xref: /openbmc/linux/drivers/crypto/caam/jr.c (revision 455f9726)
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 	setbits32(&jrp->rregs->rconfig_lo, 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 	clrbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);
61 
62 	return 0;
63 }
64 
65 /*
66  * Shutdown JobR independent of platform property code
67  */
68 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 	tasklet_kill(&jrp->irqtask);
77 
78 	/* Release interrupt */
79 	free_irq(jrp->irq, dev);
80 
81 	/* Free rings */
82 	inpbusaddr = rd_reg64(&jrp->rregs->inpring_base);
83 	outbusaddr = rd_reg64(&jrp->rregs->outring_base);
84 	dma_free_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
85 			  jrp->inpring, inpbusaddr);
86 	dma_free_coherent(dev, sizeof(struct jr_outentry) * JOBR_DEPTH,
87 			  jrp->outring, outbusaddr);
88 	kfree(jrp->entinfo);
89 
90 	return ret;
91 }
92 
93 static int caam_jr_remove(struct platform_device *pdev)
94 {
95 	int ret;
96 	struct device *jrdev;
97 	struct caam_drv_private_jr *jrpriv;
98 
99 	jrdev = &pdev->dev;
100 	jrpriv = dev_get_drvdata(jrdev);
101 
102 	/*
103 	 * Return EBUSY if job ring already allocated.
104 	 */
105 	if (atomic_read(&jrpriv->tfm_count)) {
106 		dev_err(jrdev, "Device is busy\n");
107 		return -EBUSY;
108 	}
109 
110 	/* Remove the node from Physical JobR list maintained by driver */
111 	spin_lock(&driver_data.jr_alloc_lock);
112 	list_del(&jrpriv->list_node);
113 	spin_unlock(&driver_data.jr_alloc_lock);
114 
115 	/* Release ring */
116 	ret = caam_jr_shutdown(jrdev);
117 	if (ret)
118 		dev_err(jrdev, "Failed to shut down job ring\n");
119 	irq_dispose_mapping(jrpriv->irq);
120 
121 	return ret;
122 }
123 
124 /* Main per-ring interrupt handler */
125 static irqreturn_t caam_jr_interrupt(int irq, void *st_dev)
126 {
127 	struct device *dev = st_dev;
128 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
129 	u32 irqstate;
130 
131 	/*
132 	 * Check the output ring for ready responses, kick
133 	 * tasklet if jobs done.
134 	 */
135 	irqstate = rd_reg32(&jrp->rregs->jrintstatus);
136 	if (!irqstate)
137 		return IRQ_NONE;
138 
139 	/*
140 	 * If JobR error, we got more development work to do
141 	 * Flag a bug now, but we really need to shut down and
142 	 * restart the queue (and fix code).
143 	 */
144 	if (irqstate & JRINT_JR_ERROR) {
145 		dev_err(dev, "job ring error: irqstate: %08x\n", irqstate);
146 		BUG();
147 	}
148 
149 	/* mask valid interrupts */
150 	setbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);
151 
152 	/* Have valid interrupt at this point, just ACK and trigger */
153 	wr_reg32(&jrp->rregs->jrintstatus, irqstate);
154 
155 	preempt_disable();
156 	tasklet_schedule(&jrp->irqtask);
157 	preempt_enable();
158 
159 	return IRQ_HANDLED;
160 }
161 
162 /* Deferred service handler, run as interrupt-fired tasklet */
163 static void caam_jr_dequeue(unsigned long devarg)
164 {
165 	int hw_idx, sw_idx, i, head, tail;
166 	struct device *dev = (struct device *)devarg;
167 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
168 	void (*usercall)(struct device *dev, u32 *desc, u32 status, void *arg);
169 	u32 *userdesc, userstatus;
170 	void *userarg;
171 
172 	while (rd_reg32(&jrp->rregs->outring_used)) {
173 
174 		head = ACCESS_ONCE(jrp->head);
175 
176 		spin_lock(&jrp->outlock);
177 
178 		sw_idx = tail = jrp->tail;
179 		hw_idx = jrp->out_ring_read_index;
180 
181 		for (i = 0; CIRC_CNT(head, tail + i, JOBR_DEPTH) >= 1; i++) {
182 			sw_idx = (tail + i) & (JOBR_DEPTH - 1);
183 
184 			smp_read_barrier_depends();
185 
186 			if (jrp->outring[hw_idx].desc ==
187 			    jrp->entinfo[sw_idx].desc_addr_dma)
188 				break; /* found */
189 		}
190 		/* we should never fail to find a matching descriptor */
191 		BUG_ON(CIRC_CNT(head, tail + i, JOBR_DEPTH) <= 0);
192 
193 		/* Unmap just-run descriptor so we can post-process */
