xref: /openbmc/linux/drivers/dma/mv_xor_v2.c (revision ebd09753)
1 /*
2  * Copyright (C) 2015-2016 Marvell International Ltd.
3 
4  * This program is free software: you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation, either version 2 of the
7  * License, or any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * General Public License for more details.
13  */
14 
15 #include <linux/clk.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/interrupt.h>
18 #include <linux/io.h>
19 #include <linux/module.h>
20 #include <linux/msi.h>
21 #include <linux/of.h>
22 #include <linux/of_irq.h>
23 #include <linux/platform_device.h>
24 #include <linux/spinlock.h>
25 
26 #include "dmaengine.h"
27 
28 /* DMA Engine Registers */
29 #define MV_XOR_V2_DMA_DESQ_BALR_OFF			0x000
30 #define MV_XOR_V2_DMA_DESQ_BAHR_OFF			0x004
31 #define MV_XOR_V2_DMA_DESQ_SIZE_OFF			0x008
32 #define MV_XOR_V2_DMA_DESQ_DONE_OFF			0x00C
33 #define   MV_XOR_V2_DMA_DESQ_DONE_PENDING_MASK		0x7FFF
34 #define   MV_XOR_V2_DMA_DESQ_DONE_PENDING_SHIFT		0
35 #define   MV_XOR_V2_DMA_DESQ_DONE_READ_PTR_MASK		0x1FFF
36 #define   MV_XOR_V2_DMA_DESQ_DONE_READ_PTR_SHIFT	16
37 #define MV_XOR_V2_DMA_DESQ_ARATTR_OFF			0x010
38 #define   MV_XOR_V2_DMA_DESQ_ATTR_CACHE_MASK		0x3F3F
39 #define   MV_XOR_V2_DMA_DESQ_ATTR_OUTER_SHAREABLE	0x202
40 #define   MV_XOR_V2_DMA_DESQ_ATTR_CACHEABLE		0x3C3C
41 #define MV_XOR_V2_DMA_IMSG_CDAT_OFF			0x014
42 #define MV_XOR_V2_DMA_IMSG_THRD_OFF			0x018
43 #define   MV_XOR_V2_DMA_IMSG_THRD_MASK			0x7FFF
44 #define   MV_XOR_V2_DMA_IMSG_THRD_SHIFT			0x0
45 #define   MV_XOR_V2_DMA_IMSG_TIMER_EN			BIT(18)
46 #define MV_XOR_V2_DMA_DESQ_AWATTR_OFF			0x01C
47   /* Same flags as MV_XOR_V2_DMA_DESQ_ARATTR_OFF */
48 #define MV_XOR_V2_DMA_DESQ_ALLOC_OFF			0x04C
49 #define   MV_XOR_V2_DMA_DESQ_ALLOC_WRPTR_MASK		0xFFFF
50 #define   MV_XOR_V2_DMA_DESQ_ALLOC_WRPTR_SHIFT		16
51 #define MV_XOR_V2_DMA_IMSG_BALR_OFF			0x050
52 #define MV_XOR_V2_DMA_IMSG_BAHR_OFF			0x054
53 #define MV_XOR_V2_DMA_DESQ_CTRL_OFF			0x100
54 #define	  MV_XOR_V2_DMA_DESQ_CTRL_32B			1
55 #define   MV_XOR_V2_DMA_DESQ_CTRL_128B			7
56 #define MV_XOR_V2_DMA_DESQ_STOP_OFF			0x800
57 #define MV_XOR_V2_DMA_DESQ_DEALLOC_OFF			0x804
58 #define MV_XOR_V2_DMA_DESQ_ADD_OFF			0x808
59 #define MV_XOR_V2_DMA_IMSG_TMOT				0x810
60 #define   MV_XOR_V2_DMA_IMSG_TIMER_THRD_MASK		0x1FFF
61 #define   MV_XOR_V2_DMA_IMSG_TIMER_THRD_SHIFT		0
62 
63 /* XOR Global registers */
64 #define MV_XOR_V2_GLOB_BW_CTRL				0x4
65 #define   MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_RD_SHIFT	0
66 #define   MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_RD_VAL	64
67 #define   MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_WR_SHIFT	8
68 #define   MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_WR_VAL	8
69 #define   MV_XOR_V2_GLOB_BW_CTRL_RD_BURST_LEN_SHIFT	12
70 #define   MV_XOR_V2_GLOB_BW_CTRL_RD_BURST_LEN_VAL	4
71 #define   MV_XOR_V2_GLOB_BW_CTRL_WR_BURST_LEN_SHIFT	16
72 #define	  MV_XOR_V2_GLOB_BW_CTRL_WR_BURST_LEN_VAL	4
73 #define MV_XOR_V2_GLOB_PAUSE				0x014
74 #define   MV_XOR_V2_GLOB_PAUSE_AXI_TIME_DIS_VAL		0x8
75 #define MV_XOR_V2_GLOB_SYS_INT_CAUSE			0x200
76 #define MV_XOR_V2_GLOB_SYS_INT_MASK			0x204
77 #define MV_XOR_V2_GLOB_MEM_INT_CAUSE			0x220
78 #define MV_XOR_V2_GLOB_MEM_INT_MASK			0x224
79 
80 #define MV_XOR_V2_MIN_DESC_SIZE				32
81 #define MV_XOR_V2_EXT_DESC_SIZE				128
82 
83 #define MV_XOR_V2_DESC_RESERVED_SIZE			12
84 #define MV_XOR_V2_DESC_BUFF_D_ADDR_SIZE			12
85 
86 #define MV_XOR_V2_CMD_LINE_NUM_MAX_D_BUF		8
87 
88 /*
89  * Descriptors queue size. With 32 bytes descriptors, up to 2^14
90  * descriptors are allowed, with 128 bytes descriptors, up to 2^12
91  * descriptors are allowed. This driver uses 128 bytes descriptors,
92  * but experimentation has shown that a set of 1024 descriptors is
93  * sufficient to reach a good level of performance.
