1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright 2016-17 IBM Corp. 4 */ 5 6 #define pr_fmt(fmt) "vas: " fmt 7 8 #include <linux/types.h> 9 #include <linux/mutex.h> 10 #include <linux/slab.h> 11 #include <linux/io.h> 12 #include <linux/log2.h> 13 #include <linux/rcupdate.h> 14 #include <linux/cred.h> 15 #include <linux/sched/mm.h> 16 #include <linux/mmu_context.h> 17 #include <asm/switch_to.h> 18 #include <asm/ppc-opcode.h> 19 #include <asm/vas.h> 20 #include "vas.h" 21 #include "copy-paste.h" 22 23 #define CREATE_TRACE_POINTS 24 #include "vas-trace.h" 25 26 /* 27 * Compute the paste address region for the window @window using the 28 * ->paste_base_addr and ->paste_win_id_shift we got from device tree. 29 */ 30 void vas_win_paste_addr(struct vas_window *window, u64 *addr, int *len) 31 { 32 int winid; 33 u64 base, shift; 34 35 base = window->vinst->paste_base_addr; 36 shift = window->vinst->paste_win_id_shift; 37 winid = window->winid; 38 39 *addr = base + (winid << shift); 40 if (len) 41 *len = PAGE_SIZE; 42 43 pr_debug("Txwin #%d: Paste addr 0x%llx\n", winid, *addr); 44 } 45 46 static inline void get_hvwc_mmio_bar(struct vas_window *window, 47 u64 *start, int *len) 48 { 49 u64 pbaddr; 50 51 pbaddr = window->vinst->hvwc_bar_start; 52 *start = pbaddr + window->winid * VAS_HVWC_SIZE; 53 *len = VAS_HVWC_SIZE; 54 } 55 56 static inline void get_uwc_mmio_bar(struct vas_window *window, 57 u64 *start, int *len) 58 { 59 u64 pbaddr; 60 61 pbaddr = window->vinst->uwc_bar_start; 62 *start = pbaddr + window->winid * VAS_UWC_SIZE; 63 *len = VAS_UWC_SIZE; 64 } 65 66 /* 67 * Map the paste bus address of the given send window into kernel address 68 * space. Unlike MMIO regions (map_mmio_region() below), paste region must 69 * be mapped cache-able and is only applicable to send windows. 70 */ 71 static void *map_paste_region(struct vas_window *txwin) 72 { 73 int len; 74 void *map; 75 char *name; 76 u64 start; 77 78 name = kasprintf(GFP_KERNEL, "window-v%d-w%d", txwin->vinst->vas_id, 79 txwin->winid); 80 if (!name) 81 goto free_name; 82 83 txwin->paste_addr_name = name; 84 vas_win_paste_addr(txwin, &start, &len); 85 86 if (!request_mem_region(start, len, name)) { 87 pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n", 88 __func__, start, len); 89 goto free_name; 90 } 91 92 map = ioremap_cache(start, len); 93 if (!map) { 94 pr_devel("%s(): ioremap_cache(0x%llx, %d) failed\n", __func__, 95 start, len); 96 goto free_name; 97 } 98 99 pr_devel("Mapped paste addr 0x%llx to kaddr 0x%p\n", start, map); 100 return map; 101 102 free_name: 103 kfree(name); 104 return ERR_PTR(-ENOMEM); 105 } 106 107 static void *map_mmio_region(char *name, u64 start, int len) 108 { 109 void *map; 110 111 if (!request_mem_region(start, len, name)) { 112 pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n", 113 __func__, start, len); 114 return NULL; 115 } 116 117 map = ioremap(start, len); 118 if (!map) { 119 pr_devel("%s(): ioremap(0x%llx, %d) failed\n", __func__, start, 120 len); 121 return NULL; 122 } 123 124 return map; 125 } 126 127 static void unmap_region(void *addr, u64 start, int len) 128 { 129 iounmap(addr); 130 release_mem_region((phys_addr_t)start, len); 131 } 132 133 /* 134 * Unmap the paste address region for a window. 135 */ 136 static void unmap_paste_region(struct vas_window *window) 137 { 138 int len; 139 u64 busaddr_start; 140 141 if (window->paste_kaddr) { 142 vas_win_paste_addr(window, &busaddr_start, &len); 143 unmap_region(window->paste_kaddr, busaddr_start, len); 144 window->paste_kaddr = NULL; 145 kfree(window->paste_addr_name); 146 window->paste_addr_name = NULL; 147 } 148 } 149 150 /* 151 * Unmap the MMIO regions for a window. Hold the vas_mutex so we don't 152 * unmap when the window's debugfs dir is in use. This serializes close 153 * of a window even on another VAS instance but since its not a critical 154 * path, just minimize the time we hold the mutex for now. We can add 155 * a per-instance mutex later if necessary. 156 */ 157 static void unmap_winctx_mmio_bars(struct vas_window *window) 158 { 159 int len; 160 void *uwc_map; 161 void *hvwc_map; 162 u64 busaddr_start; 163 164 mutex_lock(&vas_mutex); 165 166 hvwc_map = window->hvwc_map; 167 window->hvwc_map = NULL; 168 169 uwc_map = window->uwc_map; 170 window->uwc_map = NULL; 171 172 mutex_unlock(&vas_mutex); 173 174 if (hvwc_map) { 175 get_hvwc_mmio_bar(window, &busaddr_start, &len); 176 unmap_region(hvwc_map, busaddr_start, len); 177 } 178 179 if (uwc_map) { 180 get_uwc_mmio_bar(window, &busaddr_start, &len); 181 unmap_region(uwc_map, busaddr_start, len); 182 } 183 } 184 185 /* 186 * Find the Hypervisor Window Context (HVWC) MMIO Base Address Region and the 187 * OS/User Window Context (UWC) MMIO Base Address Region for the given window. 188 * Map these bus addresses and save the mapped kernel addresses in @window. 189 */ 190 static int map_winctx_mmio_bars(struct vas_window *window) 191 { 192 int len; 193 u64 start; 194 195 get_hvwc_mmio_bar(window, &start, &len); 196 window->hvwc_map = map_mmio_region("HVWCM_Window", start, len); 197 198 get_uwc_mmio_bar(window, &start, &len); 199 window->uwc_map = map_mmio_region("UWCM_Window", start, len); 200 201 if (!window->hvwc_map || !window->uwc_map) { 202 unmap_winctx_mmio_bars(window); 203 return -1; 204 } 205 206 return 0; 207 } 208 209 /* 210 * Reset all valid registers in the HV and OS/User Window Contexts for 211 * the window identified by @window. 212 * 213 * NOTE: We cannot really use a for loop to reset window context. Not all 214 * offsets in a window context are valid registers and the valid 215 * registers are not sequential. And, we can only write to offsets 216 * with valid registers. 