xref: /openbmc/linux/drivers/dma/xgene-dma.c (revision 9b93eb47)
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  * @err_irq: DMA error irq number
291  * @ring_num: start id number for DMA ring
292  * @csr_dma: base for DMA register access
293  * @csr_ring: base for DMA ring register access
294  * @csr_ring_cmd: base for DMA ring command register access
295  * @csr_efuse: base for efuse register access
296  * @dma_dev: embedded struct dma_device
297  * @chan: reference to X-Gene DMA channels
298  */
299 struct xgene_dma {
300 	struct device *dev;
301 	struct clk *clk;
302 	int err_irq;
303 	int ring_num;
304 	void __iomem *csr_dma;
305 	void __iomem *csr_ring;
306 	void __iomem *csr_ring_cmd;
307 	void __iomem *csr_efuse;
308 	struct dma_device dma_dev[XGENE_DMA_MAX_CHANNEL];
309 	struct xgene_dma_chan chan[XGENE_DMA_MAX_CHANNEL];
310 };
311 
312 static const char * const xgene_dma_desc_err[] = {
313 	[ERR_DESC_AXI] = "AXI error when reading src/dst link list",
314 	[ERR_BAD_DESC] = "ERR or El_ERR fields not set to zero in desc",
315 	[ERR_READ_DATA_AXI] = "AXI error when reading data",
316 	[ERR_WRITE_DATA_AXI] = "AXI error when writing data",
317 	[ERR_FBP_TIMEOUT] = "Timeout on bufpool fetch",
318 	[ERR_ECC] = "ECC double bit error",
319 	[ERR_DIFF_SIZE] = "Bufpool too small to hold all the DIF result",
320 	[ERR_SCT_GAT_LEN] = "Gather and scatter data length not same",
321 	[ERR_CRC_ERR] = "CRC error",
322 	[ERR_CHKSUM] = "Checksum error",
323 	[ERR_DIF] = "DIF error",
324 };
325 
326 static const char * const xgene_dma_err[] = {
327 	[ERR_DIF_SIZE_INT] = "DIF size error",
328 	[ERR_GS_ERR_INT] = "Gather scatter not same size error",
329 	[ERR_FPB_TIMEO_INT] = "Free pool time out error",
330 	[ERR_WFIFO_OVF_INT] = "Write FIFO over flow error",
331 	[ERR_RFIFO_OVF_INT] = "Read FIFO over flow error",
332 	[ERR_WR_TIMEO_INT] = "Write time out error",
333 	[ERR_RD_TIMEO_INT] = "Read time out error",
334 	[ERR_WR_ERR_INT] = "HBF bus write error",
335 	[ERR_RD_ERR_INT] = "HBF bus read error",
336 	[ERR_BAD_DESC_INT] = "Ring descriptor HE0 not set error",
337 	[ERR_DESC_DST_INT] = "HFB reading dst link address error",
338 	[ERR_DESC_SRC_INT] = "HFB reading src link address error",
339 };
340 
341 static bool is_pq_enabled(struct xgene_dma *pdma)
342 {
343 	u32 val;
344 
345 	val = ioread32(pdma->csr_efuse + XGENE_SOC_JTAG1_SHADOW);
346 	return !(val & XGENE_DMA_PQ_DISABLE_MASK);
347 }
348 
349 static u64 xgene_dma_encode_len(size_t len)
350 {
351 	return (len < XGENE_DMA_MAX_BYTE_CNT) ?
352 		((u64)len << XGENE_DMA_DESC_BUFLEN_POS) :
353 		XGENE_DMA_16K_BUFFER_LEN_CODE;
354 }
355 
356 static u8 xgene_dma_encode_xor_flyby(u32 src_cnt)
357 {
358 	static u8 flyby_type[] = {
359 		FLYBY_2SRC_XOR, /* Dummy */
360 		FLYBY_2SRC_XOR, /* Dummy */
361 		FLYBY_2SRC_XOR,
362 		FLYBY_3SRC_XOR,
363 		FLYBY_4SRC_XOR,
364 		FLYBY_5SRC_XOR
365 	};
366 
367 	return flyby_type[src_cnt];
368 }
369 
370 static void xgene_dma_set_src_buffer(__le64 *ext8, size_t *len,
371 				     dma_addr_t *paddr)
372 {
373 	size_t nbytes = (*len < XGENE_DMA_MAX_BYTE_CNT) ?
374 			*len : XGENE_DMA_MAX_BYTE_CNT;
375 
376 	*ext8 |= cpu_to_le64(*paddr);
377 	*ext8 |= cpu_to_le64(xgene_dma_encode_len(nbytes));
378 	*len -= nbytes;
379 	*paddr += nbytes;
380 }
381 
382 static __le64 *xgene_dma_lookup_ext8(struct xgene_dma_desc_hw *desc, int idx)
383 {
384 	switch (idx) {
385 	case 0:
386 		return &desc->m1;
387 	case 1:
388 		return &desc->m0;
389 	case 2:
390 		return &desc->m3;
391 	case 3:
392 		return &desc->m2;
393 	default:
394 		pr_err("Invalid dma descriptor index\n");
395 	}
396 
397 	return NULL;
398 }
399 
400 static void xgene_dma_init_desc(struct xgene_dma_desc_hw *desc,
401 				u16 dst_ring_num)
402 {
403 	desc->m0 |= cpu_to_le64(XGENE_DMA_DESC_IN_BIT);
404 	desc->m0 |= cpu_to_le64((u64)XGENE_DMA_RING_OWNER_DMA <<
405 				XGENE_DMA_DESC_RTYPE_POS);
406 	desc->m1 |= cpu_to_le64(XGENE_DMA_DESC_C_BIT);
407 	desc->m3 |= cpu_to_le64((u64)dst_ring_num <<
408 				XGENE_DMA_DESC_HOENQ_NUM_POS);
409 }
410 
411 static void xgene_dma_prep_xor_desc(struct xgene_dma_chan *chan,
412 				    struct xgene_dma_desc_sw *desc_sw,
413 				    dma_addr_t *dst, dma_addr_t *src,
414 				    u32 src_cnt, size_t *nbytes,
415 				    const u8 *scf)
416 {
417 	struct xgene_dma_desc_hw *desc1, *desc2;
418 	size_t len = *nbytes;
419 	int i;
420 
421 	desc1 = &desc_sw->desc1;
422 	desc2 = &desc_sw->desc2;
423 
424 	/* Initialize DMA descriptor */
425 	xgene_dma_init_desc(desc1, chan->tx_ring.dst_ring_num);
426 
427 	/* Set destination address */
428 	desc1->m2 |= cpu_to_le64(XGENE_DMA_DESC_DR_BIT);
429 	desc1->m3 |= cpu_to_le64(*dst);
430 
431 	/* We have multiple source addresses, so need to set NV bit*/
432 	desc1->m0 |= cpu_to_le64(XGENE_DMA_DESC_NV_BIT);
433 
434 	/* Set flyby opcode */
435 	desc1->m2 |= cpu_to_le64(xgene_dma_encode_xor_flyby(src_cnt));
436 
437 	/* Set 1st to 5th source addresses */
438 	for (i = 0; i < src_cnt; i++) {
439 		len = *nbytes;
440 		xgene_dma_set_src_buffer((i == 0) ? &desc1->m1 :
441 					 xgene_dma_lookup_ext8(desc2, i - 1),
442 					 &len, &src[i]);
443 		desc1->m2 |= cpu_to_le64((scf[i] << ((i + 1) * 8)));
444 	}
445 
446 	/* Update meta data */
447 	*nbytes = len;
448 	*dst += XGENE_DMA_MAX_BYTE_CNT;
449 
450 	/* We need always 64B descriptor to perform xor or pq operations */
451 	desc_sw->flags |= XGENE_DMA_FLAG_64B_DESC;
452 }
453 
454 static dma_cookie_t xgene_dma_tx_submit(struct dma_async_tx_descriptor *tx)
455 {
456 	struct xgene_dma_desc_sw *desc;
457 	struct xgene_dma_chan *chan;
458 	dma_cookie_t cookie;
459 
460 	if (unlikely(!tx))
461 		return -EINVAL;
462 
463 	chan = to_dma_chan(tx->chan);
464 	desc = to_dma_desc_sw(tx);
465 
466 	spin_lock_bh(&chan->lock);
467 
468 	cookie = dma_cookie_assign(tx);
469 
470 	/* Add this transaction list onto the tail of the pending queue */
471 	list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
472 
473 	spin_unlock_bh(&chan->lock);
474 
475 	return cookie;
476 }
477 
478 static void xgene_dma_clean_descriptor(struct xgene_dma_chan *chan,
479 				       struct xgene_dma_desc_sw *desc)
480 {
481 	list_del(&desc->node);
482 	chan_dbg(chan, "LD %p free\n", desc);
483 	dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
484 }
485 
486 static struct xgene_dma_desc_sw *xgene_dma_alloc_descriptor(
487 				 struct xgene_dma_chan *chan)
488 {
489 	struct xgene_dma_desc_sw *desc;
490 	dma_addr_t phys;
491 
492 	desc = dma_pool_zalloc(chan->desc_pool, GFP_NOWAIT, &phys);
493 	if (!desc) {
494 		chan_err(chan, "Failed to allocate LDs\n");
495 		return NULL;
496 	}
497 
498 	INIT_LIST_HEAD(&desc->tx_list);
499 	desc->tx.phys = phys;
500 	desc->tx.tx_submit = xgene_dma_tx_submit;
501 	dma_async_tx_descriptor_init(&desc->tx, &chan->dma_chan);
502 
503 	chan_dbg(chan, "LD %p allocated\n", desc);
504 
505 	return desc;
506 }
507 
508 /**
509  * xgene_dma_clean_completed_descriptor - free all descriptors which
510  * has been completed and acked
511  * @chan: X-Gene DMA channel
512  *
513  * This function is used on all completed and acked descriptors.
