2 * Copyright 2016-17 IBM Corp.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
10 #define pr_fmt(fmt) "vas: " fmt
12 #include <linux/types.h>
13 #include <linux/mutex.h>
14 #include <linux/slab.h>
16 #include <linux/log2.h>
17 #include <linux/rcupdate.h>
18 #include <linux/cred.h>
19 #include <asm/switch_to.h>
20 #include <asm/ppc-opcode.h>
22 #include "copy-paste.h"
24 #define CREATE_TRACE_POINTS
25 #include "vas-trace.h"
28 * Compute the paste address region for the window @window using the
29 * ->paste_base_addr and ->paste_win_id_shift we got from device tree.
31 static void compute_paste_address(struct vas_window *window, u64 *addr, int *len)
36 base = window->vinst->paste_base_addr;
37 shift = window->vinst->paste_win_id_shift;
38 winid = window->winid;
40 *addr = base + (winid << shift);
44 pr_debug("Txwin #%d: Paste addr 0x%llx\n", winid, *addr);
47 static inline void get_hvwc_mmio_bar(struct vas_window *window,
52 pbaddr = window->vinst->hvwc_bar_start;
53 *start = pbaddr + window->winid * VAS_HVWC_SIZE;
57 static inline void get_uwc_mmio_bar(struct vas_window *window,
62 pbaddr = window->vinst->uwc_bar_start;
63 *start = pbaddr + window->winid * VAS_UWC_SIZE;
68 * Map the paste bus address of the given send window into kernel address
69 * space. Unlike MMIO regions (map_mmio_region() below), paste region must
70 * be mapped cache-able and is only applicable to send windows.
72 static void *map_paste_region(struct vas_window *txwin)
79 name = kasprintf(GFP_KERNEL, "window-v%d-w%d", txwin->vinst->vas_id,
84 txwin->paste_addr_name = name;
85 compute_paste_address(txwin, &start, &len);
87 if (!request_mem_region(start, len, name)) {
88 pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n",
89 __func__, start, len);
93 map = ioremap_cache(start, len);
95 pr_devel("%s(): ioremap_cache(0x%llx, %d) failed\n", __func__,
100 pr_devel("Mapped paste addr 0x%llx to kaddr 0x%p\n", start, map);
105 return ERR_PTR(-ENOMEM);
108 static void *map_mmio_region(char *name, u64 start, int len)
112 if (!request_mem_region(start, len, name)) {
113 pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n",
114 __func__, start, len);
118 map = ioremap(start, len);
120 pr_devel("%s(): ioremap(0x%llx, %d) failed\n", __func__, start,
128 static void unmap_region(void *addr, u64 start, int len)
131 release_mem_region((phys_addr_t)start, len);
135 * Unmap the paste address region for a window.
137 static void unmap_paste_region(struct vas_window *window)
142 if (window->paste_kaddr) {
143 compute_paste_address(window, &busaddr_start, &len);
144 unmap_region(window->paste_kaddr, busaddr_start, len);
145 window->paste_kaddr = NULL;
146 kfree(window->paste_addr_name);
147 window->paste_addr_name = NULL;
152 * Unmap the MMIO regions for a window. Hold the vas_mutex so we don't
153 * unmap when the window's debugfs dir is in use. This serializes close
154 * of a window even on another VAS instance but since its not a critical
155 * path, just minimize the time we hold the mutex for now. We can add
156 * a per-instance mutex later if necessary.
158 static void unmap_winctx_mmio_bars(struct vas_window *window)
165 mutex_lock(&vas_mutex);
167 hvwc_map = window->hvwc_map;
168 window->hvwc_map = NULL;
170 uwc_map = window->uwc_map;
171 window->uwc_map = NULL;
173 mutex_unlock(&vas_mutex);
176 get_hvwc_mmio_bar(window, &busaddr_start, &len);
177 unmap_region(hvwc_map, busaddr_start, len);
181 get_uwc_mmio_bar(window, &busaddr_start, &len);
182 unmap_region(uwc_map, busaddr_start, len);
187 * Find the Hypervisor Window Context (HVWC) MMIO Base Address Region and the
188 * OS/User Window Context (UWC) MMIO Base Address Region for the given window.
189 * Map these bus addresses and save the mapped kernel addresses in @window.
191 int map_winctx_mmio_bars(struct vas_window *window)
196 get_hvwc_mmio_bar(window, &start, &len);
197 window->hvwc_map = map_mmio_region("HVWCM_Window", start, len);
199 get_uwc_mmio_bar(window, &start, &len);
200 window->uwc_map = map_mmio_region("UWCM_Window", start, len);
202 if (!window->hvwc_map || !window->uwc_map) {
203 unmap_winctx_mmio_bars(window);
211 * Reset all valid registers in the HV and OS/User Window Contexts for
212 * the window identified by @window.
