2 * SN Platform GRU Driver
4 * DRIVER TABLE MANAGER + GRU CONTEXT LOAD/UNLOAD
6 * Copyright (c) 2008 Silicon Graphics, Inc. All Rights Reserved.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #include <linux/kernel.h>
24 #include <linux/slab.h>
26 #include <linux/spinlock.h>
27 #include <linux/sched.h>
28 #include <linux/device.h>
29 #include <linux/list.h>
30 #include <linux/err.h>
31 #include <linux/prefetch.h>
32 #include <asm/uv/uv_hub.h>
34 #include "grutables.h"
35 #include "gruhandles.h"
37 unsigned long gru_options __read_mostly;
39 static struct device_driver gru_driver = {
43 static struct device gru_device = {
45 .driver = &gru_driver,
48 struct device *grudev = &gru_device;
51 * Select a gru fault map to be used by the current cpu. Note that
52 * multiple cpus may be using the same map.
53 * ZZZ should be inline but did not work on emulator
55 int gru_cpu_fault_map_id(void)
58 return uv_blade_processor_id() % GRU_NUM_TFM;
60 int cpu = smp_processor_id();
63 core = uv_cpu_core_number(cpu);
64 id = core + UV_MAX_INT_CORES * uv_cpu_socket_number(cpu);
69 /*--------- ASID Management -------------------------------------------
71 * Initially, assign asids sequentially from MIN_ASID .. MAX_ASID.
72 * Once MAX is reached, flush the TLB & start over. However,
73 * some asids may still be in use. There won't be many (percentage wise) still
74 * in use. Search active contexts & determine the value of the first
75 * asid in use ("x"s below). Set "limit" to this value.
76 * This defines a block of assignable asids.
78 * When "limit" is reached, search forward from limit+1 and determine the
79 * next block of assignable asids.
81 * Repeat until MAX_ASID is reached, then start over again.
83 * Each time MAX_ASID is reached, increment the asid generation. Since
84 * the search for in-use asids only checks contexts with GRUs currently
85 * assigned, asids in some contexts will be missed. Prior to loading
86 * a context, the asid generation of the GTS asid is rechecked. If it
87 * doesn't match the current generation, a new asid will be assigned.
89 * 0---------------x------------x---------------------x----|
90 * ^-next ^-limit ^-MAX_ASID
92 * All asid manipulation & context loading/unloading is protected by the
96 /* Hit the asid limit. Start over */
97 static int gru_wrap_asid(struct gru_state *gru)
99 gru_dbg(grudev, "gid %d\n", gru->gs_gid);
105 /* Find the next chunk of unused asids */
106 static int gru_reset_asid_limit(struct gru_state *gru, int asid)
108 int i, gid, inuse_asid, limit;
110 gru_dbg(grudev, "gid %d, asid 0x%x\n", gru->gs_gid, asid);
114 asid = gru_wrap_asid(gru);
115 gru_flush_all_tlb(gru);
118 for (i = 0; i < GRU_NUM_CCH; i++) {
119 if (!gru->gs_gts[i] || is_kernel_context(gru->gs_gts[i]))
121 inuse_asid = gru->gs_gts[i]->ts_gms->ms_asids[gid].mt_asid;
122 gru_dbg(grudev, "gid %d, gts %p, gms %p, inuse 0x%x, cxt %d\n",
123 gru->gs_gid, gru->gs_gts[i], gru->gs_gts[i]->ts_gms,
125 if (inuse_asid == asid) {
129 * empty range: reset the range limit and
133 if (asid >= MAX_ASID)
134 asid = gru_wrap_asid(gru);
139 if ((inuse_asid > asid) && (inuse_asid < limit))
142 gru->gs_asid_limit = limit;
144 gru_dbg(grudev, "gid %d, new asid 0x%x, new_limit 0x%x\n", gru->gs_gid,
149 /* Assign a new ASID to a thread context. */
150 static int gru_assign_asid(struct gru_state *gru)
154 gru->gs_asid += ASID_INC;
156 if (asid >= gru->gs_asid_limit)
157 asid = gru_reset_asid_limit(gru, asid);
159 gru_dbg(grudev, "gid %d, asid 0x%x\n", gru->gs_gid, asid);
164 * Clear n bits in a word. Return a word indicating the bits that were cleared.
