xref: /openbmc/linux/drivers/dma/mv_xor_v2.c (revision 0a94608f)
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  * @clk: reference to the 'core' clock
139  * @reg_clk: reference to the 'reg' clock
140  * @dma_base: memory mapped DMA register base
141  * @glob_base: memory mapped global register base
142  * @irq_tasklet: tasklet used for IRQ handling call-backs
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  * @hw_queue_idx: HW queue index
152  * @irq: The Linux interrupt number
153  * been called, but not yet issue_pending)
154  */
155 struct mv_xor_v2_device {
156 	spinlock_t lock;
157 	void __iomem *dma_base;
158 	void __iomem *glob_base;
159 	struct clk *clk;
160 	struct clk *reg_clk;
161 	struct tasklet_struct irq_tasklet;
162 	struct list_head free_sw_desc;
163 	struct dma_device dmadev;
164 	struct dma_chan	dmachan;
165 	dma_addr_t hw_desq;
166 	struct mv_xor_v2_descriptor *hw_desq_virt;
167 	struct mv_xor_v2_sw_desc *sw_desq;
168 	int desc_size;
169 	unsigned int npendings;
170 	unsigned int hw_queue_idx;
171 	unsigned int irq;
172 };
173 
174 /**
175  * struct mv_xor_v2_sw_desc - implements a xor SW descriptor
176  * @idx: descriptor index
177  * @async_tx: support for the async_tx api
178  * @hw_desc: assosiated HW descriptor
179  * @free_list: node of the free SW descriprots list
180 */
181 struct mv_xor_v2_sw_desc {
182 	int idx;
183 	struct dma_async_tx_descriptor async_tx;
184 	struct mv_xor_v2_descriptor hw_desc;
185 	struct list_head free_list;
186 };
187 
188 /*
189  * Fill the data buffers to a HW descriptor
190  */
191 static void mv_xor_v2_set_data_buffers(struct mv_xor_v2_device *xor_dev,
192 					struct mv_xor_v2_descriptor *desc,
193 					dma_addr_t src, int index)
194 {
195 	int arr_index = ((index >> 1) * 3);
196 
197 	/*
198 	 * Fill the buffer's addresses to the descriptor.
199 	 *
200 	 * The format of the buffers address for 2 sequential buffers
201 	 * X and X + 1:
202 	 *
203 	 *  First word:  Buffer-DX-Address-Low[31:0]
204 	 *  Second word: Buffer-DX+1-Address-Low[31:0]
205 	 *  Third word:  DX+1-Buffer-Address-High[47:32] [31:16]
206 	 *		 DX-Buffer-Address-High[47:32] [15:0]
207 	 */
208 	if ((index & 0x1) == 0) {
209 		desc->data_buff_addr[arr_index] = lower_32_bits(src);
210 
211 		desc->data_buff_addr[arr_index + 2] &= ~0xFFFF;
212 		desc->data_buff_addr[arr_index + 2] |=
213 			upper_32_bits(src) & 0xFFFF;
214 	} else {
215 		desc->data_buff_addr[arr_index + 1] =
216 			lower_32_bits(src);
217 
218 		desc->data_buff_addr[arr_index + 2] &= ~0xFFFF0000;
219 		desc->data_buff_addr[arr_index + 2] |=
220 			(upper_32_bits(src) & 0xFFFF) << 16;
221 	}
222 }
223 
224 /*
225  * notify the engine of new descriptors, and update the available index.
