xref: /openbmc/linux/drivers/dma/xgene-dma.c (revision 2cf1c348)
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/module.h>
22 #include <linux/of_device.h>
23 
24 #include "dmaengine.h"
25 
26 /* X-Gene DMA ring csr registers and bit definations */
27 #define XGENE_DMA_RING_CONFIG			0x04
28 #define XGENE_DMA_RING_ENABLE			BIT(31)
29 #define XGENE_DMA_RING_ID			0x08
30 #define XGENE_DMA_RING_ID_SETUP(v)		((v) | BIT(31))
31 #define XGENE_DMA_RING_ID_BUF			0x0C
32 #define XGENE_DMA_RING_ID_BUF_SETUP(v)		(((v) << 9) | BIT(21))
33 #define XGENE_DMA_RING_THRESLD0_SET1		0x30
34 #define XGENE_DMA_RING_THRESLD0_SET1_VAL	0X64
35 #define XGENE_DMA_RING_THRESLD1_SET1		0x34
36 #define XGENE_DMA_RING_THRESLD1_SET1_VAL	0xC8
37 #define XGENE_DMA_RING_HYSTERESIS		0x68
38 #define XGENE_DMA_RING_HYSTERESIS_VAL		0xFFFFFFFF
39 #define XGENE_DMA_RING_STATE			0x6C
40 #define XGENE_DMA_RING_STATE_WR_BASE		0x70
41 #define XGENE_DMA_RING_NE_INT_MODE		0x017C
42 #define XGENE_DMA_RING_NE_INT_MODE_SET(m, v)	\
43 	((m) = ((m) & ~BIT(31 - (v))) | BIT(31 - (v)))
44 #define XGENE_DMA_RING_NE_INT_MODE_RESET(m, v)	\
45 	((m) &= (~BIT(31 - (v))))
46 #define XGENE_DMA_RING_CLKEN			0xC208
47 #define XGENE_DMA_RING_SRST			0xC200
48 #define XGENE_DMA_RING_MEM_RAM_SHUTDOWN		0xD070
49 #define XGENE_DMA_RING_BLK_MEM_RDY		0xD074
50 #define XGENE_DMA_RING_BLK_MEM_RDY_VAL		0xFFFFFFFF
51 #define XGENE_DMA_RING_ID_GET(owner, num)	(((owner) << 6) | (num))
52 #define XGENE_DMA_RING_DST_ID(v)		((1 << 10) | (v))
53 #define XGENE_DMA_RING_CMD_OFFSET		0x2C
54 #define XGENE_DMA_RING_CMD_BASE_OFFSET(v)	((v) << 6)
55 #define XGENE_DMA_RING_COHERENT_SET(m)		\
56 	(((u32 *)(m))[2] |= BIT(4))
57 #define XGENE_DMA_RING_ADDRL_SET(m, v)		\
58 	(((u32 *)(m))[2] |= (((v) >> 8) << 5))
59 #define XGENE_DMA_RING_ADDRH_SET(m, v)		\
60 	(((u32 *)(m))[3] |= ((v) >> 35))
61 #define XGENE_DMA_RING_ACCEPTLERR_SET(m)	\
62 	(((u32 *)(m))[3] |= BIT(19))
63 #define XGENE_DMA_RING_SIZE_SET(m, v)		\
64 	(((u32 *)(m))[3] |= ((v) << 23))
65 #define XGENE_DMA_RING_RECOMBBUF_SET(m)		\
66 	(((u32 *)(m))[3] |= BIT(27))
67 #define XGENE_DMA_RING_RECOMTIMEOUTL_SET(m)	\
68 	(((u32 *)(m))[3] |= (0x7 << 28))
69 #define XGENE_DMA_RING_RECOMTIMEOUTH_SET(m)	\
70 	(((u32 *)(m))[4] |= 0x3)
71 #define XGENE_DMA_RING_SELTHRSH_SET(m)		\
72 	(((u32 *)(m))[4] |= BIT(3))
73 #define XGENE_DMA_RING_TYPE_SET(m, v)		\
74 	(((u32 *)(m))[4] |= ((v) << 19))
75 
76 /* X-Gene DMA device csr registers and bit definitions */
77 #define XGENE_DMA_IPBRR				0x0
78 #define XGENE_DMA_DEV_ID_RD(v)			((v) & 0x00000FFF)
79 #define XGENE_DMA_BUS_ID_RD(v)			(((v) >> 12) & 3)
80 #define XGENE_DMA_REV_NO_RD(v)			(((v) >> 14) & 3)
81 #define XGENE_DMA_GCR				0x10
82 #define XGENE_DMA_CH_SETUP(v)			\
83 	((v) = ((v) & ~0x000FFFFF) | 0x000AAFFF)
84 #define XGENE_DMA_ENABLE(v)			((v) |= BIT(31))
85 #define XGENE_DMA_DISABLE(v)			((v) &= ~BIT(31))
86 #define XGENE_DMA_RAID6_CONT			0x14
87 #define XGENE_DMA_RAID6_MULTI_CTRL(v)		((v) << 24)
88 #define XGENE_DMA_INT				0x70
89 #define XGENE_DMA_INT_MASK			0x74
90 #define XGENE_DMA_INT_ALL_MASK			0xFFFFFFFF
91 #define XGENE_DMA_INT_ALL_UNMASK		0x0
92 #define XGENE_DMA_INT_MASK_SHIFT		0x14
93 #define XGENE_DMA_RING_INT0_MASK		0x90A0
94 #define XGENE_DMA_RING_INT1_MASK		0x90A8
95 #define XGENE_DMA_RING_INT2_MASK		0x90B0
96 #define XGENE_DMA_RING_INT3_MASK		0x90B8
97 #define XGENE_DMA_RING_INT4_MASK		0x90C0
98 #define XGENE_DMA_CFG_RING_WQ_ASSOC		0x90E0
99 #define XGENE_DMA_ASSOC_RING_MNGR1		0xFFFFFFFF
100 #define XGENE_DMA_MEM_RAM_SHUTDOWN		0xD070
101 #define XGENE_DMA_BLK_MEM_RDY			0xD074
102 #define XGENE_DMA_BLK_MEM_RDY_VAL		0xFFFFFFFF
103 #define XGENE_DMA_RING_CMD_SM_OFFSET		0x8000
104 
105 /* X-Gene SoC EFUSE csr register and bit defination */
106 #define XGENE_SOC_JTAG1_SHADOW			0x18
107 #define XGENE_DMA_PQ_DISABLE_MASK		BIT(13)
108 
109 /* X-Gene DMA Descriptor format */
110 #define XGENE_DMA_DESC_NV_BIT			BIT_ULL(50)
111 #define XGENE_DMA_DESC_IN_BIT			BIT_ULL(55)
112 #define XGENE_DMA_DESC_C_BIT			BIT_ULL(63)
113 #define XGENE_DMA_DESC_DR_BIT			BIT_ULL(61)
114 #define XGENE_DMA_DESC_ELERR_POS		46
115 #define XGENE_DMA_DESC_RTYPE_POS		56
116 #define XGENE_DMA_DESC_LERR_POS			60
117 #define XGENE_DMA_DESC_BUFLEN_POS		48
118 #define XGENE_DMA_DESC_HOENQ_NUM_POS		48
119 #define XGENE_DMA_DESC_ELERR_RD(m)		\
120 	(((m) >> XGENE_DMA_DESC_ELERR_POS) & 0x3)
121 #define XGENE_DMA_DESC_LERR_RD(m)		\
122 	(((m) >> XGENE_DMA_DESC_LERR_POS) & 0x7)
123 #define XGENE_DMA_DESC_STATUS(elerr, lerr)	\
124 	(((elerr) << 4) | (lerr))
125 
126 /* X-Gene DMA descriptor empty s/w signature */
127 #define XGENE_DMA_DESC_EMPTY_SIGNATURE		~0ULL
128 
129 /* X-Gene DMA configurable parameters defines */
130 #define XGENE_DMA_RING_NUM		512
131 #define XGENE_DMA_BUFNUM		0x0
132 #define XGENE_DMA_CPU_BUFNUM		0x18
133 #define XGENE_DMA_RING_OWNER_DMA	0x03
134 #define XGENE_DMA_RING_OWNER_CPU	0x0F
135 #define XGENE_DMA_RING_TYPE_REGULAR	0x01
136 #define XGENE_DMA_RING_WQ_DESC_SIZE	32	/* 32 Bytes */
137 #define XGENE_DMA_RING_NUM_CONFIG	5
138 #define XGENE_DMA_MAX_CHANNEL		4
139 #define XGENE_DMA_XOR_CHANNEL		0
140 #define XGENE_DMA_PQ_CHANNEL		1
141 #define XGENE_DMA_MAX_BYTE_CNT		0x4000	/* 16 KB */
142 #define XGENE_DMA_MAX_64B_DESC_BYTE_CNT	0x14000	/* 80 KB */
143 #define XGENE_DMA_MAX_XOR_SRC		5
144 #define XGENE_DMA_16K_BUFFER_LEN_CODE	0x0
145 #define XGENE_DMA_INVALID_LEN_CODE	0x7800000000000000ULL
146 
147 /* X-Gene DMA descriptor error codes */
148 #define ERR_DESC_AXI			0x01
149 #define ERR_BAD_DESC			0x02
150 #define ERR_READ_DATA_AXI		0x03
151 #define ERR_WRITE_DATA_AXI		0x04
152 #define ERR_FBP_TIMEOUT			0x05
153 #define ERR_ECC				0x06
154 #define ERR_DIFF_SIZE			0x08
155 #define ERR_SCT_GAT_LEN			0x09
156 #define ERR_CRC_ERR			0x11
157 #define ERR_CHKSUM			0x12
158 #define ERR_DIF				0x13
159 
160 /* X-Gene DMA error interrupt codes */
161 #define ERR_DIF_SIZE_INT		0x0
162 #define ERR_GS_ERR_INT			0x1
163 #define ERR_FPB_TIMEO_INT		0x2
164 #define ERR_WFIFO_OVF_INT		0x3
165 #define ERR_RFIFO_OVF_INT		0x4
166 #define ERR_WR_TIMEO_INT		0x5
167 #define ERR_RD_TIMEO_INT		0x6
168 #define ERR_WR_ERR_INT			0x7
169 #define ERR_RD_ERR_INT			0x8
170 #define ERR_BAD_DESC_INT		0x9
171 #define ERR_DESC_DST_INT		0xA
172 #define ERR_DESC_SRC_INT		0xB
173 
174 /* X-Gene DMA flyby operation code */
175 #define FLYBY_2SRC_XOR			0x80
176 #define FLYBY_3SRC_XOR			0x90
177 #define FLYBY_4SRC_XOR			0xA0
178 #define FLYBY_5SRC_XOR			0xB0
179 
180 /* X-Gene DMA SW descriptor flags */
181 #define XGENE_DMA_FLAG_64B_DESC		BIT(0)
182 
183 /* Define to dump X-Gene DMA descriptor */
184 #define XGENE_DMA_DESC_DUMP(desc, m)	\
