xref: /linux/drivers/dma/xgene-dma.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Applied Micro X-Gene SoC DMA engine Driver
4  *
5  * Copyright (c) 2015, Applied Micro Circuits Corporation
6  * Authors: Rameshwar Prasad Sahu <rsahu@apm.com>
7  *	    Loc Ho <lho@apm.com>
8  *
9  * NOTE: PM support is currently not available.
10  */
11 
12 #include <linux/acpi.h>
13 #include <linux/clk.h>
14 #include <linux/delay.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/dmaengine.h>
17 #include <linux/dmapool.h>
18 #include <linux/interrupt.h>
19 #include <linux/io.h>
20 #include <linux/irq.h>
21 #include <linux/mod_devicetable.h>
22 #include <linux/module.h>
23 #include <linux/platform_device.h>
24 
25 #include "dmaengine.h"
26 
27 /* X-Gene DMA ring csr registers and bit definations */
28 #define XGENE_DMA_RING_CONFIG			0x04
29 #define XGENE_DMA_RING_ENABLE			BIT(31)
30 #define XGENE_DMA_RING_ID			0x08
31 #define XGENE_DMA_RING_ID_SETUP(v)		((v) | BIT(31))
32 #define XGENE_DMA_RING_ID_BUF			0x0C
33 #define XGENE_DMA_RING_ID_BUF_SETUP(v)		(((v) << 9) | BIT(21))
34 #define XGENE_DMA_RING_THRESLD0_SET1		0x30
35 #define XGENE_DMA_RING_THRESLD0_SET1_VAL	0X64
36 #define XGENE_DMA_RING_THRESLD1_SET1		0x34
37 #define XGENE_DMA_RING_THRESLD1_SET1_VAL	0xC8
38 #define XGENE_DMA_RING_HYSTERESIS		0x68
39 #define XGENE_DMA_RING_HYSTERESIS_VAL		0xFFFFFFFF
40 #define XGENE_DMA_RING_STATE			0x6C
41 #define XGENE_DMA_RING_STATE_WR_BASE		0x70
42 #define XGENE_DMA_RING_NE_INT_MODE		0x017C
43 #define XGENE_DMA_RING_NE_INT_MODE_SET(m, v)	\
44 	((m) = ((m) & ~BIT(31 - (v))) | BIT(31 - (v)))
45 #define XGENE_DMA_RING_NE_INT_MODE_RESET(m, v)	\
46 	((m) &= (~BIT(31 - (v))))
47 #define XGENE_DMA_RING_CLKEN			0xC208
48 #define XGENE_DMA_RING_SRST			0xC200
49 #define XGENE_DMA_RING_MEM_RAM_SHUTDOWN		0xD070
50 #define XGENE_DMA_RING_BLK_MEM_RDY		0xD074
51 #define XGENE_DMA_RING_BLK_MEM_RDY_VAL		0xFFFFFFFF
52 #define XGENE_DMA_RING_ID_GET(owner, num)	(((owner) << 6) | (num))
53 #define XGENE_DMA_RING_DST_ID(v)		((1 << 10) | (v))
54 #define XGENE_DMA_RING_CMD_OFFSET		0x2C
55 #define XGENE_DMA_RING_CMD_BASE_OFFSET(v)	((v) << 6)
56 #define XGENE_DMA_RING_COHERENT_SET(m)		\
57 	(((u32 *)(m))[2] |= BIT(4))
58 #define XGENE_DMA_RING_ADDRL_SET(m, v)		\
59 	(((u32 *)(m))[2] |= (((v) >> 8) << 5))
60 #define XGENE_DMA_RING_ADDRH_SET(m, v)		\
61 	(((u32 *)(m))[3] |= ((v) >> 35))
62 #define XGENE_DMA_RING_ACCEPTLERR_SET(m)	\
63 	(((u32 *)(m))[3] |= BIT(19))
64 #define XGENE_DMA_RING_SIZE_SET(m, v)		\
65 	(((u32 *)(m))[3] |= ((v) << 23))
66 #define XGENE_DMA_RING_RECOMBBUF_SET(m)		\
67 	(((u32 *)(m))[3] |= BIT(27))
68 #define XGENE_DMA_RING_RECOMTIMEOUTL_SET(m)	\
69 	(((u32 *)(m))[3] |= (0x7 << 28))
70 #define XGENE_DMA_RING_RECOMTIMEOUTH_SET(m)	\
71 	(((u32 *)(m))[4] |= 0x3)
72 #define XGENE_DMA_RING_SELTHRSH_SET(m)		\
73 	(((u32 *)(m))[4] |= BIT(3))
74 #define XGENE_DMA_RING_TYPE_SET(m, v)		\
75 	(((u32 *)(m))[4] |= ((v) << 19))
76 
77 /* X-Gene DMA device csr registers and bit definitions */
78 #define XGENE_DMA_IPBRR				0x0
79 #define XGENE_DMA_DEV_ID_RD(v)			((v) & 0x00000FFF)
80 #define XGENE_DMA_BUS_ID_RD(v)			(((v) >> 12) & 3)
81 #define XGENE_DMA_REV_NO_RD(v)			(((v) >> 14) & 3)
82 #define XGENE_DMA_GCR				0x10
83 #define XGENE_DMA_CH_SETUP(v)			\
84 	((v) = ((v) & ~0x000FFFFF) | 0x000AAFFF)
85 #define XGENE_DMA_ENABLE(v)			((v) |= BIT(31))
86 #define XGENE_DMA_DISABLE(v)			((v) &= ~BIT(31))
87 #define XGENE_DMA_RAID6_CONT			0x14
88 #define XGENE_DMA_RAID6_MULTI_CTRL(v)		((v) << 24)
89 #define XGENE_DMA_INT				0x70
90 #define XGENE_DMA_INT_MASK			0x74
91 #define XGENE_DMA_INT_ALL_MASK			0xFFFFFFFF
92 #define XGENE_DMA_INT_ALL_UNMASK		0x0
93 #define XGENE_DMA_INT_MASK_SHIFT		0x14
94 #define XGENE_DMA_RING_INT0_MASK		0x90A0
95 #define XGENE_DMA_RING_INT1_MASK		0x90A8
96 #define XGENE_DMA_RING_INT2_MASK		0x90B0
97 #define XGENE_DMA_RING_INT3_MASK		0x90B8
98 #define XGENE_DMA_RING_INT4_MASK		0x90C0
99 #define XGENE_DMA_CFG_RING_WQ_ASSOC		0x90E0
100 #define XGENE_DMA_ASSOC_RING_MNGR1		0xFFFFFFFF
101 #define XGENE_DMA_MEM_RAM_SHUTDOWN		0xD070
102 #define XGENE_DMA_BLK_MEM_RDY			0xD074
103 #define XGENE_DMA_BLK_MEM_RDY_VAL		0xFFFFFFFF
104 #define XGENE_DMA_RING_CMD_SM_OFFSET		0x8000
105 
106 /* X-Gene SoC EFUSE csr register and bit defination */
107 #define XGENE_SOC_JTAG1_SHADOW			0x18
108 #define XGENE_DMA_PQ_DISABLE_MASK		BIT(13)
109 
110 /* X-Gene DMA Descriptor format */
111 #define XGENE_DMA_DESC_NV_BIT			BIT_ULL(50)
112 #define XGENE_DMA_DESC_IN_BIT			BIT_ULL(55)
113 #define XGENE_DMA_DESC_C_BIT			BIT_ULL(63)
114 #define XGENE_DMA_DESC_DR_BIT			BIT_ULL(61)
115 #define XGENE_DMA_DESC_ELERR_POS		46
116 #define XGENE_DMA_DESC_RTYPE_POS		56
117 #define XGENE_DMA_DESC_LERR_POS			60
118 #define XGENE_DMA_DESC_BUFLEN_POS		48
119 #define XGENE_DMA_DESC_HOENQ_NUM_POS		48
120 #define XGENE_DMA_DESC_ELERR_RD(m)		\
121 	(((m) >> XGENE_DMA_DESC_ELERR_POS) & 0x3)
122 #define XGENE_DMA_DESC_LERR_RD(m)		\
123 	(((m) >> XGENE_DMA_DESC_LERR_POS) & 0x7)
124 #define XGENE_DMA_DESC_STATUS(elerr, lerr)	\
125 	(((elerr) << 4) | (lerr))
126 
127 /* X-Gene DMA descriptor empty s/w signature */
128 #define XGENE_DMA_DESC_EMPTY_SIGNATURE		~0ULL
129 
130 /* X-Gene DMA configurable parameters defines */
131 #define XGENE_DMA_RING_NUM		512
132 #define XGENE_DMA_BUFNUM		0x0
133 #define XGENE_DMA_CPU_BUFNUM		0x18
134 #define XGENE_DMA_RING_OWNER_DMA	0x03
135 #define XGENE_DMA_RING_OWNER_CPU	0x0F
136 #define XGENE_DMA_RING_TYPE_REGULAR	0x01
137 #define XGENE_DMA_RING_WQ_DESC_SIZE	32	/* 32 Bytes */
138 #define XGENE_DMA_RING_NUM_CONFIG	5
139 #define XGENE_DMA_MAX_CHANNEL		4
140 #define XGENE_DMA_XOR_CHANNEL		0
141 #define XGENE_DMA_PQ_CHANNEL		1
142 #define XGENE_DMA_MAX_BYTE_CNT		0x4000	/* 16 KB */
143 #define XGENE_DMA_MAX_64B_DESC_BYTE_CNT	0x14000	/* 80 KB */
144 #define XGENE_DMA_MAX_XOR_SRC		5
145 #define XGENE_DMA_16K_BUFFER_LEN_CODE	0x0
146 #define XGENE_DMA_INVALID_LEN_CODE	0x7800000000000000ULL
147 
148 /* X-Gene DMA descriptor error codes */
149 #define ERR_DESC_AXI			0x01
150 #define ERR_BAD_DESC			0x02
151 #define ERR_READ_DATA_AXI		0x03
152 #define ERR_WRITE_DATA_AXI		0x04
153 #define ERR_FBP_TIMEOUT			0x05
154 #define ERR_ECC				0x06
155 #define ERR_DIFF_SIZE			0x08
156 #define ERR_SCT_GAT_LEN			0x09
157 #define ERR_CRC_ERR			0x11
158 #define ERR_CHKSUM			0x12
159 #define ERR_DIF				0x13
160 
161 /* X-Gene DMA error interrupt codes */
162 #define ERR_DIF_SIZE_INT		0x0
163 #define ERR_GS_ERR_INT			0x1
164 #define ERR_FPB_TIMEO_INT		0x2
165 #define ERR_WFIFO_OVF_INT		0x3
166 #define ERR_RFIFO_OVF_INT		0x4
167 #define ERR_WR_TIMEO_INT		0x5