514  */
515 static void xgene_dma_clean_completed_descriptor(struct xgene_dma_chan *chan)
516 {
517 	struct xgene_dma_desc_sw *desc, *_desc;
518 
519 	/* Run the callback for each descriptor, in order */
520 	list_for_each_entry_safe(desc, _desc, &chan->ld_completed, node) {
521 		if (async_tx_test_ack(&desc->tx))
522 			xgene_dma_clean_descriptor(chan, desc);
523 	}
524 }
525 
526 /**
527  * xgene_dma_run_tx_complete_actions - cleanup a single link descriptor
528  * @chan: X-Gene DMA channel
529  * @desc: descriptor to cleanup and free
530  *
531  * This function is used on a descriptor which has been executed by the DMA
532  * controller. It will run any callbacks, submit any dependencies.
533  */
534 static void xgene_dma_run_tx_complete_actions(struct xgene_dma_chan *chan,
535 					      struct xgene_dma_desc_sw *desc)
536 {
537 	struct dma_async_tx_descriptor *tx = &desc->tx;
538 
539 	/*
540 	 * If this is not the last transaction in the group,
541 	 * then no need to complete cookie and run any callback as
542 	 * this is not the tx_descriptor which had been sent to caller
543 	 * of this DMA request
544 	 */
545 
546 	if (tx->cookie == 0)
547 		return;
548 
549 	dma_cookie_complete(tx);
550 	dma_descriptor_unmap(tx);
551 
552 	/* Run the link descriptor callback function */
553 	dmaengine_desc_get_callback_invoke(tx, NULL);
554 
555 	/* Run any dependencies */
556 	dma_run_dependencies(tx);
557 }
558 
559 /**
560  * xgene_dma_clean_running_descriptor - move the completed descriptor from
561  * ld_running to ld_completed
562  * @chan: X-Gene DMA channel
563  * @desc: the descriptor which is completed
564  *
565  * Free the descriptor directly if acked by async_tx api,
566  * else move it to queue ld_completed.
567  */
568 static void xgene_dma_clean_running_descriptor(struct xgene_dma_chan *chan,
569 					       struct xgene_dma_desc_sw *desc)
570 {
571 	/* Remove from the list of running transactions */
572 	list_del(&desc->node);
573 
574 	/*
575 	 * the client is allowed to attach dependent operations
576 	 * until 'ack' is set
577 	 */
578 	if (!async_tx_test_ack(&desc->tx)) {
579 		/*
580 		 * Move this descriptor to the list of descriptors which is
581 		 * completed, but still awaiting the 'ack' bit to be set.
582 		 */
583 		list_add_tail(&desc->node, &chan->ld_completed);
584 		return;
585 	}
586 
587 	chan_dbg(chan, "LD %p free\n", desc);
588 	dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
589 }
590 
591 static void xgene_chan_xfer_request(struct xgene_dma_chan *chan,
592 				    struct xgene_dma_desc_sw *desc_sw)
593 {
594 	struct xgene_dma_ring *ring = &chan->tx_ring;
595 	struct xgene_dma_desc_hw *desc_hw;
596 
597 	/* Get hw descriptor from DMA tx ring */
598 	desc_hw = &ring->desc_hw[ring->head];
599 
600 	/*
601 	 * Increment the head count to point next
602 	 * descriptor for next time
603 	 */
604 	if (++ring->head == ring->slots)
605 		ring->head = 0;
606 
607 	/* Copy prepared sw descriptor data to hw descriptor */
608 	memcpy(desc_hw, &desc_sw->desc1, sizeof(*desc_hw));
609 
610 	/*
611 	 * Check if we have prepared 64B descriptor,
612 	 * in this case we need one more hw descriptor
613 	 */
614 	if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) {
615 		desc_hw = &ring->desc_hw[ring->head];
616 
617 		if (++ring->head == ring->slots)
618 			ring->head = 0;
619 
620 		memcpy(desc_hw, &desc_sw->desc2, sizeof(*desc_hw));
621 	}
622 
623 	/* Increment the pending transaction count */
624 	chan->pending += ((desc_sw->flags &
625 			  XGENE_DMA_FLAG_64B_DESC) ? 2 : 1);
626 
627 	/* Notify the hw that we have descriptor ready for execution */
628 	iowrite32((desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) ?
629 		  2 : 1, ring->cmd);
630 }
631 
632 /**
633  * xgene_chan_xfer_ld_pending - push any pending transactions to hw
634  * @chan : X-Gene DMA channel
635  *
636  * LOCKING: must hold chan->lock
637  */
638 static void xgene_chan_xfer_ld_pending(struct xgene_dma_chan *chan)
639 {
640 	struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
641 
642 	/*
643 	 * If the list of pending descriptors is empty, then we
644 	 * don't need to do any work at all
645 	 */
646 	if (list_empty(&chan->ld_pending)) {
647 		chan_dbg(chan, "No pending LDs\n");
648 		return;
649 	}
650 
651 	/*
652 	 * Move elements from the queue of pending transactions onto the list
653 	 * of running transactions and push it to hw for further executions
654 	 */
655 	list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_pending, node) {
656 		/*
657 		 * Check if have pushed max number of transactions to hw
658 		 * as capable, so let's stop here and will push remaining
659 		 * elements from pening ld queue after completing some
660 		 * descriptors that we have already pushed
661 		 */
662 		if (chan->pending >= chan->max_outstanding)
663 			return;
664 
665 		xgene_chan_xfer_request(chan, desc_sw);
666 
667 		/*
668 		 * Delete this element from ld pending queue and append it to
669 		 * ld running queue
670 		 */
671 		list_move_tail(&desc_sw->node, &chan->ld_running);
672 	}
673 }
674 
675 /**
676  * xgene_dma_cleanup_descriptors - cleanup link descriptors which are completed
677  * and move them to ld_completed to free until flag 'ack' is set
678  * @chan: X-Gene DMA channel
679  *
680  * This function is used on descriptors which have been executed by the DMA
681  * controller. It will run any callbacks, submit any dependencies, then
682  * free these descriptors if flag 'ack' is set.