94  */
95 #define MV_XOR_V2_DESC_NUM				1024
96 
97 /*
98  * Threshold values for descriptors and timeout, determined by
99  * experimentation as giving a good level of performance.
100  */
101 #define MV_XOR_V2_DONE_IMSG_THRD  0x14
102 #define MV_XOR_V2_TIMER_THRD      0xB0
103 
104 /**
105  * struct mv_xor_v2_descriptor - DMA HW descriptor
106  * @desc_id: used by S/W and is not affected by H/W.
107  * @flags: error and status flags
108  * @crc32_result: CRC32 calculation result
109  * @desc_ctrl: operation mode and control flags
110  * @buff_size: amount of bytes to be processed
111  * @fill_pattern_src_addr: Fill-Pattern or Source-Address and
112  * AW-Attributes
113  * @data_buff_addr: Source (and might be RAID6 destination)
114  * addresses of data buffers in RAID5 and RAID6
115  * @reserved: reserved
116  */
117 struct mv_xor_v2_descriptor {
118 	u16 desc_id;
119 	u16 flags;
120 	u32 crc32_result;
121 	u32 desc_ctrl;
122 
123 	/* Definitions for desc_ctrl */
124 #define DESC_NUM_ACTIVE_D_BUF_SHIFT	22
125 #define DESC_OP_MODE_SHIFT		28
126 #define DESC_OP_MODE_NOP		0	/* Idle operation */
127 #define DESC_OP_MODE_MEMCPY		1	/* Pure-DMA operation */
128 #define DESC_OP_MODE_MEMSET		2	/* Mem-Fill operation */
129 #define DESC_OP_MODE_MEMINIT		3	/* Mem-Init operation */
130 #define DESC_OP_MODE_MEM_COMPARE	4	/* Mem-Compare operation */
131 #define DESC_OP_MODE_CRC32		5	/* CRC32 calculation */
132 #define DESC_OP_MODE_XOR		6	/* RAID5 (XOR) operation */
133 #define DESC_OP_MODE_RAID6		7	/* RAID6 P&Q-generation */
134 #define DESC_OP_MODE_RAID6_REC		8	/* RAID6 Recovery */
135 #define DESC_Q_BUFFER_ENABLE		BIT(16)
136 #define DESC_P_BUFFER_ENABLE		BIT(17)
137 #define DESC_IOD			BIT(27)
138 
139 	u32 buff_size;
140 	u32 fill_pattern_src_addr[4];
141 	u32 data_buff_addr[MV_XOR_V2_DESC_BUFF_D_ADDR_SIZE];
142 	u32 reserved[MV_XOR_V2_DESC_RESERVED_SIZE];
143 };
144 
145 /**
146  * struct mv_xor_v2_device - implements a xor device
147  * @lock: lock for the engine
148  * @dma_base: memory mapped DMA register base
149  * @glob_base: memory mapped global register base
150  * @irq_tasklet:
151  * @free_sw_desc: linked list of free SW descriptors
152  * @dmadev: dma device
153  * @dmachan: dma channel
154  * @hw_desq: HW descriptors queue
155  * @hw_desq_virt: virtual address of DESCQ
156  * @sw_desq: SW descriptors queue
157  * @desc_size: HW descriptor size
158  * @npendings: number of pending descriptors (for which tx_submit has
159  * been called, but not yet issue_pending)
160  */
161 struct mv_xor_v2_device {
162 	spinlock_t lock;
163 	void __iomem *dma_base;
164 	void __iomem *glob_base;
165 	struct clk *clk;
166 	struct clk *reg_clk;
167 	struct tasklet_struct irq_tasklet;
168 	struct list_head free_sw_desc;
169 	struct dma_device dmadev;
170 	struct dma_chan	dmachan;
171 	dma_addr_t hw_desq;
172 	struct mv_xor_v2_descriptor *hw_desq_virt;
173 	struct mv_xor_v2_sw_desc *sw_desq;
174 	int desc_size;
175 	unsigned int npendings;
176 	unsigned int hw_queue_idx;
177 	struct msi_desc *msi_desc;
178 };
179 
180 /**
181  * struct mv_xor_v2_sw_desc - implements a xor SW descriptor
182  * @idx: descriptor index
183  * @async_tx: support for the async_tx api
184  * @hw_desc: assosiated HW descriptor
185  * @free_list: node of the free SW descriprots list
186 */
187 struct mv_xor_v2_sw_desc {
188 	int idx;
189 	struct dma_async_tx_descriptor async_tx;
190 	struct mv_xor_v2_descriptor hw_desc;
191 	struct list_head free_list;
192 };
193 
194 /*
195  * Fill the data buffers to a HW descriptor
196  */
197 static void mv_xor_v2_set_data_buffers(struct mv_xor_v2_device *xor_dev,
198 					struct mv_xor_v2_descriptor *desc,
199 					dma_addr_t src, int index)
200 {
201 	int arr_index = ((index >> 1) * 3);
202 
203 	/*
204 	 * Fill the buffer's addresses to the descriptor.