165 * Optionally, build an array of chars that contain the bit numbers allocated.
167 static unsigned long reserve_resources(unsigned long *p, int n, int mmax,
170 unsigned long bits = 0;
174 i = find_first_bit(p, mmax);
185 unsigned long gru_reserve_cb_resources(struct gru_state *gru, int cbr_au_count,
188 return reserve_resources(&gru->gs_cbr_map, cbr_au_count, GRU_CBR_AU,
192 unsigned long gru_reserve_ds_resources(struct gru_state *gru, int dsr_au_count,
195 return reserve_resources(&gru->gs_dsr_map, dsr_au_count, GRU_DSR_AU,
199 static void reserve_gru_resources(struct gru_state *gru,
200 struct gru_thread_state *gts)
202 gru->gs_active_contexts++;
204 gru_reserve_cb_resources(gru, gts->ts_cbr_au_count,
207 gru_reserve_ds_resources(gru, gts->ts_dsr_au_count, NULL);
210 static void free_gru_resources(struct gru_state *gru,
211 struct gru_thread_state *gts)
213 gru->gs_active_contexts--;
214 gru->gs_cbr_map |= gts->ts_cbr_map;
215 gru->gs_dsr_map |= gts->ts_dsr_map;
219 * Check if a GRU has sufficient free resources to satisfy an allocation
220 * request. Note: GRU locks may or may not be held when this is called. If
221 * not held, recheck after acquiring the appropriate locks.
223 * Returns 1 if sufficient resources, 0 if not
225 static int check_gru_resources(struct gru_state *gru, int cbr_au_count,
226 int dsr_au_count, int max_active_contexts)
228 return hweight64(gru->gs_cbr_map) >= cbr_au_count
229 && hweight64(gru->gs_dsr_map) >= dsr_au_count
230 && gru->gs_active_contexts < max_active_contexts;
234 * TLB manangment requires tracking all GRU chiplets that have loaded a GSEG
237 static int gru_load_mm_tracker(struct gru_state *gru,
238 struct gru_thread_state *gts)
240 struct gru_mm_struct *gms = gts->ts_gms;
241 struct gru_mm_tracker *asids = &gms->ms_asids[gru->gs_gid];
242 unsigned short ctxbitmap = (1 << gts->ts_ctxnum);
245 spin_lock(&gms->ms_asid_lock);
246 asid = asids->mt_asid;
248 spin_lock(&gru->gs_asid_lock);
249 if (asid == 0 || (asids->mt_ctxbitmap == 0 && asids->mt_asid_gen !=
251 asid = gru_assign_asid(gru);
252 asids->mt_asid = asid;
253 asids->mt_asid_gen = gru->gs_asid_gen;
258 spin_unlock(&gru->gs_asid_lock);
260 BUG_ON(asids->mt_ctxbitmap & ctxbitmap);
261 asids->mt_ctxbitmap |= ctxbitmap;
262 if (!test_bit(gru->gs_gid, gms->ms_asidmap))
263 __set_bit(gru->gs_gid, gms->ms_asidmap);
264 spin_unlock(&gms->ms_asid_lock);
267 "gid %d, gts %p, gms %p, ctxnum %d, asid 0x%x, asidmap 0x%lx\n",
268 gru->gs_gid, gts, gms, gts->ts_ctxnum, asid,
273 static void gru_unload_mm_tracker(struct gru_state *gru,
274 struct gru_thread_state *gts)
276 struct gru_mm_struct *gms = gts->ts_gms;
277 struct gru_mm_tracker *asids;
278 unsigned short ctxbitmap;
280 asids = &gms->ms_asids[gru->gs_gid];
281 ctxbitmap = (1 << gts->ts_ctxnum);
282 spin_lock(&gms->ms_asid_lock);
283 spin_lock(&gru->gs_asid_lock);
284 BUG_ON((asids->mt_ctxbitmap & ctxbitmap) != ctxbitmap);
285 asids->mt_ctxbitmap ^= ctxbitmap;
286 gru_dbg(grudev, "gid %d, gts %p, gms %p, ctxnum 0x%d, asidmap 0x%lx\n",
287 gru->gs_gid, gts, gms, gts->ts_ctxnum, gms->ms_asidmap[0]);
288 spin_unlock(&gru->gs_asid_lock);
289 spin_unlock(&gms->ms_asid_lock);
293 * Decrement the reference count on a GTS structure. Free the structure
294 * if the reference count goes to zero.
