xref: /openbmc/linux/drivers/dma/mv_xor_v2.c (revision 9ac17575)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2015-2016 Marvell International Ltd.
4 
5  */
6 
7 #include <linux/clk.h>
8 #include <linux/dma-mapping.h>
9 #include <linux/interrupt.h>
10 #include <linux/io.h>
11 #include <linux/module.h>
12 #include <linux/msi.h>
13 #include <linux/of.h>
14 #include <linux/of_irq.h>
15 #include <linux/platform_device.h>
16 #include <linux/spinlock.h>
17 
18 #include "dmaengine.h"
19 
20 /* DMA Engine Registers */
21 #define MV_XOR_V2_DMA_DESQ_BALR_OFF			0x000
22 #define MV_XOR_V2_DMA_DESQ_BAHR_OFF			0x004
23 #define MV_XOR_V2_DMA_DESQ_SIZE_OFF			0x008
24 #define MV_XOR_V2_DMA_DESQ_DONE_OFF			0x00C
25 #define   MV_XOR_V2_DMA_DESQ_DONE_PENDING_MASK		0x7FFF
26 #define   MV_XOR_V2_DMA_DESQ_DONE_PENDING_SHIFT		0
27 #define   MV_XOR_V2_DMA_DESQ_DONE_READ_PTR_MASK		0x1FFF
28 #define   MV_XOR_V2_DMA_DESQ_DONE_READ_PTR_SHIFT	16
29 #define MV_XOR_V2_DMA_DESQ_ARATTR_OFF			0x010
30 #define   MV_XOR_V2_DMA_DESQ_ATTR_CACHE_MASK		0x3F3F
31 #define   MV_XOR_V2_DMA_DESQ_ATTR_OUTER_SHAREABLE	0x202
32 #define   MV_XOR_V2_DMA_DESQ_ATTR_CACHEABLE		0x3C3C
33 #define MV_XOR_V2_DMA_IMSG_CDAT_OFF			0x014
34 #define MV_XOR_V2_DMA_IMSG_THRD_OFF			0x018
35 #define   MV_XOR_V2_DMA_IMSG_THRD_MASK			0x7FFF
36 #define   MV_XOR_V2_DMA_IMSG_TIMER_EN			BIT(18)
37 #define MV_XOR_V2_DMA_DESQ_AWATTR_OFF			0x01C
38   /* Same flags as MV_XOR_V2_DMA_DESQ_ARATTR_OFF */
39 #define MV_XOR_V2_DMA_DESQ_ALLOC_OFF			0x04C
40 #define   MV_XOR_V2_DMA_DESQ_ALLOC_WRPTR_MASK		0xFFFF
41 #define   MV_XOR_V2_DMA_DESQ_ALLOC_WRPTR_SHIFT		16
42 #define MV_XOR_V2_DMA_IMSG_BALR_OFF			0x050
43 #define MV_XOR_V2_DMA_IMSG_BAHR_OFF			0x054
44 #define MV_XOR_V2_DMA_DESQ_CTRL_OFF			0x100
45 #define	  MV_XOR_V2_DMA_DESQ_CTRL_32B			1
46 #define   MV_XOR_V2_DMA_DESQ_CTRL_128B			7
47 #define MV_XOR_V2_DMA_DESQ_STOP_OFF			0x800
48 #define MV_XOR_V2_DMA_DESQ_DEALLOC_OFF			0x804
49 #define MV_XOR_V2_DMA_DESQ_ADD_OFF			0x808
50 #define MV_XOR_V2_DMA_IMSG_TMOT				0x810
51 #define   MV_XOR_V2_DMA_IMSG_TIMER_THRD_MASK		0x1FFF
52 
53 /* XOR Global registers */
54 #define MV_XOR_V2_GLOB_BW_CTRL				0x4
55 #define   MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_RD_SHIFT	0
56 #define   MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_RD_VAL	64
57 #define   MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_WR_SHIFT	8
58 #define   MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_WR_VAL	8
59 #define   MV_XOR_V2_GLOB_BW_CTRL_RD_BURST_LEN_SHIFT	12
60 #define   MV_XOR_V2_GLOB_BW_CTRL_RD_BURST_LEN_VAL	4
61 #define   MV_XOR_V2_GLOB_BW_CTRL_WR_BURST_LEN_SHIFT	16
62 #define	  MV_XOR_V2_GLOB_BW_CTRL_WR_BURST_LEN_VAL	4
63 #define MV_XOR_V2_GLOB_PAUSE				0x014
64 #define   MV_XOR_V2_GLOB_PAUSE_AXI_TIME_DIS_VAL		0x8
65 #define MV_XOR_V2_GLOB_SYS_INT_CAUSE			0x200
66 #define MV_XOR_V2_GLOB_SYS_INT_MASK			0x204
67 #define MV_XOR_V2_GLOB_MEM_INT_CAUSE			0x220
68 #define MV_XOR_V2_GLOB_MEM_INT_MASK			0x224
69 
70 #define MV_XOR_V2_MIN_DESC_SIZE				32
71 #define MV_XOR_V2_EXT_DESC_SIZE				128
72 
73 #define MV_XOR_V2_DESC_RESERVED_SIZE			12
74 #define MV_XOR_V2_DESC_BUFF_D_ADDR_SIZE			12
75 
76 #define MV_XOR_V2_CMD_LINE_NUM_MAX_D_BUF		8
77 
78 /*
79  * Descriptors queue size. With 32 bytes descriptors, up to 2^14
80  * descriptors are allowed, with 128 bytes descriptors, up to 2^12
81  * descriptors are allowed. This driver uses 128 bytes descriptors,
82  * but experimentation has shown that a set of 1024 descriptors is
83  * sufficient to reach a good level of performance.