683  */
684 static void xgene_dma_cleanup_descriptors(struct xgene_dma_chan *chan)
685 {
686 	struct xgene_dma_ring *ring = &chan->rx_ring;
687 	struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
688 	struct xgene_dma_desc_hw *desc_hw;
689 	struct list_head ld_completed;
690 	u8 status;
691 
692 	INIT_LIST_HEAD(&ld_completed);
693 
694 	spin_lock(&chan->lock);
695 
696 	/* Clean already completed and acked descriptors */
697 	xgene_dma_clean_completed_descriptor(chan);
698 
699 	/* Move all completed descriptors to ld completed queue, in order */
700 	list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_running, node) {
701 		/* Get subsequent hw descriptor from DMA rx ring */
702 		desc_hw = &ring->desc_hw[ring->head];
703 
704 		/* Check if this descriptor has been completed */
705 		if (unlikely(le64_to_cpu(desc_hw->m0) ==
706 			     XGENE_DMA_DESC_EMPTY_SIGNATURE))
707 			break;
708 
709 		if (++ring->head == ring->slots)
710 			ring->head = 0;
711 
712 		/* Check if we have any error with DMA transactions */
713 		status = XGENE_DMA_DESC_STATUS(
714 				XGENE_DMA_DESC_ELERR_RD(le64_to_cpu(
715 							desc_hw->m0)),
716 				XGENE_DMA_DESC_LERR_RD(le64_to_cpu(
717 						       desc_hw->m0)));
718 		if (status) {
719 			/* Print the DMA error type */
720 			chan_err(chan, "%s\n", xgene_dma_desc_err[status]);
721 
722 			/*
723 			 * We have DMA transactions error here. Dump DMA Tx
724 			 * and Rx descriptors for this request */
725 			XGENE_DMA_DESC_DUMP(&desc_sw->desc1,
726 					    "X-Gene DMA TX DESC1: ");
727 
728 			if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC)
729 				XGENE_DMA_DESC_DUMP(&desc_sw->desc2,
730 						    "X-Gene DMA TX DESC2: ");
731 
732 			XGENE_DMA_DESC_DUMP(desc_hw,
733 					    "X-Gene DMA RX ERR DESC: ");
734 		}
735 
736 		/* Notify the hw about this completed descriptor */
737 		iowrite32(-1, ring->cmd);
738 
739 		/* Mark this hw descriptor as processed */
740 		desc_hw->m0 = cpu_to_le64(XGENE_DMA_DESC_EMPTY_SIGNATURE);
741 
742 		/*
743 		 * Decrement the pending transaction count
744 		 * as we have processed one
745 		 */
746 		chan->pending -= ((desc_sw->flags &
747 				  XGENE_DMA_FLAG_64B_DESC) ? 2 : 1);
748 
749 		/*
750 		 * Delete this node from ld running queue and append it to
751 		 * ld completed queue for further processing
752 		 */
753 		list_move_tail(&desc_sw->node, &ld_completed);
754 	}
755 
756 	/*
757 	 * Start any pending transactions automatically
758 	 * In the ideal case, we keep the DMA controller busy while we go
759 	 * ahead and free the descriptors below.
760 	 */
761 	xgene_chan_xfer_ld_pending(chan);
762 
763 	spin_unlock(&chan->lock);
764 
765 	/* Run the callback for each descriptor, in order */
766 	list_for_each_entry_safe(desc_sw, _desc_sw, &ld_completed, node) {
767 		xgene_dma_run_tx_complete_actions(chan, desc_sw);
768 		xgene_dma_clean_running_descriptor(chan, desc_sw);
769 	}
770 }
771 
772 static int xgene_dma_alloc_chan_resources(struct dma_chan *dchan)
773 {
774 	struct xgene_dma_chan *chan = to_dma_chan(dchan);
775 
776 	/* Has this channel already been allocated? */
777 	if (chan->desc_pool)
778 		return 1;
779 
780 	chan->desc_pool = dma_pool_create(chan->name, chan->dev,
781 					  sizeof(struct xgene_dma_desc_sw),
782 					  0, 0);
783 	if (!chan->desc_pool) {
784 		chan_err(chan, "Failed to allocate descriptor pool\n");
785 		return -ENOMEM;
786 	}
787 
788 	chan_dbg(chan, "Allocate descriptor pool\n");
789 
790 	return 1;
791 }
792 
793 /**
794  * xgene_dma_free_desc_list - Free all descriptors in a queue
795  * @chan: X-Gene DMA channel
796  * @list: the list to free
797  *
798  * LOCKING: must hold chan->lock
799  */
800 static void xgene_dma_free_desc_list(struct xgene_dma_chan *chan,
801 				     struct list_head *list)
802 {
803 	struct xgene_dma_desc_sw *desc, *_desc;
804 
805 	list_for_each_entry_safe(desc, _desc, list, node)
806 		xgene_dma_clean_descriptor(chan, desc);
807 }
808 
809 static void xgene_dma_free_chan_resources(struct dma_chan *dchan)
810 {
811 	struct xgene_dma_chan *chan = to_dma_chan(dchan);
812 
813 	chan_dbg(chan, "Free all resources\n");
814 
815 	if (!chan->desc_pool)
816 		return;
817 
818 	/* Process all running descriptor */
819 	xgene_dma_cleanup_descriptors(chan);
820 
821 	spin_lock_bh(&chan->lock);
822 
823 	/* Clean all link descriptor queues */
824 	xgene_dma_free_desc_list(chan, &chan->ld_pending);
825 	xgene_dma_free_desc_list(chan, &chan->ld_running);
826 	xgene_dma_free_desc_list(chan, &chan->ld_completed);
827 
828 	spin_unlock_bh(&chan->lock);
829 
830 	/* Delete this channel DMA pool */
831 	dma_pool_destroy(chan->desc_pool);
832 	chan->desc_pool = NULL;
833 }
834 
835 static struct dma_async_tx_descriptor *xgene_dma_prep_xor(
836 	struct dma_chan *dchan, dma_addr_t dst,	dma_addr_t *src,
837 	u32 src_cnt, size_t len, unsigned long flags)
838 {
839 	struct xgene_dma_desc_sw *first = NULL, *new;
840 	struct xgene_dma_chan *chan;
841 	static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {
842 				0x01, 0x01, 0x01, 0x01, 0x01};
843 
844 	if (unlikely(!dchan || !len))
845 		return NULL;
846 
847 	chan = to_dma_chan(dchan);
848 
849 	do {
850 		/* Allocate the link descriptor from DMA pool */
851 		new = xgene_dma_alloc_descriptor(chan);
852 		if (!new)
853 			goto fail;
854 
855 		/* Prepare xor DMA descriptor */
856 		xgene_dma_prep_xor_desc(chan, new, &dst, src,
857 					src_cnt, &len, multi);
858 
859 		if (!first)
860 			first = new;
861 
862 		new->tx.cookie = 0;
863 		async_tx_ack(&new->tx);
864 
865 		/* Insert the link descriptor to the LD ring */
866 		list_add_tail(&new->node, &first->tx_list);
867 	} while (len);
868 
869 	new->tx.flags = flags; /* client is in control of this ack */
870 	new->tx.cookie = -EBUSY;
871 	list_splice(&first->tx_list, &new->tx_list);
872 
873 	return &new->tx;
874 
875 fail:
876 	if (!first)
877 		return NULL;
878 
879 	xgene_dma_free_desc_list(chan, &first->tx_list);
880 	return NULL;
881 }
882 
883 static struct dma_async_tx_descriptor *xgene_dma_prep_pq(
884 	struct dma_chan *dchan, dma_addr_t *dst, dma_addr_t *src,
885 	u32 src_cnt, const u8 *scf, size_t len, unsigned long flags)
886 {
887 	struct xgene_dma_desc_sw *first = NULL, *new;
888 	struct xgene_dma_chan *chan;
889 	size_t _len = len;
