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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 
caam_reset_hw_jr(struct device * dev)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  */
caam_jr_shutdown(struct device * dev)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 	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 
caam_jr_remove(struct platform_device * pdev)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 */
caam_jr_interrupt(int irq,void * st_dev)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 	clrsetbits_32(&jrp->rregs->rconfig_lo, 0, 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 */
caam_jr_dequeue(unsigned long devarg)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 			if (jrp->outring[hw_idx].desc ==
185 			    caam_dma_to_cpu(jrp->entinfo[sw_idx].desc_addr_dma))
186 				break; /* found */
187 		}
188 		/* we should never fail to find a matching descriptor */
189 		BUG_ON(CIRC_CNT(head, tail + i, JOBR_DEPTH) <= 0);
190 
191 		/* Unmap just-run descriptor so we can post-process */
192 		dma_unmap_single(dev, jrp->outring[hw_idx].desc,
193 				 jrp->entinfo[sw_idx].desc_size,
194 				 DMA_TO_DEVICE);
195 
196 		/* mark completed, avoid matching on a recycled desc addr */
197 		jrp->entinfo[sw_idx].desc_addr_dma = 0;
198 
199 		/* Stash callback params for use outside of lock */
200 		usercall = jrp->entinfo[sw_idx].callbk;
201 		userarg = jrp->entinfo[sw_idx].cbkarg;
202 		userdesc = jrp->entinfo[sw_idx].desc_addr_virt;
203 		userstatus = caam32_to_cpu(jrp->outring[hw_idx].jrstatus);
204 
205 		/*
206 		 * Make sure all information from the job has been obtained
207 		 * before telling CAAM that the job has been removed from the
208 		 * output ring.
209 		 */
210 		mb();
211 
212 		/* set done */
213 		wr_reg32(&jrp->rregs->outring_rmvd, 1);
214 
215 		jrp->out_ring_read_index = (jrp->out_ring_read_index + 1) &
216 					   (JOBR_DEPTH - 1);
217 
218 		/*
219 		 * if this job completed out-of-order, do not increment
220 		 * the tail.  Otherwise, increment tail by 1 plus the
221 		 * number of subsequent jobs already completed out-of-order
222 		 */
223 		if (sw_idx == tail) {
224 			do {
225 				tail = (tail + 1) & (JOBR_DEPTH - 1);
226 			} while (CIRC_CNT(head, tail, JOBR_DEPTH) >= 1 &&
227 				 jrp->entinfo[tail].desc_addr_dma == 0);
228 
229 			jrp->tail = tail;
230 		}
231 
232 		spin_unlock(&jrp->outlock);
233 
234 		/* Finally, execute user's callback */
235 		usercall(dev, userdesc, userstatus, userarg);
236 	}
237 
238 	/* reenable / unmask IRQs */
239 	clrsetbits_32(&jrp->rregs->rconfig_lo, JRCFG_IMSK, 0);
240 }
241 
242 /**
243  * caam_jr_alloc() - Alloc a job ring for someone to use as needed.
244  *
245  * returns :  pointer to the newly allocated physical
246  *	      JobR dev can be written to if successful.
247  **/
caam_jr_alloc(void)248 struct device *caam_jr_alloc(void)
249 {
250 	struct caam_drv_private_jr *jrpriv, *min_jrpriv = NULL;
251 	struct device *dev = ERR_PTR(-ENODEV);
252 	int min_tfm_cnt	= INT_MAX;
253 	int tfm_cnt;
254 
255 	spin_lock(&driver_data.jr_alloc_lock);
256 
257 	if (list_empty(&driver_data.jr_list)) {
258 		spin_unlock(&driver_data.jr_alloc_lock);
259 		return ERR_PTR(-ENODEV);
260 	}
261 
262 	list_for_each_entry(jrpriv, &driver_data.jr_list, list_node) {
263 		tfm_cnt = atomic_read(&jrpriv->tfm_count);
264 		if (tfm_cnt < min_tfm_cnt) {
265 			min_tfm_cnt = tfm_cnt;
266 			min_jrpriv = jrpriv;
267 		}
268 		if (!min_tfm_cnt)
269 			break;
270 	}
271 
272 	if (min_jrpriv) {
273 		atomic_inc(&min_jrpriv->tfm_count);
274 		dev = min_jrpriv->dev;
275 	}
276 	spin_unlock(&driver_data.jr_alloc_lock);
277 
278 	return dev;
279 }
280 EXPORT_SYMBOL(caam_jr_alloc);
281 
282 /**
283  * caam_jr_free() - Free the Job Ring
284  * @rdev     - points to the dev that identifies the Job ring to
285  *             be released.
