xref: /openbmc/linux/drivers/dma/xgene-dma.c (revision 43bcad2b)
1 /*
2  * Applied Micro X-Gene SoC DMA engine Driver
3  *
4  * Copyright (c) 2015, Applied Micro Circuits Corporation
5  * Authors: Rameshwar Prasad Sahu <rsahu@apm.com>
6  *	    Loc Ho <lho@apm.com>
7  *
8  * This program is free software; you can redistribute  it and/or modify it
9  * under  the terms of  the GNU General  Public License as published by the
10  * Free Software Foundation;  either version 2 of the  License, or (at your
11  * option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
20  *
21  * NOTE: PM support is currently not available.
22  */
23 
24 #include <linux/acpi.h>
25 #include <linux/clk.h>
26 #include <linux/delay.h>
27 #include <linux/dma-mapping.h>
28 #include <linux/dmaengine.h>
29 #include <linux/dmapool.h>
30 #include <linux/interrupt.h>
31 #include <linux/io.h>
32 #include <linux/module.h>
33 #include <linux/of_device.h>
34 
35 #include "dmaengine.h"
36 
37 /* X-Gene DMA ring csr registers and bit definations */
38 #define XGENE_DMA_RING_CONFIG			0x04
39 #define XGENE_DMA_RING_ENABLE			BIT(31)
40 #define XGENE_DMA_RING_ID			0x08
41 #define XGENE_DMA_RING_ID_SETUP(v)		((v) | BIT(31))
42 #define XGENE_DMA_RING_ID_BUF			0x0C
43 #define XGENE_DMA_RING_ID_BUF_SETUP(v)		(((v) << 9) | BIT(21))
44 #define XGENE_DMA_RING_THRESLD0_SET1		0x30
45 #define XGENE_DMA_RING_THRESLD0_SET1_VAL	0X64
46 #define XGENE_DMA_RING_THRESLD1_SET1		0x34
47 #define XGENE_DMA_RING_THRESLD1_SET1_VAL	0xC8
48 #define XGENE_DMA_RING_HYSTERESIS		0x68
49 #define XGENE_DMA_RING_HYSTERESIS_VAL		0xFFFFFFFF
50 #define XGENE_DMA_RING_STATE			0x6C
51 #define XGENE_DMA_RING_STATE_WR_BASE		0x70
52 #define XGENE_DMA_RING_NE_INT_MODE		0x017C
53 #define XGENE_DMA_RING_NE_INT_MODE_SET(m, v)	\
54 	((m) = ((m) & ~BIT(31 - (v))) | BIT(31 - (v)))
55 #define XGENE_DMA_RING_NE_INT_MODE_RESET(m, v)	\
56 	((m) &= (~BIT(31 - (v))))
57 #define XGENE_DMA_RING_CLKEN			0xC208
58 #define XGENE_DMA_RING_SRST			0xC200
59 #define XGENE_DMA_RING_MEM_RAM_SHUTDOWN		0xD070
60 #define XGENE_DMA_RING_BLK_MEM_RDY		0xD074
61 #define XGENE_DMA_RING_BLK_MEM_RDY_VAL		0xFFFFFFFF
62 #define XGENE_DMA_RING_DESC_CNT(v)		(((v) & 0x0001FFFE) >> 1)
63 #define XGENE_DMA_RING_ID_GET(owner, num)	(((owner) << 6) | (num))
64 #define XGENE_DMA_RING_DST_ID(v)		((1 << 10) | (v))
65 #define XGENE_DMA_RING_CMD_OFFSET		0x2C
66 #define XGENE_DMA_RING_CMD_BASE_OFFSET(v)	((v) << 6)
67 #define XGENE_DMA_RING_COHERENT_SET(m)		\
68 	(((u32 *)(m))[2] |= BIT(4))
69 #define XGENE_DMA_RING_ADDRL_SET(m, v)		\
70 	(((u32 *)(m))[2] |= (((v) >> 8) << 5))
71 #define XGENE_DMA_RING_ADDRH_SET(m, v)		\
72 	(((u32 *)(m))[3] |= ((v) >> 35))
73 #define XGENE_DMA_RING_ACCEPTLERR_SET(m)	\
74 	(((u32 *)(m))[3] |= BIT(19))
75 #define XGENE_DMA_RING_SIZE_SET(m, v)		\
76 	(((u32 *)(m))[3] |= ((v) << 23))
77 #define XGENE_DMA_RING_RECOMBBUF_SET(m)		\
78 	(((u32 *)(m))[3] |= BIT(27))
79 #define XGENE_DMA_RING_RECOMTIMEOUTL_SET(m)	\
80 	(((u32 *)(m))[3] |= (0x7 << 28))
81 #define XGENE_DMA_RING_RECOMTIMEOUTH_SET(m)	\
82 	(((u32 *)(m))[4] |= 0x3)
83 #define XGENE_DMA_RING_SELTHRSH_SET(m)		\
84 	(((u32 *)(m))[4] |= BIT(3))
85 #define XGENE_DMA_RING_TYPE_SET(m, v)		\
86 	(((u32 *)(m))[4] |= ((v) << 19))
87 
88 /* X-Gene DMA device csr registers and bit definitions */
89 #define XGENE_DMA_IPBRR				0x0
90 #define XGENE_DMA_DEV_ID_RD(v)			((v) & 0x00000FFF)
91 #define XGENE_DMA_BUS_ID_RD(v)			(((v) >> 12) & 3)
92 #define XGENE_DMA_REV_NO_RD(v)			(((v) >> 14) & 3)
93 #define XGENE_DMA_GCR				0x10
94 #define XGENE_DMA_CH_SETUP(v)			\
95 	((v) = ((v) & ~0x000FFFFF) | 0x000AAFFF)
96 #define XGENE_DMA_ENABLE(v)			((v) |= BIT(31))
97 #define XGENE_DMA_DISABLE(v)			((v) &= ~BIT(31))
98 #define XGENE_DMA_RAID6_CONT			0x14
99 #define XGENE_DMA_RAID6_MULTI_CTRL(v)		((v) << 24)
100 #define XGENE_DMA_INT				0x70
101 #define XGENE_DMA_INT_MASK			0x74
102 #define XGENE_DMA_INT_ALL_MASK			0xFFFFFFFF
103 #define XGENE_DMA_INT_ALL_UNMASK		0x0
104 #define XGENE_DMA_INT_MASK_SHIFT		0x14
105 #define XGENE_DMA_RING_INT0_MASK		0x90A0
106 #define XGENE_DMA_RING_INT1_MASK		0x90A8
107 #define XGENE_DMA_RING_INT2_MASK		0x90B0
108 #define XGENE_DMA_RING_INT3_MASK		0x90B8
109 #define XGENE_DMA_RING_INT4_MASK		0x90C0
110 #define XGENE_DMA_CFG_RING_WQ_ASSOC		0x90E0
111 #define XGENE_DMA_ASSOC_RING_MNGR1		0xFFFFFFFF
112 #define XGENE_DMA_MEM_RAM_SHUTDOWN		0xD070
113 #define XGENE_DMA_BLK_MEM_RDY			0xD074
114 #define XGENE_DMA_BLK_MEM_RDY_VAL		0xFFFFFFFF
115 
116 /* X-Gene SoC EFUSE csr register and bit defination */
117 #define XGENE_SOC_JTAG1_SHADOW			0x18
118 #define XGENE_DMA_PQ_DISABLE_MASK		BIT(13)
119 
120 /* X-Gene DMA Descriptor format */
121 #define XGENE_DMA_DESC_NV_BIT			BIT_ULL(50)
122 #define XGENE_DMA_DESC_IN_BIT			BIT_ULL(55)
123 #define XGENE_DMA_DESC_C_BIT			BIT_ULL(63)
124 #define XGENE_DMA_DESC_DR_BIT			BIT_ULL(61)
125 #define XGENE_DMA_DESC_ELERR_POS		46
126 #define XGENE_DMA_DESC_RTYPE_POS		56
127 #define XGENE_DMA_DESC_LERR_POS			60
128 #define XGENE_DMA_DESC_BUFLEN_POS		48
129 #define XGENE_DMA_DESC_HOENQ_NUM_POS		48
130 #define XGENE_DMA_DESC_ELERR_RD(m)		\
131 	(((m) >> XGENE_DMA_DESC_ELERR_POS) & 0x3)
132 #define XGENE_DMA_DESC_LERR_RD(m)		\
133 	(((m) >> XGENE_DMA_DESC_LERR_POS) & 0x7)
134 #define XGENE_DMA_DESC_STATUS(elerr, lerr)	\
135 	(((elerr) << 4) | (lerr))
136 
137 /* X-Gene DMA descriptor empty s/w signature */
138 #define XGENE_DMA_DESC_EMPTY_SIGNATURE		~0ULL
139 
140 /* X-Gene DMA configurable parameters defines */
141 #define XGENE_DMA_RING_NUM		512
142 #define XGENE_DMA_BUFNUM		0x0
143 #define XGENE_DMA_CPU_BUFNUM		0x18
144 #define XGENE_DMA_RING_OWNER_DMA	0x03
145 #define XGENE_DMA_RING_OWNER_CPU	0x0F
146 #define XGENE_DMA_RING_TYPE_REGULAR	0x01
147 #define XGENE_DMA_RING_WQ_DESC_SIZE	32	/* 32 Bytes */
148 #define XGENE_DMA_RING_NUM_CONFIG	5
149 #define XGENE_DMA_MAX_CHANNEL		4
150 #define XGENE_DMA_XOR_CHANNEL		0
151 #define XGENE_DMA_PQ_CHANNEL		1
152 #define XGENE_DMA_MAX_BYTE_CNT		0x4000	/* 16 KB */
153 #define XGENE_DMA_MAX_64B_DESC_BYTE_CNT	0x14000	/* 80 KB */
154 #define XGENE_DMA_MAX_XOR_SRC		5
155 #define XGENE_DMA_16K_BUFFER_LEN_CODE	0x0
156 #define XGENE_DMA_INVALID_LEN_CODE	0x7800000000000000ULL
157 
158 /* X-Gene DMA descriptor error codes */
159 #define ERR_DESC_AXI			0x01
160 #define ERR_BAD_DESC			0x02
161 #define ERR_READ_DATA_AXI		0x03
162 #define ERR_WRITE_DATA_AXI		0x04
163 #define ERR_FBP_TIMEOUT			0x05
164 #define ERR_ECC				0x06
165 #define ERR_DIFF_SIZE			0x08
166 #define ERR_SCT_GAT_LEN			0x09
167 #define ERR_CRC_ERR			0x11
168 #define ERR_CHKSUM			0x12
169 #define ERR_DIF				0x13
170 
171 /* X-Gene DMA error interrupt codes */
172 #define ERR_DIF_SIZE_INT		0x0
173 #define ERR_GS_ERR_INT			0x1
174 #define ERR_FPB_TIMEO_INT		0x2
175 #define ERR_WFIFO_OVF_INT		0x3
176 #define ERR_RFIFO_OVF_INT		0x4
177 #define ERR_WR_TIMEO_INT		0x5
178 #define ERR_RD_TIMEO_INT		0x6
179 #define ERR_WR_ERR_INT			0x7
180 #define ERR_RD_ERR_INT			0x8
181 #define ERR_BAD_DESC_INT		0x9
182 #define ERR_DESC_DST_INT		0xA
183 #define ERR_DESC_SRC_INT		0xB
184 
