xref: /openbmc/linux/drivers/crypto/caam/jr.c (revision 4a3fad70)
1 /*
2  * CAAM/SEC 4.x transport/backend driver
3  * JobR backend functionality
4  *
5  * Copyright 2008-2012 Freescale Semiconductor, Inc.
6  */
7 
8 #include <linux/of_irq.h>
9 #include <linux/of_address.h>
10 
11 #include "compat.h"
12 #include "ctrl.h"
13 #include "regs.h"
14 #include "jr.h"
15 #include "desc.h"
16 #include "intern.h"
17 
18 struct jr_driver_data {
19 	/* List of Physical JobR's with the Driver */
20 	struct list_head	jr_list;
21 	spinlock_t		jr_alloc_lock;	/* jr_list lock */
22 } ____cacheline_aligned;
23 
24 static struct jr_driver_data driver_data;
25 
26 static int caam_reset_hw_jr(struct device *dev)
27 {
28 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
29 	unsigned int timeout = 100000;
30 
31 	/*
32 	 * mask interrupts since we are going to poll
33 	 * for reset completion status
34 	 */
35 	clrsetbits_32(&jrp->rregs->rconfig_lo, 0, JRCFG_IMSK);
36 
37 	/* initiate flush (required prior to reset) */
38 	wr_reg32(&jrp->rregs->jrcommand, JRCR_RESET);
39 	while (((rd_reg32(&jrp->rregs->jrintstatus) & JRINT_ERR_HALT_MASK) ==
40 		JRINT_ERR_HALT_INPROGRESS) && --timeout)
41 		cpu_relax();
42 
43 	if ((rd_reg32(&jrp->rregs->jrintstatus) & JRINT_ERR_HALT_MASK) !=
44 	    JRINT_ERR_HALT_COMPLETE || timeout == 0) {
45 		dev_err(dev, "failed to flush job ring %d\n", jrp->ridx);
46 		return -EIO;
47 	}
48 
49 	/* initiate reset */
50 	timeout = 100000;
51 	wr_reg32(&jrp->rregs->jrcommand, JRCR_RESET);
52 	while ((rd_reg32(&jrp->rregs->jrcommand) & JRCR_RESET) && --timeout)
53 		cpu_relax();
54 
55 	if (timeout == 0) {
56 		dev_err(dev, "failed to reset job ring %d\n", jrp->ridx);
57 		return -EIO;
58 	}
59 
60 	/* unmask interrupts */
61 	clrsetbits_32(&jrp->rregs->rconfig_lo, JRCFG_IMSK, 0);
62 
63 	return 0;
64 }
65 
66 /*
67  * Shutdown JobR independent of platform property code
68  */
69 static int caam_jr_shutdown(struct device *dev)
70 {
71 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
72 	dma_addr_t inpbusaddr, outbusaddr;
73 	int ret;
74 
75 	ret = caam_reset_hw_jr(dev);
76 
77 	tasklet_kill(&jrp->irqtask);
78 
79 	/* Release interrupt */
80 	free_irq(jrp->irq, dev);
81 
82 	/* Free rings */
83 	inpbusaddr = rd_reg64(&jrp->rregs->inpring_base);
84 	outbusaddr = rd_reg64(&jrp->rregs->outring_base);
85 	dma_free_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
86 			  jrp->inpring, inpbusaddr);
87 	dma_free_coherent(dev, sizeof(struct jr_outentry) * JOBR_DEPTH,
88 			  jrp->outring, outbusaddr);
89 	kfree(jrp->entinfo);
90 
91 	return ret;
92 }
93 
94 static int caam_jr_remove(struct platform_device *pdev)
95 {
96 	int ret;
97 	struct device *jrdev;
98 	struct caam_drv_private_jr *jrpriv;
99 
100 	jrdev = &pdev->dev;
101 	jrpriv = dev_get_drvdata(jrdev);
102 
103 	/*
104 	 * Return EBUSY if job ring already allocated.