217 */ 218 static void reset_window_regs(struct vas_window *window) 219 { 220 write_hvwc_reg(window, VREG(LPID), 0ULL); 221 write_hvwc_reg(window, VREG(PID), 0ULL); 222 write_hvwc_reg(window, VREG(XLATE_MSR), 0ULL); 223 write_hvwc_reg(window, VREG(XLATE_LPCR), 0ULL); 224 write_hvwc_reg(window, VREG(XLATE_CTL), 0ULL); 225 write_hvwc_reg(window, VREG(AMR), 0ULL); 226 write_hvwc_reg(window, VREG(SEIDR), 0ULL); 227 write_hvwc_reg(window, VREG(FAULT_TX_WIN), 0ULL); 228 write_hvwc_reg(window, VREG(OSU_INTR_SRC_RA), 0ULL); 229 write_hvwc_reg(window, VREG(HV_INTR_SRC_RA), 0ULL); 230 write_hvwc_reg(window, VREG(PSWID), 0ULL); 231 write_hvwc_reg(window, VREG(LFIFO_BAR), 0ULL); 232 write_hvwc_reg(window, VREG(LDATA_STAMP_CTL), 0ULL); 233 write_hvwc_reg(window, VREG(LDMA_CACHE_CTL), 0ULL); 234 write_hvwc_reg(window, VREG(LRFIFO_PUSH), 0ULL); 235 write_hvwc_reg(window, VREG(CURR_MSG_COUNT), 0ULL); 236 write_hvwc_reg(window, VREG(LNOTIFY_AFTER_COUNT), 0ULL); 237 write_hvwc_reg(window, VREG(LRX_WCRED), 0ULL); 238 write_hvwc_reg(window, VREG(LRX_WCRED_ADDER), 0ULL); 239 write_hvwc_reg(window, VREG(TX_WCRED), 0ULL); 240 write_hvwc_reg(window, VREG(TX_WCRED_ADDER), 0ULL); 241 write_hvwc_reg(window, VREG(LFIFO_SIZE), 0ULL); 242 write_hvwc_reg(window, VREG(WINCTL), 0ULL); 243 write_hvwc_reg(window, VREG(WIN_STATUS), 0ULL); 244 write_hvwc_reg(window, VREG(WIN_CTX_CACHING_CTL), 0ULL); 245 write_hvwc_reg(window, VREG(TX_RSVD_BUF_COUNT), 0ULL); 246 write_hvwc_reg(window, VREG(LRFIFO_WIN_PTR), 0ULL); 247 write_hvwc_reg(window, VREG(LNOTIFY_CTL), 0ULL); 248 write_hvwc_reg(window, VREG(LNOTIFY_PID), 0ULL); 249 write_hvwc_reg(window, VREG(LNOTIFY_LPID), 0ULL); 250 write_hvwc_reg(window, VREG(LNOTIFY_TID), 0ULL); 251 write_hvwc_reg(window, VREG(LNOTIFY_SCOPE), 0ULL); 252 write_hvwc_reg(window, VREG(NX_UTIL_ADDER), 0ULL); 253 254 /* Skip read-only registers: NX_UTIL and NX_UTIL_SE */ 255 256 /* 257 * The send and receive window credit adder registers are also 258 * accessible from HVWC and have been initialized above. We don't 259 * need to initialize from the OS/User Window Context, so skip 260 * following calls: 261 * 262 * write_uwc_reg(window, VREG(TX_WCRED_ADDER), 0ULL); 263 * write_uwc_reg(window, VREG(LRX_WCRED_ADDER), 0ULL); 264 */ 265 } 266 267 /* 268 * Initialize window context registers related to Address Translation. 269 * These registers are common to send/receive windows although they 270 * differ for user/kernel windows. As we resolve the TODOs we may 271 * want to add fields to vas_winctx and move the initialization to 272 * init_vas_winctx_regs(). 273 */ 274 static void init_xlate_regs(struct vas_window *window, bool user_win) 275 { 276 u64 lpcr, val; 277 278 /* 279 * MSR_TA, MSR_US are false for both kernel and user. 280 * MSR_DR and MSR_PR are false for kernel. 281 */ 282 val = 0ULL; 283 val = SET_FIELD(VAS_XLATE_MSR_HV, val, 1); 284 val = SET_FIELD(VAS_XLATE_MSR_SF, val, 1); 285 if (user_win) { 286 val = SET_FIELD(VAS_XLATE_MSR_DR, val, 1); 287 val = SET_FIELD(VAS_XLATE_MSR_PR, val, 1); 288 } 289 write_hvwc_reg(window, VREG(XLATE_MSR), val); 290 291 lpcr = mfspr(SPRN_LPCR); 292 val = 0ULL; 293 /* 294 * NOTE: From Section 5.7.8.1 Segment Lookaside Buffer of the 295 * Power ISA, v3.0B, Page size encoding is 0 = 4KB, 5 = 64KB. 296 * 297 * NOTE: From Section 1.3.1, Address Translation Context of the 298 * Nest MMU Workbook, LPCR_SC should be 0 for Power9. 299 */ 300 val = SET_FIELD(VAS_XLATE_LPCR_PAGE_SIZE, val, 5); 301 val = SET_FIELD(VAS_XLATE_LPCR_ISL, val, lpcr & LPCR_ISL); 302 val = SET_FIELD(VAS_XLATE_LPCR_TC, val, lpcr & LPCR_TC); 303 val = SET_FIELD(VAS_XLATE_LPCR_SC, val, 0); 304 write_hvwc_reg(window, VREG(XLATE_LPCR), val); 305 306 /* 307 * Section 1.3.1 (Address translation Context) of NMMU workbook. 308 * 0b00 Hashed Page Table mode 309 * 0b01 Reserved 310 * 0b10 Radix on HPT 311 * 0b11 Radix on Radix 312 */ 313 val = 0ULL; 314 val = SET_FIELD(VAS_XLATE_MODE, val, radix_enabled() ? 3 : 2); 315 write_hvwc_reg(window, VREG(XLATE_CTL), val); 316 317 /* 318 * TODO: Can we mfspr(AMR) even for user windows? 319 */ 320 val = 0ULL; 321 val = SET_FIELD(VAS_AMR, val, mfspr(SPRN_AMR)); 322 write_hvwc_reg(window, VREG(AMR), val); 323 324 val = 0ULL; 325 val = SET_FIELD(VAS_SEIDR, val, 0); 326 write_hvwc_reg(window, VREG(SEIDR), val); 327 } 328 329 /* 330 * Initialize Reserved Send Buffer Count for the send window. It involves 331 * writing to the register, reading it back to confirm that the hardware 332 * has enough buffers to reserve. See section 1.3.1.2.1 of VAS workbook. 333 * 334 * Since we can only make a best-effort attempt to fulfill the request, 335 * we don't return any errors if we cannot. 336 * 337 * TODO: Reserved (aka dedicated) send buffers are not supported yet. 338 */ 339 static void init_rsvd_tx_buf_count(struct vas_window *txwin, 340 struct vas_winctx *winctx) 341 { 342 write_hvwc_reg(txwin, VREG(TX_RSVD_BUF_COUNT), 0ULL); 343 } 344 345 /* 346 * init_winctx_regs() 347 * Initialize window context registers for a receive window. 