xref: /openbmc/linux/drivers/crypto/caam/jr.c (revision 6dfcd296)
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 "regs.h"
13 #include "jr.h"
14 #include "desc.h"
15 #include "intern.h"
16 
17 struct jr_driver_data {
18 	/* List of Physical JobR's with the Driver */
19 	struct list_head	jr_list;
20 	spinlock_t		jr_alloc_lock;	/* jr_list lock */
21 } ____cacheline_aligned;
22 
23 static struct jr_driver_data driver_data;
24 
25 static int caam_reset_hw_jr(struct device *dev)
26 {
27 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
28 	unsigned int timeout = 100000;
29 
30 	/*
31 	 * mask interrupts since we are going to poll
32 	 * for reset completion status
33 	 */
34 	clrsetbits_32(&jrp->rregs->rconfig_lo, 0, JRCFG_IMSK);
35 
36 	/* initiate flush (required prior to reset) */
37 	wr_reg32(&jrp->rregs->jrcommand, JRCR_RESET);
38 	while (((rd_reg32(&jrp->rregs->jrintstatus) & JRINT_ERR_HALT_MASK) ==
39 		JRINT_ERR_HALT_INPROGRESS) && --timeout)
40 		cpu_relax();
41 
42 	if ((rd_reg32(&jrp->rregs->jrintstatus) & JRINT_ERR_HALT_MASK) !=
43 	    JRINT_ERR_HALT_COMPLETE || timeout == 0) {
44 		dev_err(dev, "failed to flush job ring %d\n", jrp->ridx);
45 		return -EIO;
46 	}
47 
48 	/* initiate reset */
49 	timeout = 100000;
50 	wr_reg32(&jrp->rregs->jrcommand, JRCR_RESET);
51 	while ((rd_reg32(&jrp->rregs->jrcommand) & JRCR_RESET) && --timeout)
52 		cpu_relax();
53 
54 	if (timeout == 0) {
55 		dev_err(dev, "failed to reset job ring %d\n", jrp->ridx);
56 		return -EIO;
57 	}
58 
59 	/* unmask interrupts */
60 	clrsetbits_32(&jrp->rregs->rconfig_lo, JRCFG_IMSK, 0);
61 
62 	return 0;
63 }
64 
65 /*
66  * Shutdown JobR independent of platform property code
67  */
68 static int caam_jr_shutdown(struct device *dev)
69 {
70 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
71 	dma_addr_t inpbusaddr, outbusaddr;
72 	int ret;
73 
74 	ret = caam_reset_hw_jr(dev);
75 
76 	/* Release interrupt */
77 	free_irq(jrp->irq, dev);
78 
79 	/* Free rings */
80 	inpbusaddr = rd_reg64(&jrp->rregs->inpring_base);
81 	outbusaddr = rd_reg64(&jrp->rregs->outring_base);
82 	dma_free_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
83 			  jrp->inpring, inpbusaddr);
84 	dma_free_coherent(dev, sizeof(struct jr_outentry) * JOBR_DEPTH,
85 			  jrp->outring, outbusaddr);
86 	kfree(jrp->entinfo);
87 
88 	return ret;
89 }
90 
91 static int caam_jr_remove(struct platform_device *pdev)
92 {
93 	int ret;
94 	struct device *jrdev;
95 	struct caam_drv_private_jr *jrpriv;
96 
97 	jrdev = &pdev->dev;
98 	jrpriv = dev_get_drvdata(jrdev);
99 
100 	/*
101 	 * Return EBUSY if job ring already allocated.
102 	 */
103 	if (atomic_read(&jrpriv->tfm_count)) {
104 		dev_err(jrdev, "Device is busy\n");
105 		return -EBUSY;
106 	}
107 
108 	/* Remove the node from Physical JobR list maintained by driver */
109 	spin_lock(&driver_data.jr_alloc_lock);
110 	list_del(&jrpriv->list_node);
111 	spin_unlock(&driver_data.jr_alloc_lock);
112 
113 	/* Release ring */
114 	ret = caam_jr_shutdown(jrdev);
115 	if (ret)
116 		dev_err(jrdev, "Failed to shut down job ring\n");
117 	irq_dispose_mapping(jrpriv->irq);
118 
119 	return ret;
120 }
121 
122 /* Main per-ring interrupt handler */
123 static irqreturn_t caam_jr_interrupt(int irq, void *st_dev)
124 {
125 	struct device *dev = st_dev;
126 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
127 	u32 irqstate;
128 
129 	/*
130 	 * Check the output ring for ready responses, kick
131 	 * the threaded irq if jobs done.
