xref: /openbmc/linux/drivers/crypto/caam/jr.c (revision 95e9fd10)
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 "compat.h"
9 #include "regs.h"
10 #include "jr.h"
11 #include "desc.h"
12 #include "intern.h"
13 
14 /* Main per-ring interrupt handler */
15 static irqreturn_t caam_jr_interrupt(int irq, void *st_dev)
16 {
17 	struct device *dev = st_dev;
18 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
19 	u32 irqstate;
20 
21 	/*
22 	 * Check the output ring for ready responses, kick
23 	 * tasklet if jobs done.
24 	 */
25 	irqstate = rd_reg32(&jrp->rregs->jrintstatus);
26 	if (!irqstate)
27 		return IRQ_NONE;
28 
29 	/*
30 	 * If JobR error, we got more development work to do
31 	 * Flag a bug now, but we really need to shut down and
32 	 * restart the queue (and fix code).
33 	 */
34 	if (irqstate & JRINT_JR_ERROR) {
35 		dev_err(dev, "job ring error: irqstate: %08x\n", irqstate);
36 		BUG();
37 	}
38 
39 	/* mask valid interrupts */
40 	setbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);
41 
42 	/* Have valid interrupt at this point, just ACK and trigger */
43 	wr_reg32(&jrp->rregs->jrintstatus, irqstate);
44 
45 	preempt_disable();
46 	tasklet_schedule(&jrp->irqtask);
47 	preempt_enable();
48 
49 	return IRQ_HANDLED;
50 }
51 
52 /* Deferred service handler, run as interrupt-fired tasklet */
53 static void caam_jr_dequeue(unsigned long devarg)
54 {
55 	int hw_idx, sw_idx, i, head, tail;
56 	struct device *dev = (struct device *)devarg;
57 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
58 	void (*usercall)(struct device *dev, u32 *desc, u32 status, void *arg);
59 	u32 *userdesc, userstatus;
60 	void *userarg;
61 
62 	while (rd_reg32(&jrp->rregs->outring_used)) {
63 
64 		head = ACCESS_ONCE(jrp->head);
65 
66 		spin_lock(&jrp->outlock);
67 
68 		sw_idx = tail = jrp->tail;
69 		hw_idx = jrp->out_ring_read_index;
70 
71 		for (i = 0; CIRC_CNT(head, tail + i, JOBR_DEPTH) >= 1; i++) {
72 			sw_idx = (tail + i) & (JOBR_DEPTH - 1);
73 
74 			smp_read_barrier_depends();
75 
76 			if (jrp->outring[hw_idx].desc ==
77 			    jrp->entinfo[sw_idx].desc_addr_dma)
78 				break; /* found */
79 		}
80 		/* we should never fail to find a matching descriptor */
81 		BUG_ON(CIRC_CNT(head, tail + i, JOBR_DEPTH) <= 0);
82 
83 		/* Unmap just-run descriptor so we can post-process */
84 		dma_unmap_single(dev, jrp->outring[hw_idx].desc,
85 				 jrp->entinfo[sw_idx].desc_size,
86 				 DMA_TO_DEVICE);
87 
88 		/* mark completed, avoid matching on a recycled desc addr */
89 		jrp->entinfo[sw_idx].desc_addr_dma = 0;
90 
91 		/* Stash callback params for use outside of lock */
92 		usercall = jrp->entinfo[sw_idx].callbk;
93 		userarg = jrp->entinfo[sw_idx].cbkarg;
94 		userdesc = jrp->entinfo[sw_idx].desc_addr_virt;
95 		userstatus = jrp->outring[hw_idx].jrstatus;
96 
97 		/* set done */
98 		wr_reg32(&jrp->rregs->outring_rmvd, 1);
99 
100 		jrp->out_ring_read_index = (jrp->out_ring_read_index + 1) &
101 					   (JOBR_DEPTH - 1);
102 
103 		/*
104 		 * if this job completed out-of-order, do not increment
105 		 * the tail.  Otherwise, increment tail by 1 plus the
106 		 * number of subsequent jobs already completed out-of-order
107 		 */
108 		if (sw_idx == tail) {
109 			do {
110 				tail = (tail + 1) & (JOBR_DEPTH - 1);
111 				smp_read_barrier_depends();
112 			} while (CIRC_CNT(head, tail, JOBR_DEPTH) >= 1 &&
113 				 jrp->entinfo[tail].desc_addr_dma == 0);
114 
115 			jrp->tail = tail;
116 		}
117 
118 		spin_unlock(&jrp->outlock);
119 
120 		/* Finally, execute user's callback */
121 		usercall(dev, userdesc, userstatus, userarg);
122 	}
123 
124 	/* reenable / unmask IRQs */
125 	clrbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);
126 }
127 
128 /**
129  * caam_jr_register() - Alloc a ring for someone to use as needed. Returns
130  * an ordinal of the rings allocated, else returns -ENODEV if no rings
131  * are available.