348 * Except for caching control and marking window open, the registers 349 * are initialized in the order listed in Section 3.1.4 (Window Context 350 * Cache Register Details) of the VAS workbook although they don't need 351 * to be. 352 * 353 * Design note: For NX receive windows, NX allocates the FIFO buffer in OPAL 354 * (so that it can get a large contiguous area) and passes that buffer 355 * to kernel via device tree. We now write that buffer address to the 356 * FIFO BAR. Would it make sense to do this all in OPAL? i.e have OPAL 357 * write the per-chip RX FIFO addresses to the windows during boot-up 358 * as a one-time task? That could work for NX but what about other 359 * receivers? Let the receivers tell us the rx-fifo buffers for now. 360 */ 361 static void init_winctx_regs(struct vas_window *window, 362 struct vas_winctx *winctx) 363 { 364 u64 val; 365 int fifo_size; 366 367 reset_window_regs(window); 368 369 val = 0ULL; 370 val = SET_FIELD(VAS_LPID, val, winctx->lpid); 371 write_hvwc_reg(window, VREG(LPID), val); 372 373 val = 0ULL; 374 val = SET_FIELD(VAS_PID_ID, val, winctx->pidr); 375 write_hvwc_reg(window, VREG(PID), val); 376 377 init_xlate_regs(window, winctx->user_win); 378 379 val = 0ULL; 380 val = SET_FIELD(VAS_FAULT_TX_WIN, val, winctx->fault_win_id); 381 write_hvwc_reg(window, VREG(FAULT_TX_WIN), val); 382 383 /* In PowerNV, interrupts go to HV. */ 384 write_hvwc_reg(window, VREG(OSU_INTR_SRC_RA), 0ULL); 385 386 val = 0ULL; 387 val = SET_FIELD(VAS_HV_INTR_SRC_RA, val, winctx->irq_port); 388 write_hvwc_reg(window, VREG(HV_INTR_SRC_RA), val); 389 390 val = 0ULL; 391 val = SET_FIELD(VAS_PSWID_EA_HANDLE, val, winctx->pswid); 392 write_hvwc_reg(window, VREG(PSWID), val); 393 394 write_hvwc_reg(window, VREG(SPARE1), 0ULL); 395 write_hvwc_reg(window, VREG(SPARE2), 0ULL); 396 write_hvwc_reg(window, VREG(SPARE3), 0ULL); 397 398 /* 399 * NOTE: VAS expects the FIFO address to be copied into the LFIFO_BAR 400 * register as is - do NOT shift the address into VAS_LFIFO_BAR 401 * bit fields! Ok to set the page migration select fields - 402 * VAS ignores the lower 10+ bits in the address anyway, because 403 * the minimum FIFO size is 1K? 404 * 405 * See also: Design note in function header. 406 */ 407 val = __pa(winctx->rx_fifo); 408 val = SET_FIELD(VAS_PAGE_MIGRATION_SELECT, val, 0); 409 write_hvwc_reg(window, VREG(LFIFO_BAR), val); 410 411 val = 0ULL; 412 val = SET_FIELD(VAS_LDATA_STAMP, val, winctx->data_stamp); 413 write_hvwc_reg(window, VREG(LDATA_STAMP_CTL), val); 414 415 val = 0ULL; 416 val = SET_FIELD(VAS_LDMA_TYPE, val, winctx->dma_type); 417 val = SET_FIELD(VAS_LDMA_FIFO_DISABLE, val, winctx->fifo_disable); 418 write_hvwc_reg(window, VREG(LDMA_CACHE_CTL), val); 419 420 write_hvwc_reg(window, VREG(LRFIFO_PUSH), 0ULL); 421 write_hvwc_reg(window, VREG(CURR_MSG_COUNT), 0ULL); 422 write_hvwc_reg(window, VREG(LNOTIFY_AFTER_COUNT), 0ULL); 423 424 val = 0ULL; 425 val = SET_FIELD(VAS_LRX_WCRED, val, winctx->wcreds_max); 426 write_hvwc_reg(window, VREG(LRX_WCRED), val); 427 428 val = 0ULL; 429 val = SET_FIELD(VAS_TX_WCRED, val, winctx->wcreds_max); 430 write_hvwc_reg(window, VREG(TX_WCRED), val); 431 432 write_hvwc_reg(window, VREG(LRX_WCRED_ADDER), 0ULL); 433 write_hvwc_reg(window, VREG(TX_WCRED_ADDER), 0ULL); 434 435 fifo_size = winctx->rx_fifo_size / 1024; 436 437 val = 0ULL; 438 val = SET_FIELD(VAS_LFIFO_SIZE, val, ilog2(fifo_size)); 439 write_hvwc_reg(window, VREG(LFIFO_SIZE), val); 440 441 /* Update window control and caching control registers last so 442 * we mark the window open only after fully initializing it and 443 * pushing context to cache. 444 */ 445 446 write_hvwc_reg(window, VREG(WIN_STATUS), 0ULL); 447 448 init_rsvd_tx_buf_count(window, winctx); 449 450 /* for a send window, point to the matching receive window */ 451 val = 0ULL; 452 val = SET_FIELD(VAS_LRX_WIN_ID, val, winctx->rx_win_id); 453 write_hvwc_reg(window, VREG(LRFIFO_WIN_PTR), val); 454 455 write_hvwc_reg(window, VREG(SPARE4), 0ULL); 456 457 val = 0ULL; 458 val = SET_FIELD(VAS_NOTIFY_DISABLE, val, winctx->notify_disable); 459 val = SET_FIELD(VAS_INTR_DISABLE, val, winctx->intr_disable); 460 val = SET_FIELD(VAS_NOTIFY_EARLY, val, winctx->notify_early); 461 val = SET_FIELD(VAS_NOTIFY_OSU_INTR, val, winctx->notify_os_intr_reg); 462 write_hvwc_reg(window, VREG(LNOTIFY_CTL), val); 463 464 val = 0ULL; 465 val = SET_FIELD(VAS_LNOTIFY_PID, val, winctx->lnotify_pid); 466 write_hvwc_reg(window, VREG(LNOTIFY_PID), val); 467 468 val = 0ULL; 469 val = SET_FIELD(VAS_LNOTIFY_LPID, val, winctx->lnotify_lpid); 470 write_hvwc_reg(window, VREG(LNOTIFY_LPID), val); 471 472 val = 0ULL; 473 val = SET_FIELD(VAS_LNOTIFY_TID, val, winctx->lnotify_tid); 474 write_hvwc_reg(window, VREG(LNOTIFY_TID), val); 475 476 val = 0ULL; 477 val = SET_FIELD(VAS_LNOTIFY_MIN_SCOPE, val, winctx->min_scope); 478 val = SET_FIELD(VAS_LNOTIFY_MAX_SCOPE, val, winctx->max_scope); 479 write_hvwc_reg(window, VREG(LNOTIFY_SCOPE), val); 480 481 /* Skip read-only registers NX_UTIL and NX_UTIL_SE */ 482 483 write_hvwc_reg(window, VREG(SPARE5), 0ULL); 484 write_hvwc_reg(window, VREG(NX_UTIL_ADDER), 0ULL); 485 write_hvwc_reg(window, VREG(SPARE6), 0ULL); 486 487 /* Finally, push window context to memory and... */ 488 val = 0ULL; 489 val = SET_FIELD(VAS_PUSH_TO_MEM, val, 1); 490 write_hvwc_reg(window, VREG(WIN_CTX_CACHING_CTL), val); 491 492 /* ... mark the window open for business */ 493 val = 0ULL; 494 val = SET_FIELD(VAS_WINCTL_REJ_NO_CREDIT, val, winctx->rej_no_credit); 495 val = SET_FIELD(VAS_WINCTL_PIN, val, winctx->pin_win); 496 val = SET_FIELD(VAS_WINCTL_TX_WCRED_MODE, val, winctx->tx_wcred_mode); 497 val = SET_FIELD(VAS_WINCTL_RX_WCRED_MODE, val, winctx->rx_wcred_mode); 498 val = SET_FIELD(VAS_WINCTL_TX_WORD_MODE, val, winctx->tx_word_mode); 499 val = SET_FIELD(VAS_WINCTL_RX_WORD_MODE, val, winctx->rx_word_mode); 500 val = SET_FIELD(VAS_WINCTL_FAULT_WIN, val, winctx->fault_win); 501 val = SET_FIELD(VAS_WINCTL_NX_WIN, val, winctx->nx_win); 502 val = SET_FIELD(VAS_WINCTL_OPEN, val, 1); 503 write_hvwc_reg(window, VREG(WINCTL), val); 504 } 505 506 static void vas_release_window_id(struct ida *ida, int winid) 507 { 508 ida_free(ida, winid); 509 } 510 