185 /* X-Gene DMA flyby operation code */
186 #define FLYBY_2SRC_XOR			0x80
187 #define FLYBY_3SRC_XOR			0x90
188 #define FLYBY_4SRC_XOR			0xA0
189 #define FLYBY_5SRC_XOR			0xB0
190 
191 /* X-Gene DMA SW descriptor flags */
192 #define XGENE_DMA_FLAG_64B_DESC		BIT(0)
193 
194 /* Define to dump X-Gene DMA descriptor */
195 #define XGENE_DMA_DESC_DUMP(desc, m)	\
196 	print_hex_dump(KERN_ERR, (m),	\
197 			DUMP_PREFIX_ADDRESS, 16, 8, (desc), 32, 0)
198 
199 #define to_dma_desc_sw(tx)		\
200 	container_of(tx, struct xgene_dma_desc_sw, tx)
201 #define to_dma_chan(dchan)		\
202 	container_of(dchan, struct xgene_dma_chan, dma_chan)
203 
204 #define chan_dbg(chan, fmt, arg...)	\
205 	dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
206 #define chan_err(chan, fmt, arg...)	\
207 	dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
208 
209 struct xgene_dma_desc_hw {
210 	__le64 m0;
211 	__le64 m1;
212 	__le64 m2;
213 	__le64 m3;
214 };
215 
216 enum xgene_dma_ring_cfgsize {
217 	XGENE_DMA_RING_CFG_SIZE_512B,
218 	XGENE_DMA_RING_CFG_SIZE_2KB,
219 	XGENE_DMA_RING_CFG_SIZE_16KB,
220 	XGENE_DMA_RING_CFG_SIZE_64KB,
221 	XGENE_DMA_RING_CFG_SIZE_512KB,
222 	XGENE_DMA_RING_CFG_SIZE_INVALID
223 };
224 
225 struct xgene_dma_ring {
226 	struct xgene_dma *pdma;
227 	u8 buf_num;
228 	u16 id;
229 	u16 num;
230 	u16 head;
231 	u16 owner;
232 	u16 slots;
233 	u16 dst_ring_num;
234 	u32 size;
235 	void __iomem *cmd;
236 	void __iomem *cmd_base;
237 	dma_addr_t desc_paddr;
238 	u32 state[XGENE_DMA_RING_NUM_CONFIG];
239 	enum xgene_dma_ring_cfgsize cfgsize;
240 	union {
241 		void *desc_vaddr;
242 		struct xgene_dma_desc_hw *desc_hw;
243 	};
244 };
245 
246 struct xgene_dma_desc_sw {
247 	struct xgene_dma_desc_hw desc1;
248 	struct xgene_dma_desc_hw desc2;
249 	u32 flags;
250 	struct list_head node;
251 	struct list_head tx_list;
252 	struct dma_async_tx_descriptor tx;
253 };
254 
255 /**
256  * struct xgene_dma_chan - internal representation of an X-Gene DMA channel
257  * @dma_chan: dmaengine channel object member
258  * @pdma: X-Gene DMA device structure reference
259  * @dev: struct device reference for dma mapping api
260  * @id: raw id of this channel
261  * @rx_irq: channel IRQ
262  * @name: name of X-Gene DMA channel
263  * @lock: serializes enqueue/dequeue operations to the descriptor pool
264  * @pending: number of transaction request pushed to DMA controller for
265  *	execution, but still waiting for completion,
266  * @max_outstanding: max number of outstanding request we can push to channel
267  * @ld_pending: descriptors which are queued to run, but have not yet been
268  *	submitted to the hardware for execution
269  * @ld_running: descriptors which are currently being executing by the hardware
270  * @ld_completed: descriptors which have finished execution by the hardware.
271  *	These descriptors have already had their cleanup actions run. They
272  *	are waiting for the ACK bit to be set by the async tx API.
273  * @desc_pool: descriptor pool for DMA operations
274  * @tasklet: bottom half where all completed descriptors cleans
275  * @tx_ring: transmit ring descriptor that we use to prepare actual
276  *	descriptors for further executions
277  * @rx_ring: receive ring descriptor that we use to get completed DMA
278  *	descriptors during cleanup time
279  */
280 struct xgene_dma_chan {
281 	struct dma_chan dma_chan;
282 	struct xgene_dma *pdma;
283 	struct device *dev;
284 	int id;
285 	int rx_irq;
286 	char name[10];
287 	spinlock_t lock;
288 	int pending;
289 	int max_outstanding;
290 	struct list_head ld_pending;
291 	struct list_head ld_running;
292 	struct list_head ld_completed;
293 	struct dma_pool *desc_pool;
294 	struct tasklet_struct tasklet;
295 	struct xgene_dma_ring tx_ring;
296 	struct xgene_dma_ring rx_ring;
297 };
298 
299 /**
300  * struct xgene_dma - internal representation of an X-Gene DMA device
301  * @err_irq: DMA error irq number
302  * @ring_num: start id number for DMA ring
303  * @csr_dma: base for DMA register access
304  * @csr_ring: base for DMA ring register access
305  * @csr_ring_cmd: base for DMA ring command register access
306  * @csr_efuse: base for efuse register access
307  * @dma_dev: embedded struct dma_device
308  * @chan: reference to X-Gene DMA channels
309  */
310 struct xgene_dma {
311 	struct device *dev;
312 	struct clk *clk;
313 	int err_irq;
314 	int ring_num;
315 	void __iomem *csr_dma;
316 	void __iomem *csr_ring;
317 	void __iomem *csr_ring_cmd;
318 	void __iomem *csr_efuse;
319 	struct dma_device dma_dev[XGENE_DMA_MAX_CHANNEL];
320 	struct xgene_dma_chan chan[XGENE_DMA_MAX_CHANNEL];
321 };
322 
323 static const char * const xgene_dma_desc_err[] = {
324 	[ERR_DESC_AXI] = "AXI error when reading src/dst link list",
325 	[ERR_BAD_DESC] = "ERR or El_ERR fields not set to zero in desc",
326 	[ERR_READ_DATA_AXI] = "AXI error when reading data",
327 	[ERR_WRITE_DATA_AXI] = "AXI error when writing data",
328 	[ERR_FBP_TIMEOUT] = "Timeout on bufpool fetch",
329 	[ERR_ECC] = "ECC double bit error",
330 	[ERR_DIFF_SIZE] = "Bufpool too small to hold all the DIF result",
331 	[ERR_SCT_GAT_LEN] = "Gather and scatter data length not same",
332 	[ERR_CRC_ERR] = "CRC error",
333 	[ERR_CHKSUM] = "Checksum error",
334 	[ERR_DIF] = "DIF error",
335 };
336 
337 static const char * const xgene_dma_err[] = {
338 	[ERR_DIF_SIZE_INT] = "DIF size error",
339 	[ERR_GS_ERR_INT] = "Gather scatter not same size error",
340 	[ERR_FPB_TIMEO_INT] = "Free pool time out error",
341 	[ERR_WFIFO_OVF_INT] = "Write FIFO over flow error",
342 	[ERR_RFIFO_OVF_INT] = "Read FIFO over flow error",
343 	[ERR_WR_TIMEO_INT] = "Write time out error",
344 	[ERR_RD_TIMEO_INT] = "Read time out error",
345 	[ERR_WR_ERR_INT] = "HBF bus write error",
346 	[ERR_RD_ERR_INT] = "HBF bus read error",
347 	[ERR_BAD_DESC_INT] = "Ring descriptor HE0 not set error",
348 	[ERR_DESC_DST_INT] = "HFB reading dst link address error",
349 	[ERR_DESC_SRC_INT] = "HFB reading src link address error",
350 };
351 
352 static bool is_pq_enabled(struct xgene_dma *pdma)
353 {
354 	u32 val;
355 
356 	val = ioread32(pdma->csr_efuse + XGENE_SOC_JTAG1_SHADOW);
357 	return !(val & XGENE_DMA_PQ_DISABLE_MASK);
358 }
359 
360 static u64 xgene_dma_encode_len(size_t len)
361 {
362 	return (len < XGENE_DMA_MAX_BYTE_CNT) ?
363 		((u64)len << XGENE_DMA_DESC_BUFLEN_POS) :
364 		XGENE_DMA_16K_BUFFER_LEN_CODE;
365 }
366 
367 static u8 xgene_dma_encode_xor_flyby(u32 src_cnt)
368 {
369 	static u8 flyby_type[] = {
370 		FLYBY_2SRC_XOR, /* Dummy */
371 		FLYBY_2SRC_XOR, /* Dummy */
372 		FLYBY_2SRC_XOR,
373 		FLYBY_3SRC_XOR,
374 		FLYBY_4SRC_XOR,
375 		FLYBY_5SRC_XOR
376 	};
377 
378 	return flyby_type[src_cnt];
379 }
380 
381 static u32 xgene_dma_ring_desc_cnt(struct xgene_dma_ring *ring)
382 {
383 	u32 __iomem *cmd_base = ring->cmd_base;
384 	u32 ring_state = ioread32(&cmd_base[1]);
385 
386 	return XGENE_DMA_RING_DESC_CNT(ring_state);
387 }
388 
389 static void xgene_dma_set_src_buffer(__le64 *ext8, size_t *len,
390 				     dma_addr_t *paddr)
391 {
392 	size_t nbytes = (*len < XGENE_DMA_MAX_BYTE_CNT) ?