84  */
85 #define MV_XOR_V2_DESC_NUM				1024
86 
87 /*
88  * Threshold values for descriptors and timeout, determined by
89  * experimentation as giving a good level of performance.
90  */
91 #define MV_XOR_V2_DONE_IMSG_THRD  0x14
92 #define MV_XOR_V2_TIMER_THRD      0xB0
93 
94 /**
95  * struct mv_xor_v2_descriptor - DMA HW descriptor
96  * @desc_id: used by S/W and is not affected by H/W.
97  * @flags: error and status flags
98  * @crc32_result: CRC32 calculation result
99  * @desc_ctrl: operation mode and control flags
100  * @buff_size: amount of bytes to be processed
101  * @fill_pattern_src_addr: Fill-Pattern or Source-Address and
102  * AW-Attributes
103  * @data_buff_addr: Source (and might be RAID6 destination)
104  * addresses of data buffers in RAID5 and RAID6
105  * @reserved: reserved
106  */
107 struct mv_xor_v2_descriptor {
108 	u16 desc_id;
109 	u16 flags;
110 	u32 crc32_result;
111 	u32 desc_ctrl;
112 
113 	/* Definitions for desc_ctrl */
114 #define DESC_NUM_ACTIVE_D_BUF_SHIFT	22
115 #define DESC_OP_MODE_SHIFT		28
116 #define DESC_OP_MODE_NOP		0	/* Idle operation */
117 #define DESC_OP_MODE_MEMCPY		1	/* Pure-DMA operation */
118 #define DESC_OP_MODE_MEMSET		2	/* Mem-Fill operation */
119 #define DESC_OP_MODE_MEMINIT		3	/* Mem-Init operation */
120 #define DESC_OP_MODE_MEM_COMPARE	4	/* Mem-Compare operation */
121 #define DESC_OP_MODE_CRC32		5	/* CRC32 calculation */
122 #define DESC_OP_MODE_XOR		6	/* RAID5 (XOR) operation */
123 #define DESC_OP_MODE_RAID6		7	/* RAID6 P&Q-generation */
124 #define DESC_OP_MODE_RAID6_REC		8	/* RAID6 Recovery */
125 #define DESC_Q_BUFFER_ENABLE		BIT(16)
126 #define DESC_P_BUFFER_ENABLE		BIT(17)
127 #define DESC_IOD			BIT(27)
128 
129 	u32 buff_size;
130 	u32 fill_pattern_src_addr[4];
131 	u32 data_buff_addr[MV_XOR_V2_DESC_BUFF_D_ADDR_SIZE];
132 	u32 reserved[MV_XOR_V2_DESC_RESERVED_SIZE];
133 };
134 
135 /**
136  * struct mv_xor_v2_device - implements a xor device
137  * @lock: lock for the engine
138  * @dma_base: memory mapped DMA register base
139  * @glob_base: memory mapped global register base
140  * @irq_tasklet:
141  * @free_sw_desc: linked list of free SW descriptors
142  * @dmadev: dma device
143  * @dmachan: dma channel
144  * @hw_desq: HW descriptors queue
145  * @hw_desq_virt: virtual address of DESCQ
146  * @sw_desq: SW descriptors queue
147  * @desc_size: HW descriptor size
148  * @npendings: number of pending descriptors (for which tx_submit has
149  * been called, but not yet issue_pending)
150  */
151 struct mv_xor_v2_device {
152 	spinlock_t lock;
153 	void __iomem *dma_base;
154 	void __iomem *glob_base;
155 	struct clk *clk;
156 	struct clk *reg_clk;
157 	struct tasklet_struct irq_tasklet;
158 	struct list_head free_sw_desc;
159 	struct dma_device dmadev;
160 	struct dma_chan	dmachan;
161 	dma_addr_t hw_desq;
162 	struct mv_xor_v2_descriptor *hw_desq_virt;
163 	struct mv_xor_v2_sw_desc *sw_desq;
164 	int desc_size;
165 	unsigned int npendings;
166 	unsigned int hw_queue_idx;
167 	struct msi_desc *msi_desc;
168 };
169 
170 /**
171  * struct mv_xor_v2_sw_desc - implements a xor SW descriptor
172  * @idx: descriptor index
173  * @async_tx: support for the async_tx api
174  * @hw_desc: assosiated HW descriptor
175  * @free_list: node of the free SW descriprots list
176 */
177 struct mv_xor_v2_sw_desc {
178 	int idx;
179 	struct dma_async_tx_descriptor async_tx;
180 	struct mv_xor_v2_descriptor hw_desc;
181 	struct list_head free_list;
182 };
183 
184 /*
185  * Fill the data buffers to a HW descriptor
186  */
187 static void mv_xor_v2_set_data_buffers(struct mv_xor_v2_device *xor_dev,
188 					struct mv_xor_v2_descriptor *desc,
189 					dma_addr_t src, int index)
190 {
191 	int arr_index = ((index >> 1) * 3);
192 
193 	/*
194 	 * Fill the buffer's addresses to the descriptor.