168 #define ERR_RD_TIMEO_INT		0x6
169 #define ERR_WR_ERR_INT			0x7
170 #define ERR_RD_ERR_INT			0x8
171 #define ERR_BAD_DESC_INT		0x9
172 #define ERR_DESC_DST_INT		0xA
173 #define ERR_DESC_SRC_INT		0xB
174 
175 /* X-Gene DMA flyby operation code */
176 #define FLYBY_2SRC_XOR			0x80
177 #define FLYBY_3SRC_XOR			0x90
178 #define FLYBY_4SRC_XOR			0xA0
179 #define FLYBY_5SRC_XOR			0xB0
180 
181 /* X-Gene DMA SW descriptor flags */
182 #define XGENE_DMA_FLAG_64B_DESC		BIT(0)
183 
184 /* Define to dump X-Gene DMA descriptor */
185 #define XGENE_DMA_DESC_DUMP(desc, m)	\
186 	print_hex_dump(KERN_ERR, (m),	\
187 			DUMP_PREFIX_ADDRESS, 16, 8, (desc), 32, 0)
188 
189 #define to_dma_desc_sw(tx)		\
190 	container_of(tx, struct xgene_dma_desc_sw, tx)
191 #define to_dma_chan(dchan)		\
192 	container_of(dchan, struct xgene_dma_chan, dma_chan)
193 
194 #define chan_dbg(chan, fmt, arg...)	\
195 	dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
196 #define chan_err(chan, fmt, arg...)	\
197 	dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
198 
199 struct xgene_dma_desc_hw {
200 	__le64 m0;
201 	__le64 m1;
202 	__le64 m2;
203 	__le64 m3;
204 };
205 
206 enum xgene_dma_ring_cfgsize {
207 	XGENE_DMA_RING_CFG_SIZE_512B,
208 	XGENE_DMA_RING_CFG_SIZE_2KB,
209 	XGENE_DMA_RING_CFG_SIZE_16KB,
210 	XGENE_DMA_RING_CFG_SIZE_64KB,
211 	XGENE_DMA_RING_CFG_SIZE_512KB,
212 	XGENE_DMA_RING_CFG_SIZE_INVALID
213 };
214 
215 struct xgene_dma_ring {
216 	struct xgene_dma *pdma;
217 	u8 buf_num;
218 	u16 id;
219 	u16 num;
220 	u16 head;
221 	u16 owner;
222 	u16 slots;
223 	u16 dst_ring_num;
224 	u32 size;
225 	void __iomem *cmd;
226 	void __iomem *cmd_base;
227 	dma_addr_t desc_paddr;
228 	u32 state[XGENE_DMA_RING_NUM_CONFIG];
229 	enum xgene_dma_ring_cfgsize cfgsize;
230 	union {
231 		void *desc_vaddr;
232 		struct xgene_dma_desc_hw *desc_hw;
233 	};
234 };
235 
236 struct xgene_dma_desc_sw {
237 	struct xgene_dma_desc_hw desc1;
238 	struct xgene_dma_desc_hw desc2;
239 	u32 flags;
240 	struct list_head node;
241 	struct list_head tx_list;
242 	struct dma_async_tx_descriptor tx;
243 };
244 
245 /**
246  * struct xgene_dma_chan - internal representation of an X-Gene DMA channel
247  * @dma_chan: dmaengine channel object member
248  * @pdma: X-Gene DMA device structure reference
249  * @dev: struct device reference for dma mapping api
250  * @id: raw id of this channel
251  * @rx_irq: channel IRQ
252  * @name: name of X-Gene DMA channel
253  * @lock: serializes enqueue/dequeue operations to the descriptor pool
254  * @pending: number of transaction request pushed to DMA controller for
255  *	execution, but still waiting for completion,
256  * @max_outstanding: max number of outstanding request we can push to channel
257  * @ld_pending: descriptors which are queued to run, but have not yet been
258  *	submitted to the hardware for execution
259  * @ld_running: descriptors which are currently being executing by the hardware
260  * @ld_completed: descriptors which have finished execution by the hardware.
261  *	These descriptors have already had their cleanup actions run. They
262  *	are waiting for the ACK bit to be set by the async tx API.
263  * @desc_pool: descriptor pool for DMA operations
264  * @tasklet: bottom half where all completed descriptors cleans
265  * @tx_ring: transmit ring descriptor that we use to prepare actual
266  *	descriptors for further executions
267  * @rx_ring: receive ring descriptor that we use to get completed DMA
268  *	descriptors during cleanup time
269  */
270 struct xgene_dma_chan {
271 	struct dma_chan dma_chan;
272 	struct xgene_dma *pdma;
273 	struct device *dev;
274 	int id;
275 	int rx_irq;
276 	char name[10];
277 	spinlock_t lock;
278 	int pending;
279 	int max_outstanding;
280 	struct list_head ld_pending;
281 	struct list_head ld_running;
282 	struct list_head ld_completed;
283 	struct dma_pool *desc_pool;
284 	struct tasklet_struct tasklet;
285 	struct xgene_dma_ring tx_ring;
286 	struct xgene_dma_ring rx_ring;
287 };
288 
289 /**
290  * struct xgene_dma - internal representation of an X-Gene DMA device
291  * @dev: reference to this device's struct device
292  * @clk: reference to this device's clock
293  * @err_irq: DMA error irq number
294  * @ring_num: start id number for DMA ring
295  * @csr_dma: base for DMA register access
296  * @csr_ring: base for DMA ring register access
297  * @csr_ring_cmd: base for DMA ring command register access
298  * @csr_efuse: base for efuse register access
299  * @dma_dev: embedded struct dma_device
300  * @chan: reference to X-Gene DMA channels
301  */
302 struct xgene_dma {
303 	struct device *dev;
304 	struct clk *clk;
305 	int err_irq;
306 	int ring_num;
307 	void __iomem *csr_dma;
308 	void __iomem *csr_ring;
309 	void __iomem *csr_ring_cmd;
310 	void __iomem *csr_efuse;
311 	struct dma_device dma_dev[XGENE_DMA_MAX_CHANNEL];
312 	struct xgene_dma_chan chan[XGENE_DMA_MAX_CHANNEL];
313 };
314 
315 static const char * const xgene_dma_desc_err[] = {
316 	[ERR_DESC_AXI] = "AXI error when reading src/dst link list",
317 	[ERR_BAD_DESC] = "ERR or El_ERR fields not set to zero in desc",
318 	[ERR_READ_DATA_AXI] = "AXI error when reading data",
319 	[ERR_WRITE_DATA_AXI] = "AXI error when writing data",
320 	[ERR_FBP_TIMEOUT] = "Timeout on bufpool fetch",
321 	[ERR_ECC] = "ECC double bit error",
322 	[ERR_DIFF_SIZE] = "Bufpool too small to hold all the DIF result",
323 	[ERR_SCT_GAT_LEN] = "Gather and scatter data length not same",
324 	[ERR_CRC_ERR] = "CRC error",
325 	[ERR_CHKSUM] = "Checksum error",
326 	[ERR_DIF] = "DIF error",
327 };
328 
329 static const char * const xgene_dma_err[] = {
330 	[ERR_DIF_SIZE_INT] = "DIF size error",
331 	[ERR_GS_ERR_INT] = "Gather scatter not same size error",
332 	[ERR_FPB_TIMEO_INT] = "Free pool time out error",
333 	[ERR_WFIFO_OVF_INT] = "Write FIFO over flow error",
334 	[ERR_RFIFO_OVF_INT] = "Read FIFO over flow error",
335 	[ERR_WR_TIMEO_INT] = "Write time out error",
336 	[ERR_RD_TIMEO_INT] = "Read time out error",
337 	[ERR_WR_ERR_INT] = "HBF bus write error",
338 	[ERR_RD_ERR_INT] = "HBF bus read error",
339 	[ERR_BAD_DESC_INT] = "Ring descriptor HE0 not set error",
340 	[ERR_DESC_DST_INT] = "HFB reading dst link address error",
341 	[ERR_DESC_SRC_INT] = "HFB reading src link address error",
342 };
343 
344 static bool is_pq_enabled(struct xgene_dma *pdma)
345 {
346 	u32 val;
347 
348 	val = ioread32(pdma->csr_efuse + XGENE_SOC_JTAG1_SHADOW);
349 	return !(val & XGENE_DMA_PQ_DISABLE_MASK);
350 }
351 
352 static u64 xgene_dma_encode_len(size_t len)
353 {
354 	return (len < XGENE_DMA_MAX_BYTE_CNT) ?
