1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright 2014 IBM Corp.
4 */
5
6 #include <linux/interrupt.h>
7 #include <linux/irqdomain.h>
8 #include <linux/workqueue.h>
9 #include <linux/sched.h>
10 #include <linux/wait.h>
11 #include <linux/slab.h>
12 #include <linux/pid.h>
13 #include <asm/cputable.h>
14 #include <misc/cxl-base.h>
15
16 #include "cxl.h"
17 #include "trace.h"
18
afu_irq_range_start(void)19 static int afu_irq_range_start(void)
20 {
21 if (cpu_has_feature(CPU_FTR_HVMODE))
22 return 1;
23 return 0;
24 }
25
schedule_cxl_fault(struct cxl_context * ctx,u64 dsisr,u64 dar)26 static irqreturn_t schedule_cxl_fault(struct cxl_context *ctx, u64 dsisr, u64 dar)
27 {
28 ctx->dsisr = dsisr;
29 ctx->dar = dar;
30 schedule_work(&ctx->fault_work);
31 return IRQ_HANDLED;
32 }
33
cxl_irq_psl9(int irq,struct cxl_context * ctx,struct cxl_irq_info * irq_info)34 irqreturn_t cxl_irq_psl9(int irq, struct cxl_context *ctx, struct cxl_irq_info *irq_info)
35 {
36 u64 dsisr, dar;
37
38 dsisr = irq_info->dsisr;
39 dar = irq_info->dar;
40
41 trace_cxl_psl9_irq(ctx, irq, dsisr, dar);
42
43 pr_devel("CXL interrupt %i for afu pe: %i DSISR: %#llx DAR: %#llx\n", irq, ctx->pe, dsisr, dar);
44
45 if (dsisr & CXL_PSL9_DSISR_An_TF) {
46 pr_devel("CXL interrupt: Scheduling translation fault handling for later (pe: %i)\n", ctx->pe);
47 return schedule_cxl_fault(ctx, dsisr, dar);
48 }
49
50 if (dsisr & CXL_PSL9_DSISR_An_PE)
51 return cxl_ops->handle_psl_slice_error(ctx, dsisr,
52 irq_info->errstat);
53 if (dsisr & CXL_PSL9_DSISR_An_AE) {
54 pr_devel("CXL interrupt: AFU Error 0x%016llx\n", irq_info->afu_err);
55
56 if (ctx->pending_afu_err) {
57 /*
58 * This shouldn't happen - the PSL treats these errors
59 * as fatal and will have reset the AFU, so there's not
60 * much point buffering multiple AFU errors.
61 * OTOH if we DO ever see a storm of these come in it's
62 * probably best that we log them somewhere:
63 */
64 dev_err_ratelimited(&ctx->afu->dev, "CXL AFU Error undelivered to pe %i: 0x%016llx\n",
65 ctx->pe, irq_info->afu_err);
66 } else {
67 spin_lock(&ctx->lock);
68 ctx->afu_err = irq_info->afu_err;
69 ctx->pending_afu_err = 1;
70 spin_unlock(&ctx->lock);
71
72 wake_up_all(&ctx->wq);
73 }
74
75 cxl_ops->ack_irq(ctx, CXL_PSL_TFC_An_A, 0);
76 return IRQ_HANDLED;
77 }
78 if (dsisr & CXL_PSL9_DSISR_An_OC)
79 pr_devel("CXL interrupt: OS Context Warning\n");
80
81 WARN(1, "Unhandled CXL PSL IRQ\n");
82 return IRQ_HANDLED;
83 }
84
cxl_irq_psl8(int irq,struct cxl_context * ctx,struct cxl_irq_info * irq_info)85 irqreturn_t cxl_irq_psl8(int irq, struct cxl_context *ctx, struct cxl_irq_info *irq_info)
86 {
87 u64 dsisr, dar;
88
89 dsisr = irq_info->dsisr;
90 dar = irq_info->dar;
91
92 trace_cxl_psl_irq(ctx, irq, dsisr, dar);
93
94 pr_devel("CXL interrupt %i for afu pe: %i DSISR: %#llx DAR: %#llx\n", irq, ctx->pe, dsisr, dar);
95
96 if (dsisr & CXL_PSL_DSISR_An_DS) {
97 /*
98 * We don't inherently need to sleep to handle this, but we do
99 * need to get a ref to the task's mm, which we can't do from
100 * irq context without the potential for a deadlock since it
101 * takes the task_lock. An alternate option would be to keep a
102 * reference to the task's mm the entire time it has cxl open,
103 * but to do that we need to solve the issue where we hold a
104 * ref to the mm, but the mm can hold a ref to the fd after an
105 * mmap preventing anything from being cleaned up.