890 	dma_addr_t _src[XGENE_DMA_MAX_XOR_SRC];
891 	static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {0x01, 0x01, 0x01, 0x01, 0x01};
892 
893 	if (unlikely(!dchan || !len))
894 		return NULL;
895 
896 	chan = to_dma_chan(dchan);
897 
898 	/*
899 	 * Save source addresses on local variable, may be we have to
900 	 * prepare two descriptor to generate P and Q if both enabled
901 	 * in the flags by client
902 	 */
903 	memcpy(_src, src, sizeof(*src) * src_cnt);
904 
905 	if (flags & DMA_PREP_PQ_DISABLE_P)
906 		len = 0;
907 
908 	if (flags & DMA_PREP_PQ_DISABLE_Q)
909 		_len = 0;
910 
911 	do {
912 		/* Allocate the link descriptor from DMA pool */
913 		new = xgene_dma_alloc_descriptor(chan);
914 		if (!new)
915 			goto fail;
916 
917 		if (!first)
918 			first = new;
919 
920 		new->tx.cookie = 0;
921 		async_tx_ack(&new->tx);
922 
923 		/* Insert the link descriptor to the LD ring */
924 		list_add_tail(&new->node, &first->tx_list);
925 
926 		/*
927 		 * Prepare DMA descriptor to generate P,
928 		 * if DMA_PREP_PQ_DISABLE_P flag is not set
929 		 */
930 		if (len) {
931 			xgene_dma_prep_xor_desc(chan, new, &dst[0], src,
932 						src_cnt, &len, multi);
933 			continue;
934 		}
935 
936 		/*
937 		 * Prepare DMA descriptor to generate Q,
938 		 * if DMA_PREP_PQ_DISABLE_Q flag is not set
939 		 */
940 		if (_len) {
941 			xgene_dma_prep_xor_desc(chan, new, &dst[1], _src,
942 						src_cnt, &_len, scf);
943 		}
944 	} while (len || _len);
945 
946 	new->tx.flags = flags; /* client is in control of this ack */
947 	new->tx.cookie = -EBUSY;
948 	list_splice(&first->tx_list, &new->tx_list);
949 
950 	return &new->tx;
951 
952 fail:
953 	if (!first)
954 		return NULL;
955 
956 	xgene_dma_free_desc_list(chan, &first->tx_list);
957 	return NULL;
958 }
959 
960 static void xgene_dma_issue_pending(struct dma_chan *dchan)
961 {
962 	struct xgene_dma_chan *chan = to_dma_chan(dchan);
963 
964 	spin_lock_bh(&chan->lock);
965 	xgene_chan_xfer_ld_pending(chan);
966 	spin_unlock_bh(&chan->lock);
967 }
968 
969 static enum dma_status xgene_dma_tx_status(struct dma_chan *dchan,
970 					   dma_cookie_t cookie,
971 					   struct dma_tx_state *txstate)
972 {
973 	return dma_cookie_status(dchan, cookie, txstate);
974 }
975 
976 static void xgene_dma_tasklet_cb(unsigned long data)
977 {
978 	struct xgene_dma_chan *chan = (struct xgene_dma_chan *)data;
979 
980 	/* Run all cleanup for descriptors which have been completed */
981 	xgene_dma_cleanup_descriptors(chan);
982 
983 	/* Re-enable DMA channel IRQ */
984 	enable_irq(chan->rx_irq);
985 }
986 
987 static irqreturn_t xgene_dma_chan_ring_isr(int irq, void *id)
988 {
989 	struct xgene_dma_chan *chan = (struct xgene_dma_chan *)id;
990 
991 	BUG_ON(!chan);
992 
993 	/*
994 	 * Disable DMA channel IRQ until we process completed
995 	 * descriptors
996 	 */
997 	disable_irq_nosync(chan->rx_irq);
998 
999 	/*
1000 	 * Schedule the tasklet to handle all cleanup of the current
1001 	 * transaction. It will start a new transaction if there is
1002 	 * one pending.
1003 	 */
1004 	tasklet_schedule(&chan->tasklet);
1005 
1006 	return IRQ_HANDLED;
1007 }
1008 
1009 static irqreturn_t xgene_dma_err_isr(int irq, void *id)
1010 {
1011 	struct xgene_dma *pdma = (struct xgene_dma *)id;
1012 	unsigned long int_mask;
1013 	u32 val, i;
1014 
1015 	val = ioread32(pdma->csr_dma + XGENE_DMA_INT);
1016 
1017 	/* Clear DMA interrupts */
1018 	iowrite32(val, pdma->csr_dma + XGENE_DMA_INT);
1019 
1020 	/* Print DMA error info */
1021 	int_mask = val >> XGENE_DMA_INT_MASK_SHIFT;
1022 	for_each_set_bit(i, &int_mask, ARRAY_SIZE(xgene_dma_err))
1023 		dev_err(pdma->dev,
1024 			"Interrupt status 0x%08X %s\n", val, xgene_dma_err[i]);
1025 
1026 	return IRQ_HANDLED;
1027 }
1028 
1029 static void xgene_dma_wr_ring_state(struct xgene_dma_ring *ring)
1030 {
1031 	int i;
1032 
1033 	iowrite32(ring->num, ring->pdma->csr_ring + XGENE_DMA_RING_STATE);
1034 
1035 	for (i = 0; i < XGENE_DMA_RING_NUM_CONFIG; i++)
1036 		iowrite32(ring->state[i], ring->pdma->csr_ring +
1037 			  XGENE_DMA_RING_STATE_WR_BASE + (i * 4));
1038 }
1039 
1040 static void xgene_dma_clr_ring_state(struct xgene_dma_ring *ring)
1041 {
1042 	memset(ring->state, 0, sizeof(u32) * XGENE_DMA_RING_NUM_CONFIG);
1043 	xgene_dma_wr_ring_state(ring);
1044 }
1045 
1046 static void xgene_dma_setup_ring(struct xgene_dma_ring *ring)
1047 {
1048 	void *ring_cfg = ring->state;
1049 	u64 addr = ring->desc_paddr;
1050 	u32 i, val;
1051 
1052 	ring->slots = ring->size / XGENE_DMA_RING_WQ_DESC_SIZE;
1053 
1054 	/* Clear DMA ring state */
1055 	xgene_dma_clr_ring_state(ring);
1056 
1057 	/* Set DMA ring type */
1058 	XGENE_DMA_RING_TYPE_SET(ring_cfg, XGENE_DMA_RING_TYPE_REGULAR);
1059 
1060 	if (ring->owner == XGENE_DMA_RING_OWNER_DMA) {
1061 		/* Set recombination buffer and timeout */
1062 		XGENE_DMA_RING_RECOMBBUF_SET(ring_cfg);
1063 		XGENE_DMA_RING_RECOMTIMEOUTL_SET(ring_cfg);
1064 		XGENE_DMA_RING_RECOMTIMEOUTH_SET(ring_cfg);
1065 	}
1066 
1067 	/* Initialize DMA ring state */
1068 	XGENE_DMA_RING_SELTHRSH_SET(ring_cfg);
1069 	XGENE_DMA_RING_ACCEPTLERR_SET(ring_cfg);
1070 	XGENE_DMA_RING_COHERENT_SET(ring_cfg);
1071 	XGENE_DMA_RING_ADDRL_SET(ring_cfg, addr);
1072 	XGENE_DMA_RING_ADDRH_SET(ring_cfg, addr);
1073 	XGENE_DMA_RING_SIZE_SET(ring_cfg, ring->cfgsize);
1074 
1075 	/* Write DMA ring configurations */
1076 	xgene_dma_wr_ring_state(ring);
1077 
1078 	/* Set DMA ring id */
1079 	iowrite32(XGENE_DMA_RING_ID_SETUP(ring->id),
1080 		  ring->pdma->csr_ring + XGENE_DMA_RING_ID);
1081 
1082 	/* Set DMA ring buffer */
1083 	iowrite32(XGENE_DMA_RING_ID_BUF_SETUP(ring->num),
1084 		  ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
1085 
1086 	if (ring->owner != XGENE_DMA_RING_OWNER_CPU)
1087 		return;
1088 
1089 	/* Set empty signature to DMA Rx ring descriptors */
1090 	for (i = 0; i < ring->slots; i++) {
1091 		struct xgene_dma_desc_hw *desc;
1092 
1093 		desc = &ring->desc_hw[i];
1094 		desc->m0 = cpu_to_le64(XGENE_DMA_DESC_EMPTY_SIGNATURE);
1095 	}
1096 
1097 	/* Enable DMA Rx ring interrupt */
1098 	val = ioread32(ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
1099 	XGENE_DMA_RING_NE_INT_MODE_SET(val, ring->buf_num);
1100 	iowrite32(val, ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
1101 }
1102 