195 	 *
196 	 * The format of the buffers address for 2 sequential buffers
197 	 * X and X + 1:
198 	 *
199 	 *  First word:  Buffer-DX-Address-Low[31:0]
200 	 *  Second word: Buffer-DX+1-Address-Low[31:0]
201 	 *  Third word:  DX+1-Buffer-Address-High[47:32] [31:16]
202 	 *		 DX-Buffer-Address-High[47:32] [15:0]
203 	 */
204 	if ((index & 0x1) == 0) {
205 		desc->data_buff_addr[arr_index] = lower_32_bits(src);
206 
207 		desc->data_buff_addr[arr_index + 2] &= ~0xFFFF;
208 		desc->data_buff_addr[arr_index + 2] |=
209 			upper_32_bits(src) & 0xFFFF;
210 	} else {
211 		desc->data_buff_addr[arr_index + 1] =
212 			lower_32_bits(src);
213 
214 		desc->data_buff_addr[arr_index + 2] &= ~0xFFFF0000;
215 		desc->data_buff_addr[arr_index + 2] |=
216 			(upper_32_bits(src) & 0xFFFF) << 16;
217 	}
218 }
219 
220 /*
221  * notify the engine of new descriptors, and update the available index.
222  */
223 static void mv_xor_v2_add_desc_to_desq(struct mv_xor_v2_device *xor_dev,
224 				       int num_of_desc)
225 {
226 	/* write the number of new descriptors in the DESQ. */
227 	writel(num_of_desc, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_ADD_OFF);
228 }
229 
230 /*
231  * free HW descriptors
232  */
233 static void mv_xor_v2_free_desc_from_desq(struct mv_xor_v2_device *xor_dev,
234 					  int num_of_desc)
235 {
236 	/* write the number of new descriptors in the DESQ. */
237 	writel(num_of_desc, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_DEALLOC_OFF);
238 }
239 
240 /*
241  * Set descriptor size
242  * Return the HW descriptor size in bytes
243  */
244 static int mv_xor_v2_set_desc_size(struct mv_xor_v2_device *xor_dev)
245 {
246 	writel(MV_XOR_V2_DMA_DESQ_CTRL_128B,
247 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_CTRL_OFF);
248 
249 	return MV_XOR_V2_EXT_DESC_SIZE;
250 }
251 
252 /*
253  * Set the IMSG threshold
254  */
255 static inline
256 void mv_xor_v2_enable_imsg_thrd(struct mv_xor_v2_device *xor_dev)
257 {
258 	u32 reg;
259 
260 	/* Configure threshold of number of descriptors, and enable timer */
261 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
262 	reg &= ~MV_XOR_V2_DMA_IMSG_THRD_MASK;
263 	reg |= MV_XOR_V2_DONE_IMSG_THRD;
264 	reg |= MV_XOR_V2_DMA_IMSG_TIMER_EN;
265 	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
266 
267 	/* Configure Timer Threshold */
268 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_TMOT);
269 	reg &= ~MV_XOR_V2_DMA_IMSG_TIMER_THRD_MASK;
270 	reg |= MV_XOR_V2_TIMER_THRD;
271 	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_TMOT);
272 }
273 
274 static irqreturn_t mv_xor_v2_interrupt_handler(int irq, void *data)
275 {
276 	struct mv_xor_v2_device *xor_dev = data;
277 	unsigned int ndescs;
278 	u32 reg;
279 
280 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_DONE_OFF);
281 
282 	ndescs = ((reg >> MV_XOR_V2_DMA_DESQ_DONE_PENDING_SHIFT) &
283 		  MV_XOR_V2_DMA_DESQ_DONE_PENDING_MASK);
284 
285 	/* No descriptors to process */
286 	if (!ndescs)
287 		return IRQ_NONE;
288 
289 	/* schedule a tasklet to handle descriptors callbacks */
290 	tasklet_schedule(&xor_dev->irq_tasklet);
291 
292 	return IRQ_HANDLED;
293 }
294 
295 /*
296  * submit a descriptor to the DMA engine
297  */
298 static dma_cookie_t
299 mv_xor_v2_tx_submit(struct dma_async_tx_descriptor *tx)
300 {
301 	void *dest_hw_desc;
302 	dma_cookie_t cookie;
303 	struct mv_xor_v2_sw_desc *sw_desc =
304 		container_of(tx, struct mv_xor_v2_sw_desc, async_tx);
305 	struct mv_xor_v2_device *xor_dev =
306 		container_of(tx->chan, struct mv_xor_v2_device, dmachan);
307 
308 	dev_dbg(xor_dev->dmadev.dev,
309 		"%s sw_desc %p: async_tx %p\n",
310 		__func__, sw_desc, &sw_desc->async_tx);
311 
312 	/* assign coookie */
313 	spin_lock_bh(&xor_dev->lock);