106 */
107 pr_devel("Scheduling segment miss handling for later pe: %i\n", ctx->pe);
108 return schedule_cxl_fault(ctx, dsisr, dar);
109 }
110
111 if (dsisr & CXL_PSL_DSISR_An_M)
112 pr_devel("CXL interrupt: PTE not found\n");
113 if (dsisr & CXL_PSL_DSISR_An_P)
114 pr_devel("CXL interrupt: Storage protection violation\n");
115 if (dsisr & CXL_PSL_DSISR_An_A)
116 pr_devel("CXL interrupt: AFU lock access to write through or cache inhibited storage\n");
117 if (dsisr & CXL_PSL_DSISR_An_S)
118 pr_devel("CXL interrupt: Access was afu_wr or afu_zero\n");
119 if (dsisr & CXL_PSL_DSISR_An_K)
120 pr_devel("CXL interrupt: Access not permitted by virtual page class key protection\n");
121
122 if (dsisr & CXL_PSL_DSISR_An_DM) {
123 /*
124 * In some cases we might be able to handle the fault
125 * immediately if hash_page would succeed, but we still need
126 * the task's mm, which as above we can't get without a lock
127 */
128 pr_devel("Scheduling page fault handling for later pe: %i\n", ctx->pe);
129 return schedule_cxl_fault(ctx, dsisr, dar);
130 }
131 if (dsisr & CXL_PSL_DSISR_An_ST)
132 WARN(1, "CXL interrupt: Segment Table PTE not found\n");
133 if (dsisr & CXL_PSL_DSISR_An_UR)
134 pr_devel("CXL interrupt: AURP PTE not found\n");
135 if (dsisr & CXL_PSL_DSISR_An_PE)
136 return cxl_ops->handle_psl_slice_error(ctx, dsisr,
137 irq_info->errstat);
138 if (dsisr & CXL_PSL_DSISR_An_AE) {
139 pr_devel("CXL interrupt: AFU Error 0x%016llx\n", irq_info->afu_err);
140
141 if (ctx->pending_afu_err) {
142 /*
143 * This shouldn't happen - the PSL treats these errors
144 * as fatal and will have reset the AFU, so there's not
145 * much point buffering multiple AFU errors.
146 * OTOH if we DO ever see a storm of these come in it's
147 * probably best that we log them somewhere:
148 */
149 dev_err_ratelimited(&ctx->afu->dev, "CXL AFU Error "
150 "undelivered to pe %i: 0x%016llx\n",
151 ctx->pe, irq_info->afu_err);
152 } else {
153 spin_lock(&ctx->lock);
154 ctx->afu_err = irq_info->afu_err;
155 ctx->pending_afu_err = true;
156 spin_unlock(&ctx->lock);
157
158 wake_up_all(&ctx->wq);
159 }
160
161 cxl_ops->ack_irq(ctx, CXL_PSL_TFC_An_A, 0);
162 return IRQ_HANDLED;
163 }
164 if (dsisr & CXL_PSL_DSISR_An_OC)
165 pr_devel("CXL interrupt: OS Context Warning\n");
166
167 WARN(1, "Unhandled CXL PSL IRQ\n");
168 return IRQ_HANDLED;
169 }
170
cxl_irq_afu(int irq,void * data)171 static irqreturn_t cxl_irq_afu(int irq, void *data)
172 {
173 struct cxl_context *ctx = data;
174 irq_hw_number_t hwirq = irqd_to_hwirq(irq_get_irq_data(irq));
175 int irq_off, afu_irq = 0;
176 __u16 range;
177 int r;
178
179 /*
180 * Look for the interrupt number.
