1 /* 2 * Copyright (C) 2006-2007 PA Semi, Inc 3 * 4 * Common functions for DMA access on PA Semi PWRficient 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 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 */ 19 20 #include <linux/kernel.h> 21 #include <linux/export.h> 22 #include <linux/pci.h> 23 #include <linux/slab.h> 24 #include <linux/of.h> 25 #include <linux/sched.h> 26 27 #include <asm/pasemi_dma.h> 28 29 #define MAX_TXCH 64 30 #define MAX_RXCH 64 31 #define MAX_FLAGS 64 32 #define MAX_FUN 8 33 34 static struct pasdma_status *dma_status; 35 36 static void __iomem *iob_regs; 37 static void __iomem *mac_regs[6]; 38 static void __iomem *dma_regs; 39 40 static int base_hw_irq; 41 42 static int num_txch, num_rxch; 43 44 static struct pci_dev *dma_pdev; 45 46 /* Bitmaps to handle allocation of channels */ 47 48 static DECLARE_BITMAP(txch_free, MAX_TXCH); 49 static DECLARE_BITMAP(rxch_free, MAX_RXCH); 50 static DECLARE_BITMAP(flags_free, MAX_FLAGS); 51 static DECLARE_BITMAP(fun_free, MAX_FUN); 52 53 /* pasemi_read_iob_reg - read IOB register 54 * @reg: Register to read (offset into PCI CFG space) 55 */ 56 unsigned int pasemi_read_iob_reg(unsigned int reg) 57 { 58 return in_le32(iob_regs+reg); 59 } 60 EXPORT_SYMBOL(pasemi_read_iob_reg); 61 62 /* pasemi_write_iob_reg - write IOB register 63 * @reg: Register to write to (offset into PCI CFG space) 64 * @val: Value to write 65 */ 66 void pasemi_write_iob_reg(unsigned int reg, unsigned int val) 67 { 68 out_le32(iob_regs+reg, val); 69 } 70 EXPORT_SYMBOL(pasemi_write_iob_reg); 71 72 /* pasemi_read_mac_reg - read MAC register 73 * @intf: MAC interface 74 * @reg: Register to read (offset into PCI CFG space) 75 */ 76 unsigned int pasemi_read_mac_reg(int intf, unsigned int reg) 77 { 78 return in_le32(mac_regs[intf]+reg); 79 } 80 EXPORT_SYMBOL(pasemi_read_mac_reg); 81 82 /* pasemi_write_mac_reg - write MAC register 83 * @intf: MAC interface 84 * @reg: Register to write to (offset into PCI CFG space) 85 * @val: Value to write 86 */ 87 void pasemi_write_mac_reg(int intf, unsigned int reg, unsigned int val) 88 { 89 out_le32(mac_regs[intf]+reg, val); 90 } 91 EXPORT_SYMBOL(pasemi_write_mac_reg); 92 93 /* pasemi_read_dma_reg - read DMA register 94 * @reg: Register to read (offset into PCI CFG space) 95 */ 96 unsigned int pasemi_read_dma_reg(unsigned int reg) 97 { 98 return in_le32(dma_regs+reg); 99 } 100 EXPORT_SYMBOL(pasemi_read_dma_reg); 101 102 /* pasemi_write_dma_reg - write DMA register 103 * @reg: Register to write to (offset into PCI CFG space) 104 * @val: Value to write 105 */ 106 void pasemi_write_dma_reg(unsigned int reg, unsigned int val) 107 { 108 out_le32(dma_regs+reg, val); 109 } 110 EXPORT_SYMBOL(pasemi_write_dma_reg); 111 112 static int pasemi_alloc_tx_chan(enum pasemi_dmachan_type type) 113 { 114 int bit; 115 int start, limit; 116 117 switch (type & (TXCHAN_EVT0|TXCHAN_EVT1)) { 118 case TXCHAN_EVT0: 119 