355 		((u64)len << XGENE_DMA_DESC_BUFLEN_POS) :
356 		XGENE_DMA_16K_BUFFER_LEN_CODE;
357 }
358 
359 static u8 xgene_dma_encode_xor_flyby(u32 src_cnt)
360 {
361 	static u8 flyby_type[] = {
362 		FLYBY_2SRC_XOR, /* Dummy */
363 		FLYBY_2SRC_XOR, /* Dummy */
364 		FLYBY_2SRC_XOR,
365 		FLYBY_3SRC_XOR,
366 		FLYBY_4SRC_XOR,
367 		FLYBY_5SRC_XOR
368 	};
369 
370 	return flyby_type[src_cnt];
371 }
372 
373 static void xgene_dma_set_src_buffer(__le64 *ext8, size_t *len,
374 				     dma_addr_t *paddr)
375 {
376 	size_t nbytes = (*len < XGENE_DMA_MAX_BYTE_CNT) ?
377 			*len : XGENE_DMA_MAX_BYTE_CNT;
378 
379 	*ext8 |= cpu_to_le64(*paddr);
380 	*ext8 |= cpu_to_le64(xgene_dma_encode_len(nbytes));
381 	*len -= nbytes;
382 	*paddr += nbytes;
383 }
384 
385 static __le64 *xgene_dma_lookup_ext8(struct xgene_dma_desc_hw *desc, int idx)
386 {
387 	switch (idx) {
388 	case 0:
389 		return &desc->m1;
390 	case 1:
391 		return &desc->m0;
392 	case 2:
393 		return &desc->m3;
394 	case 3:
395 		return &desc->m2;
396 	default:
397 		pr_err("Invalid dma descriptor index\n");
398 	}
399 
400 	return NULL;
401 }
402 
403 static void xgene_dma_init_desc(struct xgene_dma_desc_hw *desc,
404 				u16 dst_ring_num)
405 {
406 	desc->m0 |= cpu_to_le64(XGENE_DMA_DESC_IN_BIT);
407 	desc->m0 |= cpu_to_le64((u64)XGENE_DMA_RING_OWNER_DMA <<
408 				XGENE_DMA_DESC_RTYPE_POS);
409 	desc->m1 |= cpu_to_le64(XGENE_DMA_DESC_C_BIT);
410 	desc->m3 |= cpu_to_le64((u64)dst_ring_num <<
411 				XGENE_DMA_DESC_HOENQ_NUM_POS);
412 }
413 
414 static void xgene_dma_prep_xor_desc(struct xgene_dma_chan *chan,
415 				    struct xgene_dma_desc_sw *desc_sw,
416 				    dma_addr_t *dst, dma_addr_t *src,
417 				    u32 src_cnt, size_t *nbytes,
418 				    const u8 *scf)
419 {
420 	struct xgene_dma_desc_hw *desc1, *desc2;
421 	size_t len = *nbytes;
422 	int i;
423 
424 	desc1 = &desc_sw->desc1;
425 	desc2 = &desc_sw->desc2;
426 
427 	/* Initialize DMA descriptor */
428 	xgene_dma_init_desc(desc1, chan->tx_ring.dst_ring_num);
429 
430 	/* Set destination address */
431 	desc1->m2 |= cpu_to_le64(XGENE_DMA_DESC_DR_BIT);
432 	desc1->m3 |= cpu_to_le64(*dst);
433 
434 	/* We have multiple source addresses, so need to set NV bit*/
435 	desc1->m0 |= cpu_to_le64(XGENE_DMA_DESC_NV_BIT);
436 
437 	/* Set flyby opcode */
438 	desc1->m2 |= cpu_to_le64(xgene_dma_encode_xor_flyby(src_cnt));
439 
440 	/* Set 1st to 5th source addresses */
441 	for (i = 0; i < src_cnt; i++) {
442 		len = *nbytes;
443 		xgene_dma_set_src_buffer((i == 0) ? &desc1->m1 :
444 					 xgene_dma_lookup_ext8(desc2, i - 1),
445 					 &len, &src[i]);
446 		desc1->m2 |= cpu_to_le64((scf[i] << ((i + 1) * 8)));
447 	}
448 
449 	/* Update meta data */
450 	*nbytes = len;
451 	*dst += XGENE_DMA_MAX_BYTE_CNT;
452 
453 	/* We need always 64B descriptor to perform xor or pq operations */
454 	desc_sw->flags |= XGENE_DMA_FLAG_64B_DESC;
455 }
456 
457 static dma_cookie_t xgene_dma_tx_submit(struct dma_async_tx_descriptor *tx)
458 {
459 	struct xgene_dma_desc_sw *desc;
460 	struct xgene_dma_chan *chan;
461 	dma_cookie_t cookie;
462 
463 	if (unlikely(!tx))
464 		return -EINVAL;
465 
466 	chan = to_dma_chan(tx->chan);
467 	desc = to_dma_desc_sw(tx);
468 
469 	spin_lock_bh(&chan->lock);
470 
471 	cookie = dma_cookie_assign(tx);
472 
473 	/* Add this transaction list onto the tail of the pending queue */
474 	list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
475 
476 	spin_unlock_bh(&chan->lock);
477 
478 	return cookie;
479 }
480 
481 static void xgene_dma_clean_descriptor(struct xgene_dma_chan *chan,
482 				       struct xgene_dma_desc_sw *desc)
483 {
484 	list_del(&desc->node);
485 	chan_dbg(chan, "LD %p free\n", desc);
486 	dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
487 }
488 
489 static struct xgene_dma_desc_sw *xgene_dma_alloc_descriptor(
490 				 struct xgene_dma_chan *chan)
491 {
492 	struct xgene_dma_desc_sw *desc;
493 	dma_addr_t phys;
494 
495 	desc = dma_pool_zalloc(chan->desc_pool, GFP_NOWAIT, &phys);
496 	if (!desc) {
497 		chan_err(chan, "Failed to allocate LDs\n");
498 		return NULL;
499 	}
500 
501 	INIT_LIST_HEAD(&desc->tx_list);
502 	desc->tx.phys = phys;
503 	desc->tx.tx_submit = xgene_dma_tx_submit;
504 	dma_async_tx_descriptor_init(&desc->tx, &chan->dma_chan);
505 
506 	chan_dbg(chan, "LD %p allocated\n", desc);
507 
508 	return desc;
509 }
510 
511 /**
512  * xgene_dma_clean_completed_descriptor - free all descriptors which
513  * has been completed and acked
514  * @chan: X-Gene DMA channel
515  *
516  * This function is used on all completed and acked descriptors.
517  */
518 static void xgene_dma_clean_completed_descriptor(struct xgene_dma_chan *chan)
519 {
520 	struct xgene_dma_desc_sw *desc, *_desc;
521 
522 	/* Run the callback for each descriptor, in order */
523 	list_for_each_entry_safe(desc, _desc, &chan->ld_completed, node) {
524 		if (async_tx_test_ack(&desc->tx))
525 			xgene_dma_clean_descriptor(chan, desc);
526 	}
527 }
528 
529 /**
530  * xgene_dma_run_tx_complete_actions - cleanup a single link descriptor
531  * @chan: X-Gene DMA channel
532  * @desc: descriptor to cleanup and free
533  *
534  * This function is used on a descriptor which has been executed by the DMA
535  * controller. It will run any callbacks, submit any dependencies.
536  */
537 static void xgene_dma_run_tx_complete_actions(struct xgene_dma_chan *chan,
538 					      struct xgene_dma_desc_sw *desc)
539 {
540 	struct dma_async_tx_descriptor *tx = &desc->tx;
541 
542 	/*
543 	 * If this is not the last transaction in the group,
544 	 * then no need to complete cookie and run any callback as
545 	 * this is not the tx_descriptor which had been sent to caller
546 	 * of this DMA request
547 	 */
548 
549 	if (tx->cookie == 0)
550 		return;
551 
552 	dma_cookie_complete(tx);
553 	dma_descriptor_unmap(tx);
554 
555 	/* Run the link descriptor callback function */
556 	dmaengine_desc_get_callback_invoke(tx, NULL);
557 
558 	/* Run any dependencies */
559 	dma_run_dependencies(tx);
560 }
561 
562 /**
563  * xgene_dma_clean_running_descriptor - move the completed descriptor from
564  * ld_running to ld_completed
565  * @chan: X-Gene DMA channel
566  * @desc: the descriptor which is completed
567  *
568  * Free the descriptor directly if acked by async_tx api,
569  * else move it to queue ld_completed.
570  */
571 static void xgene_dma_clean_running_descriptor(struct xgene_dma_chan *chan,
572 					       struct xgene_dma_desc_sw *desc)
573 {
574 	/* Remove from the list of running transactions */
575 	list_del(&desc->node);
576 
577 	/*
578 	 * the client is allowed to attach dependent operations
579 	 * until 'ack' is set
580 	 */
581 	if (!async_tx_test_ack(&desc->tx)) {
582 		/*
583 		 * Move this descriptor to the list of descriptors which is
584 		 * completed, but still awaiting the 'ack' bit to be set.
585 		 */
586 		list_add_tail(&desc->node, &chan->ld_completed);
587 		return;
588 	}
589 
590 	chan_dbg(chan, "LD %p free\n", desc);
591 	dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
592 }
593 
594 static void xgene_chan_xfer_request(struct xgene_dma_chan *chan,
595 				    struct xgene_dma_desc_sw *desc_sw)
596 {
597 	struct xgene_dma_ring *ring = &chan->tx_ring;
598 	struct xgene_dma_desc_hw *desc_hw;
599 
600 	/* Get hw descriptor from DMA tx ring */
601 	desc_hw = &ring->desc_hw[ring->head];
602 
603 	/*
604 	 * Increment the head count to point next
605 	 * descriptor for next time
606 	 */
607 	if (++ring->head == ring->slots)
608 		ring->head = 0;
609 
610 	/* Copy prepared sw descriptor data to hw descriptor */
611 	memcpy(desc_hw, &desc_sw->desc1, sizeof(*desc_hw));
612 
613 	/*
614 	 * Check if we have prepared 64B descriptor,
615 	 * in this case we need one more hw descriptor
616 	 */
617 	if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) {
618 		desc_hw = &ring->desc_hw[ring->head];
619 
620 		if (++ring->head == ring->slots)
621 			ring->head = 0;
622 
623 		memcpy(desc_hw, &desc_sw->desc2, sizeof(*desc_hw));
624 	}
625 
626 	/* Increment the pending transaction count */
627 	chan->pending += ((desc_sw->flags &
628 			  XGENE_DMA_FLAG_64B_DESC) ? 2 : 1);
629 
630 	/* Notify the hw that we have descriptor ready for execution */
631 	iowrite32((desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) ?