511 static int vas_assign_window_id(struct ida *ida) 512 { 513 int winid = ida_alloc_max(ida, VAS_WINDOWS_PER_CHIP - 1, GFP_KERNEL); 514 515 if (winid == -ENOSPC) { 516 pr_err("Too many (%d) open windows\n", VAS_WINDOWS_PER_CHIP); 517 return -EAGAIN; 518 } 519 520 return winid; 521 } 522 523 static void vas_window_free(struct vas_window *window) 524 { 525 int winid = window->winid; 526 struct vas_instance *vinst = window->vinst; 527 528 unmap_winctx_mmio_bars(window); 529 530 vas_window_free_dbgdir(window); 531 532 kfree(window); 533 534 vas_release_window_id(&vinst->ida, winid); 535 } 536 537 static struct vas_window *vas_window_alloc(struct vas_instance *vinst) 538 { 539 int winid; 540 struct vas_window *window; 541 542 winid = vas_assign_window_id(&vinst->ida); 543 if (winid < 0) 544 return ERR_PTR(winid); 545 546 window = kzalloc(sizeof(*window), GFP_KERNEL); 547 if (!window) 548 goto out_free; 549 550 window->vinst = vinst; 551 window->winid = winid; 552 553 if (map_winctx_mmio_bars(window)) 554 goto out_free; 555 556 vas_window_init_dbgdir(window); 557 558 return window; 559 560 out_free: 561 kfree(window); 562 vas_release_window_id(&vinst->ida, winid); 563 return ERR_PTR(-ENOMEM); 564 } 565 566 static void put_rx_win(struct vas_window *rxwin) 567 { 568 /* Better not be a send window! */ 569 WARN_ON_ONCE(rxwin->tx_win); 570 571 atomic_dec(&rxwin->num_txwins); 572 } 573 574 /* 575 * Find the user space receive window given the @pswid. 576 * - We must have a valid vasid and it must belong to this instance. 577 * (so both send and receive windows are on the same VAS instance) 578 * - The window must refer to an OPEN, FTW, RECEIVE window. 579 * 580 * NOTE: We access ->windows[] table and assume that vinst->mutex is held. 581 */ 582 static struct vas_window *get_user_rxwin(struct vas_instance *vinst, u32 pswid) 583 { 584 int vasid, winid; 585 struct vas_window *rxwin; 586 587 decode_pswid(pswid, &vasid, &winid); 588 589 if (vinst->vas_id != vasid) 590 return ERR_PTR(-EINVAL); 591 592 rxwin = vinst->windows[winid]; 593 594 if (!rxwin || rxwin->tx_win || rxwin->cop != VAS_COP_TYPE_FTW) 595 return ERR_PTR(-EINVAL); 596 597 return rxwin; 598 } 599 600 /* 601 * Get the VAS receive window associated with NX engine identified 602 * by @cop and if applicable, @pswid. 603 * 604 * See also function header of set_vinst_win(). 605 */ 606 static struct vas_window *get_vinst_rxwin(struct vas_instance *vinst, 607 enum vas_cop_type cop, u32 pswid) 608 { 609 struct vas_window *rxwin; 610 611 mutex_lock(&vinst->mutex); 612 613 if (cop == VAS_COP_TYPE_FTW) 614 rxwin = get_user_rxwin(vinst, pswid); 615 else 616 rxwin = vinst->rxwin[cop] ?: ERR_PTR(-EINVAL); 617 618 if (!IS_ERR(rxwin)) 619 atomic_inc(&rxwin->num_txwins); 620 621 mutex_unlock(&vinst->mutex); 622 623 return rxwin; 624 } 625 626 /* 627 * We have two tables of windows in a VAS instance. The first one, 628 * ->windows[], contains all the windows in the instance and allows 629 * looking up a window by its id. It is used to look up send windows 630 * during fault handling and receive windows when pairing user space 631 * send/receive windows. 632 * 633 * The second table, ->rxwin[], contains receive windows that are 634 * associated with NX engines. This table has VAS_COP_TYPE_MAX 635 * entries and is used to look up a receive window by its 636 * coprocessor type. 637 * 638 * Here, we save @window in the ->windows[] table. If it is a receive 639 * window, we also save the window in the ->rxwin[] table. 640 */ 641 static void set_vinst_win(struct vas_instance *vinst, 642 struct vas_window *window) 643 { 644 int id = window->winid; 645 646 mutex_lock(&vinst->mutex); 647 648 /* 649 * There should only be one receive window for a coprocessor type 650 * unless its a user (FTW) window. 651 */ 652 if (!window->user_win && !window->tx_win) { 653 WARN_ON_ONCE(vinst->rxwin[window->cop]); 654 vinst->rxwin[window->cop] = window; 655 } 656 657 WARN_ON_ONCE(vinst->windows[id] != NULL); 658 vinst->windows[id] = window; 659 660 mutex_unlock(&vinst->mutex); 661 } 662 663 /* 664 * Clear this window from the table(s) of windows for this VAS instance. 665 * See also function header of set_vinst_win(). 666 */ 667 static void clear_vinst_win(struct vas_window *window) 668 { 669 int id = window->winid; 670 struct vas_instance *vinst = window->vinst; 671 672 mutex_lock(&vinst->mutex); 673 674 if (!window->user_win && !window->tx_win) { 675 WARN_ON_ONCE(!vinst->rxwin[window->cop]); 676 vinst->rxwin[window->cop] = NULL; 677 } 678 679 WARN_ON_ONCE(vinst->windows[id] != window); 680 vinst->windows[id] = NULL; 681 682 mutex_unlock(&vinst->mutex); 683 } 684 685 static void init_winctx_for_rxwin(struct vas_window *rxwin, 686 struct vas_rx_win_attr *rxattr, 687 struct vas_winctx *winctx) 688 { 689 /* 690 * We first zero (memset()) all fields and only set non-zero fields. 