185 	print_hex_dump(KERN_ERR, (m),	\
186 			DUMP_PREFIX_ADDRESS, 16, 8, (desc), 32, 0)
187 
188 #define to_dma_desc_sw(tx)		\
189 	container_of(tx, struct xgene_dma_desc_sw, tx)
190 #define to_dma_chan(dchan)		\
191 	container_of(dchan, struct xgene_dma_chan, dma_chan)
192 
193 #define chan_dbg(chan, fmt, arg...)	\
194 	dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
195 #define chan_err(chan, fmt, arg...)	\
196 	dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
197 
198 struct xgene_dma_desc_hw {
199 	__le64 m0;
200 	__le64 m1;
201 	__le64 m2;
202 	__le64 m3;
203 };
204 
205 enum xgene_dma_ring_cfgsize {
206 	XGENE_DMA_RING_CFG_SIZE_512B,
207 	XGENE_DMA_RING_CFG_SIZE_2KB,
208 	XGENE_DMA_RING_CFG_SIZE_16KB,
209 	XGENE_DMA_RING_CFG_SIZE_64KB,
210 	XGENE_DMA_RING_CFG_SIZE_512KB,
211 	XGENE_DMA_RING_CFG_SIZE_INVALID
212 };
213 
214 struct xgene_dma_ring {
215 	struct xgene_dma *pdma;
216 	u8 buf_num;
217 	u16 id;
218 	u16 num;
219 	u16 head;
220 	u16 owner;
221 	u16 slots;
222 	u16 dst_ring_num;
223 	u32 size;
224 	void __iomem *cmd;
225 	void __iomem *cmd_base;
226 	dma_addr_t desc_paddr;
227 	u32 state[XGENE_DMA_RING_NUM_CONFIG];
228 	enum xgene_dma_ring_cfgsize cfgsize;
229 	union {
230 		void *desc_vaddr;
231 		struct xgene_dma_desc_hw *desc_hw;
232 	};
233 };
234 
235 struct xgene_dma_desc_sw {
236 	struct xgene_dma_desc_hw desc1;
237 	struct xgene_dma_desc_hw desc2;
238 	u32 flags;
239 	struct list_head node;
240 	struct list_head tx_list;
241 	struct dma_async_tx_descriptor tx;
242 };
243 
244 /**
245  * struct xgene_dma_chan - internal representation of an X-Gene DMA channel
246  * @dma_chan: dmaengine channel object member
247  * @pdma: X-Gene DMA device structure reference
248  * @dev: struct device reference for dma mapping api
249  * @id: raw id of this channel
250  * @rx_irq: channel IRQ
251  * @name: name of X-Gene DMA channel
252  * @lock: serializes enqueue/dequeue operations to the descriptor pool
253  * @pending: number of transaction request pushed to DMA controller for
254  *	execution, but still waiting for completion,
255  * @max_outstanding: max number of outstanding request we can push to channel
256  * @ld_pending: descriptors which are queued to run, but have not yet been
257  *	submitted to the hardware for execution
258  * @ld_running: descriptors which are currently being executing by the hardware
259  * @ld_completed: descriptors which have finished execution by the hardware.
260  *	These descriptors have already had their cleanup actions run. They
261  *	are waiting for the ACK bit to be set by the async tx API.
262  * @desc_pool: descriptor pool for DMA operations
263  * @tasklet: bottom half where all completed descriptors cleans
264  * @tx_ring: transmit ring descriptor that we use to prepare actual
265  *	descriptors for further executions
266  * @rx_ring: receive ring descriptor that we use to get completed DMA
267  *	descriptors during cleanup time
268  */
269 struct xgene_dma_chan {
270 	struct dma_chan dma_chan;
271 	struct xgene_dma *pdma;
272 	struct device *dev;
273 	int id;
274 	int rx_irq;
275 	char name[10];
276 	spinlock_t lock;
277 	int pending;
278 	int max_outstanding;
279 	struct list_head ld_pending;
280 	struct list_head ld_running;
281 	struct list_head ld_completed;
282 	struct dma_pool *desc_pool;
283 	struct tasklet_struct tasklet;
284 	struct xgene_dma_ring tx_ring;
285 	struct xgene_dma_ring rx_ring;
286 };
287 
288 /**
289  * struct xgene_dma - internal representation of an X-Gene DMA device
290  * @dev: reference to this device's struct device
291  * @clk: reference to this device's clock
292  * @err_irq: DMA error irq number
293  * @ring_num: start id number for DMA ring
294  * @csr_dma: base for DMA register access
295  * @csr_ring: base for DMA ring register access
296  * @csr_ring_cmd: base for DMA ring command register access
297  * @csr_efuse: base for efuse register access
298  * @dma_dev: embedded struct dma_device
299  * @chan: reference to X-Gene DMA channels
300  */
301 struct xgene_dma {
302 	struct device *dev;
303 	struct clk *clk;
304 	int err_irq;
305 	int ring_num;
306 	void __iomem *csr_dma;
307 	void __iomem *csr_ring;
308 	void __iomem *csr_ring_cmd;
309 	void __iomem *csr_efuse;
310 	struct dma_device dma_dev[XGENE_DMA_MAX_CHANNEL];
311 	struct xgene_dma_chan chan[XGENE_DMA_MAX_CHANNEL];
312 };
313 
314 static const char * const xgene_dma_desc_err[] = {
315 	[ERR_DESC_AXI] = "AXI error when reading src/dst link list",
316 	[ERR_BAD_DESC] = "ERR or El_ERR fields not set to zero in desc",
317 	[ERR_READ_DATA_AXI] = "AXI error when reading data",
318 	[ERR_WRITE_DATA_AXI] = "AXI error when writing data",
319 	[ERR_FBP_TIMEOUT] = "Timeout on bufpool fetch",
320 	[ERR_ECC] = "ECC double bit error",
321 	[ERR_DIFF_SIZE] = "Bufpool too small to hold all the DIF result",
322 	[ERR_SCT_GAT_LEN] = "Gather and scatter data length not same",
323 	[ERR_CRC_ERR] = "CRC error",
324 	[ERR_CHKSUM] = "Checksum error",
325 	[ERR_DIF] = "DIF error",
326 };
327 
328 static const char * const xgene_dma_err[] = {
329 	[ERR_DIF_SIZE_INT] = "DIF size error",
330 	[ERR_GS_ERR_INT] = "Gather scatter not same size error",
331 	[ERR_FPB_TIMEO_INT] = "Free pool time out error",
332 	[ERR_WFIFO_OVF_INT] = "Write FIFO over flow error",
333 	[ERR_RFIFO_OVF_INT] = "Read FIFO over flow error",
334 	[ERR_WR_TIMEO_INT] = "Write time out error",
335 	[ERR_RD_TIMEO_INT] = "Read time out error",
336 	[ERR_WR_ERR_INT] = "HBF bus write error",
337 	[ERR_RD_ERR_INT] = "HBF bus read error",
338 	[ERR_BAD_DESC_INT] = "Ring descriptor HE0 not set error",
339 	[ERR_DESC_DST_INT] = "HFB reading dst link address error",
340 	[ERR_DESC_SRC_INT] = "HFB reading src link address error",
341 };
342 
343 static bool is_pq_enabled(struct xgene_dma *pdma)
344 {
345 	u32 val;
346 
347 	val = ioread32(pdma->csr_efuse + XGENE_SOC_JTAG1_SHADOW);
348 	return !(val & XGENE_DMA_PQ_DISABLE_MASK);
349 }
350 
351 static u64 xgene_dma_encode_len(size_t len)
352 {
353 	return (len < XGENE_DMA_MAX_BYTE_CNT) ?
354 		((u64)len << XGENE_DMA_DESC_BUFLEN_POS) :
355 		XGENE_DMA_16K_BUFFER_LEN_CODE;
356 }
357 
358 static u8 xgene_dma_encode_xor_flyby(u32 src_cnt)
359 {
360 	static u8 flyby_type[] = {
361 		FLYBY_2SRC_XOR, /* Dummy */
362 		FLYBY_2SRC_XOR, /* Dummy */
363 		FLYBY_2SRC_XOR,
364 		FLYBY_3SRC_XOR,
365 		FLYBY_4SRC_XOR,
366 		FLYBY_5SRC_XOR
367 	};
368 
369 	return flyby_type[src_cnt];
370 }
371 
372 static void xgene_dma_set_src_buffer(__le64 *ext8, size_t *len,
373 				     dma_addr_t *paddr)
374 {
375 	size_t nbytes = (*len < XGENE_DMA_MAX_BYTE_CNT) ?