393 			*len : XGENE_DMA_MAX_BYTE_CNT;
394 
395 	*ext8 |= cpu_to_le64(*paddr);
396 	*ext8 |= cpu_to_le64(xgene_dma_encode_len(nbytes));
397 	*len -= nbytes;
398 	*paddr += nbytes;
399 }
400 
401 static void xgene_dma_invalidate_buffer(__le64 *ext8)
402 {
403 	*ext8 |= cpu_to_le64(XGENE_DMA_INVALID_LEN_CODE);
404 }
405 
406 static __le64 *xgene_dma_lookup_ext8(struct xgene_dma_desc_hw *desc, int idx)
407 {
408 	switch (idx) {
409 	case 0:
410 		return &desc->m1;
411 	case 1:
412 		return &desc->m0;
413 	case 2:
414 		return &desc->m3;
415 	case 3:
416 		return &desc->m2;
417 	default:
418 		pr_err("Invalid dma descriptor index\n");
419 	}
420 
421 	return NULL;
422 }
423 
424 static void xgene_dma_init_desc(struct xgene_dma_desc_hw *desc,
425 				u16 dst_ring_num)
426 {
427 	desc->m0 |= cpu_to_le64(XGENE_DMA_DESC_IN_BIT);
428 	desc->m0 |= cpu_to_le64((u64)XGENE_DMA_RING_OWNER_DMA <<
429 				XGENE_DMA_DESC_RTYPE_POS);
430 	desc->m1 |= cpu_to_le64(XGENE_DMA_DESC_C_BIT);
431 	desc->m3 |= cpu_to_le64((u64)dst_ring_num <<
432 				XGENE_DMA_DESC_HOENQ_NUM_POS);
433 }
434 
435 static void xgene_dma_prep_cpy_desc(struct xgene_dma_chan *chan,
436 				    struct xgene_dma_desc_sw *desc_sw,
437 				    dma_addr_t dst, dma_addr_t src,
438 				    size_t len)
439 {
440 	struct xgene_dma_desc_hw *desc1, *desc2;
441 	int i;
442 
443 	/* Get 1st descriptor */
444 	desc1 = &desc_sw->desc1;
445 	xgene_dma_init_desc(desc1, chan->tx_ring.dst_ring_num);
446 
447 	/* Set destination address */
448 	desc1->m2 |= cpu_to_le64(XGENE_DMA_DESC_DR_BIT);
449 	desc1->m3 |= cpu_to_le64(dst);
450 
451 	/* Set 1st source address */
452 	xgene_dma_set_src_buffer(&desc1->m1, &len, &src);
453 
454 	if (!len)
455 		return;
456 
457 	/*
458 	 * We need to split this source buffer,
459 	 * and need to use 2nd descriptor
460 	 */
461 	desc2 = &desc_sw->desc2;
462 	desc1->m0 |= cpu_to_le64(XGENE_DMA_DESC_NV_BIT);
463 
464 	/* Set 2nd to 5th source address */
465 	for (i = 0; i < 4 && len; i++)
466 		xgene_dma_set_src_buffer(xgene_dma_lookup_ext8(desc2, i),
467 					 &len, &src);
468 
469 	/* Invalidate unused source address field */
470 	for (; i < 4; i++)
471 		xgene_dma_invalidate_buffer(xgene_dma_lookup_ext8(desc2, i));
472 
473 	/* Updated flag that we have prepared 64B descriptor */
474 	desc_sw->flags |= XGENE_DMA_FLAG_64B_DESC;
475 }
476 
477 static void xgene_dma_prep_xor_desc(struct xgene_dma_chan *chan,
478 				    struct xgene_dma_desc_sw *desc_sw,
479 				    dma_addr_t *dst, dma_addr_t *src,
480 				    u32 src_cnt, size_t *nbytes,
481 				    const u8 *scf)
482 {
483 	struct xgene_dma_desc_hw *desc1, *desc2;
484 	size_t len = *nbytes;
485 	int i;
486 
487 	desc1 = &desc_sw->desc1;
488 	desc2 = &desc_sw->desc2;
489 
490 	/* Initialize DMA descriptor */
491 	xgene_dma_init_desc(desc1, chan->tx_ring.dst_ring_num);
492 
493 	/* Set destination address */
494 	desc1->m2 |= cpu_to_le64(XGENE_DMA_DESC_DR_BIT);
495 	desc1->m3 |= cpu_to_le64(*dst);
496 
497 	/* We have multiple source addresses, so need to set NV bit*/
498 	desc1->m0 |= cpu_to_le64(XGENE_DMA_DESC_NV_BIT);
499 
500 	/* Set flyby opcode */
501 	desc1->m2 |= cpu_to_le64(xgene_dma_encode_xor_flyby(src_cnt));
502 
503 	/* Set 1st to 5th source addresses */
504 	for (i = 0; i < src_cnt; i++) {
505 		len = *nbytes;
506 		xgene_dma_set_src_buffer((i == 0) ? &desc1->m1 :
507 					 xgene_dma_lookup_ext8(desc2, i - 1),
508 					 &len, &src[i]);
509 		desc1->m2 |= cpu_to_le64((scf[i] << ((i + 1) * 8)));
510 	}
511 
512 	/* Update meta data */
513 	*nbytes = len;
514 	*dst += XGENE_DMA_MAX_BYTE_CNT;
515 
516 	/* We need always 64B descriptor to perform xor or pq operations */
517 	desc_sw->flags |= XGENE_DMA_FLAG_64B_DESC;
518 }
519 
520 static dma_cookie_t xgene_dma_tx_submit(struct dma_async_tx_descriptor *tx)
521 {
522 	struct xgene_dma_desc_sw *desc;
523 	struct xgene_dma_chan *chan;
524 	dma_cookie_t cookie;
525 
526 	if (unlikely(!tx))
527 		return -EINVAL;
528 
529 	chan = to_dma_chan(tx->chan);
530 	desc = to_dma_desc_sw(tx);
531 
532 	spin_lock_bh(&chan->lock);
533 
534 	cookie = dma_cookie_assign(tx);
535 
536 	/* Add this transaction list onto the tail of the pending queue */
537 	list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
538 
539 	spin_unlock_bh(&chan->lock);
540 
541 	return cookie;
542 }
543 
544 static void xgene_dma_clean_descriptor(struct xgene_dma_chan *chan,
545 				       struct xgene_dma_desc_sw *desc)
546 {
547 	list_del(&desc->node);
548 	chan_dbg(chan, "LD %p free\n", desc);
549 	dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
550 }
551 
552 static struct xgene_dma_desc_sw *xgene_dma_alloc_descriptor(
553 				 struct xgene_dma_chan *chan)
554 {
555 	struct xgene_dma_desc_sw *desc;
556 	dma_addr_t phys;
557 
558 	desc = dma_pool_alloc(chan->desc_pool, GFP_NOWAIT, &phys);
559 	if (!desc) {
560 		chan_err(chan, "Failed to allocate LDs\n");
561 		return NULL;
562 	}
563 
564 	memset(desc, 0, sizeof(*desc));
565 
566 	INIT_LIST_HEAD(&desc->tx_list);
567 	desc->tx.phys = phys;
568 	desc->tx.tx_submit = xgene_dma_tx_submit;
569 	dma_async_tx_descriptor_init(&desc->tx, &chan->dma_chan);
570 
571 	chan_dbg(chan, "LD %p allocated\n", desc);
572 
573 	return desc;
574 }
575 
576 /**
577  * xgene_dma_clean_completed_descriptor - free all descriptors which
578  * has been completed and acked
579  * @chan: X-Gene DMA channel
580  *
581  * This function is used on all completed and acked descriptors.
582  */
583 static void xgene_dma_clean_completed_descriptor(struct xgene_dma_chan *chan)
584 {
585 	struct xgene_dma_desc_sw *desc, *_desc;
586 
587 	/* Run the callback for each descriptor, in order */
588 	list_for_each_entry_safe(desc, _desc, &chan->ld_completed, node) {
589 		if (async_tx_test_ack(&desc->tx))
590 			xgene_dma_clean_descriptor(chan, desc);
591 	}
592 }
593 
594 /**
595  * xgene_dma_run_tx_complete_actions - cleanup a single link descriptor
596  * @chan: X-Gene DMA channel
597  * @desc: descriptor to cleanup and free
598  *
599  * This function is used on a descriptor which has been executed by the DMA
600  * controller. It will run any callbacks, submit any dependencies.
601  */
602 static void xgene_dma_run_tx_complete_actions(struct xgene_dma_chan *chan,
603 					      struct xgene_dma_desc_sw *desc)
604 {
605 	struct dma_async_tx_descriptor *tx = &desc->tx;
606 
607 	/*
608 	 * If this is not the last transaction in the group,
609 	 * then no need to complete cookie and run any callback as
610 	 * this is not the tx_descriptor which had been sent to caller
611 	 * of this DMA request
612 	 */
613 
614 	if (tx->cookie == 0)
615 		return;
616 
617 	dma_cookie_complete(tx);
618 
619 	/* Run the link descriptor callback function */
620 	if (tx->callback)
621 		tx->callback(tx->callback_param);
622 
623 	dma_descriptor_unmap(tx);
624 
625 	/* Run any dependencies */
626 	dma_run_dependencies(tx);
627 }
628 
629 /**
630  * xgene_dma_clean_running_descriptor - move the completed descriptor from
631  * ld_running to ld_completed
632  * @chan: X-Gene DMA channel
633  * @desc: the descriptor which is completed
634  *
635  * Free the descriptor directly if acked by async_tx api,
636  * else move it to queue ld_completed.
637  */
638 static void xgene_dma_clean_running_descriptor(struct xgene_dma_chan *chan,
639 					       struct xgene_dma_desc_sw *desc)
640 {
641 	/* Remove from the list of running transactions */
642 	list_del(&desc->node);
643 
644 	/*
645 	 * the client is allowed to attach dependent operations
646 	 * until 'ack' is set
647 	 */
648 	if (!async_tx_test_ack(&desc->tx)) {
649 		/*
650 		 * Move this descriptor to the list of descriptors which is
651 		 * completed, but still awaiting the 'ack' bit to be set.
652 		 */
653 		list_add_tail(&desc->node, &chan->ld_completed);
654 		return;
655 	}
656 
657 	chan_dbg(chan, "LD %p free\n", desc);
658 	dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
659 }
660 
661 static int xgene_chan_xfer_request(struct xgene_dma_ring *ring,
662 				   struct xgene_dma_desc_sw *desc_sw)
663 {
664 	struct xgene_dma_desc_hw *desc_hw;
665 
666 	/* Check if can push more descriptor to hw for execution */
667 	if (xgene_dma_ring_desc_cnt(ring) > (ring->slots - 2))
668 		return -EBUSY;
669 
670 	/* Get hw descriptor from DMA tx ring */
671 	desc_hw = &ring->desc_hw[ring->head];
672 
673 	/*
674 	 * Increment the head count to point next
675 	 * descriptor for next time
676 	 */
677 	if (++ring->head == ring->slots)
678 		ring->head = 0;
679 
680 	/* Copy prepared sw descriptor data to hw descriptor */
681 	memcpy(desc_hw, &desc_sw->desc1, sizeof(*desc_hw));
682 
683 	/*
684 	 * Check if we have prepared 64B descriptor,
685 	 * in this case we need one more hw descriptor
686 	 */
687 	if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) {
688 		desc_hw = &ring->desc_hw[ring->head];
689 
690 		if (++ring->head == ring->slots)
691 			ring->head = 0;
692 
693 		memcpy(desc_hw, &desc_sw->desc2, sizeof(*desc_hw));
694 	}
695 
696 	/* Notify the hw that we have descriptor ready for execution */
697 	iowrite32((desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) ?