1103 static void xgene_dma_clear_ring(struct xgene_dma_ring *ring)
1104 {
1105 	u32 ring_id, val;
1106 
1107 	if (ring->owner == XGENE_DMA_RING_OWNER_CPU) {
1108 		/* Disable DMA Rx ring interrupt */
1109 		val = ioread32(ring->pdma->csr_ring +
1110 			       XGENE_DMA_RING_NE_INT_MODE);
1111 		XGENE_DMA_RING_NE_INT_MODE_RESET(val, ring->buf_num);
1112 		iowrite32(val, ring->pdma->csr_ring +
1113 			  XGENE_DMA_RING_NE_INT_MODE);
1114 	}
1115 
1116 	/* Clear DMA ring state */
1117 	ring_id = XGENE_DMA_RING_ID_SETUP(ring->id);
1118 	iowrite32(ring_id, ring->pdma->csr_ring + XGENE_DMA_RING_ID);
1119 
1120 	iowrite32(0, ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
1121 	xgene_dma_clr_ring_state(ring);
1122 }
1123 
1124 static void xgene_dma_set_ring_cmd(struct xgene_dma_ring *ring)
1125 {
1126 	ring->cmd_base = ring->pdma->csr_ring_cmd +
1127 				XGENE_DMA_RING_CMD_BASE_OFFSET((ring->num -
1128 							  XGENE_DMA_RING_NUM));
1129 
1130 	ring->cmd = ring->cmd_base + XGENE_DMA_RING_CMD_OFFSET;
1131 }
1132 
1133 static int xgene_dma_get_ring_size(struct xgene_dma_chan *chan,
1134 				   enum xgene_dma_ring_cfgsize cfgsize)
1135 {
1136 	int size;
1137 
1138 	switch (cfgsize) {
1139 	case XGENE_DMA_RING_CFG_SIZE_512B:
1140 		size = 0x200;
1141 		break;
1142 	case XGENE_DMA_RING_CFG_SIZE_2KB:
1143 		size = 0x800;
1144 		break;
1145 	case XGENE_DMA_RING_CFG_SIZE_16KB:
1146 		size = 0x4000;
1147 		break;
1148 	case XGENE_DMA_RING_CFG_SIZE_64KB:
1149 		size = 0x10000;
1150 		break;
1151 	case XGENE_DMA_RING_CFG_SIZE_512KB:
1152 		size = 0x80000;
1153 		break;
1154 	default:
1155 		chan_err(chan, "Unsupported cfg ring size %d\n", cfgsize);
1156 		return -EINVAL;
1157 	}
1158 
1159 	return size;
1160 }
1161 
1162 static void xgene_dma_delete_ring_one(struct xgene_dma_ring *ring)
1163 {
1164 	/* Clear DMA ring configurations */
1165 	xgene_dma_clear_ring(ring);
1166 
1167 	/* De-allocate DMA ring descriptor */
1168 	if (ring->desc_vaddr) {
1169 		dma_free_coherent(ring->pdma->dev, ring->size,
1170 				  ring->desc_vaddr, ring->desc_paddr);
1171 		ring->desc_vaddr = NULL;
1172 	}
1173 }
1174 
1175 static void xgene_dma_delete_chan_rings(struct xgene_dma_chan *chan)
1176 {
1177 	xgene_dma_delete_ring_one(&chan->rx_ring);
1178 	xgene_dma_delete_ring_one(&chan->tx_ring);
1179 }
1180 
1181 static int xgene_dma_create_ring_one(struct xgene_dma_chan *chan,
1182 				     struct xgene_dma_ring *ring,
1183 				     enum xgene_dma_ring_cfgsize cfgsize)
1184 {
1185 	int ret;
1186 
1187 	/* Setup DMA ring descriptor variables */
1188 	ring->pdma = chan->pdma;
1189 	ring->cfgsize = cfgsize;
1190 	ring->num = chan->pdma->ring_num++;
1191 	ring->id = XGENE_DMA_RING_ID_GET(ring->owner, ring->buf_num);
1192 
1193 	ret = xgene_dma_get_ring_size(chan, cfgsize);
1194 	if (ret <= 0)
1195 		return ret;
1196 	ring->size = ret;
1197 
1198 	/* Allocate memory for DMA ring descriptor */
1199 	ring->desc_vaddr = dma_alloc_coherent(chan->dev, ring->size,
1200 					      &ring->desc_paddr, GFP_KERNEL);
1201 	if (!ring->desc_vaddr) {
1202 		chan_err(chan, "Failed to allocate ring desc\n");
1203 		return -ENOMEM;
1204 	}
1205 
1206 	/* Configure and enable DMA ring */
1207 	xgene_dma_set_ring_cmd(ring);
1208 	xgene_dma_setup_ring(ring);
1209 
1210 	return 0;
1211 }
1212 
1213 static int xgene_dma_create_chan_rings(struct xgene_dma_chan *chan)
1214 {
1215 	struct xgene_dma_ring *rx_ring = &chan->rx_ring;
1216 	struct xgene_dma_ring *tx_ring = &chan->tx_ring;
1217 	int ret;
1218 
1219 	/* Create DMA Rx ring descriptor */
1220 	rx_ring->owner = XGENE_DMA_RING_OWNER_CPU;
1221 	rx_ring->buf_num = XGENE_DMA_CPU_BUFNUM + chan->id;
1222 
1223 	ret = xgene_dma_create_ring_one(chan, rx_ring,
1224 					XGENE_DMA_RING_CFG_SIZE_64KB);
1225 	if (ret)
1226 		return ret;
1227 
1228 	chan_dbg(chan, "Rx ring id 0x%X num %d desc 0x%p\n",
1229 		 rx_ring->id, rx_ring->num, rx_ring->desc_vaddr);
1230 
1231 	/* Create DMA Tx ring descriptor */
1232 	tx_ring->owner = XGENE_DMA_RING_OWNER_DMA;
1233 	tx_ring->buf_num = XGENE_DMA_BUFNUM + chan->id;
1234 
1235 	ret = xgene_dma_create_ring_one(chan, tx_ring,
1236 					XGENE_DMA_RING_CFG_SIZE_64KB);
1237 	if (ret) {
1238 		xgene_dma_delete_ring_one(rx_ring);
1239 		return ret;
1240 	}
1241 
1242 	tx_ring->dst_ring_num = XGENE_DMA_RING_DST_ID(rx_ring->num);
1243 
1244 	chan_dbg(chan,
1245 		 "Tx ring id 0x%X num %d desc 0x%p\n",
1246 		 tx_ring->id, tx_ring->num, tx_ring->desc_vaddr);
1247 
1248 	/* Set the max outstanding request possible to this channel */
1249 	chan->max_outstanding = tx_ring->slots;
1250 
1251 	return ret;
1252 }
1253 
1254 static int xgene_dma_init_rings(struct xgene_dma *pdma)
1255 {
1256 	int ret, i, j;
1257 
1258 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1259 		ret = xgene_dma_create_chan_rings(&pdma->chan[i]);
1260 		if (ret) {
1261 			for (j = 0; j < i; j++)
1262 				xgene_dma_delete_chan_rings(&pdma->chan[j]);
1263 			return ret;
1264 		}
1265 	}
1266 
1267 	return ret;
1268 }
1269 
1270 static void xgene_dma_enable(struct xgene_dma *pdma)
1271 {
1272 	u32 val;
1273 
1274 	/* Configure and enable DMA engine */
1275 	val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
1276 	XGENE_DMA_CH_SETUP(val);
1277 	XGENE_DMA_ENABLE(val);
1278 	iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
1279 }
1280 
1281 static void xgene_dma_disable(struct xgene_dma *pdma)
1282 {
1283 	u32 val;
1284 
1285 	val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
1286 	XGENE_DMA_DISABLE(val);
1287 	iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
1288 }
1289 
1290 static void xgene_dma_mask_interrupts(struct xgene_dma *pdma)
1291 {
1292 	/*
1293 	 * Mask DMA ring overflow, underflow and
1294 	 * AXI write/read error interrupts
1295 	 */
1296 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1297 		  pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
1298 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1299 		  pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
1300 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1301 		  pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
1302 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1303 		  pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
1304 	iowrite32(XGENE_DMA_INT_ALL_MASK,
1305 		  pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