181 * On bare-metal, we know range 0 only contains the PSL
182 * interrupt so we could start counting at range 1 and initialize
183 * afu_irq at 1.
184 * In a guest, range 0 also contains AFU interrupts, so it must
185 * be counted for. Therefore we initialize afu_irq at 0 to take into
186 * account the PSL interrupt.
187 *
188 * For code-readability, it just seems easier to go over all
189 * the ranges on bare-metal and guest. The end result is the same.
190 */
191 for (r = 0; r < CXL_IRQ_RANGES; r++) {
192 irq_off = hwirq - ctx->irqs.offset[r];
193 range = ctx->irqs.range[r];
194 if (irq_off >= 0 && irq_off < range) {
195 afu_irq += irq_off;
196 break;
197 }
198 afu_irq += range;
199 }
200 if (unlikely(r >= CXL_IRQ_RANGES)) {
201 WARN(1, "Received AFU IRQ out of range for pe %i (virq %i hwirq %lx)\n",
202 ctx->pe, irq, hwirq);
203 return IRQ_HANDLED;
204 }
205
206 trace_cxl_afu_irq(ctx, afu_irq, irq, hwirq);
207 pr_devel("Received AFU interrupt %i for pe: %i (virq %i hwirq %lx)\n",
208 afu_irq, ctx->pe, irq, hwirq);
209
210 if (unlikely(!ctx->irq_bitmap)) {
211 WARN(1, "Received AFU IRQ for context with no IRQ bitmap\n");
212 return IRQ_HANDLED;
213 }
214 spin_lock(&ctx->lock);
215 set_bit(afu_irq - 1, ctx->irq_bitmap);
216 ctx->pending_irq = true;
217 spin_unlock(&ctx->lock);
218
219 wake_up_all(&ctx->wq);
220
221 return IRQ_HANDLED;
222 }
223
cxl_map_irq(struct cxl * adapter,irq_hw_number_t hwirq,irq_handler_t handler,void * cookie,const char * name)224 unsigned int cxl_map_irq(struct cxl *adapter, irq_hw_number_t hwirq,
225 irq_handler_t handler, void *cookie, const char *name)
226 {
227 unsigned int virq;
228 int result;
229
230 /* IRQ Domain? */
231 virq = irq_create_mapping(NULL, hwirq);
232 if (!virq) {
233 dev_warn(&adapter->dev, "cxl_map_irq: irq_create_mapping failed\n");
234 return 0;
235 }
236
237 if (cxl_ops->setup_irq)
238 cxl_ops->setup_irq(adapter, hwirq, virq);
239
240 pr_devel("hwirq %#lx mapped to virq %u\n", hwirq, virq);
241
242 result = request_irq(virq, handler, 0, name, cookie);
243 if (result) {
244 dev_warn(&adapter->dev, "cxl_map_irq: request_irq failed: %i\n", result);
245 return 0;
246 }
247
248 return virq;
249 }
250
cxl_unmap_irq(unsigned int virq,void * cookie)251 void cxl_unmap_irq(unsigned int virq, void *cookie)
252 {
253 free_irq(virq, cookie);
254 }
255
cxl_register_one_irq(struct cxl * adapter,irq_handler_t handler,void * cookie,irq_hw_number_t * dest_hwirq,unsigned int * dest_virq,const char * name)256 int cxl_register_one_irq(struct cxl *adapter,
257 irq_handler_t handler,
258 void *cookie,
259 irq_hw_number_t *dest_hwirq,
260 unsigned int *dest_virq,
261 const char *name)
262 {
263 int hwirq, virq;
264
265 if ((hwirq = cxl_ops->alloc_one_irq(adapter)) < 0)
266 return hwirq;
267
268 if (!(virq = cxl_map_irq(adapter, hwirq, handler, cookie, name)))
269 goto err;
270
271 *dest_hwirq = hwirq;
272 *dest_virq = virq;
273
274 return 0;
275
276 err:
277 cxl_ops->release_one_irq(adapter, hwirq);