132  * @ctrldev: points to the controller level dev (parent) that
133  *           owns rings available for use.
134  * @dev:     points to where a pointer to the newly allocated queue's
135  *           dev can be written to if successful.
136  **/
137 int caam_jr_register(struct device *ctrldev, struct device **rdev)
138 {
139 	struct caam_drv_private *ctrlpriv = dev_get_drvdata(ctrldev);
140 	struct caam_drv_private_jr *jrpriv = NULL;
141 	int ring;
142 
143 	/* Lock, if free ring - assign, unlock */
144 	spin_lock(&ctrlpriv->jr_alloc_lock);
145 	for (ring = 0; ring < ctrlpriv->total_jobrs; ring++) {
146 		jrpriv = dev_get_drvdata(ctrlpriv->jrdev[ring]);
147 		if (jrpriv->assign == JOBR_UNASSIGNED) {
148 			jrpriv->assign = JOBR_ASSIGNED;
149 			*rdev = ctrlpriv->jrdev[ring];
150 			spin_unlock(&ctrlpriv->jr_alloc_lock);
151 			return ring;
152 		}
153 	}
154 
155 	/* If assigned, write dev where caller needs it */
156 	spin_unlock(&ctrlpriv->jr_alloc_lock);
157 	*rdev = NULL;
158 
159 	return -ENODEV;
160 }
161 EXPORT_SYMBOL(caam_jr_register);
162 
163 /**
164  * caam_jr_deregister() - Deregister an API and release the queue.
165  * Returns 0 if OK, -EBUSY if queue still contains pending entries
166  * or unprocessed results at the time of the call
167  * @dev     - points to the dev that identifies the queue to
168  *            be released.
169  **/
170 int caam_jr_deregister(struct device *rdev)
171 {
172 	struct caam_drv_private_jr *jrpriv = dev_get_drvdata(rdev);
173 	struct caam_drv_private *ctrlpriv;
174 
175 	/* Get the owning controller's private space */
176 	ctrlpriv = dev_get_drvdata(jrpriv->parentdev);
177 
178 	/*
179 	 * Make sure ring empty before release
180 	 */
181 	if (rd_reg32(&jrpriv->rregs->outring_used) ||
182 	    (rd_reg32(&jrpriv->rregs->inpring_avail) != JOBR_DEPTH))
183 		return -EBUSY;
184 
185 	/* Release ring */
186 	spin_lock(&ctrlpriv->jr_alloc_lock);
187 	jrpriv->assign = JOBR_UNASSIGNED;
188 	spin_unlock(&ctrlpriv->jr_alloc_lock);
189 
190 	return 0;
191 }
192 EXPORT_SYMBOL(caam_jr_deregister);
193 
194 /**
195  * caam_jr_enqueue() - Enqueue a job descriptor head. Returns 0 if OK,
196  * -EBUSY if the queue is full, -EIO if it cannot map the caller's
197  * descriptor.