1306 
1307 	/* Mask DMA error interrupts */
1308 	iowrite32(XGENE_DMA_INT_ALL_MASK, pdma->csr_dma + XGENE_DMA_INT_MASK);
1309 }
1310 
1311 static void xgene_dma_unmask_interrupts(struct xgene_dma *pdma)
1312 {
1313 	/*
1314 	 * Unmask DMA ring overflow, underflow and
1315 	 * AXI write/read error interrupts
1316 	 */
1317 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1318 		  pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
1319 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1320 		  pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
1321 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1322 		  pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
1323 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1324 		  pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
1325 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1326 		  pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
1327 
1328 	/* Unmask DMA error interrupts */
1329 	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
1330 		  pdma->csr_dma + XGENE_DMA_INT_MASK);
1331 }
1332 
1333 static void xgene_dma_init_hw(struct xgene_dma *pdma)
1334 {
1335 	u32 val;
1336 
1337 	/* Associate DMA ring to corresponding ring HW */
1338 	iowrite32(XGENE_DMA_ASSOC_RING_MNGR1,
1339 		  pdma->csr_dma + XGENE_DMA_CFG_RING_WQ_ASSOC);
1340 
1341 	/* Configure RAID6 polynomial control setting */
1342 	if (is_pq_enabled(pdma))
1343 		iowrite32(XGENE_DMA_RAID6_MULTI_CTRL(0x1D),
1344 			  pdma->csr_dma + XGENE_DMA_RAID6_CONT);
1345 	else
1346 		dev_info(pdma->dev, "PQ is disabled in HW\n");
1347 
1348 	xgene_dma_enable(pdma);
1349 	xgene_dma_unmask_interrupts(pdma);
1350 
1351 	/* Get DMA id and version info */
1352 	val = ioread32(pdma->csr_dma + XGENE_DMA_IPBRR);
1353 
1354 	/* DMA device info */
1355 	dev_info(pdma->dev,
1356 		 "X-Gene DMA v%d.%02d.%02d driver registered %d channels",
1357 		 XGENE_DMA_REV_NO_RD(val), XGENE_DMA_BUS_ID_RD(val),
1358 		 XGENE_DMA_DEV_ID_RD(val), XGENE_DMA_MAX_CHANNEL);
1359 }
1360 
1361 static int xgene_dma_init_ring_mngr(struct xgene_dma *pdma)
1362 {
1363 	if (ioread32(pdma->csr_ring + XGENE_DMA_RING_CLKEN) &&
1364 	    (!ioread32(pdma->csr_ring + XGENE_DMA_RING_SRST)))
1365 		return 0;
1366 
1367 	iowrite32(0x3, pdma->csr_ring + XGENE_DMA_RING_CLKEN);
1368 	iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_SRST);
1369 
1370 	/* Bring up memory */
1371 	iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
1372 
1373 	/* Force a barrier */
1374 	ioread32(pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
1375 
1376 	/* reset may take up to 1ms */
1377 	usleep_range(1000, 1100);
1378 
1379 	if (ioread32(pdma->csr_ring + XGENE_DMA_RING_BLK_MEM_RDY)
1380 		!= XGENE_DMA_RING_BLK_MEM_RDY_VAL) {
1381 		dev_err(pdma->dev,
1382 			"Failed to release ring mngr memory from shutdown\n");
1383 		return -ENODEV;
1384 	}
1385 
1386 	/* program threshold set 1 and all hysteresis */
1387 	iowrite32(XGENE_DMA_RING_THRESLD0_SET1_VAL,
1388 		  pdma->csr_ring + XGENE_DMA_RING_THRESLD0_SET1);
1389 	iowrite32(XGENE_DMA_RING_THRESLD1_SET1_VAL,
1390 		  pdma->csr_ring + XGENE_DMA_RING_THRESLD1_SET1);
1391 	iowrite32(XGENE_DMA_RING_HYSTERESIS_VAL,
1392 		  pdma->csr_ring + XGENE_DMA_RING_HYSTERESIS);
1393 
1394 	/* Enable QPcore and assign error queue */
1395 	iowrite32(XGENE_DMA_RING_ENABLE,
1396 		  pdma->csr_ring + XGENE_DMA_RING_CONFIG);
1397 
1398 	return 0;
1399 }
1400 
1401 static int xgene_dma_init_mem(struct xgene_dma *pdma)
1402 {
1403 	int ret;
1404 
1405 	ret = xgene_dma_init_ring_mngr(pdma);
1406 	if (ret)
1407 		return ret;
1408 
1409 	/* Bring up memory */
1410 	iowrite32(0x0, pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
1411 
1412 	/* Force a barrier */
1413 	ioread32(pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
1414 
1415 	/* reset may take up to 1ms */
1416 	usleep_range(1000, 1100);
1417 
1418 	if (ioread32(pdma->csr_dma + XGENE_DMA_BLK_MEM_RDY)
1419 		!= XGENE_DMA_BLK_MEM_RDY_VAL) {
1420 		dev_err(pdma->dev,
1421 			"Failed to release DMA memory from shutdown\n");
1422 		return -ENODEV;
1423 	}
1424 
1425 	return 0;
1426 }
1427 
1428 static int xgene_dma_request_irqs(struct xgene_dma *pdma)
1429 {
1430 	struct xgene_dma_chan *chan;
1431 	int ret, i, j;
1432 
1433 	/* Register DMA error irq */
1434 	ret = devm_request_irq(pdma->dev, pdma->err_irq, xgene_dma_err_isr,
1435 			       0, "dma_error", pdma);
1436 	if (ret) {
1437 		dev_err(pdma->dev,
1438 			"Failed to register error IRQ %d\n", pdma->err_irq);
1439 		return ret;
1440 	}
1441 
1442 	/* Register DMA channel rx irq */
1443 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1444 		chan = &pdma->chan[i];
1445 		irq_set_status_flags(chan->rx_irq, IRQ_DISABLE_UNLAZY);
1446 		ret = devm_request_irq(chan->dev, chan->rx_irq,
1447 				       xgene_dma_chan_ring_isr,
1448 				       0, chan->name, chan);
1449 		if (ret) {
1450 			chan_err(chan, "Failed to register Rx IRQ %d\n",
1451 				 chan->rx_irq);
1452 			devm_free_irq(pdma->dev, pdma->err_irq, pdma);
1453 
1454 			for (j = 0; j < i; j++) {
1455 				chan = &pdma->chan[i];
1456 				irq_clear_status_flags(chan->rx_irq, IRQ_DISABLE_UNLAZY);
1457 				devm_free_irq(chan->dev, chan->rx_irq, chan);
1458 			}
1459 
1460 			return ret;
1461 		}
1462 	}
1463 
1464 	return 0;
1465 }
1466 
1467 static void xgene_dma_free_irqs(struct xgene_dma *pdma)
1468 {
1469 	struct xgene_dma_chan *chan;
1470 	int i;
1471 
1472 	/* Free DMA device error irq */
1473 	devm_free_irq(pdma->dev, pdma->err_irq, pdma);
1474 
1475 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1476 		chan = &pdma->chan[i];
1477 		irq_clear_status_flags(chan->rx_irq, IRQ_DISABLE_UNLAZY);
1478 		devm_free_irq(chan->dev, chan->rx_irq, chan);
1479 	}
1480 }
1481 
1482 static void xgene_dma_set_caps(struct xgene_dma_chan *chan,
1483 			       struct dma_device *dma_dev)
1484 {
1485 	/* Initialize DMA device capability mask */
1486 	dma_cap_zero(dma_dev->cap_mask);
1487 
1488 	/* Set DMA device capability */
1489 
1490 	/* Basically here, the X-Gene SoC DMA engine channel 0 supports XOR
1491 	 * and channel 1 supports XOR, PQ both. First thing here is we have
1492 	 * mechanism in hw to enable/disable PQ/XOR supports on channel 1,
1493 	 * we can make sure this by reading SoC Efuse register.