314 	cookie = dma_cookie_assign(tx);
315 
316 	/* copy the HW descriptor from the SW descriptor to the DESQ */
317 	dest_hw_desc = xor_dev->hw_desq_virt + xor_dev->hw_queue_idx;
318 
319 	memcpy(dest_hw_desc, &sw_desc->hw_desc, xor_dev->desc_size);
320 
321 	xor_dev->npendings++;
322 	xor_dev->hw_queue_idx++;
323 	if (xor_dev->hw_queue_idx >= MV_XOR_V2_DESC_NUM)
324 		xor_dev->hw_queue_idx = 0;
325 
326 	spin_unlock_bh(&xor_dev->lock);
327 
328 	return cookie;
329 }
330 
331 /*
332  * Prepare a SW descriptor
333  */
334 static struct mv_xor_v2_sw_desc	*
335 mv_xor_v2_prep_sw_desc(struct mv_xor_v2_device *xor_dev)
336 {
337 	struct mv_xor_v2_sw_desc *sw_desc;
338 	bool found = false;
339 
340 	/* Lock the channel */
341 	spin_lock_bh(&xor_dev->lock);
342 
343 	if (list_empty(&xor_dev->free_sw_desc)) {
344 		spin_unlock_bh(&xor_dev->lock);
345 		/* schedule tasklet to free some descriptors */
346 		tasklet_schedule(&xor_dev->irq_tasklet);
347 		return NULL;
348 	}
349 
350 	list_for_each_entry(sw_desc, &xor_dev->free_sw_desc, free_list) {
351 		if (async_tx_test_ack(&sw_desc->async_tx)) {
352 			found = true;
353 			break;
354 		}
355 	}
356 
357 	if (!found) {
358 		spin_unlock_bh(&xor_dev->lock);
359 		return NULL;
360 	}
361 
362 	list_del(&sw_desc->free_list);
363 
364 	/* Release the channel */
365 	spin_unlock_bh(&xor_dev->lock);
366 
367 	return sw_desc;
368 }
369 
370 /*
371  * Prepare a HW descriptor for a memcpy operation
372  */
373 static struct dma_async_tx_descriptor *
374 mv_xor_v2_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest,
375 			  dma_addr_t src, size_t len, unsigned long flags)
376 {
377 	struct mv_xor_v2_sw_desc *sw_desc;
378 	struct mv_xor_v2_descriptor *hw_descriptor;
379 	struct mv_xor_v2_device	*xor_dev;
380 
381 	xor_dev = container_of(chan, struct mv_xor_v2_device, dmachan);
382 
383 	dev_dbg(xor_dev->dmadev.dev,
384 		"%s len: %zu src %pad dest %pad flags: %ld\n",
385 		__func__, len, &src, &dest, flags);
386 
387 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
388 	if (!sw_desc)
389 		return NULL;
390 
391 	sw_desc->async_tx.flags = flags;
392 
393 	/* set the HW descriptor */
394 	hw_descriptor = &sw_desc->hw_desc;
395 
396 	/* save the SW descriptor ID to restore when operation is done */
397 	hw_descriptor->desc_id = sw_desc->idx;
398 
399 	/* Set the MEMCPY control word */
400 	hw_descriptor->desc_ctrl =
401 		DESC_OP_MODE_MEMCPY << DESC_OP_MODE_SHIFT;
402 
403 	if (flags & DMA_PREP_INTERRUPT)
404 		hw_descriptor->desc_ctrl |= DESC_IOD;
405 
406 	/* Set source address */
407 	hw_descriptor->fill_pattern_src_addr[0] = lower_32_bits(src);
408 	hw_descriptor->fill_pattern_src_addr[1] =
409 		upper_32_bits(src) & 0xFFFF;
410 
411 	/* Set Destination address */
412 	hw_descriptor->fill_pattern_src_addr[2] = lower_32_bits(dest);
413 	hw_descriptor->fill_pattern_src_addr[3] =
414 		upper_32_bits(dest) & 0xFFFF;
415 
416 	/* Set buffers size */
417 	hw_descriptor->buff_size = len;
418 
419 	/* return the async tx descriptor */
420 	return &sw_desc->async_tx;
421 }
422 
423 /*
424  * Prepare a HW descriptor for a XOR operation
425  */
426 static struct dma_async_tx_descriptor *
427 mv_xor_v2_prep_dma_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
428 		       unsigned int src_cnt, size_t len, unsigned long flags)
429 {
430 	struct mv_xor_v2_sw_desc *sw_desc;
431 	struct mv_xor_v2_descriptor *hw_descriptor;
432 	struct mv_xor_v2_device	*xor_dev =
433 		container_of(chan, struct mv_xor_v2_device, dmachan);
434 	int i;
435 
436 	if (src_cnt > MV_XOR_V2_CMD_LINE_NUM_MAX_D_BUF || src_cnt < 1)
437 		return NULL;
438 
439 	dev_dbg(xor_dev->dmadev.dev,
440 		"%s src_cnt: %d len: %zu dest %pad flags: %ld\n",
441 		__func__, src_cnt, len, &dest, flags);
