xref: /linux/drivers/dma/xgene-dma.c (revision 11bfedff5594eef74617e6aa02986cf517526b98)
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/irq.h>
33 #include <linux/module.h>
34 #include <linux/of_device.h>
35 
36 #include "dmaengine.h"
37 
38 /* X-Gene DMA ring csr registers and bit definations */
39 #define XGENE_DMA_RING_CONFIG			0x04
40 #define XGENE_DMA_RING_ENABLE			BIT(31)
41 #define XGENE_DMA_RING_ID			0x08
42 #define XGENE_DMA_RING_ID_SETUP(v)		((v) | BIT(31))
43 #define XGENE_DMA_RING_ID_BUF			0x0C
44 #define XGENE_DMA_RING_ID_BUF_SETUP(v)		(((v) << 9) | BIT(21))
45 #define XGENE_DMA_RING_THRESLD0_SET1		0x30
46 #define XGENE_DMA_RING_THRESLD0_SET1_VAL	0X64
47 #define XGENE_DMA_RING_THRESLD1_SET1		0x34
48 #define XGENE_DMA_RING_THRESLD1_SET1_VAL	0xC8
49 #define XGENE_DMA_RING_HYSTERESIS		0x68
50 #define XGENE_DMA_RING_HYSTERESIS_VAL		0xFFFFFFFF
51 #define XGENE_DMA_RING_STATE			0x6C
52 #define XGENE_DMA_RING_STATE_WR_BASE		0x70
53 #define XGENE_DMA_RING_NE_INT_MODE		0x017C
54 #define XGENE_DMA_RING_NE_INT_MODE_SET(m, v)	\
55 	((m) = ((m) & ~BIT(31 - (v))) | BIT(31 - (v)))
56 #define XGENE_DMA_RING_NE_INT_MODE_RESET(m, v)	\
57 	((m) &= (~BIT(31 - (v))))
58 #define XGENE_DMA_RING_CLKEN			0xC208
59 #define XGENE_DMA_RING_SRST			0xC200
60 #define XGENE_DMA_RING_MEM_RAM_SHUTDOWN		0xD070
61 #define XGENE_DMA_RING_BLK_MEM_RDY		0xD074
62 #define XGENE_DMA_RING_BLK_MEM_RDY_VAL		0xFFFFFFFF
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 #define XGENE_DMA_RING_CMD_SM_OFFSET		0x8000
116 
117 /* X-Gene SoC EFUSE csr register and bit defination */
118 #define XGENE_SOC_JTAG1_SHADOW			0x18
119 #define XGENE_DMA_PQ_DISABLE_MASK		BIT(13)
120 
121 /* X-Gene DMA Descriptor format */
122 #define XGENE_DMA_DESC_NV_BIT			BIT_ULL(50)
123 #define XGENE_DMA_DESC_IN_BIT			BIT_ULL(55)
124 #define XGENE_DMA_DESC_C_BIT			BIT_ULL(63)
125 #define XGENE_DMA_DESC_DR_BIT			BIT_ULL(61)
126 #define XGENE_DMA_DESC_ELERR_POS		46
127 #define XGENE_DMA_DESC_RTYPE_POS		56
128 #define XGENE_DMA_DESC_LERR_POS			60
129 #define XGENE_DMA_DESC_BUFLEN_POS		48
130 #define XGENE_DMA_DESC_HOENQ_NUM_POS		48
131 #define XGENE_DMA_DESC_ELERR_RD(m)		\
132 	(((m) >> XGENE_DMA_DESC_ELERR_POS) & 0x3)
133 #define XGENE_DMA_DESC_LERR_RD(m)		\
134 	(((m) >> XGENE_DMA_DESC_LERR_POS) & 0x7)
135 #define XGENE_DMA_DESC_STATUS(elerr, lerr)	\
136 	(((elerr) << 4) | (lerr))
137 
138 /* X-Gene DMA descriptor empty s/w signature */
139 #define XGENE_DMA_DESC_EMPTY_SIGNATURE		~0ULL
140 
141 /* X-Gene DMA configurable parameters defines */
142 #define XGENE_DMA_RING_NUM		512
143 #define XGENE_DMA_BUFNUM		0x0
144 #define XGENE_DMA_CPU_BUFNUM		0x18
145 #define XGENE_DMA_RING_OWNER_DMA	0x03
146 #define XGENE_DMA_RING_OWNER_CPU	0x0F
147 #define XGENE_DMA_RING_TYPE_REGULAR	0x01
148 #define XGENE_DMA_RING_WQ_DESC_SIZE	32	/* 32 Bytes */
149 #define XGENE_DMA_RING_NUM_CONFIG	5
150 #define XGENE_DMA_MAX_CHANNEL		4
151 #define XGENE_DMA_XOR_CHANNEL		0
152 #define XGENE_DMA_PQ_CHANNEL		1
153 #define XGENE_DMA_MAX_BYTE_CNT		0x4000	/* 16 KB */
154 #define XGENE_DMA_MAX_64B_DESC_BYTE_CNT	0x14000	/* 80 KB */
155 #define XGENE_DMA_MAX_XOR_SRC		5
156 #define XGENE_DMA_16K_BUFFER_LEN_CODE	0x0
157 #define XGENE_DMA_INVALID_LEN_CODE	0x7800000000000000ULL
158 
159 /* X-Gene DMA descriptor error codes */
160 #define ERR_DESC_AXI			0x01
161 #define ERR_BAD_DESC			0x02
162 #define ERR_READ_DATA_AXI		0x03
163 #define ERR_WRITE_DATA_AXI		0x04
164 #define ERR_FBP_TIMEOUT			0x05
165 #define ERR_ECC				0x06
166 #define ERR_DIFF_SIZE			0x08
167 #define ERR_SCT_GAT_LEN			0x09
168 #define ERR_CRC_ERR			0x11
169 #define ERR_CHKSUM			0x12
170 #define ERR_DIF				0x13
171 
172 /* X-Gene DMA error interrupt codes */
173 #define ERR_DIF_SIZE_INT		0x0
174 #define ERR_GS_ERR_INT			0x1
175 #define ERR_FPB_TIMEO_INT		0x2
176 #define ERR_WFIFO_OVF_INT		0x3
177 #define ERR_RFIFO_OVF_INT		0x4
178 #define ERR_WR_TIMEO_INT		0x5
179 #define ERR_RD_TIMEO_INT		0x6
180 #define ERR_WR_ERR_INT			0x7
181 #define ERR_RD_ERR_INT			0x8
182 #define ERR_BAD_DESC_INT		0x9
183 #define ERR_DESC_DST_INT		0xA
184 #define ERR_DESC_SRC_INT		0xB
185 
186 /* X-Gene DMA flyby operation code */
187 #define FLYBY_2SRC_XOR			0x80
188 #define FLYBY_3SRC_XOR			0x90
189 #define FLYBY_4SRC_XOR			0xA0
190 #define FLYBY_5SRC_XOR			0xB0
191 
192 /* X-Gene DMA SW descriptor flags */
193 #define XGENE_DMA_FLAG_64B_DESC		BIT(0)
194 
195 /* Define to dump X-Gene DMA descriptor */
196 #define XGENE_DMA_DESC_DUMP(desc, m)	\
197 	print_hex_dump(KERN_ERR, (m),	\
198 			DUMP_PREFIX_ADDRESS, 16, 8, (desc), 32, 0)
199 
200 #define to_dma_desc_sw(tx)		\
201 	container_of(tx, struct xgene_dma_desc_sw, tx)
202 #define to_dma_chan(dchan)		\
203 	container_of(dchan, struct xgene_dma_chan, dma_chan)
204 
205 #define chan_dbg(chan, fmt, arg...)	\
206 	dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
207 #define chan_err(chan, fmt, arg...)	\
208 	dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
209 
210 struct xgene_dma_desc_hw {
211 	__le64 m0;
212 	__le64 m1;
213 	__le64 m2;
214 	__le64 m3;
215 };
216 
217 enum xgene_dma_ring_cfgsize {
218 	XGENE_DMA_RING_CFG_SIZE_512B,
219 	XGENE_DMA_RING_CFG_SIZE_2KB,
220 	XGENE_DMA_RING_CFG_SIZE_16KB,
221 	XGENE_DMA_RING_CFG_SIZE_64KB,
222 	XGENE_DMA_RING_CFG_SIZE_512KB,
223 	XGENE_DMA_RING_CFG_SIZE_INVALID
224 };
225 
226 struct xgene_dma_ring {
227 	struct xgene_dma *pdma;
228 	u8 buf_num;
229 	u16 id;
230 	u16 num;
231 	u16 head;
232 	u16 owner;
233 	u16 slots;
234 	u16 dst_ring_num;
235 	u32 size;
236 	void __iomem *cmd;
237 	void __iomem *cmd_base;
238 	dma_addr_t desc_paddr;
239 	u32 state[XGENE_DMA_RING_NUM_CONFIG];
240 	enum xgene_dma_ring_cfgsize cfgsize;
241 	union {
242 		void *desc_vaddr;
243 		struct xgene_dma_desc_hw *desc_hw;
244 	};
245 };
246 
247 struct xgene_dma_desc_sw {
248 	struct xgene_dma_desc_hw desc1;
249 	struct xgene_dma_desc_hw desc2;
250 	u32 flags;
251 	struct list_head node;
252 	struct list_head tx_list;
253 	struct dma_async_tx_descriptor tx;
254 };
255 
256 /**
257  * struct xgene_dma_chan - internal representation of an X-Gene DMA channel
258  * @dma_chan: dmaengine channel object member
259  * @pdma: X-Gene DMA device structure reference
260  * @dev: struct device reference for dma mapping api
261  * @id: raw id of this channel
262  * @rx_irq: channel IRQ
263  * @name: name of X-Gene DMA channel
264  * @lock: serializes enqueue/dequeue operations to the descriptor pool
265  * @pending: number of transaction request pushed to DMA controller for
266  *	execution, but still waiting for completion,
267  * @max_outstanding: max number of outstanding request we can push to channel
268  * @ld_pending: descriptors which are queued to run, but have not yet been
269  *	submitted to the hardware for execution
270  * @ld_running: descriptors which are currently being executing by the hardware
271  * @ld_completed: descriptors which have finished execution by the hardware.