132 	 */
133 	irqstate = rd_reg32(&jrp->rregs->jrintstatus);
134 	if (!irqstate)
135 		return IRQ_NONE;
136 
137 	/*
138 	 * If JobR error, we got more development work to do
139 	 * Flag a bug now, but we really need to shut down and
140 	 * restart the queue (and fix code).
141 	 */
142 	if (irqstate & JRINT_JR_ERROR) {
143 		dev_err(dev, "job ring error: irqstate: %08x\n", irqstate);
144 		BUG();
145 	}
146 
147 	/* mask valid interrupts */
148 	clrsetbits_32(&jrp->rregs->rconfig_lo, 0, JRCFG_IMSK);
149 
150 	/* Have valid interrupt at this point, just ACK and trigger */
151 	wr_reg32(&jrp->rregs->jrintstatus, irqstate);
152 
153 	return IRQ_WAKE_THREAD;
154 }
155 
156 static irqreturn_t caam_jr_threadirq(int irq, void *st_dev)
157 {
158 	int hw_idx, sw_idx, i, head, tail;
159 	struct device *dev = st_dev;
160 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
161 	void (*usercall)(struct device *dev, u32 *desc, u32 status, void *arg);
162 	u32 *userdesc, userstatus;
163 	void *userarg;
164 
165 	while (rd_reg32(&jrp->rregs->outring_used)) {
166 
167 		head = ACCESS_ONCE(jrp->head);
168 
169 		spin_lock(&jrp->outlock);
170 
171 		sw_idx = tail = jrp->tail;
172 		hw_idx = jrp->out_ring_read_index;
173 
174 		for (i = 0; CIRC_CNT(head, tail + i, JOBR_DEPTH) >= 1; i++) {
175 			sw_idx = (tail + i) & (JOBR_DEPTH - 1);
176 
177 			if (jrp->outring[hw_idx].desc ==
178 			    caam_dma_to_cpu(jrp->entinfo[sw_idx].desc_addr_dma))
179 				break; /* found */
180 		}
181 		/* we should never fail to find a matching descriptor */
182 		BUG_ON(CIRC_CNT(head, tail + i, JOBR_DEPTH) <= 0);
183 
184 		/* Unmap just-run descriptor so we can post-process */
185 		dma_unmap_single(dev, jrp->outring[hw_idx].desc,
186 				 jrp->entinfo[sw_idx].desc_size,
187 				 DMA_TO_DEVICE);
188 
189 		/* mark completed, avoid matching on a recycled desc addr */
190 		jrp->entinfo[sw_idx].desc_addr_dma = 0;
191 
192 		/* Stash callback params for use outside of lock */
193 		usercall = jrp->entinfo[sw_idx].callbk;
194 		userarg = jrp->entinfo[sw_idx].cbkarg;
195 		userdesc = jrp->entinfo[sw_idx].desc_addr_virt;
196 		userstatus = caam32_to_cpu(jrp->outring[hw_idx].jrstatus);
197 
198 		/*
199 		 * Make sure all information from the job has been obtained
200 		 * before telling CAAM that the job has been removed from the
201 		 * output ring.
202 		 */
203 		mb();
204 
205 		/* set done */
206 		wr_reg32(&jrp->rregs->outring_rmvd, 1);
207 
208 		jrp->out_ring_read_index = (jrp->out_ring_read_index + 1) &
209 					   (JOBR_DEPTH - 1);
210 
211 		/*
212 		 * if this job completed out-of-order, do not increment
213 		 * the tail.  Otherwise, increment tail by 1 plus the
214 		 * number of subsequent jobs already completed out-of-order
215 		 */
216 		if (sw_idx == tail) {
217 			do {
218 				tail = (tail + 1) & (JOBR_DEPTH - 1);
219 			} while (CIRC_CNT(head, tail, JOBR_DEPTH) >= 1 &&
220 				 jrp->entinfo[tail].desc_addr_dma == 0);
221 
222 			jrp->tail = tail;
223 		}
224 
225 		spin_unlock(&jrp->outlock);
226 
227 		/* Finally, execute user's callback */
228 		usercall(dev, userdesc, userstatus, userarg);
229 	}
230 
231 	/* reenable / unmask IRQs */
232 	clrsetbits_32(&jrp->rregs->rconfig_lo, JRCFG_IMSK, 0);
233 
234 	return IRQ_HANDLED;
235 }
236 
237 /**
238  * caam_jr_alloc() - Alloc a job ring for someone to use as needed.