442 
443 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
444 	if (!sw_desc)
445 		return NULL;
446 
447 	sw_desc->async_tx.flags = flags;
448 
449 	/* set the HW descriptor */
450 	hw_descriptor = &sw_desc->hw_desc;
451 
452 	/* save the SW descriptor ID to restore when operation is done */
453 	hw_descriptor->desc_id = sw_desc->idx;
454 
455 	/* Set the XOR control word */
456 	hw_descriptor->desc_ctrl =
457 		DESC_OP_MODE_XOR << DESC_OP_MODE_SHIFT;
458 	hw_descriptor->desc_ctrl |= DESC_P_BUFFER_ENABLE;
459 
460 	if (flags & DMA_PREP_INTERRUPT)
461 		hw_descriptor->desc_ctrl |= DESC_IOD;
462 
463 	/* Set the data buffers */
464 	for (i = 0; i < src_cnt; i++)
465 		mv_xor_v2_set_data_buffers(xor_dev, hw_descriptor, src[i], i);
466 
467 	hw_descriptor->desc_ctrl |=
468 		src_cnt << DESC_NUM_ACTIVE_D_BUF_SHIFT;
469 
470 	/* Set Destination address */
471 	hw_descriptor->fill_pattern_src_addr[2] = lower_32_bits(dest);
472 	hw_descriptor->fill_pattern_src_addr[3] =
473 		upper_32_bits(dest) & 0xFFFF;
474 
475 	/* Set buffers size */
476 	hw_descriptor->buff_size = len;
477 
478 	/* return the async tx descriptor */
479 	return &sw_desc->async_tx;
480 }
481 
482 /*
483  * Prepare a HW descriptor for interrupt operation.
484  */
485 static struct dma_async_tx_descriptor *
486 mv_xor_v2_prep_dma_interrupt(struct dma_chan *chan, unsigned long flags)
487 {
488 	struct mv_xor_v2_sw_desc *sw_desc;
489 	struct mv_xor_v2_descriptor *hw_descriptor;
490 	struct mv_xor_v2_device	*xor_dev =
491 		container_of(chan, struct mv_xor_v2_device, dmachan);
492 
493 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
494 	if (!sw_desc)
495 		return NULL;
496 
497 	/* set the HW descriptor */
498 	hw_descriptor = &sw_desc->hw_desc;
499 
500 	/* save the SW descriptor ID to restore when operation is done */
501 	hw_descriptor->desc_id = sw_desc->idx;
502 
503 	/* Set the INTERRUPT control word */
504 	hw_descriptor->desc_ctrl =
505 		DESC_OP_MODE_NOP << DESC_OP_MODE_SHIFT;
506 	hw_descriptor->desc_ctrl |= DESC_IOD;
507 
508 	/* return the async tx descriptor */
509 	return &sw_desc->async_tx;
510 }
511 
512 /*
513  * push pending transactions to hardware
514  */
515 static void mv_xor_v2_issue_pending(struct dma_chan *chan)
516 {
517 	struct mv_xor_v2_device *xor_dev =
518 		container_of(chan, struct mv_xor_v2_device, dmachan);
519 
520 	spin_lock_bh(&xor_dev->lock);
521 
522 	/*
523 	 * update the engine with the number of descriptors to
524 	 * process
525 	 */
526 	mv_xor_v2_add_desc_to_desq(xor_dev, xor_dev->npendings);
527 	xor_dev->npendings = 0;
528 
529 	spin_unlock_bh(&xor_dev->lock);
530 }
531 
532 static inline
533 int mv_xor_v2_get_pending_params(struct mv_xor_v2_device *xor_dev,
534 				 int *pending_ptr)
535 {
536 	u32 reg;
537 
538 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_DONE_OFF);
539 
540 	/* get the next pending descriptor index */
541 	*pending_ptr = ((reg >> MV_XOR_V2_DMA_DESQ_DONE_READ_PTR_SHIFT) &
542 			MV_XOR_V2_DMA_DESQ_DONE_READ_PTR_MASK);
543 
544 	/* get the number of descriptors pending handle */
545 	return ((reg >> MV_XOR_V2_DMA_DESQ_DONE_PENDING_SHIFT) &
546 		MV_XOR_V2_DMA_DESQ_DONE_PENDING_MASK);
547 }
548 
549 /*
550  * handle the descriptors after HW process
551  */
552 static void mv_xor_v2_tasklet(unsigned long data)
553 {
554 	struct mv_xor_v2_device *xor_dev = (struct mv_xor_v2_device *) data;
555 	int pending_ptr, num_of_pending, i;
556 	struct mv_xor_v2_sw_desc *next_pending_sw_desc = NULL;
557 
558 	dev_dbg(xor_dev->dmadev.dev, "%s %d\n", __func__, __LINE__);
559 
560 	/* get the pending descriptors parameters */
561 	num_of_pending = mv_xor_v2_get_pending_params(xor_dev, &pending_ptr);
562 
563 	/* loop over free descriptors */