272  *	These descriptors have already had their cleanup actions run. They
273  *	are waiting for the ACK bit to be set by the async tx API.
274  * @desc_pool: descriptor pool for DMA operations
275  * @tasklet: bottom half where all completed descriptors cleans
276  * @tx_ring: transmit ring descriptor that we use to prepare actual
277  *	descriptors for further executions
278  * @rx_ring: receive ring descriptor that we use to get completed DMA
279  *	descriptors during cleanup time
280  */
281 struct xgene_dma_chan {
282 	struct dma_chan dma_chan;
283 	struct xgene_dma *pdma;
284 	struct device *dev;
285 	int id;
286 	int rx_irq;
287 	char name[10];
288 	spinlock_t lock;
289 	int pending;
290 	int max_outstanding;
291 	struct list_head ld_pending;
292 	struct list_head ld_running;
293 	struct list_head ld_completed;
294 	struct dma_pool *desc_pool;
295 	struct tasklet_struct tasklet;
296 	struct xgene_dma_ring tx_ring;
297 	struct xgene_dma_ring rx_ring;
298 };
299 
300 /**
301  * struct xgene_dma - internal representation of an X-Gene DMA device
302  * @err_irq: DMA error irq number
303  * @ring_num: start id number for DMA ring
304  * @csr_dma: base for DMA register access
305  * @csr_ring: base for DMA ring register access
306  * @csr_ring_cmd: base for DMA ring command register access
307  * @csr_efuse: base for efuse register access
308  * @dma_dev: embedded struct dma_device
309  * @chan: reference to X-Gene DMA channels
310  */
311 struct xgene_dma {
312 	struct device *dev;
313 	struct clk *clk;
314 	int err_irq;
315 	int ring_num;
316 	void __iomem *csr_dma;
317 	void __iomem *csr_ring;
318 	void __iomem *csr_ring_cmd;
319 	void __iomem *csr_efuse;
320 	struct dma_device dma_dev[XGENE_DMA_MAX_CHANNEL];
321 	struct xgene_dma_chan chan[XGENE_DMA_MAX_CHANNEL];
322 };
323 
324 static const char * const xgene_dma_desc_err[] = {
325 	[ERR_DESC_AXI] = "AXI error when reading src/dst link list",
326 	[ERR_BAD_DESC] = "ERR or El_ERR fields not set to zero in desc",
327 	[ERR_READ_DATA_AXI] = "AXI error when reading data",
328 	[ERR_WRITE_DATA_AXI] = "AXI error when writing data",
329 	[ERR_FBP_TIMEOUT] = "Timeout on bufpool fetch",
330 	[ERR_ECC] = "ECC double bit error",
331 	[ERR_DIFF_SIZE] = "Bufpool too small to hold all the DIF result",
332 	[ERR_SCT_GAT_LEN] = "Gather and scatter data length not same",
333 	[ERR_CRC_ERR] = "CRC error",
334 	[ERR_CHKSUM] = "Checksum error",
335 	[ERR_DIF] = "DIF error",
336 };
337 
338 static const char * const xgene_dma_err[] = {
339 	[ERR_DIF_SIZE_INT] = "DIF size error",
340 	[ERR_GS_ERR_INT] = "Gather scatter not same size error",
341 	[ERR_FPB_TIMEO_INT] = "Free pool time out error",
342 	[ERR_WFIFO_OVF_INT] = "Write FIFO over flow error",
343 	[ERR_RFIFO_OVF_INT] = "Read FIFO over flow error",
344 	[ERR_WR_TIMEO_INT] = "Write time out error",
345 	[ERR_RD_TIMEO_INT] = "Read time out error",
346 	[ERR_WR_ERR_INT] = "HBF bus write error",
347 	[ERR_RD_ERR_INT] = "HBF bus read error",
348 	[ERR_BAD_DESC_INT] = "Ring descriptor HE0 not set error",
349 	[ERR_DESC_DST_INT] = "HFB reading dst link address error",
350 	[ERR_DESC_SRC_INT] = "HFB reading src link address error",
351 };
352 
353 static bool is_pq_enabled(struct xgene_dma *pdma)
354 {
355 	u32 val;
356 
357 	val = ioread32(pdma->csr_efuse + XGENE_SOC_JTAG1_SHADOW);
358 	return !(val & XGENE_DMA_PQ_DISABLE_MASK);
359 }
360 
361 static u64 xgene_dma_encode_len(size_t len)
362 {
363 	return (len < XGENE_DMA_MAX_BYTE_CNT) ?
364 		((u64)len << XGENE_DMA_DESC_BUFLEN_POS) :
365 		XGENE_DMA_16K_BUFFER_LEN_CODE;
366 }
367 
368 static u8 xgene_dma_encode_xor_flyby(u32 src_cnt)
369 {
370 	static u8 flyby_type[] = {
371 		FLYBY_2SRC_XOR, /* Dummy */
372 		FLYBY_2SRC_XOR, /* Dummy */
373 		FLYBY_2SRC_XOR,
374 		FLYBY_3SRC_XOR,
375 		FLYBY_4SRC_XOR,
376 		FLYBY_5SRC_XOR
377 	};
378 
379 	return flyby_type[src_cnt];
380 }
381 
382 static void xgene_dma_set_src_buffer(__le64 *ext8, size_t *len,
383 				     dma_addr_t *paddr)
384 {
385 	size_t nbytes = (*len < XGENE_DMA_MAX_BYTE_CNT) ?
386 			*len : XGENE_DMA_MAX_BYTE_CNT;
387 
388 	*ext8 |= cpu_to_le64(*paddr);
389 	*ext8 |= cpu_to_le64(xgene_dma_encode_len(nbytes));
390 	*len -= nbytes;
391 	*paddr += nbytes;
392 }
393 
394 static void xgene_dma_invalidate_buffer(__le64 *ext8)
395 {
396 	*ext8 |= cpu_to_le64(XGENE_DMA_INVALID_LEN_CODE);
397 }
398 
399 static __le64 *xgene_dma_lookup_ext8(struct xgene_dma_desc_hw *desc, int idx)
400 {
401 	switch (idx) {
402 	case 0:
403 		return &desc->m1;
404 	case 1:
405 		return &desc->m0;
406 	case 2:
407 		return &desc->m3;
408 	case 3:
409 		return &desc->m2;
410 	default:
411 		pr_err("Invalid dma descriptor index\n");
412 	}
413 
414 	return NULL;
415 }
416 
417 static void xgene_dma_init_desc(struct xgene_dma_desc_hw *desc,
418 				u16 dst_ring_num)
419 {
420 	desc->m0 |= cpu_to_le64(XGENE_DMA_DESC_IN_BIT);
421 	desc->m0 |= cpu_to_le64((u64)XGENE_DMA_RING_OWNER_DMA <<
422 				XGENE_DMA_DESC_RTYPE_POS);
423 	desc->m1 |= cpu_to_le64(XGENE_DMA_DESC_C_BIT);
424 	desc->m3 |= cpu_to_le64((u64)dst_ring_num <<
425 				XGENE_DMA_DESC_HOENQ_NUM_POS);
426 }
427 
428 static void xgene_dma_prep_cpy_desc(struct xgene_dma_chan *chan,
429 				    struct xgene_dma_desc_sw *desc_sw,
430 				    dma_addr_t dst, dma_addr_t src,
431 				    size_t len)
432 {
433 	struct xgene_dma_desc_hw *desc1, *desc2;
434 	int i;
435 
436 	/* Get 1st descriptor */
437 	desc1 = &desc_sw->desc1;
438 	xgene_dma_init_desc(desc1, chan->tx_ring.dst_ring_num);
439 
440 	/* Set destination address */
441 	desc1->m2 |= cpu_to_le64(XGENE_DMA_DESC_DR_BIT);
442 	desc1->m3 |= cpu_to_le64(dst);
443 
444 	/* Set 1st source address */
445 	xgene_dma_set_src_buffer(&desc1->m1, &len, &src);
446 
447 	if (!len)
448 		return;
449 
450 	/*
451 	 * We need to split this source buffer,
452 	 * and need to use 2nd descriptor
453 	 */
454 	desc2 = &desc_sw->desc2;
455 	desc1->m0 |= cpu_to_le64(XGENE_DMA_DESC_NV_BIT);
456 
457 	/* Set 2nd to 5th source address */
458 	for (i = 0; i < 4 && len; i++)
459 		xgene_dma_set_src_buffer(xgene_dma_lookup_ext8(desc2, i),
460 					 &len, &src);
461 
462 	/* Invalidate unused source address field */
463 	for (; i < 4; i++)
464 		xgene_dma_invalidate_buffer(xgene_dma_lookup_ext8(desc2, i));
465 
466 	/* Updated flag that we have prepared 64B descriptor */
467 	desc_sw->flags |= XGENE_DMA_FLAG_64B_DESC;
468 }
469 
470 static void xgene_dma_prep_xor_desc(struct xgene_dma_chan *chan,
471 				    struct xgene_dma_desc_sw *desc_sw,
472 				    dma_addr_t *dst, dma_addr_t *src,
473 				    u32 src_cnt, size_t *nbytes,
474 				    const u8 *scf)
475 {
476 	struct xgene_dma_desc_hw *desc1, *desc2;
477 	size_t len = *nbytes;
478 	int i;
479 
480 	desc1 = &desc_sw->desc1;
481 	desc2 = &desc_sw->desc2;
482 
483 	/* Initialize DMA descriptor */
484 	xgene_dma_init_desc(desc1, chan->tx_ring.dst_ring_num);
485 
486 	/* Set destination address */
487 	desc1->m2 |= cpu_to_le64(XGENE_DMA_DESC_DR_BIT);
488 	desc1->m3 |= cpu_to_le64(*dst);
489 
490 	/* We have multiple source addresses, so need to set NV bit*/
491 	desc1->m0 |= cpu_to_le64(XGENE_DMA_DESC_NV_BIT);
492 
493 	/* Set flyby opcode */
494 	desc1->m2 |= cpu_to_le64(xgene_dma_encode_xor_flyby(src_cnt));
495 
496 	/* Set 1st to 5th source addresses */
497 	for (i = 0; i < src_cnt; i++) {
498 		len = *nbytes;
499 		xgene_dma_set_src_buffer((i == 0) ? &desc1->m1 :
500 					 xgene_dma_lookup_ext8(desc2, i - 1),
501 					 &len, &src[i]);