226  */
227 static void mv_xor_v2_add_desc_to_desq(struct mv_xor_v2_device *xor_dev,
228 				       int num_of_desc)
229 {
230 	/* write the number of new descriptors in the DESQ. */
231 	writel(num_of_desc, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_ADD_OFF);
232 }
233 
234 /*
235  * free HW descriptors
236  */
237 static void mv_xor_v2_free_desc_from_desq(struct mv_xor_v2_device *xor_dev,
238 					  int num_of_desc)
239 {
240 	/* write the number of new descriptors in the DESQ. */
241 	writel(num_of_desc, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_DEALLOC_OFF);
242 }
243 
244 /*
245  * Set descriptor size
246  * Return the HW descriptor size in bytes
247  */
248 static int mv_xor_v2_set_desc_size(struct mv_xor_v2_device *xor_dev)
249 {
250 	writel(MV_XOR_V2_DMA_DESQ_CTRL_128B,
251 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_CTRL_OFF);
252 
253 	return MV_XOR_V2_EXT_DESC_SIZE;
254 }
255 
256 /*
257  * Set the IMSG threshold
258  */
259 static inline
260 void mv_xor_v2_enable_imsg_thrd(struct mv_xor_v2_device *xor_dev)
261 {
262 	u32 reg;
263 
264 	/* Configure threshold of number of descriptors, and enable timer */
265 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
266 	reg &= ~MV_XOR_V2_DMA_IMSG_THRD_MASK;
267 	reg |= MV_XOR_V2_DONE_IMSG_THRD;
268 	reg |= MV_XOR_V2_DMA_IMSG_TIMER_EN;
269 	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
270 
271 	/* Configure Timer Threshold */
272 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_TMOT);
273 	reg &= ~MV_XOR_V2_DMA_IMSG_TIMER_THRD_MASK;
274 	reg |= MV_XOR_V2_TIMER_THRD;
275 	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_TMOT);
276 }
277 
278 static irqreturn_t mv_xor_v2_interrupt_handler(int irq, void *data)
279 {
280 	struct mv_xor_v2_device *xor_dev = data;
281 	unsigned int ndescs;
282 	u32 reg;
283 
284 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_DONE_OFF);
285 
286 	ndescs = ((reg >> MV_XOR_V2_DMA_DESQ_DONE_PENDING_SHIFT) &
287 		  MV_XOR_V2_DMA_DESQ_DONE_PENDING_MASK);
288 
289 	/* No descriptors to process */
290 	if (!ndescs)
291 		return IRQ_NONE;
292 
293 	/* schedule a tasklet to handle descriptors callbacks */
294 	tasklet_schedule(&xor_dev->irq_tasklet);
295 
296 	return IRQ_HANDLED;
297 }
298 
299 /*
300  * submit a descriptor to the DMA engine
301  */
302 static dma_cookie_t
303 mv_xor_v2_tx_submit(struct dma_async_tx_descriptor *tx)
304 {
305 	void *dest_hw_desc;
306 	dma_cookie_t cookie;
307 	struct mv_xor_v2_sw_desc *sw_desc =
308 		container_of(tx, struct mv_xor_v2_sw_desc, async_tx);
309 	struct mv_xor_v2_device *xor_dev =
310 		container_of(tx->chan, struct mv_xor_v2_device, dmachan);
311 
312 	dev_dbg(xor_dev->dmadev.dev,
313 		"%s sw_desc %p: async_tx %p\n",
314 		__func__, sw_desc, &sw_desc->async_tx);
315 
316 	/* assign coookie */
317 	spin_lock_bh(&xor_dev->lock);
318 	cookie = dma_cookie_assign(tx);
319 
320 	/* copy the HW descriptor from the SW descriptor to the DESQ */
321 	dest_hw_desc = xor_dev->hw_desq_virt + xor_dev->hw_queue_idx;
322 
323 	memcpy(dest_hw_desc, &sw_desc->hw_desc, xor_dev->desc_size);
324 
325 	xor_dev->npendings++;
326 	xor_dev->hw_queue_idx++;
327 	if (xor_dev->hw_queue_idx >= MV_XOR_V2_DESC_NUM)
328 		xor_dev->hw_queue_idx = 0;
329 
330 	spin_unlock_bh(&xor_dev->lock);
331 
332 	return cookie;
333 }
334 
335 /*
336  * Prepare a SW descriptor
337  */
338 static struct mv_xor_v2_sw_desc	*
339 mv_xor_v2_prep_sw_desc(struct mv_xor_v2_device *xor_dev)
340 {
341 	struct mv_xor_v2_sw_desc *sw_desc;
342 	bool found = false;
343 
344 	/* Lock the channel */
345 	spin_lock_bh(&xor_dev->lock);
346 
347 	if (list_empty(&xor_dev->free_sw_desc)) {
348 		spin_unlock_bh(&xor_dev->lock);
349 		/* schedule tasklet to free some descriptors */
350 		tasklet_schedule(&xor_dev->irq_tasklet);
351 		return NULL;
352 	}
353 
354 	list_for_each_entry(sw_desc, &xor_dev->free_sw_desc, free_list) {