691 * Following fields are 0/false but maybe deserve a comment: 692 * 693 * ->notify_os_intr_reg In powerNV, send intrs to HV 694 * ->notify_disable False for NX windows 695 * ->intr_disable False for Fault Windows 696 * ->xtra_write False for NX windows 697 * ->notify_early NA for NX windows 698 * ->rsvd_txbuf_count NA for Rx windows 699 * ->lpid, ->pid, ->tid NA for Rx windows 700 */ 701 702 memset(winctx, 0, sizeof(struct vas_winctx)); 703 704 winctx->rx_fifo = rxattr->rx_fifo; 705 winctx->rx_fifo_size = rxattr->rx_fifo_size; 706 winctx->wcreds_max = rxwin->wcreds_max; 707 winctx->pin_win = rxattr->pin_win; 708 709 winctx->nx_win = rxattr->nx_win; 710 winctx->fault_win = rxattr->fault_win; 711 winctx->user_win = rxattr->user_win; 712 winctx->rej_no_credit = rxattr->rej_no_credit; 713 winctx->rx_word_mode = rxattr->rx_win_ord_mode; 714 winctx->tx_word_mode = rxattr->tx_win_ord_mode; 715 winctx->rx_wcred_mode = rxattr->rx_wcred_mode; 716 winctx->tx_wcred_mode = rxattr->tx_wcred_mode; 717 winctx->notify_early = rxattr->notify_early; 718 719 if (winctx->nx_win) { 720 winctx->data_stamp = true; 721 winctx->intr_disable = true; 722 winctx->pin_win = true; 723 724 WARN_ON_ONCE(winctx->fault_win); 725 WARN_ON_ONCE(!winctx->rx_word_mode); 726 WARN_ON_ONCE(!winctx->tx_word_mode); 727 WARN_ON_ONCE(winctx->notify_after_count); 728 } else if (winctx->fault_win) { 729 winctx->notify_disable = true; 730 } else if (winctx->user_win) { 731 /* 732 * Section 1.8.1 Low Latency Core-Core Wake up of 733 * the VAS workbook: 734 * 735 * - disable credit checks ([tr]x_wcred_mode = false) 736 * - disable FIFO writes 737 * - enable ASB_Notify, disable interrupt 738 */ 739 winctx->fifo_disable = true; 740 winctx->intr_disable = true; 741 winctx->rx_fifo = NULL; 742 } 743 744 winctx->lnotify_lpid = rxattr->lnotify_lpid; 745 winctx->lnotify_pid = rxattr->lnotify_pid; 746 winctx->lnotify_tid = rxattr->lnotify_tid; 747 winctx->pswid = rxattr->pswid; 748 winctx->dma_type = VAS_DMA_TYPE_INJECT; 749 winctx->tc_mode = rxattr->tc_mode; 750 751 winctx->min_scope = VAS_SCOPE_LOCAL; 752 winctx->max_scope = VAS_SCOPE_VECTORED_GROUP; 753 if (rxwin->vinst->virq) 754 winctx->irq_port = rxwin->vinst->irq_port; 755 } 756 757 static bool rx_win_args_valid(enum vas_cop_type cop, 758 struct vas_rx_win_attr *attr) 759 { 760 pr_debug("Rxattr: fault %d, notify %d, intr %d, early %d, fifo %d\n", 761 attr->fault_win, attr->notify_disable, 762 attr->intr_disable, attr->notify_early, 763 attr->rx_fifo_size); 764 765 if (cop >= VAS_COP_TYPE_MAX) 766 return false; 767 768 if (cop != VAS_COP_TYPE_FTW && 769 attr->rx_fifo_size < VAS_RX_FIFO_SIZE_MIN) 770 return false; 771 772 if (attr->rx_fifo_size > VAS_RX_FIFO_SIZE_MAX) 773 return false; 774 775 if (!attr->wcreds_max) 776 return false; 777 778 if (attr->nx_win) { 779 /* cannot be fault or user window if it is nx */ 780 if (attr->fault_win || attr->user_win) 781 return false; 782 /* 783 * Section 3.1.4.32: NX Windows must not disable notification, 784 * and must not enable interrupts or early notification. 785 */ 786 if (attr->notify_disable || !attr->intr_disable || 787 attr->notify_early) 788 return false; 789 } else if (attr->fault_win) { 790 /* cannot be both fault and user window */ 791 if (attr->user_win) 792 return false; 793 794 /* 795 * Section 3.1.4.32: Fault windows must disable notification 796 * but not interrupts. 797 */ 798 if (!attr->notify_disable || attr->intr_disable) 799 return false; 800 801 } else if (attr->user_win) { 802 /* 803 * User receive windows are only for fast-thread-wakeup 804 * (FTW). They don't need a FIFO and must disable interrupts 805 */ 806 if (attr->rx_fifo || attr->rx_fifo_size || !attr->intr_disable) 807 return false; 808 } else { 809 /* Rx window must be one of NX or Fault or User window. */ 810 return false; 811 } 812 813 return true; 814 } 815 816 void vas_init_rx_win_attr(struct vas_rx_win_attr *rxattr, enum vas_cop_type cop) 817 { 818 memset(rxattr, 0, sizeof(*rxattr)); 819 820 if (cop == VAS_COP_TYPE_842 || cop == VAS_COP_TYPE_842_HIPRI || 821 cop == VAS_COP_TYPE_GZIP || cop == VAS_COP_TYPE_GZIP_HIPRI) { 822 rxattr->pin_win = true; 823 rxattr->nx_win = true; 824 rxattr->fault_win = false; 825 rxattr->intr_disable = true; 826 rxattr->rx_wcred_mode = true; 827 rxattr->tx_wcred_mode = true; 828 rxattr->rx_win_ord_mode = true; 829 rxattr->tx_win_ord_mode = true; 830 } else if (cop == VAS_COP_TYPE_FAULT) { 831 rxattr->pin_win = true; 832 rxattr->fault_win = true; 833 rxattr->notify_disable = true; 834 rxattr->rx_wcred_mode = true; 835 rxattr->rx_win_ord_mode = true; 836 rxattr->rej_no_credit = true; 837 rxattr->tc_mode = VAS_THRESH_DISABLED; 838 } else if (cop == VAS_COP_TYPE_FTW) { 839 rxattr->user_win = true; 840 rxattr->intr_disable = true; 841 842 /* 843 * As noted in the VAS Workbook we disable credit checks. 844 * If we enable credit checks in the future, we must also 845 * implement a mechanism to return the user credits or new 846 * paste operations will fail. 847 */ 848 } 849 } 850 EXPORT_SYMBOL_GPL(vas_init_rx_win_attr); 851 852 struct vas_window *vas_rx_win_open(int vasid, enum vas_cop_type cop, 853 struct vas_rx_win_attr *rxattr) 854 { 855 struct vas_window *rxwin; 856 struct vas_winctx winctx; 857 struct vas_instance *vinst; 858 859 trace_vas_rx_win_open(current, vasid, cop, rxattr); 860 861 if (!rx_win_args_valid(cop, rxattr)) 862 return ERR_PTR(-EINVAL); 863 864 vinst = find_vas_instance(vasid); 865 if (!vinst) { 866 pr_devel("vasid %d not found!\n", vasid); 867 return ERR_PTR(-EINVAL); 868 } 869 pr_devel("Found instance %d\n", vasid); 870 871 rxwin = vas_window_alloc(vinst); 872 if (IS_ERR(rxwin)) { 873 pr_devel("Unable to allocate memory for Rx window\n"); 874 return rxwin; 875 } 876 877 rxwin->tx_win = false; 878 rxwin->nx_win = rxattr->nx_win; 879 rxwin->user_win = rxattr->user_win; 880 rxwin->cop = cop; 881 rxwin->wcreds_max = rxattr->wcreds_max; 882 883 init_winctx_for_rxwin(rxwin, rxattr, &winctx); 884 init_winctx_regs(rxwin, &winctx); 885 886 set_vinst_win(vinst, rxwin); 887 888 return rxwin; 889 } 890 EXPORT_SYMBOL_GPL(vas_rx_win_open); 891 892 void vas_init_tx_win_attr(struct vas_tx_win_attr *txattr, enum vas_cop_type cop) 893 { 894 memset(txattr, 0, sizeof(*txattr)); 895 896 if (cop == VAS_COP_TYPE_842 || cop == VAS_COP_TYPE_842_HIPRI || 897 cop == VAS_COP_TYPE_GZIP || cop == VAS_COP_TYPE_GZIP_HIPRI) { 898 txattr->rej_no_credit = false; 899 txattr->rx_wcred_mode = true; 900 txattr->tx_wcred_mode = true; 901 txattr->rx_win_ord_mode = true; 902 txattr->tx_win_ord_mode = true; 903 } else if (cop == VAS_COP_TYPE_FTW) { 904 txattr->user_win = true; 905 } 906 } 907 EXPORT_SYMBOL_GPL(vas_init_tx_win_attr); 908 909 static void init_winctx_for_txwin(struct vas_window *txwin, 910 struct vas_tx_win_attr *txattr, 911 struct vas_winctx *winctx) 912 { 913 /* 914 * We first zero all fields and only set non-zero ones. Following 915 * are some fields set to 0/false for the stated reason: 916 * 917 * ->notify_os_intr_reg In powernv, send intrs to HV 918 * ->rsvd_txbuf_count Not supported yet. 919 * ->notify_disable False for NX windows 920 * ->xtra_write False for NX windows 921 * ->notify_early NA for NX windows 922 * ->lnotify_lpid NA for Tx windows 923 * ->lnotify_pid NA for Tx windows 924 * ->lnotify_tid NA for Tx windows 925 * ->tx_win_cred_mode Ignore for now for NX windows 926 * ->rx_win_cred_mode Ignore for now for NX windows 927 */ 928 memset(winctx, 0, sizeof(struct vas_winctx)); 929 930 winctx->wcreds_max = txwin->wcreds_max; 931 932 winctx->user_win = txattr->user_win; 933 winctx->nx_win = txwin->rxwin->nx_win; 934 winctx->pin_win = txattr->pin_win; 935 winctx->rej_no_credit = txattr->rej_no_credit; 936 winctx->rsvd_txbuf_enable = txattr->rsvd_txbuf_enable; 937 938 winctx->rx_wcred_mode = txattr->rx_wcred_mode; 939 winctx->tx_wcred_mode = txattr->tx_wcred_mode; 940 winctx->rx_word_mode = txattr->rx_win_ord_mode; 941 winctx->tx_word_mode = txattr->tx_win_ord_mode; 942 winctx->rsvd_txbuf_count = txattr->rsvd_txbuf_count; 943 944 winctx->intr_disable = true; 945 if (winctx->nx_win) 946 winctx->data_stamp = true; 947 948 winctx->lpid = txattr->lpid; 949 winctx->pidr = txattr->pidr; 950 winctx->rx_win_id = txwin->rxwin->winid; 951 /* 952 * IRQ and fault window setup is successful. Set fault window 953 * for the send window so that ready to handle faults. 954 */ 955 if (txwin->vinst->virq) 956 winctx->fault_win_id = txwin->vinst->fault_win->winid; 957 958 winctx->dma_type = VAS_DMA_TYPE_INJECT; 959 winctx->tc_mode = txattr->tc_mode; 960 winctx->min_scope = VAS_SCOPE_LOCAL; 961 winctx->max_scope = VAS_SCOPE_VECTORED_GROUP; 962 if (txwin->vinst->virq) 963 winctx->irq_port = txwin->vinst->irq_port; 964 965 winctx->pswid = txattr->pswid ? txattr->pswid : 966 encode_pswid(txwin->vinst->vas_id, txwin->winid); 967 } 968 969 static bool tx_win_args_valid(enum vas_cop_type cop, 970 struct vas_tx_win_attr *attr) 971 { 972 if (attr->tc_mode != VAS_THRESH_DISABLED) 973 return false; 974 975 if (cop > VAS_COP_TYPE_MAX) 976 return false; 977 978 if (attr->wcreds_max > VAS_TX_WCREDS_MAX) 979 return false; 980 981 if (attr->user_win) { 982 if (attr->rsvd_txbuf_count) 983 return false; 984 985 if (cop != VAS_COP_TYPE_FTW && cop != VAS_COP_TYPE_GZIP && 986 cop != VAS_COP_TYPE_GZIP_HIPRI) 987 return false; 988 } 989 990 return true; 991 } 992 993 struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop, 994 struct vas_tx_win_attr *attr) 995 { 996 int rc; 997 struct vas_window *txwin; 998 struct vas_window *rxwin; 999 struct vas_winctx winctx; 1000 struct vas_instance *vinst; 1001 1002 trace_vas_tx_win_open(current, vasid, cop, attr); 1003 1004 if (!tx_win_args_valid(cop, attr)) 1005 return ERR_PTR(-EINVAL); 1006 1007 /* 1008 * If caller did not specify a vasid but specified the PSWID of a 1009 * receive window (applicable only to FTW windows), use the vasid 1010 * from that receive window. 1011 */ 1012 if (vasid == -1 && attr->pswid) 1013 decode_pswid(attr->pswid, &vasid, NULL); 1014 1015 vinst = find_vas_instance(vasid); 1016 if (!vinst) { 1017 pr_devel("vasid %d not found!\n", vasid); 1018 return ERR_PTR(-EINVAL); 1019 } 1020 1021 rxwin = get_vinst_rxwin(vinst, cop, attr->pswid); 1022 if (IS_ERR(rxwin)) { 1023 pr_devel("No RxWin for vasid %d, cop %d\n", vasid, cop); 1024 return rxwin; 1025 } 1026 1027 txwin = vas_window_alloc(vinst); 1028 if (IS_ERR(txwin)) { 1029 rc = PTR_ERR(txwin); 1030 goto put_rxwin; 1031 } 1032 1033 txwin->cop = cop; 1034 txwin->tx_win = 1; 1035 txwin->rxwin = rxwin; 1036 txwin->nx_win = txwin->rxwin->nx_win; 1037 txwin->user_win = attr->user_win; 1038 txwin->wcreds_max = attr->wcreds_max ?: VAS_WCREDS_DEFAULT; 1039 1040 init_winctx_for_txwin(txwin, attr, &winctx); 1041 1042 init_winctx_regs(txwin, &winctx); 1043 1044 /* 1045 * If its a kernel send window, map the window address into the 1046 * kernel's address space. For user windows, user must issue an 1047 * mmap() to map the window into their address space. 1048 * 1049 * NOTE: If kernel ever resubmits a user CRB after handling a page 1050 * fault, we will need to map this into kernel as well. 1051 */ 1052 if (!txwin->user_win) { 1053 txwin->paste_kaddr = map_paste_region(txwin); 1054 if (IS_ERR(txwin->paste_kaddr)) { 1055 rc = PTR_ERR(txwin->paste_kaddr); 1056 goto free_window; 1057 } 1058 } else { 1059 /* 1060 * Interrupt hanlder or fault window setup failed. Means 1061 * NX can not generate fault for page fault. So not 1062 * opening for user space tx window. 