205 	 *
206 	 * The format of the buffers address for 2 sequential buffers
207 	 * X and X + 1:
208 	 *
209 	 *  First word:  Buffer-DX-Address-Low[31:0]
210 	 *  Second word: Buffer-DX+1-Address-Low[31:0]
211 	 *  Third word:  DX+1-Buffer-Address-High[47:32] [31:16]
212 	 *		 DX-Buffer-Address-High[47:32] [15:0]
213 	 */
214 	if ((index & 0x1) == 0) {
215 		desc->data_buff_addr[arr_index] = lower_32_bits(src);
216 
217 		desc->data_buff_addr[arr_index + 2] &= ~0xFFFF;
218 		desc->data_buff_addr[arr_index + 2] |=
219 			upper_32_bits(src) & 0xFFFF;
220 	} else {
221 		desc->data_buff_addr[arr_index + 1] =
222 			lower_32_bits(src);
223 
224 		desc->data_buff_addr[arr_index + 2] &= ~0xFFFF0000;
225 		desc->data_buff_addr[arr_index + 2] |=
226 			(upper_32_bits(src) & 0xFFFF) << 16;
227 	}
228 }
229 
230 /*
231  * notify the engine of new descriptors, and update the available index.
232  */
233 static void mv_xor_v2_add_desc_to_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_ADD_OFF);
238 }
239 
240 /*
241  * free HW descriptors
242  */
243 static void mv_xor_v2_free_desc_from_desq(struct mv_xor_v2_device *xor_dev,
244 					  int num_of_desc)
245 {
246 	/* write the number of new descriptors in the DESQ. */
247 	writel(num_of_desc, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_DEALLOC_OFF);
248 }
249 
250 /*
251  * Set descriptor size
252  * Return the HW descriptor size in bytes
253  */
254 static int mv_xor_v2_set_desc_size(struct mv_xor_v2_device *xor_dev)
255 {
256 	writel(MV_XOR_V2_DMA_DESQ_CTRL_128B,
257 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_CTRL_OFF);
258 
259 	return MV_XOR_V2_EXT_DESC_SIZE;
260 }
261 
262 /*
263  * Set the IMSG threshold
264  */
265 static inline
266 void mv_xor_v2_enable_imsg_thrd(struct mv_xor_v2_device *xor_dev)
267 {
268 	u32 reg;
269 
270 	/* Configure threshold of number of descriptors, and enable timer */
271 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
272 	reg &= (~MV_XOR_V2_DMA_IMSG_THRD_MASK << MV_XOR_V2_DMA_IMSG_THRD_SHIFT);
273 	reg |= (MV_XOR_V2_DONE_IMSG_THRD << MV_XOR_V2_DMA_IMSG_THRD_SHIFT);
274 	reg |= MV_XOR_V2_DMA_IMSG_TIMER_EN;
275 	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
276 
277 	/* Configure Timer Threshold */
278 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_TMOT);
279 	reg &= (~MV_XOR_V2_DMA_IMSG_TIMER_THRD_MASK <<
280 		MV_XOR_V2_DMA_IMSG_TIMER_THRD_SHIFT);
281 	reg |= (MV_XOR_V2_TIMER_THRD << MV_XOR_V2_DMA_IMSG_TIMER_THRD_SHIFT);
282 	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_TMOT);
283 }
284 
285 static irqreturn_t mv_xor_v2_interrupt_handler(int irq, void *data)
286 {
287 	struct mv_xor_v2_device *xor_dev = data;
288 	unsigned int ndescs;
289 	u32 reg;
290 
291 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_DONE_OFF);
292 
293 	ndescs = ((reg >> MV_XOR_V2_DMA_DESQ_DONE_PENDING_SHIFT) &
294 		  MV_XOR_V2_DMA_DESQ_DONE_PENDING_MASK);
295 
296 	/* No descriptors to process */
297 	if (!ndescs)
298 		return IRQ_NONE;
299 
300 	/* schedule a tasklet to handle descriptors callbacks */
301 	tasklet_schedule(&xor_dev->irq_tasklet);
302 
303 	return IRQ_HANDLED;
304 }
305 
306 /*
307  * submit a descriptor to the DMA engine
308  */
309 static dma_cookie_t
310 mv_xor_v2_tx_submit(struct dma_async_tx_descriptor *tx)
311 {
312 	void *dest_hw_desc;
313 	dma_cookie_t cookie;
314 	struct mv_xor_v2_sw_desc *sw_desc =
315 		container_of(tx, struct mv_xor_v2_sw_desc, async_tx);
316 	struct mv_xor_v2_device *xor_dev =
317 		container_of(tx->chan, struct mv_xor_v2_device, dmachan);
318 
319 	dev_dbg(xor_dev->dmadev.dev,
320 		"%s sw_desc %p: async_tx %p\n",
321 		__func__, sw_desc, &sw_desc->async_tx);
322 
323 	/* assign coookie */