214 * NOTE: We cannot really use a for loop to reset window context. Not all
215 * offsets in a window context are valid registers and the valid
216 * registers are not sequential. And, we can only write to offsets
217 * with valid registers.
219 void reset_window_regs(struct vas_window *window)
221 write_hvwc_reg(window, VREG(LPID), 0ULL);
222 write_hvwc_reg(window, VREG(PID), 0ULL);
223 write_hvwc_reg(window, VREG(XLATE_MSR), 0ULL);
224 write_hvwc_reg(window, VREG(XLATE_LPCR), 0ULL);
225 write_hvwc_reg(window, VREG(XLATE_CTL), 0ULL);
226 write_hvwc_reg(window, VREG(AMR), 0ULL);
227 write_hvwc_reg(window, VREG(SEIDR), 0ULL);
228 write_hvwc_reg(window, VREG(FAULT_TX_WIN), 0ULL);
229 write_hvwc_reg(window, VREG(OSU_INTR_SRC_RA), 0ULL);
230 write_hvwc_reg(window, VREG(HV_INTR_SRC_RA), 0ULL);
231 write_hvwc_reg(window, VREG(PSWID), 0ULL);
232 write_hvwc_reg(window, VREG(LFIFO_BAR), 0ULL);
233 write_hvwc_reg(window, VREG(LDATA_STAMP_CTL), 0ULL);
234 write_hvwc_reg(window, VREG(LDMA_CACHE_CTL), 0ULL);
235 write_hvwc_reg(window, VREG(LRFIFO_PUSH), 0ULL);
236 write_hvwc_reg(window, VREG(CURR_MSG_COUNT), 0ULL);
237 write_hvwc_reg(window, VREG(LNOTIFY_AFTER_COUNT), 0ULL);
238 write_hvwc_reg(window, VREG(LRX_WCRED), 0ULL);
239 write_hvwc_reg(window, VREG(LRX_WCRED_ADDER), 0ULL);
240 write_hvwc_reg(window, VREG(TX_WCRED), 0ULL);
241 write_hvwc_reg(window, VREG(TX_WCRED_ADDER), 0ULL);
242 write_hvwc_reg(window, VREG(LFIFO_SIZE), 0ULL);
243 write_hvwc_reg(window, VREG(WINCTL), 0ULL);
244 write_hvwc_reg(window, VREG(WIN_STATUS), 0ULL);
245 write_hvwc_reg(window, VREG(WIN_CTX_CACHING_CTL), 0ULL);
246 write_hvwc_reg(window, VREG(TX_RSVD_BUF_COUNT), 0ULL);
247 write_hvwc_reg(window, VREG(LRFIFO_WIN_PTR), 0ULL);
248 write_hvwc_reg(window, VREG(LNOTIFY_CTL), 0ULL);
249 write_hvwc_reg(window, VREG(LNOTIFY_PID), 0ULL);
250 write_hvwc_reg(window, VREG(LNOTIFY_LPID), 0ULL);
251 write_hvwc_reg(window, VREG(LNOTIFY_TID), 0ULL);
252 write_hvwc_reg(window, VREG(LNOTIFY_SCOPE), 0ULL);
253 write_hvwc_reg(window, VREG(NX_UTIL_ADDER), 0ULL);
255 /* Skip read-only registers: NX_UTIL and NX_UTIL_SE */
258 * The send and receive window credit adder registers are also
259 * accessible from HVWC and have been initialized above. We don't
260 * need to initialize from the OS/User Window Context, so skip
263 * write_uwc_reg(window, VREG(TX_WCRED_ADDER), 0ULL);
264 * write_uwc_reg(window, VREG(LRX_WCRED_ADDER), 0ULL);
269 * Initialize window context registers related to Address Translation.
270 * These registers are common to send/receive windows although they
271 * differ for user/kernel windows. As we resolve the TODOs we may
272 * want to add fields to vas_winctx and move the initialization to
273 * init_vas_winctx_regs().
275 static void init_xlate_regs(struct vas_window *window, bool user_win)
280 * MSR_TA, MSR_US are false for both kernel and user.
281 * MSR_DR and MSR_PR are false for kernel.
284 val = SET_FIELD(VAS_XLATE_MSR_HV, val, 1);
285 val = SET_FIELD(VAS_XLATE_MSR_SF, val, 1);
287 val = SET_FIELD(VAS_XLATE_MSR_DR, val, 1);
288 val = SET_FIELD(VAS_XLATE_MSR_PR, val, 1);
290 write_hvwc_reg(window, VREG(XLATE_MSR), val);
292 lpcr = mfspr(SPRN_LPCR);
295 * NOTE: From Section 5.7.8.1 Segment Lookaside Buffer of the
296 * Power ISA, v3.0B, Page size encoding is 0 = 4KB, 5 = 64KB.
