1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * SN Platform GRU Driver
4  *
5  *              FAULT HANDLER FOR GRU DETECTED TLB MISSES
6  *
7  * This file contains code that handles TLB misses within the GRU.
8  * These misses are reported either via interrupts or user polling of
9  * the user CB.
10  *
11  *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/spinlock.h>
17 #include <linux/mm.h>
18 #include <linux/hugetlb.h>
19 #include <linux/device.h>
20 #include <linux/io.h>
21 #include <linux/uaccess.h>
22 #include <linux/security.h>
23 #include <linux/sync_core.h>
24 #include <linux/prefetch.h>
25 #include "gru.h"
26 #include "grutables.h"
27 #include "grulib.h"
28 #include "gru_instructions.h"
29 #include <asm/uv/uv_hub.h>
30 
31 /* Return codes for vtop functions */
32 #define VTOP_SUCCESS               0
33 #define VTOP_INVALID               -1
34 #define VTOP_RETRY                 -2
35 
36 
37 /*
38  * Test if a physical address is a valid GRU GSEG address
39  */
is_gru_paddr(unsigned long paddr)40 static inline int is_gru_paddr(unsigned long paddr)
41 {
42 	return paddr >= gru_start_paddr && paddr < gru_end_paddr;
43 }
44 
45 /*
46  * Find the vma of a GRU segment. Caller must hold mmap_lock.
47  */
gru_find_vma(unsigned long vaddr)48 struct vm_area_struct *gru_find_vma(unsigned long vaddr)
49 {
50 	struct vm_area_struct *vma;
51 
52 	vma = vma_lookup(current->mm, vaddr);
53 	if (vma && vma->vm_ops == &gru_vm_ops)
54 		return vma;
55 	return NULL;
56 }
57 
58 /*
59  * Find and lock the gts that contains the specified user vaddr.
60  *
61  * Returns:
62  * 	- *gts with the mmap_lock locked for read and the GTS locked.
63  *	- NULL if vaddr invalid OR is not a valid GSEG vaddr.
64  */
65 
gru_find_lock_gts(unsigned long vaddr)66 static struct gru_thread_state *gru_find_lock_gts(unsigned long vaddr)
67 {
68 	struct mm_struct *mm = current->mm;
69 	struct vm_area_struct *vma;
70 	struct gru_thread_state *gts = NULL;
71 
72 	mmap_read_lock(mm);
73 	vma = gru_find_vma(vaddr);
74 	if (vma)
75 		gts = gru_find_thread_state(vma, TSID(vaddr, vma));
76 	if (gts)
77 		mutex_lock(&gts->ts_ctxlock);
78 	else
79 		mmap_read_unlock(mm);
80 	return gts;
81 }
82 
gru_alloc_locked_gts(unsigned long vaddr)83 static struct gru_thread_state *gru_alloc_locked_gts(unsigned long vaddr)
84 {
85 	struct mm_struct *mm = current->mm;
86 	struct vm_area_struct *vma;
87 	struct gru_thread_state *gts = ERR_PTR(-EINVAL);
88 
89 	mmap_write_lock(mm);
90 	vma = gru_find_vma(vaddr);
91 	if (!vma)
92 		goto err;
93 
94 	gts = gru_alloc_thread_state(vma, TSID(vaddr, vma));
95 	if (IS_ERR(gts))
96 		goto err;
97 	mutex_lock(&gts->ts_ctxlock);
98 	mmap_write_downgrade(mm);
99 	return gts;
100 
101 err:
102 	mmap_write_unlock(mm);
103 	return gts;
104 }
105 
106 /*
107  * Unlock a GTS that was previously locked with gru_find_lock_gts().
108  */
gru_unlock_gts(struct gru_thread_state * gts)109 static void gru_unlock_gts(struct gru_thread_state *gts)
110 {
111 	mutex_unlock(&gts->ts_ctxlock);
112 	mmap_read_unlock(current->mm);
113 }
114 
115 /*
116  * Set a CB.istatus to active using a user virtual address. This must be done
117  * just prior to a TFH RESTART. The new cb.istatus is an in-cache status ONLY.
118  * If the line is evicted, the status may be lost. The in-cache update
119  * is necessary to prevent the user from seeing a stale cb.istatus that will
120  * change as soon as the TFH restart is complete. Races may cause an
121  * occasional failure to clear the cb.istatus, but that is ok.
122  */
gru_cb_set_istatus_active(struct gru_instruction_bits * cbk)123 static void gru_cb_set_istatus_active(struct gru_instruction_bits *cbk)
124 {
125 	if (cbk) {
126 		cbk->istatus = CBS_ACTIVE;
127 	}
128 }
129 
130 /*
131  * Read & clear a TFM
132  *
133  * The GRU has an array of fault maps. A map is private to a cpu
134  * Only one cpu will be accessing a cpu's fault map.