324 	spin_lock_bh(&xor_dev->lock);
325 	cookie = dma_cookie_assign(tx);
326 
327 	/* copy the HW descriptor from the SW descriptor to the DESQ */
328 	dest_hw_desc = xor_dev->hw_desq_virt + xor_dev->hw_queue_idx;
329 
330 	memcpy(dest_hw_desc, &sw_desc->hw_desc, xor_dev->desc_size);
331 
332 	xor_dev->npendings++;
333 	xor_dev->hw_queue_idx++;
334 	if (xor_dev->hw_queue_idx >= MV_XOR_V2_DESC_NUM)
335 		xor_dev->hw_queue_idx = 0;
336 
337 	spin_unlock_bh(&xor_dev->lock);
338 
339 	return cookie;
340 }
341 
342 /*
343  * Prepare a SW descriptor
344  */
345 static struct mv_xor_v2_sw_desc	*
346 mv_xor_v2_prep_sw_desc(struct mv_xor_v2_device *xor_dev)
347 {
348 	struct mv_xor_v2_sw_desc *sw_desc;
349 	bool found = false;
350 
351 	/* Lock the channel */
352 	spin_lock_bh(&xor_dev->lock);
353 
354 	if (list_empty(&xor_dev->free_sw_desc)) {
355 		spin_unlock_bh(&xor_dev->lock);
356 		/* schedule tasklet to free some descriptors */
357 		tasklet_schedule(&xor_dev->irq_tasklet);
358 		return NULL;
359 	}
360 
361 	list_for_each_entry(sw_desc, &xor_dev->free_sw_desc, free_list) {
362 		if (async_tx_test_ack(&sw_desc->async_tx)) {
363 			found = true;
364 			break;
365 		}
366 	}
367 
368 	if (!found) {
369 		spin_unlock_bh(&xor_dev->lock);
370 		return NULL;
371 	}
372 
373 	list_del(&sw_desc->free_list);
374 
375 	/* Release the channel */
376 	spin_unlock_bh(&xor_dev->lock);
377 
378 	return sw_desc;
379 }
380 
381 /*
382  * Prepare a HW descriptor for a memcpy operation
383  */
384 static struct dma_async_tx_descriptor *
385 mv_xor_v2_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest,
386 			  dma_addr_t src, size_t len, unsigned long flags)
387 {
388 	struct mv_xor_v2_sw_desc *sw_desc;
389 	struct mv_xor_v2_descriptor *hw_descriptor;
390 	struct mv_xor_v2_device	*xor_dev;
391 
392 	xor_dev = container_of(chan, struct mv_xor_v2_device, dmachan);
393 
394 	dev_dbg(xor_dev->dmadev.dev,
395 		"%s len: %zu src %pad dest %pad flags: %ld\n",
396 		__func__, len, &src, &dest, flags);
397 
398 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
399 	if (!sw_desc)
400 		return NULL;
401 
402 	sw_desc->async_tx.flags = flags;
403 
404 	/* set the HW descriptor */
405 	hw_descriptor = &sw_desc->hw_desc;
406 
407 	/* save the SW descriptor ID to restore when operation is done */
408 	hw_descriptor->desc_id = sw_desc->idx;
409 
410 	/* Set the MEMCPY control word */
411 	hw_descriptor->desc_ctrl =
412 		DESC_OP_MODE_MEMCPY << DESC_OP_MODE_SHIFT;
413 
414 	if (flags & DMA_PREP_INTERRUPT)
415 		hw_descriptor->desc_ctrl |= DESC_IOD;
416 
417 	/* Set source address */
418 	hw_descriptor->fill_pattern_src_addr[0] = lower_32_bits(src);
419 	hw_descriptor->fill_pattern_src_addr[1] =
420 		upper_32_bits(src) & 0xFFFF;
421 
422 	/* Set Destination address */
423 	hw_descriptor->fill_pattern_src_addr[2] = lower_32_bits(dest);
424 	hw_descriptor->fill_pattern_src_addr[3] =
425 		upper_32_bits(dest) & 0xFFFF;
426 
427 	/* Set buffers size */
428 	hw_descriptor->buff_size = len;
429 
430 	/* return the async tx descriptor */
431 	return &sw_desc->async_tx;
432 }
433 
434 /*
435  * Prepare a HW descriptor for a XOR operation
436  */
437 static struct dma_async_tx_descriptor *
438 mv_xor_v2_prep_dma_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
439 		       unsigned int src_cnt, size_t len, unsigned long flags)
440 {
441 	struct mv_xor_v2_sw_desc *sw_desc;
442 	struct mv_xor_v2_descriptor *hw_descriptor;
443 	struct mv_xor_v2_device	*xor_dev =
444 		container_of(chan, struct mv_xor_v2_device, dmachan);
445 	int i;
446 
447 	if (src_cnt > MV_XOR_V2_CMD_LINE_NUM_MAX_D_BUF || src_cnt < 1)
448 		return NULL;
449 
450 	dev_dbg(xor_dev->dmadev.dev,