194 		dma_unmap_single(dev, jrp->outring[hw_idx].desc,
195 				 jrp->entinfo[sw_idx].desc_size,
196 				 DMA_TO_DEVICE);
197 
198 		/* mark completed, avoid matching on a recycled desc addr */
199 		jrp->entinfo[sw_idx].desc_addr_dma = 0;
200 
201 		/* Stash callback params for use outside of lock */
202 		usercall = jrp->entinfo[sw_idx].callbk;
203 		userarg = jrp->entinfo[sw_idx].cbkarg;
204 		userdesc = jrp->entinfo[sw_idx].desc_addr_virt;
205 		userstatus = jrp->outring[hw_idx].jrstatus;
206 
207 		/* set done */
208 		wr_reg32(&jrp->rregs->outring_rmvd, 1);
209 
210 		jrp->out_ring_read_index = (jrp->out_ring_read_index + 1) &
211 					   (JOBR_DEPTH - 1);
212 
213 		/*
214 		 * if this job completed out-of-order, do not increment
215 		 * the tail.  Otherwise, increment tail by 1 plus the
216 		 * number of subsequent jobs already completed out-of-order
217 		 */
218 		if (sw_idx == tail) {
219 			do {
220 				tail = (tail + 1) & (JOBR_DEPTH - 1);
221 				smp_read_barrier_depends();
222 			} while (CIRC_CNT(head, tail, JOBR_DEPTH) >= 1 &&
223 				 jrp->entinfo[tail].desc_addr_dma == 0);
224 
225 			jrp->tail = tail;
226 		}
227 
228 		spin_unlock(&jrp->outlock);
229 
230 		/* Finally, execute user's callback */
231 		usercall(dev, userdesc, userstatus, userarg);
232 	}
233 
234 	/* reenable / unmask IRQs */
235 	clrbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);
236 }
237 
238 /**
239  * caam_jr_alloc() - Alloc a job ring for someone to use as needed.
240  *
241  * returns :  pointer to the newly allocated physical
242  *	      JobR dev can be written to if successful.
243  **/
244 struct device *caam_jr_alloc(void)
245 {
246 	struct caam_drv_private_jr *jrpriv, *min_jrpriv = NULL;
247 	struct device *dev = NULL;
248 	int min_tfm_cnt	= INT_MAX;
249 	int tfm_cnt;
250 
251 	spin_lock(&driver_data.jr_alloc_lock);
252 
253 	if (list_empty(&driver_data.jr_list)) {
254 		spin_unlock(&driver_data.jr_alloc_lock);
255 		return ERR_PTR(-ENODEV);
256 	}
257 
258 	list_for_each_entry(jrpriv, &driver_data.jr_list, list_node) {
259 		tfm_cnt = atomic_read(&jrpriv->tfm_count);
260 		if (tfm_cnt < min_tfm_cnt) {
261 			min_tfm_cnt = tfm_cnt;
262 			min_jrpriv = jrpriv;
263 		}
264 		if (!min_tfm_cnt)
265 			break;
266 	}
267 
268 	if (min_jrpriv) {
269 		atomic_inc(&min_jrpriv->tfm_count);
270 		dev = min_jrpriv->dev;
271 	}
272 	spin_unlock(&driver_data.jr_alloc_lock);
273 
274 	return dev;
275 }
276 EXPORT_SYMBOL(caam_jr_alloc);
277 
278 /**
279  * caam_jr_free() - Free the Job Ring
280  * @rdev     - points to the dev that identifies the Job ring to
281  *             be released.
282  **/
283 void caam_jr_free(struct device *rdev)
284 {
285 	struct caam_drv_private_jr *jrpriv = dev_get_drvdata(rdev);
286 
287 	atomic_dec(&jrpriv->tfm_count);
288 }
289 EXPORT_SYMBOL(caam_jr_free);
290 
291 /**
292  * caam_jr_enqueue() - Enqueue a job descriptor head. Returns 0 if OK,
293  * -EBUSY if the queue is full, -EIO if it cannot map the caller's
294  * descriptor.
295  * @dev:  device of the job ring to be used. This device should have
296  *        been assigned prior by caam_jr_register().
297  * @desc: points to a job descriptor that execute our request. All
298  *        descriptors (and all referenced data) must be in a DMAable
299  *        region, and all data references must be physical addresses
300  *        accessible to CAAM (i.e. within a PAMU window granted
301  *        to it).
302  * @cbk:  pointer to a callback function to be invoked upon completion
303  *        of this request. This has the form:
304  *        callback(struct device *dev, u32 *desc, u32 stat, void *arg)
305  *        where:
306  *        @dev:    contains the job ring device that processed this
307  *                 response.
308  *        @desc:   descriptor that initiated the request, same as
309  *                 "desc" being argued to caam_jr_enqueue().