135  *
136  * This function scans the cpu-private fault map & clears all bits that
137  * are set. The function returns a bitmap that indicates the bits that
138  * were cleared. Note that sense the maps may be updated asynchronously by
139  * the GRU, atomic operations must be used to clear bits.
140  */
get_clear_fault_map(struct gru_state * gru,struct gru_tlb_fault_map * imap,struct gru_tlb_fault_map * dmap)141 static void get_clear_fault_map(struct gru_state *gru,
142 				struct gru_tlb_fault_map *imap,
143 				struct gru_tlb_fault_map *dmap)
144 {
145 	unsigned long i, k;
146 	struct gru_tlb_fault_map *tfm;
147 
148 	tfm = get_tfm_for_cpu(gru, gru_cpu_fault_map_id());
149 	prefetchw(tfm);		/* Helps on hardware, required for emulator */
150 	for (i = 0; i < BITS_TO_LONGS(GRU_NUM_CBE); i++) {
151 		k = tfm->fault_bits[i];
152 		if (k)
153 			k = xchg(&tfm->fault_bits[i], 0UL);
154 		imap->fault_bits[i] = k;
155 		k = tfm->done_bits[i];
156 		if (k)
157 			k = xchg(&tfm->done_bits[i], 0UL);
158 		dmap->fault_bits[i] = k;
159 	}
160 
161 	/*
162 	 * Not functionally required but helps performance. (Required
163 	 * on emulator)
164 	 */
165 	gru_flush_cache(tfm);
166 }
167 
168 /*
169  * Atomic (interrupt context) & non-atomic (user context) functions to
170  * convert a vaddr into a physical address. The size of the page
171  * is returned in pageshift.
172  * 	returns:
173  * 		  0 - successful
174  * 		< 0 - error code
175  * 		  1 - (atomic only) try again in non-atomic context
176  */
non_atomic_pte_lookup(struct vm_area_struct * vma,unsigned long vaddr,int write,unsigned long * paddr,int * pageshift)177 static int non_atomic_pte_lookup(struct vm_area_struct *vma,
178 				 unsigned long vaddr, int write,
179 				 unsigned long *paddr, int *pageshift)
180 {
181 	struct page *page;
182 
183 #ifdef CONFIG_HUGETLB_PAGE
184 	*pageshift = is_vm_hugetlb_page(vma) ? HPAGE_SHIFT : PAGE_SHIFT;
185 #else
186 	*pageshift = PAGE_SHIFT;
187 #endif
188 	if (get_user_pages(vaddr, 1, write ? FOLL_WRITE : 0, &page) <= 0)
189 		return -EFAULT;
190 	*paddr = page_to_phys(page);
191 	put_page(page);
192 	return 0;
193 }
194 
195 /*
196  * atomic_pte_lookup
197  *
198  * Convert a user virtual address to a physical address
199  * Only supports Intel large pages (2MB only) on x86_64.
200  *	ZZZ - hugepage support is incomplete
201  *
202  * NOTE: mmap_lock is already held on entry to this function. This
203  * guarantees existence of the page tables.
204  */
atomic_pte_lookup(struct vm_area_struct * vma,unsigned long vaddr,int write,unsigned long * paddr,int * pageshift)205 static int atomic_pte_lookup(struct vm_area_struct *vma, unsigned long vaddr,
206 	int write, unsigned long *paddr, int *pageshift)
207 {
208 	pgd_t *pgdp;
209 	p4d_t *p4dp;
210 	pud_t *pudp;
211 	pmd_t *pmdp;
212 	pte_t pte;
213 
214 	pgdp = pgd_offset(vma->vm_mm, vaddr);
215 	if (unlikely(pgd_none(*pgdp)))
216 		goto err;
217 
218 	p4dp = p4d_offset(pgdp, vaddr);
219 	if (unlikely(p4d_none(*p4dp)))
220 		goto err;
221 
222 	pudp = pud_offset(p4dp, vaddr);
223 	if (unlikely(pud_none(*pudp)))
224 		goto err;
225 
226 	pmdp = pmd_offset(pudp, vaddr);
227 	if (unlikely(pmd_none(*pmdp)))
228 		goto err;
229 #ifdef CONFIG_X86_64
230 	if (unlikely(pmd_large(*pmdp)))
231 		pte = ptep_get((pte_t *)pmdp);
232 	else
233 #endif
234 		pte = *pte_offset_kernel(pmdp, vaddr);
235 
236 	if (unlikely(!pte_present(pte) ||
237 		     (write && (!pte_write(pte) || !pte_dirty(pte)))))
238 		return 1;
239 
240 	*paddr = pte_pfn(pte) << PAGE_SHIFT;
241 #ifdef CONFIG_HUGETLB_PAGE
242 	*pageshift = is_vm_hugetlb_page(vma) ? HPAGE_SHIFT : PAGE_SHIFT;
243 #else
244 	*pageshift = PAGE_SHIFT;
245 #endif
246 	return 0;
247 
248 err:
249 	return 1;
250 }
251 
gru_vtop(struct gru_thread_state * gts,unsigned long vaddr,int write,int atomic,unsigned long * gpa,int * pageshift)252 static int gru_vtop(struct gru_thread_state *gts, unsigned long vaddr,
253 		    int write, int atomic, unsigned long *gpa, int *pageshift)
254 {
255 	struct mm_struct *mm = gts->ts_mm;
256 	struct vm_area_struct *vma;
257 	unsigned long paddr;
258 	int ret, ps;
259 
260 	vma = find_vma(mm, vaddr);
261 	if (!vma)
262 		goto inval;
263 
264 	/*
265 	 * Atomic lookup is faster & usually works even if called in non-atomic
266 	 * context.