296 void gts_drop(struct gru_thread_state *gts)
298 if (gts && atomic_dec_return(>s->ts_refcnt) == 0) {
300 gru_drop_mmu_notifier(gts->ts_gms);
307 * Locate the GTS structure for the current thread.
309 static struct gru_thread_state *gru_find_current_gts_nolock(struct gru_vma_data
312 struct gru_thread_state *gts;
314 list_for_each_entry(gts, &vdata->vd_head, ts_next)
315 if (gts->ts_tsid == tsid)
321 * Allocate a thread state structure.
323 struct gru_thread_state *gru_alloc_gts(struct vm_area_struct *vma,
324 int cbr_au_count, int dsr_au_count,
325 unsigned char tlb_preload_count, int options, int tsid)
327 struct gru_thread_state *gts;
328 struct gru_mm_struct *gms;
331 bytes = DSR_BYTES(dsr_au_count) + CBR_BYTES(cbr_au_count);
332 bytes += sizeof(struct gru_thread_state);
333 gts = kmalloc(bytes, GFP_KERNEL);
335 return ERR_PTR(-ENOMEM);
338 memset(gts, 0, sizeof(struct gru_thread_state)); /* zero out header */
339 atomic_set(>s->ts_refcnt, 1);
340 mutex_init(>s->ts_ctxlock);
341 gts->ts_cbr_au_count = cbr_au_count;
342 gts->ts_dsr_au_count = dsr_au_count;
343 gts->ts_tlb_preload_count = tlb_preload_count;
344 gts->ts_user_options = options;
345 gts->ts_user_blade_id = -1;
346 gts->ts_user_chiplet_id = -1;
348 gts->ts_ctxnum = NULLCTX;
349 gts->ts_tlb_int_select = -1;
350 gts->ts_cch_req_slice = -1;
351 gts->ts_sizeavail = GRU_SIZEAVAIL(PAGE_SHIFT);
353 gts->ts_mm = current->mm;
355 gms = gru_register_mmu_notifier();
361 gru_dbg(grudev, "alloc gts %p\n", gts);
366 return ERR_CAST(gms);
370 * Allocate a vma private data structure.
372 struct gru_vma_data *gru_alloc_vma_data(struct vm_area_struct *vma, int tsid)
374 struct gru_vma_data *vdata = NULL;
376 vdata = kmalloc(sizeof(*vdata), GFP_KERNEL);
381 INIT_LIST_HEAD(&vdata->vd_head);
382 spin_lock_init(&vdata->vd_lock);
383 gru_dbg(grudev, "alloc vdata %p\n", vdata);
388 * Find the thread state structure for the current thread.
390 struct gru_thread_state *gru_find_thread_state(struct vm_area_struct *vma,
393 struct gru_vma_data *vdata = vma->vm_private_data;
394 struct gru_thread_state *gts;
396 spin_lock(&vdata->vd_lock);
397 gts = gru_find_current_gts_nolock(vdata, tsid);
398 spin_unlock(&vdata->vd_lock);
399 gru_dbg(grudev, "vma %p, gts %p\n", vma, gts);
404 * Allocate a new thread state for a GSEG. Note that races may allow
405 * another thread to race to create a gts.