1494 	 * Second thing, we have hw errata that if we run channel 0 and
1495 	 * channel 1 simultaneously with executing XOR and PQ request,
1496 	 * suddenly DMA engine hangs, So here we enable XOR on channel 0 only
1497 	 * if XOR and PQ supports on channel 1 is disabled.
1498 	 */
1499 	if ((chan->id == XGENE_DMA_PQ_CHANNEL) &&
1500 	    is_pq_enabled(chan->pdma)) {
1501 		dma_cap_set(DMA_PQ, dma_dev->cap_mask);
1502 		dma_cap_set(DMA_XOR, dma_dev->cap_mask);
1503 	} else if ((chan->id == XGENE_DMA_XOR_CHANNEL) &&
1504 		   !is_pq_enabled(chan->pdma)) {
1505 		dma_cap_set(DMA_XOR, dma_dev->cap_mask);
1506 	}
1507 
1508 	/* Set base and prep routines */
1509 	dma_dev->dev = chan->dev;
1510 	dma_dev->device_alloc_chan_resources = xgene_dma_alloc_chan_resources;
1511 	dma_dev->device_free_chan_resources = xgene_dma_free_chan_resources;
1512 	dma_dev->device_issue_pending = xgene_dma_issue_pending;
1513 	dma_dev->device_tx_status = xgene_dma_tx_status;
1514 
1515 	if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
1516 		dma_dev->device_prep_dma_xor = xgene_dma_prep_xor;
1517 		dma_dev->max_xor = XGENE_DMA_MAX_XOR_SRC;
1518 		dma_dev->xor_align = DMAENGINE_ALIGN_64_BYTES;
1519 	}
1520 
1521 	if (dma_has_cap(DMA_PQ, dma_dev->cap_mask)) {
1522 		dma_dev->device_prep_dma_pq = xgene_dma_prep_pq;
1523 		dma_dev->max_pq = XGENE_DMA_MAX_XOR_SRC;
1524 		dma_dev->pq_align = DMAENGINE_ALIGN_64_BYTES;
1525 	}
1526 }
1527 
1528 static int xgene_dma_async_register(struct xgene_dma *pdma, int id)
1529 {
1530 	struct xgene_dma_chan *chan = &pdma->chan[id];
1531 	struct dma_device *dma_dev = &pdma->dma_dev[id];
1532 	int ret;
1533 
1534 	chan->dma_chan.device = dma_dev;
1535 
1536 	spin_lock_init(&chan->lock);
1537 	INIT_LIST_HEAD(&chan->ld_pending);
1538 	INIT_LIST_HEAD(&chan->ld_running);
1539 	INIT_LIST_HEAD(&chan->ld_completed);
1540 	tasklet_init(&chan->tasklet, xgene_dma_tasklet_cb,
1541 		     (unsigned long)chan);
1542 
1543 	chan->pending = 0;
1544 	chan->desc_pool = NULL;
1545 	dma_cookie_init(&chan->dma_chan);
1546 
1547 	/* Setup dma device capabilities and prep routines */
1548 	xgene_dma_set_caps(chan, dma_dev);
1549 
1550 	/* Initialize DMA device list head */
1551 	INIT_LIST_HEAD(&dma_dev->channels);
1552 	list_add_tail(&chan->dma_chan.device_node, &dma_dev->channels);
1553 
1554 	/* Register with Linux async DMA framework*/
1555 	ret = dma_async_device_register(dma_dev);
1556 	if (ret) {
1557 		chan_err(chan, "Failed to register async device %d", ret);
1558 		tasklet_kill(&chan->tasklet);
1559 
1560 		return ret;
1561 	}
1562 
1563 	/* DMA capability info */
1564 	dev_info(pdma->dev,
1565 		 "%s: CAPABILITY ( %s%s)\n", dma_chan_name(&chan->dma_chan),
1566 		 dma_has_cap(DMA_XOR, dma_dev->cap_mask) ? "XOR " : "",
1567 		 dma_has_cap(DMA_PQ, dma_dev->cap_mask) ? "PQ " : "");
1568 
1569 	return 0;
1570 }
1571 
1572 static int xgene_dma_init_async(struct xgene_dma *pdma)
1573 {
1574 	int ret, i, j;
1575 
1576 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL ; i++) {
1577 		ret = xgene_dma_async_register(pdma, i);
1578 		if (ret) {
1579 			for (j = 0; j < i; j++) {
1580 				dma_async_device_unregister(&pdma->dma_dev[j]);
1581 				tasklet_kill(&pdma->chan[j].tasklet);
1582 			}
1583 
1584 			return ret;
1585 		}
1586 	}
1587 
1588 	return ret;
1589 }
1590 
1591 static void xgene_dma_async_unregister(struct xgene_dma *pdma)
1592 {
1593 	int i;
1594 
1595 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
1596 		dma_async_device_unregister(&pdma->dma_dev[i]);
1597 }
1598 
1599 static void xgene_dma_init_channels(struct xgene_dma *pdma)
1600 {
1601 	struct xgene_dma_chan *chan;
1602 	int i;
1603 
1604 	pdma->ring_num = XGENE_DMA_RING_NUM;
1605 
1606 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1607 		chan = &pdma->chan[i];
1608 		chan->dev = pdma->dev;
1609 		chan->pdma = pdma;
1610 		chan->id = i;
1611 		snprintf(chan->name, sizeof(chan->name), "dmachan%d", chan->id);
1612 	}
1613 }
1614 
1615 static int xgene_dma_get_resources(struct platform_device *pdev,
1616 				   struct xgene_dma *pdma)
1617 {
1618 	struct resource *res;
1619 	int irq, i;
1620 
1621 	/* Get DMA csr region */
1622 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1623 	if (!res) {
1624 		dev_err(&pdev->dev, "Failed to get csr region\n");
1625 		return -ENXIO;
1626 	}
1627 
1628 	pdma->csr_dma = devm_ioremap(&pdev->dev, res->start,
1629 				     resource_size(res));
1630 	if (!pdma->csr_dma) {
1631 		dev_err(&pdev->dev, "Failed to ioremap csr region");
1632 		return -ENOMEM;
1633 	}
1634 
1635 	/* Get DMA ring csr region */
1636 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1637 	if (!res) {
1638 		dev_err(&pdev->dev, "Failed to get ring csr region\n");
1639 		return -ENXIO;
1640 	}
1641 
1642 	pdma->csr_ring =  devm_ioremap(&pdev->dev, res->start,
1643 				       resource_size(res));
1644 	if (!pdma->csr_ring) {
1645 		dev_err(&pdev->dev, "Failed to ioremap ring csr region");
1646 		return -ENOMEM;
1647 	}
1648 
1649 	/* Get DMA ring cmd csr region */