310  *        @status: untranslated status received from CAAM. See the
311  *                 reference manual for a detailed description of
312  *                 error meaning, or see the JRSTA definitions in the
313  *                 register header file
314  *        @areq:   optional pointer to an argument passed with the
315  *                 original request
316  * @areq: optional pointer to a user argument for use at callback
317  *        time.
318  **/
319 int caam_jr_enqueue(struct device *dev, u32 *desc,
320 		    void (*cbk)(struct device *dev, u32 *desc,
321 				u32 status, void *areq),
322 		    void *areq)
323 {
324 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
325 	struct caam_jrentry_info *head_entry;
326 	int head, tail, desc_size;
327 	dma_addr_t desc_dma;
328 
329 	desc_size = (*desc & HDR_JD_LENGTH_MASK) * sizeof(u32);
330 	desc_dma = dma_map_single(dev, desc, desc_size, DMA_TO_DEVICE);
331 	if (dma_mapping_error(dev, desc_dma)) {
332 		dev_err(dev, "caam_jr_enqueue(): can't map jobdesc\n");
333 		return -EIO;
334 	}
335 
336 	spin_lock_bh(&jrp->inplock);
337 
338 	head = jrp->head;
339 	tail = ACCESS_ONCE(jrp->tail);
340 
341 	if (!rd_reg32(&jrp->rregs->inpring_avail) ||
342 	    CIRC_SPACE(head, tail, JOBR_DEPTH) <= 0) {
343 		spin_unlock_bh(&jrp->inplock);
344 		dma_unmap_single(dev, desc_dma, desc_size, DMA_TO_DEVICE);
345 		return -EBUSY;
346 	}
347 
348 	head_entry = &jrp->entinfo[head];
349 	head_entry->desc_addr_virt = desc;
350 	head_entry->desc_size = desc_size;
351 	head_entry->callbk = (void *)cbk;
352 	head_entry->cbkarg = areq;
353 	head_entry->desc_addr_dma = desc_dma;
354 
355 	jrp->inpring[jrp->inp_ring_write_index] = desc_dma;
356 
357 	smp_wmb();
358 
359 	jrp->inp_ring_write_index = (jrp->inp_ring_write_index + 1) &
360 				    (JOBR_DEPTH - 1);
361 	jrp->head = (head + 1) & (JOBR_DEPTH - 1);
362 
363 	wr_reg32(&jrp->rregs->inpring_jobadd, 1);
364 
365 	spin_unlock_bh(&jrp->inplock);
366 
367 	return 0;
368 }
369 EXPORT_SYMBOL(caam_jr_enqueue);
370 
371 /*
372  * Init JobR independent of platform property detection
373  */
374 static int caam_jr_init(struct device *dev)
375 {
376 	struct caam_drv_private_jr *jrp;
377 	dma_addr_t inpbusaddr, outbusaddr;
378 	int i, error;
379 
380 	jrp = dev_get_drvdata(dev);
381 
382 	tasklet_init(&jrp->irqtask, caam_jr_dequeue, (unsigned long)dev);
383 
384 	/* Connect job ring interrupt handler. */
385 	error = request_irq(jrp->irq, caam_jr_interrupt, IRQF_SHARED,
386 			    dev_name(dev), dev);
387 	if (error) {
388 		dev_err(dev, "can't connect JobR %d interrupt (%d)\n",
389 			jrp->ridx, jrp->irq);
390 		irq_dispose_mapping(jrp->irq);
391 		jrp->irq = 0;
392 		return -EINVAL;
393 	}
394 
395 	error = caam_reset_hw_jr(dev);
396 	if (error)
397 		return error;
398 
399 	jrp->inpring = dma_alloc_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
400 					  &inpbusaddr, GFP_KERNEL);
401 
402 	jrp->outring = dma_alloc_coherent(dev, sizeof(struct jr_outentry) *
403 					  JOBR_DEPTH, &outbusaddr, GFP_KERNEL);
404 
405 	jrp->entinfo = kzalloc(sizeof(struct caam_jrentry_info) * JOBR_DEPTH,
406 			       GFP_KERNEL);
407 
408 	if ((jrp->inpring == NULL) || (jrp->outring == NULL) ||
409 	    (jrp->entinfo == NULL)) {
410 		dev_err(dev, "can't allocate job rings for %d\n",
411 			jrp->ridx);
412 		return -ENOMEM;
413 	}
414 
415 	for (i = 0; i < JOBR_DEPTH; i++)
416 		jrp->entinfo[i].desc_addr_dma = !0;
417 
418 	/* Setup rings */
419 	jrp->inp_ring_write_index = 0;
420 	jrp->out_ring_read_index = 0;
421 	jrp->head = 0;
422 	jrp->tail = 0;
423 
424 	wr_reg64(&jrp->rregs->inpring_base, inpbusaddr);
425 	wr_reg64(&jrp->rregs->outring_base, outbusaddr);
426 	wr_reg32(&jrp->rregs->inpring_size, JOBR_DEPTH);
427 	wr_reg32(&jrp->rregs->outring_size, JOBR_DEPTH);
428 
429 	jrp->ringsize = JOBR_DEPTH;
430 
431 	spin_lock_init(&jrp->inplock);
432 	spin_lock_init(&jrp->outlock);
433 
434 	/* Select interrupt coalescing parameters */
435 	setbits32(&jrp->rregs->rconfig_lo, JOBR_INTC |
436 		  (JOBR_INTC_COUNT_THLD << JRCFG_ICDCT_SHIFT) |
437 		  (JOBR_INTC_TIME_THLD << JRCFG_ICTT_SHIFT));
438 
439 	return 0;
440 }
441 
442 
443 /*
444  * Probe routine for each detected JobR subsystem.