632 		  2 : 1, ring->cmd);
633 }
634 
635 /**
636  * xgene_chan_xfer_ld_pending - push any pending transactions to hw
637  * @chan : X-Gene DMA channel
638  *
639  * LOCKING: must hold chan->lock
640  */
641 static void xgene_chan_xfer_ld_pending(struct xgene_dma_chan *chan)
642 {
643 	struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
644 
645 	/*
646 	 * If the list of pending descriptors is empty, then we
647 	 * don't need to do any work at all
648 	 */
649 	if (list_empty(&chan->ld_pending)) {
650 		chan_dbg(chan, "No pending LDs\n");
651 		return;
652 	}
653 
654 	/*
655 	 * Move elements from the queue of pending transactions onto the list
656 	 * of running transactions and push it to hw for further executions
657 	 */
658 	list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_pending, node) {
659 		/*
660 		 * Check if have pushed max number of transactions to hw
661 		 * as capable, so let's stop here and will push remaining
662 		 * elements from pening ld queue after completing some
663 		 * descriptors that we have already pushed
664 		 */
665 		if (chan->pending >= chan->max_outstanding)
666 			return;
667 
668 		xgene_chan_xfer_request(chan, desc_sw);
669 
670 		/*
671 		 * Delete this element from ld pending queue and append it to
672 		 * ld running queue
673 		 */
674 		list_move_tail(&desc_sw->node, &chan->ld_running);
675 	}
676 }
677 
678 /**
679  * xgene_dma_cleanup_descriptors - cleanup link descriptors which are completed
680  * and move them to ld_completed to free until flag 'ack' is set
681  * @chan: X-Gene DMA channel
682  *
683  * This function is used on descriptors which have been executed by the DMA
684  * controller. It will run any callbacks, submit any dependencies, then
685  * free these descriptors if flag 'ack' is set.
686  */
687 static void xgene_dma_cleanup_descriptors(struct xgene_dma_chan *chan)
688 {
689 	struct xgene_dma_ring *ring = &chan->rx_ring;
690 	struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
691 	struct xgene_dma_desc_hw *desc_hw;
692 	struct list_head ld_completed;
693 	u8 status;
694 
695 	INIT_LIST_HEAD(&ld_completed);
696 
697 	spin_lock(&chan->lock);
698 
699 	/* Clean already completed and acked descriptors */
700 	xgene_dma_clean_completed_descriptor(chan);
701 
702 	/* Move all completed descriptors to ld completed queue, in order */
703 	list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_running, node) {
704 		/* Get subsequent hw descriptor from DMA rx ring */
705 		desc_hw = &ring->desc_hw[ring->head];
706 
707 		/* Check if this descriptor has been completed */
708 		if (unlikely(le64_to_cpu(desc_hw->m0) ==
709 			     XGENE_DMA_DESC_EMPTY_SIGNATURE))
710 			break;
711 
712 		if (++ring->head == ring->slots)
713 			ring->head = 0;
714 
715 		/* Check if we have any error with DMA transactions */
716 		status = XGENE_DMA_DESC_STATUS(
717 				XGENE_DMA_DESC_ELERR_RD(le64_to_cpu(
718 							desc_hw->m0)),
719 				XGENE_DMA_DESC_LERR_RD(le64_to_cpu(
720 						       desc_hw->m0)));
721 		if (status) {
722 			/* Print the DMA error type */
723 			chan_err(chan, "%s\n", xgene_dma_desc_err[status]);
724 
725 			/*
726 			 * We have DMA transactions error here. Dump DMA Tx
727 			 * and Rx descriptors for this request */
728 			XGENE_DMA_DESC_DUMP(&desc_sw->desc1,
729 					    "X-Gene DMA TX DESC1: ");
730 
731 			if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC)
732 				XGENE_DMA_DESC_DUMP(&desc_sw->desc2,
733 						    "X-Gene DMA TX DESC2: ");
734 
735 			XGENE_DMA_DESC_DUMP(desc_hw,
736 					    "X-Gene DMA RX ERR DESC: ");
737 		}
738 
739 		/* Notify the hw about this completed descriptor */
740 		iowrite32(-1, ring->cmd);
741 
742 		/* Mark this hw descriptor as processed */
743 		desc_hw->m0 = cpu_to_le64(XGENE_DMA_DESC_EMPTY_SIGNATURE);
744 
745 		/*
746 		 * Decrement the pending transaction count
747 		 * as we have processed one
748 		 */
749 		chan->pending -= ((desc_sw->flags &
750 				  XGENE_DMA_FLAG_64B_DESC) ? 2 : 1);
751 
752 		/*
753 		 * Delete this node from ld running queue and append it to
754 		 * ld completed queue for further processing
755 		 */
756 		list_move_tail(&desc_sw->node, &ld_completed);
757 	}
758 
759 	/*
760 	 * Start any pending transactions automatically
761 	 * In the ideal case, we keep the DMA controller busy while we go
762 	 * ahead and free the descriptors below.
763 	 */
764 	xgene_chan_xfer_ld_pending(chan);
765 
766 	spin_unlock(&chan->lock);
767 
768 	/* Run the callback for each descriptor, in order */
769 	list_for_each_entry_safe(desc_sw, _desc_sw, &ld_completed, node) {
770 		xgene_dma_run_tx_complete_actions(chan, desc_sw);
771 		xgene_dma_clean_running_descriptor(chan, desc_sw);
772 	}
773 }
774 
775 static int xgene_dma_alloc_chan_resources(struct dma_chan *dchan)
776 {
777 	struct xgene_dma_chan *chan = to_dma_chan(dchan);
778 
779 	/* Has this channel already been allocated? */
780 	if (chan->desc_pool)
781 		return 1;
782 
783 	chan->desc_pool = dma_pool_create(chan->name, chan->dev,
784 					  sizeof(struct xgene_dma_desc_sw),
785 					  0, 0);
786 	if (!chan->desc_pool) {
787 		chan_err(chan, "Failed to allocate descriptor pool\n");
788 		return -ENOMEM;
789 	}
790 
791 	chan_dbg(chan, "Allocate descriptor pool\n");
792 
793 	return 1;
794 }
795 
796 /**
797  * xgene_dma_free_desc_list - Free all descriptors in a queue
798  * @chan: X-Gene DMA channel
799  * @list: the list to free
800  *
801  * LOCKING: must hold chan->lock
802  */
803 static void xgene_dma_free_desc_list(struct xgene_dma_chan *chan,
804 				     struct list_head *list)
805 {
806 	struct xgene_dma_desc_sw *desc, *_desc;
807 
808 	list_for_each_entry_safe(desc, _desc, list, node)
809 		xgene_dma_clean_descriptor(chan, desc);
810 }
811 
812 static void xgene_dma_free_chan_resources(struct dma_chan *dchan)
813 {
814 	struct xgene_dma_chan *chan = to_dma_chan(dchan);
815 
816 	chan_dbg(chan, "Free all resources\n");
817 
818 	if (!chan->desc_pool)
819 		return;
820 
821 	/* Process all running descriptor */
822 	xgene_dma_cleanup_descriptors(chan);
823 
824 	spin_lock_bh(&chan->lock);
825 
826 	/* Clean all link descriptor queues */
827 	xgene_dma_free_desc_list(chan, &chan->ld_pending);
828 	xgene_dma_free_desc_list(chan, &chan->ld_running);
829 	xgene_dma_free_desc_list(chan, &chan->ld_completed);
830 
831 	spin_unlock_bh(&chan->lock);
832 
833 	/* Delete this channel DMA pool */
834 	dma_pool_destroy(chan->desc_pool);
835 	chan->desc_pool = NULL;
836 }
837 
838 static struct dma_async_tx_descriptor *xgene_dma_prep_xor(
839 	struct dma_chan *dchan, dma_addr_t dst,	dma_addr_t *src,
840 	u32 src_cnt, size_t len, unsigned long flags)
841 {
842 	struct xgene_dma_desc_sw *first = NULL, *new;
843 	struct xgene_dma_chan *chan;
844 	static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {
845 				0x01, 0x01, 0x01, 0x01, 0x01};
846 
847 	if (unlikely(!dchan || !len))
848 		return NULL;
849 
850 	chan = to_dma_chan(dchan);
851 
852 	do {
853 		/* Allocate the link descriptor from DMA pool */
854 		new = xgene_dma_alloc_descriptor(chan);
855 		if (!new)
856 			goto fail;
857 
858 		/* Prepare xor DMA descriptor */
859 		xgene_dma_prep_xor_desc(chan, new, &dst, src,
860 					src_cnt, &len, multi);
861 
862 		if (!first)
863 			first = new;
864 
865 		new->tx.cookie = 0;
866 		async_tx_ack(&new->tx);
867 
868 		/* Insert the link descriptor to the LD ring */