1063 */ 1064 if (!vinst->virq) { 1065 rc = -ENODEV; 1066 goto free_window; 1067 } 1068 rc = get_vas_user_win_ref(&txwin->task_ref); 1069 if (rc) 1070 goto free_window; 1071 1072 vas_user_win_add_mm_context(&txwin->task_ref); 1073 } 1074 1075 set_vinst_win(vinst, txwin); 1076 1077 return txwin; 1078 1079 free_window: 1080 vas_window_free(txwin); 1081 1082 put_rxwin: 1083 put_rx_win(rxwin); 1084 return ERR_PTR(rc); 1085 1086 } 1087 EXPORT_SYMBOL_GPL(vas_tx_win_open); 1088 1089 int vas_copy_crb(void *crb, int offset) 1090 { 1091 return vas_copy(crb, offset); 1092 } 1093 EXPORT_SYMBOL_GPL(vas_copy_crb); 1094 1095 #define RMA_LSMP_REPORT_ENABLE PPC_BIT(53) 1096 int vas_paste_crb(struct vas_window *txwin, int offset, bool re) 1097 { 1098 int rc; 1099 void *addr; 1100 uint64_t val; 1101 1102 trace_vas_paste_crb(current, txwin); 1103 1104 /* 1105 * Only NX windows are supported for now and hardware assumes 1106 * report-enable flag is set for NX windows. Ensure software 1107 * complies too. 1108 */ 1109 WARN_ON_ONCE(txwin->nx_win && !re); 1110 1111 addr = txwin->paste_kaddr; 1112 if (re) { 1113 /* 1114 * Set the REPORT_ENABLE bit (equivalent to writing 1115 * to 1K offset of the paste address) 1116 */ 1117 val = SET_FIELD(RMA_LSMP_REPORT_ENABLE, 0ULL, 1); 1118 addr += val; 1119 } 1120 1121 /* 1122 * Map the raw CR value from vas_paste() to an error code (there 1123 * is just pass or fail for now though). 1124 */ 1125 rc = vas_paste(addr, offset); 1126 if (rc == 2) 1127 rc = 0; 1128 else 1129 rc = -EINVAL; 1130 1131 pr_debug("Txwin #%d: Msg count %llu\n", txwin->winid, 1132 read_hvwc_reg(txwin, VREG(LRFIFO_PUSH))); 1133 1134 return rc; 1135 } 1136 EXPORT_SYMBOL_GPL(vas_paste_crb); 1137 1138 /* 1139 * If credit checking is enabled for this window, poll for the return 1140 * of window credits (i.e for NX engines to process any outstanding CRBs). 1141 * Since NX-842 waits for the CRBs to be processed before closing the 1142 * window, we should not have to wait for too long. 1143 * 1144 * TODO: We retry in 10ms intervals now. We could/should probably peek at 1145 * the VAS_LRFIFO_PUSH_OFFSET register to get an estimate of pending 1146 * CRBs on the FIFO and compute the delay dynamically on each retry. 1147 * But that is not really needed until we support NX-GZIP access from 1148 * user space. (NX-842 driver waits for CSB and Fast thread-wakeup 1149 * doesn't use credit checking). 1150 */ 1151 static void poll_window_credits(struct vas_window *window) 1152 { 1153 u64 val; 1154 int creds, mode; 1155 int count = 0; 1156 1157 val = read_hvwc_reg(window, VREG(WINCTL)); 1158 if (window->tx_win) 1159 mode = GET_FIELD(VAS_WINCTL_TX_WCRED_MODE, val); 1160 else 1161 mode = GET_FIELD(VAS_WINCTL_RX_WCRED_MODE, val); 1162 1163 if (!mode) 1164 return; 1165 retry: 1166 if (window->tx_win) { 1167 val = read_hvwc_reg(window, VREG(TX_WCRED)); 1168 creds = GET_FIELD(VAS_TX_WCRED, val); 1169 } else { 1170 val = read_hvwc_reg(window, VREG(LRX_WCRED)); 1171 creds = GET_FIELD(VAS_LRX_WCRED, val); 1172 } 1173 1174 /* 1175 * Takes around few milliseconds to complete all pending requests 1176 * and return credits. 1177 * TODO: Scan fault FIFO and invalidate CRBs points to this window 1178 * and issue CRB Kill to stop all pending requests. Need only 1179 * if there is a bug in NX or fault handling in kernel. 1180 */ 1181 if (creds < window->wcreds_max) { 1182 val = 0; 1183 set_current_state(TASK_UNINTERRUPTIBLE); 1184 schedule_timeout(msecs_to_jiffies(10)); 1185 count++; 1186 /* 1187 * Process can not close send window until all credits are 1188 * returned. 1189 */ 1190 if (!(count % 1000)) 1191 pr_warn_ratelimited("VAS: pid %d stuck. Waiting for credits returned for Window(%d). creds %d, Retries %d\n", 1192 vas_window_pid(window), window->winid, 1193 creds, count); 1194 1195 goto retry; 1196 } 1197 } 1198 1199 /* 1200 * Wait for the window to go to "not-busy" state. It should only take a 1201 * short time to queue a CRB, so window should not be busy for too long. 1202 * Trying 5ms intervals. 1203 */ 1204 static void poll_window_busy_state(struct vas_window *window) 1205 { 1206 int busy; 1207 u64 val; 1208 int count = 0; 1209 1210 retry: 1211 val = read_hvwc_reg(window, VREG(WIN_STATUS)); 1212 busy = GET_FIELD(VAS_WIN_BUSY, val); 1213 if (busy) { 1214 val = 0; 1215 set_current_state(TASK_UNINTERRUPTIBLE); 1216 schedule_timeout(msecs_to_jiffies(10)); 1217 count++; 1218 /* 1219 * Takes around few milliseconds to process all pending 1220 * requests. 1221 */ 1222 if (!(count % 1000)) 1223 pr_warn_ratelimited("VAS: pid %d stuck. Window (ID=%d) is in busy state. Retries %d\n", 1224 vas_window_pid(window), window->winid, count); 1225 1226 goto retry; 1227 } 1228 } 1229 1230 /* 1231 * Have the hardware cast a window out of cache and wait for it to 1232 * be completed. 1233 * 1234 * NOTE: It can take a relatively long time to cast the window context 1235 * out of the cache. It is not strictly necessary to cast out if: 1236 * 1237 * - we clear the "Pin Window" bit (so hardware is free to evict) 1238 * 1239 * - we re-initialize the window context when it is reassigned. 1240 * 1241 * We do the former in vas_win_close() and latter in vas_win_open(). 1242 * So, ignoring the cast-out for now. We can add it as needed. If 1243 * casting out becomes necessary we should consider offloading the 1244 * job to a worker thread, so the window close can proceed quickly. 1245 */ 1246 static void poll_window_castout(struct vas_window *window) 1247 { 1248 /* stub for now */ 1249 } 1250 1251 /* 1252 * Unpin and close a window so no new requests are accepted and the 1253 * hardware can evict this window from cache if necessary. 1254 */ 1255 static void unpin_close_window(struct vas_window *window) 1256 { 1257 u64 val; 1258 1259 val = read_hvwc_reg(window, VREG(WINCTL)); 1260 val = SET_FIELD(VAS_WINCTL_PIN, val, 0); 1261 val = SET_FIELD(VAS_WINCTL_OPEN, val, 0); 1262 write_hvwc_reg(window, VREG(WINCTL), val); 1263 } 1264 1265 /* 1266 * Close a window. 1267 * 1268 * See Section 1.12.1 of VAS workbook v1.05 for details on closing window: 1269 * - Disable new paste operations (unmap paste address) 1270 * - Poll for the "Window Busy" bit to be cleared 1271 * - Clear the Open/Enable bit for the Window. 