start = 0; 120 limit = 10; 121 break; 122 case TXCHAN_EVT1: 123 start = 10; 124 limit = MAX_TXCH; 125 break; 126 default: 127 start = 0; 128 limit = MAX_TXCH; 129 break; 130 } 131 retry: 132 bit = find_next_bit(txch_free, MAX_TXCH, start); 133 if (bit >= limit) 134 return -ENOSPC; 135 if (!test_and_clear_bit(bit, txch_free)) 136 goto retry; 137 138 return bit; 139 } 140 141 static void pasemi_free_tx_chan(int chan) 142 { 143 BUG_ON(test_bit(chan, txch_free)); 144 set_bit(chan, txch_free); 145 } 146 147 static int pasemi_alloc_rx_chan(void) 148 { 149 int bit; 150 retry: 151 bit = find_first_bit(rxch_free, MAX_RXCH); 152 if (bit >= MAX_TXCH) 153 return -ENOSPC; 154 if (!test_and_clear_bit(bit, rxch_free)) 155 goto retry; 156 157 return bit; 158 } 159 160 static void pasemi_free_rx_chan(int chan) 161 { 162 BUG_ON(test_bit(chan, rxch_free)); 163 set_bit(chan, rxch_free); 164 } 165 166 /* pasemi_dma_alloc_chan - Allocate a DMA channel 167 * @type: Type of channel to allocate 168 * @total_size: Total size of structure to allocate (to allow for more 169 * room behind the structure to be used by the client) 170 * @offset: Offset in bytes from start of the total structure to the beginning 171 * of struct pasemi_dmachan. Needed when struct pasemi_dmachan is 172 * not the first member of the client structure. 173 * 174 * pasemi_dma_alloc_chan allocates a DMA channel for use by a client. The 175 * type argument specifies whether it's a RX or TX channel, and in the case 176 * of TX channels which group it needs to belong to (if any). 177 * 178 * Returns a pointer to the total structure allocated on success, NULL 179 * on failure. 180 */ 181 void *pasemi_dma_alloc_chan(enum pasemi_dmachan_type type, 182 int total_size, int offset) 183 { 184 void *buf; 185 struct pasemi_dmachan *chan; 186 int chno; 187 188 BUG_ON(total_size < sizeof(struct pasemi_dmachan)); 189 190 buf = kzalloc(total_size, GFP_KERNEL); 191 192 if (!buf) 193 return NULL; 194 chan = buf + offset; 195 196 chan->priv = buf; 197 198 switch (type & (TXCHAN|RXCHAN)) { 199 case RXCHAN: 200 chno = pasemi_alloc_rx_chan(); 201 chan->chno = chno; 202 chan->irq = irq_create_mapping(NULL, 203 base_hw_irq + num_txch + chno); 204 chan->status = &dma_status->rx_sta[chno]; 205 break; 206 case TXCHAN: 207 chno = pasemi_alloc_tx_chan(type); 208 chan->chno = chno; 209 chan->irq = irq_create_mapping(NULL, base_hw_irq + chno); 210 chan->status = &dma_status->tx_sta[chno]; 211 break; 212 } 213 214 chan->chan_type = type; 215 216 return chan; 217 } 218 EXPORT_SYMBOL(pasemi_dma_alloc_chan); 219 220 /* pasemi_dma_free_chan - Free a previously allocated channel 221 * @chan: Channel to free 222 * 223 * Frees a previously allocated channel. It will also deallocate any 224 * descriptor ring associated with the channel, if allocated. 