407 struct gru_thread_state *gru_alloc_thread_state(struct vm_area_struct *vma,
410 struct gru_vma_data *vdata = vma->vm_private_data;
411 struct gru_thread_state *gts, *ngts;
413 gts = gru_alloc_gts(vma, vdata->vd_cbr_au_count,
414 vdata->vd_dsr_au_count,
415 vdata->vd_tlb_preload_count,
416 vdata->vd_user_options, tsid);
420 spin_lock(&vdata->vd_lock);
421 ngts = gru_find_current_gts_nolock(vdata, tsid);
425 STAT(gts_double_allocate);
427 list_add(>s->ts_next, &vdata->vd_head);
429 spin_unlock(&vdata->vd_lock);
430 gru_dbg(grudev, "vma %p, gts %p\n", vma, gts);
435 * Free the GRU context assigned to the thread state.
437 static void gru_free_gru_context(struct gru_thread_state *gts)
439 struct gru_state *gru;
442 gru_dbg(grudev, "gts %p, gid %d\n", gts, gru->gs_gid);
444 spin_lock(&gru->gs_lock);
445 gru->gs_gts[gts->ts_ctxnum] = NULL;
446 free_gru_resources(gru, gts);
447 BUG_ON(test_bit(gts->ts_ctxnum, &gru->gs_context_map) == 0);
448 __clear_bit(gts->ts_ctxnum, &gru->gs_context_map);
449 gts->ts_ctxnum = NULLCTX;
452 spin_unlock(&gru->gs_lock);
459 * Prefetching cachelines help hardware performance.
460 * (Strictly a performance enhancement. Not functionally required).
462 static void prefetch_data(void *p, int num, int stride)
470 static inline long gru_copy_handle(void *d, void *s)
472 memcpy(d, s, GRU_HANDLE_BYTES);
473 return GRU_HANDLE_BYTES;
476 static void gru_prefetch_context(void *gseg, void *cb, void *cbe,
477 unsigned long cbrmap, unsigned long length)
481 prefetch_data(gseg + GRU_DS_BASE, length / GRU_CACHE_LINE_BYTES,
482 GRU_CACHE_LINE_BYTES);
484 for_each_cbr_in_allocation_map(i, &cbrmap, scr) {
485 prefetch_data(cb, 1, GRU_CACHE_LINE_BYTES);
486 prefetch_data(cbe + i * GRU_HANDLE_STRIDE, 1,
487 GRU_CACHE_LINE_BYTES);
488 cb += GRU_HANDLE_STRIDE;
492 static void gru_load_context_data(void *save, void *grubase, int ctxnum,
493 unsigned long cbrmap, unsigned long dsrmap,
496 void *gseg, *cb, *cbe;
497 unsigned long length;
500 gseg = grubase + ctxnum * GRU_GSEG_STRIDE;
501 cb = gseg + GRU_CB_BASE;
502 cbe = grubase + GRU_CBE_BASE;
503 length = hweight64(dsrmap) * GRU_DSR_AU_BYTES;
504 gru_prefetch_context(gseg, cb, cbe, cbrmap, length);
506 for_each_cbr_in_allocation_map(i, &cbrmap, scr) {
508 save += gru_copy_handle(cb, save);
509 save += gru_copy_handle(cbe + i * GRU_HANDLE_STRIDE,
512 memset(cb, 0, GRU_CACHE_LINE_BYTES);
513 memset(cbe + i * GRU_HANDLE_STRIDE, 0,
514 GRU_CACHE_LINE_BYTES);
516 /* Flush CBE to hide race in context restart */
518 gru_flush_cache(cbe + i * GRU_HANDLE_STRIDE);
519 cb += GRU_HANDLE_STRIDE;
523 memcpy(gseg + GRU_DS_BASE, save, length);
525 memset(gseg + GRU_DS_BASE, 0, length);
528 static void gru_unload_context_data(void *save, void *grubase, int ctxnum,
529 unsigned long cbrmap, unsigned long dsrmap)