502 		desc1->m2 |= cpu_to_le64((scf[i] << ((i + 1) * 8)));
503 	}
504 
505 	/* Update meta data */
506 	*nbytes = len;
507 	*dst += XGENE_DMA_MAX_BYTE_CNT;
508 
509 	/* We need always 64B descriptor to perform xor or pq operations */
510 	desc_sw->flags |= XGENE_DMA_FLAG_64B_DESC;
511 }
512 
513 static dma_cookie_t xgene_dma_tx_submit(struct dma_async_tx_descriptor *tx)
514 {
515 	struct xgene_dma_desc_sw *desc;
516 	struct xgene_dma_chan *chan;
517 	dma_cookie_t cookie;
518 
519 	if (unlikely(!tx))
520 		return -EINVAL;
521 
522 	chan = to_dma_chan(tx->chan);
523 	desc = to_dma_desc_sw(tx);
524 
525 	spin_lock_bh(&chan->lock);
526 
527 	cookie = dma_cookie_assign(tx);
528 
529 	/* Add this transaction list onto the tail of the pending queue */
530 	list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
531 
532 	spin_unlock_bh(&chan->lock);
533 
534 	return cookie;
535 }
536 
537 static void xgene_dma_clean_descriptor(struct xgene_dma_chan *chan,
538 				       struct xgene_dma_desc_sw *desc)
539 {
540 	list_del(&desc->node);
541 	chan_dbg(chan, "LD %p free\n", desc);
542 	dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
543 }
544 
545 static struct xgene_dma_desc_sw *xgene_dma_alloc_descriptor(
546 				 struct xgene_dma_chan *chan)
547 {
548 	struct xgene_dma_desc_sw *desc;
549 	dma_addr_t phys;
550 
551 	desc = dma_pool_zalloc(chan->desc_pool, GFP_NOWAIT, &phys);
552 	if (!desc) {
553 		chan_err(chan, "Failed to allocate LDs\n");
554 		return NULL;
555 	}
556 
557 	INIT_LIST_HEAD(&desc->tx_list);
558 	desc->tx.phys = phys;
559 	desc->tx.tx_submit = xgene_dma_tx_submit;
560 	dma_async_tx_descriptor_init(&desc->tx, &chan->dma_chan);
561 
562 	chan_dbg(chan, "LD %p allocated\n", desc);
563 
564 	return desc;
565 }
566 
567 /**
568  * xgene_dma_clean_completed_descriptor - free all descriptors which
569  * has been completed and acked
570  * @chan: X-Gene DMA channel
571  *
572  * This function is used on all completed and acked descriptors.
573  */
574 static void xgene_dma_clean_completed_descriptor(struct xgene_dma_chan *chan)
575 {
576 	struct xgene_dma_desc_sw *desc, *_desc;
577 
578 	/* Run the callback for each descriptor, in order */
579 	list_for_each_entry_safe(desc, _desc, &chan->ld_completed, node) {
580 		if (async_tx_test_ack(&desc->tx))
581 			xgene_dma_clean_descriptor(chan, desc);
582 	}
583 }
584 
585 /**
586  * xgene_dma_run_tx_complete_actions - cleanup a single link descriptor
587  * @chan: X-Gene DMA channel
588  * @desc: descriptor to cleanup and free
589  *
590  * This function is used on a descriptor which has been executed by the DMA
591  * controller. It will run any callbacks, submit any dependencies.
592  */
593 static void xgene_dma_run_tx_complete_actions(struct xgene_dma_chan *chan,
594 					      struct xgene_dma_desc_sw *desc)
595 {
596 	struct dma_async_tx_descriptor *tx = &desc->tx;
597 
598 	/*
599 	 * If this is not the last transaction in the group,
600 	 * then no need to complete cookie and run any callback as
601 	 * this is not the tx_descriptor which had been sent to caller
602 	 * of this DMA request
603 	 */
604 
605 	if (tx->cookie == 0)
606 		return;
607 
608 	dma_cookie_complete(tx);
609 
610 	/* Run the link descriptor callback function */
611 	dmaengine_desc_get_callback_invoke(tx, NULL);
612 
613 	dma_descriptor_unmap(tx);
614 
615 	/* Run any dependencies */
616 	dma_run_dependencies(tx);
617 }
618 
619 /**
620  * xgene_dma_clean_running_descriptor - move the completed descriptor from
621  * ld_running to ld_completed
622  * @chan: X-Gene DMA channel
623  * @desc: the descriptor which is completed
624  *
625  * Free the descriptor directly if acked by async_tx api,
626  * else move it to queue ld_completed.
627  */
628 static void xgene_dma_clean_running_descriptor(struct xgene_dma_chan *chan,
629 					       struct xgene_dma_desc_sw *desc)
630 {
631 	/* Remove from the list of running transactions */
632 	list_del(&desc->node);
633 
634 	/*
635 	 * the client is allowed to attach dependent operations
636 	 * until 'ack' is set
637 	 */
638 	if (!async_tx_test_ack(&desc->tx)) {
639 		/*
640 		 * Move this descriptor to the list of descriptors which is
641 		 * completed, but still awaiting the 'ack' bit to be set.
642 		 */
643 		list_add_tail(&desc->node, &chan->ld_completed);
644 		return;
645 	}
646 
647 	chan_dbg(chan, "LD %p free\n", desc);
648 	dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
649 }
650 
651 static void xgene_chan_xfer_request(struct xgene_dma_chan *chan,
652 				    struct xgene_dma_desc_sw *desc_sw)
653 {
654 	struct xgene_dma_ring *ring = &chan->tx_ring;
655 	struct xgene_dma_desc_hw *desc_hw;
656 
657 	/* Get hw descriptor from DMA tx ring */
658 	desc_hw = &ring->desc_hw[ring->head];
659 
660 	/*
661 	 * Increment the head count to point next
662 	 * descriptor for next time
663 	 */
664 	if (++ring->head == ring->slots)
665 		ring->head = 0;
666 
667 	/* Copy prepared sw descriptor data to hw descriptor */
668 	memcpy(desc_hw, &desc_sw->desc1, sizeof(*desc_hw));
669 
670 	/*
671 	 * Check if we have prepared 64B descriptor,
672 	 * in this case we need one more hw descriptor
673 	 */
674 	if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) {
675 		desc_hw = &ring->desc_hw[ring->head];
676 
677 		if (++ring->head == ring->slots)
678 			ring->head = 0;
679 
680 		memcpy(desc_hw, &desc_sw->desc2, sizeof(*desc_hw));
681 	}
682 
683 	/* Increment the pending transaction count */
684 	chan->pending += ((desc_sw->flags &
685 			  XGENE_DMA_FLAG_64B_DESC) ? 2 : 1);
686 
687 	/* Notify the hw that we have descriptor ready for execution */
688 	iowrite32((desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) ?
689 		  2 : 1, ring->cmd);
690 }
691 
692 /**
693  * xgene_chan_xfer_ld_pending - push any pending transactions to hw
694  * @chan : X-Gene DMA channel
695  *
696  * LOCKING: must hold chan->lock
697  */
698 static void xgene_chan_xfer_ld_pending(struct xgene_dma_chan *chan)
699 {
700 	struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
701 
702 	/*
703 	 * If the list of pending descriptors is empty, then we
704 	 * don't need to do any work at all
705 	 */
706 	if (list_empty(&chan->ld_pending)) {
707 		chan_dbg(chan, "No pending LDs\n");
708 		return;
709 	}
710 
711 	/*
712 	 * Move elements from the queue of pending transactions onto the list
713 	 * of running transactions and push it to hw for further executions
714 	 */
715 	list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_pending, node) {
716 		/*
717 		 * Check if have pushed max number of transactions to hw
718 		 * as capable, so let's stop here and will push remaining
719 		 * elements from pening ld queue after completing some
720 		 * descriptors that we have already pushed
721 		 */
722 		if (chan->pending >= chan->max_outstanding)
723 			return;
724 
725 		xgene_chan_xfer_request(chan, desc_sw);
726 
727 		/*
728 		 * Delete this element from ld pending queue and append it to
729 		 * ld running queue
730 		 */
731 		list_move_tail(&desc_sw->node, &chan->ld_running);
732 	}
733 }
734 
735 /**
736  * xgene_dma_cleanup_descriptors - cleanup link descriptors which are completed
737  * and move them to ld_completed to free until flag 'ack' is set
738  * @chan: X-Gene DMA channel
739  *
740  * This function is used on descriptors which have been executed by the DMA
741  * controller. It will run any callbacks, submit any dependencies, then
742  * free these descriptors if flag 'ack' is set.