451 		"%s src_cnt: %d len: %zu dest %pad flags: %ld\n",
452 		__func__, src_cnt, len, &dest, flags);
453 
454 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
455 	if (!sw_desc)
456 		return NULL;
457 
458 	sw_desc->async_tx.flags = flags;
459 
460 	/* set the HW descriptor */
461 	hw_descriptor = &sw_desc->hw_desc;
462 
463 	/* save the SW descriptor ID to restore when operation is done */
464 	hw_descriptor->desc_id = sw_desc->idx;
465 
466 	/* Set the XOR control word */
467 	hw_descriptor->desc_ctrl =
468 		DESC_OP_MODE_XOR << DESC_OP_MODE_SHIFT;
469 	hw_descriptor->desc_ctrl |= DESC_P_BUFFER_ENABLE;
470 
471 	if (flags & DMA_PREP_INTERRUPT)
472 		hw_descriptor->desc_ctrl |= DESC_IOD;
473 
474 	/* Set the data buffers */
475 	for (i = 0; i < src_cnt; i++)
476 		mv_xor_v2_set_data_buffers(xor_dev, hw_descriptor, src[i], i);
477 
478 	hw_descriptor->desc_ctrl |=
479 		src_cnt << DESC_NUM_ACTIVE_D_BUF_SHIFT;
480 
481 	/* Set Destination address */
482 	hw_descriptor->fill_pattern_src_addr[2] = lower_32_bits(dest);
483 	hw_descriptor->fill_pattern_src_addr[3] =
484 		upper_32_bits(dest) & 0xFFFF;
485 
486 	/* Set buffers size */
487 	hw_descriptor->buff_size = len;
488 
489 	/* return the async tx descriptor */
490 	return &sw_desc->async_tx;
491 }
492 
493 /*
494  * Prepare a HW descriptor for interrupt operation.
495  */
496 static struct dma_async_tx_descriptor *
497 mv_xor_v2_prep_dma_interrupt(struct dma_chan *chan, unsigned long flags)
498 {
499 	struct mv_xor_v2_sw_desc *sw_desc;
500 	struct mv_xor_v2_descriptor *hw_descriptor;
501 	struct mv_xor_v2_device	*xor_dev =
502 		container_of(chan, struct mv_xor_v2_device, dmachan);
503 
504 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
505 	if (!sw_desc)
506 		return NULL;
507 
508 	/* set the HW descriptor */
509 	hw_descriptor = &sw_desc->hw_desc;
510 
511 	/* save the SW descriptor ID to restore when operation is done */
512 	hw_descriptor->desc_id = sw_desc->idx;
513 
514 	/* Set the INTERRUPT control word */
515 	hw_descriptor->desc_ctrl =
516 		DESC_OP_MODE_NOP << DESC_OP_MODE_SHIFT;
517 	hw_descriptor->desc_ctrl |= DESC_IOD;
518 
519 	/* return the async tx descriptor */
520 	return &sw_desc->async_tx;
521 }
522 
523 /*
524  * push pending transactions to hardware
525  */
526 static void mv_xor_v2_issue_pending(struct dma_chan *chan)
527 {
528 	struct mv_xor_v2_device *xor_dev =
529 		container_of(chan, struct mv_xor_v2_device, dmachan);
530 
531 	spin_lock_bh(&xor_dev->lock);
532 
533 	/*
534 	 * update the engine with the number of descriptors to
535 	 * process
536 	 */
537 	mv_xor_v2_add_desc_to_desq(xor_dev, xor_dev->npendings);
538 	xor_dev->npendings = 0;
539 
540 	spin_unlock_bh(&xor_dev->lock);
541 }
542 
543 static inline
544 int mv_xor_v2_get_pending_params(struct mv_xor_v2_device *xor_dev,
545 				 int *pending_ptr)
546 {
547 	u32 reg;
548 
549 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_DONE_OFF);
550 
551 	/* get the next pending descriptor index */
552 	*pending_ptr = ((reg >> MV_XOR_V2_DMA_DESQ_DONE_READ_PTR_SHIFT) &
553 			MV_XOR_V2_DMA_DESQ_DONE_READ_PTR_MASK);
554 
555 	/* get the number of descriptors pending handle */
556 	return ((reg >> MV_XOR_V2_DMA_DESQ_DONE_PENDING_SHIFT) &
557 		MV_XOR_V2_DMA_DESQ_DONE_PENDING_MASK);
558 }
559 
560 /*
561  * handle the descriptors after HW process
562  */
563 static void mv_xor_v2_tasklet(unsigned long data)
564 {
565 	struct mv_xor_v2_device *xor_dev = (struct mv_xor_v2_device *) data;
566 	int pending_ptr, num_of_pending, i;
567 	struct mv_xor_v2_sw_desc *next_pending_sw_desc = NULL;
568 
569 	dev_dbg(xor_dev->dmadev.dev, "%s %d\n", __func__, __LINE__);
570 
571 	/* get the pending descriptors parameters */