531 void *gseg, *cb, *cbe;
532 unsigned long length;
535 gseg = grubase + ctxnum * GRU_GSEG_STRIDE;
536 cb = gseg + GRU_CB_BASE;
537 cbe = grubase + GRU_CBE_BASE;
538 length = hweight64(dsrmap) * GRU_DSR_AU_BYTES;
540 /* CBEs may not be coherent. Flush them from cache */
541 for_each_cbr_in_allocation_map(i, &cbrmap, scr)
542 gru_flush_cache(cbe + i * GRU_HANDLE_STRIDE);
543 mb(); /* Let the CL flush complete */
545 gru_prefetch_context(gseg, cb, cbe, cbrmap, length);
547 for_each_cbr_in_allocation_map(i, &cbrmap, scr) {
548 save += gru_copy_handle(save, cb);
549 save += gru_copy_handle(save, cbe + i * GRU_HANDLE_STRIDE);
550 cb += GRU_HANDLE_STRIDE;
552 memcpy(save, gseg + GRU_DS_BASE, length);
555 void gru_unload_context(struct gru_thread_state *gts, int savestate)
557 struct gru_state *gru = gts->ts_gru;
558 struct gru_context_configuration_handle *cch;
559 int ctxnum = gts->ts_ctxnum;
561 if (!is_kernel_context(gts))
562 zap_vma_ptes(gts->ts_vma, UGRUADDR(gts), GRU_GSEG_PAGESIZE);
563 cch = get_cch(gru->gs_gru_base_vaddr, ctxnum);
565 gru_dbg(grudev, "gts %p, cbrmap 0x%lx, dsrmap 0x%lx\n",
566 gts, gts->ts_cbr_map, gts->ts_dsr_map);
567 lock_cch_handle(cch);
568 if (cch_interrupt_sync(cch))
571 if (!is_kernel_context(gts))
572 gru_unload_mm_tracker(gru, gts);
574 gru_unload_context_data(gts->ts_gdata, gru->gs_gru_base_vaddr,
575 ctxnum, gts->ts_cbr_map,
577 gts->ts_data_valid = 1;
580 if (cch_deallocate(cch))
582 unlock_cch_handle(cch);
584 gru_free_gru_context(gts);
588 * Load a GRU context by copying it from the thread data structure in memory
591 void gru_load_context(struct gru_thread_state *gts)
593 struct gru_state *gru = gts->ts_gru;
594 struct gru_context_configuration_handle *cch;
595 int i, err, asid, ctxnum = gts->ts_ctxnum;
597 cch = get_cch(gru->gs_gru_base_vaddr, ctxnum);
598 lock_cch_handle(cch);
599 cch->tfm_fault_bit_enable =
600 (gts->ts_user_options == GRU_OPT_MISS_FMM_POLL
601 || gts->ts_user_options == GRU_OPT_MISS_FMM_INTR);
602 cch->tlb_int_enable = (gts->ts_user_options == GRU_OPT_MISS_FMM_INTR);
603 if (cch->tlb_int_enable) {
604 gts->ts_tlb_int_select = gru_cpu_fault_map_id();
605 cch->tlb_int_select = gts->ts_tlb_int_select;
607 if (gts->ts_cch_req_slice >= 0) {
608 cch->req_slice_set_enable = 1;
609 cch->req_slice = gts->ts_cch_req_slice;
611 cch->req_slice_set_enable =0;
613 cch->tfm_done_bit_enable = 0;
614 cch->dsr_allocation_map = gts->ts_dsr_map;
615 cch->cbr_allocation_map = gts->ts_cbr_map;
617 if (is_kernel_context(gts)) {
618 cch->unmap_enable = 1;
619 cch->tfm_done_bit_enable = 1;
620 cch->cb_int_enable = 1;
621 cch->tlb_int_select = 0; /* For now, ints go to cpu 0 */
623 cch->unmap_enable = 0;
624 cch->tfm_done_bit_enable = 0;
625 cch->cb_int_enable = 0;
626 asid = gru_load_mm_tracker(gru, gts);