376 			*len : XGENE_DMA_MAX_BYTE_CNT;
377 
378 	*ext8 |= cpu_to_le64(*paddr);
379 	*ext8 |= cpu_to_le64(xgene_dma_encode_len(nbytes));
380 	*len -= nbytes;
381 	*paddr += nbytes;
382 }
383 
384 static __le64 *xgene_dma_lookup_ext8(struct xgene_dma_desc_hw *desc, int idx)
385 {
386 	switch (idx) {
387 	case 0:
388 		return &desc->m1;
389 	case 1:
390 		return &desc->m0;
391 	case 2:
392 		return &desc->m3;
393 	case 3:
394 		return &desc->m2;
395 	default:
396 		pr_err("Invalid dma descriptor index\n");
397 	}
398 
399 	return NULL;
400 }
401 
402 static void xgene_dma_init_desc(struct xgene_dma_desc_hw *desc,
403 				u16 dst_ring_num)
404 {
405 	desc->m0 |= cpu_to_le64(XGENE_DMA_DESC_IN_BIT);
406 	desc->m0 |= cpu_to_le64((u64)XGENE_DMA_RING_OWNER_DMA <<
407 				XGENE_DMA_DESC_RTYPE_POS);
408 	desc->m1 |= cpu_to_le64(XGENE_DMA_DESC_C_BIT);
409 	desc->m3 |= cpu_to_le64((u64)dst_ring_num <<
410 				XGENE_DMA_DESC_HOENQ_NUM_POS);
411 }
412 
413 static void xgene_dma_prep_xor_desc(struct xgene_dma_chan *chan,
414 				    struct xgene_dma_desc_sw *desc_sw,
415 				    dma_addr_t *dst, dma_addr_t *src,
416 				    u32 src_cnt, size_t *nbytes,
417 				    const u8 *scf)
418 {
419 	struct xgene_dma_desc_hw *desc1, *desc2;
420 	size_t len = *nbytes;
421 	int i;
422 
423 	desc1 = &desc_sw->desc1;
424 	desc2 = &desc_sw->desc2;
425 
426 	/* Initialize DMA descriptor */
427 	xgene_dma_init_desc(desc1, chan->tx_ring.dst_ring_num);
428 
429 	/* Set destination address */
430 	desc1->m2 |= cpu_to_le64(XGENE_DMA_DESC_DR_BIT);
431 	desc1->m3 |= cpu_to_le64(*dst);
432 
433 	/* We have multiple source addresses, so need to set NV bit*/
434 	desc1->m0 |= cpu_to_le64(XGENE_DMA_DESC_NV_BIT);
435 
436 	/* Set flyby opcode */
437 	desc1->m2 |= cpu_to_le64(xgene_dma_encode_xor_flyby(src_cnt));
438 
439 	/* Set 1st to 5th source addresses */
440 	for (i = 0; i < src_cnt; i++) {
441 		len = *nbytes;
442 		xgene_dma_set_src_buffer((i == 0) ? &desc1->m1 :
443 					 xgene_dma_lookup_ext8(desc2, i - 1),
444 					 &len, &src[i]);
445 		desc1->m2 |= cpu_to_le64((scf[i] << ((i + 1) * 8)));
446 	}
447 
448 	/* Update meta data */
449 	*nbytes = len;
450 	*dst += XGENE_DMA_MAX_BYTE_CNT;
451 
452 	/* We need always 64B descriptor to perform xor or pq operations */
453 	desc_sw->flags |= XGENE_DMA_FLAG_64B_DESC;
454 }
455 
456 static dma_cookie_t xgene_dma_tx_submit(struct dma_async_tx_descriptor *tx)
457 {
458 	struct xgene_dma_desc_sw *desc;
459 	struct xgene_dma_chan *chan;
460 	dma_cookie_t cookie;
461 
462 	if (unlikely(!tx))
463 		return -EINVAL;
464 
465 	chan = to_dma_chan(tx->chan);
466 	desc = to_dma_desc_sw(tx);
467 
468 	spin_lock_bh(&chan->lock);
469 
470 	cookie = dma_cookie_assign(tx);
471 
472 	/* Add this transaction list onto the tail of the pending queue */
473 	list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
474 
475 	spin_unlock_bh(&chan->lock);
476 
477 	return cookie;
478 }
479 
480 static void xgene_dma_clean_descriptor(struct xgene_dma_chan *chan,
481 				       struct xgene_dma_desc_sw *desc)
482 {
483 	list_del(&desc->node);
484 	chan_dbg(chan, "LD %p free\n", desc);
485 	dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
486 }
487 
488 static struct xgene_dma_desc_sw *xgene_dma_alloc_descriptor(
489 				 struct xgene_dma_chan *chan)
490 {
491 	struct xgene_dma_desc_sw *desc;
492 	dma_addr_t phys;
493 
494 	desc = dma_pool_zalloc(chan->desc_pool, GFP_NOWAIT, &phys);
495 	if (!desc) {
496 		chan_err(chan, "Failed to allocate LDs\n");
497 		return NULL;
498 	}
499 
500 	INIT_LIST_HEAD(&desc->tx_list);
501 	desc->tx.phys = phys;
502 	desc->tx.tx_submit = xgene_dma_tx_submit;
503 	dma_async_tx_descriptor_init(&desc->tx, &chan->dma_chan);
504 
505 	chan_dbg(chan, "LD %p allocated\n", desc);
506 
507 	return desc;
508 }
509 
510 /**
511  * xgene_dma_clean_completed_descriptor - free all descriptors which
512  * has been completed and acked
513  * @chan: X-Gene DMA channel
514  *
515  * This function is used on all completed and acked descriptors.
516  */
517 static void xgene_dma_clean_completed_descriptor(struct xgene_dma_chan *chan)
518 {
519 	struct xgene_dma_desc_sw *desc, *_desc;
520 
521 	/* Run the callback for each descriptor, in order */
522 	list_for_each_entry_safe(desc, _desc, &chan->ld_completed, node) {
523 		if (async_tx_test_ack(&desc->tx))
524 			xgene_dma_clean_descriptor(chan, desc);
525 	}
526 }
527 
528 /**
529  * xgene_dma_run_tx_complete_actions - cleanup a single link descriptor
530  * @chan: X-Gene DMA channel
531  * @desc: descriptor to cleanup and free
532  *
533  * This function is used on a descriptor which has been executed by the DMA
534  * controller. It will run any callbacks, submit any dependencies.
535  */
536 static void xgene_dma_run_tx_complete_actions(struct xgene_dma_chan *chan,
537 					      struct xgene_dma_desc_sw *desc)
538 {
539 	struct dma_async_tx_descriptor *tx = &desc->tx;
540 
541 	/*
542 	 * If this is not the last transaction in the group,
543 	 * then no need to complete cookie and run any callback as
544 	 * this is not the tx_descriptor which had been sent to caller
545 	 * of this DMA request
546 	 */
547 
548 	if (tx->cookie == 0)
549 		return;
550 
551 	dma_cookie_complete(tx);
552 	dma_descriptor_unmap(tx);
553 
554 	/* Run the link descriptor callback function */
555 	dmaengine_desc_get_callback_invoke(tx, NULL);
556 
557 	/* Run any dependencies */
558 	dma_run_dependencies(tx);
559 }
560 
561 /**
562  * xgene_dma_clean_running_descriptor - move the completed descriptor from
563  * ld_running to ld_completed
564  * @chan: X-Gene DMA channel
565  * @desc: the descriptor which is completed
566  *
567  * Free the descriptor directly if acked by async_tx api,
568  * else move it to queue ld_completed.
569  */
570 static void xgene_dma_clean_running_descriptor(struct xgene_dma_chan *chan,
571 					       struct xgene_dma_desc_sw *desc)
572 {
573 	/* Remove from the list of running transactions */
574 	list_del(&desc->node);
575 
576 	/*
577 	 * the client is allowed to attach dependent operations
578 	 * until 'ack' is set
579 	 */
580 	if (!async_tx_test_ack(&desc->tx)) {
581 		/*
582 		 * Move this descriptor to the list of descriptors which is
583 		 * completed, but still awaiting the 'ack' bit to be set.
584 		 */
585 		list_add_tail(&desc->node, &chan->ld_completed);
586 		return;
587 	}
588 
589 	chan_dbg(chan, "LD %p free\n", desc);
590 	dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
591 }
592 
593 static void xgene_chan_xfer_request(struct xgene_dma_chan *chan,
594 				    struct xgene_dma_desc_sw *desc_sw)
595 {
596 	struct xgene_dma_ring *ring = &chan->tx_ring;
597 	struct xgene_dma_desc_hw *desc_hw;
598 
599 	/* Get hw descriptor from DMA tx ring */
600 	desc_hw = &ring->desc_hw[ring->head];
601 
602 	/*
603 	 * Increment the head count to point next
604 	 * descriptor for next time
605 	 */
606 	if (++ring->head == ring->slots)
607 		ring->head = 0;
608 
609 	/* Copy prepared sw descriptor data to hw descriptor */
610 	memcpy(desc_hw, &desc_sw->desc1, sizeof(*desc_hw));
611 
612 	/*
613 	 * Check if we have prepared 64B descriptor,
614 	 * in this case we need one more hw descriptor
615 	 */
616 	if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) {
617 		desc_hw = &ring->desc_hw[ring->head];
618 
619 		if (++ring->head == ring->slots)
620 			ring->head = 0;
621 
622 		memcpy(desc_hw, &desc_sw->desc2, sizeof(*desc_hw));
623 	}
624 
625 	/* Increment the pending transaction count */
626 	chan->pending += ((desc_sw->flags &
627 			  XGENE_DMA_FLAG_64B_DESC) ? 2 : 1);
628 
629 	/* Notify the hw that we have descriptor ready for execution */
630 	iowrite32((desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) ?