298 * NOTE: From Section 1.3.1, Address Translation Context of the
299 * Nest MMU Workbook, LPCR_SC should be 0 for Power9.
301 val = SET_FIELD(VAS_XLATE_LPCR_PAGE_SIZE, val, 5);
302 val = SET_FIELD(VAS_XLATE_LPCR_ISL, val, lpcr & LPCR_ISL);
303 val = SET_FIELD(VAS_XLATE_LPCR_TC, val, lpcr & LPCR_TC);
304 val = SET_FIELD(VAS_XLATE_LPCR_SC, val, 0);
305 write_hvwc_reg(window, VREG(XLATE_LPCR), val);
308 * Section 1.3.1 (Address translation Context) of NMMU workbook.
309 * 0b00 Hashed Page Table mode
312 * 0b11 Radix on Radix
315 val = SET_FIELD(VAS_XLATE_MODE, val, radix_enabled() ? 3 : 2);
316 write_hvwc_reg(window, VREG(XLATE_CTL), val);
319 * TODO: Can we mfspr(AMR) even for user windows?
322 val = SET_FIELD(VAS_AMR, val, mfspr(SPRN_AMR));
323 write_hvwc_reg(window, VREG(AMR), val);
326 val = SET_FIELD(VAS_SEIDR, val, 0);
327 write_hvwc_reg(window, VREG(SEIDR), val);
331 * Initialize Reserved Send Buffer Count for the send window. It involves
332 * writing to the register, reading it back to confirm that the hardware
333 * has enough buffers to reserve. See section 1.3.1.2.1 of VAS workbook.
335 * Since we can only make a best-effort attempt to fulfill the request,
336 * we don't return any errors if we cannot.
338 * TODO: Reserved (aka dedicated) send buffers are not supported yet.
340 static void init_rsvd_tx_buf_count(struct vas_window *txwin,
341 struct vas_winctx *winctx)
343 write_hvwc_reg(txwin, VREG(TX_RSVD_BUF_COUNT), 0ULL);
348 * Initialize window context registers for a receive window.
349 * Except for caching control and marking window open, the registers
350 * are initialized in the order listed in Section 3.1.4 (Window Context
351 * Cache Register Details) of the VAS workbook although they don't need
354 * Design note: For NX receive windows, NX allocates the FIFO buffer in OPAL
355 * (so that it can get a large contiguous area) and passes that buffer
356 * to kernel via device tree. We now write that buffer address to the
357 * FIFO BAR. Would it make sense to do this all in OPAL? i.e have OPAL
358 * write the per-chip RX FIFO addresses to the windows during boot-up
359 * as a one-time task? That could work for NX but what about other
360 * receivers? Let the receivers tell us the rx-fifo buffers for now.
362 int init_winctx_regs(struct vas_window *window, struct vas_winctx *winctx)
367 reset_window_regs(window);
370 val = SET_FIELD(VAS_LPID, val, winctx->lpid);
371 write_hvwc_reg(window, VREG(LPID), val);
374 val = SET_FIELD(VAS_PID_ID, val, winctx->pidr);
375 write_hvwc_reg(window, VREG(PID), val);
377 init_xlate_regs(window, winctx->user_win);
380 val = SET_FIELD(VAS_FAULT_TX_WIN, val, 0);
381 write_hvwc_reg(window, VREG(FAULT_TX_WIN), val);
383 /* In PowerNV, interrupts go to HV. */
384 write_hvwc_reg(window, VREG(OSU_INTR_SRC_RA), 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);
391 val = SET_FIELD(VAS_PSWID_EA_HANDLE, val, winctx->pswid);
392 write_hvwc_reg(window, VREG(PSWID), val);
394 write_hvwc_reg(window, VREG(SPARE1), 0ULL);
395 write_hvwc_reg(window, VREG(SPARE2), 0ULL);
396 write_hvwc_reg(window, VREG(SPARE3), 0ULL);
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?
405 * See also: Design note in function header.
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);
412 val = SET_FIELD(VAS_LDATA_STAMP, val, winctx->data_stamp);
413 write_hvwc_reg(window, VREG(LDATA_STAMP_CTL), val);
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);
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);
425 val = SET_FIELD(VAS_LRX_WCRED, val, winctx->wcreds_max);
426 write_hvwc_reg(window, VREG(LRX_WCRED), val);
429 val = SET_FIELD(VAS_TX_WCRED, val, winctx->wcreds_max);
430 write_hvwc_reg(window, VREG(TX_WCRED), val);
432 write_hvwc_reg(window, VREG(LRX_WCRED_ADDER), 0ULL);
433 write_hvwc_reg(window, VREG(TX_WCRED_ADDER), 0ULL);
435 fifo_size = winctx->rx_fifo_size / 1024;
438 val = SET_FIELD(VAS_LFIFO_SIZE, val, ilog2(fifo_size));
439 write_hvwc_reg(window, VREG(LFIFO_SIZE), val);
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.