286  **/
caam_jr_free(struct device * rdev)287 void caam_jr_free(struct device *rdev)
288 {
289 	struct caam_drv_private_jr *jrpriv = dev_get_drvdata(rdev);
290 
291 	atomic_dec(&jrpriv->tfm_count);
292 }
293 EXPORT_SYMBOL(caam_jr_free);
294 
295 /**
296  * caam_jr_enqueue() - Enqueue a job descriptor head. Returns 0 if OK,
297  * -EBUSY if the queue is full, -EIO if it cannot map the caller's
298  * descriptor.
299  * @dev:  device of the job ring to be used. This device should have
300  *        been assigned prior by caam_jr_register().
301  * @desc: points to a job descriptor that execute our request. All
302  *        descriptors (and all referenced data) must be in a DMAable
303  *        region, and all data references must be physical addresses
304  *        accessible to CAAM (i.e. within a PAMU window granted
305  *        to it).
306  * @cbk:  pointer to a callback function to be invoked upon completion
307  *        of this request. This has the form:
308  *        callback(struct device *dev, u32 *desc, u32 stat, void *arg)
309  *        where:
310  *        @dev:    contains the job ring device that processed this
311  *                 response.
312  *        @desc:   descriptor that initiated the request, same as
313  *                 "desc" being argued to caam_jr_enqueue().
314  *        @status: untranslated status received from CAAM. See the
315  *                 reference manual for a detailed description of
316  *                 error meaning, or see the JRSTA definitions in the
317  *                 register header file
318  *        @areq:   optional pointer to an argument passed with the
319  *                 original request
320  * @areq: optional pointer to a user argument for use at callback
321  *        time.
322  **/
caam_jr_enqueue(struct device * dev,u32 * desc,void (* cbk)(struct device * dev,u32 * desc,u32 status,void * areq),void * areq)323 int caam_jr_enqueue(struct device *dev, u32 *desc,
324 		    void (*cbk)(struct device *dev, u32 *desc,
325 				u32 status, void *areq),
326 		    void *areq)
327 {
328 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
329 	struct caam_jrentry_info *head_entry;
330 	int head, tail, desc_size;
331 	dma_addr_t desc_dma;
332 
333 	desc_size = (caam32_to_cpu(*desc) & HDR_JD_LENGTH_MASK) * sizeof(u32);
334 	desc_dma = dma_map_single(dev, desc, desc_size, DMA_TO_DEVICE);
335 	if (dma_mapping_error(dev, desc_dma)) {
336 		dev_err(dev, "caam_jr_enqueue(): can't map jobdesc\n");
337 		return -EIO;
338 	}
339 
340 	spin_lock_bh(&jrp->inplock);
341 
342 	head = jrp->head;
343 	tail = ACCESS_ONCE(jrp->tail);
344 
345 	if (!rd_reg32(&jrp->rregs->inpring_avail) ||
346 	    CIRC_SPACE(head, tail, JOBR_DEPTH) <= 0) {
347 		spin_unlock_bh(&jrp->inplock);
348 		dma_unmap_single(dev, desc_dma, desc_size, DMA_TO_DEVICE);
349 		return -EBUSY;
350 	}
351 
352 	head_entry = &jrp->entinfo[head];
353 	head_entry->desc_addr_virt = desc;
354 	head_entry->desc_size = desc_size;
355 	head_entry->callbk = (void *)cbk;
356 	head_entry->cbkarg = areq;
357 	head_entry->desc_addr_dma = desc_dma;
358 
359 	jrp->inpring[jrp->inp_ring_write_index] = cpu_to_caam_dma(desc_dma);
360 
361 	/*
362 	 * Guarantee that the descriptor's DMA address has been written to
363 	 * the next slot in the ring before the write index is updated, since
364 	 * other cores may update this index independently.