743  */
744 static void xgene_dma_cleanup_descriptors(struct xgene_dma_chan *chan)
745 {
746 	struct xgene_dma_ring *ring = &chan->rx_ring;
747 	struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
748 	struct xgene_dma_desc_hw *desc_hw;
749 	struct list_head ld_completed;
750 	u8 status;
751 
752 	INIT_LIST_HEAD(&ld_completed);
753 
754 	spin_lock_bh(&chan->lock);
755 
756 	/* Clean already completed and acked descriptors */
757 	xgene_dma_clean_completed_descriptor(chan);
758 
759 	/* Move all completed descriptors to ld completed queue, in order */
760 	list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_running, node) {
761 		/* Get subsequent hw descriptor from DMA rx ring */
762 		desc_hw = &ring->desc_hw[ring->head];
763 
764 		/* Check if this descriptor has been completed */
765 		if (unlikely(le64_to_cpu(desc_hw->m0) ==
766 			     XGENE_DMA_DESC_EMPTY_SIGNATURE))
767 			break;
768 
769 		if (++ring->head == ring->slots)
770 			ring->head = 0;
771 
772 		/* Check if we have any error with DMA transactions */
773 		status = XGENE_DMA_DESC_STATUS(
774 				XGENE_DMA_DESC_ELERR_RD(le64_to_cpu(
775 							desc_hw->m0)),
776 				XGENE_DMA_DESC_LERR_RD(le64_to_cpu(
777 						       desc_hw->m0)));
778 		if (status) {
779 			/* Print the DMA error type */
780 			chan_err(chan, "%s\n", xgene_dma_desc_err[status]);
781 
782 			/*
783 			 * We have DMA transactions error here. Dump DMA Tx
784 			 * and Rx descriptors for this request */
785 			XGENE_DMA_DESC_DUMP(&desc_sw->desc1,
786 					    "X-Gene DMA TX DESC1: ");
787 
788 			if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC)
789 				XGENE_DMA_DESC_DUMP(&desc_sw->desc2,
790 						    "X-Gene DMA TX DESC2: ");
791 
792 			XGENE_DMA_DESC_DUMP(desc_hw,
793 					    "X-Gene DMA RX ERR DESC: ");
794 		}
795 
796 		/* Notify the hw about this completed descriptor */
797 		iowrite32(-1, ring->cmd);
798 
799 		/* Mark this hw descriptor as processed */
800 		desc_hw->m0 = cpu_to_le64(XGENE_DMA_DESC_EMPTY_SIGNATURE);
801 
802 		/*
803 		 * Decrement the pending transaction count
804 		 * as we have processed one
805 		 */
806 		chan->pending -= ((desc_sw->flags &
807 				  XGENE_DMA_FLAG_64B_DESC) ? 2 : 1);
808 
809 		/*
810 		 * Delete this node from ld running queue and append it to
811 		 * ld completed queue for further processing
812 		 */
813 		list_move_tail(&desc_sw->node, &ld_completed);
814 	}
815 
816 	/*
817 	 * Start any pending transactions automatically
818 	 * In the ideal case, we keep the DMA controller busy while we go
819 	 * ahead and free the descriptors below.
820 	 */
821 	xgene_chan_xfer_ld_pending(chan);
822 
823 	spin_unlock_bh(&chan->lock);
824 
825 	/* Run the callback for each descriptor, in order */
826 	list_for_each_entry_safe(desc_sw, _desc_sw, &ld_completed, node) {
827 		xgene_dma_run_tx_complete_actions(chan, desc_sw);
828 		xgene_dma_clean_running_descriptor(chan, desc_sw);
829 	}
830 }
831 
832 static int xgene_dma_alloc_chan_resources(struct dma_chan *dchan)
833 {
834 	struct xgene_dma_chan *chan = to_dma_chan(dchan);
835 
836 	/* Has this channel already been allocated? */
837 	if (chan->desc_pool)
838 		return 1;
839 
840 	chan->desc_pool = dma_pool_create(chan->name, chan->dev,
841 					  sizeof(struct xgene_dma_desc_sw),
842 					  0, 0);
843 	if (!chan->desc_pool) {
844 		chan_err(chan, "Failed to allocate descriptor pool\n");
845 		return -ENOMEM;
846 	}
847 
848 	chan_dbg(chan, "Allocate descripto pool\n");
849 
850 	return 1;
851 }
852 
853 /**
854  * xgene_dma_free_desc_list - Free all descriptors in a queue
855  * @chan: X-Gene DMA channel
856  * @list: the list to free
857  *
858  * LOCKING: must hold chan->lock
859  */
860 static void xgene_dma_free_desc_list(struct xgene_dma_chan *chan,
861 				     struct list_head *list)
862 {
863 	struct xgene_dma_desc_sw *desc, *_desc;
864 
865 	list_for_each_entry_safe(desc, _desc, list, node)
866 		xgene_dma_clean_descriptor(chan, desc);
867 }
868 
869 static void xgene_dma_free_chan_resources(struct dma_chan *dchan)
870 {
871 	struct xgene_dma_chan *chan = to_dma_chan(dchan);
872 
873 	chan_dbg(chan, "Free all resources\n");
874 
875 	if (!chan->desc_pool)
876 		return;
877 
878 	/* Process all running descriptor */
879 	xgene_dma_cleanup_descriptors(chan);
880 
881 	spin_lock_bh(&chan->lock);
882 
883 	/* Clean all link descriptor queues */
884 	xgene_dma_free_desc_list(chan, &chan->ld_pending);
885 	xgene_dma_free_desc_list(chan, &chan->ld_running);
886 	xgene_dma_free_desc_list(chan, &chan->ld_completed);
887 
888 	spin_unlock_bh(&chan->lock);
889 
890 	/* Delete this channel DMA pool */
891 	dma_pool_destroy(chan->desc_pool);
892 	chan->desc_pool = NULL;
893 }
894 
895 static struct dma_async_tx_descriptor *xgene_dma_prep_sg(
896 	struct dma_chan *dchan, struct scatterlist *dst_sg,
897 	u32 dst_nents, struct scatterlist *src_sg,
898 	u32 src_nents, unsigned long flags)
899 {
900 	struct xgene_dma_desc_sw *first = NULL, *new = NULL;
901 	struct xgene_dma_chan *chan;
902 	size_t dst_avail, src_avail;
903 	dma_addr_t dst, src;
904 	size_t len;
905 
906 	if (unlikely(!dchan))
907 		return NULL;
908 
909 	if (unlikely(!dst_nents || !src_nents))
910 		return NULL;
911 
912 	if (unlikely(!dst_sg || !src_sg))
913 		return NULL;
914 
915 	chan = to_dma_chan(dchan);
916 
917 	/* Get prepared for the loop */
918 	dst_avail = sg_dma_len(dst_sg);
919 	src_avail = sg_dma_len(src_sg);
920 	dst_nents--;
921 	src_nents--;
922 
923 	/* Run until we are out of scatterlist entries */
924 	while (true) {
925 		/* Create the largest transaction possible */
926 		len = min_t(size_t, src_avail, dst_avail);
927 		len = min_t(size_t, len, XGENE_DMA_MAX_64B_DESC_BYTE_CNT);
928 		if (len == 0)
929 			goto fetch;
930 
931 		dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - dst_avail;
932 		src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - src_avail;
933 
934 		/* Allocate the link descriptor from DMA pool */
935 		new = xgene_dma_alloc_descriptor(chan);
936 		if (!new)
937 			goto fail;
938 
939 		/* Prepare DMA descriptor */
940 		xgene_dma_prep_cpy_desc(chan, new, dst, src, len);
941 
942 		if (!first)
943 			first = new;
944 
945 		new->tx.cookie = 0;
946 		async_tx_ack(&new->tx);
947 
948 		/* update metadata */
949 		dst_avail -= len;
950 		src_avail -= len;
951 
952 		/* Insert the link descriptor to the LD ring */
953 		list_add_tail(&new->node, &first->tx_list);
954 
955 fetch:
956 		/* fetch the next dst scatterlist entry */
957 		if (dst_avail == 0) {
958 			/* no more entries: we're done */
959 			if (dst_nents == 0)
960 				break;
961 
962 			/* fetch the next entry: if there are no more: done */
963 			dst_sg = sg_next(dst_sg);
964 			if (!dst_sg)
965 				break;
966 
967 			dst_nents--;
968 			dst_avail = sg_dma_len(dst_sg);
969 		}
970 
971 		/* fetch the next src scatterlist entry */
972 		if (src_avail == 0) {
973 			/* no more entries: we're done */
974 			if (src_nents == 0)
975 				break;
976 
977 			/* fetch the next entry: if there are no more: done */
978 			src_sg = sg_next(src_sg);
979 			if (!src_sg)
980 				break;
981 
982 			src_nents--;
983 			src_avail = sg_dma_len(src_sg);
984 		}
985 	}
986 
987 	if (!new)
988 		return NULL;
989 
990 	new->tx.flags = flags; /* client is in control of this ack */
991 	new->tx.cookie = -EBUSY;
992 	list_splice(&first->tx_list, &new->tx_list);
993 
994 	return &new->tx;
995 fail:
996 	if (!first)
997 		return NULL;
998 
999 	xgene_dma_free_desc_list(chan, &first->tx_list);
1000 	return NULL;
1001 }
1002 
1003 static struct dma_async_tx_descriptor *xgene_dma_prep_xor(
1004 	struct dma_chan *dchan, dma_addr_t dst,	dma_addr_t *src,
1005 	u32 src_cnt, size_t len, unsigned long flags)
1006 {