631 		  2 : 1, ring->cmd);
632 }
633 
634 /**
635  * xgene_chan_xfer_ld_pending - push any pending transactions to hw
636  * @chan : X-Gene DMA channel
637  *
638  * LOCKING: must hold chan->lock
639  */
640 static void xgene_chan_xfer_ld_pending(struct xgene_dma_chan *chan)
641 {
642 	struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
643 
644 	/*
645 	 * If the list of pending descriptors is empty, then we
646 	 * don't need to do any work at all
647 	 */
648 	if (list_empty(&chan->ld_pending)) {
649 		chan_dbg(chan, "No pending LDs\n");
650 		return;
651 	}
652 
653 	/*
654 	 * Move elements from the queue of pending transactions onto the list
655 	 * of running transactions and push it to hw for further executions
656 	 */
657 	list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_pending, node) {
658 		/*
659 		 * Check if have pushed max number of transactions to hw
660 		 * as capable, so let's stop here and will push remaining
661 		 * elements from pening ld queue after completing some
662 		 * descriptors that we have already pushed
663 		 */
664 		if (chan->pending >= chan->max_outstanding)
665 			return;
666 
667 		xgene_chan_xfer_request(chan, desc_sw);
668 
669 		/*
670 		 * Delete this element from ld pending queue and append it to
671 		 * ld running queue
672 		 */
673 		list_move_tail(&desc_sw->node, &chan->ld_running);
674 	}
675 }
676 
677 /**
678  * xgene_dma_cleanup_descriptors - cleanup link descriptors which are completed
679  * and move them to ld_completed to free until flag 'ack' is set
680  * @chan: X-Gene DMA channel
681  *
682  * This function is used on descriptors which have been executed by the DMA
683  * controller. It will run any callbacks, submit any dependencies, then
684  * free these descriptors if flag 'ack' is set.
685  */
686 static void xgene_dma_cleanup_descriptors(struct xgene_dma_chan *chan)
687 {
688 	struct xgene_dma_ring *ring = &chan->rx_ring;
689 	struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
690 	struct xgene_dma_desc_hw *desc_hw;
691 	struct list_head ld_completed;
692 	u8 status;
693 
694 	INIT_LIST_HEAD(&ld_completed);
695 
696 	spin_lock(&chan->lock);
697 
698 	/* Clean already completed and acked descriptors */
699 	xgene_dma_clean_completed_descriptor(chan);
700 
701 	/* Move all completed descriptors to ld completed queue, in order */
702 	list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_running, node) {
703 		/* Get subsequent hw descriptor from DMA rx ring */
704 		desc_hw = &ring->desc_hw[ring->head];
705 
706 		/* Check if this descriptor has been completed */
707 		if (unlikely(le64_to_cpu(desc_hw->m0) ==
708 			     XGENE_DMA_DESC_EMPTY_SIGNATURE))
709 			break;
710 
711 		if (++ring->head == ring->slots)
712 			ring->head = 0;
713 
714 		/* Check if we have any error with DMA transactions */
715 		status = XGENE_DMA_DESC_STATUS(
716 				XGENE_DMA_DESC_ELERR_RD(le64_to_cpu(
717 							desc_hw->m0)),
718 				XGENE_DMA_DESC_LERR_RD(le64_to_cpu(
719 						       desc_hw->m0)));
720 		if (status) {
721 			/* Print the DMA error type */
722 			chan_err(chan, "%s\n", xgene_dma_desc_err[status]);
723 
724 			/*
725 			 * We have DMA transactions error here. Dump DMA Tx
726 			 * and Rx descriptors for this request */
727 			XGENE_DMA_DESC_DUMP(&desc_sw->desc1,
728 					    "X-Gene DMA TX DESC1: ");
729 
730 			if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC)
731 				XGENE_DMA_DESC_DUMP(&desc_sw->desc2,
732 						    "X-Gene DMA TX DESC2: ");
733 
734 			XGENE_DMA_DESC_DUMP(desc_hw,
735 					    "X-Gene DMA RX ERR DESC: ");
736 		}
737 
738 		/* Notify the hw about this completed descriptor */
739 		iowrite32(-1, ring->cmd);
740 
741 		/* Mark this hw descriptor as processed */
742 		desc_hw->m0 = cpu_to_le64(XGENE_DMA_DESC_EMPTY_SIGNATURE);
743 
744 		/*
745 		 * Decrement the pending transaction count
746 		 * as we have processed one
747 		 */
748 		chan->pending -= ((desc_sw->flags &
749 				  XGENE_DMA_FLAG_64B_DESC) ? 2 : 1);
750 
751 		/*
752 		 * Delete this node from ld running queue and append it to
753 		 * ld completed queue for further processing
754 		 */
755 		list_move_tail(&desc_sw->node, &ld_completed);
756 	}
757 
758 	/*
759 	 * Start any pending transactions automatically
760 	 * In the ideal case, we keep the DMA controller busy while we go
761 	 * ahead and free the descriptors below.
762 	 */
763 	xgene_chan_xfer_ld_pending(chan);
764 
765 	spin_unlock(&chan->lock);
766 
767 	/* Run the callback for each descriptor, in order */
768 	list_for_each_entry_safe(desc_sw, _desc_sw, &ld_completed, node) {
769 		xgene_dma_run_tx_complete_actions(chan, desc_sw);
770 		xgene_dma_clean_running_descriptor(chan, desc_sw);
771 	}
772 }
773 
774 static int xgene_dma_alloc_chan_resources(struct dma_chan *dchan)
775 {
776 	struct xgene_dma_chan *chan = to_dma_chan(dchan);
777 
778 	/* Has this channel already been allocated? */
779 	if (chan->desc_pool)
780 		return 1;
781 
782 	chan->desc_pool = dma_pool_create(chan->name, chan->dev,
783 					  sizeof(struct xgene_dma_desc_sw),
784 					  0, 0);
785 	if (!chan->desc_pool) {
786 		chan_err(chan, "Failed to allocate descriptor pool\n");
787 		return -ENOMEM;
788 	}
789 
790 	chan_dbg(chan, "Allocate descriptor pool\n");
791 
792 	return 1;
793 }
794 
795 /**
796  * xgene_dma_free_desc_list - Free all descriptors in a queue
797  * @chan: X-Gene DMA channel
798  * @list: the list to free
799  *
800  * LOCKING: must hold chan->lock
801  */
802 static void xgene_dma_free_desc_list(struct xgene_dma_chan *chan,
803 				     struct list_head *list)
804 {
805 	struct xgene_dma_desc_sw *desc, *_desc;
806 
807 	list_for_each_entry_safe(desc, _desc, list, node)
808 		xgene_dma_clean_descriptor(chan, desc);
809 }
810 
811 static void xgene_dma_free_chan_resources(struct dma_chan *dchan)
812 {
813 	struct xgene_dma_chan *chan = to_dma_chan(dchan);
814 
815 	chan_dbg(chan, "Free all resources\n");
816 
817 	if (!chan->desc_pool)
818 		return;
819 
820 	/* Process all running descriptor */
821 	xgene_dma_cleanup_descriptors(chan);
822 
823 	spin_lock_bh(&chan->lock);
824 
825 	/* Clean all link descriptor queues */
826 	xgene_dma_free_desc_list(chan, &chan->ld_pending);
827 	xgene_dma_free_desc_list(chan, &chan->ld_running);
828 	xgene_dma_free_desc_list(chan, &chan->ld_completed);
829 
830 	spin_unlock_bh(&chan->lock);
831 
832 	/* Delete this channel DMA pool */
833 	dma_pool_destroy(chan->desc_pool);
834 	chan->desc_pool = NULL;
835 }
836 
837 static struct dma_async_tx_descriptor *xgene_dma_prep_xor(
838 	struct dma_chan *dchan, dma_addr_t dst,	dma_addr_t *src,
839 	u32 src_cnt, size_t len, unsigned long flags)
840 {
841 	struct xgene_dma_desc_sw *first = NULL, *new;
842 	struct xgene_dma_chan *chan;
843 	static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {
844 				0x01, 0x01, 0x01, 0x01, 0x01};
845 
846 	if (unlikely(!dchan || !len))
847 		return NULL;
848 
849 	chan = to_dma_chan(dchan);
850 
851 	do {
852 		/* Allocate the link descriptor from DMA pool */
853 		new = xgene_dma_alloc_descriptor(chan);
854 		if (!new)
855 			goto fail;
856 
857 		/* Prepare xor DMA descriptor */
858 		xgene_dma_prep_xor_desc(chan, new, &dst, src,
859 					src_cnt, &len, multi);
860 
861 		if (!first)
862 			first = new;
863 
864 		new->tx.cookie = 0;
865 		async_tx_ack(&new->tx);
866 
867 		/* Insert the link descriptor to the LD ring */
868 		list_add_tail(&new->node, &first->tx_list);
