| 1 | /* |
| 2 | |
| 3 | Copyright 1996,2002,2005 Gregory D. Hager, Alfred A. Rizzi, Noah J. Cowan, |
| 4 | Jason Lapenta, Scott Smedley, Greg Sharp |
| 5 | |
| 6 | This file is part of the DT3155 Device Driver. |
| 7 | |
| 8 | The DT3155 Device Driver is free software; you can redistribute it |
| 9 | and/or modify it under the terms of the GNU General Public License as |
| 10 | published by the Free Software Foundation; either version 2 of the |
| 11 | License, or (at your option) any later version. |
| 12 | |
| 13 | The DT3155 Device Driver is distributed in the hope that it will be |
| 14 | useful, but WITHOUT ANY WARRANTY; without even the implied warranty |
| 15 | of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with the DT3155 Device Driver; if not, write to the Free |
| 20 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
| 21 | MA 02111-1307 USA |
| 22 | |
| 23 | File: dt3155_isr.c |
| 24 | Purpose: Buffer management routines, and other routines for the ISR |
| 25 | (the actual isr is in dt3155_drv.c) |
| 26 | |
| 27 | -- Changes -- |
| 28 | |
| 29 | Date Programmer Description of changes made |
| 30 | ------------------------------------------------------------------- |
| 31 | 03-Jul-2000 JML n/a |
| 32 | 02-Apr-2002 SS Mods to make work with separate allocator |
| 33 | module; Merged John Roll's mods to make work with |
| 34 | multiple boards. |
| 35 | 10-Jul-2002 GCS Complete rewrite of setup_buffers to disallow |
| 36 | buffers which span a 4MB boundary. |
| 37 | 24-Jul-2002 SS GPL licence. |
| 38 | 30-Jul-2002 NJC Added support for buffer loop. |
| 39 | 31-Jul-2002 NJC Complete rewrite of buffer management |
| 40 | 02-Aug-2002 NJC Including slab.h instead of malloc.h (no warning). |
| 41 | Also, allocator_init() now returns allocator_max |
| 42 | so cleaned up allocate_buffers() accordingly. |
| 43 | 08-Aug-2005 SS port to 2.6 kernel. |
| 44 | |
| 45 | */ |
| 46 | |
| 47 | #include <asm/system.h> |
| 48 | #include <linux/gfp.h> |
| 49 | #include <linux/sched.h> |
| 50 | #include <linux/types.h> |
| 51 | |
| 52 | #include "dt3155.h" |
| 53 | #include "dt3155_drv.h" |
| 54 | #include "dt3155_io.h" |
| 55 | #include "dt3155_isr.h" |
| 56 | #include "allocator.h" |
| 57 | |
| 58 | #define FOUR_MB (0x0400000) /* Can't DMA accross a 4MB boundary!*/ |
| 59 | #define UPPER_10_BITS (0x3FF<<22) /* Can't DMA accross a 4MB boundary!*/ |
| 60 | |
| 61 | |
| 62 | /* Pointer into global structure for handling buffers */ |
| 63 | struct dt3155_fbuffer *dt3155_fbuffer[MAXBOARDS] = {NULL |
| 64 | #if MAXBOARDS == 2 |
| 65 | , NULL |
| 66 | #endif |
| 67 | }; |
| 68 | |
| 69 | /****************************************************************************** |
| 70 | * Simple array based que struct |
| 71 | * |
| 72 | * Some handy functions using the buffering structure. |
| 73 | *****************************************************************************/ |
| 74 | |
| 75 | |
| 76 | /*************************** |
| 77 | * are_empty_buffers |
| 78 | * m is minor # of device |
| 79 | ***************************/ |
| 80 | bool are_empty_buffers(int m) |
| 81 | { |
| 82 | return dt3155_fbuffer[m]->empty_len; |
| 83 | } |