572 	num_of_pending = mv_xor_v2_get_pending_params(xor_dev, &pending_ptr);
573 
574 	/* loop over free descriptors */
575 	for (i = 0; i < num_of_pending; i++) {
576 		struct mv_xor_v2_descriptor *next_pending_hw_desc =
577 			xor_dev->hw_desq_virt + pending_ptr;
578 
579 		/* get the SW descriptor related to the HW descriptor */
580 		next_pending_sw_desc =
581 			&xor_dev->sw_desq[next_pending_hw_desc->desc_id];
582 
583 		/* call the callback */
584 		if (next_pending_sw_desc->async_tx.cookie > 0) {
585 			/*
586 			 * update the channel's completed cookie - no
587 			 * lock is required the IMSG threshold provide
588 			 * the locking
589 			 */
590 			dma_cookie_complete(&next_pending_sw_desc->async_tx);
591 
592 			dma_descriptor_unmap(&next_pending_sw_desc->async_tx);
593 			dmaengine_desc_get_callback_invoke(
594 					&next_pending_sw_desc->async_tx, NULL);
595 		}
596 
597 		dma_run_dependencies(&next_pending_sw_desc->async_tx);
598 
599 		/* Lock the channel */
600 		spin_lock_bh(&xor_dev->lock);
601 
602 		/* add the SW descriptor to the free descriptors list */
603 		list_add(&next_pending_sw_desc->free_list,
604 			 &xor_dev->free_sw_desc);
605 
606 		/* Release the channel */
607 		spin_unlock_bh(&xor_dev->lock);
608 
609 		/* increment the next descriptor */
610 		pending_ptr++;
611 		if (pending_ptr >= MV_XOR_V2_DESC_NUM)
612 			pending_ptr = 0;
613 	}
614 
615 	if (num_of_pending != 0) {
616 		/* free the descriptores */
617 		mv_xor_v2_free_desc_from_desq(xor_dev, num_of_pending);
618 	}
619 }
620 
621 /*
622  *	Set DMA Interrupt-message (IMSG) parameters
623  */
624 static void mv_xor_v2_set_msi_msg(struct msi_desc *desc, struct msi_msg *msg)
625 {
626 	struct mv_xor_v2_device *xor_dev = dev_get_drvdata(desc->dev);
627 
628 	writel(msg->address_lo,
629 	       xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_BALR_OFF);
630 	writel(msg->address_hi & 0xFFFF,
631 	       xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_BAHR_OFF);
632 	writel(msg->data,
633 	       xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_CDAT_OFF);
634 }
635 
636 static int mv_xor_v2_descq_init(struct mv_xor_v2_device *xor_dev)
637 {
638 	u32 reg;
639 
640 	/* write the DESQ size to the DMA engine */
641 	writel(MV_XOR_V2_DESC_NUM,
642 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_SIZE_OFF);
643 
644 	/* write the DESQ address to the DMA enngine*/
645 	writel(lower_32_bits(xor_dev->hw_desq),
646 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_BALR_OFF);
647 	writel(upper_32_bits(xor_dev->hw_desq),
648 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_BAHR_OFF);
649 
650 	/*
651 	 * This is a temporary solution, until we activate the
652 	 * SMMU. Set the attributes for reading & writing data buffers
653 	 * & descriptors to:
654 	 *
655 	 *  - OuterShareable - Snoops will be performed on CPU caches
656 	 *  - Enable cacheable - Bufferable, Modifiable, Other Allocate
657 	 *    and Allocate
658 	 */
659 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_ARATTR_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_ARATTR_OFF);
664 
665 	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_AWATTR_OFF);
666 	reg &= ~MV_XOR_V2_DMA_DESQ_ATTR_CACHE_MASK;
667 	reg |= MV_XOR_V2_DMA_DESQ_ATTR_OUTER_SHAREABLE |
668 		MV_XOR_V2_DMA_DESQ_ATTR_CACHEABLE;
669 	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_AWATTR_OFF);
670 
671 	/* BW CTRL - set values to optimize the XOR performance:
672 	 *
673 	 *  - Set WrBurstLen & RdBurstLen - the unit will issue
674 	 *    maximum of 256B write/read transactions.
675 	 * -  Limit the number of outstanding write & read data
676 	 *    (OBB/IBB) requests to the maximal value.