446 write_hvwc_reg(window, VREG(WIN_STATUS), 0ULL);
448 init_rsvd_tx_buf_count(window, winctx);
450 /* for a send window, point to the matching receive window */
452 val = SET_FIELD(VAS_LRX_WIN_ID, val, winctx->rx_win_id);
453 write_hvwc_reg(window, VREG(LRFIFO_WIN_PTR), val);
455 write_hvwc_reg(window, VREG(SPARE4), 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);
465 val = SET_FIELD(VAS_LNOTIFY_PID, val, winctx->lnotify_pid);
466 write_hvwc_reg(window, VREG(LNOTIFY_PID), val);
469 val = SET_FIELD(VAS_LNOTIFY_LPID, val, winctx->lnotify_lpid);
470 write_hvwc_reg(window, VREG(LNOTIFY_LPID), val);
473 val = SET_FIELD(VAS_LNOTIFY_TID, val, winctx->lnotify_tid);
474 write_hvwc_reg(window, VREG(LNOTIFY_TID), val);
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);
481 /* Skip read-only registers NX_UTIL and NX_UTIL_SE */
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);
487 /* Finally, push window context to memory and... */
489 val = SET_FIELD(VAS_PUSH_TO_MEM, val, 1);
490 write_hvwc_reg(window, VREG(WIN_CTX_CACHING_CTL), val);
492 /* ... mark the window open for business */
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);
508 static void vas_release_window_id(struct ida *ida, int winid)
510 ida_free(ida, winid);
513 static int vas_assign_window_id(struct ida *ida)
515 int winid = ida_alloc_max(ida, VAS_WINDOWS_PER_CHIP - 1, GFP_KERNEL);
517 if (winid == -ENOSPC) {
518 pr_err("Too many (%d) open windows\n", VAS_WINDOWS_PER_CHIP);
525 static void vas_window_free(struct vas_window *window)
527 int winid = window->winid;
528 struct vas_instance *vinst = window->vinst;
530 unmap_winctx_mmio_bars(window);
532 vas_window_free_dbgdir(window);
536 vas_release_window_id(&vinst->ida, winid);
539 static struct vas_window *vas_window_alloc(struct vas_instance *vinst)
542 struct vas_window *window;
544 winid = vas_assign_window_id(&vinst->ida);
546 return ERR_PTR(winid);
548 window = kzalloc(sizeof(*window), GFP_KERNEL);
552 window->vinst = vinst;
553 window->winid = winid;
555 if (map_winctx_mmio_bars(window))
558 vas_window_init_dbgdir(window);
564 vas_release_window_id(&vinst->ida, winid);
565 return ERR_PTR(-ENOMEM);
568 static void put_rx_win(struct vas_window *rxwin)
570 /* Better not be a send window! */
571 WARN_ON_ONCE(rxwin->tx_win);
573 atomic_dec(&rxwin->num_txwins);
577 * Find the user space receive window given the @pswid.
578 * - We must have a valid vasid and it must belong to this instance.
579 * (so both send and receive windows are on the same VAS instance)
580 * - The window must refer to an OPEN, FTW, RECEIVE window.
582 * NOTE: We access ->windows[] table and assume that vinst->mutex is held.
584 static struct vas_window *get_user_rxwin(struct vas_instance *vinst, u32 pswid)
587 struct vas_window *rxwin;
589 decode_pswid(pswid, &vasid, &winid);
591 if (vinst->vas_id != vasid)
592 return ERR_PTR(-EINVAL);
594 rxwin = vinst->windows[winid];
596 if (!rxwin || rxwin->tx_win || rxwin->cop != VAS_COP_TYPE_FTW)
597 return ERR_PTR(-EINVAL);
603 * Get the VAS receive window associated with NX engine identified
604 * by @cop and if applicable, @pswid.
606 * See also function header of set_vinst_win().
608 static struct vas_window *get_vinst_rxwin(struct vas_instance *vinst,
609 enum vas_cop_type cop, u32 pswid)
611 struct vas_window *rxwin;
613 mutex_lock(&vinst->mutex);
615 if (cop == VAS_COP_TYPE_FTW)
616 rxwin = get_user_rxwin(vinst, pswid);
618 rxwin = vinst->rxwin[cop] ?: ERR_PTR(-EINVAL);
621 atomic_inc(&rxwin->num_txwins);
623 mutex_unlock(&vinst->mutex);
629 * We have two tables of windows in a VAS instance. The first one,
630 * ->windows[], contains all the windows in the instance and allows
631 * looking up a window by its id. It is used to look up send windows
632 * during fault handling and receive windows when pairing user space
633 * send/receive windows.