239  *
240  * returns :  pointer to the newly allocated physical
241  *	      JobR dev can be written to if successful.
242  **/
243 struct device *caam_jr_alloc(void)
244 {
245 	struct caam_drv_private_jr *jrpriv, *min_jrpriv = NULL;
246 	struct device *dev = ERR_PTR(-ENODEV);
247 	int min_tfm_cnt	= INT_MAX;
248 	int tfm_cnt;
249 
250 	spin_lock(&driver_data.jr_alloc_lock);
251 
252 	if (list_empty(&driver_data.jr_list)) {
253 		spin_unlock(&driver_data.jr_alloc_lock);
254 		return ERR_PTR(-ENODEV);
255 	}
256 
257 	list_for_each_entry(jrpriv, &driver_data.jr_list, list_node) {
258 		tfm_cnt = atomic_read(&jrpriv->tfm_count);
259 		if (tfm_cnt < min_tfm_cnt) {
260 			min_tfm_cnt = tfm_cnt;
261 			min_jrpriv = jrpriv;
262 		}
263 		if (!min_tfm_cnt)
264 			break;
265 	}
266 
267 	if (min_jrpriv) {
268 		atomic_inc(&min_jrpriv->tfm_count);
269 		dev = min_jrpriv->dev;
270 	}
271 	spin_unlock(&driver_data.jr_alloc_lock);
272 
273 	return dev;
274 }
275 EXPORT_SYMBOL(caam_jr_alloc);
276 
277 /**
278  * caam_jr_free() - Free the Job Ring
279  * @rdev     - points to the dev that identifies the Job ring to
280  *             be released.
281  **/
282 void caam_jr_free(struct device *rdev)
283 {
284 	struct caam_drv_private_jr *jrpriv = dev_get_drvdata(rdev);
285 
286 	atomic_dec(&jrpriv->tfm_count);
287 }
288 EXPORT_SYMBOL(caam_jr_free);
289 
290 /**
291  * caam_jr_enqueue() - Enqueue a job descriptor head. Returns 0 if OK,
292  * -EBUSY if the queue is full, -EIO if it cannot map the caller's
293  * descriptor.
294  * @dev:  device of the job ring to be used. This device should have
295  *        been assigned prior by caam_jr_register().
296  * @desc: points to a job descriptor that execute our request. All
297  *        descriptors (and all referenced data) must be in a DMAable
298  *        region, and all data references must be physical addresses
299  *        accessible to CAAM (i.e. within a PAMU window granted
300  *        to it).
301  * @cbk:  pointer to a callback function to be invoked upon completion
302  *        of this request. This has the form:
303  *        callback(struct device *dev, u32 *desc, u32 stat, void *arg)
304  *        where:
305  *        @dev:    contains the job ring device that processed this
306  *                 response.
307  *        @desc:   descriptor that initiated the request, same as
308  *                 "desc" being argued to caam_jr_enqueue().
309  *        @status: untranslated status received from CAAM. See the
310  *                 reference manual for a detailed description of
311  *                 error meaning, or see the JRSTA definitions in the
312  *                 register header file
313  *        @areq:   optional pointer to an argument passed with the
314  *                 original request
315  * @areq: optional pointer to a user argument for use at callback
316  *        time.
317  **/
318 int caam_jr_enqueue(struct device *dev, u32 *desc,
319 		    void (*cbk)(struct device *dev, u32 *desc,
320 				u32 status, void *areq),
321 		    void *areq)
322 {
323 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
324 	struct caam_jrentry_info *head_entry;
325 	int head, tail, desc_size;
326 	dma_addr_t desc_dma;
327 
328 	desc_size = (caam32_to_cpu(*desc) & HDR_JD_LENGTH_MASK) * sizeof(u32);
329 	desc_dma = dma_map_single(dev, desc, desc_size, DMA_TO_DEVICE);
330 	if (dma_mapping_error(dev, desc_dma)) {
331 		dev_err(dev, "caam_jr_enqueue(): can't map jobdesc\n");
332 		return -EIO;
333 	}
334 
335 	spin_lock_bh(&jrp->inplock);
336 
337 	head = jrp->head;
338 	tail = ACCESS_ONCE(jrp->tail);
339 
340 	if (!rd_reg32(&jrp->rregs->inpring_avail) ||
341 	    CIRC_SPACE(head, tail, JOBR_DEPTH) <= 0) {
342 		spin_unlock_bh(&jrp->inplock);
343 		dma_unmap_single(dev, desc_dma, desc_size, DMA_TO_DEVICE);
344 		return -EBUSY;
345 	}
346 
347 	head_entry = &jrp->entinfo[head];
348 	head_entry->desc_addr_virt = desc;
349 	head_entry->desc_size = desc_size;
350 	head_entry->callbk = (void *)cbk;
351 	head_entry->cbkarg = areq;
352 	head_entry->desc_addr_dma = desc_dma;
353 
354 	jrp->inpring[jrp->inp_ring_write_index] = cpu_to_caam_dma(desc_dma);
355 
356 	/*
357 	 * Guarantee that the descriptor's DMA address has been written to
358 	 * the next slot in the ring before the write index is updated, since
359 	 * other cores may update this index independently.