1007 	struct xgene_dma_desc_sw *first = NULL, *new;
1008 	struct xgene_dma_chan *chan;
1009 	static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {
1010 				0x01, 0x01, 0x01, 0x01, 0x01};
1011 
1012 	if (unlikely(!dchan || !len))
1013 		return NULL;
1014 
1015 	chan = to_dma_chan(dchan);
1016 
1017 	do {
1018 		/* Allocate the link descriptor from DMA pool */
1019 		new = xgene_dma_alloc_descriptor(chan);
1020 		if (!new)
1021 			goto fail;
1022 
1023 		/* Prepare xor DMA descriptor */
1024 		xgene_dma_prep_xor_desc(chan, new, &dst, src,
1025 					src_cnt, &len, multi);
1026 
1027 		if (!first)
1028 			first = new;
1029 
1030 		new->tx.cookie = 0;
1031 		async_tx_ack(&new->tx);
1032 
1033 		/* Insert the link descriptor to the LD ring */
1034 		list_add_tail(&new->node, &first->tx_list);
1035 	} while (len);
1036 
1037 	new->tx.flags = flags; /* client is in control of this ack */
1038 	new->tx.cookie = -EBUSY;
1039 	list_splice(&first->tx_list, &new->tx_list);
1040 
1041 	return &new->tx;
1042 
1043 fail:
1044 	if (!first)
1045 		return NULL;
1046 
1047 	xgene_dma_free_desc_list(chan, &first->tx_list);
1048 	return NULL;
1049 }
1050 
1051 static struct dma_async_tx_descriptor *xgene_dma_prep_pq(
1052 	struct dma_chan *dchan, dma_addr_t *dst, dma_addr_t *src,
1053 	u32 src_cnt, const u8 *scf, size_t len, unsigned long flags)
1054 {
1055 	struct xgene_dma_desc_sw *first = NULL, *new;
1056 	struct xgene_dma_chan *chan;
1057 	size_t _len = len;
1058 	dma_addr_t _src[XGENE_DMA_MAX_XOR_SRC];
1059 	static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {0x01, 0x01, 0x01, 0x01, 0x01};
1060 
1061 	if (unlikely(!dchan || !len))
1062 		return NULL;
1063 
1064 	chan = to_dma_chan(dchan);
1065 
1066 	/*
1067 	 * Save source addresses on local variable, may be we have to
1068 	 * prepare two descriptor to generate P and Q if both enabled
1069 	 * in the flags by client
1070 	 */
1071 	memcpy(_src, src, sizeof(*src) * src_cnt);
1072 
1073 	if (flags & DMA_PREP_PQ_DISABLE_P)
1074 		len = 0;
1075 
1076 	if (flags & DMA_PREP_PQ_DISABLE_Q)
1077 		_len = 0;
1078 
1079 	do {
1080 		/* Allocate the link descriptor from DMA pool */
1081 		new = xgene_dma_alloc_descriptor(chan);
1082 		if (!new)
1083 			goto fail;
1084 
1085 		if (!first)
1086 			first = new;
1087 
1088 		new->tx.cookie = 0;
1089 		async_tx_ack(&new->tx);
1090 
1091 		/* Insert the link descriptor to the LD ring */
1092 		list_add_tail(&new->node, &first->tx_list);
1093 
1094 		/*
1095 		 * Prepare DMA descriptor to generate P,
1096 		 * if DMA_PREP_PQ_DISABLE_P flag is not set
1097 		 */
1098 		if (len) {
1099 			xgene_dma_prep_xor_desc(chan, new, &dst[0], src,
1100 						src_cnt, &len, multi);
1101 			continue;
1102 		}
1103 
1104 		/*
1105 		 * Prepare DMA descriptor to generate Q,
1106 		 * if DMA_PREP_PQ_DISABLE_Q flag is not set
1107 		 */
1108 		if (_len) {
1109 			xgene_dma_prep_xor_desc(chan, new, &dst[1], _src,
1110 						src_cnt, &_len, scf);
1111 		}
1112 	} while (len || _len);
1113 
1114 	new->tx.flags = flags; /* client is in control of this ack */
1115 	new->tx.cookie = -EBUSY;
1116 	list_splice(&first->tx_list, &new->tx_list);
1117 
1118 	return &new->tx;
1119 
1120 fail:
1121 	if (!first)
1122 		return NULL;
1123 
1124 	xgene_dma_free_desc_list(chan, &first->tx_list);
1125 	return NULL;
1126 }
1127 
1128 static void xgene_dma_issue_pending(struct dma_chan *dchan)
1129 {
1130 	struct xgene_dma_chan *chan = to_dma_chan(dchan);
1131 
1132 	spin_lock_bh(&chan->lock);
1133 	xgene_chan_xfer_ld_pending(chan);
1134 	spin_unlock_bh(&chan->lock);
1135 }
1136 
1137 static enum dma_status xgene_dma_tx_status(struct dma_chan *dchan,
1138 					   dma_cookie_t cookie,
1139 					   struct dma_tx_state *txstate)
1140 {
1141 	return dma_cookie_status(dchan, cookie, txstate);
1142 }
1143 
1144 static void xgene_dma_tasklet_cb(unsigned long data)
1145 {
1146 	struct xgene_dma_chan *chan = (struct xgene_dma_chan *)data;
1147 
1148 	/* Run all cleanup for descriptors which have been completed */
1149 	xgene_dma_cleanup_descriptors(chan);
1150 
1151 	/* Re-enable DMA channel IRQ */
1152 	enable_irq(chan->rx_irq);
1153 }
1154 
1155 static irqreturn_t xgene_dma_chan_ring_isr(int irq, void *id)
1156 {
1157 	struct xgene_dma_chan *chan = (struct xgene_dma_chan *)id;
1158 
1159 	BUG_ON(!chan);
1160 
1161 	/*
1162 	 * Disable DMA channel IRQ until we process completed
1163 	 * descriptors
1164 	 */
1165 	disable_irq_nosync(chan->rx_irq);
1166 
1167 	/*
1168 	 * Schedule the tasklet to handle all cleanup of the current
1169 	 * transaction. It will start a new transaction if there is
1170 	 * one pending.
1171 	 */
1172 	tasklet_schedule(&chan->tasklet);
1173 
1174 	return IRQ_HANDLED;
1175 }
1176 
1177 static irqreturn_t xgene_dma_err_isr(int irq, void *id)
1178 {
1179 	struct xgene_dma *pdma = (struct xgene_dma *)id;
1180 	unsigned long int_mask;
1181 	u32 val, i;
1182 
1183 	val = ioread32(pdma->csr_dma + XGENE_DMA_INT);
1184 
1185 	/* Clear DMA interrupts */
1186 	iowrite32(val, pdma->csr_dma + XGENE_DMA_INT);
1187 
1188 	/* Print DMA error info */
1189 	int_mask = val >> XGENE_DMA_INT_MASK_SHIFT;
1190 	for_each_set_bit(i, &int_mask, ARRAY_SIZE(xgene_dma_err))
1191 		dev_err(pdma->dev,
1192 			"Interrupt status 0x%08X %s\n", val, xgene_dma_err[i]);
1193 
1194 	return IRQ_HANDLED;
1195 }
1196 
1197 static void xgene_dma_wr_ring_state(struct xgene_dma_ring *ring)
1198 {
1199 	int i;
1200 
1201 	iowrite32(ring->num, ring->pdma->csr_ring + XGENE_DMA_RING_STATE);
1202 
1203 	for (i = 0; i < XGENE_DMA_RING_NUM_CONFIG; i++)
1204 		iowrite32(ring->state[i], ring->pdma->csr_ring +
1205 			  XGENE_DMA_RING_STATE_WR_BASE + (i * 4));
1206 }
1207 
1208 static void xgene_dma_clr_ring_state(struct xgene_dma_ring *ring)
1209 {
1210 	memset(ring->state, 0, sizeof(u32) * XGENE_DMA_RING_NUM_CONFIG);
1211 	xgene_dma_wr_ring_state(ring);
1212 }
1213 
1214 static void xgene_dma_setup_ring(struct xgene_dma_ring *ring)
1215 {
1216 	void *ring_cfg = ring->state;
1217 	u64 addr = ring->desc_paddr;
1218 	u32 i, val;
1219 
1220 	ring->slots = ring->size / XGENE_DMA_RING_WQ_DESC_SIZE;
1221 
1222 	/* Clear DMA ring state */
1223 	xgene_dma_clr_ring_state(ring);
1224 
1225 	/* Set DMA ring type */
1226 	XGENE_DMA_RING_TYPE_SET(ring_cfg, XGENE_DMA_RING_TYPE_REGULAR);
1227 
1228 	if (ring->owner == XGENE_DMA_RING_OWNER_DMA) {
1229 		/* Set recombination buffer and timeout */
1230 		XGENE_DMA_RING_RECOMBBUF_SET(ring_cfg);
1231 		XGENE_DMA_RING_RECOMTIMEOUTL_SET(ring_cfg);
1232 		XGENE_DMA_RING_RECOMTIMEOUTH_SET(ring_cfg);
1233 	}
1234 
1235 	/* Initialize DMA ring state */
1236 	XGENE_DMA_RING_SELTHRSH_SET(ring_cfg);
1237 	XGENE_DMA_RING_ACCEPTLERR_SET(ring_cfg);
1238 	XGENE_DMA_RING_COHERENT_SET(ring_cfg);
1239 	XGENE_DMA_RING_ADDRL_SET(ring_cfg, addr);
1240 	XGENE_DMA_RING_ADDRH_SET(ring_cfg, addr);
1241 	XGENE_DMA_RING_SIZE_SET(ring_cfg, ring->cfgsize);
1242 
1243 	/* Write DMA ring configurations */
1244 	xgene_dma_wr_ring_state(ring);
1245 
1246 	/* Set DMA ring id */
1247 	iowrite32(XGENE_DMA_RING_ID_SETUP(ring->id),
1248 		  ring->pdma->csr_ring + XGENE_DMA_RING_ID);
1249 
1250 	/* Set DMA ring buffer */
1251 	iowrite32(XGENE_DMA_RING_ID_BUF_SETUP(ring->num),
1252 		  ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
1253 
1254 	if (ring->owner != XGENE_DMA_RING_OWNER_CPU)
1255 		return;
1256 
1257 	/* Set empty signature to DMA Rx ring descriptors */
1258 	for (i = 0; i < ring->slots; i++) {
1259 		struct xgene_dma_desc_hw *desc;
1260 
1261 		desc = &ring->desc_hw[i];
1262 		desc->m0 = cpu_to_le64(XGENE_DMA_DESC_EMPTY_SIGNATURE);
1263 	}
1264 
1265 	/* Enable DMA Rx ring interrupt */
1266 	val = ioread32(ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
