xref: /openbmc/linux/drivers/crypto/caam/jr.c (revision 5bd8e16d)
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_enqueue() - Enqueue a job descriptor head. Returns 0 if OK,
130  * -EBUSY if the queue is full, -EIO if it cannot map the caller's
131  * descriptor.
132  * @dev:  device of the job ring to be used. This device should have
133  *        been assigned prior by caam_jr_register().
134  * @desc: points to a job descriptor that execute our request. All
135  *        descriptors (and all referenced data) must be in a DMAable
136  *        region, and all data references must be physical addresses
137  *        accessible to CAAM (i.e. within a PAMU window granted
138  *        to it).
139  * @cbk:  pointer to a callback function to be invoked upon completion
140  *        of this request. This has the form:
141  *        callback(struct device *dev, u32 *desc, u32 stat, void *arg)
142  *        where:
143  *        @dev:    contains the job ring device that processed this
144  *                 response.
145  *        @desc:   descriptor that initiated the request, same as
146  *                 "desc" being argued to caam_jr_enqueue().
147  *        @status: untranslated status received from CAAM. See the
148  *                 reference manual for a detailed description of
149  *                 error meaning, or see the JRSTA definitions in the
150  *                 register header file
151  *        @areq:   optional pointer to an argument passed with the
152  *                 original request
153  * @areq: optional pointer to a user argument for use at callback
154  *        time.
155  **/
156 int caam_jr_enqueue(struct device *dev, u32 *desc,
157 		    void (*cbk)(struct device *dev, u32 *desc,
158 				u32 status, void *areq),
159 		    void *areq)
160 {
161 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
162 	struct caam_jrentry_info *head_entry;
163 	int head, tail, desc_size;
164 	dma_addr_t desc_dma;
165 
166 	desc_size = (*desc & HDR_JD_LENGTH_MASK) * sizeof(u32);
167 	desc_dma = dma_map_single(dev, desc, desc_size, DMA_TO_DEVICE);
168 	if (dma_mapping_error(dev, desc_dma)) {
169 		dev_err(dev, "caam_jr_enqueue(): can't map jobdesc\n");
170 		return -EIO;
171 	}
172 
173 	spin_lock_bh(&jrp->inplock);
174 
175 	head = jrp->head;
176 	tail = ACCESS_ONCE(jrp->tail);
177 
178 	if (!rd_reg32(&jrp->rregs->inpring_avail) ||
179 	    CIRC_SPACE(head, tail, JOBR_DEPTH) <= 0) {
180 		spin_unlock_bh(&jrp->inplock);
181 		dma_unmap_single(dev, desc_dma, desc_size, DMA_TO_DEVICE);
182 		return -EBUSY;
183 	}
184 
185 	head_entry = &jrp->entinfo[head];
186 	head_entry->desc_addr_virt = desc;
187 	head_entry->desc_size = desc_size;
188 	head_entry->callbk = (void *)cbk;
189 	head_entry->cbkarg = areq;
190 	head_entry->desc_addr_dma = desc_dma;
191 
192 	jrp->inpring[jrp->inp_ring_write_index] = desc_dma;
193 
194 	smp_wmb();
195 
196 	jrp->inp_ring_write_index = (jrp->inp_ring_write_index + 1) &
197 				    (JOBR_DEPTH - 1);
198 	jrp->head = (head + 1) & (JOBR_DEPTH - 1);
199 
200 	wr_reg32(&jrp->rregs->inpring_jobadd, 1);
201 
202 	spin_unlock_bh(&jrp->inplock);
203 
204 	return 0;
205 }
206 EXPORT_SYMBOL(caam_jr_enqueue);
207 
