xref: /linux/drivers/dma/mv_xor_v2.c (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
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_THRD_SHIFT			0x0
37 #define   MV_XOR_V2_DMA_IMSG_TIMER_EN			BIT(18)
38 #define MV_XOR_V2_DMA_DESQ_AWATTR_OFF			0x01C
39   /* Same flags as MV_XOR_V2_DMA_DESQ_ARATTR_OFF */
40 #define MV_XOR_V2_DMA_DESQ_ALLOC_OFF			0x04C
41 #define   MV_XOR_V2_DMA_DESQ_ALLOC_WRPTR_MASK		0xFFFF
42 #define   MV_XOR_V2_DMA_DESQ_ALLOC_WRPTR_SHIFT		16
43 #define MV_XOR_V2_DMA_IMSG_BALR_OFF			0x050
44 #define MV_XOR_V2_DMA_IMSG_BAHR_OFF			0x054
45 #define MV_XOR_V2_DMA_DESQ_CTRL_OFF			0x100
46 #define	  MV_XOR_V2_DMA_DESQ_CTRL_32B			1
47 #define   MV_XOR_V2_DMA_DESQ_CTRL_128B			7
48 #define MV_XOR_V2_DMA_DESQ_STOP_OFF			0x800
49 #define MV_XOR_V2_DMA_DESQ_DEALLOC_OFF			0x804
50 #define MV_XOR_V2_DMA_DESQ_ADD_OFF			0x808
51 #define MV_XOR_V2_DMA_IMSG_TMOT				0x810
52 #define   MV_XOR_V2_DMA_IMSG_TIMER_THRD_MASK		0x1FFF
53 #define   MV_XOR_V2_DMA_IMSG_TIMER_THRD_SHIFT		0
54 
55 /* XOR Global registers */
56 #define MV_XOR_V2_GLOB_BW_CTRL				0x4
57 #define   MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_RD_SHIFT	0
58 #define   MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_RD_VAL	64
59 #define   MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_WR_SHIFT	8
60 #define   MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_WR_VAL	8
61 #define   MV_XOR_V2_GLOB_BW_CTRL_RD_BURST_LEN_SHIFT	12
62 #define   MV_XOR_V2_GLOB_BW_CTRL_RD_BURST_LEN_VAL	4
63 #define   MV_XOR_V2_GLOB_BW_CTRL_WR_BURST_LEN_SHIFT	16
64 #define	  MV_XOR_V2_GLOB_BW_CTRL_WR_BURST_LEN_VAL	4
65 #define MV_XOR_V2_GLOB_PAUSE				0x014
66 #define   MV_XOR_V2_GLOB_PAUSE_AXI_TIME_DIS_VAL		0x8
67 #define MV_XOR_V2_GLOB_SYS_INT_CAUSE			0x200
68 #define MV_XOR_V2_GLOB_SYS_INT_MASK			0x204
69 #define MV_XOR_V2_GLOB_MEM_INT_CAUSE			0x220
70 #define MV_XOR_V2_GLOB_MEM_INT_MASK			0x224
71 
72 #define MV_XOR_V2_MIN_DESC_SIZE				32
73 #define MV_XOR_V2_EXT_DESC_SIZE				128
74 
75 #define MV_XOR_V2_DESC_RESERVED_SIZE			12
76 #define MV_XOR_V2_DESC_BUFF_D_ADDR_SIZE			12
77 
78 #define MV_XOR_V2_CMD_LINE_NUM_MAX_D_BUF		8
79 
80 /*
81  * Descriptors queue size. With 32 bytes descriptors, up to 2^14
82  * descriptors are allowed, with 128 bytes descriptors, up to 2^12
83  * descriptors are allowed. This driver uses 128 bytes descriptors,
84  * but experimentation has shown that a set of 1024 descriptors is
85  * sufficient to reach a good level of performance.
86  */
87 #define MV_XOR_V2_DESC_NUM				1024
88 
89 /*
90  * Threshold values for descriptors and timeout, determined by
91  * experimentation as giving a good level of performance.
92  */
93 #define MV_XOR_V2_DONE_IMSG_THRD  0x14
94 #define MV_XOR_V2_TIMER_THRD      0xB0
95 
96 /**
97  * struct mv_xor_v2_descriptor - DMA HW descriptor
98  * @desc_id: used by S/W and is not affected by H/W.