564 	for (i = 0; i < num_of_pending; i++) {
565 		struct mv_xor_v2_descriptor *next_pending_hw_desc =
566 			xor_dev->hw_desq_virt + pending_ptr;
567 
568 		/* get the SW descriptor related to the HW descriptor */
569 		next_pending_sw_desc =
570 			&xor_dev->sw_desq[next_pending_hw_desc->desc_id];
571 
572 		/* call the callback */
573 		if (next_pending_sw_desc->async_tx.cookie > 0) {
574 			/*
575 			 * update the channel's completed cookie - no
576 			 * lock is required the IMSG threshold provide
577 			 * the locking
578 			 */
579 			dma_cookie_complete(&next_pending_sw_desc->async_tx);
580 
581 			dma_descriptor_unmap(&next_pending_sw_desc->async_tx);
582 			dmaengine_desc_get_callback_invoke(
583 					&next_pending_sw_desc->async_tx, NULL);
584 		}
585 
586 		dma_run_dependencies(&next_pending_sw_desc->async_tx);
587 
588 		/* Lock the channel */
589 		spin_lock_bh(&xor_dev->lock);
590 
591 		/* add the SW descriptor to the free descriptors list */
592 		list_add(&next_pending_sw_desc->free_list,
593 			 &xor_dev->free_sw_desc);
594 
595 		/* Release the channel */
596 		spin_unlock_bh(&xor_dev->lock);
597 
598 		/* increment the next descriptor */
599 		pending_ptr++;
600 		if (pending_ptr >= MV_XOR_V2_DESC_NUM)
601 			pending_ptr = 0;
602 	}
603 
604 	if (num_of_pending != 0) {
605 		/* free the descriptores */
606 		mv_xor_v2_free_desc_from_desq(xor_dev, num_of_pending);
607 	}
608 }
609 
610 /*
611  *	Set DMA Interrupt-message (IMSG) parameters
612  */
613 static void mv_xor_v2_set_msi_msg(struct msi_desc *desc, struct msi_msg *msg)
614 {
615 	struct mv_xor_v2_device *xor_dev = dev_get_drvdata(desc->dev);
616 
617 	writel(msg->address_lo,
618 	       xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_BALR_OFF);
619 	writel(msg->address_hi & 0xFFFF,
620 	       xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_BAHR_OFF);
621 	writel(msg->data,
622 	       xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_CDAT_OFF);
623 }
624 
625 static int mv_xor_v2_descq_init(struct mv_xor_v2_device *xor_dev)
626 {
627 	u32 reg;
628 
629 	/* write the DESQ size to the DMA engine */
630 	writel(MV_XOR_V2_DESC_NUM,
631 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_SIZE_OFF);
632 
633 	/* write the DESQ address to the DMA enngine*/
634 	writel(lower_32_bits(xor_dev->hw_desq),
635 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_BALR_OFF);
636 	writel(upper_32_bits(xor_dev->hw_desq),
637 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_BAHR_OFF);
638 
639 	/*
640 	 * This is a temporary solution, until we activate the
641 	 * SMMU. Set the attributes for reading & writing data buffers
642 	 * & descriptors to:
643 	 *
644 	 *  - OuterShareable - Snoops will be performed on CPU caches
645 	 *  - Enable cacheable - Bufferable, Modifiable, Other Allocate
646 	 *    and Allocate
647 	 */
648 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_ARATTR_OFF);
649 	reg &= ~MV_XOR_V2_DMA_DESQ_ATTR_CACHE_MASK;
650 	reg |= MV_XOR_V2_DMA_DESQ_ATTR_OUTER_SHAREABLE |
651 		MV_XOR_V2_DMA_DESQ_ATTR_CACHEABLE;
652 	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_ARATTR_OFF);
653 
654 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_AWATTR_OFF);
655 	reg &= ~MV_XOR_V2_DMA_DESQ_ATTR_CACHE_MASK;
656 	reg |= MV_XOR_V2_DMA_DESQ_ATTR_OUTER_SHAREABLE |
657 		MV_XOR_V2_DMA_DESQ_ATTR_CACHEABLE;
658 	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_AWATTR_OFF);
659 
660 	/* BW CTRL - set values to optimize the XOR performance:
661 	 *
662 	 *  - Set WrBurstLen & RdBurstLen - the unit will issue
663 	 *    maximum of 256B write/read transactions.
664 	 * -  Limit the number of outstanding write & read data
665 	 *    (OBB/IBB) requests to the maximal value.