869 	} while (len);
870 
871 	new->tx.flags = flags; /* client is in control of this ack */
872 	new->tx.cookie = -EBUSY;
873 	list_splice(&first->tx_list, &new->tx_list);
874 
875 	return &new->tx;
876 
877 fail:
878 	if (!first)
879 		return NULL;
880 
881 	xgene_dma_free_desc_list(chan, &first->tx_list);
882 	return NULL;
883 }
884 
885 static struct dma_async_tx_descriptor *xgene_dma_prep_pq(
886 	struct dma_chan *dchan, dma_addr_t *dst, dma_addr_t *src,
887 	u32 src_cnt, const u8 *scf, size_t len, unsigned long flags)
888 {
889 	struct xgene_dma_desc_sw *first = NULL, *new;
890 	struct xgene_dma_chan *chan;
891 	size_t _len = len;
892 	dma_addr_t _src[XGENE_DMA_MAX_XOR_SRC];
893 	static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {0x01, 0x01, 0x01, 0x01, 0x01};
894 
895 	if (unlikely(!dchan || !len))
896 		return NULL;
897 
898 	chan = to_dma_chan(dchan);
899 
900 	/*
901 	 * Save source addresses on local variable, may be we have to
902 	 * prepare two descriptor to generate P and Q if both enabled
903 	 * in the flags by client
904 	 */
905 	memcpy(_src, src, sizeof(*src) * src_cnt);
906 
907 	if (flags & DMA_PREP_PQ_DISABLE_P)
908 		len = 0;
909 
910 	if (flags & DMA_PREP_PQ_DISABLE_Q)
911 		_len = 0;
912 
913 	do {
914 		/* Allocate the link descriptor from DMA pool */
915 		new = xgene_dma_alloc_descriptor(chan);
916 		if (!new)
917 			goto fail;
918 
919 		if (!first)
920 			first = new;
921 
922 		new->tx.cookie = 0;
923 		async_tx_ack(&new->tx);
924 
925 		/* Insert the link descriptor to the LD ring */
926 		list_add_tail(&new->node, &first->tx_list);
927 
928 		/*
929 		 * Prepare DMA descriptor to generate P,
930 		 * if DMA_PREP_PQ_DISABLE_P flag is not set
931 		 */
932 		if (len) {
933 			xgene_dma_prep_xor_desc(chan, new, &dst[0], src,
934 						src_cnt, &len, multi);
935 			continue;
936 		}
937 
938 		/*
939 		 * Prepare DMA descriptor to generate Q,
940 		 * if DMA_PREP_PQ_DISABLE_Q flag is not set
941 		 */
942 		if (_len) {
943 			xgene_dma_prep_xor_desc(chan, new, &dst[1], _src,
944 						src_cnt, &_len, scf);
945 		}
946 	} while (len || _len);
947 
948 	new->tx.flags = flags; /* client is in control of this ack */
949 	new->tx.cookie = -EBUSY;
950 	list_splice(&first->tx_list, &new->tx_list);
951 
952 	return &new->tx;
953 
954 fail:
955 	if (!first)
956 		return NULL;
957 
958 	xgene_dma_free_desc_list(chan, &first->tx_list);
959 	return NULL;
960 }
961 
962 static void xgene_dma_issue_pending(struct dma_chan *dchan)
963 {
964 	struct xgene_dma_chan *chan = to_dma_chan(dchan);
965 
966 	spin_lock_bh(&chan->lock);
967 	xgene_chan_xfer_ld_pending(chan);
968 	spin_unlock_bh(&chan->lock);
969 }
970 
971 static enum dma_status xgene_dma_tx_status(struct dma_chan *dchan,
972 					   dma_cookie_t cookie,
973 					   struct dma_tx_state *txstate)
974 {
975 	return dma_cookie_status(dchan, cookie, txstate);
976 }
977 
978 static void xgene_dma_tasklet_cb(struct tasklet_struct *t)
979 {
980 	struct xgene_dma_chan *chan = from_tasklet(chan, t, tasklet);
981 
982 	/* Run all cleanup for descriptors which have been completed */
983 	xgene_dma_cleanup_descriptors(chan);
984 
985 	/* Re-enable DMA channel IRQ */
986 	enable_irq(chan->rx_irq);
987 }
988 
989 static irqreturn_t xgene_dma_chan_ring_isr(int irq, void *id)
990 {
991 	struct xgene_dma_chan *chan = (struct xgene_dma_chan *)id;
992 
993 	BUG_ON(!chan);
994 
995 	/*
996 	 * Disable DMA channel IRQ until we process completed
997 	 * descriptors
998 	 */
999 	disable_irq_nosync(chan->rx_irq);
1000 
1001 	/*
1002 	 * Schedule the tasklet to handle all cleanup of the current
1003 	 * transaction. It will start a new transaction if there is
1004 	 * one pending.
1005 	 */
1006 	tasklet_schedule(&chan->tasklet);
1007 
1008 	return IRQ_HANDLED;
1009 }
1010 
1011 static irqreturn_t xgene_dma_err_isr(int irq, void *id)
1012 {
1013 	struct xgene_dma *pdma = (struct xgene_dma *)id;
1014 	unsigned long int_mask;
1015 	u32 val, i;
1016 
1017 	val = ioread32(pdma->csr_dma + XGENE_DMA_INT);
1018 
1019 	/* Clear DMA interrupts */
1020 	iowrite32(val, pdma->csr_dma + XGENE_DMA_INT);
1021 
1022 	/* Print DMA error info */
1023 	int_mask = val >> XGENE_DMA_INT_MASK_SHIFT;
1024 	for_each_set_bit(i, &int_mask, ARRAY_SIZE(xgene_dma_err))
1025 		dev_err(pdma->dev,
1026 			"Interrupt status 0x%08X %s\n", val, xgene_dma_err[i]);
1027 
1028 	return IRQ_HANDLED;
1029 }
1030 
1031 static void xgene_dma_wr_ring_state(struct xgene_dma_ring *ring)
1032 {
1033 	int i;
1034 
1035 	iowrite32(ring->num, ring->pdma->csr_ring + XGENE_DMA_RING_STATE);
1036 
1037 	for (i = 0; i < XGENE_DMA_RING_NUM_CONFIG; i++)
1038 		iowrite32(ring->state[i], ring->pdma->csr_ring +
1039 			  XGENE_DMA_RING_STATE_WR_BASE + (i * 4));
1040 }
1041 
1042 static void xgene_dma_clr_ring_state(struct xgene_dma_ring *ring)
1043 {
1044 	memset(ring->state, 0, sizeof(u32) * XGENE_DMA_RING_NUM_CONFIG);
1045 	xgene_dma_wr_ring_state(ring);
1046 }
1047 
1048 static void xgene_dma_setup_ring(struct xgene_dma_ring *ring)
1049 {
1050 	void *ring_cfg = ring->state;
1051 	u64 addr = ring->desc_paddr;
1052 	u32 i, val;
1053 
1054 	ring->slots = ring->size / XGENE_DMA_RING_WQ_DESC_SIZE;
1055 
1056 	/* Clear DMA ring state */
1057 	xgene_dma_clr_ring_state(ring);
1058 
1059 	/* Set DMA ring type */
1060 	XGENE_DMA_RING_TYPE_SET(ring_cfg, XGENE_DMA_RING_TYPE_REGULAR);
1061 
1062 	if (ring->owner == XGENE_DMA_RING_OWNER_DMA) {
1063 		/* Set recombination buffer and timeout */
1064 		XGENE_DMA_RING_RECOMBBUF_SET(ring_cfg);
1065 		XGENE_DMA_RING_RECOMTIMEOUTL_SET(ring_cfg);
1066 		XGENE_DMA_RING_RECOMTIMEOUTH_SET(ring_cfg);
1067 	}
1068 
1069 	/* Initialize DMA ring state */
1070 	XGENE_DMA_RING_SELTHRSH_SET(ring_cfg);
1071 	XGENE_DMA_RING_ACCEPTLERR_SET(ring_cfg);
1072 	XGENE_DMA_RING_COHERENT_SET(ring_cfg);
1073 	XGENE_DMA_RING_ADDRL_SET(ring_cfg, addr);
1074 	XGENE_DMA_RING_ADDRH_SET(ring_cfg, addr);
1075 	XGENE_DMA_RING_SIZE_SET(ring_cfg, ring->cfgsize);
1076 
1077 	/* Write DMA ring configurations */
1078 	xgene_dma_wr_ring_state(ring);
1079 
1080 	/* Set DMA ring id */
1081 	iowrite32(XGENE_DMA_RING_ID_SETUP(ring->id),
1082 		  ring->pdma->csr_ring + XGENE_DMA_RING_ID);
1083 
1084 	/* Set DMA ring buffer */
1085 	iowrite32(XGENE_DMA_RING_ID_BUF_SETUP(ring->num),
1086 		  ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
1087 
1088 	if (ring->owner != XGENE_DMA_RING_OWNER_CPU)
1089 		return;
1090 
1091 	/* Set empty signature to DMA Rx ring descriptors */
1092 	for (i = 0; i < ring->slots; i++) {
1093 		struct xgene_dma_desc_hw *desc;
1094 
1095 		desc = &ring->desc_hw[i];
1096 		desc->m0 = cpu_to_le64(XGENE_DMA_DESC_EMPTY_SIGNATURE);
1097 	}
1098 
1099 	/* Enable DMA Rx ring interrupt */
1100 	val = ioread32(ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
1101 	XGENE_DMA_RING_NE_INT_MODE_SET(val, ring->buf_num);
1102 	iowrite32(val, ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
1103 }
1104 
1105 static void xgene_dma_clear_ring(struct xgene_dma_ring *ring)
1106 {
1107 	u32 ring_id, val;
1108 
1109 	if (ring->owner == XGENE_DMA_RING_OWNER_CPU) {
1110 		/* Disable DMA Rx ring interrupt */
1111 		val = ioread32(ring->pdma->csr_ring +
1112 			       XGENE_DMA_RING_NE_INT_MODE);
1113 		XGENE_DMA_RING_NE_INT_MODE_RESET(val, ring->buf_num);
1114 		iowrite32(val, ring->pdma->csr_ring +
1115 			  XGENE_DMA_RING_NE_INT_MODE);
1116 	}
1117 
1118 	/* Clear DMA ring state */