627 for (i = 0; i < 8; i++) {
628 cch->asid[i] = asid + i;
629 cch->sizeavail[i] = gts->ts_sizeavail;
633 err = cch_allocate(cch);
636 "err %d: cch %p, gts %p, cbr 0x%lx, dsr 0x%lx\n",
637 err, cch, gts, gts->ts_cbr_map, gts->ts_dsr_map);
641 gru_load_context_data(gts->ts_gdata, gru->gs_gru_base_vaddr, ctxnum,
642 gts->ts_cbr_map, gts->ts_dsr_map, gts->ts_data_valid);
646 unlock_cch_handle(cch);
648 gru_dbg(grudev, "gid %d, gts %p, cbrmap 0x%lx, dsrmap 0x%lx, tie %d, tis %d\n",
649 gts->ts_gru->gs_gid, gts, gts->ts_cbr_map, gts->ts_dsr_map,
650 (gts->ts_user_options == GRU_OPT_MISS_FMM_INTR), gts->ts_tlb_int_select);
654 * Update fields in an active CCH:
655 * - retarget interrupts on local blade
656 * - update sizeavail mask
658 int gru_update_cch(struct gru_thread_state *gts)
660 struct gru_context_configuration_handle *cch;
661 struct gru_state *gru = gts->ts_gru;
662 int i, ctxnum = gts->ts_ctxnum, ret = 0;
664 cch = get_cch(gru->gs_gru_base_vaddr, ctxnum);
666 lock_cch_handle(cch);
667 if (cch->state == CCHSTATE_ACTIVE) {
668 if (gru->gs_gts[gts->ts_ctxnum] != gts)
670 if (cch_interrupt(cch))
672 for (i = 0; i < 8; i++)
673 cch->sizeavail[i] = gts->ts_sizeavail;
674 gts->ts_tlb_int_select = gru_cpu_fault_map_id();
675 cch->tlb_int_select = gru_cpu_fault_map_id();
676 cch->tfm_fault_bit_enable =
677 (gts->ts_user_options == GRU_OPT_MISS_FMM_POLL
678 || gts->ts_user_options == GRU_OPT_MISS_FMM_INTR);
684 unlock_cch_handle(cch);
689 * Update CCH tlb interrupt select. Required when all the following is true:
690 * - task's GRU context is loaded into a GRU
691 * - task is using interrupt notification for TLB faults
692 * - task has migrated to a different cpu on the same blade where
693 * it was previously running.
695 static int gru_retarget_intr(struct gru_thread_state *gts)
697 if (gts->ts_tlb_int_select < 0
698 || gts->ts_tlb_int_select == gru_cpu_fault_map_id())
701 gru_dbg(grudev, "retarget from %d to %d\n", gts->ts_tlb_int_select,
702 gru_cpu_fault_map_id());
703 return gru_update_cch(gts);
707 * Check if a GRU context is allowed to use a specific chiplet. By default
708 * a context is assigned to any blade-local chiplet. However, users can
710 * Returns 1 if assignment allowed, 0 otherwise
712 static int gru_check_chiplet_assignment(struct gru_state *gru,
713 struct gru_thread_state *gts)
718 blade_id = gts->ts_user_blade_id;
720 blade_id = uv_numa_blade_id();
722 chiplet_id = gts->ts_user_chiplet_id;
723 return gru->gs_blade_id == blade_id &&
724 (chiplet_id < 0 || chiplet_id == gru->gs_chiplet_id);
728 * Unload the gru context if it is not assigned to the correct blade or
729 * chiplet. Misassignment can occur if the process migrates to a different
730 * blade or if the user changes the selected blade/chiplet.