99  * @flags: error and status flags
100  * @crc32_result: CRC32 calculation result
101  * @desc_ctrl: operation mode and control flags
102  * @buff_size: amount of bytes to be processed
103  * @fill_pattern_src_addr: Fill-Pattern or Source-Address and
104  * AW-Attributes
105  * @data_buff_addr: Source (and might be RAID6 destination)
106  * addresses of data buffers in RAID5 and RAID6
107  * @reserved: reserved
108  */
109 struct mv_xor_v2_descriptor {
110 	u16 desc_id;
111 	u16 flags;
112 	u32 crc32_result;
113 	u32 desc_ctrl;
114 
115 	/* Definitions for desc_ctrl */
116 #define DESC_NUM_ACTIVE_D_BUF_SHIFT	22
117 #define DESC_OP_MODE_SHIFT		28
118 #define DESC_OP_MODE_NOP		0	/* Idle operation */
119 #define DESC_OP_MODE_MEMCPY		1	/* Pure-DMA operation */
120 #define DESC_OP_MODE_MEMSET		2	/* Mem-Fill operation */
121 #define DESC_OP_MODE_MEMINIT		3	/* Mem-Init operation */
122 #define DESC_OP_MODE_MEM_COMPARE	4	/* Mem-Compare operation */
123 #define DESC_OP_MODE_CRC32		5	/* CRC32 calculation */
124 #define DESC_OP_MODE_XOR		6	/* RAID5 (XOR) operation */
125 #define DESC_OP_MODE_RAID6		7	/* RAID6 P&Q-generation */
126 #define DESC_OP_MODE_RAID6_REC		8	/* RAID6 Recovery */
127 #define DESC_Q_BUFFER_ENABLE		BIT(16)
128 #define DESC_P_BUFFER_ENABLE		BIT(17)
129 #define DESC_IOD			BIT(27)
130 
131 	u32 buff_size;
132 	u32 fill_pattern_src_addr[4];
133 	u32 data_buff_addr[MV_XOR_V2_DESC_BUFF_D_ADDR_SIZE];
134 	u32 reserved[MV_XOR_V2_DESC_RESERVED_SIZE];
135 };
136 
137 /**
138  * struct mv_xor_v2_device - implements a xor device
139  * @lock: lock for the engine
140  * @dma_base: memory mapped DMA register base
141  * @glob_base: memory mapped global register base
142  * @irq_tasklet:
143  * @free_sw_desc: linked list of free SW descriptors
144  * @dmadev: dma device
145  * @dmachan: dma channel
146  * @hw_desq: HW descriptors queue
147  * @hw_desq_virt: virtual address of DESCQ
148  * @sw_desq: SW descriptors queue
149  * @desc_size: HW descriptor size
150  * @npendings: number of pending descriptors (for which tx_submit has
151  * been called, but not yet issue_pending)
152  */
153 struct mv_xor_v2_device {
154 	spinlock_t lock;
155 	void __iomem *dma_base;
156 	void __iomem *glob_base;
157 	struct clk *clk;
158 	struct clk *reg_clk;
159 	struct tasklet_struct irq_tasklet;
160 	struct list_head free_sw_desc;
161 	struct dma_device dmadev;
162 	struct dma_chan	dmachan;
163 	dma_addr_t hw_desq;
164 	struct mv_xor_v2_descriptor *hw_desq_virt;
165 	struct mv_xor_v2_sw_desc *sw_desq;
166 	int desc_size;
167 	unsigned int npendings;
168 	unsigned int hw_queue_idx;
169 	struct msi_desc *msi_desc;
170 };
171 
172 /**
173  * struct mv_xor_v2_sw_desc - implements a xor SW descriptor
174  * @idx: descriptor index
175  * @async_tx: support for the async_tx api
176  * @hw_desc: assosiated HW descriptor
177  * @free_list: node of the free SW descriprots list
178 */
179 struct mv_xor_v2_sw_desc {
180 	int idx;
181 	struct dma_async_tx_descriptor async_tx;
182 	struct mv_xor_v2_descriptor hw_desc;
183 	struct list_head free_list;
184 };
185 
186 /*
187  * Fill the data buffers to a HW descriptor
188  */
189 static void mv_xor_v2_set_data_buffers(struct mv_xor_v2_device *xor_dev,
190 					struct mv_xor_v2_descriptor *desc,
191 					dma_addr_t src, int index)
192 {
193 	int arr_index = ((index >> 1) * 3);
194 
195 	/*
196 	 * Fill the buffer's addresses to the descriptor.
197 	 *
198 	 * The format of the buffers address for 2 sequential buffers
199 	 * X and X + 1:
200 	 *
201 	 *  First word:  Buffer-DX-Address-Low[31:0]
202 	 *  Second word: Buffer-DX+1-Address-Low[31:0]
203 	 *  Third word:  DX+1-Buffer-Address-High[47:32] [31:16]
204 	 *		 DX-Buffer-Address-High[47:32] [15:0]
205 	 */
206 	if ((index & 0x1) == 0) {
207 		desc->data_buff_addr[arr_index] = lower_32_bits(src);
208 
209 		desc->data_buff_addr[arr_index + 2] &= ~0xFFFF;
210 		desc->data_buff_addr[arr_index + 2] |=
211 			upper_32_bits(src) & 0xFFFF;
212 	} else {
213 		desc->data_buff_addr[arr_index + 1] =
214 			lower_32_bits(src);
215 
216 		desc->data_buff_addr[arr_index + 2] &= ~0xFFFF0000;
217 		desc->data_buff_addr[arr_index + 2] |=
218 			(upper_32_bits(src) & 0xFFFF) << 16;
219 	}
220 }
221 
222 /*
223  * notify the engine of new descriptors, and update the available index.