105 	 */
106 	if (atomic_read(&jrpriv->tfm_count)) {
107 		dev_err(jrdev, "Device is busy\n");
108 		return -EBUSY;
109 	}
110 
111 	/* Remove the node from Physical JobR list maintained by driver */
112 	spin_lock(&driver_data.jr_alloc_lock);
113 	list_del(&jrpriv->list_node);
114 	spin_unlock(&driver_data.jr_alloc_lock);
115 
116 	/* Release ring */
117 	ret = caam_jr_shutdown(jrdev);
118 	if (ret)
119 		dev_err(jrdev, "Failed to shut down job ring\n");
120 	irq_dispose_mapping(jrpriv->irq);
121 
122 	return ret;
123 }
124 
125 /* Main per-ring interrupt handler */
126 static irqreturn_t caam_jr_interrupt(int irq, void *st_dev)
127 {
128 	struct device *dev = st_dev;
129 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
130 	u32 irqstate;
131 
132 	/*
133 	 * Check the output ring for ready responses, kick
134 	 * tasklet if jobs done.
135 	 */
136 	irqstate = rd_reg32(&jrp->rregs->jrintstatus);
137 	if (!irqstate)
138 		return IRQ_NONE;
139 
140 	/*
141 	 * If JobR error, we got more development work to do
142 	 * Flag a bug now, but we really need to shut down and
143 	 * restart the queue (and fix code).
144 	 */
145 	if (irqstate & JRINT_JR_ERROR) {
146 		dev_err(dev, "job ring error: irqstate: %08x\n", irqstate);
147 		BUG();
148 	}
149 
150 	/* mask valid interrupts */
151 	clrsetbits_32(&jrp->rregs->rconfig_lo, 0, JRCFG_IMSK);
152 
153 	/* Have valid interrupt at this point, just ACK and trigger */
154 	wr_reg32(&jrp->rregs->jrintstatus, irqstate);
155 
156 	preempt_disable();
157 	tasklet_schedule(&jrp->irqtask);
158 	preempt_enable();
159 
160 	return IRQ_HANDLED;
161 }
162 
163 /* Deferred service handler, run as interrupt-fired tasklet */
164 static void caam_jr_dequeue(unsigned long devarg)
165 {
166 	int hw_idx, sw_idx, i, head, tail;
167 	struct device *dev = (struct device *)devarg;
168 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
169 	void (*usercall)(struct device *dev, u32 *desc, u32 status, void *arg);
170 	u32 *userdesc, userstatus;
171 	void *userarg;
172 
173 	while (rd_reg32(&jrp->rregs->outring_used)) {
174 
175 		head = READ_ONCE(jrp->head);
176 
177 		spin_lock(&jrp->outlock);
178 
179 		sw_idx = tail = jrp->tail;
180 		hw_idx = jrp->out_ring_read_index;
181 
182 		for (i = 0; CIRC_CNT(head, tail + i, JOBR_DEPTH) >= 1; i++) {
183 			sw_idx = (tail + i) & (JOBR_DEPTH - 1);
184 
185 			if (jrp->outring[hw_idx].desc ==
186 			    caam_dma_to_cpu(jrp->entinfo[sw_idx].desc_addr_dma))
187 				break; /* found */
188 		}
189 		/* we should never fail to find a matching descriptor */
190 		BUG_ON(CIRC_CNT(head, tail + i, JOBR_DEPTH) <= 0);
191 
192 		/* Unmap just-run descriptor so we can post-process */
193 		dma_unmap_single(dev, jrp->outring[hw_idx].desc,
194 				 jrp->entinfo[sw_idx].desc_size,
195 				 DMA_TO_DEVICE);
196 
197 		/* mark completed, avoid matching on a recycled desc addr */
198 		jrp->entinfo[sw_idx].desc_addr_dma = 0;
199 
200 		/* Stash callback params for use outside of lock */
201 		usercall = jrp->entinfo[sw_idx].callbk;
202 		userarg = jrp->entinfo[sw_idx].cbkarg;
203 		userdesc = jrp->entinfo[sw_idx].desc_addr_virt;
204 		userstatus = caam32_to_cpu(jrp->outring[hw_idx].jrstatus);
205 
206 		/*
207 		 * Make sure all information from the job has been obtained
208 		 * before telling CAAM that the job has been removed from the
209 		 * output ring.
