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
17struct 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
23static struct jr_driver_data driver_data;
24
25static 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 */
68int 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
93static 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 */
125static 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 */
163static 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			    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 = 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	clrbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);
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 **/
248struct 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}
280EXPORT_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 **/
287void 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}
293EXPORT_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 **/
323int 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 = (*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] = 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}
384EXPORT_SYMBOL(caam_jr_enqueue);
385
386/*
387 * Init JobR independent of platform property detection
388 */
389static 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	setbits32(&jrp->rregs->rconfig_lo, JOBR_INTC |
448		  (JOBR_INTC_COUNT_THLD << JRCFG_ICDCT_SHIFT) |
449		  (JOBR_INTC_TIME_THLD << JRCFG_ICTT_SHIFT));
450
451	return 0;
452
453out_free_outring:
454	dma_free_coherent(dev, sizeof(struct jr_outentry) * JOBR_DEPTH,
455			  jrp->outring, outbusaddr);
456out_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);
460out_free_irq:
461	free_irq(jrp->irq, dev);
462out_kill_deq:
463	tasklet_kill(&jrp->irqtask);
464	return error;
465}
466
467
468/*
469 * Probe routine for each detected JobR subsystem.
470 */
471static 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		return error;
517	}
518
519	jrpriv->dev = jrdev;
520	spin_lock(&driver_data.jr_alloc_lock);
521	list_add_tail(&jrpriv->list_node, &driver_data.jr_list);
522	spin_unlock(&driver_data.jr_alloc_lock);
523
524	atomic_set(&jrpriv->tfm_count, 0);
525
526	return 0;
527}
528
529static struct of_device_id caam_jr_match[] = {
530	{
531		.compatible = "fsl,sec-v4.0-job-ring",
532	},
533	{
534		.compatible = "fsl,sec4.0-job-ring",
535	},
536	{},
537};
538MODULE_DEVICE_TABLE(of, caam_jr_match);
539
540static struct platform_driver caam_jr_driver = {
541	.driver = {
542		.name = "caam_jr",
543		.of_match_table = caam_jr_match,
544	},
545	.probe       = caam_jr_probe,
546	.remove      = caam_jr_remove,
547};
548
549static int __init jr_driver_init(void)
550{
551	spin_lock_init(&driver_data.jr_alloc_lock);
552	INIT_LIST_HEAD(&driver_data.jr_list);
553	return platform_driver_register(&caam_jr_driver);
554}
555
556static void __exit jr_driver_exit(void)
557{
558	platform_driver_unregister(&caam_jr_driver);
559}
560
561module_init(jr_driver_init);
562module_exit(jr_driver_exit);
563
564MODULE_LICENSE("GPL");
565MODULE_DESCRIPTION("FSL CAAM JR request backend");
566MODULE_AUTHOR("Freescale Semiconductor - NMG/STC");
567