698 		  2 : 1, ring->cmd);
699 
700 	return 0;
701 }
702 
703 /**
704  * xgene_chan_xfer_ld_pending - push any pending transactions to hw
705  * @chan : X-Gene DMA channel
706  *
707  * LOCKING: must hold chan->lock
708  */
709 static void xgene_chan_xfer_ld_pending(struct xgene_dma_chan *chan)
710 {
711 	struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
712 	int ret;
713 
714 	/*
715 	 * If the list of pending descriptors is empty, then we
716 	 * don't need to do any work at all
717 	 */
718 	if (list_empty(&chan->ld_pending)) {
719 		chan_dbg(chan, "No pending LDs\n");
720 		return;
721 	}
722 
723 	/*
724 	 * Move elements from the queue of pending transactions onto the list
725 	 * of running transactions and push it to hw for further executions
726 	 */
727 	list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_pending, node) {
728 		/*
729 		 * Check if have pushed max number of transactions to hw
730 		 * as capable, so let's stop here and will push remaining
731 		 * elements from pening ld queue after completing some
732 		 * descriptors that we have already pushed
733 		 */
734 		if (chan->pending >= chan->max_outstanding)
735 			return;
736 
737 		ret = xgene_chan_xfer_request(&chan->tx_ring, desc_sw);
738 		if (ret)
739 			return;
740 
741 		/*
742 		 * Delete this element from ld pending queue and append it to
743 		 * ld running queue
744 		 */
745 		list_move_tail(&desc_sw->node, &chan->ld_running);
746 
747 		/* Increment the pending transaction count */
748 		chan->pending++;
749 	}
750 }
751 
752 /**
753  * xgene_dma_cleanup_descriptors - cleanup link descriptors which are completed
754  * and move them to ld_completed to free until flag 'ack' is set
755  * @chan: X-Gene DMA channel
756  *
757  * This function is used on descriptors which have been executed by the DMA
758  * controller. It will run any callbacks, submit any dependencies, then
759  * free these descriptors if flag 'ack' is set.
760  */
761 static void xgene_dma_cleanup_descriptors(struct xgene_dma_chan *chan)
762 {
763 	struct xgene_dma_ring *ring = &chan->rx_ring;
764 	struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
765 	struct xgene_dma_desc_hw *desc_hw;
766 	struct list_head ld_completed;
767 	u8 status;
768 
769 	INIT_LIST_HEAD(&ld_completed);
770 
771 	spin_lock_bh(&chan->lock);
772 
773 	/* Clean already completed and acked descriptors */
774 	xgene_dma_clean_completed_descriptor(chan);
775 
776 	/* Move all completed descriptors to ld completed queue, in order */
777 	list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_running, node) {
778 		/* Get subsequent hw descriptor from DMA rx ring */
779 		desc_hw = &ring->desc_hw[ring->head];
780 
781 		/* Check if this descriptor has been completed */
782 		if (unlikely(le64_to_cpu(desc_hw->m0) ==
783 			     XGENE_DMA_DESC_EMPTY_SIGNATURE))
784 			break;
785 
786 		if (++ring->head == ring->slots)
787 			ring->head = 0;
788 
789 		/* Check if we have any error with DMA transactions */
790 		status = XGENE_DMA_DESC_STATUS(
791 				XGENE_DMA_DESC_ELERR_RD(le64_to_cpu(
792 							desc_hw->m0)),
793 				XGENE_DMA_DESC_LERR_RD(le64_to_cpu(
794 						       desc_hw->m0)));
795 		if (status) {
796 			/* Print the DMA error type */
797 			chan_err(chan, "%s\n", xgene_dma_desc_err[status]);
798 
799 			/*
800 			 * We have DMA transactions error here. Dump DMA Tx
801 			 * and Rx descriptors for this request */
802 			XGENE_DMA_DESC_DUMP(&desc_sw->desc1,
803 					    "X-Gene DMA TX DESC1: ");
804 
805 			if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC)
806 				XGENE_DMA_DESC_DUMP(&desc_sw->desc2,
807 						    "X-Gene DMA TX DESC2: ");
808 
809 			XGENE_DMA_DESC_DUMP(desc_hw,
810 					    "X-Gene DMA RX ERR DESC: ");
811 		}
812 
813 		/* Notify the hw about this completed descriptor */
814 		iowrite32(-1, ring->cmd);
815 
816 		/* Mark this hw descriptor as processed */
817 		desc_hw->m0 = cpu_to_le64(XGENE_DMA_DESC_EMPTY_SIGNATURE);
818 
819 		/*
820 		 * Decrement the pending transaction count
821 		 * as we have processed one
822 		 */
823 		chan->pending--;
824 
825 		/*
826 		 * Delete this node from ld running queue and append it to
827 		 * ld completed queue for further processing
828 		 */
829 		list_move_tail(&desc_sw->node, &ld_completed);
830 	}
831 
832 	/*
833 	 * Start any pending transactions automatically
834 	 * In the ideal case, we keep the DMA controller busy while we go
835 	 * ahead and free the descriptors below.
836 	 */
837 	xgene_chan_xfer_ld_pending(chan);
838 
839 	spin_unlock_bh(&chan->lock);
840 
841 	/* Run the callback for each descriptor, in order */
842 	list_for_each_entry_safe(desc_sw, _desc_sw, &ld_completed, node) {
843 		xgene_dma_run_tx_complete_actions(chan, desc_sw);
844 		xgene_dma_clean_running_descriptor(chan, desc_sw);
845 	}
846 }
847 
848 static int xgene_dma_alloc_chan_resources(struct dma_chan *dchan)
849 {
850 	struct xgene_dma_chan *chan = to_dma_chan(dchan);
851 
852 	/* Has this channel already been allocated? */
853 	if (chan->desc_pool)
854 		return 1;
855 
856 	chan->desc_pool = dma_pool_create(chan->name, chan->dev,
857 					  sizeof(struct xgene_dma_desc_sw),
858 					  0, 0);
859 	if (!chan->desc_pool) {
860 		chan_err(chan, "Failed to allocate descriptor pool\n");
861 		return -ENOMEM;
862 	}
863 
864 	chan_dbg(chan, "Allocate descripto pool\n");
865 
866 	return 1;
867 }
868 
869 /**
870  * xgene_dma_free_desc_list - Free all descriptors in a queue
871  * @chan: X-Gene DMA channel
872  * @list: the list to free
873  *
874  * LOCKING: must hold chan->lock
875  */
876 static void xgene_dma_free_desc_list(struct xgene_dma_chan *chan,
877 				     struct list_head *list)
878 {
879 	struct xgene_dma_desc_sw *desc, *_desc;
880 
881 	list_for_each_entry_safe(desc, _desc, list, node)
882 		xgene_dma_clean_descriptor(chan, desc);
883 }
884 
885 static void xgene_dma_free_chan_resources(struct dma_chan *dchan)
886 {
887 	struct xgene_dma_chan *chan = to_dma_chan(dchan);
888 
889 	chan_dbg(chan, "Free all resources\n");
890 
891 	if (!chan->desc_pool)
892 		return;
893 
894 	/* Process all running descriptor */
895 	xgene_dma_cleanup_descriptors(chan);
896 
897 	spin_lock_bh(&chan->lock);
898 
899 	/* Clean all link descriptor queues */
900 	xgene_dma_free_desc_list(chan, &chan->ld_pending);
901 	xgene_dma_free_desc_list(chan, &chan->ld_running);
902 	xgene_dma_free_desc_list(chan, &chan->ld_completed);
903 
904 	spin_unlock_bh(&chan->lock);
905 
906 	/* Delete this channel DMA pool */
907 	dma_pool_destroy(chan->desc_pool);
908 	chan->desc_pool = NULL;
909 }
910 
911 static struct dma_async_tx_descriptor *xgene_dma_prep_memcpy(
912 	struct dma_chan *dchan, dma_addr_t dst, dma_addr_t src,
913 	size_t len, unsigned long flags)
914 {
915 	struct xgene_dma_desc_sw *first = NULL, *new;
916 	struct xgene_dma_chan *chan;
917 	size_t copy;
918 
919 	if (unlikely(!dchan || !len))
920 		return NULL;
921 
922 	chan = to_dma_chan(dchan);
923 
924 	do {
925 		/* Allocate the link descriptor from DMA pool */
926 		new = xgene_dma_alloc_descriptor(chan);
927 		if (!new)
928 			goto fail;
929 
930 		/* Create the largest transaction possible */
931 		copy = min_t(size_t, len, XGENE_DMA_MAX_64B_DESC_BYTE_CNT);
932 
933 		/* Prepare DMA descriptor */
934 		xgene_dma_prep_cpy_desc(chan, new, dst, src, copy);
935 
936 		if (!first)
937 			first = new;
938 
939 		new->tx.cookie = 0;
940 		async_tx_ack(&new->tx);
941 
942 		/* Update metadata */
943 		len -= copy;
944 		dst += copy;
945 		src += copy;
946 
947 		/* Insert the link descriptor to the LD ring */
948 		list_add_tail(&new->node, &first->tx_list);
949 	} while (len);
950 
951 	new->tx.flags = flags; /* client is in control of this ack */
952 	new->tx.cookie = -EBUSY;
953 	list_splice(&first->tx_list, &new->tx_list);
954 
955 	return &new->tx;
956 
957 fail:
958 	if (!first)
959 		return NULL;
960 
961 	xgene_dma_free_desc_list(chan, &first->tx_list);
962 	return NULL;
963 }
964 
965 static struct dma_async_tx_descriptor *xgene_dma_prep_sg(
966 	struct dma_chan *dchan, struct scatterlist *dst_sg,
967 	u32 dst_nents, struct scatterlist *src_sg,
968 	u32 src_nents, unsigned long flags)
969 {
970 	struct xgene_dma_desc_sw *first = NULL, *new = NULL;
971 	struct xgene_dma_chan *chan;
972 	size_t dst_avail, src_avail;
973 	dma_addr_t dst, src;
974 	size_t len;
975 
976 	if (unlikely(!dchan))
977 		return NULL;
978 
979 	if (unlikely(!dst_nents || !src_nents))
980 		return NULL;
981 
982 	if (unlikely(!dst_sg || !src_sg))
983 		return NULL;
984 
985 	chan = to_dma_chan(dchan);
986 
987 	/* Get prepared for the loop */
988 	dst_avail = sg_dma_len(dst_sg);
989 	src_avail = sg_dma_len(src_sg);
990 	dst_nents--;
991 	src_nents--;
992 
993 	/* Run until we are out of scatterlist entries */
994 	while (true) {
995 		/* Create the largest transaction possible */
996 		len = min_t(size_t, src_avail, dst_avail);
997 		len = min_t(size_t, len, XGENE_DMA_MAX_64B_DESC_BYTE_CNT);
998 		if (len == 0)
999 			goto fetch;
1000 
1001 		dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - dst_avail;
1002 		src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - src_avail;
1003 
1004 		/* Allocate the link descriptor from DMA pool */
1005 		new = xgene_dma_alloc_descriptor(chan);
1006 		if (!new)
1007 			goto fail;
1008 
1009 		/* Prepare DMA descriptor */
1010 		xgene_dma_prep_cpy_desc(chan, new, dst, src, len);
1011 
1012 		if (!first)
1013 			first = new;
1014 
1015 		new->tx.cookie = 0;
1016 		async_tx_ack(&new->tx);
1017 
1018 		/* update metadata */
1019 		dst_avail -= len;
1020 		src_avail -= len;
1021 
1022 		/* Insert the link descriptor to the LD ring */
1023 		list_add_tail(&new->node, &first->tx_list);
1024 
1025 fetch:
1026 		/* fetch the next dst scatterlist entry */
1027 		if (dst_avail == 0) {
1028 			/* no more entries: we're done */
1029 			if (dst_nents == 0)
1030 				break;
1031 
1032 			/* fetch the next entry: if there are no more: done */
1033 			dst_sg = sg_next(dst_sg);
1034 			if (!dst_sg)
1035 				break;
1036 
1037 			dst_nents--;
1038 			dst_avail = sg_dma_len(dst_sg);
1039 		}
1040 
1041 		/* fetch the next src scatterlist entry */
1042 		if (src_avail == 0) {
1043 			/* no more entries: we're done */
1044 			if (src_nents == 0)
1045 				break;
1046 
1047 			/* fetch the next entry: if there are no more: done */
1048 			src_sg = sg_next(src_sg);
1049 			if (!src_sg)
1050 				break;
1051 
1052 			src_nents--;
1053 			src_avail = sg_dma_len(src_sg);
1054 		}
1055 	}
1056 
1057 	if (!new)
1058 		return NULL;
1059 
1060 	new->tx.flags = flags; /* client is in control of this ack */
1061 	new->tx.cookie = -EBUSY;
1062 	list_splice(&first->tx_list, &new->tx_list);
1063 
1064 	return &new->tx;
1065 fail:
1066 	if (!first)
1067 		return NULL;
1068 
1069 	xgene_dma_free_desc_list(chan, &first->tx_list);
1070 	return NULL;
1071 }
1072 
1073 static struct dma_async_tx_descriptor *xgene_dma_prep_xor(
1074 	struct dma_chan *dchan, dma_addr_t dst,	dma_addr_t *src,
1075 	u32 src_cnt, size_t len, unsigned long flags)
1076 {
1077 	struct xgene_dma_desc_sw *first = NULL, *new;
1078 	struct xgene_dma_chan *chan;
1079 	static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {
1080 				0x01, 0x01, 0x01, 0x01, 0x01};
1081 
1082 	if (unlikely(!dchan || !len))
1083 		return NULL;
1084 
1085 	chan = to_dma_chan(dchan);
1086 
1087 	do {
1088 		/* Allocate the link descriptor from DMA pool */
1089 		new = xgene_dma_alloc_descriptor(chan);
1090 		if (!new)
1091 			goto fail;
1092 
1093 		/* Prepare xor DMA descriptor */
1094 		xgene_dma_prep_xor_desc(chan, new, &dst, src,
1095 					src_cnt, &len, multi);
1096 
1097 		if (!first)
1098 			first = new;
1099 
1100 		new->tx.cookie = 0;
1101 		async_tx_ack(&new->tx);
1102 
1103 		/* Insert the link descriptor to the LD ring */
1104 		list_add_tail(&new->node, &first->tx_list);
1105 	} while (len);
1106 
1107 	new->tx.flags = flags; /* client is in control of this ack */
1108 	new->tx.cookie = -EBUSY;
1109 	list_splice(&first->tx_list, &new->tx_list);
1110 
1111 	return &new->tx;
1112 
1113 fail:
1114 	if (!first)
1115 		return NULL;
1116 
1117 	xgene_dma_free_desc_list(chan, &first->tx_list);
1118 	return NULL;
1119 }
1120 
1121 static struct dma_async_tx_descriptor *xgene_dma_prep_pq(
1122 	struct dma_chan *dchan, dma_addr_t *dst, dma_addr_t *src,
1123 	u32 src_cnt, const u8 *scf, size_t len, unsigned long flags)
1124 {
1125 	struct xgene_dma_desc_sw *first = NULL, *new;
1126 	struct xgene_dma_chan *chan;
1127 	size_t _len = len;
1128 	dma_addr_t _src[XGENE_DMA_MAX_XOR_SRC];
1129 	static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {0x01, 0x01, 0x01, 0x01, 0x01};
1130 
1131 	if (unlikely(!dchan || !len))
1132 		return NULL;
1133 
1134 	chan = to_dma_chan(dchan);
1135 
1136 	/*
1137 	 * Save source addresses on local variable, may be we have to
1138 	 * prepare two descriptor to generate P and Q if both enabled
1139 	 * in the flags by client
1140 	 */
1141 	memcpy(_src, src, sizeof(*src) * src_cnt);
1142 
1143 	if (flags & DMA_PREP_PQ_DISABLE_P)
1144 		len = 0;
1145 
1146 	if (flags & DMA_PREP_PQ_DISABLE_Q)
1147 		_len = 0;
1148 
1149 	do {
1150 		/* Allocate the link descriptor from DMA pool */
1151 		new = xgene_dma_alloc_descriptor(chan);
1152 		if (!new)
1153 			goto fail;
1154 
1155 		if (!first)
1156 			first = new;
1157 
1158 		new->tx.cookie = 0;
1159 		async_tx_ack(&new->tx);
1160 
1161 		/* Insert the link descriptor to the LD ring */
1162 		list_add_tail(&new->node, &first->tx_list);
1163 
1164 		/*
1165 		 * Prepare DMA descriptor to generate P,
1166 		 * if DMA_PREP_PQ_DISABLE_P flag is not set
1167 		 */
1168 		if (len) {
1169 			xgene_dma_prep_xor_desc(chan, new, &dst[0], src,
1170 						src_cnt, &len, multi);
1171 			continue;
1172 		}
1173 
1174 		/*
1175 		 * Prepare DMA descriptor to generate Q,
1176 		 * if DMA_PREP_PQ_DISABLE_Q flag is not set
1177 		 */
1178 		if (_len) {
1179 			xgene_dma_prep_xor_desc(chan, new, &dst[1], _src,
1180 						src_cnt, &_len, scf);
1181 		}
1182 	} while (len || _len);
1183 
1184 	new->tx.flags = flags; /* client is in control of this ack */
1185 	new->tx.cookie = -EBUSY;
1186 	list_splice(&first->tx_list, &new->tx_list);
1187 
1188 	return &new->tx;
1189 
1190 fail:
1191 	if (!first)
1192 		return NULL;
1193 
1194 	xgene_dma_free_desc_list(chan, &first->tx_list);
1195 	return NULL;
1196 }
1197 
1198 static void xgene_dma_issue_pending(struct dma_chan *dchan)
1199 {
1200 	struct xgene_dma_chan *chan = to_dma_chan(dchan);
1201 
1202 	spin_lock_bh(&chan->lock);
1203 	xgene_chan_xfer_ld_pending(chan);
1204 	spin_unlock_bh(&chan->lock);
1205 }
1206 
1207 static enum dma_status xgene_dma_tx_status(struct dma_chan *dchan,
1208 					   dma_cookie_t cookie,
1209 					   struct dma_tx_state *txstate)
1210 {
1211 	return dma_cookie_status(dchan, cookie, txstate);
1212 }
1213 
1214 static void xgene_dma_tasklet_cb(unsigned long data)
1215 {
1216 	struct xgene_dma_chan *chan = (struct xgene_dma_chan *)data;
1217 
1218 	/* Run all cleanup for descriptors which have been completed */
1219 	xgene_dma_cleanup_descriptors(chan);
1220 
1221 	/* Re-enable DMA channel IRQ */
1222 	enable_irq(chan->rx_irq);
1223 }
1224 
1225 static irqreturn_t xgene_dma_chan_ring_isr(int irq, void *id)
1226 {
1227 	struct xgene_dma_chan *chan = (struct xgene_dma_chan *)id;
1228 
1229 	BUG_ON(!chan);
1230 
1231 	/*
1232 	 * Disable DMA channel IRQ until we process completed
1233 	 * descriptors
1234 	 */
1235 	disable_irq_nosync(chan->rx_irq);
1236 
1237 	/*
1238 	 * Schedule the tasklet to handle all cleanup of the current
1239 	 * transaction. It will start a new transaction if there is
1240 	 * one pending.