1119 	ring_id = XGENE_DMA_RING_ID_SETUP(ring->id);
1120 	iowrite32(ring_id, ring->pdma->csr_ring + XGENE_DMA_RING_ID);
1121 
1122 	iowrite32(0, ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
1123 	xgene_dma_clr_ring_state(ring);
1124 }
1125 
1126 static void xgene_dma_set_ring_cmd(struct xgene_dma_ring *ring)
1127 {
1128 	ring->cmd_base = ring->pdma->csr_ring_cmd +
1129 				XGENE_DMA_RING_CMD_BASE_OFFSET((ring->num -
1130 							  XGENE_DMA_RING_NUM));
1131 
1132 	ring->cmd = ring->cmd_base + XGENE_DMA_RING_CMD_OFFSET;
1133 }
1134 
1135 static int xgene_dma_get_ring_size(struct xgene_dma_chan *chan,
1136 				   enum xgene_dma_ring_cfgsize cfgsize)
1137 {
1138 	int size;
1139 
1140 	switch (cfgsize) {
1141 	case XGENE_DMA_RING_CFG_SIZE_512B:
1142 		size = 0x200;
1143 		break;
1144 	case XGENE_DMA_RING_CFG_SIZE_2KB:
1145 		size = 0x800;
1146 		break;
1147 	case XGENE_DMA_RING_CFG_SIZE_16KB:
1148 		size = 0x4000;
1149 		break;
1150 	case XGENE_DMA_RING_CFG_SIZE_64KB:
1151 		size = 0x10000;
1152 		break;
1153 	case XGENE_DMA_RING_CFG_SIZE_512KB:
1154 		size = 0x80000;
1155 		break;
1156 	default:
1157 		chan_err(chan, "Unsupported cfg ring size %d\n", cfgsize);
1158 		return -EINVAL;
1159 	}
1160 
1161 	return size;
1162 }
1163 
1164 static void xgene_dma_delete_ring_one(struct xgene_dma_ring *ring)
1165 {
1166 	/* Clear DMA ring configurations */
1167 	xgene_dma_clear_ring(ring);
1168 
1169 	/* De-allocate DMA ring descriptor */
1170 	if (ring->desc_vaddr) {
1171 		dma_free_coherent(ring->pdma->dev, ring->size,
1172 				  ring->desc_vaddr, ring->desc_paddr);
1173 		ring->desc_vaddr = NULL;
1174 	}
1175 }
1176 
1177 static void xgene_dma_delete_chan_rings(struct xgene_dma_chan *chan)
1178 {
1179 	xgene_dma_delete_ring_one(&chan->rx_ring);
1180 	xgene_dma_delete_ring_one(&chan->tx_ring);
1181 }
1182 
1183 static int xgene_dma_create_ring_one(struct xgene_dma_chan *chan,
1184 				     struct xgene_dma_ring *ring,
1185 				     enum xgene_dma_ring_cfgsize cfgsize)
1186 {
1187 	int ret;
1188 
1189 	/* Setup DMA ring descriptor variables */
1190 	ring->pdma = chan->pdma;
1191 	ring->cfgsize = cfgsize;
1192 	ring->num = chan->pdma->ring_num++;
1193 	ring->id = XGENE_DMA_RING_ID_GET(ring->owner, ring->buf_num);
1194 
1195 	ret = xgene_dma_get_ring_size(chan, cfgsize);
1196 	if (ret <= 0)
1197 		return ret;
1198 	ring->size = ret;
1199 
1200 	/* Allocate memory for DMA ring descriptor */
1201 	ring->desc_vaddr = dma_alloc_coherent(chan->dev, ring->size,
1202 					      &ring->desc_paddr, GFP_KERNEL);
1203 	if (!ring->desc_vaddr) {
1204 		chan_err(chan, "Failed to allocate ring desc\n");
1205 		return -ENOMEM;
1206 	}
1207 
1208 	/* Configure and enable DMA ring */
1209 	xgene_dma_set_ring_cmd(ring);
1210 	xgene_dma_setup_ring(ring);
1211 
1212 	return 0;
1213 }
1214 
1215 static int xgene_dma_create_chan_rings(struct xgene_dma_chan *chan)
1216 {
1217 	struct xgene_dma_ring *rx_ring = &chan->rx_ring;
1218 	struct xgene_dma_ring *tx_ring = &chan->tx_ring;
1219 	int ret;
1220 
1221 	/* Create DMA Rx ring descriptor */
1222 	rx_ring->owner = XGENE_DMA_RING_OWNER_CPU;
1223 	rx_ring->buf_num = XGENE_DMA_CPU_BUFNUM + chan->id;
1224 
1225 	ret = xgene_dma_create_ring_one(chan, rx_ring,
1226 					XGENE_DMA_RING_CFG_SIZE_64KB);
1227 	if (ret)
1228 		return ret;
1229 
1230 	chan_dbg(chan, "Rx ring id 0x%X num %d desc 0x%p\n",
1231 		 rx_ring->id, rx_ring->num, rx_ring->desc_vaddr);
1232 
1233 	/* Create DMA Tx ring descriptor */
1234 	tx_ring->owner = XGENE_DMA_RING_OWNER_DMA;
1235 	tx_ring->buf_num = XGENE_DMA_BUFNUM + chan->id;
1236 
1237 	ret = xgene_dma_create_ring_one(chan, tx_ring,
1238 					XGENE_DMA_RING_CFG_SIZE_64KB);
1239 	if (ret) {
1240 		xgene_dma_delete_ring_one(rx_ring);
1241 		return ret;
1242 	}
1243 
1244 	tx_ring->dst_ring_num = XGENE_DMA_RING_DST_ID(rx_ring->num);
1245 
1246 	chan_dbg(chan,
1247 		 "Tx ring id 0x%X num %d desc 0x%p\n",
1248 		 tx_ring->id, tx_ring->num, tx_ring->desc_vaddr);
1249 
1250 	/* Set the max outstanding request possible to this channel */
1251 	chan->max_outstanding = tx_ring->slots;
1252 
1253 	return ret;
1254 }
1255 
1256 static int xgene_dma_init_rings(struct xgene_dma *pdma)
1257 {
1258 	int ret, i, j;
1259 
1260 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1261 		ret = xgene_dma_create_chan_rings(&pdma->chan[i]);
1262 		if (ret) {
1263 			for (j = 0; j < i; j++)
1264 				xgene_dma_delete_chan_rings(&pdma->chan[j]);
1265 			return ret;
1266 		}
1267 	}
1268 
1269 	return ret;
1270 }
1271 
1272 static void xgene_dma_enable(struct xgene_dma *pdma)
1273 {
1274 	u32 val;
1275 
1276 	/* Configure and enable DMA engine */
1277 	val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
1278 	XGENE_DMA_CH_SETUP(val);
1279 	XGENE_DMA_ENABLE(val);
1280 	iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
1281 }
1282 
1283 static void xgene_dma_disable(struct xgene_dma *pdma)
1284 {
1285 	u32 val;
1286 
1287 	val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
1288 	XGENE_DMA_DISABLE(val);
1289 	iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
1290 }
1291 
1292 static void xgene_dma_mask_interrupts(struct xgene_dma *pdma)
1293 {
1294 	/*
1295 	 * Mask DMA ring overflow, underflow and
1296 	 * AXI write/read error interrupts
1297 	 */
1298 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1299 		  pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
1300 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1301 		  pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
1302 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1303 		  pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
1304 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1305 		  pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
1306 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1307 		  pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
1308 
1309 	/* Mask DMA error interrupts */
1310 	iowrite32(XGENE_DMA_INT_ALL_MASK, pdma->csr_dma + XGENE_DMA_INT_MASK);
1311 }
1312 
1313 static void xgene_dma_unmask_interrupts(struct xgene_dma *pdma)
1314 {
1315 	/*
1316 	 * Unmask DMA ring overflow, underflow and
1317 	 * AXI write/read error interrupts
1318 	 */
1319 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1320 		  pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
1321 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1322 		  pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
1323 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1324 		  pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
1325 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1326 		  pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
1327 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1328 		  pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
1329 
1330 	/* Unmask DMA error interrupts */
1331 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1332 		  pdma->csr_dma + XGENE_DMA_INT_MASK);
1333 }
1334 
1335 static void xgene_dma_init_hw(struct xgene_dma *pdma)
1336 {
1337 	u32 val;
1338 
1339 	/* Associate DMA ring to corresponding ring HW */
1340 	iowrite32(XGENE_DMA_ASSOC_RING_MNGR1,
1341 		  pdma->csr_dma + XGENE_DMA_CFG_RING_WQ_ASSOC);
1342 
1343 	/* Configure RAID6 polynomial control setting */
1344 	if (is_pq_enabled(pdma))
1345 		iowrite32(XGENE_DMA_RAID6_MULTI_CTRL(0x1D),
1346 			  pdma->csr_dma + XGENE_DMA_RAID6_CONT);
1347 	else