1267 	XGENE_DMA_RING_NE_INT_MODE_SET(val, ring->buf_num);
1268 	iowrite32(val, ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
1269 }
1270 
1271 static void xgene_dma_clear_ring(struct xgene_dma_ring *ring)
1272 {
1273 	u32 ring_id, val;
1274 
1275 	if (ring->owner == XGENE_DMA_RING_OWNER_CPU) {
1276 		/* Disable DMA Rx ring interrupt */
1277 		val = ioread32(ring->pdma->csr_ring +
1278 			       XGENE_DMA_RING_NE_INT_MODE);
1279 		XGENE_DMA_RING_NE_INT_MODE_RESET(val, ring->buf_num);
1280 		iowrite32(val, ring->pdma->csr_ring +
1281 			  XGENE_DMA_RING_NE_INT_MODE);
1282 	}
1283 
1284 	/* Clear DMA ring state */
1285 	ring_id = XGENE_DMA_RING_ID_SETUP(ring->id);
1286 	iowrite32(ring_id, ring->pdma->csr_ring + XGENE_DMA_RING_ID);
1287 
1288 	iowrite32(0, ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
1289 	xgene_dma_clr_ring_state(ring);
1290 }
1291 
1292 static void xgene_dma_set_ring_cmd(struct xgene_dma_ring *ring)
1293 {
1294 	ring->cmd_base = ring->pdma->csr_ring_cmd +
1295 				XGENE_DMA_RING_CMD_BASE_OFFSET((ring->num -
1296 							  XGENE_DMA_RING_NUM));
1297 
1298 	ring->cmd = ring->cmd_base + XGENE_DMA_RING_CMD_OFFSET;
1299 }
1300 
1301 static int xgene_dma_get_ring_size(struct xgene_dma_chan *chan,
1302 				   enum xgene_dma_ring_cfgsize cfgsize)
1303 {
1304 	int size;
1305 
1306 	switch (cfgsize) {
1307 	case XGENE_DMA_RING_CFG_SIZE_512B:
1308 		size = 0x200;
1309 		break;
1310 	case XGENE_DMA_RING_CFG_SIZE_2KB:
1311 		size = 0x800;
1312 		break;
1313 	case XGENE_DMA_RING_CFG_SIZE_16KB:
1314 		size = 0x4000;
1315 		break;
1316 	case XGENE_DMA_RING_CFG_SIZE_64KB:
1317 		size = 0x10000;
1318 		break;
1319 	case XGENE_DMA_RING_CFG_SIZE_512KB:
1320 		size = 0x80000;
1321 		break;
1322 	default:
1323 		chan_err(chan, "Unsupported cfg ring size %d\n", cfgsize);
1324 		return -EINVAL;
1325 	}
1326 
1327 	return size;
1328 }
1329 
1330 static void xgene_dma_delete_ring_one(struct xgene_dma_ring *ring)
1331 {
1332 	/* Clear DMA ring configurations */
1333 	xgene_dma_clear_ring(ring);
1334 
1335 	/* De-allocate DMA ring descriptor */
1336 	if (ring->desc_vaddr) {
1337 		dma_free_coherent(ring->pdma->dev, ring->size,
1338 				  ring->desc_vaddr, ring->desc_paddr);
1339 		ring->desc_vaddr = NULL;
1340 	}
1341 }
1342 
1343 static void xgene_dma_delete_chan_rings(struct xgene_dma_chan *chan)
1344 {
1345 	xgene_dma_delete_ring_one(&chan->rx_ring);
1346 	xgene_dma_delete_ring_one(&chan->tx_ring);
1347 }
1348 
1349 static int xgene_dma_create_ring_one(struct xgene_dma_chan *chan,
1350 				     struct xgene_dma_ring *ring,
1351 				     enum xgene_dma_ring_cfgsize cfgsize)
1352 {
1353 	int ret;
1354 
1355 	/* Setup DMA ring descriptor variables */
1356 	ring->pdma = chan->pdma;
1357 	ring->cfgsize = cfgsize;
1358 	ring->num = chan->pdma->ring_num++;
1359 	ring->id = XGENE_DMA_RING_ID_GET(ring->owner, ring->buf_num);
1360 
1361 	ret = xgene_dma_get_ring_size(chan, cfgsize);
1362 	if (ret <= 0)
1363 		return ret;
1364 	ring->size = ret;
1365 
1366 	/* Allocate memory for DMA ring descriptor */
1367 	ring->desc_vaddr = dma_zalloc_coherent(chan->dev, ring->size,
1368 					       &ring->desc_paddr, GFP_KERNEL);
1369 	if (!ring->desc_vaddr) {
1370 		chan_err(chan, "Failed to allocate ring desc\n");
1371 		return -ENOMEM;
1372 	}
1373 
1374 	/* Configure and enable DMA ring */
1375 	xgene_dma_set_ring_cmd(ring);
1376 	xgene_dma_setup_ring(ring);
1377 
1378 	return 0;
1379 }
1380 
1381 static int xgene_dma_create_chan_rings(struct xgene_dma_chan *chan)
1382 {
1383 	struct xgene_dma_ring *rx_ring = &chan->rx_ring;
1384 	struct xgene_dma_ring *tx_ring = &chan->tx_ring;
1385 	int ret;
1386 
1387 	/* Create DMA Rx ring descriptor */
1388 	rx_ring->owner = XGENE_DMA_RING_OWNER_CPU;
1389 	rx_ring->buf_num = XGENE_DMA_CPU_BUFNUM + chan->id;
1390 
1391 	ret = xgene_dma_create_ring_one(chan, rx_ring,
1392 					XGENE_DMA_RING_CFG_SIZE_64KB);
1393 	if (ret)
1394 		return ret;
1395 
1396 	chan_dbg(chan, "Rx ring id 0x%X num %d desc 0x%p\n",
1397 		 rx_ring->id, rx_ring->num, rx_ring->desc_vaddr);
1398 
1399 	/* Create DMA Tx ring descriptor */
1400 	tx_ring->owner = XGENE_DMA_RING_OWNER_DMA;
1401 	tx_ring->buf_num = XGENE_DMA_BUFNUM + chan->id;
1402 
1403 	ret = xgene_dma_create_ring_one(chan, tx_ring,
1404 					XGENE_DMA_RING_CFG_SIZE_64KB);
1405 	if (ret) {
1406 		xgene_dma_delete_ring_one(rx_ring);
1407 		return ret;
1408 	}
1409 
1410 	tx_ring->dst_ring_num = XGENE_DMA_RING_DST_ID(rx_ring->num);
1411 
1412 	chan_dbg(chan,
1413 		 "Tx ring id 0x%X num %d desc 0x%p\n",
1414 		 tx_ring->id, tx_ring->num, tx_ring->desc_vaddr);
1415 
1416 	/* Set the max outstanding request possible to this channel */
1417 	chan->max_outstanding = tx_ring->slots;
1418 
1419 	return ret;
1420 }
1421 
1422 static int xgene_dma_init_rings(struct xgene_dma *pdma)
1423 {
1424 	int ret, i, j;
1425 
1426 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1427 		ret = xgene_dma_create_chan_rings(&pdma->chan[i]);
1428 		if (ret) {
1429 			for (j = 0; j < i; j++)
1430 				xgene_dma_delete_chan_rings(&pdma->chan[j]);
1431 			return ret;
1432 		}
1433 	}
1434 
1435 	return ret;
1436 }
1437 
1438 static void xgene_dma_enable(struct xgene_dma *pdma)
1439 {
1440 	u32 val;
1441 
1442 	/* Configure and enable DMA engine */
1443 	val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
1444 	XGENE_DMA_CH_SETUP(val);
1445 	XGENE_DMA_ENABLE(val);
1446 	iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
1447 }
1448 
1449 static void xgene_dma_disable(struct xgene_dma *pdma)
1450 {
1451 	u32 val;
1452 
1453 	val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
1454 	XGENE_DMA_DISABLE(val);
1455 	iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
1456 }
1457 
1458 static void xgene_dma_mask_interrupts(struct xgene_dma *pdma)
1459 {
1460 	/*
1461 	 * Mask DMA ring overflow, underflow and
1462 	 * AXI write/read error interrupts
1463 	 */
1464 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1465 		  pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
1466 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1467 		  pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
1468 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1469 		  pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
1470 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1471 		  pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
1472 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1473 		  pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
1474 
1475 	/* Mask DMA error interrupts */
1476 	iowrite32(XGENE_DMA_INT_ALL_MASK, pdma->csr_dma + XGENE_DMA_INT_MASK);
1477 }
1478 
1479 static void xgene_dma_unmask_interrupts(struct xgene_dma *pdma)
1480 {
1481 	/*
1482 	 * Unmask DMA ring overflow, underflow and
1483 	 * AXI write/read error interrupts
1484 	 */
1485 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1486 		  pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
1487 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1488 		  pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
1489 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1490 		  pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
1491 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1492 		  pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
1493 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1494 		  pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
1495 
1496 	/* Unmask DMA error interrupts */
1497 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1498 		  pdma->csr_dma + XGENE_DMA_INT_MASK);
1499 }
1500 
1501 static void xgene_dma_init_hw(struct xgene_dma *pdma)
1502 {
1503 	u32 val;
1504 
1505 	/* Associate DMA ring to corresponding ring HW */
1506 	iowrite32(XGENE_DMA_ASSOC_RING_MNGR1,