732 void gru_check_context_placement(struct gru_thread_state *gts)
734 struct gru_state *gru;
737 * If the current task is the context owner, verify that the
738 * context is correctly placed. This test is skipped for non-owner
739 * references. Pthread apps use non-owner references to the CBRs.
742 if (!gru || gts->ts_tgid_owner != current->tgid)
745 if (!gru_check_chiplet_assignment(gru, gts)) {
746 STAT(check_context_unload);
747 gru_unload_context(gts, 1);
748 } else if (gru_retarget_intr(gts)) {
749 STAT(check_context_retarget_intr);
755 * Insufficient GRU resources available on the local blade. Steal a context from
756 * a process. This is a hack until a _real_ resource scheduler is written....
758 #define next_ctxnum(n) ((n) < GRU_NUM_CCH - 2 ? (n) + 1 : 0)
759 #define next_gru(b, g) (((g) < &(b)->bs_grus[GRU_CHIPLETS_PER_BLADE - 1]) ? \
760 ((g)+1) : &(b)->bs_grus[0])
762 static int is_gts_stealable(struct gru_thread_state *gts,
763 struct gru_blade_state *bs)
765 if (is_kernel_context(gts))
766 return down_write_trylock(&bs->bs_kgts_sema);
768 return mutex_trylock(>s->ts_ctxlock);
771 static void gts_stolen(struct gru_thread_state *gts,
772 struct gru_blade_state *bs)
774 if (is_kernel_context(gts)) {
775 up_write(&bs->bs_kgts_sema);
776 STAT(steal_kernel_context);
778 mutex_unlock(>s->ts_ctxlock);
779 STAT(steal_user_context);
783 void gru_steal_context(struct gru_thread_state *gts)
785 struct gru_blade_state *blade;
786 struct gru_state *gru, *gru0;
787 struct gru_thread_state *ngts = NULL;
788 int ctxnum, ctxnum0, flag = 0, cbr, dsr;
791 blade_id = gts->ts_user_blade_id;
793 blade_id = uv_numa_blade_id();
794 cbr = gts->ts_cbr_au_count;
795 dsr = gts->ts_dsr_au_count;
797 blade = gru_base[blade_id];
798 spin_lock(&blade->bs_lock);
800 ctxnum = next_ctxnum(blade->bs_lru_ctxnum);
801 gru = blade->bs_lru_gru;
803 gru = next_gru(blade, gru);
804 blade->bs_lru_gru = gru;
805 blade->bs_lru_ctxnum = ctxnum;
809 if (gru_check_chiplet_assignment(gru, gts)) {
810 if (check_gru_resources(gru, cbr, dsr, GRU_NUM_CCH))
812 spin_lock(&gru->gs_lock);
813 for (; ctxnum < GRU_NUM_CCH; ctxnum++) {
814 if (flag && gru == gru0 && ctxnum == ctxnum0)
816 ngts = gru->gs_gts[ctxnum];
818 * We are grabbing locks out of order, so trylock is
819 * needed. GTSs are usually not locked, so the odds of
820 * success are high. If trylock fails, try to steal a
823 if (ngts && is_gts_stealable(ngts, blade))
827 spin_unlock(&gru->gs_lock);
828 if (ngts || (flag && gru == gru0 && ctxnum == ctxnum0))
831 if (flag && gru == gru0)
835 gru = next_gru(blade, gru);
837 spin_unlock(&blade->bs_lock);
840 gts->ustats.context_stolen++;
841 ngts->ts_steal_jiffies = jiffies;
842 gru_unload_context(ngts, is_kernel_context(ngts) ? 0 : 1);
843 gts_stolen(ngts, blade);
845 STAT(steal_context_failed);
848 "stole gid %d, ctxnum %d from gts %p. Need cb %d, ds %d;"
849 " avail cb %ld, ds %ld\n",
850 gru->gs_gid, ctxnum, ngts, cbr, dsr, hweight64(gru->gs_cbr_map),
851 hweight64(gru->gs_dsr_map));
855 * Assign a gru context.