267 	 */
268 	rmb();	/* Must/check ms_range_active before loading PTEs */
269 	ret = atomic_pte_lookup(vma, vaddr, write, &paddr, &ps);
270 	if (ret) {
271 		if (atomic)
272 			goto upm;
273 		if (non_atomic_pte_lookup(vma, vaddr, write, &paddr, &ps))
274 			goto inval;
275 	}
276 	if (is_gru_paddr(paddr))
277 		goto inval;
278 	paddr = paddr & ~((1UL << ps) - 1);
279 	*gpa = uv_soc_phys_ram_to_gpa(paddr);
280 	*pageshift = ps;
281 	return VTOP_SUCCESS;
282 
283 inval:
284 	return VTOP_INVALID;
285 upm:
286 	return VTOP_RETRY;
287 }
288 
289 
290 /*
291  * Flush a CBE from cache. The CBE is clean in the cache. Dirty the
292  * CBE cacheline so that the line will be written back to home agent.
293  * Otherwise the line may be silently dropped. This has no impact
294  * except on performance.
295  */
gru_flush_cache_cbe(struct gru_control_block_extended * cbe)296 static void gru_flush_cache_cbe(struct gru_control_block_extended *cbe)
297 {
298 	if (unlikely(cbe)) {
299 		cbe->cbrexecstatus = 0;         /* make CL dirty */
300 		gru_flush_cache(cbe);
301 	}
302 }
303 
304 /*
305  * Preload the TLB with entries that may be required. Currently, preloading
306  * is implemented only for BCOPY. Preload  <tlb_preload_count> pages OR to
307  * the end of the bcopy tranfer, whichever is smaller.
308  */
gru_preload_tlb(struct gru_state * gru,struct gru_thread_state * gts,int atomic,unsigned long fault_vaddr,int asid,int write,unsigned char tlb_preload_count,struct gru_tlb_fault_handle * tfh,struct gru_control_block_extended * cbe)309 static void gru_preload_tlb(struct gru_state *gru,
310 			struct gru_thread_state *gts, int atomic,
311 			unsigned long fault_vaddr, int asid, int write,
312 			unsigned char tlb_preload_count,
313 			struct gru_tlb_fault_handle *tfh,
314 			struct gru_control_block_extended *cbe)
315 {
316 	unsigned long vaddr = 0, gpa;
317 	int ret, pageshift;
318 
319 	if (cbe->opccpy != OP_BCOPY)
320 		return;
321 
322 	if (fault_vaddr == cbe->cbe_baddr0)
323 		vaddr = fault_vaddr + GRU_CACHE_LINE_BYTES * cbe->cbe_src_cl - 1;
324 	else if (fault_vaddr == cbe->cbe_baddr1)
325 		vaddr = fault_vaddr + (1 << cbe->xtypecpy) * cbe->cbe_nelemcur - 1;
326 
327 	fault_vaddr &= PAGE_MASK;
328 	vaddr &= PAGE_MASK;
329 	vaddr = min(vaddr, fault_vaddr + tlb_preload_count * PAGE_SIZE);
330 
331 	while (vaddr > fault_vaddr) {
332 		ret = gru_vtop(gts, vaddr, write, atomic, &gpa, &pageshift);
333 		if (ret || tfh_write_only(tfh, gpa, GAA_RAM, vaddr, asid, write,
334 					  GRU_PAGESIZE(pageshift)))
335 			return;
336 		gru_dbg(grudev,
337 			"%s: gid %d, gts 0x%p, tfh 0x%p, vaddr 0x%lx, asid 0x%x, rw %d, ps %d, gpa 0x%lx\n",
338 			atomic ? "atomic" : "non-atomic", gru->gs_gid, gts, tfh,
339 			vaddr, asid, write, pageshift, gpa);
340 		vaddr -= PAGE_SIZE;
341 		STAT(tlb_preload_page);
342 	}
343 }
344 
345 /*
346  * Drop a TLB entry into the GRU. The fault is described by info in an TFH.