1507 		  pdma->csr_dma + XGENE_DMA_CFG_RING_WQ_ASSOC);
1508 
1509 	/* Configure RAID6 polynomial control setting */
1510 	if (is_pq_enabled(pdma))
1511 		iowrite32(XGENE_DMA_RAID6_MULTI_CTRL(0x1D),
1512 			  pdma->csr_dma + XGENE_DMA_RAID6_CONT);
1513 	else
1514 		dev_info(pdma->dev, "PQ is disabled in HW\n");
1515 
1516 	xgene_dma_enable(pdma);
1517 	xgene_dma_unmask_interrupts(pdma);
1518 
1519 	/* Get DMA id and version info */
1520 	val = ioread32(pdma->csr_dma + XGENE_DMA_IPBRR);
1521 
1522 	/* DMA device info */
1523 	dev_info(pdma->dev,
1524 		 "X-Gene DMA v%d.%02d.%02d driver registered %d channels",
1525 		 XGENE_DMA_REV_NO_RD(val), XGENE_DMA_BUS_ID_RD(val),
1526 		 XGENE_DMA_DEV_ID_RD(val), XGENE_DMA_MAX_CHANNEL);
1527 }
1528 
1529 static int xgene_dma_init_ring_mngr(struct xgene_dma *pdma)
1530 {
1531 	if (ioread32(pdma->csr_ring + XGENE_DMA_RING_CLKEN) &&
1532 	    (!ioread32(pdma->csr_ring + XGENE_DMA_RING_SRST)))
1533 		return 0;
1534 
1535 	iowrite32(0x3, pdma->csr_ring + XGENE_DMA_RING_CLKEN);
1536 	iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_SRST);
1537 
1538 	/* Bring up memory */
1539 	iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
1540 
1541 	/* Force a barrier */
1542 	ioread32(pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
1543 
1544 	/* reset may take up to 1ms */
1545 	usleep_range(1000, 1100);
1546 
1547 	if (ioread32(pdma->csr_ring + XGENE_DMA_RING_BLK_MEM_RDY)
1548 		!= XGENE_DMA_RING_BLK_MEM_RDY_VAL) {
1549 		dev_err(pdma->dev,
1550 			"Failed to release ring mngr memory from shutdown\n");
1551 		return -ENODEV;
1552 	}
1553 
1554 	/* program threshold set 1 and all hysteresis */
1555 	iowrite32(XGENE_DMA_RING_THRESLD0_SET1_VAL,
1556 		  pdma->csr_ring + XGENE_DMA_RING_THRESLD0_SET1);
1557 	iowrite32(XGENE_DMA_RING_THRESLD1_SET1_VAL,
1558 		  pdma->csr_ring + XGENE_DMA_RING_THRESLD1_SET1);
1559 	iowrite32(XGENE_DMA_RING_HYSTERESIS_VAL,
1560 		  pdma->csr_ring + XGENE_DMA_RING_HYSTERESIS);
1561 
1562 	/* Enable QPcore and assign error queue */
1563 	iowrite32(XGENE_DMA_RING_ENABLE,
1564 		  pdma->csr_ring + XGENE_DMA_RING_CONFIG);
1565 
1566 	return 0;
1567 }
1568 
1569 static int xgene_dma_init_mem(struct xgene_dma *pdma)
1570 {
1571 	int ret;
1572 
1573 	ret = xgene_dma_init_ring_mngr(pdma);
1574 	if (ret)
1575 		return ret;
1576 
1577 	/* Bring up memory */
1578 	iowrite32(0x0, pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
1579 
1580 	/* Force a barrier */
1581 	ioread32(pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
1582 
1583 	/* reset may take up to 1ms */
1584 	usleep_range(1000, 1100);
1585 
1586 	if (ioread32(pdma->csr_dma + XGENE_DMA_BLK_MEM_RDY)
1587 		!= XGENE_DMA_BLK_MEM_RDY_VAL) {
1588 		dev_err(pdma->dev,
1589 			"Failed to release DMA memory from shutdown\n");
1590 		return -ENODEV;
1591 	}
1592 
1593 	return 0;
1594 }
1595 
1596 static int xgene_dma_request_irqs(struct xgene_dma *pdma)
1597 {
1598 	struct xgene_dma_chan *chan;
1599 	int ret, i, j;
1600 
1601 	/* Register DMA error irq */
1602 	ret = devm_request_irq(pdma->dev, pdma->err_irq, xgene_dma_err_isr,
1603 			       0, "dma_error", pdma);
1604 	if (ret) {
1605 		dev_err(pdma->dev,
1606 			"Failed to register error IRQ %d\n", pdma->err_irq);
1607 		return ret;
1608 	}
1609 
1610 	/* Register DMA channel rx irq */
1611 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1612 		chan = &pdma->chan[i];
1613 		irq_set_status_flags(chan->rx_irq, IRQ_DISABLE_UNLAZY);
1614 		ret = devm_request_irq(chan->dev, chan->rx_irq,
1615 				       xgene_dma_chan_ring_isr,
1616 				       0, chan->name, chan);
1617 		if (ret) {
1618 			chan_err(chan, "Failed to register Rx IRQ %d\n",
1619 				 chan->rx_irq);
1620 			devm_free_irq(pdma->dev, pdma->err_irq, pdma);
1621 
1622 			for (j = 0; j < i; j++) {
1623 				chan = &pdma->chan[i];
1624 				irq_clear_status_flags(chan->rx_irq, IRQ_DISABLE_UNLAZY);
1625 				devm_free_irq(chan->dev, chan->rx_irq, chan);
1626 			}
1627 
1628 			return ret;
1629 		}
1630 	}
1631 
1632 	return 0;
1633 }
1634 
1635 static void xgene_dma_free_irqs(struct xgene_dma *pdma)
1636 {
1637 	struct xgene_dma_chan *chan;
1638 	int i;
1639 
1640 	/* Free DMA device error irq */
1641 	devm_free_irq(pdma->dev, pdma->err_irq, pdma);
1642 
1643 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1644 		chan = &pdma->chan[i];
1645 		irq_clear_status_flags(chan->rx_irq, IRQ_DISABLE_UNLAZY);
1646 		devm_free_irq(chan->dev, chan->rx_irq, chan);
1647 	}
1648 }
1649 
1650 static void xgene_dma_set_caps(struct xgene_dma_chan *chan,
1651 			       struct dma_device *dma_dev)
1652 {
1653 	/* Initialize DMA device capability mask */
1654 	dma_cap_zero(dma_dev->cap_mask);
1655 
1656 	/* Set DMA device capability */
1657 	dma_cap_set(DMA_SG, dma_dev->cap_mask);
1658 
1659 	/* Basically here, the X-Gene SoC DMA engine channel 0 supports XOR
1660 	 * and channel 1 supports XOR, PQ both. First thing here is we have
1661 	 * mechanism in hw to enable/disable PQ/XOR supports on channel 1,
1662 	 * we can make sure this by reading SoC Efuse register.
1663 	 * Second thing, we have hw errata that if we run channel 0 and
1664 	 * channel 1 simultaneously with executing XOR and PQ request,
1665 	 * suddenly DMA engine hangs, So here we enable XOR on channel 0 only
1666 	 * if XOR and PQ supports on channel 1 is disabled.
1667 	 */
1668 	if ((chan->id == XGENE_DMA_PQ_CHANNEL) &&
1669 	    is_pq_enabled(chan->pdma)) {
1670 		dma_cap_set(DMA_PQ, dma_dev->cap_mask);
1671 		dma_cap_set(DMA_XOR, dma_dev->cap_mask);
1672 	} else if ((chan->id == XGENE_DMA_XOR_CHANNEL) &&
1673 		   !is_pq_enabled(chan->pdma)) {
1674 		dma_cap_set(DMA_XOR, dma_dev->cap_mask);
1675 	}
1676 
1677 	/* Set base and prep routines */
1678 	dma_dev->dev = chan->dev;
1679 	dma_dev->device_alloc_chan_resources = xgene_dma_alloc_chan_resources;
1680 	dma_dev->device_free_chan_resources = xgene_dma_free_chan_resources;
1681 	dma_dev->device_issue_pending = xgene_dma_issue_pending;
1682 	dma_dev->device_tx_status = xgene_dma_tx_status;
1683 	dma_dev->device_prep_dma_sg = xgene_dma_prep_sg;
1684 
1685 	if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
1686 		dma_dev->device_prep_dma_xor = xgene_dma_prep_xor;
1687 		dma_dev->max_xor = XGENE_DMA_MAX_XOR_SRC;
1688 		dma_dev->xor_align = DMAENGINE_ALIGN_64_BYTES;
1689 	}
1690 
1691 	if (dma_has_cap(DMA_PQ, dma_dev->cap_mask)) {
1692 		dma_dev->device_prep_dma_pq = xgene_dma_prep_pq;
1693 		dma_dev->max_pq = XGENE_DMA_MAX_XOR_SRC;
1694 		dma_dev->pq_align = DMAENGINE_ALIGN_64_BYTES;
1695 	}
1696 }
1697 
1698 static int xgene_dma_async_register(struct xgene_dma *pdma, int id)
1699 {
1700 	struct xgene_dma_chan *chan = &pdma->chan[id];
1701 	struct dma_device *dma_dev = &pdma->dma_dev[id];
1702 	int ret;
1703 
1704 	chan->dma_chan.device = dma_dev;
1705 
1706 	spin_lock_init(&chan->lock);
1707 	INIT_LIST_HEAD(&chan->ld_pending);
1708 	INIT_LIST_HEAD(&chan->ld_running);
1709 	INIT_LIST_HEAD(&chan->ld_completed);
1710 	tasklet_init(&chan->tasklet, xgene_dma_tasklet_cb,
1711 		     (unsigned long)chan);
1712 
1713 	chan->pending = 0;
1714 	chan->desc_pool = NULL;
1715 	dma_cookie_init(&chan->dma_chan);
1716 
1717 	/* Setup dma device capabilities and prep routines */
1718 	xgene_dma_set_caps(chan, dma_dev);
1719 
1720 	/* Initialize DMA device list head */
1721 	INIT_LIST_HEAD(&dma_dev->channels);
1722 	list_add_tail(&chan->dma_chan.device_node, &dma_dev->channels);
1723 
1724 	/* Register with Linux async DMA framework*/
1725 	ret = dma_async_device_register(dma_dev);
1726 	if (ret) {
1727 		chan_err(chan, "Failed to register async device %d", ret);
1728 		tasklet_kill(&chan->tasklet);
1729 
1730 		return ret;
1731 	}
1732 
1733 	/* DMA capability info */