1241 	 */
1242 	tasklet_schedule(&chan->tasklet);
1243 
1244 	return IRQ_HANDLED;
1245 }
1246 
1247 static irqreturn_t xgene_dma_err_isr(int irq, void *id)
1248 {
1249 	struct xgene_dma *pdma = (struct xgene_dma *)id;
1250 	unsigned long int_mask;
1251 	u32 val, i;
1252 
1253 	val = ioread32(pdma->csr_dma + XGENE_DMA_INT);
1254 
1255 	/* Clear DMA interrupts */
1256 	iowrite32(val, pdma->csr_dma + XGENE_DMA_INT);
1257 
1258 	/* Print DMA error info */
1259 	int_mask = val >> XGENE_DMA_INT_MASK_SHIFT;
1260 	for_each_set_bit(i, &int_mask, ARRAY_SIZE(xgene_dma_err))
1261 		dev_err(pdma->dev,
1262 			"Interrupt status 0x%08X %s\n", val, xgene_dma_err[i]);
1263 
1264 	return IRQ_HANDLED;
1265 }
1266 
1267 static void xgene_dma_wr_ring_state(struct xgene_dma_ring *ring)
1268 {
1269 	int i;
1270 
1271 	iowrite32(ring->num, ring->pdma->csr_ring + XGENE_DMA_RING_STATE);
1272 
1273 	for (i = 0; i < XGENE_DMA_RING_NUM_CONFIG; i++)
1274 		iowrite32(ring->state[i], ring->pdma->csr_ring +
1275 			  XGENE_DMA_RING_STATE_WR_BASE + (i * 4));
1276 }
1277 
1278 static void xgene_dma_clr_ring_state(struct xgene_dma_ring *ring)
1279 {
1280 	memset(ring->state, 0, sizeof(u32) * XGENE_DMA_RING_NUM_CONFIG);
1281 	xgene_dma_wr_ring_state(ring);
1282 }
1283 
1284 static void xgene_dma_setup_ring(struct xgene_dma_ring *ring)
1285 {
1286 	void *ring_cfg = ring->state;
1287 	u64 addr = ring->desc_paddr;
1288 	u32 i, val;
1289 
1290 	ring->slots = ring->size / XGENE_DMA_RING_WQ_DESC_SIZE;
1291 
1292 	/* Clear DMA ring state */
1293 	xgene_dma_clr_ring_state(ring);
1294 
1295 	/* Set DMA ring type */
1296 	XGENE_DMA_RING_TYPE_SET(ring_cfg, XGENE_DMA_RING_TYPE_REGULAR);
1297 
1298 	if (ring->owner == XGENE_DMA_RING_OWNER_DMA) {
1299 		/* Set recombination buffer and timeout */
1300 		XGENE_DMA_RING_RECOMBBUF_SET(ring_cfg);
1301 		XGENE_DMA_RING_RECOMTIMEOUTL_SET(ring_cfg);
1302 		XGENE_DMA_RING_RECOMTIMEOUTH_SET(ring_cfg);
1303 	}
1304 
1305 	/* Initialize DMA ring state */
1306 	XGENE_DMA_RING_SELTHRSH_SET(ring_cfg);
1307 	XGENE_DMA_RING_ACCEPTLERR_SET(ring_cfg);
1308 	XGENE_DMA_RING_COHERENT_SET(ring_cfg);
1309 	XGENE_DMA_RING_ADDRL_SET(ring_cfg, addr);
1310 	XGENE_DMA_RING_ADDRH_SET(ring_cfg, addr);
1311 	XGENE_DMA_RING_SIZE_SET(ring_cfg, ring->cfgsize);
1312 
1313 	/* Write DMA ring configurations */
1314 	xgene_dma_wr_ring_state(ring);
1315 
1316 	/* Set DMA ring id */
1317 	iowrite32(XGENE_DMA_RING_ID_SETUP(ring->id),
1318 		  ring->pdma->csr_ring + XGENE_DMA_RING_ID);
1319 
1320 	/* Set DMA ring buffer */
1321 	iowrite32(XGENE_DMA_RING_ID_BUF_SETUP(ring->num),
1322 		  ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
1323 
1324 	if (ring->owner != XGENE_DMA_RING_OWNER_CPU)
1325 		return;
1326 
1327 	/* Set empty signature to DMA Rx ring descriptors */
1328 	for (i = 0; i < ring->slots; i++) {
1329 		struct xgene_dma_desc_hw *desc;
1330 
1331 		desc = &ring->desc_hw[i];
1332 		desc->m0 = cpu_to_le64(XGENE_DMA_DESC_EMPTY_SIGNATURE);
1333 	}
1334 
1335 	/* Enable DMA Rx ring interrupt */
1336 	val = ioread32(ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
1337 	XGENE_DMA_RING_NE_INT_MODE_SET(val, ring->buf_num);
1338 	iowrite32(val, ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
1339 }
1340 
1341 static void xgene_dma_clear_ring(struct xgene_dma_ring *ring)
1342 {
1343 	u32 ring_id, val;
1344 
1345 	if (ring->owner == XGENE_DMA_RING_OWNER_CPU) {
1346 		/* Disable DMA Rx ring interrupt */
1347 		val = ioread32(ring->pdma->csr_ring +
1348 			       XGENE_DMA_RING_NE_INT_MODE);
1349 		XGENE_DMA_RING_NE_INT_MODE_RESET(val, ring->buf_num);
1350 		iowrite32(val, ring->pdma->csr_ring +
1351 			  XGENE_DMA_RING_NE_INT_MODE);
1352 	}
1353 
1354 	/* Clear DMA ring state */
1355 	ring_id = XGENE_DMA_RING_ID_SETUP(ring->id);
1356 	iowrite32(ring_id, ring->pdma->csr_ring + XGENE_DMA_RING_ID);
1357 
1358 	iowrite32(0, ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
1359 	xgene_dma_clr_ring_state(ring);
1360 }
1361 
1362 static void xgene_dma_set_ring_cmd(struct xgene_dma_ring *ring)
1363 {
1364 	ring->cmd_base = ring->pdma->csr_ring_cmd +
1365 				XGENE_DMA_RING_CMD_BASE_OFFSET((ring->num -
1366 							  XGENE_DMA_RING_NUM));
1367 
1368 	ring->cmd = ring->cmd_base + XGENE_DMA_RING_CMD_OFFSET;
1369 }
1370 
1371 static int xgene_dma_get_ring_size(struct xgene_dma_chan *chan,
1372 				   enum xgene_dma_ring_cfgsize cfgsize)
1373 {
1374 	int size;
1375 
1376 	switch (cfgsize) {
1377 	case XGENE_DMA_RING_CFG_SIZE_512B:
1378 		size = 0x200;
1379 		break;
1380 	case XGENE_DMA_RING_CFG_SIZE_2KB:
1381 		size = 0x800;
1382 		break;
1383 	case XGENE_DMA_RING_CFG_SIZE_16KB:
1384 		size = 0x4000;
1385 		break;
1386 	case XGENE_DMA_RING_CFG_SIZE_64KB:
1387 		size = 0x10000;
1388 		break;
1389 	case XGENE_DMA_RING_CFG_SIZE_512KB:
1390 		size = 0x80000;
1391 		break;
1392 	default:
1393 		chan_err(chan, "Unsupported cfg ring size %d\n", cfgsize);
1394 		return -EINVAL;
1395 	}
1396 
1397 	return size;
1398 }
1399 
1400 static void xgene_dma_delete_ring_one(struct xgene_dma_ring *ring)
1401 {
1402 	/* Clear DMA ring configurations */
1403 	xgene_dma_clear_ring(ring);
1404 
1405 	/* De-allocate DMA ring descriptor */
1406 	if (ring->desc_vaddr) {
1407 		dma_free_coherent(ring->pdma->dev, ring->size,
1408 				  ring->desc_vaddr, ring->desc_paddr);
1409 		ring->desc_vaddr = NULL;
1410 	}
1411 }
1412 
1413 static void xgene_dma_delete_chan_rings(struct xgene_dma_chan *chan)
1414 {
1415 	xgene_dma_delete_ring_one(&chan->rx_ring);
1416 	xgene_dma_delete_ring_one(&chan->tx_ring);
1417 }
1418 
1419 static int xgene_dma_create_ring_one(struct xgene_dma_chan *chan,
1420 				     struct xgene_dma_ring *ring,
1421 				     enum xgene_dma_ring_cfgsize cfgsize)
1422 {
1423 	/* Setup DMA ring descriptor variables */
1424 	ring->pdma = chan->pdma;
1425 	ring->cfgsize = cfgsize;
1426 	ring->num = chan->pdma->ring_num++;
1427 	ring->id = XGENE_DMA_RING_ID_GET(ring->owner, ring->buf_num);
1428 
1429 	ring->size = xgene_dma_get_ring_size(chan, cfgsize);
1430 	if (ring->size <= 0)
1431 		return ring->size;
1432 
1433 	/* Allocate memory for DMA ring descriptor */
1434 	ring->desc_vaddr = dma_zalloc_coherent(chan->dev, ring->size,
1435 					       &ring->desc_paddr, GFP_KERNEL);
1436 	if (!ring->desc_vaddr) {
1437 		chan_err(chan, "Failed to allocate ring desc\n");
1438 		return -ENOMEM;
1439 	}
1440 
1441 	/* Configure and enable DMA ring */
1442 	xgene_dma_set_ring_cmd(ring);
1443 	xgene_dma_setup_ring(ring);
1444 
1445 	return 0;
1446 }
1447 
1448 static int xgene_dma_create_chan_rings(struct xgene_dma_chan *chan)
1449 {
1450 	struct xgene_dma_ring *rx_ring = &chan->rx_ring;
1451 	struct xgene_dma_ring *tx_ring = &chan->tx_ring;
1452 	int ret;
1453 
1454 	/* Create DMA Rx ring descriptor */
1455 	rx_ring->owner = XGENE_DMA_RING_OWNER_CPU;
1456 	rx_ring->buf_num = XGENE_DMA_CPU_BUFNUM + chan->id;
1457 
1458 	ret = xgene_dma_create_ring_one(chan, rx_ring,
1459 					XGENE_DMA_RING_CFG_SIZE_64KB);
1460 	if (ret)
1461 		return ret;
1462 
1463 	chan_dbg(chan, "Rx ring id 0x%X num %d desc 0x%p\n",
1464 		 rx_ring->id, rx_ring->num, rx_ring->desc_vaddr);
1465 
1466 	/* Create DMA Tx ring descriptor */
1467 	tx_ring->owner = XGENE_DMA_RING_OWNER_DMA;
1468 	tx_ring->buf_num = XGENE_DMA_BUFNUM + chan->id;
1469 
1470 	ret = xgene_dma_create_ring_one(chan, tx_ring,
1471 					XGENE_DMA_RING_CFG_SIZE_64KB);
1472 	if (ret) {
1473 		xgene_dma_delete_ring_one(rx_ring);
1474 		return ret;
1475 	}
1476 
1477 	tx_ring->dst_ring_num = XGENE_DMA_RING_DST_ID(rx_ring->num);
1478 
1479 	chan_dbg(chan,
1480 		 "Tx ring id 0x%X num %d desc 0x%p\n",
1481 		 tx_ring->id, tx_ring->num, tx_ring->desc_vaddr);
1482 
1483 	/* Set the max outstanding request possible to this channel */
1484 	chan->max_outstanding = rx_ring->slots;
1485 
1486 	return ret;
1487 }
1488 
1489 static int xgene_dma_init_rings(struct xgene_dma *pdma)
1490 {
1491 	int ret, i, j;
1492 
1493 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1494 		ret = xgene_dma_create_chan_rings(&pdma->chan[i]);