224  */
225 static void mv_xor_v2_add_desc_to_desq(struct mv_xor_v2_device *xor_dev,
226 				       int num_of_desc)
227 {
228 	/* write the number of new descriptors in the DESQ. */
229 	writel(num_of_desc, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_ADD_OFF);
230 }
231 
232 /*
233  * free HW descriptors
234  */
235 static void mv_xor_v2_free_desc_from_desq(struct mv_xor_v2_device *xor_dev,
236 					  int num_of_desc)
237 {
238 	/* write the number of new descriptors in the DESQ. */
239 	writel(num_of_desc, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_DEALLOC_OFF);
240 }
241 
242 /*
243  * Set descriptor size
244  * Return the HW descriptor size in bytes
245  */
246 static int mv_xor_v2_set_desc_size(struct mv_xor_v2_device *xor_dev)
247 {
248 	writel(MV_XOR_V2_DMA_DESQ_CTRL_128B,
249 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_CTRL_OFF);
250 
251 	return MV_XOR_V2_EXT_DESC_SIZE;
252 }
253 
254 /*
255  * Set the IMSG threshold
256  */
257 static inline
258 void mv_xor_v2_enable_imsg_thrd(struct mv_xor_v2_device *xor_dev)
259 {
260 	u32 reg;
261 
262 	/* Configure threshold of number of descriptors, and enable timer */
263 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
264 	reg &= (~MV_XOR_V2_DMA_IMSG_THRD_MASK << MV_XOR_V2_DMA_IMSG_THRD_SHIFT);
265 	reg |= (MV_XOR_V2_DONE_IMSG_THRD << MV_XOR_V2_DMA_IMSG_THRD_SHIFT);
266 	reg |= MV_XOR_V2_DMA_IMSG_TIMER_EN;
267 	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
268 
269 	/* Configure Timer Threshold */
270 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_TMOT);
271 	reg &= (~MV_XOR_V2_DMA_IMSG_TIMER_THRD_MASK <<
272 		MV_XOR_V2_DMA_IMSG_TIMER_THRD_SHIFT);
273 	reg |= (MV_XOR_V2_TIMER_THRD << MV_XOR_V2_DMA_IMSG_TIMER_THRD_SHIFT);
274 	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_TMOT);
275 }
276 
277 static irqreturn_t mv_xor_v2_interrupt_handler(int irq, void *data)
278 {
279 	struct mv_xor_v2_device *xor_dev = data;
280 	unsigned int ndescs;
281 	u32 reg;
282 
283 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_DONE_OFF);
284 
285 	ndescs = ((reg >> MV_XOR_V2_DMA_DESQ_DONE_PENDING_SHIFT) &
286 		  MV_XOR_V2_DMA_DESQ_DONE_PENDING_MASK);
287 
288 	/* No descriptors to process */
289 	if (!ndescs)
290 		return IRQ_NONE;
291 
292 	/* schedule a tasklet to handle descriptors callbacks */
293 	tasklet_schedule(&xor_dev->irq_tasklet);
294 
295 	return IRQ_HANDLED;
296 }
297 
298 /*
299  * submit a descriptor to the DMA engine
300  */
301 static dma_cookie_t
302 mv_xor_v2_tx_submit(struct dma_async_tx_descriptor *tx)
303 {
304 	void *dest_hw_desc;
305 	dma_cookie_t cookie;
306 	struct mv_xor_v2_sw_desc *sw_desc =
307 		container_of(tx, struct mv_xor_v2_sw_desc, async_tx);
308 	struct mv_xor_v2_device *xor_dev =
309 		container_of(tx->chan, struct mv_xor_v2_device, dmachan);
310 
311 	dev_dbg(xor_dev->dmadev.dev,
312 		"%s sw_desc %p: async_tx %p\n",
313 		__func__, sw_desc, &sw_desc->async_tx);
314 
315 	/* assign coookie */
316 	spin_lock_bh(&xor_dev->lock);
317 	cookie = dma_cookie_assign(tx);
318 
319 	/* copy the HW descriptor from the SW descriptor to the DESQ */
320 	dest_hw_desc = xor_dev->hw_desq_virt + xor_dev->hw_queue_idx;
321 
322 	memcpy(dest_hw_desc, &sw_desc->hw_desc, xor_dev->desc_size);
323 
324 	xor_dev->npendings++;
325 	xor_dev->hw_queue_idx++;
326 	if (xor_dev->hw_queue_idx >= MV_XOR_V2_DESC_NUM)
327 		xor_dev->hw_queue_idx = 0;
328 
329 	spin_unlock_bh(&xor_dev->lock);
330 
331 	return cookie;
332 }
333 
334 /*
335  * Prepare a SW descriptor
336  */
337 static struct mv_xor_v2_sw_desc	*
338 mv_xor_v2_prep_sw_desc(struct mv_xor_v2_device *xor_dev)
339 {
340 	struct mv_xor_v2_sw_desc *sw_desc;
341 	bool found = false;
342 
343 	/* Lock the channel */
344 	spin_lock_bh(&xor_dev->lock);
345 
346 	if (list_empty(&xor_dev->free_sw_desc)) {
347 		spin_unlock_bh(&xor_dev->lock);
348 		/* schedule tasklet to free some descriptors */
349 		tasklet_schedule(&xor_dev->irq_tasklet);
350 		return NULL;
351 	}
352 