225 */ 226 void pasemi_dma_free_chan(struct pasemi_dmachan *chan) 227 { 228 if (chan->ring_virt) 229 pasemi_dma_free_ring(chan); 230 231 switch (chan->chan_type & (RXCHAN|TXCHAN)) { 232 case RXCHAN: 233 pasemi_free_rx_chan(chan->chno); 234 break; 235 case TXCHAN: 236 pasemi_free_tx_chan(chan->chno); 237 break; 238 } 239 240 kfree(chan->priv); 241 } 242 EXPORT_SYMBOL(pasemi_dma_free_chan); 243 244 /* pasemi_dma_alloc_ring - Allocate descriptor ring for a channel 245 * @chan: Channel for which to allocate 246 * @ring_size: Ring size in 64-bit (8-byte) words 247 * 248 * Allocate a descriptor ring for a channel. Returns 0 on success, errno 249 * on failure. The passed in struct pasemi_dmachan is updated with the 250 * virtual and DMA addresses of the ring. 251 */ 252 int pasemi_dma_alloc_ring(struct pasemi_dmachan *chan, int ring_size) 253 { 254 BUG_ON(chan->ring_virt); 255 256 chan->ring_size = ring_size; 257 258 chan->ring_virt = dma_alloc_coherent(&dma_pdev->dev, 259 ring_size * sizeof(u64), 260 &chan->ring_dma, GFP_KERNEL); 261 262 if (!chan->ring_virt) 263 return -ENOMEM; 264 265 memset(chan->ring_virt, 0, ring_size * sizeof(u64)); 266 267 return 0; 268 } 269 EXPORT_SYMBOL(pasemi_dma_alloc_ring); 270 271 /* pasemi_dma_free_ring - Free an allocated descriptor ring for a channel 272 * @chan: Channel for which to free the descriptor ring 273 * 274 * Frees a previously allocated descriptor ring for a channel. 275 */ 276 void pasemi_dma_free_ring(struct pasemi_dmachan *chan) 277 { 278 BUG_ON(!chan->ring_virt); 279 280 dma_free_coherent(&dma_pdev->dev, chan->ring_size * sizeof(u64), 281 chan->ring_virt, chan->ring_dma); 282 chan->ring_virt = NULL; 283 chan->ring_size = 0; 284 chan->ring_dma = 0; 285 } 286 EXPORT_SYMBOL(pasemi_dma_free_ring); 287 288 /* pasemi_dma_start_chan - Start a DMA channel 289 * @chan: Channel to start 290 * @cmdsta: Additional CCMDSTA/TCMDSTA bits to write 291 * 292 * Enables (starts) a DMA channel with optional additional arguments. 293 */ 294 void pasemi_dma_start_chan(const struct pasemi_dmachan *chan, const u32 cmdsta) 295 { 296 if (chan->chan_type == RXCHAN) 297 pasemi_write_dma_reg(PAS_DMA_RXCHAN_CCMDSTA(chan->chno), 298 cmdsta | PAS_DMA_RXCHAN_CCMDSTA_EN); 299 else 300 pasemi_write_dma_reg(PAS_DMA_TXCHAN_TCMDSTA(chan->chno), 301 cmdsta | PAS_DMA_TXCHAN_TCMDSTA_EN); 302 } 303 EXPORT_SYMBOL(pasemi_dma_start_chan); 304 305 /* pasemi_dma_stop_chan - Stop a DMA channel 306 * @chan: Channel to stop 307 * 308 * Stops (disables) a DMA channel. This is done by setting the ST bit in the 309 * CMDSTA register and waiting on the ACT (active) bit to clear, then 310 * finally disabling the whole channel. 311 * 312 * This function will only try for a short while for the channel to stop, if 313 * it doesn't it will return failure. 314 * 315 * Returns 1 on success, 0 on failure. 