365 	 */
366 	smp_wmb();
367 
368 	jrp->inp_ring_write_index = (jrp->inp_ring_write_index + 1) &
369 				    (JOBR_DEPTH - 1);
370 	jrp->head = (head + 1) & (JOBR_DEPTH - 1);
371 
372 	/*
373 	 * Ensure that all job information has been written before
374 	 * notifying CAAM that a new job was added to the input ring.
375 	 */
376 	wmb();
377 
378 	wr_reg32(&jrp->rregs->inpring_jobadd, 1);
379 
380 	spin_unlock_bh(&jrp->inplock);
381 
382 	return 0;
383 }
384 EXPORT_SYMBOL(caam_jr_enqueue);
385 
386 /*
387  * Init JobR independent of platform property detection
388  */
caam_jr_init(struct device * dev)389 static int caam_jr_init(struct device *dev)
390 {
391 	struct caam_drv_private_jr *jrp;
392 	dma_addr_t inpbusaddr, outbusaddr;
393 	int i, error;
394 
395 	jrp = dev_get_drvdata(dev);
396 
397 	tasklet_init(&jrp->irqtask, caam_jr_dequeue, (unsigned long)dev);
398 
399 	/* Connect job ring interrupt handler. */
400 	error = request_irq(jrp->irq, caam_jr_interrupt, IRQF_SHARED,
401 			    dev_name(dev), dev);
402 	if (error) {
403 		dev_err(dev, "can't connect JobR %d interrupt (%d)\n",
404 			jrp->ridx, jrp->irq);
405 		goto out_kill_deq;
406 	}
407 
408 	error = caam_reset_hw_jr(dev);
409 	if (error)
410 		goto out_free_irq;
411 
412 	error = -ENOMEM;
413 	jrp->inpring = dma_alloc_coherent(dev, sizeof(*jrp->inpring) *
414 					  JOBR_DEPTH, &inpbusaddr, GFP_KERNEL);
415 	if (!jrp->inpring)
416 		goto out_free_irq;
417 
418 	jrp->outring = dma_alloc_coherent(dev, sizeof(*jrp->outring) *
419 					  JOBR_DEPTH, &outbusaddr, GFP_KERNEL);
420 	if (!jrp->outring)
421 		goto out_free_inpring;
422 
423 	jrp->entinfo = kcalloc(JOBR_DEPTH, sizeof(*jrp->entinfo), GFP_KERNEL);
424 	if (!jrp->entinfo)
425 		goto out_free_outring;
426 
427 	for (i = 0; i < JOBR_DEPTH; i++)
428 		jrp->entinfo[i].desc_addr_dma = !0;
429 
430 	/* Setup rings */
431 	jrp->inp_ring_write_index = 0;
432 	jrp->out_ring_read_index = 0;
433 	jrp->head = 0;
434 	jrp->tail = 0;
435 
436 	wr_reg64(&jrp->rregs->inpring_base, inpbusaddr);
437 	wr_reg64(&jrp->rregs->outring_base, outbusaddr);
438 	wr_reg32(&jrp->rregs->inpring_size, JOBR_DEPTH);
439 	wr_reg32(&jrp->rregs->outring_size, JOBR_DEPTH);
440 
441 	jrp->ringsize = JOBR_DEPTH;
442 
443 	spin_lock_init(&jrp->inplock);
444 	spin_lock_init(&jrp->outlock);
445 
446 	/* Select interrupt coalescing parameters */
447 	clrsetbits_32(&jrp->rregs->rconfig_lo, 0, JOBR_INTC |
448 		      (JOBR_INTC_COUNT_THLD << JRCFG_ICDCT_SHIFT) |
449 		      (JOBR_INTC_TIME_THLD << JRCFG_ICTT_SHIFT));
450 
451 	return 0;
452 
453 out_free_outring:
454 	dma_free_coherent(dev, sizeof(struct jr_outentry) * JOBR_DEPTH,
455 			  jrp->outring, outbusaddr);
456 out_free_inpring:
457 	dma_free_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
458 			  jrp->inpring, inpbusaddr);
459 	dev_err(dev, "can't allocate job rings for %d\n", jrp->ridx);
460 out_free_irq:
461 	free_irq(jrp->irq, dev);
462 out_kill_deq:
463 	tasklet_kill(&jrp->irqtask);
464 	return error;
465 }
466 
467 
468 /*
469  * Probe routine for each detected JobR subsystem.
