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		/* 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	clrbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);
233}
234
235/**
236 * caam_jr_alloc() - Alloc a job ring for someone to use as needed.
237 *
238 * returns :  pointer to the newly allocated physical
239 *	      JobR dev can be written to if successful.
240 **/
241struct device *caam_jr_alloc(void)
242{
243	struct caam_drv_private_jr *jrpriv, *min_jrpriv = NULL;
244	struct device *dev = ERR_PTR(-ENODEV);
245	int min_tfm_cnt	= INT_MAX;
246	int tfm_cnt;
247
248	spin_lock(&driver_data.jr_alloc_lock);
249
250	if (list_empty(&driver_data.jr_list)) {
251		spin_unlock(&driver_data.jr_alloc_lock);
252		return ERR_PTR(-ENODEV);
253	}
254
255	list_for_each_entry(jrpriv, &driver_data.jr_list, list_node) {
256		tfm_cnt = atomic_read(&jrpriv->tfm_count);
257		if (tfm_cnt < min_tfm_cnt) {
258			min_tfm_cnt = tfm_cnt;
259			min_jrpriv = jrpriv;
260		}
261		if (!min_tfm_cnt)
262			break;
263	}
264
265	if (min_jrpriv) {
266		atomic_inc(&min_jrpriv->tfm_count);
267		dev = min_jrpriv->dev;
268	}
269	spin_unlock(&driver_data.jr_alloc_lock);
270
271	return dev;
272}
273EXPORT_SYMBOL(caam_jr_alloc);
274
275/**
276 * caam_jr_free() - Free the Job Ring
277 * @rdev     - points to the dev that identifies the Job ring to
278 *             be released.
279 **/
280void caam_jr_free(struct device *rdev)
281{
282	struct caam_drv_private_jr *jrpriv = dev_get_drvdata(rdev);
283
284	atomic_dec(&jrpriv->tfm_count);
285}
286EXPORT_SYMBOL(caam_jr_free);
287
288/**
289 * caam_jr_enqueue() - Enqueue a job descriptor head. Returns 0 if OK,
290 * -EBUSY if the queue is full, -EIO if it cannot map the caller's
291 * descriptor.
292 * @dev:  device of the job ring to be used. This device should have
293 *        been assigned prior by caam_jr_register().
294 * @desc: points to a job descriptor that execute our request. All
295 *        descriptors (and all referenced data) must be in a DMAable
296 *        region, and all data references must be physical addresses
297 *        accessible to CAAM (i.e. within a PAMU window granted
298 *        to it).
299 * @cbk:  pointer to a callback function to be invoked upon completion
300 *        of this request. This has the form:
301 *        callback(struct device *dev, u32 *desc, u32 stat, void *arg)
302 *        where:
303 *        @dev:    contains the job ring device that processed this
304 *                 response.
305 *        @desc:   descriptor that initiated the request, same as
306 *                 "desc" being argued to caam_jr_enqueue().
307 *        @status: untranslated status received from CAAM. See the
308 *                 reference manual for a detailed description of
309 *                 error meaning, or see the JRSTA definitions in the
310 *                 register header file
311 *        @areq:   optional pointer to an argument passed with the
312 *                 original request
313 * @areq: optional pointer to a user argument for use at callback
314 *        time.