635 * The second table, ->rxwin[], contains receive windows that are
636 * associated with NX engines. This table has VAS_COP_TYPE_MAX
637 * entries and is used to look up a receive window by its
640 * Here, we save @window in the ->windows[] table. If it is a receive
641 * window, we also save the window in the ->rxwin[] table.
643 static void set_vinst_win(struct vas_instance *vinst,
644 struct vas_window *window)
646 int id = window->winid;
648 mutex_lock(&vinst->mutex);
651 * There should only be one receive window for a coprocessor type
652 * unless its a user (FTW) window.
654 if (!window->user_win && !window->tx_win) {
655 WARN_ON_ONCE(vinst->rxwin[window->cop]);
656 vinst->rxwin[window->cop] = window;
659 WARN_ON_ONCE(vinst->windows[id] != NULL);
660 vinst->windows[id] = window;
662 mutex_unlock(&vinst->mutex);
666 * Clear this window from the table(s) of windows for this VAS instance.
667 * See also function header of set_vinst_win().
669 static void clear_vinst_win(struct vas_window *window)
671 int id = window->winid;
672 struct vas_instance *vinst = window->vinst;
674 mutex_lock(&vinst->mutex);
676 if (!window->user_win && !window->tx_win) {
677 WARN_ON_ONCE(!vinst->rxwin[window->cop]);
678 vinst->rxwin[window->cop] = NULL;
681 WARN_ON_ONCE(vinst->windows[id] != window);
682 vinst->windows[id] = NULL;
684 mutex_unlock(&vinst->mutex);
687 static void init_winctx_for_rxwin(struct vas_window *rxwin,
688 struct vas_rx_win_attr *rxattr,
689 struct vas_winctx *winctx)
692 * We first zero (memset()) all fields and only set non-zero fields.
693 * Following fields are 0/false but maybe deserve a comment:
695 * ->notify_os_intr_reg In powerNV, send intrs to HV
696 * ->notify_disable False for NX windows
697 * ->intr_disable False for Fault Windows
698 * ->xtra_write False for NX windows
699 * ->notify_early NA for NX windows
700 * ->rsvd_txbuf_count NA for Rx windows
701 * ->lpid, ->pid, ->tid NA for Rx windows
704 memset(winctx, 0, sizeof(struct vas_winctx));
706 winctx->rx_fifo = rxattr->rx_fifo;
707 winctx->rx_fifo_size = rxattr->rx_fifo_size;
708 winctx->wcreds_max = rxwin->wcreds_max;
709 winctx->pin_win = rxattr->pin_win;
711 winctx->nx_win = rxattr->nx_win;
712 winctx->fault_win = rxattr->fault_win;
713 winctx->user_win = rxattr->user_win;
714 winctx->rej_no_credit = rxattr->rej_no_credit;
715 winctx->rx_word_mode = rxattr->rx_win_ord_mode;
716 winctx->tx_word_mode = rxattr->tx_win_ord_mode;
717 winctx->rx_wcred_mode = rxattr->rx_wcred_mode;
718 winctx->tx_wcred_mode = rxattr->tx_wcred_mode;
719 winctx->notify_early = rxattr->notify_early;
721 if (winctx->nx_win) {
722 winctx->data_stamp = true;
723 winctx->intr_disable = true;
724 winctx->pin_win = true;
726 WARN_ON_ONCE(winctx->fault_win);
727 WARN_ON_ONCE(!winctx->rx_word_mode);
728 WARN_ON_ONCE(!winctx->tx_word_mode);
729 WARN_ON_ONCE(winctx->notify_after_count);
730 } else if (winctx->fault_win) {
731 winctx->notify_disable = true;
732 } else if (winctx->user_win) {
734 * Section 1.8.1 Low Latency Core-Core Wake up of
737 * - disable credit checks ([tr]x_wcred_mode = false)
738 * - disable FIFO writes
739 * - enable ASB_Notify, disable interrupt
741 winctx->fifo_disable = true;
742 winctx->intr_disable = true;
743 winctx->rx_fifo = NULL;
746 winctx->lnotify_lpid = rxattr->lnotify_lpid;
747 winctx->lnotify_pid = rxattr->lnotify_pid;
748 winctx->lnotify_tid = rxattr->lnotify_tid;
749 winctx->pswid = rxattr->pswid;
750 winctx->dma_type = VAS_DMA_TYPE_INJECT;
751 winctx->tc_mode = rxattr->tc_mode;
753 winctx->min_scope = VAS_SCOPE_LOCAL;
754 winctx->max_scope = VAS_SCOPE_VECTORED_GROUP;
757 static bool rx_win_args_valid(enum vas_cop_type cop,
758 struct vas_rx_win_attr *attr)
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,
765 if (cop >= VAS_COP_TYPE_MAX)
768 if (cop != VAS_COP_TYPE_FTW &&
769 attr->rx_fifo_size < VAS_RX_FIFO_SIZE_MIN)
772 if (attr->rx_fifo_size > VAS_RX_FIFO_SIZE_MAX)
775 if (attr->wcreds_max > VAS_RX_WCREDS_MAX)
779 /* cannot be fault or user window if it is nx */
780 if (attr->fault_win || attr->user_win)
783 * Section 3.1.4.32: NX Windows must not disable notification,
784 * and must not enable interrupts or early notification.