1495 		if (ret) {
1496 			for (j = 0; j < i; j++)
1497 				xgene_dma_delete_chan_rings(&pdma->chan[j]);
1498 			return ret;
1499 		}
1500 	}
1501 
1502 	return ret;
1503 }
1504 
1505 static void xgene_dma_enable(struct xgene_dma *pdma)
1506 {
1507 	u32 val;
1508 
1509 	/* Configure and enable DMA engine */
1510 	val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
1511 	XGENE_DMA_CH_SETUP(val);
1512 	XGENE_DMA_ENABLE(val);
1513 	iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
1514 }
1515 
1516 static void xgene_dma_disable(struct xgene_dma *pdma)
1517 {
1518 	u32 val;
1519 
1520 	val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
1521 	XGENE_DMA_DISABLE(val);
1522 	iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
1523 }
1524 
1525 static void xgene_dma_mask_interrupts(struct xgene_dma *pdma)
1526 {
1527 	/*
1528 	 * Mask DMA ring overflow, underflow and
1529 	 * AXI write/read error interrupts
1530 	 */
1531 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1532 		  pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
1533 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1534 		  pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
1535 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1536 		  pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
1537 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1538 		  pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
1539 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1540 		  pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
1541 
1542 	/* Mask DMA error interrupts */
1543 	iowrite32(XGENE_DMA_INT_ALL_MASK, pdma->csr_dma + XGENE_DMA_INT_MASK);
1544 }
1545 
1546 static void xgene_dma_unmask_interrupts(struct xgene_dma *pdma)
1547 {
1548 	/*
1549 	 * Unmask DMA ring overflow, underflow and
1550 	 * AXI write/read error interrupts
1551 	 */
1552 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1553 		  pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
1554 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1555 		  pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
1556 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1557 		  pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
1558 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1559 		  pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
1560 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1561 		  pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
1562 
1563 	/* Unmask DMA error interrupts */
1564 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1565 		  pdma->csr_dma + XGENE_DMA_INT_MASK);
1566 }
1567 
1568 static void xgene_dma_init_hw(struct xgene_dma *pdma)
1569 {
1570 	u32 val;
1571 
1572 	/* Associate DMA ring to corresponding ring HW */
1573 	iowrite32(XGENE_DMA_ASSOC_RING_MNGR1,
1574 		  pdma->csr_dma + XGENE_DMA_CFG_RING_WQ_ASSOC);
1575 
1576 	/* Configure RAID6 polynomial control setting */
1577 	if (is_pq_enabled(pdma))
1578 		iowrite32(XGENE_DMA_RAID6_MULTI_CTRL(0x1D),
1579 			  pdma->csr_dma + XGENE_DMA_RAID6_CONT);
1580 	else
1581 		dev_info(pdma->dev, "PQ is disabled in HW\n");
1582 
1583 	xgene_dma_enable(pdma);
1584 	xgene_dma_unmask_interrupts(pdma);
1585 
1586 	/* Get DMA id and version info */
1587 	val = ioread32(pdma->csr_dma + XGENE_DMA_IPBRR);
1588 
1589 	/* DMA device info */
1590 	dev_info(pdma->dev,
1591 		 "X-Gene DMA v%d.%02d.%02d driver registered %d channels",
1592 		 XGENE_DMA_REV_NO_RD(val), XGENE_DMA_BUS_ID_RD(val),
1593 		 XGENE_DMA_DEV_ID_RD(val), XGENE_DMA_MAX_CHANNEL);
1594 }
1595 
1596 static int xgene_dma_init_ring_mngr(struct xgene_dma *pdma)
1597 {
1598 	if (ioread32(pdma->csr_ring + XGENE_DMA_RING_CLKEN) &&
1599 	    (!ioread32(pdma->csr_ring + XGENE_DMA_RING_SRST)))
1600 		return 0;
1601 
1602 	iowrite32(0x3, pdma->csr_ring + XGENE_DMA_RING_CLKEN);
1603 	iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_SRST);
1604 
1605 	/* Bring up memory */
1606 	iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
1607 
1608 	/* Force a barrier */
1609 	ioread32(pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
1610 
1611 	/* reset may take up to 1ms */
1612 	usleep_range(1000, 1100);
1613 
1614 	if (ioread32(pdma->csr_ring + XGENE_DMA_RING_BLK_MEM_RDY)
1615 		!= XGENE_DMA_RING_BLK_MEM_RDY_VAL) {
1616 		dev_err(pdma->dev,
1617 			"Failed to release ring mngr memory from shutdown\n");
1618 		return -ENODEV;
1619 	}
1620 
1621 	/* program threshold set 1 and all hysteresis */
1622 	iowrite32(XGENE_DMA_RING_THRESLD0_SET1_VAL,
1623 		  pdma->csr_ring + XGENE_DMA_RING_THRESLD0_SET1);
1624 	iowrite32(XGENE_DMA_RING_THRESLD1_SET1_VAL,
1625 		  pdma->csr_ring + XGENE_DMA_RING_THRESLD1_SET1);
1626 	iowrite32(XGENE_DMA_RING_HYSTERESIS_VAL,
1627 		  pdma->csr_ring + XGENE_DMA_RING_HYSTERESIS);
1628 
1629 	/* Enable QPcore and assign error queue */
1630 	iowrite32(XGENE_DMA_RING_ENABLE,
1631 		  pdma->csr_ring + XGENE_DMA_RING_CONFIG);
1632 
1633 	return 0;
1634 }
1635 
1636 static int xgene_dma_init_mem(struct xgene_dma *pdma)
1637 {
1638 	int ret;
1639 
1640 	ret = xgene_dma_init_ring_mngr(pdma);
1641 	if (ret)
1642 		return ret;
1643 
1644 	/* Bring up memory */
1645 	iowrite32(0x0, pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
1646 
1647 	/* Force a barrier */
1648 	ioread32(pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
1649 
1650 	/* reset may take up to 1ms */
1651 	usleep_range(1000, 1100);
1652 
1653 	if (ioread32(pdma->csr_dma + XGENE_DMA_BLK_MEM_RDY)
1654 		!= XGENE_DMA_BLK_MEM_RDY_VAL) {
1655 		dev_err(pdma->dev,
1656 			"Failed to release DMA memory from shutdown\n");
1657 		return -ENODEV;
1658 	}
1659 
1660 	return 0;
1661 }
1662 
1663 static int xgene_dma_request_irqs(struct xgene_dma *pdma)
1664 {
1665 	struct xgene_dma_chan *chan;
1666 	int ret, i, j;
1667 
1668 	/* Register DMA error irq */
1669 	ret = devm_request_irq(pdma->dev, pdma->err_irq, xgene_dma_err_isr,
1670 			       0, "dma_error", pdma);
1671 	if (ret) {
1672 		dev_err(pdma->dev,
1673 			"Failed to register error IRQ %d\n", pdma->err_irq);
1674 		return ret;
1675 	}
1676 
1677 	/* Register DMA channel rx irq */
1678 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1679 		chan = &pdma->chan[i];
1680 		ret = devm_request_irq(chan->dev, chan->rx_irq,
1681 				       xgene_dma_chan_ring_isr,
1682 				       0, chan->name, chan);
1683 		if (ret) {
1684 			chan_err(chan, "Failed to register Rx IRQ %d\n",
1685 				 chan->rx_irq);
1686 			devm_free_irq(pdma->dev, pdma->err_irq, pdma);
1687 
1688 			for (j = 0; j < i; j++) {
1689 				chan = &pdma->chan[i];
1690 				devm_free_irq(chan->dev, chan->rx_irq, chan);
1691 			}
1692 
1693 			return ret;
1694 		}
1695 	}
1696 
1697 	return 0;
1698 }
1699 
1700 static void xgene_dma_free_irqs(struct xgene_dma *pdma)
1701 {
1702 	struct xgene_dma_chan *chan;
1703 	int i;
1704 
1705 	/* Free DMA device error irq */
1706 	devm_free_irq(pdma->dev, pdma->err_irq, pdma);
1707 
1708 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1709 		chan = &pdma->chan[i];
1710 		devm_free_irq(chan->dev, chan->rx_irq, chan);
1711 	}
1712 }
1713 
1714 static void xgene_dma_set_caps(struct xgene_dma_chan *chan,
1715 			       struct dma_device *dma_dev)
1716 {
1717 	/* Initialize DMA device capability mask */
1718 	dma_cap_zero(dma_dev->cap_mask);
1719 
1720 	/* Set DMA device capability */
1721 	dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
1722 	dma_cap_set(DMA_SG, dma_dev->cap_mask);
1723 
1724 	/* Basically here, the X-Gene SoC DMA engine channel 0 supports XOR
1725 	 * and channel 1 supports XOR, PQ both. First thing here is we have
1726 	 * mechanism in hw to enable/disable PQ/XOR supports on channel 1,
1727 	 * we can make sure this by reading SoC Efuse register.
1728 	 * Second thing, we have hw errata that if we run channel 0 and
1729 	 * channel 1 simultaneously with executing XOR and PQ request,
1730 	 * suddenly DMA engine hangs, So here we enable XOR on channel 0 only
1731 	 * if XOR and PQ supports on channel 1 is disabled.