355 		if (async_tx_test_ack(&sw_desc->async_tx)) {
356 			found = true;
357 			break;
358 		}
359 	}
360 
361 	if (!found) {
362 		spin_unlock_bh(&xor_dev->lock);
363 		return NULL;
364 	}
365 
366 	list_del(&sw_desc->free_list);
367 
368 	/* Release the channel */
369 	spin_unlock_bh(&xor_dev->lock);
370 
371 	return sw_desc;
372 }
373 
374 /*
375  * Prepare a HW descriptor for a memcpy operation
376  */
377 static struct dma_async_tx_descriptor *
378 mv_xor_v2_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest,
379 			  dma_addr_t src, size_t len, unsigned long flags)
380 {
381 	struct mv_xor_v2_sw_desc *sw_desc;
382 	struct mv_xor_v2_descriptor *hw_descriptor;
383 	struct mv_xor_v2_device	*xor_dev;
384 
385 	xor_dev = container_of(chan, struct mv_xor_v2_device, dmachan);
386 
387 	dev_dbg(xor_dev->dmadev.dev,
388 		"%s len: %zu src %pad dest %pad flags: %ld\n",
389 		__func__, len, &src, &dest, flags);
390 
391 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
392 	if (!sw_desc)
393 		return NULL;
394 
395 	sw_desc->async_tx.flags = flags;
396 
397 	/* set the HW descriptor */
398 	hw_descriptor = &sw_desc->hw_desc;
399 
400 	/* save the SW descriptor ID to restore when operation is done */
401 	hw_descriptor->desc_id = sw_desc->idx;
402 
403 	/* Set the MEMCPY control word */
404 	hw_descriptor->desc_ctrl =
405 		DESC_OP_MODE_MEMCPY << DESC_OP_MODE_SHIFT;
406 
407 	if (flags & DMA_PREP_INTERRUPT)
408 		hw_descriptor->desc_ctrl |= DESC_IOD;
409 
410 	/* Set source address */
411 	hw_descriptor->fill_pattern_src_addr[0] = lower_32_bits(src);
412 	hw_descriptor->fill_pattern_src_addr[1] =
413 		upper_32_bits(src) & 0xFFFF;
414 
415 	/* Set Destination address */
416 	hw_descriptor->fill_pattern_src_addr[2] = lower_32_bits(dest);
417 	hw_descriptor->fill_pattern_src_addr[3] =
418 		upper_32_bits(dest) & 0xFFFF;
419 
420 	/* Set buffers size */
421 	hw_descriptor->buff_size = len;
422 
423 	/* return the async tx descriptor */
424 	return &sw_desc->async_tx;
425 }
426 
427 /*
428  * Prepare a HW descriptor for a XOR operation
429  */
430 static struct dma_async_tx_descriptor *
431 mv_xor_v2_prep_dma_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
432 		       unsigned int src_cnt, size_t len, unsigned long flags)
433 {
434 	struct mv_xor_v2_sw_desc *sw_desc;
435 	struct mv_xor_v2_descriptor *hw_descriptor;
436 	struct mv_xor_v2_device	*xor_dev =
437 		container_of(chan, struct mv_xor_v2_device, dmachan);
438 	int i;
439 
440 	if (src_cnt > MV_XOR_V2_CMD_LINE_NUM_MAX_D_BUF || src_cnt < 1)
441 		return NULL;
442 
443 	dev_dbg(xor_dev->dmadev.dev,
444 		"%s src_cnt: %d len: %zu dest %pad flags: %ld\n",
445 		__func__, src_cnt, len, &dest, flags);
446 
447 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
448 	if (!sw_desc)
449 		return NULL;
450 
451 	sw_desc->async_tx.flags = flags;
452 
453 	/* set the HW descriptor */
454 	hw_descriptor = &sw_desc->hw_desc;
455 
456 	/* save the SW descriptor ID to restore when operation is done */
457 	hw_descriptor->desc_id = sw_desc->idx;
458 
459 	/* Set the XOR control word */
460 	hw_descriptor->desc_ctrl =
461 		DESC_OP_MODE_XOR << DESC_OP_MODE_SHIFT;
462 	hw_descriptor->desc_ctrl |= DESC_P_BUFFER_ENABLE;
463 
464 	if (flags & DMA_PREP_INTERRUPT)
465 		hw_descriptor->desc_ctrl |= DESC_IOD;
466 
467 	/* Set the data buffers */
468 	for (i = 0; i < src_cnt; i++)
469 		mv_xor_v2_set_data_buffers(xor_dev, hw_descriptor, src[i], i);
470 
471 	hw_descriptor->desc_ctrl |=
472 		src_cnt << DESC_NUM_ACTIVE_D_BUF_SHIFT;
473 
474 	/* Set Destination address */
475 	hw_descriptor->fill_pattern_src_addr[2] = lower_32_bits(dest);
476 	hw_descriptor->fill_pattern_src_addr[3] =
477 		upper_32_bits(dest) & 0xFFFF;
478 
479 	/* Set buffers size */
480 	hw_descriptor->buff_size = len;
481 
482 	/* return the async tx descriptor */
483 	return &sw_desc->async_tx;
484 }
485 
486 /*
487  * Prepare a HW descriptor for interrupt operation.