| 84 | |
| 85 | /************************** |
| 86 | * push_empty |
| 87 | * m is minor # of device |
| 88 | * |
| 89 | * This is slightly confusing. The number empty_len is the literal # |
| 90 | * of empty buffers. After calling, empty_len-1 is the index into the |
| 91 | * empty buffer stack. So, if empty_len == 1, there is one empty buffer, |
| 92 | * given by dt3155_fbuffer[m]->empty_buffers[0]. |
| 93 | * empty_buffers should never fill up, though this is not checked. |
| 94 | **************************/ |
| 95 | void push_empty(int index, int m) |
| 96 | { |
| 97 | dt3155_fbuffer[m]->empty_buffers[dt3155_fbuffer[m]->empty_len] = index; |
| 98 | dt3155_fbuffer[m]->empty_len++; |
| 99 | } |
| 100 | |
| 101 | /************************** |
| 102 | * pop_empty(m) |
| 103 | * m is minor # of device |
| 104 | **************************/ |
| 105 | int pop_empty(int m) |
| 106 | { |
| 107 | dt3155_fbuffer[m]->empty_len--; |
| 108 | return dt3155_fbuffer[m]->empty_buffers[dt3155_fbuffer[m]->empty_len]; |
| 109 | } |
| 110 | |
| 111 | /************************* |
| 112 | * is_ready_buf_empty(m) |
| 113 | * m is minor # of device |
| 114 | *************************/ |
| 115 | bool is_ready_buf_empty(int m) |
| 116 | { |
| 117 | return ((dt3155_fbuffer[m]->ready_len) == 0); |
| 118 | } |
| 119 | |
| 120 | /************************* |
| 121 | * is_ready_buf_full(m) |
| 122 | * m is minor # of device |
| 123 | * this should *never* be true if there are any active, locked or empty |
| 124 | * buffers, since it corresponds to nbuffers ready buffers!! |
| 125 | * 7/31/02: total rewrite. --NJC |
| 126 | *************************/ |
| 127 | bool is_ready_buf_full(int m) |
| 128 | { |
| 129 | return dt3155_fbuffer[m]->ready_len == dt3155_fbuffer[m]->nbuffers; |
| 130 | } |
| 131 | |
| 132 | /***************************************************** |
| 133 | * push_ready(m, buffer) |
| 134 | * m is minor # of device |
| 135 | * |
| 136 | *****************************************************/ |
| 137 | void push_ready(int m, int index) |
| 138 | { |
| 139 | int head = dt3155_fbuffer[m]->ready_head; |
| 140 | |
| 141 | dt3155_fbuffer[m]->ready_que[head] = index; |
| 142 | dt3155_fbuffer[m]->ready_head = ((head + 1) % |
| 143 | (dt3155_fbuffer[m]->nbuffers)); |
| 144 | dt3155_fbuffer[m]->ready_len++; |
| 145 | |
| 146 | } |
| 147 | |
| 148 | /***************************************************** |
| 149 | * get_tail() |
| 150 | * m is minor # of device |
| 151 | * |
| 152 | * Simply comptutes the tail given the head and the length. |
| 153 | *****************************************************/ |
| 154 | static int get_tail(int m) |
| 155 | { |
| 156 | return (dt3155_fbuffer[m]->ready_head - |
| 157 | dt3155_fbuffer[m]->ready_len + |
| 158 | dt3155_fbuffer[m]->nbuffers)% |
| 159 | (dt3155_fbuffer[m]->nbuffers); |
| 160 | } |
| 161 | |
| 162 | |
| 163 | |
| 164 | /***************************************************** |
| 165 | * pop_ready() |
| 166 | * m is minor # of device |
| 167 | * |
| 168 | * This assumes that there is a ready buffer ready... should |
| 169 | * be checked (e.g. with is_ready_buf_empty() prior to call. |