470  */
caam_jr_probe(struct platform_device * pdev)471 static int caam_jr_probe(struct platform_device *pdev)
472 {
473 	struct device *jrdev;
474 	struct device_node *nprop;
475 	struct caam_job_ring __iomem *ctrl;
476 	struct caam_drv_private_jr *jrpriv;
477 	static int total_jobrs;
478 	int error;
479 
480 	jrdev = &pdev->dev;
481 	jrpriv = devm_kmalloc(jrdev, sizeof(*jrpriv), GFP_KERNEL);
482 	if (!jrpriv)
483 		return -ENOMEM;
484 
485 	dev_set_drvdata(jrdev, jrpriv);
486 
487 	/* save ring identity relative to detection */
488 	jrpriv->ridx = total_jobrs++;
489 
490 	nprop = pdev->dev.of_node;
491 	/* Get configuration properties from device tree */
492 	/* First, get register page */
493 	ctrl = of_iomap(nprop, 0);
494 	if (!ctrl) {
495 		dev_err(jrdev, "of_iomap() failed\n");
496 		return -ENOMEM;
497 	}
498 
499 	jrpriv->rregs = (struct caam_job_ring __force *)ctrl;
500 
501 	if (sizeof(dma_addr_t) == sizeof(u64))
502 		if (of_device_is_compatible(nprop, "fsl,sec-v5.0-job-ring"))
503 			dma_set_mask_and_coherent(jrdev, DMA_BIT_MASK(40));
504 		else
505 			dma_set_mask_and_coherent(jrdev, DMA_BIT_MASK(36));
506 	else
507 		dma_set_mask_and_coherent(jrdev, DMA_BIT_MASK(32));
508 
509 	/* Identify the interrupt */
510 	jrpriv->irq = irq_of_parse_and_map(nprop, 0);
511 
512 	/* Now do the platform independent part */
513 	error = caam_jr_init(jrdev); /* now turn on hardware */
514 	if (error) {
515 		irq_dispose_mapping(jrpriv->irq);
516 		iounmap(ctrl);
517 		return error;
518 	}
519 
520 	jrpriv->dev = jrdev;
521 	spin_lock(&driver_data.jr_alloc_lock);
522 	list_add_tail(&jrpriv->list_node, &driver_data.jr_list);
523 	spin_unlock(&driver_data.jr_alloc_lock);
524 
525 	atomic_set(&jrpriv->tfm_count, 0);
526 
527 	return 0;
528 }
529 
530 static struct of_device_id caam_jr_match[] = {
531 	{
532 		.compatible = "fsl,sec-v4.0-job-ring",
533 	},
534 	{
535 		.compatible = "fsl,sec4.0-job-ring",
536 	},
537 	{},
538 };
539 MODULE_DEVICE_TABLE(of, caam_jr_match);
540 
541 static struct platform_driver caam_jr_driver = {
542 	.driver = {
543 		.name = "caam_jr",
544 		.of_match_table = caam_jr_match,
545 	},
546 	.probe       = caam_jr_probe,
547 	.remove      = caam_jr_remove,
548 };
549 
jr_driver_init(void)550 static int __init jr_driver_init(void)
551 {
552 	spin_lock_init(&driver_data.jr_alloc_lock);
553 	INIT_LIST_HEAD(&driver_data.jr_list);
554 	return platform_driver_register(&caam_jr_driver);
555 }
556 
jr_driver_exit(void)557 static void __exit jr_driver_exit(void)
558 {
559 	platform_driver_unregister(&caam_jr_driver);
560 }
561 
562 module_init(jr_driver_init);
563 module_exit(jr_driver_exit);
564 
565 MODULE_LICENSE("GPL");
566 MODULE_DESCRIPTION("FSL CAAM JR request backend");
567 MODULE_AUTHOR("Freescale Semiconductor - NMG/STC");
568