488  */
489 static struct dma_async_tx_descriptor *
490 mv_xor_v2_prep_dma_interrupt(struct dma_chan *chan, unsigned long flags)
491 {
492 	struct mv_xor_v2_sw_desc *sw_desc;
493 	struct mv_xor_v2_descriptor *hw_descriptor;
494 	struct mv_xor_v2_device	*xor_dev =
495 		container_of(chan, struct mv_xor_v2_device, dmachan);
496 
497 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
498 	if (!sw_desc)
499 		return NULL;
500 
501 	/* set the HW descriptor */
502 	hw_descriptor = &sw_desc->hw_desc;
503 
504 	/* save the SW descriptor ID to restore when operation is done */
505 	hw_descriptor->desc_id = sw_desc->idx;
506 
507 	/* Set the INTERRUPT control word */
508 	hw_descriptor->desc_ctrl =
509 		DESC_OP_MODE_NOP << DESC_OP_MODE_SHIFT;
510 	hw_descriptor->desc_ctrl |= DESC_IOD;
511 
512 	/* return the async tx descriptor */
513 	return &sw_desc->async_tx;
514 }
515 
516 /*
517  * push pending transactions to hardware
518  */
519 static void mv_xor_v2_issue_pending(struct dma_chan *chan)
520 {
521 	struct mv_xor_v2_device *xor_dev =
522 		container_of(chan, struct mv_xor_v2_device, dmachan);
523 
524 	spin_lock_bh(&xor_dev->lock);
525 
526 	/*
527 	 * update the engine with the number of descriptors to
528 	 * process
529 	 */
530 	mv_xor_v2_add_desc_to_desq(xor_dev, xor_dev->npendings);
531 	xor_dev->npendings = 0;
532 
533 	spin_unlock_bh(&xor_dev->lock);
534 }
535 
536 static inline
537 int mv_xor_v2_get_pending_params(struct mv_xor_v2_device *xor_dev,
538 				 int *pending_ptr)
539 {
540 	u32 reg;
541 
542 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_DONE_OFF);
543 
544 	/* get the next pending descriptor index */
545 	*pending_ptr = ((reg >> MV_XOR_V2_DMA_DESQ_DONE_READ_PTR_SHIFT) &
546 			MV_XOR_V2_DMA_DESQ_DONE_READ_PTR_MASK);
547 
548 	/* get the number of descriptors pending handle */
549 	return ((reg >> MV_XOR_V2_DMA_DESQ_DONE_PENDING_SHIFT) &
550 		MV_XOR_V2_DMA_DESQ_DONE_PENDING_MASK);
551 }
552 
553 /*
554  * handle the descriptors after HW process
555  */
556 static void mv_xor_v2_tasklet(struct tasklet_struct *t)
557 {
558 	struct mv_xor_v2_device *xor_dev = from_tasklet(xor_dev, t,
559 							irq_tasklet);
560 	int pending_ptr, num_of_pending, i;
561 	struct mv_xor_v2_sw_desc *next_pending_sw_desc = NULL;
562 
563 	dev_dbg(xor_dev->dmadev.dev, "%s %d\n", __func__, __LINE__);
564 
565 	/* get the pending descriptors parameters */
566 	num_of_pending = mv_xor_v2_get_pending_params(xor_dev, &pending_ptr);
567 
568 	/* loop over free descriptors */
569 	for (i = 0; i < num_of_pending; i++) {
570 		struct mv_xor_v2_descriptor *next_pending_hw_desc =
571 			xor_dev->hw_desq_virt + pending_ptr;
572 
573 		/* get the SW descriptor related to the HW descriptor */
574 		next_pending_sw_desc =
575 			&xor_dev->sw_desq[next_pending_hw_desc->desc_id];
576 
577 		/* call the callback */
578 		if (next_pending_sw_desc->async_tx.cookie > 0) {
579 			/*
580 			 * update the channel's completed cookie - no
581 			 * lock is required the IMSG threshold provide
582 			 * the locking
583 			 */
584 			dma_cookie_complete(&next_pending_sw_desc->async_tx);
585 