786 if (attr->notify_disable || !attr->intr_disable ||
789 } else if (attr->fault_win) {
790 /* cannot be both fault and user window */
795 * Section 3.1.4.32: Fault windows must disable notification
796 * but not interrupts.
798 if (!attr->notify_disable || attr->intr_disable)
801 } else if (attr->user_win) {
803 * User receive windows are only for fast-thread-wakeup
804 * (FTW). They don't need a FIFO and must disable interrupts
806 if (attr->rx_fifo || attr->rx_fifo_size || !attr->intr_disable)
809 /* Rx window must be one of NX or Fault or User window. */
816 void vas_init_rx_win_attr(struct vas_rx_win_attr *rxattr, enum vas_cop_type cop)
818 memset(rxattr, 0, sizeof(*rxattr));
820 if (cop == VAS_COP_TYPE_842 || cop == VAS_COP_TYPE_842_HIPRI) {
821 rxattr->pin_win = true;
822 rxattr->nx_win = true;
823 rxattr->fault_win = false;
824 rxattr->intr_disable = true;
825 rxattr->rx_wcred_mode = true;
826 rxattr->tx_wcred_mode = true;
827 rxattr->rx_win_ord_mode = true;
828 rxattr->tx_win_ord_mode = true;
829 } else if (cop == VAS_COP_TYPE_FAULT) {
830 rxattr->pin_win = true;
831 rxattr->fault_win = true;
832 rxattr->notify_disable = true;
833 rxattr->rx_wcred_mode = true;
834 rxattr->tx_wcred_mode = true;
835 rxattr->rx_win_ord_mode = true;
836 rxattr->tx_win_ord_mode = true;
837 } else if (cop == VAS_COP_TYPE_FTW) {
838 rxattr->user_win = true;
839 rxattr->intr_disable = true;
842 * As noted in the VAS Workbook we disable credit checks.
843 * If we enable credit checks in the future, we must also
844 * implement a mechanism to return the user credits or new
845 * paste operations will fail.
849 EXPORT_SYMBOL_GPL(vas_init_rx_win_attr);
851 struct vas_window *vas_rx_win_open(int vasid, enum vas_cop_type cop,
852 struct vas_rx_win_attr *rxattr)
854 struct vas_window *rxwin;
855 struct vas_winctx winctx;
856 struct vas_instance *vinst;
858 trace_vas_rx_win_open(current, vasid, cop, rxattr);
860 if (!rx_win_args_valid(cop, rxattr))
861 return ERR_PTR(-EINVAL);
863 vinst = find_vas_instance(vasid);
865 pr_devel("vasid %d not found!\n", vasid);
866 return ERR_PTR(-EINVAL);
868 pr_devel("Found instance %d\n", vasid);
870 rxwin = vas_window_alloc(vinst);
872 pr_devel("Unable to allocate memory for Rx window\n");
876 rxwin->tx_win = false;
877 rxwin->nx_win = rxattr->nx_win;
878 rxwin->user_win = rxattr->user_win;
880 rxwin->wcreds_max = rxattr->wcreds_max ?: VAS_WCREDS_DEFAULT;
881 if (rxattr->user_win)
882 rxwin->pid = task_pid_vnr(current);
884 init_winctx_for_rxwin(rxwin, rxattr, &winctx);
885 init_winctx_regs(rxwin, &winctx);
887 set_vinst_win(vinst, rxwin);
891 EXPORT_SYMBOL_GPL(vas_rx_win_open);
893 void vas_init_tx_win_attr(struct vas_tx_win_attr *txattr, enum vas_cop_type cop)
895 memset(txattr, 0, sizeof(*txattr));
897 if (cop == VAS_COP_TYPE_842 || cop == VAS_COP_TYPE_842_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;
907 EXPORT_SYMBOL_GPL(vas_init_tx_win_attr);
909 static void init_winctx_for_txwin(struct vas_window *txwin,
910 struct vas_tx_win_attr *txattr,
911 struct vas_winctx *winctx)
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:
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
928 memset(winctx, 0, sizeof(struct vas_winctx));
930 winctx->wcreds_max = txwin->wcreds_max;
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;
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;