347  *	Input:
348  *		cb    Address of user CBR. Null if not running in user context
349  * 	Return:
350  * 		  0 = dropin, exception, or switch to UPM successful
351  * 		  1 = range invalidate active
352  * 		< 0 = error code
353  *
354  */
gru_try_dropin(struct gru_state * gru,struct gru_thread_state * gts,struct gru_tlb_fault_handle * tfh,struct gru_instruction_bits * cbk)355 static int gru_try_dropin(struct gru_state *gru,
356 			  struct gru_thread_state *gts,
357 			  struct gru_tlb_fault_handle *tfh,
358 			  struct gru_instruction_bits *cbk)
359 {
360 	struct gru_control_block_extended *cbe = NULL;
361 	unsigned char tlb_preload_count = gts->ts_tlb_preload_count;
362 	int pageshift = 0, asid, write, ret, atomic = !cbk, indexway;
363 	unsigned long gpa = 0, vaddr = 0;
364 
365 	/*
366 	 * NOTE: The GRU contains magic hardware that eliminates races between
367 	 * TLB invalidates and TLB dropins. If an invalidate occurs
368 	 * in the window between reading the TFH and the subsequent TLB dropin,
369 	 * the dropin is ignored. This eliminates the need for additional locks.
370 	 */
371 
372 	/*
373 	 * Prefetch the CBE if doing TLB preloading
374 	 */
375 	if (unlikely(tlb_preload_count)) {
376 		cbe = gru_tfh_to_cbe(tfh);
377 		prefetchw(cbe);
378 	}
379 
380 	/*
381 	 * Error if TFH state is IDLE or FMM mode & the user issuing a UPM call.
382 	 * Might be a hardware race OR a stupid user. Ignore FMM because FMM
383 	 * is a transient state.
384 	 */
385 	if (tfh->status != TFHSTATUS_EXCEPTION) {
386 		gru_flush_cache(tfh);
387 		sync_core();
388 		if (tfh->status != TFHSTATUS_EXCEPTION)
389 			goto failnoexception;
390 		STAT(tfh_stale_on_fault);
391 	}
392 	if (tfh->state == TFHSTATE_IDLE)
393 		goto failidle;
394 	if (tfh->state == TFHSTATE_MISS_FMM && cbk)
395 		goto failfmm;
396 
397 	write = (tfh->cause & TFHCAUSE_TLB_MOD) != 0;
398 	vaddr = tfh->missvaddr;
399 	asid = tfh->missasid;
400 	indexway = tfh->indexway;
401 	if (asid == 0)
402 		goto failnoasid;
403 
404 	rmb();	/* TFH must be cache resident before reading ms_range_active */
405 
406 	/*
407 	 * TFH is cache resident - at least briefly. Fail the dropin
408 	 * if a range invalidate is active.
409 	 */
410 	if (atomic_read(&gts->ts_gms->ms_range_active))
411 		goto failactive;
412 
413 	ret = gru_vtop(gts, vaddr, write, atomic, &gpa, &pageshift);
414 	if (ret == VTOP_INVALID)
415 		goto failinval;
416 	if (ret == VTOP_RETRY)
417 		goto failupm;
418 
419 	if (!(gts->ts_sizeavail & GRU_SIZEAVAIL(pageshift))) {
420 		gts->ts_sizeavail |= GRU_SIZEAVAIL(pageshift);
421 		if (atomic || !gru_update_cch(gts)) {
422 			gts->ts_force_cch_reload = 1;
423 			goto failupm;
424 		}
425 	}
426 
427 	if (unlikely(cbe) && pageshift == PAGE_SHIFT) {
428 		gru_preload_tlb(gru, gts, atomic, vaddr, asid, write, tlb_preload_count, tfh, cbe);
429 		gru_flush_cache_cbe(cbe);
430 	}
431 
432 	gru_cb_set_istatus_active(cbk);
433 	gts->ustats.tlbdropin++;
434 	tfh_write_restart(tfh, gpa, GAA_RAM, vaddr, asid, write,
435 			  GRU_PAGESIZE(pageshift));
436 	gru_dbg(grudev,
437 		"%s: gid %d, gts 0x%p, tfh 0x%p, vaddr 0x%lx, asid 0x%x, indexway 0x%x,"
438 		" rw %d, ps %d, gpa 0x%lx\n",
439 		atomic ? "atomic" : "non-atomic", gru->gs_gid, gts, tfh, vaddr, asid,
440 		indexway, write, pageshift, gpa);
441 	STAT(tlb_dropin);
442 	return 0;
443 
444 failnoasid:
445 	/* No asid (delayed unload). */
446 	STAT(tlb_dropin_fail_no_asid);
447 	gru_dbg(grudev, "FAILED no_asid tfh: 0x%p, vaddr 0x%lx\n", tfh, vaddr);