1732 	 */
1733 	if ((chan->id == XGENE_DMA_PQ_CHANNEL) &&
1734 	    is_pq_enabled(chan->pdma)) {
1735 		dma_cap_set(DMA_PQ, dma_dev->cap_mask);
1736 		dma_cap_set(DMA_XOR, dma_dev->cap_mask);
1737 	} else if ((chan->id == XGENE_DMA_XOR_CHANNEL) &&
1738 		   !is_pq_enabled(chan->pdma)) {
1739 		dma_cap_set(DMA_XOR, dma_dev->cap_mask);
1740 	}
1741 
1742 	/* Set base and prep routines */
1743 	dma_dev->dev = chan->dev;
1744 	dma_dev->device_alloc_chan_resources = xgene_dma_alloc_chan_resources;
1745 	dma_dev->device_free_chan_resources = xgene_dma_free_chan_resources;
1746 	dma_dev->device_issue_pending = xgene_dma_issue_pending;
1747 	dma_dev->device_tx_status = xgene_dma_tx_status;
1748 	dma_dev->device_prep_dma_memcpy = xgene_dma_prep_memcpy;
1749 	dma_dev->device_prep_dma_sg = xgene_dma_prep_sg;
1750 
1751 	if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
1752 		dma_dev->device_prep_dma_xor = xgene_dma_prep_xor;
1753 		dma_dev->max_xor = XGENE_DMA_MAX_XOR_SRC;
1754 		dma_dev->xor_align = DMAENGINE_ALIGN_64_BYTES;
1755 	}
1756 
1757 	if (dma_has_cap(DMA_PQ, dma_dev->cap_mask)) {
1758 		dma_dev->device_prep_dma_pq = xgene_dma_prep_pq;
1759 		dma_dev->max_pq = XGENE_DMA_MAX_XOR_SRC;
1760 		dma_dev->pq_align = DMAENGINE_ALIGN_64_BYTES;
1761 	}
1762 }
1763 
1764 static int xgene_dma_async_register(struct xgene_dma *pdma, int id)
1765 {
1766 	struct xgene_dma_chan *chan = &pdma->chan[id];
1767 	struct dma_device *dma_dev = &pdma->dma_dev[id];
1768 	int ret;
1769 
1770 	chan->dma_chan.device = dma_dev;
1771 
1772 	spin_lock_init(&chan->lock);
1773 	INIT_LIST_HEAD(&chan->ld_pending);
1774 	INIT_LIST_HEAD(&chan->ld_running);
1775 	INIT_LIST_HEAD(&chan->ld_completed);
1776 	tasklet_init(&chan->tasklet, xgene_dma_tasklet_cb,
1777 		     (unsigned long)chan);
1778 
1779 	chan->pending = 0;
1780 	chan->desc_pool = NULL;
1781 	dma_cookie_init(&chan->dma_chan);
1782 
1783 	/* Setup dma device capabilities and prep routines */
1784 	xgene_dma_set_caps(chan, dma_dev);
1785 
1786 	/* Initialize DMA device list head */
1787 	INIT_LIST_HEAD(&dma_dev->channels);
1788 	list_add_tail(&chan->dma_chan.device_node, &dma_dev->channels);
1789 
1790 	/* Register with Linux async DMA framework*/
1791 	ret = dma_async_device_register(dma_dev);
1792 	if (ret) {
1793 		chan_err(chan, "Failed to register async device %d", ret);
1794 		tasklet_kill(&chan->tasklet);
1795 
1796 		return ret;
1797 	}
1798 
1799 	/* DMA capability info */
1800 	dev_info(pdma->dev,
1801 		 "%s: CAPABILITY ( %s%s%s%s)\n", dma_chan_name(&chan->dma_chan),
1802 		 dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask) ? "MEMCPY " : "",
1803 		 dma_has_cap(DMA_SG, dma_dev->cap_mask) ? "SGCPY " : "",
1804 		 dma_has_cap(DMA_XOR, dma_dev->cap_mask) ? "XOR " : "",
1805 		 dma_has_cap(DMA_PQ, dma_dev->cap_mask) ? "PQ " : "");
1806 
1807 	return 0;
1808 }
1809 
1810 static int xgene_dma_init_async(struct xgene_dma *pdma)
1811 {
1812 	int ret, i, j;
1813 
1814 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL ; i++) {
1815 		ret = xgene_dma_async_register(pdma, i);
1816 		if (ret) {
1817 			for (j = 0; j < i; j++) {
1818 				dma_async_device_unregister(&pdma->dma_dev[j]);
1819 				tasklet_kill(&pdma->chan[j].tasklet);
1820 			}
1821 
1822 			return ret;
1823 		}
1824 	}
1825 
1826 	return ret;
1827 }
1828 
1829 static void xgene_dma_async_unregister(struct xgene_dma *pdma)
1830 {
1831 	int i;
1832 
1833 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
1834 		dma_async_device_unregister(&pdma->dma_dev[i]);
1835 }
1836 
1837 static void xgene_dma_init_channels(struct xgene_dma *pdma)
1838 {
1839 	struct xgene_dma_chan *chan;
1840 	int i;
1841 
1842 	pdma->ring_num = XGENE_DMA_RING_NUM;
1843 
1844 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1845 		chan = &pdma->chan[i];
1846 		chan->dev = pdma->dev;
1847 		chan->pdma = pdma;
1848 		chan->id = i;
1849 		snprintf(chan->name, sizeof(chan->name), "dmachan%d", chan->id);
1850 	}
1851 }
1852 
1853 static int xgene_dma_get_resources(struct platform_device *pdev,
1854 				   struct xgene_dma *pdma)
1855 {
1856 	struct resource *res;
1857 	int irq, i;
1858 
1859 	/* Get DMA csr region */
1860 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1861 	if (!res) {
1862 		dev_err(&pdev->dev, "Failed to get csr region\n");
1863 		return -ENXIO;
1864 	}
1865 
1866 	pdma->csr_dma = devm_ioremap(&pdev->dev, res->start,
1867 				     resource_size(res));
1868 	if (!pdma->csr_dma) {
1869 		dev_err(&pdev->dev, "Failed to ioremap csr region");
1870 		return -ENOMEM;
1871 	}
1872 
1873 	/* Get DMA ring csr region */
1874 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1875 	if (!res) {
1876 		dev_err(&pdev->dev, "Failed to get ring csr region\n");
1877 		return -ENXIO;
1878 	}
1879 
1880 	pdma->csr_ring =  devm_ioremap(&pdev->dev, res->start,
1881 				       resource_size(res));
1882 	if (!pdma->csr_ring) {
1883 		dev_err(&pdev->dev, "Failed to ioremap ring csr region");
1884 		return -ENOMEM;
1885 	}
1886 
1887 	/* Get DMA ring cmd csr region */
1888 	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
1889 	if (!res) {
1890 		dev_err(&pdev->dev, "Failed to get ring cmd csr region\n");
1891 		return -ENXIO;
1892 	}
1893 
1894 	pdma->csr_ring_cmd = devm_ioremap(&pdev->dev, res->start,
1895 					  resource_size(res));
1896 	if (!pdma->csr_ring_cmd) {
1897 		dev_err(&pdev->dev, "Failed to ioremap ring cmd csr region");
1898 		return -ENOMEM;
1899 	}
1900 
1901 	/* Get efuse csr region */
1902 	res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
1903 	if (!res) {
1904 		dev_err(&pdev->dev, "Failed to get efuse csr region\n");
1905 		return -ENXIO;
1906 	}
1907 
1908 	pdma->csr_efuse = devm_ioremap(&pdev->dev, res->start,
1909 				       resource_size(res));
1910 	if (!pdma->csr_efuse) {
1911 		dev_err(&pdev->dev, "Failed to ioremap efuse csr region");
1912 		return -ENOMEM;
1913 	}
1914 
1915 	/* Get DMA error interrupt */
1916 	irq = platform_get_irq(pdev, 0);
1917 	if (irq <= 0) {
1918 		dev_err(&pdev->dev, "Failed to get Error IRQ\n");
1919 		return -ENXIO;
1920 	}
1921 
1922 	pdma->err_irq = irq;
1923 
1924 	/* Get DMA Rx ring descriptor interrupts for all DMA channels */
1925 	for (i = 1; i <= XGENE_DMA_MAX_CHANNEL; i++) {
1926 		irq = platform_get_irq(pdev, i);
1927 		if (irq <= 0) {
1928 			dev_err(&pdev->dev, "Failed to get Rx IRQ\n");
1929 			return -ENXIO;
1930 		}
1931 
1932 		pdma->chan[i - 1].rx_irq = irq;
1933 	}
1934 
1935 	return 0;
1936 }
1937 
1938 static int xgene_dma_probe(struct platform_device *pdev)
1939 {
1940 	struct xgene_dma *pdma;
1941 	int ret, i;
1942 
1943 	pdma = devm_kzalloc(&pdev->dev, sizeof(*pdma), GFP_KERNEL);
1944 	if (!pdma)
1945 		return -ENOMEM;
1946 
1947 	pdma->dev = &pdev->dev;
1948 	platform_set_drvdata(pdev, pdma);
1949 
1950 	ret = xgene_dma_get_resources(pdev, pdma);
1951 	if (ret)
1952 		return ret;
1953 
1954 	pdma->clk = devm_clk_get(&pdev->dev, NULL);
1955 	if (IS_ERR(pdma->clk) && !ACPI_COMPANION(&pdev->dev)) {
1956 		dev_err(&pdev->dev, "Failed to get clk\n");
1957 		return PTR_ERR(pdma->clk);
1958 	}
1959 
1960 	/* Enable clk before accessing registers */
1961 	if (!IS_ERR(pdma->clk)) {
1962 		ret = clk_prepare_enable(pdma->clk);
1963 		if (ret) {
1964 			dev_err(&pdev->dev, "Failed to enable clk %d\n", ret);
1965 			return ret;
1966 		}
1967 	}
1968 
1969 	/* Remove DMA RAM out of shutdown */
1970 	ret = xgene_dma_init_mem(pdma);
1971 	if (ret)
1972 		goto err_clk_enable;
1973 
1974 	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(42));
1975 	if (ret) {
1976 		dev_err(&pdev->dev, "No usable DMA configuration\n");
1977 		goto err_dma_mask;
1978 	}
1979 
1980 	/* Initialize DMA channels software state */
1981 	xgene_dma_init_channels(pdma);
1982 
1983 	/* Configue DMA rings */
1984 	ret = xgene_dma_init_rings(pdma);
1985 	if (ret)
1986 		goto err_clk_enable;
1987 
1988 	ret = xgene_dma_request_irqs(pdma);
1989 	if (ret)
1990 		goto err_request_irq;
1991 
1992 	/* Configure and enable DMA engine */
1993 	xgene_dma_init_hw(pdma);
1994 
1995 	/* Register DMA device with linux async framework */
1996 	ret = xgene_dma_init_async(pdma);
1997 	if (ret)
1998 		goto err_async_init;
1999 
2000 	return 0;
2001 
2002 err_async_init:
2003 	xgene_dma_free_irqs(pdma);
2004 
2005 err_request_irq:
2006 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
2007 		xgene_dma_delete_chan_rings(&pdma->chan[i]);
2008 
2009 err_dma_mask:
2010 err_clk_enable:
2011 	if (!IS_ERR(pdma->clk))
2012 		clk_disable_unprepare(pdma->clk);
2013 
2014 	return ret;
2015 }
2016 
2017 static int xgene_dma_remove(struct platform_device *pdev)
2018 {
2019 	struct xgene_dma *pdma = platform_get_drvdata(pdev);
2020 	struct xgene_dma_chan *chan;
2021 	int i;
2022 
2023 	xgene_dma_async_unregister(pdma);
2024 
2025 	/* Mask interrupts and disable DMA engine */
2026 	xgene_dma_mask_interrupts(pdma);
2027 	xgene_dma_disable(pdma);
2028 	xgene_dma_free_irqs(pdma);
2029 
2030 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
2031 		chan = &pdma->chan[i];
2032 		tasklet_kill(&chan->tasklet);
2033 		xgene_dma_delete_chan_rings(chan);
2034 	}
2035 
2036 	if (!IS_ERR(pdma->clk))
2037 		clk_disable_unprepare(pdma->clk);
2038 
2039 	return 0;
2040 }
2041 
2042 #ifdef CONFIG_ACPI
2043 static const struct acpi_device_id xgene_dma_acpi_match_ptr[] = {
2044 	{"APMC0D43", 0},
2045 	{},
2046 };
2047 MODULE_DEVICE_TABLE(acpi, xgene_dma_acpi_match_ptr);
2048 #endif
2049 
2050 static const struct of_device_id xgene_dma_of_match_ptr[] = {
2051 	{.compatible = "apm,xgene-storm-dma",},
2052 	{},
2053 };
2054 MODULE_DEVICE_TABLE(of, xgene_dma_of_match_ptr);
2055 
2056 static struct platform_driver xgene_dma_driver = {
2057 	.probe = xgene_dma_probe,
2058 	.remove = xgene_dma_remove,
2059 	.driver = {
2060 		.name = "X-Gene-DMA",
2061 		.of_match_table = xgene_dma_of_match_ptr,
2062 		.acpi_match_table = ACPI_PTR(xgene_dma_acpi_match_ptr),
2063 	},
2064 };
2065 
2066 module_platform_driver(xgene_dma_driver);
2067 
2068 MODULE_DESCRIPTION("APM X-Gene SoC DMA driver");
2069 MODULE_AUTHOR("Rameshwar Prasad Sahu <rsahu@apm.com>");
2070 MODULE_AUTHOR("Loc Ho <lho@apm.com>");
2071 MODULE_LICENSE("GPL");
2072 MODULE_VERSION("1.0");
2073