353 	list_for_each_entry(sw_desc, &xor_dev->free_sw_desc, free_list) {
354 		if (async_tx_test_ack(&sw_desc->async_tx)) {
355 			found = true;
356 			break;
357 		}
358 	}
359 
360 	if (!found) {
361 		spin_unlock_bh(&xor_dev->lock);
362 		return NULL;
363 	}
364 
365 	list_del(&sw_desc->free_list);
366 
367 	/* Release the channel */
368 	spin_unlock_bh(&xor_dev->lock);
369 
370 	return sw_desc;
371 }
372 
373 /*
374  * Prepare a HW descriptor for a memcpy operation
375  */
376 static struct dma_async_tx_descriptor *
377 mv_xor_v2_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest,
378 			  dma_addr_t src, size_t len, unsigned long flags)
379 {
380 	struct mv_xor_v2_sw_desc *sw_desc;
381 	struct mv_xor_v2_descriptor *hw_descriptor;
382 	struct mv_xor_v2_device	*xor_dev;
383 
384 	xor_dev = container_of(chan, struct mv_xor_v2_device, dmachan);
385 
386 	dev_dbg(xor_dev->dmadev.dev,
387 		"%s len: %zu src %pad dest %pad flags: %ld\n",
388 		__func__, len, &src, &dest, flags);
389 
390 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
391 	if (!sw_desc)
392 		return NULL;
393 
394 	sw_desc->async_tx.flags = flags;
395 
396 	/* set the HW descriptor */
397 	hw_descriptor = &sw_desc->hw_desc;
398 
399 	/* save the SW descriptor ID to restore when operation is done */
400 	hw_descriptor->desc_id = sw_desc->idx;
401 
402 	/* Set the MEMCPY control word */
403 	hw_descriptor->desc_ctrl =
404 		DESC_OP_MODE_MEMCPY << DESC_OP_MODE_SHIFT;
405 
406 	if (flags & DMA_PREP_INTERRUPT)
407 		hw_descriptor->desc_ctrl |= DESC_IOD;
408 
409 	/* Set source address */
410 	hw_descriptor->fill_pattern_src_addr[0] = lower_32_bits(src);
411 	hw_descriptor->fill_pattern_src_addr[1] =
412 		upper_32_bits(src) & 0xFFFF;
413 
414 	/* Set Destination address */
415 	hw_descriptor->fill_pattern_src_addr[2] = lower_32_bits(dest);
416 	hw_descriptor->fill_pattern_src_addr[3] =
417 		upper_32_bits(dest) & 0xFFFF;
418 
419 	/* Set buffers size */
420 	hw_descriptor->buff_size = len;
421 
422 	/* return the async tx descriptor */
423 	return &sw_desc->async_tx;
424 }
425 
426 /*
427  * Prepare a HW descriptor for a XOR operation
428  */
429 static struct dma_async_tx_descriptor *
430 mv_xor_v2_prep_dma_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
431 		       unsigned int src_cnt, size_t len, unsigned long flags)
432 {
433 	struct mv_xor_v2_sw_desc *sw_desc;
434 	struct mv_xor_v2_descriptor *hw_descriptor;
435 	struct mv_xor_v2_device	*xor_dev =
436 		container_of(chan, struct mv_xor_v2_device, dmachan);
437 	int i;
438 
439 	if (src_cnt > MV_XOR_V2_CMD_LINE_NUM_MAX_D_BUF || src_cnt < 1)
440 		return NULL;
441 
442 	dev_dbg(xor_dev->dmadev.dev,
443 		"%s src_cnt: %d len: %zu dest %pad flags: %ld\n",
444 		__func__, src_cnt, len, &dest, flags);
445 
446 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
447 	if (!sw_desc)
448 		return NULL;
449 
450 	sw_desc->async_tx.flags = flags;
451 
452 	/* set the HW descriptor */
453 	hw_descriptor = &sw_desc->hw_desc;
454 
455 	/* save the SW descriptor ID to restore when operation is done */
456 	hw_descriptor->desc_id = sw_desc->idx;
457 
458 	/* Set the XOR control word */
459 	hw_descriptor->desc_ctrl =
460 		DESC_OP_MODE_XOR << DESC_OP_MODE_SHIFT;
461 	hw_descriptor->desc_ctrl |= DESC_P_BUFFER_ENABLE;
462 
463 	if (flags & DMA_PREP_INTERRUPT)
464 		hw_descriptor->desc_ctrl |= DESC_IOD;
465 
466 	/* Set the data buffers */
467 	for (i = 0; i < src_cnt; i++)
468 		mv_xor_v2_set_data_buffers(xor_dev, hw_descriptor, src[i], i);
469 
470 	hw_descriptor->desc_ctrl |=
471 		src_cnt << DESC_NUM_ACTIVE_D_BUF_SHIFT;
472 
473 	/* Set Destination address */
474 	hw_descriptor->fill_pattern_src_addr[2] = lower_32_bits(dest);
475 	hw_descriptor->fill_pattern_src_addr[3] =
476 		upper_32_bits(dest) & 0xFFFF;
477 
478 	/* Set buffers size */
479 	hw_descriptor->buff_size = len;
480 
481 	/* return the async tx descriptor */
482 	return &sw_desc->async_tx;
483 }
484 
485 /*
486  * Prepare a HW descriptor for interrupt operation.