315 **/
316int caam_jr_enqueue(struct device *dev, u32 *desc,
317		    void (*cbk)(struct device *dev, u32 *desc,
318				u32 status, void *areq),
319		    void *areq)
320{
321	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
322	struct caam_jrentry_info *head_entry;
323	int head, tail, desc_size;
324	dma_addr_t desc_dma;
325
326	desc_size = (*desc & HDR_JD_LENGTH_MASK) * sizeof(u32);
327	desc_dma = dma_map_single(dev, desc, desc_size, DMA_TO_DEVICE);
328	if (dma_mapping_error(dev, desc_dma)) {
329		dev_err(dev, "caam_jr_enqueue(): can't map jobdesc\n");
330		return -EIO;
331	}
332
333	spin_lock_bh(&jrp->inplock);
334
335	head = jrp->head;
336	tail = ACCESS_ONCE(jrp->tail);
337
338	if (!rd_reg32(&jrp->rregs->inpring_avail) ||
339	    CIRC_SPACE(head, tail, JOBR_DEPTH) <= 0) {
340		spin_unlock_bh(&jrp->inplock);
341		dma_unmap_single(dev, desc_dma, desc_size, DMA_TO_DEVICE);
342		return -EBUSY;
343	}
344
345	head_entry = &jrp->entinfo[head];
346	head_entry->desc_addr_virt = desc;
347	head_entry->desc_size = desc_size;
348	head_entry->callbk = (void *)cbk;
349	head_entry->cbkarg = areq;
350	head_entry->desc_addr_dma = desc_dma;
351
352	jrp->inpring[jrp->inp_ring_write_index] = desc_dma;
353
354	smp_wmb();
355
356	jrp->inp_ring_write_index = (jrp->inp_ring_write_index + 1) &
357				    (JOBR_DEPTH - 1);
358	jrp->head = (head + 1) & (JOBR_DEPTH - 1);
359
360	wr_reg32(&jrp->rregs->inpring_jobadd, 1);
361
362	spin_unlock_bh(&jrp->inplock);
363
364	return 0;
365}
366EXPORT_SYMBOL(caam_jr_enqueue);
367
368/*
369 * Init JobR independent of platform property detection
370 */
371static int caam_jr_init(struct device *dev)
372{
373	struct caam_drv_private_jr *jrp;
374	dma_addr_t inpbusaddr, outbusaddr;
375	int i, error;
376
377	jrp = dev_get_drvdata(dev);
378
379	tasklet_init(&jrp->irqtask, caam_jr_dequeue, (unsigned long)dev);
380
381	/* Connect job ring interrupt handler. */
382	error = request_irq(jrp->irq, caam_jr_interrupt, IRQF_SHARED,
383			    dev_name(dev), dev);
384	if (error) {
385		dev_err(dev, "can't connect JobR %d interrupt (%d)\n",
386			jrp->ridx, jrp->irq);
387		goto out_kill_deq;
388	}
389
390	error = caam_reset_hw_jr(dev);
391	if (error)
392		goto out_free_irq;
393
394	error = -ENOMEM;
395	jrp->inpring = dma_alloc_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
396					  &inpbusaddr, GFP_KERNEL);
397	if (!jrp->inpring)
398		goto out_free_irq;
399
400	jrp->outring = dma_alloc_coherent(dev, sizeof(struct jr_outentry) *
401					  JOBR_DEPTH, &outbusaddr, GFP_KERNEL);
402	if (!jrp->outring)
403		goto out_free_inpring;
404
405	jrp->entinfo = kzalloc(sizeof(struct caam_jrentry_info) * JOBR_DEPTH,
406			       GFP_KERNEL);
407	if (!jrp->entinfo)
408		goto out_free_outring;
409
410	for (i = 0; i < JOBR_DEPTH; i++)
411		jrp->entinfo[i].desc_addr_dma = !0;
412
413	/* Setup rings */
414	jrp->inp_ring_write_index = 0;
415	jrp->out_ring_read_index = 0;
416	jrp->head = 0;
417	jrp->tail = 0;
418
419	wr_reg64(&jrp->rregs->inpring_base, inpbusaddr);
420	wr_reg64(&jrp->rregs->outring_base, outbusaddr);
421	wr_reg32(&jrp->rregs->inpring_size, JOBR_DEPTH);
422	wr_reg32(&jrp->rregs->outring_size, JOBR_DEPTH);
423
424	jrp->ringsize = JOBR_DEPTH;
425
426	spin_lock_init(&jrp->inplock);
427	spin_lock_init(&jrp->outlock);
428
429	/* Select interrupt coalescing parameters */
430	setbits32(&jrp->rregs->rconfig_lo, JOBR_INTC |
431		  (JOBR_INTC_COUNT_THLD << JRCFG_ICDCT_SHIFT) |
432		  (JOBR_INTC_TIME_THLD << JRCFG_ICTT_SHIFT));
433
434	return 0;
435
436out_free_outring:
437	dma_free_coherent(dev, sizeof(struct jr_outentry) * JOBR_DEPTH,
438			  jrp->outring, outbusaddr);
439out_free_inpring:
440	dma_free_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
441			  jrp->inpring, inpbusaddr);
442	dev_err(dev, "can't allocate job rings for %d\n", jrp->ridx);
443out_free_irq:
444	free_irq(jrp->irq, dev);
445out_kill_deq:
446	tasklet_kill(&jrp->irqtask);
447	return error;
448}
449
450
451/*
452 * Probe routine for each detected JobR subsystem.