1272 * - Poll for return of window Credits (implies FIFO empty for Rx win?) 1273 * - Unpin and cast window context out of cache 1274 * 1275 * Besides the hardware, kernel has some bookkeeping of course. 1276 */ 1277 int vas_win_close(struct vas_window *window) 1278 { 1279 if (!window) 1280 return 0; 1281 1282 if (!window->tx_win && atomic_read(&window->num_txwins) != 0) { 1283 pr_devel("Attempting to close an active Rx window!\n"); 1284 WARN_ON_ONCE(1); 1285 return -EBUSY; 1286 } 1287 1288 unmap_paste_region(window); 1289 1290 poll_window_busy_state(window); 1291 1292 unpin_close_window(window); 1293 1294 poll_window_credits(window); 1295 1296 clear_vinst_win(window); 1297 1298 poll_window_castout(window); 1299 1300 /* if send window, drop reference to matching receive window */ 1301 if (window->tx_win) { 1302 if (window->user_win) { 1303 put_vas_user_win_ref(&window->task_ref); 1304 mm_context_remove_vas_window(window->task_ref.mm); 1305 } 1306 put_rx_win(window->rxwin); 1307 } 1308 1309 vas_window_free(window); 1310 1311 return 0; 1312 } 1313 EXPORT_SYMBOL_GPL(vas_win_close); 1314 1315 /* 1316 * Return credit for the given window. 1317 * Send windows and fault window uses credit mechanism as follows: 1318 * 1319 * Send windows: 1320 * - The default number of credits available for each send window is 1321 * 1024. It means 1024 requests can be issued asynchronously at the 1322 * same time. If the credit is not available, that request will be 1323 * returned with RMA_Busy. 1324 * - One credit is taken when NX request is issued. 1325 * - This credit is returned after NX processed that request. 1326 * - If NX encounters translation error, kernel will return the 1327 * credit on the specific send window after processing the fault CRB. 1328 * 1329 * Fault window: 1330 * - The total number credits available is FIFO_SIZE/CRB_SIZE. 1331 * Means 4MB/128 in the current implementation. If credit is not 1332 * available, RMA_Reject is returned. 1333 * - A credit is taken when NX pastes CRB in fault FIFO. 1334 * - The kernel with return credit on fault window after reading entry 1335 * from fault FIFO. 1336 */ 1337 void vas_return_credit(struct vas_window *window, bool tx) 1338 { 1339 uint64_t val; 1340 1341 val = 0ULL; 1342 if (tx) { /* send window */ 1343 val = SET_FIELD(VAS_TX_WCRED, val, 1); 1344 write_hvwc_reg(window, VREG(TX_WCRED_ADDER), val); 1345 } else { 1346 val = SET_FIELD(VAS_LRX_WCRED, val, 1); 1347 write_hvwc_reg(window, VREG(LRX_WCRED_ADDER), val); 1348 } 1349 } 1350 1351 struct vas_window *vas_pswid_to_window(struct vas_instance *vinst, 1352 uint32_t pswid) 1353 { 1354 struct vas_window *window; 1355 int winid; 1356 1357 if (!pswid) { 1358 pr_devel("%s: called for pswid 0!\n", __func__); 1359 return ERR_PTR(-ESRCH); 1360 } 1361 1362 decode_pswid(pswid, NULL, &winid); 1363 1364 if (winid >= VAS_WINDOWS_PER_CHIP) 1365 return ERR_PTR(-ESRCH); 1366 1367 /* 1368 * If application closes the window before the hardware 1369 * returns the fault CRB, we should wait in vas_win_close() 1370 * for the pending requests. so the window must be active 1371 * and the process alive. 1372 * 1373 * If its a kernel process, we should not get any faults and 1374 * should not get here. 1375 */ 1376 window = vinst->windows[winid]; 1377 1378 if (!window) { 1379 pr_err("PSWID decode: Could not find window for winid %d pswid %d vinst 0x%p\n", 1380 winid, pswid, vinst); 1381 return NULL; 1382 } 1383 1384 /* 1385 * Do some sanity checks on the decoded window. Window should be 1386 * NX GZIP user send window. FTW windows should not incur faults 1387 * since their CRBs are ignored (not queued on FIFO or processed 1388 * by NX). 1389 */ 1390 if (!window->tx_win || !window->user_win || !window->nx_win || 1391 window->cop == VAS_COP_TYPE_FAULT || 1392 window->cop == VAS_COP_TYPE_FTW) { 1393 pr_err("PSWID decode: id %d, tx %d, user %d, nx %d, cop %d\n", 1394 winid, window->tx_win, window->user_win, 1395 window->nx_win, window->cop); 1396 WARN_ON(1); 1397 } 1398 1399 return window; 1400 } 1401 1402 static struct vas_window *vas_user_win_open(int vas_id, u64 flags, 1403 enum vas_cop_type cop_type) 1404 { 1405 struct vas_tx_win_attr txattr = {}; 1406 1407 vas_init_tx_win_attr(&txattr, cop_type); 1408 1409 txattr.lpid = mfspr(SPRN_LPID); 1410 txattr.pidr = mfspr(SPRN_PID); 1411 txattr.user_win = true; 1412 txattr.rsvd_txbuf_count = false; 1413 txattr.pswid = false; 1414 1415 pr_devel("Pid %d: Opening txwin, PIDR %ld\n", txattr.pidr, 1416 mfspr(SPRN_PID)); 1417 1418 return vas_tx_win_open(vas_id, cop_type, &txattr); 1419 } 1420 1421 static u64 vas_user_win_paste_addr(struct vas_window *win) 1422 { 1423 u64 paste_addr; 1424 1425 vas_win_paste_addr(win, &paste_addr, NULL); 1426 1427 return paste_addr; 1428 } 1429 1430 static int vas_user_win_close(struct vas_window *txwin) 1431 { 1432 1433 vas_win_close(txwin); 1434 1435 return 0; 1436 } 1437 1438 static const struct vas_user_win_ops vops = { 1439 .open_win = vas_user_win_open, 1440 .paste_addr = vas_user_win_paste_addr, 1441 .close_win = vas_user_win_close, 1442 }; 1443 1444 /* 1445 * Supporting only nx-gzip coprocessor type now, but this API code 1446 * extended to other coprocessor types later. 1447 */ 1448 int vas_register_api_powernv(struct module *mod, enum vas_cop_type cop_type, 1449 const char *name) 1450 { 1451 1452 return vas_register_coproc_api(mod, cop_type, name, &vops); 1453 } 1454 EXPORT_SYMBOL_GPL(vas_register_api_powernv); 1455 1456 void vas_unregister_api_powernv(void) 1457 { 1458 vas_unregister_coproc_api(); 1459 } 1460 EXPORT_SYMBOL_GPL(vas_unregister_api_powernv); 1461