487  */
488 static struct dma_async_tx_descriptor *
489 mv_xor_v2_prep_dma_interrupt(struct dma_chan *chan, unsigned long flags)
490 {
491 	struct mv_xor_v2_sw_desc *sw_desc;
492 	struct mv_xor_v2_descriptor *hw_descriptor;
493 	struct mv_xor_v2_device	*xor_dev =
494 		container_of(chan, struct mv_xor_v2_device, dmachan);
495 
496 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
497 	if (!sw_desc)
498 		return NULL;
499 
500 	/* set the HW descriptor */
501 	hw_descriptor = &sw_desc->hw_desc;
502 
503 	/* save the SW descriptor ID to restore when operation is done */
504 	hw_descriptor->desc_id = sw_desc->idx;
505 
506 	/* Set the INTERRUPT control word */
507 	hw_descriptor->desc_ctrl =
508 		DESC_OP_MODE_NOP << DESC_OP_MODE_SHIFT;
509 	hw_descriptor->desc_ctrl |= DESC_IOD;
510 
511 	/* return the async tx descriptor */
512 	return &sw_desc->async_tx;
513 }
514 
515 /*
516  * push pending transactions to hardware
517  */
518 static void mv_xor_v2_issue_pending(struct dma_chan *chan)
519 {
520 	struct mv_xor_v2_device *xor_dev =
521 		container_of(chan, struct mv_xor_v2_device, dmachan);
522 
523 	spin_lock_bh(&xor_dev->lock);
524 
525 	/*
526 	 * update the engine with the number of descriptors to
527 	 * process
528 	 */
529 	mv_xor_v2_add_desc_to_desq(xor_dev, xor_dev->npendings);
530 	xor_dev->npendings = 0;
531 
532 	spin_unlock_bh(&xor_dev->lock);
533 }
534 
535 static inline
536 int mv_xor_v2_get_pending_params(struct mv_xor_v2_device *xor_dev,
537 				 int *pending_ptr)
538 {
539 	u32 reg;
540 
541 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_DONE_OFF);
542 
543 	/* get the next pending descriptor index */
544 	*pending_ptr = ((reg >> MV_XOR_V2_DMA_DESQ_DONE_READ_PTR_SHIFT) &
545 			MV_XOR_V2_DMA_DESQ_DONE_READ_PTR_MASK);
546 
547 	/* get the number of descriptors pending handle */
548 	return ((reg >> MV_XOR_V2_DMA_DESQ_DONE_PENDING_SHIFT) &
549 		MV_XOR_V2_DMA_DESQ_DONE_PENDING_MASK);
550 }
551 
552 /*
553  * handle the descriptors after HW process
554  */
555 static void mv_xor_v2_tasklet(unsigned long data)
556 {
557 	struct mv_xor_v2_device *xor_dev = (struct mv_xor_v2_device *) data;
558 	int pending_ptr, num_of_pending, i;
559 	struct mv_xor_v2_sw_desc *next_pending_sw_desc = NULL;
560 
561 	dev_dbg(xor_dev->dmadev.dev, "%s %d\n", __func__, __LINE__);
562 
563 	/* get the pending descriptors parameters */
564 	num_of_pending = mv_xor_v2_get_pending_params(xor_dev, &pending_ptr);
565 
566 	/* loop over free descriptors */
567 	for (i = 0; i < num_of_pending; i++) {
568 		struct mv_xor_v2_descriptor *next_pending_hw_desc =
569 			xor_dev->hw_desq_virt + pending_ptr;
570 
571 		/* get the SW descriptor related to the HW descriptor */
572 		next_pending_sw_desc =
573 			&xor_dev->sw_desq[next_pending_hw_desc->desc_id];
574 
575 		/* call the callback */
576 		if (next_pending_sw_desc->async_tx.cookie > 0) {
577 			/*
578 			 * update the channel's completed cookie - no
579 			 * lock is required the IMSG threshold provide
580 			 * the locking
581 			 */
582 			dma_cookie_complete(&next_pending_sw_desc->async_tx);
583 