| 170 | *****************************************************/ |
| 171 | int pop_ready(int m) |
| 172 | { |
| 173 | int tail; |
| 174 | tail = get_tail(m); |
| 175 | dt3155_fbuffer[m]->ready_len--; |
| 176 | return dt3155_fbuffer[m]->ready_que[tail]; |
| 177 | } |
| 178 | |
| 179 | |
| 180 | /***************************************************** |
| 181 | * printques |
| 182 | * m is minor # of device |
| 183 | *****************************************************/ |
| 184 | void printques(int m) |
| 185 | { |
| 186 | int head = dt3155_fbuffer[m]->ready_head; |
| 187 | int tail; |
| 188 | int num = dt3155_fbuffer[m]->nbuffers; |
| 189 | int frame_index; |
| 190 | int index; |
| 191 | |
| 192 | tail = get_tail(m); |
| 193 | |
| 194 | printk("\n R:"); |
| 195 | for (index = tail; index != head; index++, index = index % (num)) { |
| 196 | frame_index = dt3155_fbuffer[m]->ready_que[index]; |
| 197 | printk(" %d ", frame_index); |
| 198 | } |
| 199 | |
| 200 | printk("\n E:"); |
| 201 | for (index = 0; index < dt3155_fbuffer[m]->empty_len; index++) { |
| 202 | frame_index = dt3155_fbuffer[m]->empty_buffers[index]; |
| 203 | printk(" %d ", frame_index); |
| 204 | } |
| 205 | |
| 206 | frame_index = dt3155_fbuffer[m]->active_buf; |
| 207 | printk("\n A: %d", frame_index); |
| 208 | |
| 209 | frame_index = dt3155_fbuffer[m]->locked_buf; |
| 210 | printk("\n L: %d\n", frame_index); |
| 211 | |
| 212 | } |
| 213 | |
| 214 | /***************************************************** |
| 215 | * adjust_4MB |
| 216 | * |
| 217 | * If a buffer intersects the 4MB boundary, push |
| 218 | * the start address up to the beginning of the |
| 219 | * next 4MB chunk (assuming bufsize < 4MB). |
| 220 | *****************************************************/ |
| 221 | u32 adjust_4MB(u32 buf_addr, u32 bufsize) |
| 222 | { |
| 223 | if (((buf_addr+bufsize) & UPPER_10_BITS) != (buf_addr & UPPER_10_BITS)) |
| 224 | return (buf_addr+bufsize) & UPPER_10_BITS; |
| 225 | else |
| 226 | return buf_addr; |
| 227 | } |
| 228 | |
| 229 | |
| 230 | /***************************************************** |
| 231 | * allocate_buffers |
| 232 | * |
| 233 | * Try to allocate enough memory for all requested |
| 234 | * buffers. If there is not enough free space |
| 235 | * try for less memory. |
| 236 | *****************************************************/ |
| 237 | void allocate_buffers(u32 *buf_addr, u32* total_size_kbs, |
| 238 | u32 bufsize) |
| 239 | { |
| 240 | /* Compute the minimum amount of memory guaranteed to hold all |
| 241 | MAXBUFFERS such that no buffer crosses the 4MB boundary. |
| 242 | Store this value in the variable "full_size" */ |
| 243 | |
| 244 | u32 allocator_max; |
| 245 | u32 bufs_per_chunk = (FOUR_MB / bufsize); |
| 246 | u32 filled_chunks = (MAXBUFFERS-1) / bufs_per_chunk; |
| 247 | u32 leftover_bufs = MAXBUFFERS - filled_chunks * bufs_per_chunk; |
| 248 | |
| 249 | u32 full_size = bufsize /* possibly unusable part of 1st chunk */ |
| 250 | + filled_chunks * FOUR_MB /* max # of completely filled 4mb chunks */ |
| 251 | + leftover_bufs * bufsize; /* these buffs will be in a partly filled |
| 252 | chunk at beginning or end */ |
| 253 | |