210 		 */
211 		mb();
212 
213 		/* set done */
214 		wr_reg32(&jrp->rregs->outring_rmvd, 1);
215 
216 		jrp->out_ring_read_index = (jrp->out_ring_read_index + 1) &
217 					   (JOBR_DEPTH - 1);
218 
219 		/*
220 		 * if this job completed out-of-order, do not increment
221 		 * the tail.  Otherwise, increment tail by 1 plus the
222 		 * number of subsequent jobs already completed out-of-order
223 		 */
224 		if (sw_idx == tail) {
225 			do {
226 				tail = (tail + 1) & (JOBR_DEPTH - 1);
227 			} while (CIRC_CNT(head, tail, JOBR_DEPTH) >= 1 &&
228 				 jrp->entinfo[tail].desc_addr_dma == 0);
229 
230 			jrp->tail = tail;
231 		}
232 
233 		spin_unlock(&jrp->outlock);
234 
235 		/* Finally, execute user's callback */
236 		usercall(dev, userdesc, userstatus, userarg);
237 	}
238 
239 	/* reenable / unmask IRQs */
240 	clrsetbits_32(&jrp->rregs->rconfig_lo, JRCFG_IMSK, 0);
241 }
242 
243 /**
244  * caam_jr_alloc() - Alloc a job ring for someone to use as needed.
245  *
246  * returns :  pointer to the newly allocated physical
247  *	      JobR dev can be written to if successful.
248  **/
249 struct device *caam_jr_alloc(void)
250 {
251 	struct caam_drv_private_jr *jrpriv, *min_jrpriv = NULL;
252 	struct device *dev = ERR_PTR(-ENODEV);
253 	int min_tfm_cnt	= INT_MAX;
254 	int tfm_cnt;
255 
256 	spin_lock(&driver_data.jr_alloc_lock);
257 
258 	if (list_empty(&driver_data.jr_list)) {
259 		spin_unlock(&driver_data.jr_alloc_lock);
260 		return ERR_PTR(-ENODEV);
261 	}
262 
263 	list_for_each_entry(jrpriv, &driver_data.jr_list, list_node) {
264 		tfm_cnt = atomic_read(&jrpriv->tfm_count);
265 		if (tfm_cnt < min_tfm_cnt) {
266 			min_tfm_cnt = tfm_cnt;
267 			min_jrpriv = jrpriv;
268 		}
269 		if (!min_tfm_cnt)
270 			break;
271 	}
272 
273 	if (min_jrpriv) {
274 		atomic_inc(&min_jrpriv->tfm_count);
275 		dev = min_jrpriv->dev;
276 	}
277 	spin_unlock(&driver_data.jr_alloc_lock);
278 
279 	return dev;
280 }
281 EXPORT_SYMBOL(caam_jr_alloc);
282 
283 /**
284  * caam_jr_free() - Free the Job Ring
285  * @rdev     - points to the dev that identifies the Job ring to
286  *             be released.
287  **/
288 void caam_jr_free(struct device *rdev)
289 {
290 	struct caam_drv_private_jr *jrpriv = dev_get_drvdata(rdev);
291 
292 	atomic_dec(&jrpriv->tfm_count);
293 }
294 EXPORT_SYMBOL(caam_jr_free);
295 
296 /**
297  * caam_jr_enqueue() - Enqueue a job descriptor head. Returns 0 if OK,
298  * -EBUSY if the queue is full, -EIO if it cannot map the caller's
299  * descriptor.