944 winctx->intr_disable = true;
946 winctx->data_stamp = true;
948 winctx->lpid = txattr->lpid;
949 winctx->pidr = txattr->pidr;
950 winctx->rx_win_id = txwin->rxwin->winid;
952 winctx->dma_type = VAS_DMA_TYPE_INJECT;
953 winctx->tc_mode = txattr->tc_mode;
954 winctx->min_scope = VAS_SCOPE_LOCAL;
955 winctx->max_scope = VAS_SCOPE_VECTORED_GROUP;
960 static bool tx_win_args_valid(enum vas_cop_type cop,
961 struct vas_tx_win_attr *attr)
963 if (attr->tc_mode != VAS_THRESH_DISABLED)
966 if (cop > VAS_COP_TYPE_MAX)
969 if (attr->wcreds_max > VAS_TX_WCREDS_MAX)
972 if (attr->user_win &&
973 (cop != VAS_COP_TYPE_FTW || attr->rsvd_txbuf_count))
979 struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
980 struct vas_tx_win_attr *attr)
983 struct vas_window *txwin;
984 struct vas_window *rxwin;
985 struct vas_winctx winctx;
986 struct vas_instance *vinst;
988 trace_vas_tx_win_open(current, vasid, cop, attr);
990 if (!tx_win_args_valid(cop, attr))
991 return ERR_PTR(-EINVAL);
994 * If caller did not specify a vasid but specified the PSWID of a
995 * receive window (applicable only to FTW windows), use the vasid
996 * from that receive window.
998 if (vasid == -1 && attr->pswid)
999 decode_pswid(attr->pswid, &vasid, NULL);
1001 vinst = find_vas_instance(vasid);
1003 pr_devel("vasid %d not found!\n", vasid);
1004 return ERR_PTR(-EINVAL);
1007 rxwin = get_vinst_rxwin(vinst, cop, attr->pswid);
1008 if (IS_ERR(rxwin)) {
1009 pr_devel("No RxWin for vasid %d, cop %d\n", vasid, cop);
1013 txwin = vas_window_alloc(vinst);
1014 if (IS_ERR(txwin)) {
1015 rc = PTR_ERR(txwin);
1021 txwin->rxwin = rxwin;
1022 txwin->nx_win = txwin->rxwin->nx_win;
1023 txwin->pid = attr->pid;
1024 txwin->user_win = attr->user_win;
1025 txwin->wcreds_max = attr->wcreds_max ?: VAS_WCREDS_DEFAULT;
1027 init_winctx_for_txwin(txwin, attr, &winctx);
1029 init_winctx_regs(txwin, &winctx);
1032 * If its a kernel send window, map the window address into the
1033 * kernel's address space. For user windows, user must issue an
1034 * mmap() to map the window into their address space.
1036 * NOTE: If kernel ever resubmits a user CRB after handling a page
1037 * fault, we will need to map this into kernel as well.
1039 if (!txwin->user_win) {
1040 txwin->paste_kaddr = map_paste_region(txwin);
1041 if (IS_ERR(txwin->paste_kaddr)) {
1042 rc = PTR_ERR(txwin->paste_kaddr);
1047 * A user mapping must ensure that context switch issues
1048 * CP_ABORT for this thread.
1050 rc = set_thread_uses_vas();
1055 set_vinst_win(vinst, txwin);
1060 vas_window_free(txwin);
1067 EXPORT_SYMBOL_GPL(vas_tx_win_open);
1069 int vas_copy_crb(void *crb, int offset)
1071 return vas_copy(crb, offset);
1073 EXPORT_SYMBOL_GPL(vas_copy_crb);
1075 #define RMA_LSMP_REPORT_ENABLE PPC_BIT(53)
1076 int vas_paste_crb(struct vas_window *txwin, int offset, bool re)
1082 trace_vas_paste_crb(current, txwin);
1085 * Only NX windows are supported for now and hardware assumes
1086 * report-enable flag is set for NX windows. Ensure software
1089 WARN_ON_ONCE(txwin->nx_win && !re);
1091 addr = txwin->paste_kaddr;
1094 * Set the REPORT_ENABLE bit (equivalent to writing
1095 * to 1K offset of the paste address)
1097 val = SET_FIELD(RMA_LSMP_REPORT_ENABLE, 0ULL, 1);
1102 * Map the raw CR value from vas_paste() to an error code (there
1103 * is just pass or fail for now though).