869 		list_add_tail(&new->node, &first->tx_list);
870 	} while (len);
871 
872 	new->tx.flags = flags; /* client is in control of this ack */
873 	new->tx.cookie = -EBUSY;
874 	list_splice(&first->tx_list, &new->tx_list);
875 
876 	return &new->tx;
877 
878 fail:
879 	if (!first)
880 		return NULL;
881 
882 	xgene_dma_free_desc_list(chan, &first->tx_list);
883 	return NULL;
884 }
885 
886 static struct dma_async_tx_descriptor *xgene_dma_prep_pq(
887 	struct dma_chan *dchan, dma_addr_t *dst, dma_addr_t *src,
888 	u32 src_cnt, const u8 *scf, size_t len, unsigned long flags)
889 {
890 	struct xgene_dma_desc_sw *first = NULL, *new;
891 	struct xgene_dma_chan *chan;
892 	size_t _len = len;
893 	dma_addr_t _src[XGENE_DMA_MAX_XOR_SRC];
894 	static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {0x01, 0x01, 0x01, 0x01, 0x01};
895 
896 	if (unlikely(!dchan || !len))
897 		return NULL;
898 
899 	chan = to_dma_chan(dchan);
900 
901 	/*
902 	 * Save source addresses on local variable, may be we have to
903 	 * prepare two descriptor to generate P and Q if both enabled
904 	 * in the flags by client
905 	 */
906 	memcpy(_src, src, sizeof(*src) * src_cnt);
907 
908 	if (flags & DMA_PREP_PQ_DISABLE_P)
909 		len = 0;
910 
911 	if (flags & DMA_PREP_PQ_DISABLE_Q)
912 		_len = 0;
913 
914 	do {
915 		/* Allocate the link descriptor from DMA pool */
916 		new = xgene_dma_alloc_descriptor(chan);
917 		if (!new)
918 			goto fail;
919 
920 		if (!first)
921 			first = new;
922 
923 		new->tx.cookie = 0;
924 		async_tx_ack(&new->tx);
925 
926 		/* Insert the link descriptor to the LD ring */
927 		list_add_tail(&new->node, &first->tx_list);
928 
929 		/*
930 		 * Prepare DMA descriptor to generate P,
931 		 * if DMA_PREP_PQ_DISABLE_P flag is not set
932 		 */
933 		if (len) {
934 			xgene_dma_prep_xor_desc(chan, new, &dst[0], src,
935 						src_cnt, &len, multi);
936 			continue;
937 		}
938 
939 		/*
940 		 * Prepare DMA descriptor to generate Q,
941 		 * if DMA_PREP_PQ_DISABLE_Q flag is not set
942 		 */
943 		if (_len) {
944 			xgene_dma_prep_xor_desc(chan, new, &dst[1], _src,
945 						src_cnt, &_len, scf);
946 		}
947 	} while (len || _len);
948 
949 	new->tx.flags = flags; /* client is in control of this ack */
950 	new->tx.cookie = -EBUSY;
951 	list_splice(&first->tx_list, &new->tx_list);
952 
953 	return &new->tx;
954 
955 fail:
956 	if (!first)
957 		return NULL;
958 
959 	xgene_dma_free_desc_list(chan, &first->tx_list);
960 	return NULL;
961 }
962 
963 static void xgene_dma_issue_pending(struct dma_chan *dchan)
964 {
965 	struct xgene_dma_chan *chan = to_dma_chan(dchan);
966 
967 	spin_lock_bh(&chan->lock);
968 	xgene_chan_xfer_ld_pending(chan);
969 	spin_unlock_bh(&chan->lock);
970 }
971 
972 static enum dma_status xgene_dma_tx_status(struct dma_chan *dchan,
973 					   dma_cookie_t cookie,
974 					   struct dma_tx_state *txstate)
975 {
976 	return dma_cookie_status(dchan, cookie, txstate);
977 }
978 
979 static void xgene_dma_tasklet_cb(struct tasklet_struct *t)
980 {
981 	struct xgene_dma_chan *chan = from_tasklet(chan, t, tasklet);
982 
983 	/* Run all cleanup for descriptors which have been completed */
984 	xgene_dma_cleanup_descriptors(chan);
985 
986 	/* Re-enable DMA channel IRQ */
987 	enable_irq(chan->rx_irq);
988 }
989 
990 static irqreturn_t xgene_dma_chan_ring_isr(int irq, void *id)
991 {
992 	struct xgene_dma_chan *chan = (struct xgene_dma_chan *)id;
993 
994 	BUG_ON(!chan);
995 
996 	/*
997 	 * Disable DMA channel IRQ until we process completed
998 	 * descriptors
999 	 */
1000 	disable_irq_nosync(chan->rx_irq);
1001 
1002 	/*
1003 	 * Schedule the tasklet to handle all cleanup of the current
1004 	 * transaction. It will start a new transaction if there is
1005 	 * one pending.
1006 	 */
1007 	tasklet_schedule(&chan->tasklet);
1008 
1009 	return IRQ_HANDLED;
1010 }
1011 
1012 static irqreturn_t xgene_dma_err_isr(int irq, void *id)
1013 {
1014 	struct xgene_dma *pdma = (struct xgene_dma *)id;
1015 	unsigned long int_mask;
1016 	u32 val, i;
1017 
1018 	val = ioread32(pdma->csr_dma + XGENE_DMA_INT);
1019 
1020 	/* Clear DMA interrupts */
1021 	iowrite32(val, pdma->csr_dma + XGENE_DMA_INT);
1022 
1023 	/* Print DMA error info */
1024 	int_mask = val >> XGENE_DMA_INT_MASK_SHIFT;
1025 	for_each_set_bit(i, &int_mask, ARRAY_SIZE(xgene_dma_err))
1026 		dev_err(pdma->dev,
1027 			"Interrupt status 0x%08X %s\n", val, xgene_dma_err[i]);
1028 
1029 	return IRQ_HANDLED;
1030 }
1031 
1032 static void xgene_dma_wr_ring_state(struct xgene_dma_ring *ring)
1033 {
1034 	int i;
1035 
1036 	iowrite32(ring->num, ring->pdma->csr_ring + XGENE_DMA_RING_STATE);
1037 
1038 	for (i = 0; i < XGENE_DMA_RING_NUM_CONFIG; i++)
1039 		iowrite32(ring->state[i], ring->pdma->csr_ring +
1040 			  XGENE_DMA_RING_STATE_WR_BASE + (i * 4));
1041 }
1042 
1043 static void xgene_dma_clr_ring_state(struct xgene_dma_ring *ring)
1044 {
1045 	memset(ring->state, 0, sizeof(u32) * XGENE_DMA_RING_NUM_CONFIG);
1046 	xgene_dma_wr_ring_state(ring);
1047 }
1048 
1049 static void xgene_dma_setup_ring(struct xgene_dma_ring *ring)
1050 {
1051 	void *ring_cfg = ring->state;
1052 	u64 addr = ring->desc_paddr;
1053 	u32 i, val;
1054 
1055 	ring->slots = ring->size / XGENE_DMA_RING_WQ_DESC_SIZE;
1056 
1057 	/* Clear DMA ring state */
1058 	xgene_dma_clr_ring_state(ring);
1059 
1060 	/* Set DMA ring type */
1061 	XGENE_DMA_RING_TYPE_SET(ring_cfg, XGENE_DMA_RING_TYPE_REGULAR);
1062 
1063 	if (ring->owner == XGENE_DMA_RING_OWNER_DMA) {
1064 		/* Set recombination buffer and timeout */
1065 		XGENE_DMA_RING_RECOMBBUF_SET(ring_cfg);
1066 		XGENE_DMA_RING_RECOMTIMEOUTL_SET(ring_cfg);
1067 		XGENE_DMA_RING_RECOMTIMEOUTH_SET(ring_cfg);
1068 	}
1069 
1070 	/* Initialize DMA ring state */
1071 	XGENE_DMA_RING_SELTHRSH_SET(ring_cfg);
1072 	XGENE_DMA_RING_ACCEPTLERR_SET(ring_cfg);
1073 	XGENE_DMA_RING_COHERENT_SET(ring_cfg);
1074 	XGENE_DMA_RING_ADDRL_SET(ring_cfg, addr);
1075 	XGENE_DMA_RING_ADDRH_SET(ring_cfg, addr);
1076 	XGENE_DMA_RING_SIZE_SET(ring_cfg, ring->cfgsize);
1077 
1078 	/* Write DMA ring configurations */
1079 	xgene_dma_wr_ring_state(ring);
1080 
1081 	/* Set DMA ring id */
1082 	iowrite32(XGENE_DMA_RING_ID_SETUP(ring->id),
1083 		  ring->pdma->csr_ring + XGENE_DMA_RING_ID);
1084 
1085 	/* Set DMA ring buffer */
1086 	iowrite32(XGENE_DMA_RING_ID_BUF_SETUP(ring->num),
1087 		  ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
1088 
1089 	if (ring->owner != XGENE_DMA_RING_OWNER_CPU)
1090 		return;
1091 
1092 	/* Set empty signature to DMA Rx ring descriptors */
1093 	for (i = 0; i < ring->slots; i++) {
1094 		struct xgene_dma_desc_hw *desc;
1095 
1096 		desc = &ring->desc_hw[i];
1097 		desc->m0 = cpu_to_le64(XGENE_DMA_DESC_EMPTY_SIGNATURE);
1098 	}
1099 
1100 	/* Enable DMA Rx ring interrupt */
1101 	val = ioread32(ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
1102 	XGENE_DMA_RING_NE_INT_MODE_SET(val, ring->buf_num);
1103 	iowrite32(val, ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
1104 }
1105 
1106 static void xgene_dma_clear_ring(struct xgene_dma_ring *ring)
1107 {
1108 	u32 ring_id, val;
1109 
1110 	if (ring->owner == XGENE_DMA_RING_OWNER_CPU) {
1111 		/* Disable DMA Rx ring interrupt */
1112 		val = ioread32(ring->pdma->csr_ring +
1113 			       XGENE_DMA_RING_NE_INT_MODE);
1114 		XGENE_DMA_RING_NE_INT_MODE_RESET(val, ring->buf_num);
1115 		iowrite32(val, ring->pdma->csr_ring +
1116 			  XGENE_DMA_RING_NE_INT_MODE);
1117 	}
1118 