448 	if (!cbk)
449 		tfh_user_polling_mode(tfh);
450 	else
451 		gru_flush_cache(tfh);
452 	gru_flush_cache_cbe(cbe);
453 	return -EAGAIN;
454 
455 failupm:
456 	/* Atomic failure switch CBR to UPM */
457 	tfh_user_polling_mode(tfh);
458 	gru_flush_cache_cbe(cbe);
459 	STAT(tlb_dropin_fail_upm);
460 	gru_dbg(grudev, "FAILED upm tfh: 0x%p, vaddr 0x%lx\n", tfh, vaddr);
461 	return 1;
462 
463 failfmm:
464 	/* FMM state on UPM call */
465 	gru_flush_cache(tfh);
466 	gru_flush_cache_cbe(cbe);
467 	STAT(tlb_dropin_fail_fmm);
468 	gru_dbg(grudev, "FAILED fmm tfh: 0x%p, state %d\n", tfh, tfh->state);
469 	return 0;
470 
471 failnoexception:
472 	/* TFH status did not show exception pending */
473 	gru_flush_cache(tfh);
474 	gru_flush_cache_cbe(cbe);
475 	if (cbk)
476 		gru_flush_cache(cbk);
477 	STAT(tlb_dropin_fail_no_exception);
478 	gru_dbg(grudev, "FAILED non-exception tfh: 0x%p, status %d, state %d\n",
479 		tfh, tfh->status, tfh->state);
480 	return 0;
481 
482 failidle:
483 	/* TFH state was idle  - no miss pending */
484 	gru_flush_cache(tfh);
485 	gru_flush_cache_cbe(cbe);
486 	if (cbk)
487 		gru_flush_cache(cbk);
488 	STAT(tlb_dropin_fail_idle);
489 	gru_dbg(grudev, "FAILED idle tfh: 0x%p, state %d\n", tfh, tfh->state);
490 	return 0;
491 
492 failinval:
493 	/* All errors (atomic & non-atomic) switch CBR to EXCEPTION state */
494 	tfh_exception(tfh);
495 	gru_flush_cache_cbe(cbe);
496 	STAT(tlb_dropin_fail_invalid);
497 	gru_dbg(grudev, "FAILED inval tfh: 0x%p, vaddr 0x%lx\n", tfh, vaddr);
498 	return -EFAULT;
499 
500 failactive:
501 	/* Range invalidate active. Switch to UPM iff atomic */
502 	if (!cbk)
503 		tfh_user_polling_mode(tfh);
504 	else
505 		gru_flush_cache(tfh);
506 	gru_flush_cache_cbe(cbe);
507 	STAT(tlb_dropin_fail_range_active);
508 	gru_dbg(grudev, "FAILED range active: tfh 0x%p, vaddr 0x%lx\n",
509 		tfh, vaddr);
510 	return 1;
511 }
512 
513 /*
514  * Process an external interrupt from the GRU. This interrupt is
515  * caused by a TLB miss.
516  * Note that this is the interrupt handler that is registered with linux
517  * interrupt handlers.
518  */
gru_intr(int chiplet,int blade)519 static irqreturn_t gru_intr(int chiplet, int blade)
520 {
521 	struct gru_state *gru;
522 	struct gru_tlb_fault_map imap, dmap;
523 	struct gru_thread_state *gts;
524 	struct gru_tlb_fault_handle *tfh = NULL;
525 	struct completion *cmp;
526 	int cbrnum, ctxnum;
527 
528 	STAT(intr);
529 
530 	gru = &gru_base[blade]->bs_grus[chiplet];
531 	if (!gru) {
532 		dev_err(grudev, "GRU: invalid interrupt: cpu %d, chiplet %d\n",
533 			raw_smp_processor_id(), chiplet);
534 		return IRQ_NONE;
535 	}
536 	get_clear_fault_map(gru, &imap, &dmap);
537 	gru_dbg(grudev,
538 		"cpu %d, chiplet %d, gid %d, imap %016lx %016lx, dmap %016lx %016lx\n",
539 		smp_processor_id(), chiplet, gru->gs_gid,
540 		imap.fault_bits[0], imap.fault_bits[1],
541 		dmap.fault_bits[0], dmap.fault_bits[1]);
542 
543 	for_each_cbr_in_tfm(cbrnum, dmap.fault_bits) {
544 		STAT(intr_cbr);
545 		cmp = gru->gs_blade->bs_async_wq;
546 		if (cmp)
547 			complete(cmp);
548 		gru_dbg(grudev, "gid %d, cbr_done %d, done %d\n",
549 			gru->gs_gid, cbrnum, cmp ? cmp->done : -1);
550 	}
551 
552 	for_each_cbr_in_tfm(cbrnum, imap.fault_bits) {
553 		STAT(intr_tfh);
554 		tfh = get_tfh_by_index(gru, cbrnum);
555 		prefetchw(tfh);	/* Helps on hdw, required for emulator */
556 
557 		/*
558 		 * When hardware sets a bit in the faultmap, it implicitly
559 		 * locks the GRU context so that it cannot be unloaded.