278 return -ENOMEM;
279 }
280
afu_irq_name_free(struct cxl_context * ctx)281 void afu_irq_name_free(struct cxl_context *ctx)
282 {
283 struct cxl_irq_name *irq_name, *tmp;
284
285 list_for_each_entry_safe(irq_name, tmp, &ctx->irq_names, list) {
286 kfree(irq_name->name);
287 list_del(&irq_name->list);
288 kfree(irq_name);
289 }
290 }
291
afu_allocate_irqs(struct cxl_context * ctx,u32 count)292 int afu_allocate_irqs(struct cxl_context *ctx, u32 count)
293 {
294 int rc, r, i, j = 1;
295 struct cxl_irq_name *irq_name;
296 int alloc_count;
297
298 /*
299 * In native mode, range 0 is reserved for the multiplexed
300 * PSL interrupt. It has been allocated when the AFU was initialized.
301 *
302 * In a guest, the PSL interrupt is not mutliplexed, but per-context,
303 * and is the first interrupt from range 0. It still needs to be
304 * allocated, so bump the count by one.
305 */
306 if (cpu_has_feature(CPU_FTR_HVMODE))
307 alloc_count = count;
308 else
309 alloc_count = count + 1;
310
311 if ((rc = cxl_ops->alloc_irq_ranges(&ctx->irqs, ctx->afu->adapter,
312 alloc_count)))
313 return rc;
314
315 if (cpu_has_feature(CPU_FTR_HVMODE)) {
316 /* Multiplexed PSL Interrupt */
317 ctx->irqs.offset[0] = ctx->afu->native->psl_hwirq;
318 ctx->irqs.range[0] = 1;
319 }
320
321 ctx->irq_count = count;
322 ctx->irq_bitmap = bitmap_zalloc(count, GFP_KERNEL);
323 if (!ctx->irq_bitmap)
324 goto out;
325
326 /*
327 * Allocate names first. If any fail, bail out before allocating
328 * actual hardware IRQs.
329 */
330 for (r = afu_irq_range_start(); r < CXL_IRQ_RANGES; r++) {
331 for (i = 0; i < ctx->irqs.range[r]; i++) {
332 irq_name = kmalloc(sizeof(struct cxl_irq_name),
333 GFP_KERNEL);
334 if (!irq_name)
335 goto out;
336 irq_name->name = kasprintf(GFP_KERNEL, "cxl-%s-pe%i-%i",
337 dev_name(&ctx->afu->dev),
338 ctx->pe, j);
339 if (!irq_name->name) {
340 kfree(irq_name);
341 goto out;
342 }
343 /* Add to tail so next look get the correct order */
344 list_add_tail(&irq_name->list, &ctx->irq_names);
345 j++;
346 }
347 }
348 return 0;
349
350 out:
351 cxl_ops->release_irq_ranges(&ctx->irqs, ctx->afu->adapter);
352 bitmap_free(ctx->irq_bitmap);
353 afu_irq_name_free(ctx);
354 return -ENOMEM;
355 }
356
afu_register_hwirqs(struct cxl_context * ctx)357 static void afu_register_hwirqs(struct cxl_context *ctx)
358 {
359 irq_hw_number_t hwirq;
360 struct cxl_irq_name *irq_name;
361 int r, i;
362 irqreturn_t (*handler)(int irq, void *data);
363
364 /* We've allocated all memory now, so let's do the irq allocations */
365 irq_name = list_first_entry(&ctx->irq_names, struct cxl_irq_name, list);
366 for (r = afu_irq_range_start(); r < CXL_IRQ_RANGES; r++) {
367 hwirq = ctx->irqs.offset[r];
368 for (i = 0; i < ctx->irqs.range[r]; hwirq++, i++) {
369 if (r == 0 && i == 0)
370 /*
371 * The very first interrupt of range 0 is
372 * always the PSL interrupt, but we only
373 * need to connect a handler for guests,
374 * because there's one PSL interrupt per
375 * context.