208 static int caam_reset_hw_jr(struct device *dev)
209 {
210 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
211 	unsigned int timeout = 100000;
212 
213 	/*
214 	 * mask interrupts since we are going to poll
215 	 * for reset completion status
216 	 */
217 	setbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);
218 
219 	/* initiate flush (required prior to reset) */
220 	wr_reg32(&jrp->rregs->jrcommand, JRCR_RESET);
221 	while (((rd_reg32(&jrp->rregs->jrintstatus) & JRINT_ERR_HALT_MASK) ==
222 		JRINT_ERR_HALT_INPROGRESS) && --timeout)
223 		cpu_relax();
224 
225 	if ((rd_reg32(&jrp->rregs->jrintstatus) & JRINT_ERR_HALT_MASK) !=
226 	    JRINT_ERR_HALT_COMPLETE || timeout == 0) {
227 		dev_err(dev, "failed to flush job ring %d\n", jrp->ridx);
228 		return -EIO;
229 	}
230 
231 	/* initiate reset */
232 	timeout = 100000;
233 	wr_reg32(&jrp->rregs->jrcommand, JRCR_RESET);
234 	while ((rd_reg32(&jrp->rregs->jrcommand) & JRCR_RESET) && --timeout)
235 		cpu_relax();
236 
237 	if (timeout == 0) {
238 		dev_err(dev, "failed to reset job ring %d\n", jrp->ridx);
239 		return -EIO;
240 	}
241 
242 	/* unmask interrupts */
243 	clrbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);
244 
245 	return 0;
246 }
247 
248 /*
249  * Init JobR independent of platform property detection
250  */
251 static int caam_jr_init(struct device *dev)
252 {
253 	struct caam_drv_private_jr *jrp;
254 	dma_addr_t inpbusaddr, outbusaddr;
255 	int i, error;
256 
257 	jrp = dev_get_drvdata(dev);
258 
259 	tasklet_init(&jrp->irqtask, caam_jr_dequeue, (unsigned long)dev);
260 
261 	/* Connect job ring interrupt handler. */
262 	error = request_irq(jrp->irq, caam_jr_interrupt, IRQF_SHARED,
263 			    "caam-jobr", dev);
264 	if (error) {
265 		dev_err(dev, "can't connect JobR %d interrupt (%d)\n",
266 			jrp->ridx, jrp->irq);
267 		irq_dispose_mapping(jrp->irq);
268 		jrp->irq = 0;
269 		return -EINVAL;
270 	}
271 
272 	error = caam_reset_hw_jr(dev);
273 	if (error)
274 		return error;
275 
276 	jrp->inpring = dma_alloc_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
277 					  &inpbusaddr, GFP_KERNEL);
278 
279 	jrp->outring = dma_alloc_coherent(dev, sizeof(struct jr_outentry) *
280 					  JOBR_DEPTH, &outbusaddr, GFP_KERNEL);
281 
282 	jrp->entinfo = kzalloc(sizeof(struct caam_jrentry_info) * JOBR_DEPTH,
283 			       GFP_KERNEL);
284 
285 	if ((jrp->inpring == NULL) || (jrp->outring == NULL) ||
286 	    (jrp->entinfo == NULL)) {
287 		dev_err(dev, "can't allocate job rings for %d\n",
288 			jrp->ridx);
289 		return -ENOMEM;
290 	}
291 
292 	for (i = 0; i < JOBR_DEPTH; i++)
293 		jrp->entinfo[i].desc_addr_dma = !0;
294 
295 	/* Setup rings */
296 	jrp->inp_ring_write_index = 0;
297 	jrp->out_ring_read_index = 0;
298 	jrp->head = 0;
299 	jrp->tail = 0;
300 
301 	wr_reg64(&jrp->rregs->inpring_base, inpbusaddr);
302 	wr_reg64(&jrp->rregs->outring_base, outbusaddr);
303 	wr_reg32(&jrp->rregs->inpring_size, JOBR_DEPTH);
304 	wr_reg32(&jrp->rregs->outring_size, JOBR_DEPTH);
305 
306 	jrp->ringsize = JOBR_DEPTH;
307 
308 	spin_lock_init(&jrp->inplock);
309 	spin_lock_init(&jrp->outlock);
310 
311 	/* Select interrupt coalescing parameters */