586 			dma_descriptor_unmap(&next_pending_sw_desc->async_tx);
587 			dmaengine_desc_get_callback_invoke(
588 					&next_pending_sw_desc->async_tx, NULL);
589 		}
590 
591 		dma_run_dependencies(&next_pending_sw_desc->async_tx);
592 
593 		/* Lock the channel */
594 		spin_lock_bh(&xor_dev->lock);
595 
596 		/* add the SW descriptor to the free descriptors list */
597 		list_add(&next_pending_sw_desc->free_list,
598 			 &xor_dev->free_sw_desc);
599 
600 		/* Release the channel */
601 		spin_unlock_bh(&xor_dev->lock);
602 
603 		/* increment the next descriptor */
604 		pending_ptr++;
605 		if (pending_ptr >= MV_XOR_V2_DESC_NUM)
606 			pending_ptr = 0;
607 	}
608 
609 	if (num_of_pending != 0) {
610 		/* free the descriptores */
611 		mv_xor_v2_free_desc_from_desq(xor_dev, num_of_pending);
612 	}
613 }
614 
615 /*
616  *	Set DMA Interrupt-message (IMSG) parameters
617  */
618 static void mv_xor_v2_set_msi_msg(struct msi_desc *desc, struct msi_msg *msg)
619 {
620 	struct mv_xor_v2_device *xor_dev = dev_get_drvdata(desc->dev);
621 
622 	writel(msg->address_lo,
623 	       xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_BALR_OFF);
624 	writel(msg->address_hi & 0xFFFF,
625 	       xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_BAHR_OFF);
626 	writel(msg->data,
627 	       xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_CDAT_OFF);
628 }
629 
630 static int mv_xor_v2_descq_init(struct mv_xor_v2_device *xor_dev)
631 {
632 	u32 reg;
633 
634 	/* write the DESQ size to the DMA engine */
635 	writel(MV_XOR_V2_DESC_NUM,
636 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_SIZE_OFF);
637 
638 	/* write the DESQ address to the DMA enngine*/
639 	writel(lower_32_bits(xor_dev->hw_desq),
640 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_BALR_OFF);
641 	writel(upper_32_bits(xor_dev->hw_desq),
642 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_BAHR_OFF);
643 
644 	/*
645 	 * This is a temporary solution, until we activate the
646 	 * SMMU. Set the attributes for reading & writing data buffers
647 	 * & descriptors to:
648 	 *
649 	 *  - OuterShareable - Snoops will be performed on CPU caches
650 	 *  - Enable cacheable - Bufferable, Modifiable, Other Allocate
651 	 *    and Allocate
652 	 */
653 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_ARATTR_OFF);
654 	reg &= ~MV_XOR_V2_DMA_DESQ_ATTR_CACHE_MASK;
655 	reg |= MV_XOR_V2_DMA_DESQ_ATTR_OUTER_SHAREABLE |
656 		MV_XOR_V2_DMA_DESQ_ATTR_CACHEABLE;
657 	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_ARATTR_OFF);
658 
659 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_AWATTR_OFF);
660 	reg &= ~MV_XOR_V2_DMA_DESQ_ATTR_CACHE_MASK;
661 	reg |= MV_XOR_V2_DMA_DESQ_ATTR_OUTER_SHAREABLE |
662 		MV_XOR_V2_DMA_DESQ_ATTR_CACHEABLE;
663 	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_AWATTR_OFF);
664 
665 	/* BW CTRL - set values to optimize the XOR performance:
666 	 *
667 	 *  - Set WrBurstLen & RdBurstLen - the unit will issue
668 	 *    maximum of 256B write/read transactions.
669 	 * -  Limit the number of outstanding write & read data
670 	 *    (OBB/IBB) requests to the maximal value.