1348 		dev_info(pdma->dev, "PQ is disabled in HW\n");
1349 
1350 	xgene_dma_enable(pdma);
1351 	xgene_dma_unmask_interrupts(pdma);
1352 
1353 	/* Get DMA id and version info */
1354 	val = ioread32(pdma->csr_dma + XGENE_DMA_IPBRR);
1355 
1356 	/* DMA device info */
1357 	dev_info(pdma->dev,
1358 		 "X-Gene DMA v%d.%02d.%02d driver registered %d channels",
1359 		 XGENE_DMA_REV_NO_RD(val), XGENE_DMA_BUS_ID_RD(val),
1360 		 XGENE_DMA_DEV_ID_RD(val), XGENE_DMA_MAX_CHANNEL);
1361 }
1362 
1363 static int xgene_dma_init_ring_mngr(struct xgene_dma *pdma)
1364 {
1365 	if (ioread32(pdma->csr_ring + XGENE_DMA_RING_CLKEN) &&
1366 	    (!ioread32(pdma->csr_ring + XGENE_DMA_RING_SRST)))
1367 		return 0;
1368 
1369 	iowrite32(0x3, pdma->csr_ring + XGENE_DMA_RING_CLKEN);
1370 	iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_SRST);
1371 
1372 	/* Bring up memory */
1373 	iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
1374 
1375 	/* Force a barrier */
1376 	ioread32(pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
1377 
1378 	/* reset may take up to 1ms */
1379 	usleep_range(1000, 1100);
1380 
1381 	if (ioread32(pdma->csr_ring + XGENE_DMA_RING_BLK_MEM_RDY)
1382 		!= XGENE_DMA_RING_BLK_MEM_RDY_VAL) {
1383 		dev_err(pdma->dev,
1384 			"Failed to release ring mngr memory from shutdown\n");
1385 		return -ENODEV;
1386 	}
1387 
1388 	/* program threshold set 1 and all hysteresis */
1389 	iowrite32(XGENE_DMA_RING_THRESLD0_SET1_VAL,
1390 		  pdma->csr_ring + XGENE_DMA_RING_THRESLD0_SET1);
1391 	iowrite32(XGENE_DMA_RING_THRESLD1_SET1_VAL,
1392 		  pdma->csr_ring + XGENE_DMA_RING_THRESLD1_SET1);
1393 	iowrite32(XGENE_DMA_RING_HYSTERESIS_VAL,
1394 		  pdma->csr_ring + XGENE_DMA_RING_HYSTERESIS);
1395 
1396 	/* Enable QPcore and assign error queue */
1397 	iowrite32(XGENE_DMA_RING_ENABLE,
1398 		  pdma->csr_ring + XGENE_DMA_RING_CONFIG);
1399 
1400 	return 0;
1401 }
1402 
1403 static int xgene_dma_init_mem(struct xgene_dma *pdma)
1404 {
1405 	int ret;
1406 
1407 	ret = xgene_dma_init_ring_mngr(pdma);
1408 	if (ret)
1409 		return ret;
1410 
1411 	/* Bring up memory */
1412 	iowrite32(0x0, pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
1413 
1414 	/* Force a barrier */
1415 	ioread32(pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
1416 
1417 	/* reset may take up to 1ms */
1418 	usleep_range(1000, 1100);
1419 
1420 	if (ioread32(pdma->csr_dma + XGENE_DMA_BLK_MEM_RDY)
1421 		!= XGENE_DMA_BLK_MEM_RDY_VAL) {
1422 		dev_err(pdma->dev,
1423 			"Failed to release DMA memory from shutdown\n");
1424 		return -ENODEV;
1425 	}
1426 
1427 	return 0;
1428 }
1429 
1430 static int xgene_dma_request_irqs(struct xgene_dma *pdma)
1431 {
1432 	struct xgene_dma_chan *chan;
1433 	int ret, i, j;
1434 
1435 	/* Register DMA error irq */
1436 	ret = devm_request_irq(pdma->dev, pdma->err_irq, xgene_dma_err_isr,
1437 			       0, "dma_error", pdma);
1438 	if (ret) {
1439 		dev_err(pdma->dev,
1440 			"Failed to register error IRQ %d\n", pdma->err_irq);
1441 		return ret;
1442 	}
1443 
1444 	/* Register DMA channel rx irq */
1445 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1446 		chan = &pdma->chan[i];
1447 		irq_set_status_flags(chan->rx_irq, IRQ_DISABLE_UNLAZY);
1448 		ret = devm_request_irq(chan->dev, chan->rx_irq,
1449 				       xgene_dma_chan_ring_isr,
1450 				       0, chan->name, chan);
1451 		if (ret) {
1452 			chan_err(chan, "Failed to register Rx IRQ %d\n",
1453 				 chan->rx_irq);
1454 			devm_free_irq(pdma->dev, pdma->err_irq, pdma);
1455 
1456 			for (j = 0; j < i; j++) {
1457 				chan = &pdma->chan[i];
1458 				irq_clear_status_flags(chan->rx_irq, IRQ_DISABLE_UNLAZY);
1459 				devm_free_irq(chan->dev, chan->rx_irq, chan);
1460 			}
1461 
1462 			return ret;
1463 		}
1464 	}
1465 
1466 	return 0;
1467 }
1468 
1469 static void xgene_dma_free_irqs(struct xgene_dma *pdma)
1470 {
1471 	struct xgene_dma_chan *chan;
1472 	int i;
1473 
1474 	/* Free DMA device error irq */
1475 	devm_free_irq(pdma->dev, pdma->err_irq, pdma);
1476 
1477 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1478 		chan = &pdma->chan[i];
1479 		irq_clear_status_flags(chan->rx_irq, IRQ_DISABLE_UNLAZY);
1480 		devm_free_irq(chan->dev, chan->rx_irq, chan);
1481 	}
1482 }
1483 
1484 static void xgene_dma_set_caps(struct xgene_dma_chan *chan,
1485 			       struct dma_device *dma_dev)
1486 {
1487 	/* Initialize DMA device capability mask */
1488 	dma_cap_zero(dma_dev->cap_mask);
1489 
1490 	/* Set DMA device capability */
1491 
1492 	/* Basically here, the X-Gene SoC DMA engine channel 0 supports XOR
1493 	 * and channel 1 supports XOR, PQ both. First thing here is we have
1494 	 * mechanism in hw to enable/disable PQ/XOR supports on channel 1,
1495 	 * we can make sure this by reading SoC Efuse register.
1496 	 * Second thing, we have hw errata that if we run channel 0 and
1497 	 * channel 1 simultaneously with executing XOR and PQ request,
1498 	 * suddenly DMA engine hangs, So here we enable XOR on channel 0 only
1499 	 * if XOR and PQ supports on channel 1 is disabled.
1500 	 */
1501 	if ((chan->id == XGENE_DMA_PQ_CHANNEL) &&
1502 	    is_pq_enabled(chan->pdma)) {
1503 		dma_cap_set(DMA_PQ, dma_dev->cap_mask);
1504 		dma_cap_set(DMA_XOR, dma_dev->cap_mask);
1505 	} else if ((chan->id == XGENE_DMA_XOR_CHANNEL) &&
1506 		   !is_pq_enabled(chan->pdma)) {
1507 		dma_cap_set(DMA_XOR, dma_dev->cap_mask);
1508 	}
1509 
1510 	/* Set base and prep routines */
1511 	dma_dev->dev = chan->dev;
1512 	dma_dev->device_alloc_chan_resources = xgene_dma_alloc_chan_resources;
1513 	dma_dev->device_free_chan_resources = xgene_dma_free_chan_resources;
1514 	dma_dev->device_issue_pending = xgene_dma_issue_pending;
1515 	dma_dev->device_tx_status = xgene_dma_tx_status;
1516 
1517 	if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
1518 		dma_dev->device_prep_dma_xor = xgene_dma_prep_xor;
1519 		dma_dev->max_xor = XGENE_DMA_MAX_XOR_SRC;
1520 		dma_dev->xor_align = DMAENGINE_ALIGN_64_BYTES;
1521 	}
1522 
1523 	if (dma_has_cap(DMA_PQ, dma_dev->cap_mask)) {
1524 		dma_dev->device_prep_dma_pq = xgene_dma_prep_pq;
1525 		dma_dev->max_pq = XGENE_DMA_MAX_XOR_SRC;
1526 		dma_dev->pq_align = DMAENGINE_ALIGN_64_BYTES;
1527 	}
1528 }
1529 
1530 static int xgene_dma_async_register(struct xgene_dma *pdma, int id)
1531 {
1532 	struct xgene_dma_chan *chan = &pdma->chan[id];
1533 	struct dma_device *dma_dev = &pdma->dma_dev[id];
1534 	int ret;
1535 
1536 	chan->dma_chan.device = dma_dev;
1537 
1538 	spin_lock_init(&chan->lock);
1539 	INIT_LIST_HEAD(&chan->ld_pending);
1540 	INIT_LIST_HEAD(&chan->ld_running);
1541 	INIT_LIST_HEAD(&chan->ld_completed);
1542 	tasklet_setup(&chan->tasklet, xgene_dma_tasklet_cb);
1543 
1544 	chan->pending = 0;
1545 	chan->desc_pool = NULL;
1546 	dma_cookie_init(&chan->dma_chan);
1547 
1548 	/* Setup dma device capabilities and prep routines */
1549 	xgene_dma_set_caps(chan, dma_dev);
1550 
1551 	/* Initialize DMA device list head */
1552 	INIT_LIST_HEAD(&dma_dev->channels);
1553 	list_add_tail(&chan->dma_chan.device_node, &dma_dev->channels);
1554 
1555 	/* Register with Linux async DMA framework*/
1556 	ret = dma_async_device_register(dma_dev);
1557 	if (ret) {
1558 		chan_err(chan, "Failed to register async device %d", ret);
1559 		tasklet_kill(&chan->tasklet);
1560 
1561 		return ret;
1562 	}
1563 
1564 	/* DMA capability info */
1565 	dev_info(pdma->dev,
1566 		 "%s: CAPABILITY ( %s%s)\n", dma_chan_name(&chan->dma_chan),