300  * @dev:  device of the job ring to be used. This device should have
301  *        been assigned prior by caam_jr_register().
302  * @desc: points to a job descriptor that execute our request. All
303  *        descriptors (and all referenced data) must be in a DMAable
304  *        region, and all data references must be physical addresses
305  *        accessible to CAAM (i.e. within a PAMU window granted
306  *        to it).
307  * @cbk:  pointer to a callback function to be invoked upon completion
308  *        of this request. This has the form:
309  *        callback(struct device *dev, u32 *desc, u32 stat, void *arg)
310  *        where:
311  *        @dev:    contains the job ring device that processed this
312  *                 response.
313  *        @desc:   descriptor that initiated the request, same as
314  *                 "desc" being argued to caam_jr_enqueue().
315  *        @status: untranslated status received from CAAM. See the
316  *                 reference manual for a detailed description of
317  *                 error meaning, or see the JRSTA definitions in the
318  *                 register header file
319  *        @areq:   optional pointer to an argument passed with the
320  *                 original request
321  * @areq: optional pointer to a user argument for use at callback
322  *        time.
323  **/
324 int caam_jr_enqueue(struct device *dev, u32 *desc,
325 		    void (*cbk)(struct device *dev, u32 *desc,
326 				u32 status, void *areq),
327 		    void *areq)
328 {
329 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
330 	struct caam_jrentry_info *head_entry;
331 	int head, tail, desc_size;
332 	dma_addr_t desc_dma;
333 
334 	desc_size = (caam32_to_cpu(*desc) & HDR_JD_LENGTH_MASK) * sizeof(u32);
335 	desc_dma = dma_map_single(dev, desc, desc_size, DMA_TO_DEVICE);
336 	if (dma_mapping_error(dev, desc_dma)) {
337 		dev_err(dev, "caam_jr_enqueue(): can't map jobdesc\n");
338 		return -EIO;
339 	}
340 
341 	spin_lock_bh(&jrp->inplock);
342 
343 	head = jrp->head;
344 	tail = READ_ONCE(jrp->tail);
345 
346 	if (!rd_reg32(&jrp->rregs->inpring_avail) ||
347 	    CIRC_SPACE(head, tail, JOBR_DEPTH) <= 0) {
348 		spin_unlock_bh(&jrp->inplock);
349 		dma_unmap_single(dev, desc_dma, desc_size, DMA_TO_DEVICE);
350 		return -EBUSY;
351 	}
352 
353 	head_entry = &jrp->entinfo[head];
354 	head_entry->desc_addr_virt = desc;
355 	head_entry->desc_size = desc_size;
356 	head_entry->callbk = (void *)cbk;
357 	head_entry->cbkarg = areq;
358 	head_entry->desc_addr_dma = desc_dma;
359 
360 	jrp->inpring[jrp->inp_ring_write_index] = cpu_to_caam_dma(desc_dma);
361 
362 	/*
363 	 * Guarantee that the descriptor's DMA address has been written to
364 	 * the next slot in the ring before the write index is updated, since
365 	 * other cores may update this index independently.
366 	 */
367 	smp_wmb();
368 
369 	jrp->inp_ring_write_index = (jrp->inp_ring_write_index + 1) &
370 				    (JOBR_DEPTH - 1);
371 	jrp->head = (head + 1) & (JOBR_DEPTH - 1);
372 
373 	/*
374 	 * Ensure that all job information has been written before
375 	 * notifying CAAM that a new job was added to the input ring.