376 * On bare-metal, the PSL interrupt is
377 * multiplexed and was setup when the AFU
378 * was configured.
379 */
380 handler = cxl_ops->psl_interrupt;
381 else
382 handler = cxl_irq_afu;
383 cxl_map_irq(ctx->afu->adapter, hwirq, handler, ctx,
384 irq_name->name);
385 irq_name = list_next_entry(irq_name, list);
386 }
387 }
388 }
389
afu_register_irqs(struct cxl_context * ctx,u32 count)390 int afu_register_irqs(struct cxl_context *ctx, u32 count)
391 {
392 int rc;
393
394 rc = afu_allocate_irqs(ctx, count);
395 if (rc)
396 return rc;
397
398 afu_register_hwirqs(ctx);
399 return 0;
400 }
401
afu_release_irqs(struct cxl_context * ctx,void * cookie)402 void afu_release_irqs(struct cxl_context *ctx, void *cookie)
403 {
404 irq_hw_number_t hwirq;
405 unsigned int virq;
406 int r, i;
407
408 for (r = afu_irq_range_start(); r < CXL_IRQ_RANGES; r++) {
409 hwirq = ctx->irqs.offset[r];
410 for (i = 0; i < ctx->irqs.range[r]; hwirq++, i++) {
411 virq = irq_find_mapping(NULL, hwirq);
412 if (virq)
413 cxl_unmap_irq(virq, cookie);
414 }
415 }
416
417 afu_irq_name_free(ctx);
418 cxl_ops->release_irq_ranges(&ctx->irqs, ctx->afu->adapter);
419
420 ctx->irq_count = 0;
421 }
422
cxl_afu_decode_psl_serr(struct cxl_afu * afu,u64 serr)423 void cxl_afu_decode_psl_serr(struct cxl_afu *afu, u64 serr)
424 {
425 dev_crit(&afu->dev,
426 "PSL Slice error received. Check AFU for root cause.\n");
427 dev_crit(&afu->dev, "PSL_SERR_An: 0x%016llx\n", serr);
428 if (serr & CXL_PSL_SERR_An_afuto)
429 dev_crit(&afu->dev, "AFU MMIO Timeout\n");
430 if (serr & CXL_PSL_SERR_An_afudis)
431 dev_crit(&afu->dev,
432 "MMIO targeted Accelerator that was not enabled\n");
433 if (serr & CXL_PSL_SERR_An_afuov)
434 dev_crit(&afu->dev, "AFU CTAG Overflow\n");
435 if (serr & CXL_PSL_SERR_An_badsrc)
436 dev_crit(&afu->dev, "Bad Interrupt Source\n");
437 if (serr & CXL_PSL_SERR_An_badctx)
438 dev_crit(&afu->dev, "Bad Context Handle\n");
439 if (serr & CXL_PSL_SERR_An_llcmdis)
440 dev_crit(&afu->dev, "LLCMD to Disabled AFU\n");
441 if (serr & CXL_PSL_SERR_An_llcmdto)
442 dev_crit(&afu->dev, "LLCMD Timeout to AFU\n");
443 if (serr & CXL_PSL_SERR_An_afupar)
444 dev_crit(&afu->dev, "AFU MMIO Parity Error\n");
445 if (serr & CXL_PSL_SERR_An_afudup)
446 dev_crit(&afu->dev, "AFU MMIO Duplicate CTAG Error\n");
447 if (serr & CXL_PSL_SERR_An_AE)
448 dev_crit(&afu->dev,
449 "AFU asserted JDONE with JERROR in AFU Directed Mode\n");
450 }
451