316 */ 317 #define MAX_RETRIES 5000 318 int pasemi_dma_stop_chan(const struct pasemi_dmachan *chan) 319 { 320 int reg, retries; 321 u32 sta; 322 323 if (chan->chan_type == RXCHAN) { 324 reg = PAS_DMA_RXCHAN_CCMDSTA(chan->chno); 325 pasemi_write_dma_reg(reg, PAS_DMA_RXCHAN_CCMDSTA_ST); 326 for (retries = 0; retries < MAX_RETRIES; retries++) { 327 sta = pasemi_read_dma_reg(reg); 328 if (!(sta & PAS_DMA_RXCHAN_CCMDSTA_ACT)) { 329 pasemi_write_dma_reg(reg, 0); 330 return 1; 331 } 332 cond_resched(); 333 } 334 } else { 335 reg = PAS_DMA_TXCHAN_TCMDSTA(chan->chno); 336 pasemi_write_dma_reg(reg, PAS_DMA_TXCHAN_TCMDSTA_ST); 337 for (retries = 0; retries < MAX_RETRIES; retries++) { 338 sta = pasemi_read_dma_reg(reg); 339 if (!(sta & PAS_DMA_TXCHAN_TCMDSTA_ACT)) { 340 pasemi_write_dma_reg(reg, 0); 341 return 1; 342 } 343 cond_resched(); 344 } 345 } 346 347 return 0; 348 } 349 EXPORT_SYMBOL(pasemi_dma_stop_chan); 350 351 /* pasemi_dma_alloc_buf - Allocate a buffer to use for DMA 352 * @chan: Channel to allocate for 353 * @size: Size of buffer in bytes 354 * @handle: DMA handle 355 * 356 * Allocate a buffer to be used by the DMA engine for read/write, 357 * similar to dma_alloc_coherent(). 358 * 359 * Returns the virtual address of the buffer, or NULL in case of failure. 360 */ 361 void *pasemi_dma_alloc_buf(struct pasemi_dmachan *chan, int size, 362 dma_addr_t *handle) 363 { 364 return dma_alloc_coherent(&dma_pdev->dev, size, handle, GFP_KERNEL); 365 } 366 EXPORT_SYMBOL(pasemi_dma_alloc_buf); 367 368 /* pasemi_dma_free_buf - Free a buffer used for DMA 369 * @chan: Channel the buffer was allocated for 370 * @size: Size of buffer in bytes 371 * @handle: DMA handle 372 * 373 * Frees a previously allocated buffer. 374 */ 375 void pasemi_dma_free_buf(struct pasemi_dmachan *chan, int size, 376 dma_addr_t *handle) 377 { 378 dma_free_coherent(&dma_pdev->dev, size, handle, GFP_KERNEL); 379 } 380 EXPORT_SYMBOL(pasemi_dma_free_buf); 381 382 /* pasemi_dma_alloc_flag - Allocate a flag (event) for channel synchronization 383 * 384 * Allocates a flag for use with channel synchronization (event descriptors). 385 * Returns allocated flag (0-63), < 0 on error. 386 */ 387 int pasemi_dma_alloc_flag(void) 388 { 389 int bit; 390 391 retry: 392 bit = find_next_bit(flags_free, MAX_FLAGS, 0); 393 if (bit >= MAX_FLAGS) 394 return -ENOSPC; 395 if (!test_and_clear_bit(bit, flags_free)) 396 goto retry; 397 398 return bit; 399 } 400 EXPORT_SYMBOL(pasemi_dma_alloc_flag); 401 402 403 /* pasemi_dma_free_flag - Deallocates a flag (event) 404 * @flag: Flag number to deallocate 405 * 406 * Frees up a flag so it can be reused for other purposes. 407 */ 408 void pasemi_dma_free_flag(int flag) 409 { 410 BUG_ON(test_bit(flag, flags_free)); 411 BUG_ON(flag >= MAX_FLAGS); 412 set_bit(flag, flags_free); 413 } 414 EXPORT_SYMBOL(pasemi_dma_free_flag); 415 416 417 /* pasemi_dma_set_flag - Sets a flag (event) to 1 418 * @flag: Flag number to set active 419 * 420 * Sets the flag provided to 1. 