560 		 * The gts cannot change until a TFH start/writestart command
561 		 * is issued.
562 		 */
563 		ctxnum = tfh->ctxnum;
564 		gts = gru->gs_gts[ctxnum];
565 
566 		/* Spurious interrupts can cause this. Ignore. */
567 		if (!gts) {
568 			STAT(intr_spurious);
569 			continue;
570 		}
571 
572 		/*
573 		 * This is running in interrupt context. Trylock the mmap_lock.
574 		 * If it fails, retry the fault in user context.
575 		 */
576 		gts->ustats.fmm_tlbmiss++;
577 		if (!gts->ts_force_cch_reload &&
578 					mmap_read_trylock(gts->ts_mm)) {
579 			gru_try_dropin(gru, gts, tfh, NULL);
580 			mmap_read_unlock(gts->ts_mm);
581 		} else {
582 			tfh_user_polling_mode(tfh);
583 			STAT(intr_mm_lock_failed);
584 		}
585 	}
586 	return IRQ_HANDLED;
587 }
588 
gru0_intr(int irq,void * dev_id)589 irqreturn_t gru0_intr(int irq, void *dev_id)
590 {
591 	return gru_intr(0, uv_numa_blade_id());
592 }
593 
gru1_intr(int irq,void * dev_id)594 irqreturn_t gru1_intr(int irq, void *dev_id)
595 {
596 	return gru_intr(1, uv_numa_blade_id());
597 }
598 
gru_intr_mblade(int irq,void * dev_id)599 irqreturn_t gru_intr_mblade(int irq, void *dev_id)
600 {
601 	int blade;
602 
603 	for_each_possible_blade(blade) {
604 		if (uv_blade_nr_possible_cpus(blade))
605 			continue;
606 		gru_intr(0, blade);
607 		gru_intr(1, blade);
608 	}
609 	return IRQ_HANDLED;
610 }
611 
612 
gru_user_dropin(struct gru_thread_state * gts,struct gru_tlb_fault_handle * tfh,void * cb)613 static int gru_user_dropin(struct gru_thread_state *gts,
614 			   struct gru_tlb_fault_handle *tfh,
615 			   void *cb)
616 {
617 	struct gru_mm_struct *gms = gts->ts_gms;
618 	int ret;
619 
620 	gts->ustats.upm_tlbmiss++;
621 	while (1) {
622 		wait_event(gms->ms_wait_queue,
623 			   atomic_read(&gms->ms_range_active) == 0);
624 		prefetchw(tfh);	/* Helps on hdw, required for emulator */
625 		ret = gru_try_dropin(gts->ts_gru, gts, tfh, cb);
626 		if (ret <= 0)
627 			return ret;
628 		STAT(call_os_wait_queue);
629 	}
630 }
631 
632 /*
633  * This interface is called as a result of a user detecting a "call OS" bit
634  * in a user CB. Normally means that a TLB fault has occurred.
635  * 	cb - user virtual address of the CB
636  */
gru_handle_user_call_os(unsigned long cb)637 int gru_handle_user_call_os(unsigned long cb)
638 {
639 	struct gru_tlb_fault_handle *tfh;
640 	struct gru_thread_state *gts;
641 	void *cbk;
642 	int ucbnum, cbrnum, ret = -EINVAL;
643 
644 	STAT(call_os);
645 
646 	/* sanity check the cb pointer */
647 	ucbnum = get_cb_number((void *)cb);
648 	if ((cb & (GRU_HANDLE_STRIDE - 1)) || ucbnum >= GRU_NUM_CB)
649 		return -EINVAL;
650 
651 again:
652 	gts = gru_find_lock_gts(cb);
653 	if (!gts)
654 		return -EINVAL;
655 	gru_dbg(grudev, "address 0x%lx, gid %d, gts 0x%p\n", cb, gts->ts_gru ? gts->ts_gru->gs_gid : -1, gts);
656 
657 	if (ucbnum >= gts->ts_cbr_au_count * GRU_CBR_AU_SIZE)
658 		goto exit;
659 
660 	if (gru_check_context_placement(gts)) {
661 		gru_unlock_gts(gts);
662 		gru_unload_context(gts, 1);
663 		goto again;
664 	}
665 
666 	/*
667 	 * CCH may contain stale data if ts_force_cch_reload is set.