453 */
454static int caam_jr_probe(struct platform_device *pdev)
455{
456	struct device *jrdev;
457	struct device_node *nprop;
458	struct caam_job_ring __iomem *ctrl;
459	struct caam_drv_private_jr *jrpriv;
460	static int total_jobrs;
461	int error;
462
463	jrdev = &pdev->dev;
464	jrpriv = devm_kmalloc(jrdev, sizeof(struct caam_drv_private_jr),
465			      GFP_KERNEL);
466	if (!jrpriv)
467		return -ENOMEM;
468
469	dev_set_drvdata(jrdev, jrpriv);
470
471	/* save ring identity relative to detection */
472	jrpriv->ridx = total_jobrs++;
473
474	nprop = pdev->dev.of_node;
475	/* Get configuration properties from device tree */
476	/* First, get register page */
477	ctrl = of_iomap(nprop, 0);
478	if (!ctrl) {
479		dev_err(jrdev, "of_iomap() failed\n");
480		return -ENOMEM;
481	}
482
483	jrpriv->rregs = (struct caam_job_ring __force *)ctrl;
484
485	if (sizeof(dma_addr_t) == sizeof(u64))
486		if (of_device_is_compatible(nprop, "fsl,sec-v5.0-job-ring"))
487			dma_set_mask_and_coherent(jrdev, DMA_BIT_MASK(40));
488		else
489			dma_set_mask_and_coherent(jrdev, DMA_BIT_MASK(36));
490	else
491		dma_set_mask_and_coherent(jrdev, DMA_BIT_MASK(32));
492
493	/* Identify the interrupt */
494	jrpriv->irq = irq_of_parse_and_map(nprop, 0);
495
496	/* Now do the platform independent part */
497	error = caam_jr_init(jrdev); /* now turn on hardware */
498	if (error) {
499		irq_dispose_mapping(jrpriv->irq);
500		return error;
501	}
502
503	jrpriv->dev = jrdev;
504	spin_lock(&driver_data.jr_alloc_lock);
505	list_add_tail(&jrpriv->list_node, &driver_data.jr_list);
506	spin_unlock(&driver_data.jr_alloc_lock);
507
508	atomic_set(&jrpriv->tfm_count, 0);
509
510	return 0;
511}
512
513static struct of_device_id caam_jr_match[] = {
514	{
515		.compatible = "fsl,sec-v4.0-job-ring",
516	},
517	{
518		.compatible = "fsl,sec4.0-job-ring",
519	},
520	{},
521};
522MODULE_DEVICE_TABLE(of, caam_jr_match);
523
524static struct platform_driver caam_jr_driver = {
525	.driver = {
526		.name = "caam_jr",
527		.of_match_table = caam_jr_match,
528	},
529	.probe       = caam_jr_probe,
530	.remove      = caam_jr_remove,
531};
532
533static int __init jr_driver_init(void)
534{
535	spin_lock_init(&driver_data.jr_alloc_lock);
536	INIT_LIST_HEAD(&driver_data.jr_list);
537	return platform_driver_register(&caam_jr_driver);
538}
539
540static void __exit jr_driver_exit(void)
541{
542	platform_driver_unregister(&caam_jr_driver);
543}
544
545module_init(jr_driver_init);
546module_exit(jr_driver_exit);
547
548MODULE_LICENSE("GPL");
549MODULE_DESCRIPTION("FSL CAAM JR request backend");
550MODULE_AUTHOR("Freescale Semiconductor - NMG/STC");
551