1567 		 dma_has_cap(DMA_XOR, dma_dev->cap_mask) ? "XOR " : "",
1568 		 dma_has_cap(DMA_PQ, dma_dev->cap_mask) ? "PQ " : "");
1569 
1570 	return 0;
1571 }
1572 
1573 static int xgene_dma_init_async(struct xgene_dma *pdma)
1574 {
1575 	int ret, i, j;
1576 
1577 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL ; i++) {
1578 		ret = xgene_dma_async_register(pdma, i);
1579 		if (ret) {
1580 			for (j = 0; j < i; j++) {
1581 				dma_async_device_unregister(&pdma->dma_dev[j]);
1582 				tasklet_kill(&pdma->chan[j].tasklet);
1583 			}
1584 
1585 			return ret;
1586 		}
1587 	}
1588 
1589 	return ret;
1590 }
1591 
1592 static void xgene_dma_async_unregister(struct xgene_dma *pdma)
1593 {
1594 	int i;
1595 
1596 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
1597 		dma_async_device_unregister(&pdma->dma_dev[i]);
1598 }
1599 
1600 static void xgene_dma_init_channels(struct xgene_dma *pdma)
1601 {
1602 	struct xgene_dma_chan *chan;
1603 	int i;
1604 
1605 	pdma->ring_num = XGENE_DMA_RING_NUM;
1606 
1607 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1608 		chan = &pdma->chan[i];
1609 		chan->dev = pdma->dev;
1610 		chan->pdma = pdma;
1611 		chan->id = i;
1612 		snprintf(chan->name, sizeof(chan->name), "dmachan%d", chan->id);
1613 	}
1614 }
1615 
1616 static int xgene_dma_get_resources(struct platform_device *pdev,
1617 				   struct xgene_dma *pdma)
1618 {
1619 	struct resource *res;
1620 	int irq, i;
1621 
1622 	/* Get DMA csr region */
1623 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1624 	if (!res) {
1625 		dev_err(&pdev->dev, "Failed to get csr region\n");
1626 		return -ENXIO;
1627 	}
1628 
1629 	pdma->csr_dma = devm_ioremap(&pdev->dev, res->start,
1630 				     resource_size(res));
1631 	if (!pdma->csr_dma) {
1632 		dev_err(&pdev->dev, "Failed to ioremap csr region");
1633 		return -ENOMEM;
1634 	}
1635 
1636 	/* Get DMA ring csr region */
1637 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1638 	if (!res) {
1639 		dev_err(&pdev->dev, "Failed to get ring csr region\n");
1640 		return -ENXIO;
1641 	}
1642 
1643 	pdma->csr_ring =  devm_ioremap(&pdev->dev, res->start,
1644 				       resource_size(res));
1645 	if (!pdma->csr_ring) {
1646 		dev_err(&pdev->dev, "Failed to ioremap ring csr region");
1647 		return -ENOMEM;
1648 	}
1649 
1650 	/* Get DMA ring cmd csr region */
1651 	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
1652 	if (!res) {
1653 		dev_err(&pdev->dev, "Failed to get ring cmd csr region\n");
1654 		return -ENXIO;
1655 	}
1656 
1657 	pdma->csr_ring_cmd = devm_ioremap(&pdev->dev, res->start,
1658 					  resource_size(res));
1659 	if (!pdma->csr_ring_cmd) {
1660 		dev_err(&pdev->dev, "Failed to ioremap ring cmd csr region");
1661 		return -ENOMEM;
1662 	}
1663 
1664 	pdma->csr_ring_cmd += XGENE_DMA_RING_CMD_SM_OFFSET;
1665 
1666 	/* Get efuse csr region */
1667 	res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
1668 	if (!res) {
1669 		dev_err(&pdev->dev, "Failed to get efuse csr region\n");
1670 		return -ENXIO;
1671 	}
1672 
1673 	pdma->csr_efuse = devm_ioremap(&pdev->dev, res->start,
1674 				       resource_size(res));
1675 	if (!pdma->csr_efuse) {
1676 		dev_err(&pdev->dev, "Failed to ioremap efuse csr region");
1677 		return -ENOMEM;
1678 	}
1679 
1680 	/* Get DMA error interrupt */
1681 	irq = platform_get_irq(pdev, 0);
1682 	if (irq <= 0)
1683 		return -ENXIO;
1684 
1685 	pdma->err_irq = irq;
1686 
1687 	/* Get DMA Rx ring descriptor interrupts for all DMA channels */
1688 	for (i = 1; i <= XGENE_DMA_MAX_CHANNEL; i++) {
1689 		irq = platform_get_irq(pdev, i);
1690 		if (irq <= 0)
1691 			return -ENXIO;
1692 
1693 		pdma->chan[i - 1].rx_irq = irq;
1694 	}
1695 
1696 	return 0;
1697 }
1698 
1699 static int xgene_dma_probe(struct platform_device *pdev)
1700 {
1701 	struct xgene_dma *pdma;
1702 	int ret, i;
1703 
1704 	pdma = devm_kzalloc(&pdev->dev, sizeof(*pdma), GFP_KERNEL);
1705 	if (!pdma)
1706 		return -ENOMEM;
1707 
1708 	pdma->dev = &pdev->dev;
1709 	platform_set_drvdata(pdev, pdma);
1710 
1711 	ret = xgene_dma_get_resources(pdev, pdma);
1712 	if (ret)
1713 		return ret;
1714 
1715 	pdma->clk = devm_clk_get(&pdev->dev, NULL);
1716 	if (IS_ERR(pdma->clk) && !ACPI_COMPANION(&pdev->dev)) {
1717 		dev_err(&pdev->dev, "Failed to get clk\n");
1718 		return PTR_ERR(pdma->clk);
1719 	}
1720 
1721 	/* Enable clk before accessing registers */
1722 	if (!IS_ERR(pdma->clk)) {
1723 		ret = clk_prepare_enable(pdma->clk);
1724 		if (ret) {
1725 			dev_err(&pdev->dev, "Failed to enable clk %d\n", ret);
1726 			return ret;
1727 		}
1728 	}
1729 
1730 	/* Remove DMA RAM out of shutdown */
1731 	ret = xgene_dma_init_mem(pdma);
1732 	if (ret)
1733 		goto err_clk_enable;
1734 
1735 	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(42));
1736 	if (ret) {
1737 		dev_err(&pdev->dev, "No usable DMA configuration\n");
1738 		goto err_dma_mask;
1739 	}
1740 
1741 	/* Initialize DMA channels software state */
1742 	xgene_dma_init_channels(pdma);
1743 
1744 	/* Configue DMA rings */
1745 	ret = xgene_dma_init_rings(pdma);
1746 	if (ret)
1747 		goto err_clk_enable;
1748 
1749 	ret = xgene_dma_request_irqs(pdma);
1750 	if (ret)
1751 		goto err_request_irq;
1752 
1753 	/* Configure and enable DMA engine */
1754 	xgene_dma_init_hw(pdma);
1755 
1756 	/* Register DMA device with linux async framework */
1757 	ret = xgene_dma_init_async(pdma);
1758 	if (ret)
1759 		goto err_async_init;
1760 
1761 	return 0;
1762 
1763 err_async_init:
1764 	xgene_dma_free_irqs(pdma);
1765 
1766 err_request_irq:
1767 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
1768 		xgene_dma_delete_chan_rings(&pdma->chan[i]);
1769 
1770 err_dma_mask:
1771 err_clk_enable:
1772 	if (!IS_ERR(pdma->clk))
1773 		clk_disable_unprepare(pdma->clk);
1774 
1775 	return ret;
1776 }
1777 
1778 static int xgene_dma_remove(struct platform_device *pdev)
1779 {
1780 	struct xgene_dma *pdma = platform_get_drvdata(pdev);
1781 	struct xgene_dma_chan *chan;
1782 	int i;
1783 
1784 	xgene_dma_async_unregister(pdma);
1785 
1786 	/* Mask interrupts and disable DMA engine */
1787 	xgene_dma_mask_interrupts(pdma);
1788 	xgene_dma_disable(pdma);
1789 	xgene_dma_free_irqs(pdma);
1790 
1791 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1792 		chan = &pdma->chan[i];
1793 		tasklet_kill(&chan->tasklet);
1794 		xgene_dma_delete_chan_rings(chan);
1795 	}
1796 
1797 	if (!IS_ERR(pdma->clk))
1798 		clk_disable_unprepare(pdma->clk);
1799 
1800 	return 0;
1801 }
1802 
1803 #ifdef CONFIG_ACPI
1804 static const struct acpi_device_id xgene_dma_acpi_match_ptr[] = {
1805 	{"APMC0D43", 0},
1806 	{},
1807 };
1808 MODULE_DEVICE_TABLE(acpi, xgene_dma_acpi_match_ptr);
1809 #endif
1810 
1811 static const struct of_device_id xgene_dma_of_match_ptr[] = {
1812 	{.compatible = "apm,xgene-storm-dma",},
1813 	{},
1814 };
1815 MODULE_DEVICE_TABLE(of, xgene_dma_of_match_ptr);
1816 
1817 static struct platform_driver xgene_dma_driver = {
1818 	.probe = xgene_dma_probe,
1819 	.remove = xgene_dma_remove,
1820 	.driver = {
1821 		.name = "X-Gene-DMA",
1822 		.of_match_table = xgene_dma_of_match_ptr,
1823 		.acpi_match_table = ACPI_PTR(xgene_dma_acpi_match_ptr),
1824 	},
1825 };
1826 
1827 module_platform_driver(xgene_dma_driver);
1828 
1829 MODULE_DESCRIPTION("APM X-Gene SoC DMA driver");
1830 MODULE_AUTHOR("Rameshwar Prasad Sahu <rsahu@apm.com>");
1831 MODULE_AUTHOR("Loc Ho <lho@apm.com>");
1832 MODULE_LICENSE("GPL");
1833 MODULE_VERSION("1.0");
1834