677 	*/
678 	reg = ((MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_RD_VAL <<
679 		MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_RD_SHIFT) |
680 	       (MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_WR_VAL  <<
681 		MV_XOR_V2_GLOB_BW_CTRL_NUM_OSTD_WR_SHIFT) |
682 	       (MV_XOR_V2_GLOB_BW_CTRL_RD_BURST_LEN_VAL <<
683 		MV_XOR_V2_GLOB_BW_CTRL_RD_BURST_LEN_SHIFT) |
684 	       (MV_XOR_V2_GLOB_BW_CTRL_WR_BURST_LEN_VAL <<
685 		MV_XOR_V2_GLOB_BW_CTRL_WR_BURST_LEN_SHIFT));
686 	writel(reg, xor_dev->glob_base + MV_XOR_V2_GLOB_BW_CTRL);
687 
688 	/* Disable the AXI timer feature */
689 	reg = readl(xor_dev->glob_base + MV_XOR_V2_GLOB_PAUSE);
690 	reg |= MV_XOR_V2_GLOB_PAUSE_AXI_TIME_DIS_VAL;
691 	writel(reg, xor_dev->glob_base + MV_XOR_V2_GLOB_PAUSE);
692 
693 	/* enable the DMA engine */
694 	writel(0, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_STOP_OFF);
695 
696 	return 0;
697 }
698 
699 static int mv_xor_v2_suspend(struct platform_device *dev, pm_message_t state)
700 {
701 	struct mv_xor_v2_device *xor_dev = platform_get_drvdata(dev);
702 
703 	/* Set this bit to disable to stop the XOR unit. */
704 	writel(0x1, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_STOP_OFF);
705 
706 	return 0;
707 }
708 
709 static int mv_xor_v2_resume(struct platform_device *dev)
710 {
711 	struct mv_xor_v2_device *xor_dev = platform_get_drvdata(dev);
712 
713 	mv_xor_v2_set_desc_size(xor_dev);
714 	mv_xor_v2_enable_imsg_thrd(xor_dev);
715 	mv_xor_v2_descq_init(xor_dev);
716 
717 	return 0;
718 }
719 
720 static int mv_xor_v2_probe(struct platform_device *pdev)
721 {
722 	struct mv_xor_v2_device *xor_dev;
723 	struct resource *res;
724 	int i, ret = 0;
725 	struct dma_device *dma_dev;
726 	struct mv_xor_v2_sw_desc *sw_desc;
727 	struct msi_desc *msi_desc;
728 
729 	BUILD_BUG_ON(sizeof(struct mv_xor_v2_descriptor) !=
730 		     MV_XOR_V2_EXT_DESC_SIZE);
731 
732 	xor_dev = devm_kzalloc(&pdev->dev, sizeof(*xor_dev), GFP_KERNEL);
733 	if (!xor_dev)
734 		return -ENOMEM;
735 
736 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
737 	xor_dev->dma_base = devm_ioremap_resource(&pdev->dev, res);
738 	if (IS_ERR(xor_dev->dma_base))
739 		return PTR_ERR(xor_dev->dma_base);
740 
741 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
742 	xor_dev->glob_base = devm_ioremap_resource(&pdev->dev, res);
743 	if (IS_ERR(xor_dev->glob_base))
744 		return PTR_ERR(xor_dev->glob_base);
745 
746 	platform_set_drvdata(pdev, xor_dev);
747 
748 	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40));
749 	if (ret)
750 		return ret;
751 
752 	xor_dev->reg_clk = devm_clk_get(&pdev->dev, "reg");
753 	if (PTR_ERR(xor_dev->reg_clk) != -ENOENT) {
754 		if (!IS_ERR(xor_dev->reg_clk)) {
755 			ret = clk_prepare_enable(xor_dev->reg_clk);
756 			if (ret)
757 				return ret;
758 		} else {
759 			return PTR_ERR(xor_dev->reg_clk);
760 		}
761 	}
762 
763 	xor_dev->clk = devm_clk_get(&pdev->dev, NULL);
764 	if (IS_ERR(xor_dev->clk) && PTR_ERR(xor_dev->clk) == -EPROBE_DEFER) {
765 		ret = EPROBE_DEFER;
766 		goto disable_reg_clk;
767 	}
768 	if (!IS_ERR(xor_dev->clk)) {
769 		ret = clk_prepare_enable(xor_dev->clk);
770 		if (ret)
771 			goto disable_reg_clk;
772 	}
773 
774 	ret = platform_msi_domain_alloc_irqs(&pdev->dev, 1,
775 					     mv_xor_v2_set_msi_msg);
776 	if (ret)
777 		goto disable_clk;
778 
779 	msi_desc = first_msi_entry(&pdev->dev);
780 	if (!msi_desc)
781 		goto free_msi_irqs;
782 	xor_dev->msi_desc = msi_desc;
783 
784 	ret = devm_request_irq(&pdev->dev, msi_desc->irq,
785 			       mv_xor_v2_interrupt_handler, 0,
786 			       dev_name(&pdev->dev), xor_dev);
787 	if (ret)
788 		goto free_msi_irqs;
789 
790 	tasklet_init(&xor_dev->irq_tasklet, mv_xor_v2_tasklet,
791 		     (unsigned long) xor_dev);
792 
793 	xor_dev->desc_size = mv_xor_v2_set_desc_size(xor_dev);
794 
795 	dma_cookie_init(&xor_dev->dmachan);
796 
797 	/*
798 	 * allocate coherent memory for hardware descriptors
799 	 * note: writecombine gives slightly better performance, but