360 	 */
361 	smp_wmb();
362 
363 	jrp->inp_ring_write_index = (jrp->inp_ring_write_index + 1) &
364 				    (JOBR_DEPTH - 1);
365 	jrp->head = (head + 1) & (JOBR_DEPTH - 1);
366 
367 	/*
368 	 * Ensure that all job information has been written before
369 	 * notifying CAAM that a new job was added to the input ring.
370 	 */
371 	wmb();
372 
373 	wr_reg32(&jrp->rregs->inpring_jobadd, 1);
374 
375 	spin_unlock_bh(&jrp->inplock);
376 
377 	return 0;
378 }
379 EXPORT_SYMBOL(caam_jr_enqueue);
380 
381 /*
382  * Init JobR independent of platform property detection
383  */
384 static int caam_jr_init(struct device *dev)
385 {
386 	struct caam_drv_private_jr *jrp;
387 	dma_addr_t inpbusaddr, outbusaddr;
388 	int i, error;
389 
390 	jrp = dev_get_drvdata(dev);
391 
392 	/* Connect job ring interrupt handler. */
393 	error = request_threaded_irq(jrp->irq, caam_jr_interrupt,
394 				     caam_jr_threadirq, IRQF_SHARED,
395 				     dev_name(dev), dev);
396 	if (error) {
397 		dev_err(dev, "can't connect JobR %d interrupt (%d)\n",
398 			jrp->ridx, jrp->irq);
399 		goto out_kill_deq;
400 	}
401 
402 	error = caam_reset_hw_jr(dev);
403 	if (error)
404 		goto out_free_irq;
405 
406 	error = -ENOMEM;
407 	jrp->inpring = dma_alloc_coherent(dev, sizeof(*jrp->inpring) *
408 					  JOBR_DEPTH, &inpbusaddr, GFP_KERNEL);
409 	if (!jrp->inpring)
410 		goto out_free_irq;
411 
412 	jrp->outring = dma_alloc_coherent(dev, sizeof(*jrp->outring) *
413 					  JOBR_DEPTH, &outbusaddr, GFP_KERNEL);
414 	if (!jrp->outring)
415 		goto out_free_inpring;
416 
417 	jrp->entinfo = kcalloc(JOBR_DEPTH, sizeof(*jrp->entinfo), GFP_KERNEL);
418 	if (!jrp->entinfo)
419 		goto out_free_outring;
420 
421 	for (i = 0; i < JOBR_DEPTH; i++)
422 		jrp->entinfo[i].desc_addr_dma = !0;
423 
424 	/* Setup rings */
425 	jrp->inp_ring_write_index = 0;
426 	jrp->out_ring_read_index = 0;
427 	jrp->head = 0;
428 	jrp->tail = 0;
429 
430 	wr_reg64(&jrp->rregs->inpring_base, inpbusaddr);
431 	wr_reg64(&jrp->rregs->outring_base, outbusaddr);
432 	wr_reg32(&jrp->rregs->inpring_size, JOBR_DEPTH);
433 	wr_reg32(&jrp->rregs->outring_size, JOBR_DEPTH);
434 
435 	jrp->ringsize = JOBR_DEPTH;
436 
437 	spin_lock_init(&jrp->inplock);
438 	spin_lock_init(&jrp->outlock);
439 
440 	/* Select interrupt coalescing parameters */
441 	clrsetbits_32(&jrp->rregs->rconfig_lo, 0, JOBR_INTC |
442 		      (JOBR_INTC_COUNT_THLD << JRCFG_ICDCT_SHIFT) |
443 		      (JOBR_INTC_TIME_THLD << JRCFG_ICTT_SHIFT));
444 
445 	return 0;
446 
447 out_free_outring:
448 	dma_free_coherent(dev, sizeof(struct jr_outentry) * JOBR_DEPTH,
449 			  jrp->outring, outbusaddr);
450 out_free_inpring:
451 	dma_free_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
452 			  jrp->inpring, inpbusaddr);
453 	dev_err(dev, "can't allocate job rings for %d\n", jrp->ridx);
454 out_free_irq:
455 	free_irq(jrp->irq, dev);
456 out_kill_deq:
457 	return error;
458 }
459 
460 
461 /*
462  * Probe routine for each detected JobR subsystem.