584 			dma_descriptor_unmap(&next_pending_sw_desc->async_tx);
585 			dmaengine_desc_get_callback_invoke(
586 					&next_pending_sw_desc->async_tx, NULL);
587 		}
588 
589 		dma_run_dependencies(&next_pending_sw_desc->async_tx);
590 
591 		/* Lock the channel */
592 		spin_lock_bh(&xor_dev->lock);
593 
594 		/* add the SW descriptor to the free descriptors list */
595 		list_add(&next_pending_sw_desc->free_list,
596 			 &xor_dev->free_sw_desc);
597 
598 		/* Release the channel */
599 		spin_unlock_bh(&xor_dev->lock);
600 
601 		/* increment the next descriptor */
602 		pending_ptr++;
603 		if (pending_ptr >= MV_XOR_V2_DESC_NUM)
604 			pending_ptr = 0;
605 	}
606 
607 	if (num_of_pending != 0) {
608 		/* free the descriptores */
609 		mv_xor_v2_free_desc_from_desq(xor_dev, num_of_pending);
610 	}
611 }
612 
613 /*
614  *	Set DMA Interrupt-message (IMSG) parameters
615  */
616 static void mv_xor_v2_set_msi_msg(struct msi_desc *desc, struct msi_msg *msg)
617 {
618 	struct mv_xor_v2_device *xor_dev = dev_get_drvdata(desc->dev);
619 
620 	writel(msg->address_lo,
621 	       xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_BALR_OFF);
622 	writel(msg->address_hi & 0xFFFF,
623 	       xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_BAHR_OFF);
624 	writel(msg->data,
625 	       xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_CDAT_OFF);
626 }
627 
628 static int mv_xor_v2_descq_init(struct mv_xor_v2_device *xor_dev)
629 {
630 	u32 reg;
631 
632 	/* write the DESQ size to the DMA engine */
633 	writel(MV_XOR_V2_DESC_NUM,
634 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_SIZE_OFF);
635 
636 	/* write the DESQ address to the DMA enngine*/
637 	writel(lower_32_bits(xor_dev->hw_desq),
638 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_BALR_OFF);
639 	writel(upper_32_bits(xor_dev->hw_desq),
640 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_BAHR_OFF);
641 
642 	/*
643 	 * This is a temporary solution, until we activate the
644 	 * SMMU. Set the attributes for reading & writing data buffers
645 	 * & descriptors to:
646 	 *
647 	 *  - OuterShareable - Snoops will be performed on CPU caches
648 	 *  - Enable cacheable - Bufferable, Modifiable, Other Allocate
649 	 *    and Allocate
650 	 */
651 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_ARATTR_OFF);
652 	reg &= ~MV_XOR_V2_DMA_DESQ_ATTR_CACHE_MASK;
653 	reg |= MV_XOR_V2_DMA_DESQ_ATTR_OUTER_SHAREABLE |
654 		MV_XOR_V2_DMA_DESQ_ATTR_CACHEABLE;
655 	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_ARATTR_OFF);
656 
657 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_AWATTR_OFF);
658 	reg &= ~MV_XOR_V2_DMA_DESQ_ATTR_CACHE_MASK;
659 	reg |= MV_XOR_V2_DMA_DESQ_ATTR_OUTER_SHAREABLE |
660 		MV_XOR_V2_DMA_DESQ_ATTR_CACHEABLE;
661 	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_AWATTR_OFF);
662 
663 	/* BW CTRL - set values to optimize the XOR performance:
664 	 *
665 	 *  - Set WrBurstLen & RdBurstLen - the unit will issue
666 	 *    maximum of 256B write/read transactions.
667 	 * -  Limit the number of outstanding write & read data
668 	 *    (OBB/IBB) requests to the maximal value.