671 	*/
672 	reg = ((MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_RD_VAL <<
673 		MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_RD_SHIFT) |
674 	       (MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_WR_VAL  <<
675 		MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_WR_SHIFT) |
676 	       (MV_XOR_V2_GLOB_BW_CTRL_RD_BURST_LEN_VAL <<
677 		MV_XOR_V2_GLOB_BW_CTRL_RD_BURST_LEN_SHIFT) |
678 	       (MV_XOR_V2_GLOB_BW_CTRL_WR_BURST_LEN_VAL <<
679 		MV_XOR_V2_GLOB_BW_CTRL_WR_BURST_LEN_SHIFT));
680 	writel(reg, xor_dev->glob_base + MV_XOR_V2_GLOB_BW_CTRL);
681 
682 	/* Disable the AXI timer feature */
683 	reg = readl(xor_dev->glob_base + MV_XOR_V2_GLOB_PAUSE);
684 	reg |= MV_XOR_V2_GLOB_PAUSE_AXI_TIME_DIS_VAL;
685 	writel(reg, xor_dev->glob_base + MV_XOR_V2_GLOB_PAUSE);
686 
687 	/* enable the DMA engine */
688 	writel(0, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_STOP_OFF);
689 
690 	return 0;
691 }
692 
693 static int mv_xor_v2_suspend(struct platform_device *dev, pm_message_t state)
694 {
695 	struct mv_xor_v2_device *xor_dev = platform_get_drvdata(dev);
696 
697 	/* Set this bit to disable to stop the XOR unit. */
698 	writel(0x1, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_STOP_OFF);
699 
700 	return 0;
701 }
702 
703 static int mv_xor_v2_resume(struct platform_device *dev)
704 {
705 	struct mv_xor_v2_device *xor_dev = platform_get_drvdata(dev);
706 
707 	mv_xor_v2_set_desc_size(xor_dev);
708 	mv_xor_v2_enable_imsg_thrd(xor_dev);
709 	mv_xor_v2_descq_init(xor_dev);
710 
711 	return 0;
712 }
713 
714 static int mv_xor_v2_probe(struct platform_device *pdev)
715 {
716 	struct mv_xor_v2_device *xor_dev;
717 	struct resource *res;
718 	int i, ret = 0;
719 	struct dma_device *dma_dev;
720 	struct mv_xor_v2_sw_desc *sw_desc;
721 
722 	BUILD_BUG_ON(sizeof(struct mv_xor_v2_descriptor) !=
723 		     MV_XOR_V2_EXT_DESC_SIZE);
724 
725 	xor_dev = devm_kzalloc(&pdev->dev, sizeof(*xor_dev), GFP_KERNEL);
726 	if (!xor_dev)
727 		return -ENOMEM;
728 
729 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
730 	xor_dev->dma_base = devm_ioremap_resource(&pdev->dev, res);
731 	if (IS_ERR(xor_dev->dma_base))
732 		return PTR_ERR(xor_dev->dma_base);
733 
734 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
735 	xor_dev->glob_base = devm_ioremap_resource(&pdev->dev, res);
736 	if (IS_ERR(xor_dev->glob_base))
737 		return PTR_ERR(xor_dev->glob_base);
738 
739 	platform_set_drvdata(pdev, xor_dev);
740 
741 	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40));
742 	if (ret)
743 		return ret;
744 
745 	xor_dev->reg_clk = devm_clk_get(&pdev->dev, "reg");
746 	if (PTR_ERR(xor_dev->reg_clk) != -ENOENT) {
747 		if (!IS_ERR(xor_dev->reg_clk)) {
748 			ret = clk_prepare_enable(xor_dev->reg_clk);
749 			if (ret)
750 				return ret;
751 		} else {
752 			return PTR_ERR(xor_dev->reg_clk);
753 		}
754 	}
755 
756 	xor_dev->clk = devm_clk_get(&pdev->dev, NULL);
757 	if (PTR_ERR(xor_dev->clk) == -EPROBE_DEFER) {
758 		ret = EPROBE_DEFER;
759 		goto disable_reg_clk;
760 	}
761 	if (!IS_ERR(xor_dev->clk)) {
762 		ret = clk_prepare_enable(xor_dev->clk);
763 		if (ret)
764 			goto disable_reg_clk;
765 	}
766 
767 	ret = platform_msi_domain_alloc_irqs(&pdev->dev, 1,
768 					     mv_xor_v2_set_msi_msg);
769 	if (ret)
770 		goto disable_clk;
771 
772 	xor_dev->irq = msi_get_virq(&pdev->dev, 0);
773 
774 	ret = devm_request_irq(&pdev->dev, xor_dev->irq,
775 			       mv_xor_v2_interrupt_handler, 0,
776 			       dev_name(&pdev->dev), xor_dev);
777 	if (ret)
778 		goto free_msi_irqs;
779 
780 	tasklet_setup(&xor_dev->irq_tasklet, mv_xor_v2_tasklet);
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->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