463  */
464 static int caam_jr_probe(struct platform_device *pdev)
465 {
466 	struct device *jrdev;
467 	struct device_node *nprop;
468 	struct caam_job_ring __iomem *ctrl;
469 	struct caam_drv_private_jr *jrpriv;
470 	static int total_jobrs;
471 	int error;
472 
473 	jrdev = &pdev->dev;
474 	jrpriv = devm_kmalloc(jrdev, sizeof(*jrpriv), GFP_KERNEL);
475 	if (!jrpriv)
476 		return -ENOMEM;
477 
478 	dev_set_drvdata(jrdev, jrpriv);
479 
480 	/* save ring identity relative to detection */
481 	jrpriv->ridx = total_jobrs++;
482 
483 	nprop = pdev->dev.of_node;
484 	/* Get configuration properties from device tree */
485 	/* First, get register page */
486 	ctrl = of_iomap(nprop, 0);
487 	if (!ctrl) {
488 		dev_err(jrdev, "of_iomap() failed\n");
489 		return -ENOMEM;
490 	}
491 
492 	jrpriv->rregs = (struct caam_job_ring __force *)ctrl;
493 
494 	if (sizeof(dma_addr_t) == sizeof(u64))
495 		if (of_device_is_compatible(nprop, "fsl,sec-v5.0-job-ring"))
496 			dma_set_mask_and_coherent(jrdev, DMA_BIT_MASK(40));
497 		else
498 			dma_set_mask_and_coherent(jrdev, DMA_BIT_MASK(36));
499 	else
500 		dma_set_mask_and_coherent(jrdev, DMA_BIT_MASK(32));
501 
502 	/* Identify the interrupt */
503 	jrpriv->irq = irq_of_parse_and_map(nprop, 0);
504 
505 	/* Now do the platform independent part */
506 	error = caam_jr_init(jrdev); /* now turn on hardware */
507 	if (error) {
508 		irq_dispose_mapping(jrpriv->irq);
509 		iounmap(ctrl);
510 		return error;
511 	}
512 
513 	jrpriv->dev = jrdev;
514 	spin_lock(&driver_data.jr_alloc_lock);
515 	list_add_tail(&jrpriv->list_node, &driver_data.jr_list);
516 	spin_unlock(&driver_data.jr_alloc_lock);
517 
518 	atomic_set(&jrpriv->tfm_count, 0);
519 
520 	return 0;
521 }
522 
523 static struct of_device_id caam_jr_match[] = {
524 	{
525 		.compatible = "fsl,sec-v4.0-job-ring",
526 	},
527 	{
528 		.compatible = "fsl,sec4.0-job-ring",
529 	},
530 	{},
531 };
532 MODULE_DEVICE_TABLE(of, caam_jr_match);
533 
534 static struct platform_driver caam_jr_driver = {
535 	.driver = {
536 		.name = "caam_jr",
537 		.of_match_table = caam_jr_match,
538 	},
539 	.probe       = caam_jr_probe,
540 	.remove      = caam_jr_remove,
541 };
542 
543 static int __init jr_driver_init(void)
544 {
545 	spin_lock_init(&driver_data.jr_alloc_lock);
546 	INIT_LIST_HEAD(&driver_data.jr_list);
547 	return platform_driver_register(&caam_jr_driver);
548 }
549 
550 static void __exit jr_driver_exit(void)
551 {
552 	platform_driver_unregister(&caam_jr_driver);
553 }
554 
555 module_init(jr_driver_init);
556 module_exit(jr_driver_exit);
557 
558 MODULE_LICENSE("GPL");
559 MODULE_DESCRIPTION("FSL CAAM JR request backend");
560 MODULE_AUTHOR("Freescale Semiconductor - NMG/STC");
561