| 254 | u32 full_size_kbs = 1 + (full_size-1) / 1024; |
| 255 | u32 min_size_kbs = 2*ndevices*bufsize / 1024; |
| 256 | u32 size_kbs; |
| 257 | |
| 258 | /* Now, try to allocate full_size. If this fails, keep trying for |
| 259 | less & less memory until it succeeds. */ |
| 260 | #ifndef STANDALONE_ALLOCATOR |
| 261 | /* initialize the allocator */ |
| 262 | allocator_init(&allocator_max); |
| 263 | #endif |
| 264 | size_kbs = full_size_kbs; |
| 265 | *buf_addr = 0; |
| 266 | printk("DT3155: We would like to get: %d KB\n", full_size_kbs); |
| 267 | printk("DT3155: ...but need at least: %d KB\n", min_size_kbs); |
| 268 | printk("DT3155: ...the allocator has: %d KB\n", allocator_max); |
| 269 | size_kbs = (full_size_kbs <= allocator_max ? full_size_kbs : allocator_max); |
| 270 | if (size_kbs > min_size_kbs) { |
| 271 | if ((*buf_addr = allocator_allocate_dma(size_kbs, GFP_KERNEL)) != 0) { |
| 272 | printk("DT3155: Managed to allocate: %d KB\n", size_kbs); |
| 273 | *total_size_kbs = size_kbs; |
| 274 | return; |
| 275 | } |
| 276 | } |
| 277 | /* If we got here, the allocation failed */ |
| 278 | printk("DT3155: Allocator failed!\n"); |
| 279 | *buf_addr = 0; |
| 280 | *total_size_kbs = 0; |
| 281 | return; |
| 282 | |
| 283 | } |
| 284 | |
| 285 | |
| 286 | /***************************************************** |
| 287 | * dt3155_setup_buffers |
| 288 | * |
| 289 | * setup_buffers just puts the buffering system into |
| 290 | * a consistent state before the start of interrupts |
| 291 | * |
| 292 | * JML : it looks like all the buffers need to be |
| 293 | * continuous. So I'm going to try and allocate one |
| 294 | * continuous buffer. |
| 295 | * |
| 296 | * GCS : Fix DMA problems when buffer spans |
| 297 | * 4MB boundary. Also, add error checking. This |
| 298 | * function will return -ENOMEM when not enough memory. |
| 299 | *****************************************************/ |
| 300 | u32 dt3155_setup_buffers(u32 *allocatorAddr) |
| 301 | |
| 302 | { |
| 303 | u32 index; |
| 304 | u32 rambuff_addr; /* start of allocation */ |
| 305 | u32 rambuff_size; /* total size allocated to driver */ |
| 306 | u32 rambuff_acm; /* accumlator, keep track of how much |
| 307 | is left after being split up*/ |
| 308 | u32 rambuff_end; /* end of rambuff */ |
| 309 | u32 numbufs; /* number of useful buffers allocated (per device) */ |
| 310 | u32 bufsize = DT3155_MAX_ROWS * DT3155_MAX_COLS; |
| 311 | int m; /* minor # of device, looped for all devs */ |
| 312 | |
| 313 | /* zero the fbuffer status and address structure */ |
| 314 | for (m = 0; m < ndevices; m++) { |
| 315 | dt3155_fbuffer[m] = &(dt3155_status[m].fbuffer); |
| 316 | |
| 317 | /* Make sure the buffering variables are consistent */ |
| 318 | { |
| 319 | u8 *ptr = (u8 *) dt3155_fbuffer[m]; |
| 320 | for (index = 0; index < sizeof(struct dt3155_fbuffer); index++) |
| 321 | *(ptr++) = 0; |
| 322 | } |
| 323 | } |
| 324 | |
| 325 | /* allocate a large contiguous chunk of RAM */ |
| 326 | allocate_buffers(&rambuff_addr, &rambuff_size, bufsize); |
| 327 | printk("DT3155: mem info\n"); |
| 328 | printk(" - rambuf_addr = 0x%x\n", rambuff_addr); |