198  * @dev:  device of the job ring to be used. This device should have
199  *        been assigned prior by caam_jr_register().
200  * @desc: points to a job descriptor that execute our request. All
201  *        descriptors (and all referenced data) must be in a DMAable
202  *        region, and all data references must be physical addresses
203  *        accessible to CAAM (i.e. within a PAMU window granted
204  *        to it).
205  * @cbk:  pointer to a callback function to be invoked upon completion
206  *        of this request. This has the form:
207  *        callback(struct device *dev, u32 *desc, u32 stat, void *arg)
208  *        where:
209  *        @dev:    contains the job ring device that processed this
210  *                 response.
211  *        @desc:   descriptor that initiated the request, same as
212  *                 "desc" being argued to caam_jr_enqueue().
213  *        @status: untranslated status received from CAAM. See the
214  *                 reference manual for a detailed description of
215  *                 error meaning, or see the JRSTA definitions in the
216  *                 register header file
217  *        @areq:   optional pointer to an argument passed with the
218  *                 original request
219  * @areq: optional pointer to a user argument for use at callback
220  *        time.
221  **/
222 int caam_jr_enqueue(struct device *dev, u32 *desc,
223 		    void (*cbk)(struct device *dev, u32 *desc,
224 				u32 status, void *areq),
225 		    void *areq)
226 {
227 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
228 	struct caam_jrentry_info *head_entry;
229 	int head, tail, desc_size;
230 	dma_addr_t desc_dma;
231 
232 	desc_size = (*desc & HDR_JD_LENGTH_MASK) * sizeof(u32);
233 	desc_dma = dma_map_single(dev, desc, desc_size, DMA_TO_DEVICE);
234 	if (dma_mapping_error(dev, desc_dma)) {
235 		dev_err(dev, "caam_jr_enqueue(): can't map jobdesc\n");
236 		return -EIO;
237 	}
238 
239 	spin_lock_bh(&jrp->inplock);
240 
241 	head = jrp->head;
242 	tail = ACCESS_ONCE(jrp->tail);
243 
244 	if (!rd_reg32(&jrp->rregs->inpring_avail) ||
245 	    CIRC_SPACE(head, tail, JOBR_DEPTH) <= 0) {
246 		spin_unlock_bh(&jrp->inplock);
247 		dma_unmap_single(dev, desc_dma, desc_size, DMA_TO_DEVICE);
248 		return -EBUSY;
249 	}
250 
251 	head_entry = &jrp->entinfo[head];
252 	head_entry->desc_addr_virt = desc;
253 	head_entry->desc_size = desc_size;
254 	head_entry->callbk = (void *)cbk;
255 	head_entry->cbkarg = areq;
256 	head_entry->desc_addr_dma = desc_dma;
257 
258 	jrp->inpring[jrp->inp_ring_write_index] = desc_dma;
259 
260 	smp_wmb();
261 
262 	jrp->inp_ring_write_index = (jrp->inp_ring_write_index + 1) &
263 				    (JOBR_DEPTH - 1);
264 	jrp->head = (head + 1) & (JOBR_DEPTH - 1);
265 
266 	wr_reg32(&jrp->rregs->inpring_jobadd, 1);
267 
268 	spin_unlock_bh(&jrp->inplock);
269 
270 	return 0;
271 }
272 EXPORT_SYMBOL(caam_jr_enqueue);
273 
274 static int caam_reset_hw_jr(struct device *dev)
275 {
276 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
277 	unsigned int timeout = 100000;