1105 rc = vas_paste(addr, offset);
1111 pr_debug("Txwin #%d: Msg count %llu\n", txwin->winid,
1112 read_hvwc_reg(txwin, VREG(LRFIFO_PUSH)));
1116 EXPORT_SYMBOL_GPL(vas_paste_crb);
1119 * If credit checking is enabled for this window, poll for the return
1120 * of window credits (i.e for NX engines to process any outstanding CRBs).
1121 * Since NX-842 waits for the CRBs to be processed before closing the
1122 * window, we should not have to wait for too long.
1124 * TODO: We retry in 10ms intervals now. We could/should probably peek at
1125 * the VAS_LRFIFO_PUSH_OFFSET register to get an estimate of pending
1126 * CRBs on the FIFO and compute the delay dynamically on each retry.
1127 * But that is not really needed until we support NX-GZIP access from
1128 * user space. (NX-842 driver waits for CSB and Fast thread-wakeup
1129 * doesn't use credit checking).
1131 static void poll_window_credits(struct vas_window *window)
1136 val = read_hvwc_reg(window, VREG(WINCTL));
1138 mode = GET_FIELD(VAS_WINCTL_TX_WCRED_MODE, val);
1140 mode = GET_FIELD(VAS_WINCTL_RX_WCRED_MODE, val);
1145 if (window->tx_win) {
1146 val = read_hvwc_reg(window, VREG(TX_WCRED));
1147 creds = GET_FIELD(VAS_TX_WCRED, val);
1149 val = read_hvwc_reg(window, VREG(LRX_WCRED));
1150 creds = GET_FIELD(VAS_LRX_WCRED, val);
1153 if (creds < window->wcreds_max) {
1155 set_current_state(TASK_UNINTERRUPTIBLE);
1156 schedule_timeout(msecs_to_jiffies(10));
1162 * Wait for the window to go to "not-busy" state. It should only take a
1163 * short time to queue a CRB, so window should not be busy for too long.
1164 * Trying 5ms intervals.
1166 static void poll_window_busy_state(struct vas_window *window)
1172 val = read_hvwc_reg(window, VREG(WIN_STATUS));
1173 busy = GET_FIELD(VAS_WIN_BUSY, val);
1176 set_current_state(TASK_UNINTERRUPTIBLE);
1177 schedule_timeout(msecs_to_jiffies(5));
1183 * Have the hardware cast a window out of cache and wait for it to
1186 * NOTE: It can take a relatively long time to cast the window context
1187 * out of the cache. It is not strictly necessary to cast out if:
1189 * - we clear the "Pin Window" bit (so hardware is free to evict)
1191 * - we re-initialize the window context when it is reassigned.
1193 * We do the former in vas_win_close() and latter in vas_win_open().
1194 * So, ignoring the cast-out for now. We can add it as needed. If
1195 * casting out becomes necessary we should consider offloading the
1196 * job to a worker thread, so the window close can proceed quickly.
1198 static void poll_window_castout(struct vas_window *window)
1204 * Unpin and close a window so no new requests are accepted and the
1205 * hardware can evict this window from cache if necessary.
1207 static void unpin_close_window(struct vas_window *window)
1211 val = read_hvwc_reg(window, VREG(WINCTL));
1212 val = SET_FIELD(VAS_WINCTL_PIN, val, 0);
1213 val = SET_FIELD(VAS_WINCTL_OPEN, val, 0);
1214 write_hvwc_reg(window, VREG(WINCTL), val);
1220 * See Section 1.12.1 of VAS workbook v1.05 for details on closing window:
1221 * - Disable new paste operations (unmap paste address)
1222 * - Poll for the "Window Busy" bit to be cleared
1223 * - Clear the Open/Enable bit for the Window.
1224 * - Poll for return of window Credits (implies FIFO empty for Rx win?)
1225 * - Unpin and cast window context out of cache
1227 * Besides the hardware, kernel has some bookkeeping of course.
1229 int vas_win_close(struct vas_window *window)
1234 if (!window->tx_win && atomic_read(&window->num_txwins) != 0) {
1235 pr_devel("Attempting to close an active Rx window!\n");
1240 unmap_paste_region(window);
1242 clear_vinst_win(window);
1244 poll_window_busy_state(window);
1246 unpin_close_window(window);
1248 poll_window_credits(window);
1250 poll_window_castout(window);
1252 /* if send window, drop reference to matching receive window */
1254 put_rx_win(window->rxwin);
1256 vas_window_free(window);
1260 EXPORT_SYMBOL_GPL(vas_win_close);