1119 	/* Clear DMA ring state */
1120 	ring_id = XGENE_DMA_RING_ID_SETUP(ring->id);
1121 	iowrite32(ring_id, ring->pdma->csr_ring + XGENE_DMA_RING_ID);
1122 
1123 	iowrite32(0, ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
1124 	xgene_dma_clr_ring_state(ring);
1125 }
1126 
1127 static void xgene_dma_set_ring_cmd(struct xgene_dma_ring *ring)
1128 {
1129 	ring->cmd_base = ring->pdma->csr_ring_cmd +
1130 				XGENE_DMA_RING_CMD_BASE_OFFSET((ring->num -
1131 							  XGENE_DMA_RING_NUM));
1132 
1133 	ring->cmd = ring->cmd_base + XGENE_DMA_RING_CMD_OFFSET;
1134 }
1135 
1136 static int xgene_dma_get_ring_size(struct xgene_dma_chan *chan,
1137 				   enum xgene_dma_ring_cfgsize cfgsize)
1138 {
1139 	int size;
1140 
1141 	switch (cfgsize) {
1142 	case XGENE_DMA_RING_CFG_SIZE_512B:
1143 		size = 0x200;
1144 		break;
1145 	case XGENE_DMA_RING_CFG_SIZE_2KB:
1146 		size = 0x800;
1147 		break;
1148 	case XGENE_DMA_RING_CFG_SIZE_16KB:
1149 		size = 0x4000;
1150 		break;
1151 	case XGENE_DMA_RING_CFG_SIZE_64KB:
1152 		size = 0x10000;
1153 		break;
1154 	case XGENE_DMA_RING_CFG_SIZE_512KB:
1155 		size = 0x80000;
1156 		break;
1157 	default:
1158 		chan_err(chan, "Unsupported cfg ring size %d\n", cfgsize);
1159 		return -EINVAL;
1160 	}
1161 
1162 	return size;
1163 }
1164 
1165 static void xgene_dma_delete_ring_one(struct xgene_dma_ring *ring)
1166 {
1167 	/* Clear DMA ring configurations */
1168 	xgene_dma_clear_ring(ring);
1169 
1170 	/* De-allocate DMA ring descriptor */
1171 	if (ring->desc_vaddr) {
1172 		dma_free_coherent(ring->pdma->dev, ring->size,
1173 				  ring->desc_vaddr, ring->desc_paddr);
1174 		ring->desc_vaddr = NULL;
1175 	}
1176 }
1177 
1178 static void xgene_dma_delete_chan_rings(struct xgene_dma_chan *chan)
1179 {
1180 	xgene_dma_delete_ring_one(&chan->rx_ring);
1181 	xgene_dma_delete_ring_one(&chan->tx_ring);
1182 }
1183 
1184 static int xgene_dma_create_ring_one(struct xgene_dma_chan *chan,
1185 				     struct xgene_dma_ring *ring,
1186 				     enum xgene_dma_ring_cfgsize cfgsize)
1187 {
1188 	int ret;
1189 
1190 	/* Setup DMA ring descriptor variables */
1191 	ring->pdma = chan->pdma;
1192 	ring->cfgsize = cfgsize;
1193 	ring->num = chan->pdma->ring_num++;
1194 	ring->id = XGENE_DMA_RING_ID_GET(ring->owner, ring->buf_num);
1195 
1196 	ret = xgene_dma_get_ring_size(chan, cfgsize);
1197 	if (ret <= 0)
1198 		return ret;
1199 	ring->size = ret;
1200 
1201 	/* Allocate memory for DMA ring descriptor */
1202 	ring->desc_vaddr = dma_alloc_coherent(chan->dev, ring->size,
1203 					      &ring->desc_paddr, GFP_KERNEL);
1204 	if (!ring->desc_vaddr) {
1205 		chan_err(chan, "Failed to allocate ring desc\n");
1206 		return -ENOMEM;
1207 	}
1208 
1209 	/* Configure and enable DMA ring */
1210 	xgene_dma_set_ring_cmd(ring);
1211 	xgene_dma_setup_ring(ring);
1212 
1213 	return 0;
1214 }
1215 
1216 static int xgene_dma_create_chan_rings(struct xgene_dma_chan *chan)
1217 {
1218 	struct xgene_dma_ring *rx_ring = &chan->rx_ring;
1219 	struct xgene_dma_ring *tx_ring = &chan->tx_ring;
1220 	int ret;
1221 
1222 	/* Create DMA Rx ring descriptor */
1223 	rx_ring->owner = XGENE_DMA_RING_OWNER_CPU;
1224 	rx_ring->buf_num = XGENE_DMA_CPU_BUFNUM + chan->id;
1225 
1226 	ret = xgene_dma_create_ring_one(chan, rx_ring,
1227 					XGENE_DMA_RING_CFG_SIZE_64KB);
1228 	if (ret)
1229 		return ret;
1230 
1231 	chan_dbg(chan, "Rx ring id 0x%X num %d desc 0x%p\n",
1232 		 rx_ring->id, rx_ring->num, rx_ring->desc_vaddr);
1233 
1234 	/* Create DMA Tx ring descriptor */
1235 	tx_ring->owner = XGENE_DMA_RING_OWNER_DMA;
1236 	tx_ring->buf_num = XGENE_DMA_BUFNUM + chan->id;
1237 
1238 	ret = xgene_dma_create_ring_one(chan, tx_ring,
1239 					XGENE_DMA_RING_CFG_SIZE_64KB);
1240 	if (ret) {
1241 		xgene_dma_delete_ring_one(rx_ring);
1242 		return ret;
1243 	}
1244 
1245 	tx_ring->dst_ring_num = XGENE_DMA_RING_DST_ID(rx_ring->num);
1246 
1247 	chan_dbg(chan,
1248 		 "Tx ring id 0x%X num %d desc 0x%p\n",
1249 		 tx_ring->id, tx_ring->num, tx_ring->desc_vaddr);
1250 
1251 	/* Set the max outstanding request possible to this channel */
1252 	chan->max_outstanding = tx_ring->slots;
1253 
1254 	return ret;
1255 }
1256 
1257 static int xgene_dma_init_rings(struct xgene_dma *pdma)
1258 {
1259 	int ret, i, j;
1260 
1261 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1262 		ret = xgene_dma_create_chan_rings(&pdma->chan[i]);
1263 		if (ret) {
1264 			for (j = 0; j < i; j++)
1265 				xgene_dma_delete_chan_rings(&pdma->chan[j]);
1266 			return ret;
1267 		}
1268 	}
1269 
1270 	return ret;
1271 }
1272 
1273 static void xgene_dma_enable(struct xgene_dma *pdma)
1274 {
1275 	u32 val;
1276 
1277 	/* Configure and enable DMA engine */
1278 	val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
1279 	XGENE_DMA_CH_SETUP(val);
1280 	XGENE_DMA_ENABLE(val);
1281 	iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
1282 }
1283 
1284 static void xgene_dma_disable(struct xgene_dma *pdma)
1285 {
1286 	u32 val;
1287 
1288 	val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
1289 	XGENE_DMA_DISABLE(val);
1290 	iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
1291 }
1292 
1293 static void xgene_dma_mask_interrupts(struct xgene_dma *pdma)
1294 {
1295 	/*
1296 	 * Mask DMA ring overflow, underflow and
1297 	 * AXI write/read error interrupts
1298 	 */
1299 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1300 		  pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
1301 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1302 		  pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
1303 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1304 		  pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
1305 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1306 		  pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
1307 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1308 		  pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
1309 
1310 	/* Mask DMA error interrupts */
1311 	iowrite32(XGENE_DMA_INT_ALL_MASK, pdma->csr_dma + XGENE_DMA_INT_MASK);
1312 }
1313 
1314 static void xgene_dma_unmask_interrupts(struct xgene_dma *pdma)
1315 {
1316 	/*
1317 	 * Unmask DMA ring overflow, underflow and
1318 	 * AXI write/read error interrupts
1319 	 */
1320 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1321 		  pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
1322 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1323 		  pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
1324 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1325 		  pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
1326 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1327 		  pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
1328 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1329 		  pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
1330 
1331 	/* Unmask DMA error interrupts */
1332 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1333 		  pdma->csr_dma + XGENE_DMA_INT_MASK);
1334 }
1335 
1336 static void xgene_dma_init_hw(struct xgene_dma *pdma)
1337 {
1338 	u32 val;
1339 
1340 	/* Associate DMA ring to corresponding ring HW */
1341 	iowrite32(XGENE_DMA_ASSOC_RING_MNGR1,
1342 		  pdma->csr_dma + XGENE_DMA_CFG_RING_WQ_ASSOC);
1343 
1344 	/* Configure RAID6 polynomial control setting */
1345 	if (is_pq_enabled(pdma))
1346 		iowrite32(XGENE_DMA_RAID6_MULTI_CTRL(0x1D),
1347 			  pdma->csr_dma + XGENE_DMA_RAID6_CONT);