669 	*/
670 	reg = ((MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_RD_VAL <<
671 		MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_RD_SHIFT) |
672 	       (MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_WR_VAL  <<
673 		MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_WR_SHIFT) |
674 	       (MV_XOR_V2_GLOB_BW_CTRL_RD_BURST_LEN_VAL <<
675 		MV_XOR_V2_GLOB_BW_CTRL_RD_BURST_LEN_SHIFT) |
676 	       (MV_XOR_V2_GLOB_BW_CTRL_WR_BURST_LEN_VAL <<
677 		MV_XOR_V2_GLOB_BW_CTRL_WR_BURST_LEN_SHIFT));
678 	writel(reg, xor_dev->glob_base + MV_XOR_V2_GLOB_BW_CTRL);
679 
680 	/* Disable the AXI timer feature */
681 	reg = readl(xor_dev->glob_base + MV_XOR_V2_GLOB_PAUSE);
682 	reg |= MV_XOR_V2_GLOB_PAUSE_AXI_TIME_DIS_VAL;
683 	writel(reg, xor_dev->glob_base + MV_XOR_V2_GLOB_PAUSE);
684 
685 	/* enable the DMA engine */
686 	writel(0, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_STOP_OFF);
687 
688 	return 0;
689 }
690 
691 static int mv_xor_v2_suspend(struct platform_device *dev, pm_message_t state)
692 {
693 	struct mv_xor_v2_device *xor_dev = platform_get_drvdata(dev);
694 
695 	/* Set this bit to disable to stop the XOR unit. */
696 	writel(0x1, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_STOP_OFF);
697 
698 	return 0;
699 }
700 
701 static int mv_xor_v2_resume(struct platform_device *dev)
702 {
703 	struct mv_xor_v2_device *xor_dev = platform_get_drvdata(dev);
704 
705 	mv_xor_v2_set_desc_size(xor_dev);
706 	mv_xor_v2_enable_imsg_thrd(xor_dev);
707 	mv_xor_v2_descq_init(xor_dev);
708 
709 	return 0;
710 }
711 
712 static int mv_xor_v2_probe(struct platform_device *pdev)
713 {
714 	struct mv_xor_v2_device *xor_dev;
715 	struct resource *res;
716 	int i, ret = 0;
717 	struct dma_device *dma_dev;
718 	struct mv_xor_v2_sw_desc *sw_desc;
719 	struct msi_desc *msi_desc;
720 
721 	BUILD_BUG_ON(sizeof(struct mv_xor_v2_descriptor) !=
722 		     MV_XOR_V2_EXT_DESC_SIZE);
723 
724 	xor_dev = devm_kzalloc(&pdev->dev, sizeof(*xor_dev), GFP_KERNEL);
725 	if (!xor_dev)
726 		return -ENOMEM;
727 
728 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
729 	xor_dev->dma_base = devm_ioremap_resource(&pdev->dev, res);
730 	if (IS_ERR(xor_dev->dma_base))
731 		return PTR_ERR(xor_dev->dma_base);
732 
733 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
734 	xor_dev->glob_base = devm_ioremap_resource(&pdev->dev, res);
735 	if (IS_ERR(xor_dev->glob_base))
736 		return PTR_ERR(xor_dev->glob_base);
737 
738 	platform_set_drvdata(pdev, xor_dev);
739 
740 	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40));
741 	if (ret)
742 		return ret;
743 
744 	xor_dev->reg_clk = devm_clk_get(&pdev->dev, "reg");
745 	if (PTR_ERR(xor_dev->reg_clk) != -ENOENT) {
746 		if (!IS_ERR(xor_dev->reg_clk)) {
747 			ret = clk_prepare_enable(xor_dev->reg_clk);
748 			if (ret)
749 				return ret;
750 		} else {
751 			return PTR_ERR(xor_dev->reg_clk);
752 		}
753 	}
754 
755 	xor_dev->clk = devm_clk_get(&pdev->dev, NULL);
756 	if (IS_ERR(xor_dev->clk) && PTR_ERR(xor_dev->clk) == -EPROBE_DEFER) {
757 		ret = EPROBE_DEFER;
758 		goto disable_reg_clk;
759 	}
760 	if (!IS_ERR(xor_dev->clk)) {
761 		ret = clk_prepare_enable(xor_dev->clk);
762 		if (ret)
763 			goto disable_reg_clk;
764 	}
765 
766 	ret = platform_msi_domain_alloc_irqs(&pdev->dev, 1,
767 					     mv_xor_v2_set_msi_msg);
768 	if (ret)
769 		goto disable_clk;
770 
771 	msi_desc = first_msi_entry(&pdev->dev);
772 	if (!msi_desc)
773 		goto free_msi_irqs;
774 	xor_dev->msi_desc = msi_desc;
775 
776 	ret = devm_request_irq(&pdev->dev, msi_desc->irq,
777 			       mv_xor_v2_interrupt_handler, 0,
778 			       dev_name(&pdev->dev), xor_dev);
779 	if (ret)
780 		goto free_msi_irqs;
781 
782 	tasklet_init(&xor_dev->irq_tasklet, mv_xor_v2_tasklet,
783 		     (unsigned long) xor_dev);
784 
785 	xor_dev->desc_size = mv_xor_v2_set_desc_size(xor_dev);
786 
787 	dma_cookie_init(&xor_dev->dmachan);
788 
789 	/*
790 	 * allocate coherent memory for hardware descriptors