857 static int gru_assign_context_number(struct gru_state *gru)
861 ctxnum = find_first_zero_bit(&gru->gs_context_map, GRU_NUM_CCH);
862 __set_bit(ctxnum, &gru->gs_context_map);
867 * Scan the GRUs on the local blade & assign a GRU context.
869 struct gru_state *gru_assign_gru_context(struct gru_thread_state *gts)
871 struct gru_state *gru, *grux;
872 int i, max_active_contexts;
873 int blade_id = gts->ts_user_blade_id;
876 blade_id = uv_numa_blade_id();
879 max_active_contexts = GRU_NUM_CCH;
880 for_each_gru_on_blade(grux, blade_id, i) {
881 if (!gru_check_chiplet_assignment(grux, gts))
883 if (check_gru_resources(grux, gts->ts_cbr_au_count,
884 gts->ts_dsr_au_count,
885 max_active_contexts)) {
887 max_active_contexts = grux->gs_active_contexts;
888 if (max_active_contexts == 0)
894 spin_lock(&gru->gs_lock);
895 if (!check_gru_resources(gru, gts->ts_cbr_au_count,
896 gts->ts_dsr_au_count, GRU_NUM_CCH)) {
897 spin_unlock(&gru->gs_lock);
900 reserve_gru_resources(gru, gts);
902 gts->ts_blade = gru->gs_blade_id;
903 gts->ts_ctxnum = gru_assign_context_number(gru);
904 atomic_inc(>s->ts_refcnt);
905 gru->gs_gts[gts->ts_ctxnum] = gts;
906 spin_unlock(&gru->gs_lock);
908 STAT(assign_context);
910 "gseg %p, gts %p, gid %d, ctx %d, cbr %d, dsr %d\n",
911 gseg_virtual_address(gts->ts_gru, gts->ts_ctxnum), gts,
912 gts->ts_gru->gs_gid, gts->ts_ctxnum,
913 gts->ts_cbr_au_count, gts->ts_dsr_au_count);
915 gru_dbg(grudev, "failed to allocate a GTS %s\n", "");
916 STAT(assign_context_failed);
925 * Map the user's GRU segment
927 * Note: gru segments alway mmaped on GRU_GSEG_PAGESIZE boundaries.
929 int gru_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
931 struct gru_thread_state *gts;
932 unsigned long paddr, vaddr;
934 vaddr = (unsigned long)vmf->virtual_address;
935 gru_dbg(grudev, "vma %p, vaddr 0x%lx (0x%lx)\n",
936 vma, vaddr, GSEG_BASE(vaddr));
939 /* The following check ensures vaddr is a valid address in the VMA */
940 gts = gru_find_thread_state(vma, TSID(vaddr, vma));
942 return VM_FAULT_SIGBUS;
945 mutex_lock(>s->ts_ctxlock);
948 gru_check_context_placement(gts);
951 STAT(load_user_context);
952 if (!gru_assign_gru_context(gts)) {
954 mutex_unlock(>s->ts_ctxlock);
955 set_current_state(TASK_INTERRUPTIBLE);
956 schedule_timeout(GRU_ASSIGN_DELAY); /* true hack ZZZ */
957 if (gts->ts_steal_jiffies + GRU_STEAL_DELAY < jiffies)
958 gru_steal_context(gts);
961 gru_load_context(gts);
962 paddr = gseg_physical_address(gts->ts_gru, gts->ts_ctxnum);
963 remap_pfn_range(vma, vaddr & ~(GRU_GSEG_PAGESIZE - 1),
964 paddr >> PAGE_SHIFT, GRU_GSEG_PAGESIZE,
969 mutex_unlock(>s->ts_ctxlock);
971 return VM_FAULT_NOPAGE;