376 	 */
377 	wmb();
378 
379 	wr_reg32(&jrp->rregs->inpring_jobadd, 1);
380 
381 	spin_unlock_bh(&jrp->inplock);
382 
383 	return 0;
384 }
385 EXPORT_SYMBOL(caam_jr_enqueue);
386 
387 /*
388  * Init JobR independent of platform property detection
389  */
390 static int caam_jr_init(struct device *dev)
391 {
392 	struct caam_drv_private_jr *jrp;
393 	dma_addr_t inpbusaddr, outbusaddr;
394 	int i, error;
395 
396 	jrp = dev_get_drvdata(dev);
397 
398 	tasklet_init(&jrp->irqtask, caam_jr_dequeue, (unsigned long)dev);
399 
400 	/* Connect job ring interrupt handler. */
401 	error = request_irq(jrp->irq, caam_jr_interrupt, IRQF_SHARED,
402 			    dev_name(dev), dev);
403 	if (error) {
404 		dev_err(dev, "can't connect JobR %d interrupt (%d)\n",
405 			jrp->ridx, jrp->irq);
406 		goto out_kill_deq;
407 	}
408 
409 	error = caam_reset_hw_jr(dev);
410 	if (error)
411 		goto out_free_irq;
412 
413 	error = -ENOMEM;
414 	jrp->inpring = dma_alloc_coherent(dev, sizeof(*jrp->inpring) *
415 					  JOBR_DEPTH, &inpbusaddr, GFP_KERNEL);
416 	if (!jrp->inpring)
417 		goto out_free_irq;
418 
419 	jrp->outring = dma_alloc_coherent(dev, sizeof(*jrp->outring) *
420 					  JOBR_DEPTH, &outbusaddr, GFP_KERNEL);
421 	if (!jrp->outring)
422 		goto out_free_inpring;
423 
424 	jrp->entinfo = kcalloc(JOBR_DEPTH, sizeof(*jrp->entinfo), GFP_KERNEL);
425 	if (!jrp->entinfo)
426 		goto out_free_outring;
427 
428 	for (i = 0; i < JOBR_DEPTH; i++)
429 		jrp->entinfo[i].desc_addr_dma = !0;
430 
431 	/* Setup rings */
432 	jrp->inp_ring_write_index = 0;
433 	jrp->out_ring_read_index = 0;
434 	jrp->head = 0;
435 	jrp->tail = 0;
436 
437 	wr_reg64(&jrp->rregs->inpring_base, inpbusaddr);
438 	wr_reg64(&jrp->rregs->outring_base, outbusaddr);
439 	wr_reg32(&jrp->rregs->inpring_size, JOBR_DEPTH);
440 	wr_reg32(&jrp->rregs->outring_size, JOBR_DEPTH);
441 
442 	jrp->ringsize = JOBR_DEPTH;
443 
444 	spin_lock_init(&jrp->inplock);
445 	spin_lock_init(&jrp->outlock);
446 
447 	/* Select interrupt coalescing parameters */
448 	clrsetbits_32(&jrp->rregs->rconfig_lo, 0, JOBR_INTC |
449 		      (JOBR_INTC_COUNT_THLD << JRCFG_ICDCT_SHIFT) |
450 		      (JOBR_INTC_TIME_THLD << JRCFG_ICTT_SHIFT));
451 
452 	return 0;
453 
454 out_free_outring:
455 	dma_free_coherent(dev, sizeof(struct jr_outentry) * JOBR_DEPTH,
456 			  jrp->outring, outbusaddr);
457 out_free_inpring:
458 	dma_free_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
459 			  jrp->inpring, inpbusaddr);
460 	dev_err(dev, "can't allocate job rings for %d\n", jrp->ridx);
461 out_free_irq:
462 	free_irq(jrp->irq, dev);
463 out_kill_deq:
464 	tasklet_kill(&jrp->irqtask);
465 	return error;
466 }
467 
468 
469 /*
470  * Probe routine for each detected JobR subsystem.