668 	 */
669 	if (gts->ts_gru && gts->ts_force_cch_reload) {
670 		gts->ts_force_cch_reload = 0;
671 		gru_update_cch(gts);
672 	}
673 
674 	ret = -EAGAIN;
675 	cbrnum = thread_cbr_number(gts, ucbnum);
676 	if (gts->ts_gru) {
677 		tfh = get_tfh_by_index(gts->ts_gru, cbrnum);
678 		cbk = get_gseg_base_address_cb(gts->ts_gru->gs_gru_base_vaddr,
679 				gts->ts_ctxnum, ucbnum);
680 		ret = gru_user_dropin(gts, tfh, cbk);
681 	}
682 exit:
683 	gru_unlock_gts(gts);
684 	return ret;
685 }
686 
687 /*
688  * Fetch the exception detail information for a CB that terminated with
689  * an exception.
690  */
gru_get_exception_detail(unsigned long arg)691 int gru_get_exception_detail(unsigned long arg)
692 {
693 	struct control_block_extended_exc_detail excdet;
694 	struct gru_control_block_extended *cbe;
695 	struct gru_thread_state *gts;
696 	int ucbnum, cbrnum, ret;
697 
698 	STAT(user_exception);
699 	if (copy_from_user(&excdet, (void __user *)arg, sizeof(excdet)))
700 		return -EFAULT;
701 
702 	gts = gru_find_lock_gts(excdet.cb);
703 	if (!gts)
704 		return -EINVAL;
705 
706 	gru_dbg(grudev, "address 0x%lx, gid %d, gts 0x%p\n", excdet.cb, gts->ts_gru ? gts->ts_gru->gs_gid : -1, gts);
707 	ucbnum = get_cb_number((void *)excdet.cb);
708 	if (ucbnum >= gts->ts_cbr_au_count * GRU_CBR_AU_SIZE) {
709 		ret = -EINVAL;
710 	} else if (gts->ts_gru) {
711 		cbrnum = thread_cbr_number(gts, ucbnum);
712 		cbe = get_cbe_by_index(gts->ts_gru, cbrnum);
713 		gru_flush_cache(cbe);	/* CBE not coherent */
714 		sync_core();		/* make sure we are have current data */
715 		excdet.opc = cbe->opccpy;
716 		excdet.exopc = cbe->exopccpy;
717 		excdet.ecause = cbe->ecause;
718 		excdet.exceptdet0 = cbe->idef1upd;
719 		excdet.exceptdet1 = cbe->idef3upd;
720 		excdet.cbrstate = cbe->cbrstate;
721 		excdet.cbrexecstatus = cbe->cbrexecstatus;
722 		gru_flush_cache_cbe(cbe);
723 		ret = 0;
724 	} else {
725 		ret = -EAGAIN;
726 	}
727 	gru_unlock_gts(gts);
728 
729 	gru_dbg(grudev,
730 		"cb 0x%lx, op %d, exopc %d, cbrstate %d, cbrexecstatus 0x%x, ecause 0x%x, "
731 		"exdet0 0x%lx, exdet1 0x%x\n",
732 		excdet.cb, excdet.opc, excdet.exopc, excdet.cbrstate, excdet.cbrexecstatus,
733 		excdet.ecause, excdet.exceptdet0, excdet.exceptdet1);
734 	if (!ret && copy_to_user((void __user *)arg, &excdet, sizeof(excdet)))
735 		ret = -EFAULT;
736 	return ret;
737 }
738 
739 /*
740  * User request to unload a context. Content is saved for possible reload.
741  */
gru_unload_all_contexts(void)742 static int gru_unload_all_contexts(void)
743 {
744 	struct gru_thread_state *gts;
745 	struct gru_state *gru;
746 	int gid, ctxnum;
747 
748 	if (!capable(CAP_SYS_ADMIN))
749 		return -EPERM;
750 	foreach_gid(gid) {
751 		gru = GID_TO_GRU(gid);
752 		spin_lock(&gru->gs_lock);
753 		for (ctxnum = 0; ctxnum < GRU_NUM_CCH; ctxnum++) {
754 			gts = gru->gs_gts[ctxnum];
755 			if (gts && mutex_trylock(&gts->ts_ctxlock)) {
756 				spin_unlock(&gru->gs_lock);
757 				gru_unload_context(gts, 1);
758 				mutex_unlock(&gts->ts_ctxlock);
759 				spin_lock(&gru->gs_lock);
760 			}
761 		}
762 		spin_unlock(&gru->gs_lock);
763 	}
764 	return 0;
765 }
766 
gru_user_unload_context(unsigned long arg)767 int gru_user_unload_context(unsigned long arg)
768 {
769 	struct gru_thread_state *gts;
770 	struct gru_unload_context_req req;
771 
772 	STAT(user_unload_context);
773 	if (copy_from_user(&req, (void __user *)arg, sizeof(req)))
774 		return -EFAULT;
775 
776 	gru_dbg(grudev, "gseg 0x%lx\n", req.gseg);
777 
778 	if (!req.gseg)
779 		return gru_unload_all_contexts();
780 
781 	gts = gru_find_lock_gts(req.gseg);
782 	if (!gts)
783 		return -EINVAL;
784 
785 	if (gts->ts_gru)
786 		gru_unload_context(gts, 1);
787 	gru_unlock_gts(gts);
788 
789 	return 0;
790 }
791 
792 /*
793  * User request to flush a range of virtual addresses from the GRU TLB
794  * (Mainly for testing).