1348 	else
1349 		dev_info(pdma->dev, "PQ is disabled in HW\n");
1350 
1351 	xgene_dma_enable(pdma);
1352 	xgene_dma_unmask_interrupts(pdma);
1353 
1354 	/* Get DMA id and version info */
1355 	val = ioread32(pdma->csr_dma + XGENE_DMA_IPBRR);
1356 
1357 	/* DMA device info */
1358 	dev_info(pdma->dev,
1359 		 "X-Gene DMA v%d.%02d.%02d driver registered %d channels",
1360 		 XGENE_DMA_REV_NO_RD(val), XGENE_DMA_BUS_ID_RD(val),
1361 		 XGENE_DMA_DEV_ID_RD(val), XGENE_DMA_MAX_CHANNEL);
1362 }
1363 
1364 static int xgene_dma_init_ring_mngr(struct xgene_dma *pdma)
1365 {
1366 	if (ioread32(pdma->csr_ring + XGENE_DMA_RING_CLKEN) &&
1367 	    (!ioread32(pdma->csr_ring + XGENE_DMA_RING_SRST)))
1368 		return 0;
1369 
1370 	iowrite32(0x3, pdma->csr_ring + XGENE_DMA_RING_CLKEN);
1371 	iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_SRST);
1372 
1373 	/* Bring up memory */
1374 	iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
1375 
1376 	/* Force a barrier */
1377 	ioread32(pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
1378 
1379 	/* reset may take up to 1ms */
1380 	usleep_range(1000, 1100);
1381 
1382 	if (ioread32(pdma->csr_ring + XGENE_DMA_RING_BLK_MEM_RDY)
1383 		!= XGENE_DMA_RING_BLK_MEM_RDY_VAL) {
1384 		dev_err(pdma->dev,
1385 			"Failed to release ring mngr memory from shutdown\n");
1386 		return -ENODEV;
1387 	}
1388 
1389 	/* program threshold set 1 and all hysteresis */
1390 	iowrite32(XGENE_DMA_RING_THRESLD0_SET1_VAL,
1391 		  pdma->csr_ring + XGENE_DMA_RING_THRESLD0_SET1);
1392 	iowrite32(XGENE_DMA_RING_THRESLD1_SET1_VAL,
1393 		  pdma->csr_ring + XGENE_DMA_RING_THRESLD1_SET1);
1394 	iowrite32(XGENE_DMA_RING_HYSTERESIS_VAL,
1395 		  pdma->csr_ring + XGENE_DMA_RING_HYSTERESIS);
1396 
1397 	/* Enable QPcore and assign error queue */
1398 	iowrite32(XGENE_DMA_RING_ENABLE,
1399 		  pdma->csr_ring + XGENE_DMA_RING_CONFIG);
1400 
1401 	return 0;
1402 }
1403 
1404 static int xgene_dma_init_mem(struct xgene_dma *pdma)
1405 {
1406 	int ret;
1407 
1408 	ret = xgene_dma_init_ring_mngr(pdma);
1409 	if (ret)
1410 		return ret;
1411 
1412 	/* Bring up memory */
1413 	iowrite32(0x0, pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
1414 
1415 	/* Force a barrier */
1416 	ioread32(pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
1417 
1418 	/* reset may take up to 1ms */
1419 	usleep_range(1000, 1100);
1420 
1421 	if (ioread32(pdma->csr_dma + XGENE_DMA_BLK_MEM_RDY)
1422 		!= XGENE_DMA_BLK_MEM_RDY_VAL) {
1423 		dev_err(pdma->dev,
1424 			"Failed to release DMA memory from shutdown\n");
1425 		return -ENODEV;
1426 	}
1427 
1428 	return 0;
1429 }
1430 
1431 static int xgene_dma_request_irqs(struct xgene_dma *pdma)
1432 {
1433 	struct xgene_dma_chan *chan;
1434 	int ret, i, j;
1435 
1436 	/* Register DMA error irq */
1437 	ret = devm_request_irq(pdma->dev, pdma->err_irq, xgene_dma_err_isr,
1438 			       0, "dma_error", pdma);
1439 	if (ret) {
1440 		dev_err(pdma->dev,
1441 			"Failed to register error IRQ %d\n", pdma->err_irq);
1442 		return ret;
1443 	}
1444 
1445 	/* Register DMA channel rx irq */
1446 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1447 		chan = &pdma->chan[i];
1448 		irq_set_status_flags(chan->rx_irq, IRQ_DISABLE_UNLAZY);
1449 		ret = devm_request_irq(chan->dev, chan->rx_irq,
1450 				       xgene_dma_chan_ring_isr,
1451 				       0, chan->name, chan);
1452 		if (ret) {
1453 			chan_err(chan, "Failed to register Rx IRQ %d\n",
1454 				 chan->rx_irq);
1455 			devm_free_irq(pdma->dev, pdma->err_irq, pdma);
1456 
1457 			for (j = 0; j < i; j++) {
1458 				chan = &pdma->chan[i];
1459 				irq_clear_status_flags(chan->rx_irq, IRQ_DISABLE_UNLAZY);
1460 				devm_free_irq(chan->dev, chan->rx_irq, chan);
1461 			}
1462 
1463 			return ret;
1464 		}
1465 	}
1466 
1467 	return 0;
1468 }
1469 
1470 static void xgene_dma_free_irqs(struct xgene_dma *pdma)
1471 {
1472 	struct xgene_dma_chan *chan;
1473 	int i;
1474 
1475 	/* Free DMA device error irq */
1476 	devm_free_irq(pdma->dev, pdma->err_irq, pdma);
1477 
1478 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1479 		chan = &pdma->chan[i];
1480 		irq_clear_status_flags(chan->rx_irq, IRQ_DISABLE_UNLAZY);
1481 		devm_free_irq(chan->dev, chan->rx_irq, chan);
1482 	}
1483 }
1484 
1485 static void xgene_dma_set_caps(struct xgene_dma_chan *chan,
1486 			       struct dma_device *dma_dev)
1487 {
1488 	/* Initialize DMA device capability mask */
1489 	dma_cap_zero(dma_dev->cap_mask);
1490 
1491 	/* Set DMA device capability */
1492 
1493 	/* Basically here, the X-Gene SoC DMA engine channel 0 supports XOR
1494 	 * and channel 1 supports XOR, PQ both. First thing here is we have
1495 	 * mechanism in hw to enable/disable PQ/XOR supports on channel 1,
1496 	 * we can make sure this by reading SoC Efuse register.
1497 	 * Second thing, we have hw errata that if we run channel 0 and
1498 	 * channel 1 simultaneously with executing XOR and PQ request,
1499 	 * suddenly DMA engine hangs, So here we enable XOR on channel 0 only
1500 	 * if XOR and PQ supports on channel 1 is disabled.
1501 	 */
1502 	if ((chan->id == XGENE_DMA_PQ_CHANNEL) &&
1503 	    is_pq_enabled(chan->pdma)) {
1504 		dma_cap_set(DMA_PQ, dma_dev->cap_mask);
1505 		dma_cap_set(DMA_XOR, dma_dev->cap_mask);
1506 	} else if ((chan->id == XGENE_DMA_XOR_CHANNEL) &&
1507 		   !is_pq_enabled(chan->pdma)) {
1508 		dma_cap_set(DMA_XOR, dma_dev->cap_mask);
1509 	}
1510 
1511 	/* Set base and prep routines */
1512 	dma_dev->dev = chan->dev;
1513 	dma_dev->device_alloc_chan_resources = xgene_dma_alloc_chan_resources;
1514 	dma_dev->device_free_chan_resources = xgene_dma_free_chan_resources;
1515 	dma_dev->device_issue_pending = xgene_dma_issue_pending;
1516 	dma_dev->device_tx_status = xgene_dma_tx_status;
1517 
1518 	if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
1519 		dma_dev->device_prep_dma_xor = xgene_dma_prep_xor;
1520 		dma_dev->max_xor = XGENE_DMA_MAX_XOR_SRC;
1521 		dma_dev->xor_align = DMAENGINE_ALIGN_64_BYTES;
1522 	}
1523 
1524 	if (dma_has_cap(DMA_PQ, dma_dev->cap_mask)) {
1525 		dma_dev->device_prep_dma_pq = xgene_dma_prep_pq;
1526 		dma_dev->max_pq = XGENE_DMA_MAX_XOR_SRC;
1527 		dma_dev->pq_align = DMAENGINE_ALIGN_64_BYTES;
1528 	}
1529 }
1530 
1531 static int xgene_dma_async_register(struct xgene_dma *pdma, int id)
1532 {
1533 	struct xgene_dma_chan *chan = &pdma->chan[id];
1534 	struct dma_device *dma_dev = &pdma->dma_dev[id];
1535 	int ret;
1536 
1537 	chan->dma_chan.device = dma_dev;
1538 
1539 	spin_lock_init(&chan->lock);
1540 	INIT_LIST_HEAD(&chan->ld_pending);
1541 	INIT_LIST_HEAD(&chan->ld_running);
1542 	INIT_LIST_HEAD(&chan->ld_completed);
1543 	tasklet_setup(&chan->tasklet, xgene_dma_tasklet_cb);
1544 
1545 	chan->pending = 0;
1546 	chan->desc_pool = NULL;
1547 	dma_cookie_init(&chan->dma_chan);
1548 
1549 	/* Setup dma device capabilities and prep routines */
1550 	xgene_dma_set_caps(chan, dma_dev);
1551 
1552 	/* Initialize DMA device list head */
1553 	INIT_LIST_HEAD(&dma_dev->channels);
1554 	list_add_tail(&chan->dma_chan.device_node, &dma_dev->channels);
1555 
1556 	/* Register with Linux async DMA framework*/
1557 	ret = dma_async_device_register(dma_dev);
1558 	if (ret) {
1559 		chan_err(chan, "Failed to register async device %d", ret);
1560 		tasklet_kill(&chan->tasklet);
1561 
1562 		return ret;
1563 	}
1564 
1565 	/* DMA capability info */
1566 	dev_info(pdma->dev,
1567 		 "%s: CAPABILITY ( %s%s)\n", dma_chan_name(&chan->dma_chan),