1734 	dev_info(pdma->dev,
1735 		 "%s: CAPABILITY ( %s%s%s)\n", dma_chan_name(&chan->dma_chan),
1736 		 dma_has_cap(DMA_SG, dma_dev->cap_mask) ? "SGCPY " : "",
1737 		 dma_has_cap(DMA_XOR, dma_dev->cap_mask) ? "XOR " : "",
1738 		 dma_has_cap(DMA_PQ, dma_dev->cap_mask) ? "PQ " : "");
1739 
1740 	return 0;
1741 }
1742 
1743 static int xgene_dma_init_async(struct xgene_dma *pdma)
1744 {
1745 	int ret, i, j;
1746 
1747 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL ; i++) {
1748 		ret = xgene_dma_async_register(pdma, i);
1749 		if (ret) {
1750 			for (j = 0; j < i; j++) {
1751 				dma_async_device_unregister(&pdma->dma_dev[j]);
1752 				tasklet_kill(&pdma->chan[j].tasklet);
1753 			}
1754 
1755 			return ret;
1756 		}
1757 	}
1758 
1759 	return ret;
1760 }
1761 
1762 static void xgene_dma_async_unregister(struct xgene_dma *pdma)
1763 {
1764 	int i;
1765 
1766 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
1767 		dma_async_device_unregister(&pdma->dma_dev[i]);
1768 }
1769 
1770 static void xgene_dma_init_channels(struct xgene_dma *pdma)
1771 {
1772 	struct xgene_dma_chan *chan;
1773 	int i;
1774 
1775 	pdma->ring_num = XGENE_DMA_RING_NUM;
1776 
1777 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1778 		chan = &pdma->chan[i];
1779 		chan->dev = pdma->dev;
1780 		chan->pdma = pdma;
1781 		chan->id = i;
1782 		snprintf(chan->name, sizeof(chan->name), "dmachan%d", chan->id);
1783 	}
1784 }
1785 
1786 static int xgene_dma_get_resources(struct platform_device *pdev,
1787 				   struct xgene_dma *pdma)
1788 {
1789 	struct resource *res;
1790 	int irq, i;
1791 
1792 	/* Get DMA csr region */
1793 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1794 	if (!res) {
1795 		dev_err(&pdev->dev, "Failed to get csr region\n");
1796 		return -ENXIO;
1797 	}
1798 
1799 	pdma->csr_dma = devm_ioremap(&pdev->dev, res->start,
1800 				     resource_size(res));
1801 	if (!pdma->csr_dma) {
1802 		dev_err(&pdev->dev, "Failed to ioremap csr region");
1803 		return -ENOMEM;
1804 	}
1805 
1806 	/* Get DMA ring csr region */
1807 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1808 	if (!res) {
1809 		dev_err(&pdev->dev, "Failed to get ring csr region\n");
1810 		return -ENXIO;
1811 	}
1812 
1813 	pdma->csr_ring =  devm_ioremap(&pdev->dev, res->start,
1814 				       resource_size(res));
1815 	if (!pdma->csr_ring) {
1816 		dev_err(&pdev->dev, "Failed to ioremap ring csr region");
1817 		return -ENOMEM;
1818 	}
1819 
1820 	/* Get DMA ring cmd csr region */
1821 	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
1822 	if (!res) {
1823 		dev_err(&pdev->dev, "Failed to get ring cmd csr region\n");
1824 		return -ENXIO;
1825 	}
1826 
1827 	pdma->csr_ring_cmd = devm_ioremap(&pdev->dev, res->start,
1828 					  resource_size(res));
1829 	if (!pdma->csr_ring_cmd) {
1830 		dev_err(&pdev->dev, "Failed to ioremap ring cmd csr region");
1831 		return -ENOMEM;
1832 	}
1833 
1834 	pdma->csr_ring_cmd += XGENE_DMA_RING_CMD_SM_OFFSET;
1835 
1836 	/* Get efuse csr region */
1837 	res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
1838 	if (!res) {
1839 		dev_err(&pdev->dev, "Failed to get efuse csr region\n");
1840 		return -ENXIO;
1841 	}
1842 
1843 	pdma->csr_efuse = devm_ioremap(&pdev->dev, res->start,
1844 				       resource_size(res));
1845 	if (!pdma->csr_efuse) {
1846 		dev_err(&pdev->dev, "Failed to ioremap efuse csr region");
1847 		return -ENOMEM;
1848 	}
1849 
1850 	/* Get DMA error interrupt */
1851 	irq = platform_get_irq(pdev, 0);
1852 	if (irq <= 0) {
1853 		dev_err(&pdev->dev, "Failed to get Error IRQ\n");
1854 		return -ENXIO;
1855 	}
1856 
1857 	pdma->err_irq = irq;
1858 
1859 	/* Get DMA Rx ring descriptor interrupts for all DMA channels */
1860 	for (i = 1; i <= XGENE_DMA_MAX_CHANNEL; i++) {
1861 		irq = platform_get_irq(pdev, i);
1862 		if (irq <= 0) {
1863 			dev_err(&pdev->dev, "Failed to get Rx IRQ\n");
1864 			return -ENXIO;
1865 		}
1866 
1867 		pdma->chan[i - 1].rx_irq = irq;
1868 	}
1869 
1870 	return 0;
1871 }
1872 
1873 static int xgene_dma_probe(struct platform_device *pdev)
1874 {
1875 	struct xgene_dma *pdma;
1876 	int ret, i;
1877 
1878 	pdma = devm_kzalloc(&pdev->dev, sizeof(*pdma), GFP_KERNEL);
1879 	if (!pdma)
1880 		return -ENOMEM;
1881 
1882 	pdma->dev = &pdev->dev;
1883 	platform_set_drvdata(pdev, pdma);
1884 
1885 	ret = xgene_dma_get_resources(pdev, pdma);
1886 	if (ret)
1887 		return ret;
1888 
1889 	pdma->clk = devm_clk_get(&pdev->dev, NULL);
1890 	if (IS_ERR(pdma->clk) && !ACPI_COMPANION(&pdev->dev)) {
1891 		dev_err(&pdev->dev, "Failed to get clk\n");
1892 		return PTR_ERR(pdma->clk);
1893 	}
1894 
1895 	/* Enable clk before accessing registers */
1896 	if (!IS_ERR(pdma->clk)) {
1897 		ret = clk_prepare_enable(pdma->clk);
1898 		if (ret) {
1899 			dev_err(&pdev->dev, "Failed to enable clk %d\n", ret);
1900 			return ret;
1901 		}
1902 	}
1903 
1904 	/* Remove DMA RAM out of shutdown */
1905 	ret = xgene_dma_init_mem(pdma);
1906 	if (ret)
1907 		goto err_clk_enable;
1908 
1909 	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(42));
1910 	if (ret) {
1911 		dev_err(&pdev->dev, "No usable DMA configuration\n");
1912 		goto err_dma_mask;
1913 	}
1914 
1915 	/* Initialize DMA channels software state */
1916 	xgene_dma_init_channels(pdma);
1917 
1918 	/* Configue DMA rings */
1919 	ret = xgene_dma_init_rings(pdma);
1920 	if (ret)
1921 		goto err_clk_enable;
1922 
1923 	ret = xgene_dma_request_irqs(pdma);
1924 	if (ret)
1925 		goto err_request_irq;
1926 
1927 	/* Configure and enable DMA engine */
1928 	xgene_dma_init_hw(pdma);
1929 
1930 	/* Register DMA device with linux async framework */
1931 	ret = xgene_dma_init_async(pdma);
1932 	if (ret)
1933 		goto err_async_init;
1934 
1935 	return 0;
1936 
1937 err_async_init:
1938 	xgene_dma_free_irqs(pdma);
1939 
1940 err_request_irq:
1941 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
1942 		xgene_dma_delete_chan_rings(&pdma->chan[i]);
1943 
1944 err_dma_mask:
1945 err_clk_enable:
1946 	if (!IS_ERR(pdma->clk))
1947 		clk_disable_unprepare(pdma->clk);
1948 
1949 	return ret;
1950 }
1951 
1952 static int xgene_dma_remove(struct platform_device *pdev)
1953 {
1954 	struct xgene_dma *pdma = platform_get_drvdata(pdev);
1955 	struct xgene_dma_chan *chan;
1956 	int i;
1957 
1958 	xgene_dma_async_unregister(pdma);
1959 
1960 	/* Mask interrupts and disable DMA engine */
1961 	xgene_dma_mask_interrupts(pdma);
1962 	xgene_dma_disable(pdma);
1963 	xgene_dma_free_irqs(pdma);
1964 
1965 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1966 		chan = &pdma->chan[i];
1967 		tasklet_kill(&chan->tasklet);
1968 		xgene_dma_delete_chan_rings(chan);
1969 	}
1970 
1971 	if (!IS_ERR(pdma->clk))
1972 		clk_disable_unprepare(pdma->clk);
1973 
1974 	return 0;
1975 }
1976 
1977 #ifdef CONFIG_ACPI
1978 static const struct acpi_device_id xgene_dma_acpi_match_ptr[] = {
1979 	{"APMC0D43", 0},
1980 	{},
1981 };
1982 MODULE_DEVICE_TABLE(acpi, xgene_dma_acpi_match_ptr);
1983 #endif
1984 
1985 static const struct of_device_id xgene_dma_of_match_ptr[] = {
1986 	{.compatible = "apm,xgene-storm-dma",},
1987 	{},
1988 };
1989 MODULE_DEVICE_TABLE(of, xgene_dma_of_match_ptr);
1990 
1991 static struct platform_driver xgene_dma_driver = {
1992 	.probe = xgene_dma_probe,
1993 	.remove = xgene_dma_remove,
1994 	.driver = {
1995 		.name = "X-Gene-DMA",
1996 		.of_match_table = xgene_dma_of_match_ptr,
1997 		.acpi_match_table = ACPI_PTR(xgene_dma_acpi_match_ptr),
1998 	},
1999 };
2000 
2001 module_platform_driver(xgene_dma_driver);
2002 
2003 MODULE_DESCRIPTION("APM X-Gene SoC DMA driver");
2004 MODULE_AUTHOR("Rameshwar Prasad Sahu <rsahu@apm.com>");
2005 MODULE_AUTHOR("Loc Ho <lho@apm.com>");
2006 MODULE_LICENSE("GPL");
2007 MODULE_VERSION("1.0");
2008