421 */ 422 void pasemi_dma_set_flag(int flag) 423 { 424 BUG_ON(flag >= MAX_FLAGS); 425 if (flag < 32) 426 pasemi_write_dma_reg(PAS_DMA_TXF_SFLG0, 1 << flag); 427 else 428 pasemi_write_dma_reg(PAS_DMA_TXF_SFLG1, 1 << flag); 429 } 430 EXPORT_SYMBOL(pasemi_dma_set_flag); 431 432 /* pasemi_dma_clear_flag - Sets a flag (event) to 0 433 * @flag: Flag number to set inactive 434 * 435 * Sets the flag provided to 0. 436 */ 437 void pasemi_dma_clear_flag(int flag) 438 { 439 BUG_ON(flag >= MAX_FLAGS); 440 if (flag < 32) 441 pasemi_write_dma_reg(PAS_DMA_TXF_CFLG0, 1 << flag); 442 else 443 pasemi_write_dma_reg(PAS_DMA_TXF_CFLG1, 1 << flag); 444 } 445 EXPORT_SYMBOL(pasemi_dma_clear_flag); 446 447 /* pasemi_dma_alloc_fun - Allocate a function engine 448 * 449 * Allocates a function engine to use for crypto/checksum offload 450 * Returns allocated engine (0-8), < 0 on error. 451 */ 452 int pasemi_dma_alloc_fun(void) 453 { 454 int bit; 455 456 retry: 457 bit = find_next_bit(fun_free, MAX_FLAGS, 0); 458 if (bit >= MAX_FLAGS) 459 return -ENOSPC; 460 if (!test_and_clear_bit(bit, fun_free)) 461 goto retry; 462 463 return bit; 464 } 465 EXPORT_SYMBOL(pasemi_dma_alloc_fun); 466 467 468 /* pasemi_dma_free_fun - Deallocates a function engine 469 * @flag: Engine number to deallocate 470 * 471 * Frees up a function engine so it can be used for other purposes. 472 */ 473 void pasemi_dma_free_fun(int fun) 474 { 475 BUG_ON(test_bit(fun, fun_free)); 476 BUG_ON(fun >= MAX_FLAGS); 477 set_bit(fun, fun_free); 478 } 479 EXPORT_SYMBOL(pasemi_dma_free_fun); 480 481 482 static void *map_onedev(struct pci_dev *p, int index) 483 { 484 struct device_node *dn; 485 void __iomem *ret; 486 487 dn = pci_device_to_OF_node(p); 488 if (!dn) 489 goto fallback; 490 491 ret = of_iomap(dn, index); 492 if (!ret) 493 goto fallback; 494 495 return ret; 496 fallback: 497 /* This is hardcoded and ugly, but we have some firmware versions 498 * that don't provide the register space in the device tree. Luckily 499 * they are at well-known locations so we can just do the math here. 500 */ 501 return ioremap(0xe0000000 + (p->devfn << 12), 0x2000); 502 } 503 504 /* pasemi_dma_init - Initialize the PA Semi DMA library 505 * 506 * This function initializes the DMA library. It must be called before 507 * any other function in the library. 508 * 509 * Returns 0 on success, errno on failure. 510 */ 511 int pasemi_dma_init(void) 512 { 513 static DEFINE_SPINLOCK(init_lock); 514 struct pci_dev *iob_pdev; 515 struct pci_dev *pdev; 516 struct resource res; 517 struct device_node *dn; 518 int i, intf, err = 0; 519 unsigned long timeout; 520 u32 tmp; 521 522 if (!machine_is(pasemi)) 523 return -ENODEV; 524 525 spin_lock(&init_lock); 526 527 /* Make sure we haven't already initialized */ 528 if (dma_pdev) 529 goto out; 530 531 iob_pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa001, NULL); 532 if (!iob_pdev) { 533 BUG(); 534 printk(KERN_WARNING "Can't find I/O Bridge\n"); 535 err = -ENODEV; 536 goto out; 537 } 538 iob_regs = map_onedev(iob_pdev, 