1568 		 dma_has_cap(DMA_XOR, dma_dev->cap_mask) ? "XOR " : "",
1569 		 dma_has_cap(DMA_PQ, dma_dev->cap_mask) ? "PQ " : "");
1570 
1571 	return 0;
1572 }
1573 
1574 static int xgene_dma_init_async(struct xgene_dma *pdma)
1575 {
1576 	int ret, i, j;
1577 
1578 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL ; i++) {
1579 		ret = xgene_dma_async_register(pdma, i);
1580 		if (ret) {
1581 			for (j = 0; j < i; j++) {
1582 				dma_async_device_unregister(&pdma->dma_dev[j]);
1583 				tasklet_kill(&pdma->chan[j].tasklet);
1584 			}
1585 
1586 			return ret;
1587 		}
1588 	}
1589 
1590 	return ret;
1591 }
1592 
1593 static void xgene_dma_async_unregister(struct xgene_dma *pdma)
1594 {
1595 	int i;
1596 
1597 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
1598 		dma_async_device_unregister(&pdma->dma_dev[i]);
1599 }
1600 
1601 static void xgene_dma_init_channels(struct xgene_dma *pdma)
1602 {
1603 	struct xgene_dma_chan *chan;
1604 	int i;
1605 
1606 	pdma->ring_num = XGENE_DMA_RING_NUM;
1607 
1608 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1609 		chan = &pdma->chan[i];
1610 		chan->dev = pdma->dev;
1611 		chan->pdma = pdma;
1612 		chan->id = i;
1613 		snprintf(chan->name, sizeof(chan->name), "dmachan%d", chan->id);
1614 	}
1615 }
1616 
1617 static int xgene_dma_get_resources(struct platform_device *pdev,
1618 				   struct xgene_dma *pdma)
1619 {
1620 	struct resource *res;
1621 	int irq, i;
1622 
1623 	/* Get DMA csr region */
1624 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1625 	if (!res) {
1626 		dev_err(&pdev->dev, "Failed to get csr region\n");
1627 		return -ENXIO;
1628 	}
1629 
1630 	pdma->csr_dma = devm_ioremap(&pdev->dev, res->start,
1631 				     resource_size(res));
1632 	if (!pdma->csr_dma) {
1633 		dev_err(&pdev->dev, "Failed to ioremap csr region");
1634 		return -ENOMEM;
1635 	}
1636 
1637 	/* Get DMA ring csr region */
1638 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1639 	if (!res) {
1640 		dev_err(&pdev->dev, "Failed to get ring csr region\n");
1641 		return -ENXIO;
1642 	}
1643 
1644 	pdma->csr_ring =  devm_ioremap(&pdev->dev, res->start,
1645 				       resource_size(res));
1646 	if (!pdma->csr_ring) {
1647 		dev_err(&pdev->dev, "Failed to ioremap ring csr region");
1648 		return -ENOMEM;
1649 	}
1650 
1651 	/* Get DMA ring cmd csr region */
1652 	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
1653 	if (!res) {
1654 		dev_err(&pdev->dev, "Failed to get ring cmd csr region\n");
1655 		return -ENXIO;
1656 	}
1657 
1658 	pdma->csr_ring_cmd = devm_ioremap(&pdev->dev, res->start,
1659 					  resource_size(res));
1660 	if (!pdma->csr_ring_cmd) {
1661 		dev_err(&pdev->dev, "Failed to ioremap ring cmd csr region");
1662 		return -ENOMEM;
1663 	}
1664 
1665 	pdma->csr_ring_cmd += XGENE_DMA_RING_CMD_SM_OFFSET;
1666 
1667 	/* Get efuse csr region */
1668 	res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
1669 	if (!res) {
1670 		dev_err(&pdev->dev, "Failed to get efuse csr region\n");
1671 		return -ENXIO;
1672 	}
1673 
1674 	pdma->csr_efuse = devm_ioremap(&pdev->dev, res->start,
1675 				       resource_size(res));
1676 	if (!pdma->csr_efuse) {
1677 		dev_err(&pdev->dev, "Failed to ioremap efuse csr region");
1678 		return -ENOMEM;
1679 	}
1680 
1681 	/* Get DMA error interrupt */
1682 	irq = platform_get_irq(pdev, 0);
1683 	if (irq <= 0)
1684 		return -ENXIO;
1685 
1686 	pdma->err_irq = irq;
1687 
1688 	/* Get DMA Rx ring descriptor interrupts for all DMA channels */
1689 	for (i = 1; i <= XGENE_DMA_MAX_CHANNEL; i++) {
1690 		irq = platform_get_irq(pdev, i);
1691 		if (irq <= 0)
1692 			return -ENXIO;
1693 
1694 		pdma->chan[i - 1].rx_irq = irq;
1695 	}
1696 
1697 	return 0;
1698 }
1699 
1700 static int xgene_dma_probe(struct platform_device *pdev)
1701 {
1702 	struct xgene_dma *pdma;
1703 	int ret, i;
1704 
1705 	pdma = devm_kzalloc(&pdev->dev, sizeof(*pdma), GFP_KERNEL);
1706 	if (!pdma)
1707 		return -ENOMEM;
1708 
1709 	pdma->dev = &pdev->dev;
1710 	platform_set_drvdata(pdev, pdma);
1711 
1712 	ret = xgene_dma_get_resources(pdev, pdma);
1713 	if (ret)
1714 		return ret;
1715 
1716 	pdma->clk = devm_clk_get(&pdev->dev, NULL);
1717 	if (IS_ERR(pdma->clk) && !ACPI_COMPANION(&pdev->dev)) {
1718 		dev_err(&pdev->dev, "Failed to get clk\n");
1719 		return PTR_ERR(pdma->clk);
1720 	}
1721 
1722 	/* Enable clk before accessing registers */
1723 	if (!IS_ERR(pdma->clk)) {
1724 		ret = clk_prepare_enable(pdma->clk);
1725 		if (ret) {
1726 			dev_err(&pdev->dev, "Failed to enable clk %d\n", ret);
1727 			return ret;
1728 		}
1729 	}
1730 
1731 	/* Remove DMA RAM out of shutdown */
1732 	ret = xgene_dma_init_mem(pdma);
1733 	if (ret)
1734 		goto err_clk_enable;
1735 
1736 	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(42));
1737 	if (ret) {
1738 		dev_err(&pdev->dev, "No usable DMA configuration\n");
1739 		goto err_dma_mask;
1740 	}
1741 
1742 	/* Initialize DMA channels software state */
1743 	xgene_dma_init_channels(pdma);
1744 
1745 	/* Configure DMA rings */
1746 	ret = xgene_dma_init_rings(pdma);
1747 	if (ret)
1748 		goto err_clk_enable;
1749 
1750 	ret = xgene_dma_request_irqs(pdma);
1751 	if (ret)
1752 		goto err_request_irq;
1753 
1754 	/* Configure and enable DMA engine */
1755 	xgene_dma_init_hw(pdma);
1756 
1757 	/* Register DMA device with linux async framework */
1758 	ret = xgene_dma_init_async(pdma);
1759 	if (ret)
1760 		goto err_async_init;
1761 
1762 	return 0;
1763 
1764 err_async_init:
1765 	xgene_dma_free_irqs(pdma);
1766 
1767 err_request_irq:
1768 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
1769 		xgene_dma_delete_chan_rings(&pdma->chan[i]);
1770 
1771 err_dma_mask:
1772 err_clk_enable:
1773 	if (!IS_ERR(pdma->clk))
1774 		clk_disable_unprepare(pdma->clk);
1775 
1776 	return ret;
1777 }
1778 
1779 static void xgene_dma_remove(struct platform_device *pdev)
1780 {
1781 	struct xgene_dma *pdma = platform_get_drvdata(pdev);
1782 	struct xgene_dma_chan *chan;
1783 	int i;
1784 
1785 	xgene_dma_async_unregister(pdma);
1786 
1787 	/* Mask interrupts and disable DMA engine */
1788 	xgene_dma_mask_interrupts(pdma);
1789 	xgene_dma_disable(pdma);
1790 	xgene_dma_free_irqs(pdma);
1791 
1792 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1793 		chan = &pdma->chan[i];
1794 		tasklet_kill(&chan->tasklet);
1795 		xgene_dma_delete_chan_rings(chan);
1796 	}
1797 
1798 	if (!IS_ERR(pdma->clk))
1799 		clk_disable_unprepare(pdma->clk);
1800 }
1801 
1802 #ifdef CONFIG_ACPI
1803 static const struct acpi_device_id xgene_dma_acpi_match_ptr[] = {
1804 	{"APMC0D43", 0},
1805 	{},
1806 };
1807 MODULE_DEVICE_TABLE(acpi, xgene_dma_acpi_match_ptr);
1808 #endif
1809 
1810 static const struct of_device_id xgene_dma_of_match_ptr[] = {
1811 	{.compatible = "apm,xgene-storm-dma",},
1812 	{},
1813 };
1814 MODULE_DEVICE_TABLE(of, xgene_dma_of_match_ptr);
1815 
1816 static struct platform_driver xgene_dma_driver = {
1817 	.probe = xgene_dma_probe,
1818 	.remove_new = xgene_dma_remove,
1819 	.driver = {
1820 		.name = "X-Gene-DMA",
1821 		.of_match_table = xgene_dma_of_match_ptr,
1822 		.acpi_match_table = ACPI_PTR(xgene_dma_acpi_match_ptr),
1823 	},
1824 };
1825 
1826 module_platform_driver(xgene_dma_driver);
1827 
1828 MODULE_DESCRIPTION("APM X-Gene SoC DMA driver");
1829 MODULE_AUTHOR("Rameshwar Prasad Sahu <rsahu@apm.com>");
1830 MODULE_AUTHOR("Loc Ho <lho@apm.com>");
1831 MODULE_LICENSE("GPL");
1832 MODULE_VERSION("1.0");
1833