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 <linux/lmb.h> 41 #include <asm/io.h> 42 #include <asm/prom.h> 43 #include <asm/iommu.h> 44 #include <asm/pci-bridge.h> 45 #include <asm/machdep.h> 46 #include <asm/abs_addr.h> 47 #include <asm/cacheflush.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 int dart_build(struct iommu_table *tbl, long index, 151 long npages, unsigned long uaddr, 152 enum dma_data_direction direction, 153 struct dma_attrs *attrs) 154 { 155 unsigned int *dp; 156 unsigned int rpn; 157 long l; 158 159 DBG("dart: build at: %lx, %lx, addr: %x\n", index, npages, uaddr); 160 161 dp = ((unsigned int*)tbl->it_base) + index; 162 163 /* On U3, all memory is contiguous, so we can move this 164 * out of the loop. 165 */ 166 l = npages; 167 while (l--) { 168 rpn = virt_to_abs(uaddr) >> DART_PAGE_SHIFT; 169 170 *(dp++) = DARTMAP_VALID | (rpn & DARTMAP_RPNMASK); 171 172 uaddr += DART_PAGE_SIZE; 173 } 174 175 /* make sure all updates have reached memory */ 176 mb(); 177 in_be32((unsigned __iomem *)dp); 178 mb(); 179 180 if (dart_is_u4) { 181 rpn = index; 182 while (npages--) 183 dart_tlb_invalidate_one(rpn++); 184 } else { 185 dart_dirty = 1; 186 } 187 return 0; 188 } 189 190 191 static void dart_free(struct iommu_table *tbl, long index, long npages) 192 { 193 unsigned int *dp; 194 195 /* We don't worry about flushing the TLB cache. The only drawback of 196 * not doing it is that we won't catch buggy device drivers doing 197 * bad DMAs, but then no 32-bit architecture ever does either. 198 */ 199 200 DBG("dart: free at: %lx, %lx\n", index, npages); 201 202 dp = ((unsigned int *)tbl->it_base) + index; 203 204 while (npages--) 205 *(dp++) = dart_emptyval; 206 } 207 208 209 static int __init dart_init(struct device_node *dart_node) 210 { 211 unsigned int i; 212 unsigned long tmp, base, size; 213 struct resource r; 214 215 if (dart_tablebase == 0 || dart_tablesize == 0) { 216 printk(KERN_INFO "DART: table not allocated, using " 217 "direct DMA\n"); 218 return -ENODEV; 219 } 220 221 if (of_address_to_resource(dart_node, 0, &r)) 222 panic("DART: can't get register base ! "); 223 224 /* Make sure nothing from the DART range remains in the CPU cache 225 * from a previous mapping that existed before the kernel took 226 * over 227 */ 228 flush_dcache_phys_range(dart_tablebase, 229 dart_tablebase + dart_tablesize); 230 231 /* Allocate a spare page to map all invalid DART pages. We need to do 232 * that to work around what looks like a problem with the HT bridge 233 * prefetching into invalid pages and corrupting data 234 */ 235 tmp = lmb_alloc(DART_PAGE_SIZE, DART_PAGE_SIZE); 236 dart_emptyval = DARTMAP_VALID | ((tmp >> DART_PAGE_SHIFT) & 237 DARTMAP_RPNMASK); 238 239 /* Map in DART registers */ 240 dart = ioremap(r.start, r.end - r.start + 1); 241 if (dart == NULL) 242 panic("DART: Cannot map registers!"); 243 244 /* Map in DART table */ 245 dart_vbase = ioremap(virt_to_abs(dart_tablebase), dart_tablesize); 246 247 /* Fill initial table */ 248 for (i = 0; i < dart_tablesize/4; i++) 249 dart_vbase[i] = dart_emptyval; 250 251 /* Initialize DART with table base and enable it. */ 252 base = dart_tablebase >> DART_PAGE_SHIFT; 253 size = dart_tablesize >> DART_PAGE_SHIFT; 254 if (dart_is_u4) { 255 size &= DART_SIZE_U4_SIZE_MASK; 256 DART_OUT(DART_BASE_U4, base); 257 DART_OUT(DART_SIZE_U4, size); 258 DART_OUT(DART_CNTL, DART_CNTL_U4_ENABLE); 259 } else { 260 size &= DART_CNTL_U3_SIZE_MASK; 261 DART_OUT(DART_CNTL, 262 DART_CNTL_U3_ENABLE | 263 (base << DART_CNTL_U3_BASE_SHIFT) | 264 (size << DART_CNTL_U3_SIZE_SHIFT)); 265 } 266 267 /* Invalidate DART to get rid of possible stale TLBs */ 268 dart_tlb_invalidate_all(); 269 270 printk(KERN_INFO "DART IOMMU initialized for %s type chipset\n", 271 dart_is_u4 ? "U4" : "U3"); 272 273 return 0; 274 } 275 276 static void iommu_table_dart_setup(void) 277 { 278 iommu_table_dart.it_busno = 0; 279 iommu_table_dart.it_offset = 0; 280 /* it_size is in number of entries */ 281 iommu_table_dart.it_size = dart_tablesize / sizeof(u32); 282 283 /* Initialize the common IOMMU code */ 284 iommu_table_dart.it_base = (unsigned long)dart_vbase; 285 iommu_table_dart.it_index = 0; 286 iommu_table_dart.it_blocksize = 1; 287 iommu_init_table(&iommu_table_dart, -1); 288 289 /* Reserve the last page of the DART to avoid possible prefetch 290 * past the DART mapped area 291 */ 292 set_bit(iommu_table_dart.it_size - 1, iommu_table_dart.it_map); 293 } 294 295 static void pci_dma_dev_setup_dart(struct pci_dev *dev) 296 { 297 /* We only have one iommu table on the mac for now, which makes 298 * things simple. Setup all PCI devices to point to this table 299 */ 300 set_iommu_table_base(&dev->dev, &iommu_table_dart); 301 } 302 303 static void pci_dma_bus_setup_dart(struct pci_bus *bus) 304 { 305 struct device_node *dn; 306 307 if (!iommu_table_dart_inited) { 308 iommu_table_dart_inited = 1; 309 iommu_table_dart_setup(); 310 } 311 312 dn = pci_bus_to_OF_node(bus); 313 314 if (dn) 315 PCI_DN(dn)->iommu_table = &iommu_table_dart; 316 } 317 318 void __init iommu_init_early_dart(void) 319 { 320 struct device_node *dn; 321 322 /* Find the DART in the device-tree */ 323 dn = of_find_compatible_node(NULL, "dart", "u3-dart"); 324 if (dn == NULL) { 325 dn = of_find_compatible_node(NULL, "dart", "u4-dart"); 326 if (dn == NULL) 327 goto bail; 328 dart_is_u4 = 1; 329 } 330 331 /* Setup low level TCE operations for the core IOMMU code */ 332 ppc_md.tce_build = dart_build; 333 ppc_md.tce_free = dart_free; 334 ppc_md.tce_flush = dart_flush; 335 336 /* Initialize the DART HW */ 337 if (dart_init(dn) == 0) { 338 ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_dart; 339 ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_dart; 340 341 /* Setup pci_dma ops */ 342 set_pci_dma_ops(&dma_iommu_ops); 343 return; 344 } 345 346 bail: 347 /* If init failed, use direct iommu and null setup functions */ 348 ppc_md.pci_dma_dev_setup = NULL; 349 ppc_md.pci_dma_bus_setup = NULL; 350 351 /* Setup pci_dma ops */ 352 set_pci_dma_ops(&dma_direct_ops); 353 } 354 355 #ifdef CONFIG_PM 356 static void iommu_dart_save(void) 357 { 358 memcpy(dart_copy, dart_vbase, 2*1024*1024); 359 } 360 361 static void iommu_dart_restore(void) 362 { 363 memcpy(dart_vbase, dart_copy, 2*1024*1024); 364 dart_tlb_invalidate_all(); 365 } 366 367 static int __init iommu_init_late_dart(void) 368 { 369 unsigned long tbasepfn; 370 struct page *p; 371 372 /* if no dart table exists then we won't need to save it 373 * and the area has also not been reserved */ 374 if (!dart_tablebase) 375 return 0; 376 377 tbasepfn = __pa(dart_tablebase) >> PAGE_SHIFT; 378 register_nosave_region_late(tbasepfn, 379 tbasepfn + ((1<<24) >> PAGE_SHIFT)); 380 381 /* For suspend we need to copy the dart contents because 382 * it is not part of the regular mapping (see above) and 383 * thus not saved automatically. The memory for this copy 384 * must be allocated early because we need 2 MB. */ 385 p = alloc_pages(GFP_KERNEL, 21 - PAGE_SHIFT); 386 BUG_ON(!p); 387 dart_copy = page_address(p); 388 389 ppc_md.iommu_save = iommu_dart_save; 390 ppc_md.iommu_restore = iommu_dart_restore; 391 392 return 0; 393 } 394 395 late_initcall(iommu_init_late_dart); 396 #endif 397 398 void __init alloc_dart_table(void) 399 { 400 /* Only reserve DART space if machine has more than 1GB of RAM 401 * or if requested with iommu=on on cmdline. 402 * 403 * 1GB of RAM is picked as limit because some default devices 404 * (i.e. Airport Extreme) have 30 bit address range limits. 405 */ 406 407 if (iommu_is_off) 408 return; 409 410 if (!iommu_force_on && lmb_end_of_DRAM() <= 0x40000000ull) 411 return; 412 413 /* 512 pages (2MB) is max DART tablesize. */ 414 dart_tablesize = 1UL << 21; 415 /* 16MB (1 << 24) alignment. We allocate a full 16Mb chuck since we 416 * will blow up an entire large page anyway in the kernel mapping 417 */ 418 dart_tablebase = (unsigned long) 419 abs_to_virt(lmb_alloc_base(1UL<<24, 1UL<<24, 0x80000000L)); 420 421 printk(KERN_INFO "DART table allocated at: %lx\n", dart_tablebase); 422 } 423