0); 539 540 dma_pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa007, NULL); 541 if (!dma_pdev) { 542 BUG(); 543 printk(KERN_WARNING "Can't find DMA controller\n"); 544 err = -ENODEV; 545 goto out; 546 } 547 dma_regs = map_onedev(dma_pdev, 0); 548 base_hw_irq = virq_to_hw(dma_pdev->irq); 549 550 pci_read_config_dword(dma_pdev, PAS_DMA_CAP_TXCH, &tmp); 551 num_txch = (tmp & PAS_DMA_CAP_TXCH_TCHN_M) >> PAS_DMA_CAP_TXCH_TCHN_S; 552 553 pci_read_config_dword(dma_pdev, PAS_DMA_CAP_RXCH, &tmp); 554 num_rxch = (tmp & PAS_DMA_CAP_RXCH_RCHN_M) >> PAS_DMA_CAP_RXCH_RCHN_S; 555 556 intf = 0; 557 for (pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa006, NULL); 558 pdev; 559 pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa006, pdev)) 560 mac_regs[intf++] = map_onedev(pdev, 0); 561 562 pci_dev_put(pdev); 563 564 for (pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa005, NULL); 565 pdev; 566 pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa005, pdev)) 567 mac_regs[intf++] = map_onedev(pdev, 0); 568 569 pci_dev_put(pdev); 570 571 dn = pci_device_to_OF_node(iob_pdev); 572 if (dn) 573 err = of_address_to_resource(dn, 1, &res); 574 if (!dn || err) { 575 /* Fallback for old firmware */ 576 res.start = 0xfd800000; 577 res.end = res.start + 0x1000; 578 } 579 dma_status = __ioremap(res.start, resource_size(&res), 0); 580 pci_dev_put(iob_pdev); 581 582 for (i = 0; i < MAX_TXCH; i++) 583 __set_bit(i, txch_free); 584 585 for (i = 0; i < MAX_RXCH; i++) 586 __set_bit(i, rxch_free); 587 588 timeout = jiffies + HZ; 589 pasemi_write_dma_reg(PAS_DMA_COM_RXCMD, 0); 590 while (pasemi_read_dma_reg(PAS_DMA_COM_RXSTA) & 1) { 591 if (time_after(jiffies, timeout)) { 592 pr_warn("Warning: Could not disable RX section\n"); 593 break; 594 } 595 } 596 597 timeout = jiffies + HZ; 598 pasemi_write_dma_reg(PAS_DMA_COM_TXCMD, 0); 599 while (pasemi_read_dma_reg(PAS_DMA_COM_TXSTA) & 1) { 600 if (time_after(jiffies, timeout)) { 601 pr_warn("Warning: Could not disable TX section\n"); 602 break; 603 } 604 } 605 606 /* setup resource allocations for the different DMA sections */ 607 tmp = pasemi_read_dma_reg(PAS_DMA_COM_CFG); 608 pasemi_write_dma_reg(PAS_DMA_COM_CFG, tmp | 0x18000000); 609 610 /* enable tx section */ 611 pasemi_write_dma_reg(PAS_DMA_COM_TXCMD, PAS_DMA_COM_TXCMD_EN); 612 613 /* enable rx section */ 614 pasemi_write_dma_reg(PAS_DMA_COM_RXCMD, PAS_DMA_COM_RXCMD_EN); 615 616 for (i = 0; i < MAX_FLAGS; i++) 617 __set_bit(i, flags_free); 618 619 for (i = 0; i < MAX_FUN; i++) 620 __set_bit(i, fun_free); 621 622 /* clear all status flags */ 623 pasemi_write_dma_reg(PAS_DMA_TXF_CFLG0, 0xffffffff); 624 pasemi_write_dma_reg(PAS_DMA_TXF_CFLG1, 0xffffffff); 625 626 printk(KERN_INFO "PA Semi PWRficient DMA library initialized " 627 "(%d tx, %d rx channels)\n", num_txch, num_rxch); 628 629 out: 630 spin_unlock(&init_lock); 631 return err; 632 } 633 EXPORT_SYMBOL(pasemi_dma_init); 634