| 329 | printk(" - length (kb) = %u\n", rambuff_size); |
| 330 | if (rambuff_addr == 0) { |
| 331 | printk(KERN_INFO |
| 332 | "DT3155: Error setup_buffers() allocator dma failed\n"); |
| 333 | return -ENOMEM; |
| 334 | } |
| 335 | *allocatorAddr = rambuff_addr; |
| 336 | rambuff_end = rambuff_addr + 1024 * rambuff_size; |
| 337 | |
| 338 | /* after allocation, we need to count how many useful buffers there |
| 339 | are so we can give an equal number to each device */ |
| 340 | rambuff_acm = rambuff_addr; |
| 341 | for (index = 0; index < MAXBUFFERS; index++) { |
| 342 | rambuff_acm = adjust_4MB(rambuff_acm, bufsize);/*avoid spanning 4MB bdry*/ |
| 343 | if (rambuff_acm + bufsize > rambuff_end) |
| 344 | break; |
| 345 | rambuff_acm += bufsize; |
| 346 | } |
| 347 | /* Following line is OK, will waste buffers if index |
| 348 | * not evenly divisible by ndevices -NJC*/ |
| 349 | numbufs = index / ndevices; |
| 350 | printk(" - numbufs = %u\n", numbufs); |
| 351 | if (numbufs < 2) { |
| 352 | printk(KERN_INFO |
| 353 | "DT3155: Error setup_buffers() couldn't allocate 2 bufs/board\n"); |
| 354 | return -ENOMEM; |
| 355 | } |
| 356 | |
| 357 | /* now that we have board memory we spit it up */ |
| 358 | /* between the boards and the buffers */ |
| 359 | rambuff_acm = rambuff_addr; |
| 360 | for (m = 0; m < ndevices; m++) { |
| 361 | rambuff_acm = adjust_4MB(rambuff_acm, bufsize); |
| 362 | |
| 363 | /* Save the start of this boards buffer space (for mmap). */ |
| 364 | dt3155_status[m].mem_addr = rambuff_acm; |
| 365 | |
| 366 | for (index = 0; index < numbufs; index++) { |
| 367 | rambuff_acm = adjust_4MB(rambuff_acm, bufsize); |
| 368 | if (rambuff_acm + bufsize > rambuff_end) { |
| 369 | /* Should never happen */ |
| 370 | printk("DT3155 PROGRAM ERROR (GCS)\n" |
| 371 | "Error distributing allocated buffers\n"); |
| 372 | return -ENOMEM; |
| 373 | } |
| 374 | |
| 375 | dt3155_fbuffer[m]->frame_info[index].addr = rambuff_acm; |
| 376 | push_empty(index, m); |
| 377 | /* printk(" - Buffer : %lx\n", |
| 378 | * dt3155_fbuffer[m]->frame_info[index].addr); |
| 379 | */ |
| 380 | dt3155_fbuffer[m]->nbuffers += 1; |
| 381 | rambuff_acm += bufsize; |
| 382 | } |
| 383 | |
| 384 | /* Make sure there is an active buffer there. */ |
| 385 | dt3155_fbuffer[m]->active_buf = pop_empty(m); |
| 386 | dt3155_fbuffer[m]->even_happened = 0; |
| 387 | dt3155_fbuffer[m]->even_stopped = 0; |
| 388 | |
| 389 | /* make sure there is no locked_buf JML 2/28/00 */ |
| 390 | dt3155_fbuffer[m]->locked_buf = -1; |
| 391 | |
| 392 | dt3155_status[m].mem_size = |
| 393 | rambuff_acm - dt3155_status[m].mem_addr; |
| 394 | |
| 395 | /* setup the ready queue */ |
| 396 | dt3155_fbuffer[m]->ready_head = 0; |
| 397 | dt3155_fbuffer[m]->ready_len = 0; |
| 398 | printk("Available buffers for device %d: %d\n", |
| 399 | m, dt3155_fbuffer[m]->nbuffers); |
| 400 | } |
| 401 | |
| 402 | return 1; |
| 403 | } |
| 404 | |
| 405 | /***************************************************** |
| 406 | * internal_release_locked_buffer |
| 407 | * |
| 408 | * The internal function for releasing a locked buffer. |
| 409 | * It assumes interrupts are turned off. |
| 410 | * |