278 
279 	/*
280 	 * mask interrupts since we are going to poll
281 	 * for reset completion status
282 	 */
283 	setbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);
284 
285 	/* initiate flush (required prior to reset) */
286 	wr_reg32(&jrp->rregs->jrcommand, JRCR_RESET);
287 	while (((rd_reg32(&jrp->rregs->jrintstatus) & JRINT_ERR_HALT_MASK) ==
288 		JRINT_ERR_HALT_INPROGRESS) && --timeout)
289 		cpu_relax();
290 
291 	if ((rd_reg32(&jrp->rregs->jrintstatus) & JRINT_ERR_HALT_MASK) !=
292 	    JRINT_ERR_HALT_COMPLETE || timeout == 0) {
293 		dev_err(dev, "failed to flush job ring %d\n", jrp->ridx);
294 		return -EIO;
295 	}
296 
297 	/* initiate reset */
298 	timeout = 100000;
299 	wr_reg32(&jrp->rregs->jrcommand, JRCR_RESET);
300 	while ((rd_reg32(&jrp->rregs->jrcommand) & JRCR_RESET) && --timeout)
301 		cpu_relax();
302 
303 	if (timeout == 0) {
304 		dev_err(dev, "failed to reset job ring %d\n", jrp->ridx);
305 		return -EIO;
306 	}
307 
308 	/* unmask interrupts */
309 	clrbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);
310 
311 	return 0;
312 }
313 
314 /*
315  * Init JobR independent of platform property detection
316  */
317 static int caam_jr_init(struct device *dev)
318 {
319 	struct caam_drv_private_jr *jrp;
320 	dma_addr_t inpbusaddr, outbusaddr;
321 	int i, error;
322 
323 	jrp = dev_get_drvdata(dev);
324 
325 	tasklet_init(&jrp->irqtask, caam_jr_dequeue, (unsigned long)dev);
326 
327 	/* Connect job ring interrupt handler. */
328 	error = request_irq(jrp->irq, caam_jr_interrupt, IRQF_SHARED,
329 			    "caam-jobr", dev);
330 	if (error) {
331 		dev_err(dev, "can't connect JobR %d interrupt (%d)\n",
332 			jrp->ridx, jrp->irq);
333 		irq_dispose_mapping(jrp->irq);
334 		jrp->irq = 0;
335 		return -EINVAL;
336 	}
337 
338 	error = caam_reset_hw_jr(dev);
339 	if (error)
340 		return error;
341 
342 	jrp->inpring = dma_alloc_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
343 					  &inpbusaddr, GFP_KERNEL);
344 
345 	jrp->outring = dma_alloc_coherent(dev, sizeof(struct jr_outentry) *
346 					  JOBR_DEPTH, &outbusaddr, GFP_KERNEL);
347 
348 	jrp->entinfo = kzalloc(sizeof(struct caam_jrentry_info) * JOBR_DEPTH,
349 			       GFP_KERNEL);
350 
351 	if ((jrp->inpring == NULL) || (jrp->outring == NULL) ||
352 	    (jrp->entinfo == NULL)) {
353 		dev_err(dev, "can't allocate job rings for %d\n",
354 			jrp->ridx);
355 		return -ENOMEM;
356 	}
357 
358 	for (i = 0; i < JOBR_DEPTH; i++)
359 		jrp->entinfo[i].desc_addr_dma = !0;
360 
361 	/* Setup rings */
362 	jrp->inp_ring_write_index = 0;
363 	jrp->out_ring_read_index = 0;
364 	jrp->head = 0;
365 	jrp->tail = 0;
366 
367 	wr_reg64(&jrp->rregs->inpring_base, inpbusaddr);
368 	wr_reg64(&jrp->rregs->outring_base, outbusaddr);
369 	wr_reg32(&jrp->rregs->inpring_size, JOBR_DEPTH);
370 	wr_reg32(&jrp->rregs->outring_size, JOBR_DEPTH);
371 
372 	jrp->ringsize = JOBR_DEPTH;
373 
374 	spin_lock_init(&jrp->inplock);
375 	spin_lock_init(&jrp->outlock);
376 
377 	/* Select interrupt coalescing parameters */
378 	setbits32(&jrp->rregs->rconfig_lo, JOBR_INTC |