666 	*/
667 	reg = ((MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_RD_VAL <<
668 		MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_RD_SHIFT) |
669 	       (MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_WR_VAL  <<
670 		MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_WR_SHIFT) |
671 	       (MV_XOR_V2_GLOB_BW_CTRL_RD_BURST_LEN_VAL <<
672 		MV_XOR_V2_GLOB_BW_CTRL_RD_BURST_LEN_SHIFT) |
673 	       (MV_XOR_V2_GLOB_BW_CTRL_WR_BURST_LEN_VAL <<
674 		MV_XOR_V2_GLOB_BW_CTRL_WR_BURST_LEN_SHIFT));
675 	writel(reg, xor_dev->glob_base + MV_XOR_V2_GLOB_BW_CTRL);
676 
677 	/* Disable the AXI timer feature */
678 	reg = readl(xor_dev->glob_base + MV_XOR_V2_GLOB_PAUSE);
679 	reg |= MV_XOR_V2_GLOB_PAUSE_AXI_TIME_DIS_VAL;
680 	writel(reg, xor_dev->glob_base + MV_XOR_V2_GLOB_PAUSE);
681 
682 	/* enable the DMA engine */
683 	writel(0, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_STOP_OFF);
684 
685 	return 0;
686 }
687 
688 static int mv_xor_v2_suspend(struct platform_device *dev, pm_message_t state)
689 {
690 	struct mv_xor_v2_device *xor_dev = platform_get_drvdata(dev);
691 
692 	/* Set this bit to disable to stop the XOR unit. */
693 	writel(0x1, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_STOP_OFF);
694 
695 	return 0;
696 }
697 
698 static int mv_xor_v2_resume(struct platform_device *dev)
699 {
700 	struct mv_xor_v2_device *xor_dev = platform_get_drvdata(dev);
701 
702 	mv_xor_v2_set_desc_size(xor_dev);
703 	mv_xor_v2_enable_imsg_thrd(xor_dev);
704 	mv_xor_v2_descq_init(xor_dev);
705 
706 	return 0;
707 }
708 
709 static int mv_xor_v2_probe(struct platform_device *pdev)
710 {
711 	struct mv_xor_v2_device *xor_dev;
712 	struct resource *res;
713 	int i, ret = 0;
714 	struct dma_device *dma_dev;
715 	struct mv_xor_v2_sw_desc *sw_desc;
716 	struct msi_desc *msi_desc;
717 
718 	BUILD_BUG_ON(sizeof(struct mv_xor_v2_descriptor) !=
719 		     MV_XOR_V2_EXT_DESC_SIZE);
720 
721 	xor_dev = devm_kzalloc(&pdev->dev, sizeof(*xor_dev), GFP_KERNEL);
722 	if (!xor_dev)
723 		return -ENOMEM;
724 
725 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
726 	xor_dev->dma_base = devm_ioremap_resource(&pdev->dev, res);
727 	if (IS_ERR(xor_dev->dma_base))
728 		return PTR_ERR(xor_dev->dma_base);
729 
730 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
731 	xor_dev->glob_base = devm_ioremap_resource(&pdev->dev, res);
732 	if (IS_ERR(xor_dev->glob_base))
733 		return PTR_ERR(xor_dev->glob_base);
734 
735 	platform_set_drvdata(pdev, xor_dev);
736 
737 	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40));
738 	if (ret)
739 		return ret;
740 
741 	xor_dev->reg_clk = devm_clk_get(&pdev->dev, "reg");
742 	if (PTR_ERR(xor_dev->reg_clk) != -ENOENT) {
743 		if (!IS_ERR(xor_dev->reg_clk)) {
744 			ret = clk_prepare_enable(xor_dev->reg_clk);
745 			if (ret)
746 				return ret;
747 		} else {
748 			return PTR_ERR(xor_dev->reg_clk);
749 		}
750 	}
751 
752 	xor_dev->clk = devm_clk_get(&pdev->dev, NULL);
753 	if (PTR_ERR(xor_dev->clk) == -EPROBE_DEFER) {
754 		ret = EPROBE_DEFER;
755 		goto disable_reg_clk;
756 	}
757 	if (!IS_ERR(xor_dev->clk)) {
758 		ret = clk_prepare_enable(xor_dev->clk);
759 		if (ret)
760 			goto disable_reg_clk;
761 	}
762 
763 	ret = platform_msi_domain_alloc_irqs(&pdev->dev, 1,
764 					     mv_xor_v2_set_msi_msg);
765 	if (ret)
766 		goto disable_clk;
767 
768 	msi_desc = first_msi_entry(&pdev->dev);
769 	if (!msi_desc)
770 		goto free_msi_irqs;
771 	xor_dev->msi_desc = msi_desc;
772 
773 	ret = devm_request_irq(&pdev->dev, msi_desc->irq,
774 			       mv_xor_v2_interrupt_handler, 0,
775 			       dev_name(&pdev->dev), xor_dev);
776 	if (ret)
777 		goto free_msi_irqs;
778 
779 	tasklet_init(&xor_dev->irq_tasklet, mv_xor_v2_tasklet,
780 		     (unsigned long) xor_dev);
781 
782 	xor_dev->desc_size = mv_xor_v2_set_desc_size(xor_dev);
783 
784 	dma_cookie_init(&xor_dev->dmachan);
785 
786 	/*
787 	 * allocate coherent memory for hardware descriptors
788 	 * note: writecombine gives slightly better performance, but