| 411 | * m is minor number of device |
| 412 | *****************************************************/ |
| 413 | static void internal_release_locked_buffer(int m) |
| 414 | { |
| 415 | /* Pointer into global structure for handling buffers */ |
| 416 | if (dt3155_fbuffer[m]->locked_buf >= 0) { |
| 417 | push_empty(dt3155_fbuffer[m]->locked_buf, m); |
| 418 | dt3155_fbuffer[m]->locked_buf = -1; |
| 419 | } |
| 420 | } |
| 421 | |
| 422 | |
| 423 | /***************************************************** |
| 424 | * dt3155_release_locked_buffer() |
| 425 | * m is minor # of device |
| 426 | * |
| 427 | * The user function of the above. |
| 428 | * |
| 429 | *****************************************************/ |
| 430 | void dt3155_release_locked_buffer(int m) |
| 431 | { |
| 432 | unsigned long int flags; |
| 433 | local_save_flags(flags); |
| 434 | local_irq_disable(); |
| 435 | internal_release_locked_buffer(m); |
| 436 | local_irq_restore(flags); |
| 437 | } |
| 438 | |
| 439 | |
| 440 | /***************************************************** |
| 441 | * dt3155_flush() |
| 442 | * m is minor # of device |
| 443 | * |
| 444 | *****************************************************/ |
| 445 | int dt3155_flush(int m) |
| 446 | { |
| 447 | int index; |
| 448 | unsigned long int flags; |
| 449 | local_save_flags(flags); |
| 450 | local_irq_disable(); |
| 451 | |
| 452 | internal_release_locked_buffer(m); |
| 453 | dt3155_fbuffer[m]->empty_len = 0; |
| 454 | |
| 455 | for (index = 0; index < dt3155_fbuffer[m]->nbuffers; index++) |
| 456 | push_empty(index, m); |
| 457 | |
| 458 | /* Make sure there is an active buffer there. */ |
| 459 | dt3155_fbuffer[m]->active_buf = pop_empty(m); |
| 460 | |
| 461 | dt3155_fbuffer[m]->even_happened = 0; |
| 462 | dt3155_fbuffer[m]->even_stopped = 0; |
| 463 | |
| 464 | /* setup the ready queue */ |
| 465 | dt3155_fbuffer[m]->ready_head = 0; |
| 466 | dt3155_fbuffer[m]->ready_len = 0; |
| 467 | |
| 468 | local_irq_restore(flags); |
| 469 | |
| 470 | return 0; |
| 471 | } |
| 472 | |
| 473 | /***************************************************** |
| 474 | * dt3155_get_ready_buffer() |
| 475 | * m is minor # of device |
| 476 | * |
| 477 | * get_ready_buffer will grab the next chunk of data |
| 478 | * if it is already there, otherwise it returns 0. |
| 479 | * If the user has a buffer locked it will unlock |
| 480 | * that buffer before returning the new one. |
| 481 | *****************************************************/ |
| 482 | int dt3155_get_ready_buffer(int m) |
| 483 | { |
| 484 | int frame_index; |
| 485 | unsigned long int flags; |
| 486 | local_save_flags(flags); |
| 487 | local_irq_disable(); |
| 488 | |
| 489 | #ifdef DEBUG_QUES_A |
| 490 | printques(m); |
| 491 | #endif |
| 492 | |
| 493 | internal_release_locked_buffer(m); |
| 494 | |
| 495 | if (is_ready_buf_empty(m)) |
| 496 | frame_index = -1; |
| 497 | else { |
| 498 | frame_index = pop_ready(m); |
| 499 | dt3155_fbuffer[m]->locked_buf = frame_index; |
| 500 | } |
| 501 | |
| 502 | #ifdef DEBUG_QUES_B |
| 503 | printques(m); |
| 504 | #endif |
| 505 | |
| 506 | local_irq_restore(flags); |
| 507 | |
| 508 | return frame_index; |
| 509 | } |