312 	setbits32(&jrp->rregs->rconfig_lo, JOBR_INTC |
313 		  (JOBR_INTC_COUNT_THLD << JRCFG_ICDCT_SHIFT) |
314 		  (JOBR_INTC_TIME_THLD << JRCFG_ICTT_SHIFT));
315 
316 	return 0;
317 }
318 
319 /*
320  * Shutdown JobR independent of platform property code
321  */
322 int caam_jr_shutdown(struct device *dev)
323 {
324 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
325 	dma_addr_t inpbusaddr, outbusaddr;
326 	int ret;
327 
328 	ret = caam_reset_hw_jr(dev);
329 
330 	tasklet_kill(&jrp->irqtask);
331 
332 	/* Release interrupt */
333 	free_irq(jrp->irq, dev);
334 
335 	/* Free rings */
336 	inpbusaddr = rd_reg64(&jrp->rregs->inpring_base);
337 	outbusaddr = rd_reg64(&jrp->rregs->outring_base);
338 	dma_free_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
339 			  jrp->inpring, inpbusaddr);
340 	dma_free_coherent(dev, sizeof(struct jr_outentry) * JOBR_DEPTH,
341 			  jrp->outring, outbusaddr);
342 	kfree(jrp->entinfo);
343 	of_device_unregister(jrp->jr_pdev);
344 
345 	return ret;
346 }
347 
348 /*
349  * Probe routine for each detected JobR subsystem. It assumes that
350  * property detection was picked up externally.
351  */
352 int caam_jr_probe(struct platform_device *pdev, struct device_node *np,
353 		  int ring)
354 {
355 	struct device *ctrldev, *jrdev;
356 	struct platform_device *jr_pdev;
357 	struct caam_drv_private *ctrlpriv;
358 	struct caam_drv_private_jr *jrpriv;
359 	u32 *jroffset;
360 	int error;
361 
362 	ctrldev = &pdev->dev;
363 	ctrlpriv = dev_get_drvdata(ctrldev);
364 
365 	jrpriv = kmalloc(sizeof(struct caam_drv_private_jr),
366 			 GFP_KERNEL);
367 	if (jrpriv == NULL) {
368 		dev_err(ctrldev, "can't alloc private mem for job ring %d\n",
369 			ring);
370 		return -ENOMEM;
371 	}
372 	jrpriv->parentdev = ctrldev; /* point back to parent */
373 	jrpriv->ridx = ring; /* save ring identity relative to detection */
374 
375 	/*
376 	 * Derive a pointer to the detected JobRs regs
377 	 * Driver has already iomapped the entire space, we just
378 	 * need to add in the offset to this JobR. Don't know if I
379 	 * like this long-term, but it'll run
380 	 */
381 	jroffset = (u32 *)of_get_property(np, "reg", NULL);
382 	jrpriv->rregs = (struct caam_job_ring __iomem *)((void *)ctrlpriv->ctrl
383 							 + *jroffset);
384 
385 	/* Build a local dev for each detected queue */
386 	jr_pdev = of_platform_device_create(np, NULL, ctrldev);
387 	if (jr_pdev == NULL) {
388 		kfree(jrpriv);
389 		return -EINVAL;
390 	}
391 
392 	jrpriv->jr_pdev = jr_pdev;
393 	jrdev = &jr_pdev->dev;
394 	dev_set_drvdata(jrdev, jrpriv);
395 	ctrlpriv->jrdev[ring] = jrdev;
396 
397 	if (sizeof(dma_addr_t) == sizeof(u64))
398 		if (of_device_is_compatible(np, "fsl,sec-v5.0-job-ring"))
399 			dma_set_mask(jrdev, DMA_BIT_MASK(40));
400 		else
401 			dma_set_mask(jrdev, DMA_BIT_MASK(36));
402 	else
403 		dma_set_mask(jrdev, DMA_BIT_MASK(32));
404 
405 	/* Identify the interrupt */
406 	jrpriv->irq = of_irq_to_resource(np, 0, NULL);
407 
408 	/* Now do the platform independent part */
409 	error = caam_jr_init(jrdev); /* now turn on hardware */
410 	if (error) {
411 		of_device_unregister(jr_pdev);
412 		kfree(jrpriv);
413 		return error;
414 	}
415 
416 	return error;
417 }
418