800 	 * requires that we explicitly flush the writes
801 	 */
802 	xor_dev->hw_desq_virt =
803 		dma_alloc_coherent(&pdev->dev,
804 				   xor_dev->desc_size * MV_XOR_V2_DESC_NUM,
805 				   &xor_dev->hw_desq, GFP_KERNEL);
806 	if (!xor_dev->hw_desq_virt) {
807 		ret = -ENOMEM;
808 		goto free_msi_irqs;
809 	}
810 
811 	/* alloc memory for the SW descriptors */
812 	xor_dev->sw_desq = devm_kcalloc(&pdev->dev,
813 					MV_XOR_V2_DESC_NUM, sizeof(*sw_desc),
814 					GFP_KERNEL);
815 	if (!xor_dev->sw_desq) {
816 		ret = -ENOMEM;
817 		goto free_hw_desq;
818 	}
819 
820 	spin_lock_init(&xor_dev->lock);
821 
822 	/* init the free SW descriptors list */
823 	INIT_LIST_HEAD(&xor_dev->free_sw_desc);
824 
825 	/* add all SW descriptors to the free list */
826 	for (i = 0; i < MV_XOR_V2_DESC_NUM; i++) {
827 		struct mv_xor_v2_sw_desc *sw_desc =
828 			xor_dev->sw_desq + i;
829 		sw_desc->idx = i;
830 		dma_async_tx_descriptor_init(&sw_desc->async_tx,
831 					     &xor_dev->dmachan);
832 		sw_desc->async_tx.tx_submit = mv_xor_v2_tx_submit;
833 		async_tx_ack(&sw_desc->async_tx);
834 
835 		list_add(&sw_desc->free_list,
836 			 &xor_dev->free_sw_desc);
837 	}
838 
839 	dma_dev = &xor_dev->dmadev;
840 
841 	/* set DMA capabilities */
842 	dma_cap_zero(dma_dev->cap_mask);
843 	dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
844 	dma_cap_set(DMA_XOR, dma_dev->cap_mask);
845 	dma_cap_set(DMA_INTERRUPT, dma_dev->cap_mask);
846 
847 	/* init dma link list */
848 	INIT_LIST_HEAD(&dma_dev->channels);
849 
850 	/* set base routines */
851 	dma_dev->device_tx_status = dma_cookie_status;
852 	dma_dev->device_issue_pending = mv_xor_v2_issue_pending;
853 	dma_dev->dev = &pdev->dev;
854 
855 	dma_dev->device_prep_dma_memcpy = mv_xor_v2_prep_dma_memcpy;
856 	dma_dev->device_prep_dma_interrupt = mv_xor_v2_prep_dma_interrupt;
857 	dma_dev->max_xor = 8;
858 	dma_dev->device_prep_dma_xor = mv_xor_v2_prep_dma_xor;
859 
860 	xor_dev->dmachan.device = dma_dev;
861 
862 	list_add_tail(&xor_dev->dmachan.device_node,
863 		      &dma_dev->channels);
864 
865 	mv_xor_v2_enable_imsg_thrd(xor_dev);
866 
867 	mv_xor_v2_descq_init(xor_dev);
868 
869 	ret = dma_async_device_register(dma_dev);
870 	if (ret)
871 		goto free_hw_desq;
872 
873 	dev_notice(&pdev->dev, "Marvell Version 2 XOR driver\n");
874 
875 	return 0;
876 
877 free_hw_desq:
878 	dma_free_coherent(&pdev->dev,
879 			  xor_dev->desc_size * MV_XOR_V2_DESC_NUM,
880 			  xor_dev->hw_desq_virt, xor_dev->hw_desq);
881 free_msi_irqs:
882 	platform_msi_domain_free_irqs(&pdev->dev);
883 disable_clk:
884 	clk_disable_unprepare(xor_dev->clk);
885 disable_reg_clk:
886 	clk_disable_unprepare(xor_dev->reg_clk);
887 	return ret;
888 }
889 
890 static int mv_xor_v2_remove(struct platform_device *pdev)
891 {
892 	struct mv_xor_v2_device *xor_dev = platform_get_drvdata(pdev);
893 
894 	dma_async_device_unregister(&xor_dev->dmadev);
895 
896 	dma_free_coherent(&pdev->dev,
897 			  xor_dev->desc_size * MV_XOR_V2_DESC_NUM,
898 			  xor_dev->hw_desq_virt, xor_dev->hw_desq);
899 
900 	devm_free_irq(&pdev->dev, xor_dev->msi_desc->irq, xor_dev);
901 
902 	platform_msi_domain_free_irqs(&pdev->dev);
903 
904 	tasklet_kill(&xor_dev->irq_tasklet);
905 
906 	clk_disable_unprepare(xor_dev->clk);
907 
908 	return 0;
909 }
910 
911 #ifdef CONFIG_OF
912 static const struct of_device_id mv_xor_v2_dt_ids[] = {
913 	{ .compatible = "marvell,xor-v2", },
914 	{},
915 };
916 MODULE_DEVICE_TABLE(of, mv_xor_v2_dt_ids);
917 #endif
918 
919 static struct platform_driver mv_xor_v2_driver = {
920 	.probe		= mv_xor_v2_probe,
921 	.suspend	= mv_xor_v2_suspend,
922 	.resume		= mv_xor_v2_resume,
923 	.remove		= mv_xor_v2_remove,
924 	.driver		= {
925 		.name	= "mv_xor_v2",
926 		.of_match_table = of_match_ptr(mv_xor_v2_dt_ids),
927 	},
928 };
929 
930 module_platform_driver(mv_xor_v2_driver);
931 
932 MODULE_DESCRIPTION("DMA engine driver for Marvell's Version 2 of XOR engine");
933 MODULE_LICENSE("GPL");
934