445  */
446 static int caam_jr_probe(struct platform_device *pdev)
447 {
448 	struct device *jrdev;
449 	struct device_node *nprop;
450 	struct caam_job_ring __iomem *ctrl;
451 	struct caam_drv_private_jr *jrpriv;
452 	static int total_jobrs;
453 	int error;
454 
455 	jrdev = &pdev->dev;
456 	jrpriv = devm_kmalloc(jrdev, sizeof(struct caam_drv_private_jr),
457 			      GFP_KERNEL);
458 	if (!jrpriv)
459 		return -ENOMEM;
460 
461 	dev_set_drvdata(jrdev, jrpriv);
462 
463 	/* save ring identity relative to detection */
464 	jrpriv->ridx = total_jobrs++;
465 
466 	nprop = pdev->dev.of_node;
467 	/* Get configuration properties from device tree */
468 	/* First, get register page */
469 	ctrl = of_iomap(nprop, 0);
470 	if (!ctrl) {
471 		dev_err(jrdev, "of_iomap() failed\n");
472 		return -ENOMEM;
473 	}
474 
475 	jrpriv->rregs = (struct caam_job_ring __force *)ctrl;
476 
477 	if (sizeof(dma_addr_t) == sizeof(u64))
478 		if (of_device_is_compatible(nprop, "fsl,sec-v5.0-job-ring"))
479 			dma_set_mask_and_coherent(jrdev, DMA_BIT_MASK(40));
480 		else
481 			dma_set_mask_and_coherent(jrdev, DMA_BIT_MASK(36));
482 	else
483 		dma_set_mask_and_coherent(jrdev, DMA_BIT_MASK(32));
484 
485 	/* Identify the interrupt */
486 	jrpriv->irq = irq_of_parse_and_map(nprop, 0);
487 
488 	/* Now do the platform independent part */
489 	error = caam_jr_init(jrdev); /* now turn on hardware */
490 	if (error)
491 		return error;
492 
493 	jrpriv->dev = jrdev;
494 	spin_lock(&driver_data.jr_alloc_lock);
495 	list_add_tail(&jrpriv->list_node, &driver_data.jr_list);
496 	spin_unlock(&driver_data.jr_alloc_lock);
497 
498 	atomic_set(&jrpriv->tfm_count, 0);
499 
500 	return 0;
501 }
502 
503 static struct of_device_id caam_jr_match[] = {
504 	{
505 		.compatible = "fsl,sec-v4.0-job-ring",
506 	},
507 	{
508 		.compatible = "fsl,sec4.0-job-ring",
509 	},
510 	{},
511 };
512 MODULE_DEVICE_TABLE(of, caam_jr_match);
513 
514 static struct platform_driver caam_jr_driver = {
515 	.driver = {
516 		.name = "caam_jr",
517 		.owner = THIS_MODULE,
518 		.of_match_table = caam_jr_match,
519 	},
520 	.probe       = caam_jr_probe,
521 	.remove      = caam_jr_remove,
522 };
523 
524 static int __init jr_driver_init(void)
525 {
526 	spin_lock_init(&driver_data.jr_alloc_lock);
527 	INIT_LIST_HEAD(&driver_data.jr_list);
528 	return platform_driver_register(&caam_jr_driver);
529 }
530 
531 static void __exit jr_driver_exit(void)
532 {
533 	platform_driver_unregister(&caam_jr_driver);
534 }
535 
536 module_init(jr_driver_init);
537 module_exit(jr_driver_exit);
538 
539 MODULE_LICENSE("GPL");
540 MODULE_DESCRIPTION("FSL CAAM JR request backend");
541 MODULE_AUTHOR("Freescale Semiconductor - NMG/STC");
542