379 		  (JOBR_INTC_COUNT_THLD << JRCFG_ICDCT_SHIFT) |
380 		  (JOBR_INTC_TIME_THLD << JRCFG_ICTT_SHIFT));
381 
382 	jrp->assign = JOBR_UNASSIGNED;
383 	return 0;
384 }
385 
386 /*
387  * Shutdown JobR independent of platform property code
388  */
389 int caam_jr_shutdown(struct device *dev)
390 {
391 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
392 	dma_addr_t inpbusaddr, outbusaddr;
393 	int ret;
394 
395 	ret = caam_reset_hw_jr(dev);
396 
397 	tasklet_kill(&jrp->irqtask);
398 
399 	/* Release interrupt */
400 	free_irq(jrp->irq, dev);
401 
402 	/* Free rings */
403 	inpbusaddr = rd_reg64(&jrp->rregs->inpring_base);
404 	outbusaddr = rd_reg64(&jrp->rregs->outring_base);
405 	dma_free_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
406 			  jrp->inpring, inpbusaddr);
407 	dma_free_coherent(dev, sizeof(struct jr_outentry) * JOBR_DEPTH,
408 			  jrp->outring, outbusaddr);
409 	kfree(jrp->entinfo);
410 
411 	return ret;
412 }
413 
414 /*
415  * Probe routine for each detected JobR subsystem. It assumes that
416  * property detection was picked up externally.
417  */
418 int caam_jr_probe(struct platform_device *pdev, struct device_node *np,
419 		  int ring)
420 {
421 	struct device *ctrldev, *jrdev;
422 	struct platform_device *jr_pdev;
423 	struct caam_drv_private *ctrlpriv;
424 	struct caam_drv_private_jr *jrpriv;
425 	u32 *jroffset;
426 	int error;
427 
428 	ctrldev = &pdev->dev;
429 	ctrlpriv = dev_get_drvdata(ctrldev);
430 
431 	jrpriv = kmalloc(sizeof(struct caam_drv_private_jr),
432 			 GFP_KERNEL);
433 	if (jrpriv == NULL) {
434 		dev_err(ctrldev, "can't alloc private mem for job ring %d\n",
435 			ring);
436 		return -ENOMEM;
437 	}
438 	jrpriv->parentdev = ctrldev; /* point back to parent */
439 	jrpriv->ridx = ring; /* save ring identity relative to detection */
440 
441 	/*
442 	 * Derive a pointer to the detected JobRs regs
443 	 * Driver has already iomapped the entire space, we just
444 	 * need to add in the offset to this JobR. Don't know if I
445 	 * like this long-term, but it'll run
446 	 */
447 	jroffset = (u32 *)of_get_property(np, "reg", NULL);
448 	jrpriv->rregs = (struct caam_job_ring __iomem *)((void *)ctrlpriv->ctrl
449 							 + *jroffset);
450 
451 	/* Build a local dev for each detected queue */
452 	jr_pdev = of_platform_device_create(np, NULL, ctrldev);
453 	if (jr_pdev == NULL) {
454 		kfree(jrpriv);
455 		return -EINVAL;
456 	}
457 	jrdev = &jr_pdev->dev;
458 	dev_set_drvdata(jrdev, jrpriv);
459 	ctrlpriv->jrdev[ring] = jrdev;
460 
461 	if (sizeof(dma_addr_t) == sizeof(u64))
462 		if (of_device_is_compatible(np, "fsl,sec-v5.0-job-ring"))
463 			dma_set_mask(jrdev, DMA_BIT_MASK(40));
464 		else
465 			dma_set_mask(jrdev, DMA_BIT_MASK(36));
466 	else
467 		dma_set_mask(jrdev, DMA_BIT_MASK(32));
468 
469 	/* Identify the interrupt */
470 	jrpriv->irq = of_irq_to_resource(np, 0, NULL);
471 
472 	/* Now do the platform independent part */
473 	error = caam_jr_init(jrdev); /* now turn on hardware */
474 	if (error) {
475 		kfree(jrpriv);
476 		return error;
477 	}
478 
479 	return error;
480 }
481