471  */
472 static int caam_jr_probe(struct platform_device *pdev)
473 {
474 	struct device *jrdev;
475 	struct device_node *nprop;
476 	struct caam_job_ring __iomem *ctrl;
477 	struct caam_drv_private_jr *jrpriv;
478 	static int total_jobrs;
479 	int error;
480 
481 	jrdev = &pdev->dev;
482 	jrpriv = devm_kmalloc(jrdev, sizeof(*jrpriv), GFP_KERNEL);
483 	if (!jrpriv)
484 		return -ENOMEM;
485 
486 	dev_set_drvdata(jrdev, jrpriv);
487 
488 	/* save ring identity relative to detection */
489 	jrpriv->ridx = total_jobrs++;
490 
491 	nprop = pdev->dev.of_node;
492 	/* Get configuration properties from device tree */
493 	/* First, get register page */
494 	ctrl = of_iomap(nprop, 0);
495 	if (!ctrl) {
496 		dev_err(jrdev, "of_iomap() failed\n");
497 		return -ENOMEM;
498 	}
499 
500 	jrpriv->rregs = (struct caam_job_ring __iomem __force *)ctrl;
501 
502 	if (sizeof(dma_addr_t) == sizeof(u64)) {
503 		if (caam_dpaa2)
504 			error = dma_set_mask_and_coherent(jrdev,
505 							  DMA_BIT_MASK(49));
506 		else if (of_device_is_compatible(nprop,
507 						 "fsl,sec-v5.0-job-ring"))
508 			error = dma_set_mask_and_coherent(jrdev,
509 							  DMA_BIT_MASK(40));
510 		else
511 			error = dma_set_mask_and_coherent(jrdev,
512 							  DMA_BIT_MASK(36));
513 	} else {
514 		error = dma_set_mask_and_coherent(jrdev, DMA_BIT_MASK(32));
515 	}
516 	if (error) {
517 		dev_err(jrdev, "dma_set_mask_and_coherent failed (%d)\n",
518 			error);
519 		iounmap(ctrl);
520 		return error;
521 	}
522 
523 	/* Identify the interrupt */
524 	jrpriv->irq = irq_of_parse_and_map(nprop, 0);
525 
526 	/* Now do the platform independent part */
527 	error = caam_jr_init(jrdev); /* now turn on hardware */
528 	if (error) {
529 		irq_dispose_mapping(jrpriv->irq);
530 		iounmap(ctrl);
531 		return error;
532 	}
533 
534 	jrpriv->dev = jrdev;
535 	spin_lock(&driver_data.jr_alloc_lock);
536 	list_add_tail(&jrpriv->list_node, &driver_data.jr_list);
537 	spin_unlock(&driver_data.jr_alloc_lock);
538 
539 	atomic_set(&jrpriv->tfm_count, 0);
540 
541 	return 0;
542 }
543 
544 static const struct of_device_id caam_jr_match[] = {
545 	{
546 		.compatible = "fsl,sec-v4.0-job-ring",
547 	},
548 	{
549 		.compatible = "fsl,sec4.0-job-ring",
550 	},
551 	{},
552 };
553 MODULE_DEVICE_TABLE(of, caam_jr_match);
554 
555 static struct platform_driver caam_jr_driver = {
556 	.driver = {
557 		.name = "caam_jr",
558 		.of_match_table = caam_jr_match,
559 	},
560 	.probe       = caam_jr_probe,
561 	.remove      = caam_jr_remove,
562 };
563 
564 static int __init jr_driver_init(void)
565 {
566 	spin_lock_init(&driver_data.jr_alloc_lock);
567 	INIT_LIST_HEAD(&driver_data.jr_list);
568 	return platform_driver_register(&caam_jr_driver);
569 }
570 
571 static void __exit jr_driver_exit(void)
572 {
573 	platform_driver_unregister(&caam_jr_driver);
574 }
575 
576 module_init(jr_driver_init);
577 module_exit(jr_driver_exit);
578 
579 MODULE_LICENSE("GPL");
580 MODULE_DESCRIPTION("FSL CAAM JR request backend");
581 MODULE_AUTHOR("Freescale Semiconductor - NMG/STC");
582