inv_bit; 106 DART_OUT(DART_CNTL, reg); 107 goto retry; 108 } else 109 panic("DART: TLB did not flush after waiting a long " 110 "time. Buggy U3 ?"); 111 } 112 } 113 114 static inline void dart_tlb_invalidate_one(unsigned long bus_rpn) 115 { 116 unsigned int reg; 117 unsigned int l, limit; 118 119 reg = DART_CNTL_U4_ENABLE | DART_CNTL_U4_IONE | 120 (bus_rpn & DART_CNTL_U4_IONE_MASK); 121 DART_OUT(DART_CNTL, reg); 122 123 limit = 0; 124 wait_more: 125 l = 0; 126 while ((DART_IN(DART_CNTL) & DART_CNTL_U4_IONE) && l < (1L << limit)) { 127 rmb(); 128 l++; 129 } 130 131 if (l == (1L << limit)) { 132 if (limit < 4) { 133 limit++; 134 goto wait_more; 135 } else 136 panic("DART: TLB did not flush after waiting a long " 137 "time. Buggy U4 ?"); 138 } 139 } 140 141 static void dart_flush(struct iommu_table *tbl) 142 { 143 mb(); 144 if (dart_dirty) { 145 dart_tlb_invalidate_all(); 146 dart_dirty = 0; 147 } 148 } 149 150 static void dart_build(struct iommu_table *tbl, long index, 151 long npages, unsigned long uaddr, 152 enum dma_data_direction direction) 153 { 154 unsigned int *dp; 155 unsigned int rpn; 156 long l; 157 158 DBG("dart: build at: %lx, %lx, addr: %x\n", index, npages, uaddr); 159 160 dp = ((unsigned int*)tbl->it_base) + index; 161 162 /* On U3, all memory is contigous, so we can move this 163 * out of the loop. 164 */ 165 l = npages; 166 while (l--) { 167 rpn = virt_to_abs(uaddr) >> DART_PAGE_SHIFT; 168 169 *(dp++) = DARTMAP_VALID | (rpn & DARTMAP_RPNMASK); 170 171 uaddr += DART_PAGE_SIZE; 172 } 173 174 /* make sure all updates have reached memory */ 175 mb(); 176 in_be32((unsigned __iomem *)dp); 177 mb(); 178 179 if (dart_is_u4) { 180 rpn = index; 181 while (npages--) 182 dart_tlb_invalidate_one(rpn++); 183 } else { 184 dart_dirty = 1; 185 } 186 } 187 188 189 static void dart_free(struct iommu_table *tbl, long index, long npages) 190 { 191 unsigned int *dp; 192 193 /* We don't worry about flushing the TLB cache. The only drawback of 194 * not doing it is that we won't catch buggy device drivers doing 195 * bad DMAs, but then no 32-bit architecture ever does either. 196 */ 197 198 DBG("dart: free at: %lx, %lx\n", index, npages); 199 200 dp = ((unsigned int *)tbl->it_base) + index; 201 202 while (npages--) 203 *(dp++) = dart_emptyval; 204 } 205 206 207 static int dart_init(struct device_node *dart_node) 208 { 209 unsigned int i; 210 unsigned long tmp, base, size; 211 struct resource r; 212 213 if (dart_tablebase == 0 || dart_tablesize == 0) { 214 printk(KERN_INFO "DART: table not allocated, using " 215 "direct DMA\n"); 216 return -ENODEV; 217 } 218 219 if (of_address_to_resource(dart_node, 0, &r)) 220 panic("DART: can't get register base ! "); 221 222 /* Make sure nothing from the DART range remains in the CPU cache 223 * from a previous mapping that existed before the kernel took 224 * over 225 */ 226 flush_dcache_phys_range(dart_tablebase, 227 dart_tablebase + dart_tablesize); 228 229 /* Allocate a spare page to map all invalid DART pages. We need to do 230 * that to work around what looks like a problem with the HT bridge 231 * prefetching into invalid pages and corrupting data 232 */ 233 tmp = lmb_alloc(DART_PAGE_SIZE, DART_PAGE_SIZE); 234 dart_emptyval = DARTMAP_VALID | ((tmp >> DART_PAGE_SHIFT) & 235 DARTMAP_RPNMASK); 236 237 /* Map in DART registers */ 238 dart = ioremap(r.start, r.end - r.start + 1); 239 if (dart == NULL) 240 panic("DART: Cannot map registers!"); 241 242 /* Map in DART table */ 243 dart_vbase = ioremap(virt_to_abs(dart_tablebase), dart_tablesize); 244 245 /* Fill initial table */ 246 for (i = 0; i < dart_tablesize/4; i++) 247 dart_vbase[i] = dart_emptyval; 248 249 /* Initialize DART with table base and enable it. */ 250 base = dart_tablebase >> DART_PAGE_SHIFT; 251 size = dart_tablesize >> DART_PAGE_SHIFT; 252 if (dart_is_u4) { 253 size &= DART_SIZE_U4_SIZE_MASK; 254 DART_OUT(DART_BASE_U4, base); 255 DART_OUT(DART_SIZE_U4, size); 256 DART_OUT(DART_CNTL, DART_CNTL_U4_ENABLE); 257 } else { 258 size &= DART_CNTL_U3_SIZE_MASK; 259 DART_OUT(DART_CNTL, 260 DART_CNTL_U3_ENABLE | 261 (base << DART_CNTL_U3_BASE_SHIFT) | 262 (size << DART_CNTL_U3_SIZE_SHIFT)); 263 } 264 265 /* Invalidate DART to get rid of possible stale TLBs */ 266 dart_tlb_invalidate_all(); 267 268 printk(KERN_INFO "DART IOMMU initialized for %s