791 	 * note: writecombine gives slightly better performance, but
792 	 * requires that we explicitly flush the writes
793 	 */
794 	xor_dev->hw_desq_virt =
795 		dma_alloc_coherent(&pdev->dev,
796 				   xor_dev->desc_size * MV_XOR_V2_DESC_NUM,
797 				   &xor_dev->hw_desq, GFP_KERNEL);
798 	if (!xor_dev->hw_desq_virt) {
799 		ret = -ENOMEM;
800 		goto free_msi_irqs;
801 	}
802 
803 	/* alloc memory for the SW descriptors */
804 	xor_dev->sw_desq = devm_kcalloc(&pdev->dev,
805 					MV_XOR_V2_DESC_NUM, sizeof(*sw_desc),
806 					GFP_KERNEL);
807 	if (!xor_dev->sw_desq) {
808 		ret = -ENOMEM;
809 		goto free_hw_desq;
810 	}
811 
812 	spin_lock_init(&xor_dev->lock);
813 
814 	/* init the free SW descriptors list */
815 	INIT_LIST_HEAD(&xor_dev->free_sw_desc);
816 
817 	/* add all SW descriptors to the free list */
818 	for (i = 0; i < MV_XOR_V2_DESC_NUM; i++) {
819 		struct mv_xor_v2_sw_desc *sw_desc =
820 			xor_dev->sw_desq + i;
821 		sw_desc->idx = i;
822 		dma_async_tx_descriptor_init(&sw_desc->async_tx,
823 					     &xor_dev->dmachan);
824 		sw_desc->async_tx.tx_submit = mv_xor_v2_tx_submit;
825 		async_tx_ack(&sw_desc->async_tx);
826 
827 		list_add(&sw_desc->free_list,
828 			 &xor_dev->free_sw_desc);
829 	}
830 
831 	dma_dev = &xor_dev->dmadev;
832 
833 	/* set DMA capabilities */
834 	dma_cap_zero(dma_dev->cap_mask);
835 	dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
836 	dma_cap_set(DMA_XOR, dma_dev->cap_mask);
837 	dma_cap_set(DMA_INTERRUPT, dma_dev->cap_mask);
838 
839 	/* init dma link list */
840 	INIT_LIST_HEAD(&dma_dev->channels);
841 
842 	/* set base routines */
843 	dma_dev->device_tx_status = dma_cookie_status;
844 	dma_dev->device_issue_pending = mv_xor_v2_issue_pending;
845 	dma_dev->dev = &pdev->dev;
846 
847 	dma_dev->device_prep_dma_memcpy = mv_xor_v2_prep_dma_memcpy;
848 	dma_dev->device_prep_dma_interrupt = mv_xor_v2_prep_dma_interrupt;
849 	dma_dev->max_xor = 8;
850 	dma_dev->device_prep_dma_xor = mv_xor_v2_prep_dma_xor;
851 
852 	xor_dev->dmachan.device = dma_dev;
853 
854 	list_add_tail(&xor_dev->dmachan.device_node,
855 		      &dma_dev->channels);
856 
857 	mv_xor_v2_enable_imsg_thrd(xor_dev);
858 
859 	mv_xor_v2_descq_init(xor_dev);
860 
861 	ret = dma_async_device_register(dma_dev);
862 	if (ret)
863 		goto free_hw_desq;
864 
865 	dev_notice(&pdev->dev, "Marvell Version 2 XOR driver\n");
866 
867 	return 0;
868 
869 free_hw_desq:
870 	dma_free_coherent(&pdev->dev,
871 			  xor_dev->desc_size * MV_XOR_V2_DESC_NUM,
872 			  xor_dev->hw_desq_virt, xor_dev->hw_desq);
873 free_msi_irqs:
874 	platform_msi_domain_free_irqs(&pdev->dev);
875 disable_clk:
876 	clk_disable_unprepare(xor_dev->clk);
877 disable_reg_clk:
878 	clk_disable_unprepare(xor_dev->reg_clk);
879 	return ret;
880 }
881 
882 static int mv_xor_v2_remove(struct platform_device *pdev)
883 {
884 	struct mv_xor_v2_device *xor_dev = platform_get_drvdata(pdev);
885 
886 	dma_async_device_unregister(&xor_dev->dmadev);
887 
888 	dma_free_coherent(&pdev->dev,
889 			  xor_dev->desc_size * MV_XOR_V2_DESC_NUM,
890 			  xor_dev->hw_desq_virt, xor_dev->hw_desq);
891 
892 	devm_free_irq(&pdev->dev, xor_dev->msi_desc->irq, xor_dev);
893 
894 	platform_msi_domain_free_irqs(&pdev->dev);
895 
896 	tasklet_kill(&xor_dev->irq_tasklet);
897 
898 	clk_disable_unprepare(xor_dev->clk);
899 
900 	return 0;
901 }
902 
903 #ifdef CONFIG_OF
904 static const struct of_device_id mv_xor_v2_dt_ids[] = {
905 	{ .compatible = "marvell,xor-v2", },
906 	{},
907 };
908 MODULE_DEVICE_TABLE(of, mv_xor_v2_dt_ids);
909 #endif
910 
911 static struct platform_driver mv_xor_v2_driver = {
912 	.probe		= mv_xor_v2_probe,
913 	.suspend	= mv_xor_v2_suspend,
914 	.resume		= mv_xor_v2_resume,
915 	.remove		= mv_xor_v2_remove,
916 	.driver		= {
917 		.name	= "mv_xor_v2",
918 		.of_match_table = of_match_ptr(mv_xor_v2_dt_ids),
919 	},
920 };
921 
922 module_platform_driver(mv_xor_v2_driver);
923 
924 MODULE_DESCRIPTION("DMA engine driver for Marvell's Version 2 of XOR engine");
925 MODULE_LICENSE("GPL");
926