789 	 * requires that we explicitly flush the writes
790 	 */
791 	xor_dev->hw_desq_virt =
792 		dma_alloc_coherent(&pdev->dev,
793 				   xor_dev->desc_size * MV_XOR_V2_DESC_NUM,
794 				   &xor_dev->hw_desq, GFP_KERNEL);
795 	if (!xor_dev->hw_desq_virt) {
796 		ret = -ENOMEM;
797 		goto free_msi_irqs;
798 	}
799 
800 	/* alloc memory for the SW descriptors */
801 	xor_dev->sw_desq = devm_kcalloc(&pdev->dev,
802 					MV_XOR_V2_DESC_NUM, sizeof(*sw_desc),
803 					GFP_KERNEL);
804 	if (!xor_dev->sw_desq) {
805 		ret = -ENOMEM;
806 		goto free_hw_desq;
807 	}
808 
809 	spin_lock_init(&xor_dev->lock);
810 
811 	/* init the free SW descriptors list */
812 	INIT_LIST_HEAD(&xor_dev->free_sw_desc);
813 
814 	/* add all SW descriptors to the free list */
815 	for (i = 0; i < MV_XOR_V2_DESC_NUM; i++) {
816 		struct mv_xor_v2_sw_desc *sw_desc =
817 			xor_dev->sw_desq + i;
818 		sw_desc->idx = i;
819 		dma_async_tx_descriptor_init(&sw_desc->async_tx,
820 					     &xor_dev->dmachan);
821 		sw_desc->async_tx.tx_submit = mv_xor_v2_tx_submit;
822 		async_tx_ack(&sw_desc->async_tx);
823 
824 		list_add(&sw_desc->free_list,
825 			 &xor_dev->free_sw_desc);
826 	}
827 
828 	dma_dev = &xor_dev->dmadev;
829 
830 	/* set DMA capabilities */
831 	dma_cap_zero(dma_dev->cap_mask);
832 	dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
833 	dma_cap_set(DMA_XOR, dma_dev->cap_mask);
834 	dma_cap_set(DMA_INTERRUPT, dma_dev->cap_mask);
835 
836 	/* init dma link list */
837 	INIT_LIST_HEAD(&dma_dev->channels);
838 
839 	/* set base routines */
840 	dma_dev->device_tx_status = dma_cookie_status;
841 	dma_dev->device_issue_pending = mv_xor_v2_issue_pending;
842 	dma_dev->dev = &pdev->dev;
843 
844 	dma_dev->device_prep_dma_memcpy = mv_xor_v2_prep_dma_memcpy;
845 	dma_dev->device_prep_dma_interrupt = mv_xor_v2_prep_dma_interrupt;
846 	dma_dev->max_xor = 8;
847 	dma_dev->device_prep_dma_xor = mv_xor_v2_prep_dma_xor;
848 
849 	xor_dev->dmachan.device = dma_dev;
850 
851 	list_add_tail(&xor_dev->dmachan.device_node,
852 		      &dma_dev->channels);
853 
854 	mv_xor_v2_enable_imsg_thrd(xor_dev);
855 
856 	mv_xor_v2_descq_init(xor_dev);
857 
858 	ret = dma_async_device_register(dma_dev);
859 	if (ret)
860 		goto free_hw_desq;
861 
862 	dev_notice(&pdev->dev, "Marvell Version 2 XOR driver\n");
863 
864 	return 0;
865 
866 free_hw_desq:
867 	dma_free_coherent(&pdev->dev,
868 			  xor_dev->desc_size * MV_XOR_V2_DESC_NUM,
869 			  xor_dev->hw_desq_virt, xor_dev->hw_desq);
870 free_msi_irqs:
871 	platform_msi_domain_free_irqs(&pdev->dev);
872 disable_clk:
873 	clk_disable_unprepare(xor_dev->clk);
874 disable_reg_clk:
875 	clk_disable_unprepare(xor_dev->reg_clk);
876 	return ret;
877 }
878 
879 static int mv_xor_v2_remove(struct platform_device *pdev)
880 {
881 	struct mv_xor_v2_device *xor_dev = platform_get_drvdata(pdev);
882 
883 	dma_async_device_unregister(&xor_dev->dmadev);
884 
885 	dma_free_coherent(&pdev->dev,
886 			  xor_dev->desc_size * MV_XOR_V2_DESC_NUM,
887 			  xor_dev->hw_desq_virt, xor_dev->hw_desq);
888 
889 	devm_free_irq(&pdev->dev, xor_dev->msi_desc->irq, xor_dev);
890 
891 	platform_msi_domain_free_irqs(&pdev->dev);
892 
893 	tasklet_kill(&xor_dev->irq_tasklet);
894 
895 	clk_disable_unprepare(xor_dev->clk);
896 
897 	return 0;
898 }
899 
900 #ifdef CONFIG_OF
901 static const struct of_device_id mv_xor_v2_dt_ids[] = {
902 	{ .compatible = "marvell,xor-v2", },
903 	{},
904 };
905 MODULE_DEVICE_TABLE(of, mv_xor_v2_dt_ids);
906 #endif
907 
908 static struct platform_driver mv_xor_v2_driver = {
909 	.probe		= mv_xor_v2_probe,
910 	.suspend	= mv_xor_v2_suspend,
911 	.resume		= mv_xor_v2_resume,
912 	.remove		= mv_xor_v2_remove,
913 	.driver		= {
914 		.name	= "mv_xor_v2",
915 		.of_match_table = of_match_ptr(mv_xor_v2_dt_ids),
916 	},
917 };
918 
919 module_platform_driver(mv_xor_v2_driver);
920 
921 MODULE_DESCRIPTION("DMA engine driver for Marvell's Version 2 of XOR engine");
922 MODULE_LICENSE("GPL");
923