type chipset\n", 269 dart_is_u4 ? "U4" : "U3"); 270 271 return 0; 272 } 273 274 static void iommu_table_dart_setup(void) 275 { 276 iommu_table_dart.it_busno = 0; 277 iommu_table_dart.it_offset = 0; 278 /* it_size is in number of entries */ 279 iommu_table_dart.it_size = dart_tablesize / sizeof(u32); 280 281 /* Initialize the common IOMMU code */ 282 iommu_table_dart.it_base = (unsigned long)dart_vbase; 283 iommu_table_dart.it_index = 0; 284 iommu_table_dart.it_blocksize = 1; 285 iommu_init_table(&iommu_table_dart, -1); 286 287 /* Reserve the last page of the DART to avoid possible prefetch 288 * past the DART mapped area 289 */ 290 set_bit(iommu_table_dart.it_size - 1, iommu_table_dart.it_map); 291 } 292 293 static void pci_dma_dev_setup_dart(struct pci_dev *dev) 294 { 295 /* We only have one iommu table on the mac for now, which makes 296 * things simple. Setup all PCI devices to point to this table 297 */ 298 dev->dev.archdata.dma_data = &iommu_table_dart; 299 } 300 301 static void pci_dma_bus_setup_dart(struct pci_bus *bus) 302 { 303 struct device_node *dn; 304 305 if (!iommu_table_dart_inited) { 306 iommu_table_dart_inited = 1; 307 iommu_table_dart_setup(); 308 } 309 310 dn = pci_bus_to_OF_node(bus); 311 312 if (dn) 313 PCI_DN(dn)->iommu_table = &iommu_table_dart; 314 } 315 316 void iommu_init_early_dart(void) 317 { 318 struct device_node *dn; 319 320 /* Find the DART in the device-tree */ 321 dn = of_find_compatible_node(NULL, "dart", "u3-dart"); 322 if (dn == NULL) { 323 dn = of_find_compatible_node(NULL, "dart", "u4-dart"); 324 if (dn == NULL) 325 goto bail; 326 dart_is_u4 = 1; 327 } 328 329 /* Setup low level TCE operations for the core IOMMU code */ 330 ppc_md.tce_build = dart_build; 331 ppc_md.tce_free = dart_free; 332 ppc_md.tce_flush = dart_flush; 333 334 /* Initialize the DART HW */ 335 if (dart_init(dn) == 0) { 336 ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_dart; 337 ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_dart; 338 339 /* Setup pci_dma ops */ 340 set_pci_dma_ops(&dma_iommu_ops); 341 return; 342 } 343 344 bail: 345 /* If init failed, use direct iommu and null setup functions */ 346 ppc_md.pci_dma_dev_setup = NULL; 347 ppc_md.pci_dma_bus_setup = NULL; 348 349 /* Setup pci_dma ops */ 350 set_pci_dma_ops(&dma_direct_ops); 351 } 352 353 #ifdef CONFIG_PM 354 static void iommu_dart_save(void) 355 { 356 memcpy(dart_copy, dart_vbase, 2*1024*1024); 357 } 358 359 static void iommu_dart_restore(void) 360 { 361 memcpy(dart_vbase, dart_copy, 2*1024*1024); 362 dart_tlb_invalidate_all(); 363 } 364 365 static int __init iommu_init_late_dart(void) 366 { 367 unsigned long tbasepfn; 368 struct page *p; 369 370 /* if no dart table exists then we won't need to save it 371 * and the area has also not been reserved */ 372 if (!dart_tablebase) 373 return 0; 374 375 tbasepfn = __pa(dart_tablebase) >> PAGE_SHIFT; 376 register_nosave_region_late(tbasepfn, 377 tbasepfn + ((1<<24) >> PAGE_SHIFT)); 378 379 /* For suspend we need to copy the dart contents because 380 * it is not part of the regular mapping (see above) and 381 * thus not saved automatically. The memory for this copy 382 * must be allocated early because we need 2 MB. */ 383 p = alloc_pages(GFP_KERNEL, 21 - PAGE_SHIFT); 384 BUG_ON(!p); 385 dart_copy = page_address(p); 386 387 ppc_md.iommu_save = iommu_dart_save; 388 ppc_md.iommu_restore = iommu_dart_restore; 389 390 return 0; 391 } 392 393 late_initcall(iommu_init_late_dart); 394 #endif 395 396 void __init alloc_dart_table(void) 397 { 398 /* Only reserve DART space if machine has more than 1GB of RAM 399 * or if requested with iommu=on on cmdline. 400 * 401 * 1GB of RAM is picked as limit because some default devices 402 * (i.e. Airport Extreme) have 30 bit address range limits. 403 */ 404 405 if (iommu_is_off) 406 return; 407 408 if (!iommu_force_on && lmb_end_of_DRAM() <= 0x40000000ull) 409 return; 410 411 /* 512 pages (2MB) is max DART tablesize. */ 412 dart_tablesize = 1UL << 21; 413 /* 16MB (1 << 24) alignment. We allocate a full 16Mb chuck since we 414 * will blow up an entire large page anyway in the kernel mapping 415 */ 416 dart_tablebase = (unsigned long) 417 abs_to_virt(lmb_alloc_base(1UL<<24, 1UL<<24, 0x80000000L)); 418 419 printk(KERN_INFO "DART table allocated at: %lx\n", dart_tablebase); 420 } 421