795  */
gru_user_flush_tlb(unsigned long arg)796 int gru_user_flush_tlb(unsigned long arg)
797 {
798 	struct gru_thread_state *gts;
799 	struct gru_flush_tlb_req req;
800 	struct gru_mm_struct *gms;
801 
802 	STAT(user_flush_tlb);
803 	if (copy_from_user(&req, (void __user *)arg, sizeof(req)))
804 		return -EFAULT;
805 
806 	gru_dbg(grudev, "gseg 0x%lx, vaddr 0x%lx, len 0x%lx\n", req.gseg,
807 		req.vaddr, req.len);
808 
809 	gts = gru_find_lock_gts(req.gseg);
810 	if (!gts)
811 		return -EINVAL;
812 
813 	gms = gts->ts_gms;
814 	gru_unlock_gts(gts);
815 	gru_flush_tlb_range(gms, req.vaddr, req.len);
816 
817 	return 0;
818 }
819 
820 /*
821  * Fetch GSEG statisticss
822  */
gru_get_gseg_statistics(unsigned long arg)823 long gru_get_gseg_statistics(unsigned long arg)
824 {
825 	struct gru_thread_state *gts;
826 	struct gru_get_gseg_statistics_req req;
827 
828 	if (copy_from_user(&req, (void __user *)arg, sizeof(req)))
829 		return -EFAULT;
830 
831 	/*
832 	 * The library creates arrays of contexts for threaded programs.
833 	 * If no gts exists in the array, the context has never been used & all
834 	 * statistics are implicitly 0.
835 	 */
836 	gts = gru_find_lock_gts(req.gseg);
837 	if (gts) {
838 		memcpy(&req.stats, &gts->ustats, sizeof(gts->ustats));
839 		gru_unlock_gts(gts);
840 	} else {
841 		memset(&req.stats, 0, sizeof(gts->ustats));
842 	}
843 
844 	if (copy_to_user((void __user *)arg, &req, sizeof(req)))
845 		return -EFAULT;
846 
847 	return 0;
848 }
849 
850 /*
851  * Register the current task as the user of the GSEG slice.
852  * Needed for TLB fault interrupt targeting.
853  */
gru_set_context_option(unsigned long arg)854 int gru_set_context_option(unsigned long arg)
855 {
856 	struct gru_thread_state *gts;
857 	struct gru_set_context_option_req req;
858 	int ret = 0;
859 
860 	STAT(set_context_option);
861 	if (copy_from_user(&req, (void __user *)arg, sizeof(req)))
862 		return -EFAULT;
863 	gru_dbg(grudev, "op %d, gseg 0x%lx, value1 0x%lx\n", req.op, req.gseg, req.val1);
864 
865 	gts = gru_find_lock_gts(req.gseg);
866 	if (!gts) {
867 		gts = gru_alloc_locked_gts(req.gseg);
868 		if (IS_ERR(gts))
869 			return PTR_ERR(gts);
870 	}
871 
872 	switch (req.op) {
873 	case sco_blade_chiplet:
874 		/* Select blade/chiplet for GRU context */
875 		if (req.val0 < -1 || req.val0 >= GRU_CHIPLETS_PER_HUB ||
876 		    req.val1 < -1 || req.val1 >= GRU_MAX_BLADES ||
877 		    (req.val1 >= 0 && !gru_base[req.val1])) {
878 			ret = -EINVAL;
879 		} else {
880 			gts->ts_user_blade_id = req.val1;
881 			gts->ts_user_chiplet_id = req.val0;
882 			if (gru_check_context_placement(gts)) {
883 				gru_unlock_gts(gts);
884 				gru_unload_context(gts, 1);
885 				return ret;
886 			}
887 		}
888 		break;
889 	case sco_gseg_owner:
890  		/* Register the current task as the GSEG owner */
891 		gts->ts_tgid_owner = current->tgid;
892 		break;
893 	case sco_cch_req_slice:
894  		/* Set the CCH slice option */
895 		gts->ts_cch_req_slice = req.val1 & 3;
896 		break;
897 	default:
898 		ret = -EINVAL;
899 	}
900 	gru_unlock_gts(gts);
901 
902 	return ret;
903 }
904