1650 	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
1651 	if (!res) {
1652 		dev_err(&pdev->dev, "Failed to get ring cmd csr region\n");
1653 		return -ENXIO;
1654 	}
1655 
1656 	pdma->csr_ring_cmd = devm_ioremap(&pdev->dev, res->start,
1657 					  resource_size(res));
1658 	if (!pdma->csr_ring_cmd) {
1659 		dev_err(&pdev->dev, "Failed to ioremap ring cmd csr region");
1660 		return -ENOMEM;
1661 	}
1662 
1663 	pdma->csr_ring_cmd += XGENE_DMA_RING_CMD_SM_OFFSET;
1664 
1665 	/* Get efuse csr region */
1666 	res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
1667 	if (!res) {
1668 		dev_err(&pdev->dev, "Failed to get efuse csr region\n");
1669 		return -ENXIO;
1670 	}
1671 
1672 	pdma->csr_efuse = devm_ioremap(&pdev->dev, res->start,
1673 				       resource_size(res));
1674 	if (!pdma->csr_efuse) {
1675 		dev_err(&pdev->dev, "Failed to ioremap efuse csr region");
1676 		return -ENOMEM;
1677 	}
1678 
1679 	/* Get DMA error interrupt */
1680 	irq = platform_get_irq(pdev, 0);
1681 	if (irq <= 0) {
1682 		dev_err(&pdev->dev, "Failed to get Error IRQ\n");
1683 		return -ENXIO;
1684 	}
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 			dev_err(&pdev->dev, "Failed to get Rx IRQ\n");
1693 			return -ENXIO;
1694 		}
1695 
1696 		pdma->chan[i - 1].rx_irq = irq;
1697 	}
1698 
1699 	return 0;
1700 }
1701 
1702 static int xgene_dma_probe(struct platform_device *pdev)
1703 {
1704 	struct xgene_dma *pdma;
1705 	int ret, i;
1706 
1707 	pdma = devm_kzalloc(&pdev->dev, sizeof(*pdma), GFP_KERNEL);
1708 	if (!pdma)
1709 		return -ENOMEM;
1710 
1711 	pdma->dev = &pdev->dev;
1712 	platform_set_drvdata(pdev, pdma);
1713 
1714 	ret = xgene_dma_get_resources(pdev, pdma);
1715 	if (ret)
1716 		return ret;
1717 
1718 	pdma->clk = devm_clk_get(&pdev->dev, NULL);
1719 	if (IS_ERR(pdma->clk) && !ACPI_COMPANION(&pdev->dev)) {
1720 		dev_err(&pdev->dev, "Failed to get clk\n");
1721 		return PTR_ERR(pdma->clk);
1722 	}
1723 
1724 	/* Enable clk before accessing registers */
1725 	if (!IS_ERR(pdma->clk)) {
1726 		ret = clk_prepare_enable(pdma->clk);
1727 		if (ret) {
1728 			dev_err(&pdev->dev, "Failed to enable clk %d\n", ret);
1729 			return ret;
1730 		}
1731 	}
1732 
1733 	/* Remove DMA RAM out of shutdown */
1734 	ret = xgene_dma_init_mem(pdma);
1735 	if (ret)
1736 		goto err_clk_enable;
1737 
1738 	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(42));
1739 	if (ret) {
1740 		dev_err(&pdev->dev, "No usable DMA configuration\n");
1741 		goto err_dma_mask;
1742 	}
1743 
1744 	/* Initialize DMA channels software state */
1745 	xgene_dma_init_channels(pdma);
1746 
1747 	/* Configue DMA rings */
1748 	ret = xgene_dma_init_rings(pdma);
1749 	if (ret)
1750 		goto err_clk_enable;
1751 
1752 	ret = xgene_dma_request_irqs(pdma);
1753 	if (ret)
1754 		goto err_request_irq;
1755 
1756 	/* Configure and enable DMA engine */
1757 	xgene_dma_init_hw(pdma);
1758 
1759 	/* Register DMA device with linux async framework */
1760 	ret = xgene_dma_init_async(pdma);
1761 	if (ret)
1762 		goto err_async_init;
1763 
1764 	return 0;
1765 
1766 err_async_init:
1767 	xgene_dma_free_irqs(pdma);
1768 
1769 err_request_irq:
1770 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
1771 		xgene_dma_delete_chan_rings(&pdma->chan[i]);
1772 
1773 err_dma_mask:
1774 err_clk_enable:
1775 	if (!IS_ERR(pdma->clk))
1776 		clk_disable_unprepare(pdma->clk);
1777 
1778 	return ret;
1779 }
1780 
1781 static int xgene_dma_remove(struct platform_device *pdev)
1782 {
1783 	struct xgene_dma *pdma = platform_get_drvdata(pdev);
1784 	struct xgene_dma_chan *chan;
1785 	int i;
1786 
1787 	xgene_dma_async_unregister(pdma);
1788 
1789 	/* Mask interrupts and disable DMA engine */
1790 	xgene_dma_mask_interrupts(pdma);
1791 	xgene_dma_disable(pdma);
1792 	xgene_dma_free_irqs(pdma);
1793 
1794 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
1795 		chan = &pdma->chan[i];
1796 		tasklet_kill(&chan->tasklet);
1797 		xgene_dma_delete_chan_rings(chan);
1798 	}
1799 
1800 	if (!IS_ERR(pdma->clk))
1801 		clk_disable_unprepare(pdma->clk);
1802 
1803 	return 0;
1804 }
1805 
1806 #ifdef CONFIG_ACPI
1807 static const struct acpi_device_id xgene_dma_acpi_match_ptr[] = {
1808 	{"APMC0D43", 0},
1809 	{},
1810 };
1811 MODULE_DEVICE_TABLE(acpi, xgene_dma_acpi_match_ptr);
1812 #endif
1813 
1814 static const struct of_device_id xgene_dma_of_match_ptr[] = {
1815 	{.compatible = "apm,xgene-storm-dma",},
1816 	{},
1817 };
1818 MODULE_DEVICE_TABLE(of, xgene_dma_of_match_ptr);
1819 
1820 static struct platform_driver xgene_dma_driver = {
1821 	.probe = xgene_dma_probe,
1822 	.remove = xgene_dma_remove,
1823 	.driver = {
1824 		.name = "X-Gene-DMA",
1825 		.of_match_table = xgene_dma_of_match_ptr,
1826 		.acpi_match_table = ACPI_PTR(xgene_dma_acpi_match_ptr),
1827 	},
1828 };
1829 
1830 module_platform_driver(xgene_dma_driver);
1831 
1832 MODULE_DESCRIPTION("APM X-Gene SoC DMA driver");
1833 MODULE_AUTHOR("Rameshwar Prasad Sahu <rsahu@apm.com>");
1834 MODULE_AUTHOR("Loc Ho <lho@apm.com>");
1835 MODULE_LICENSE("GPL");
1836 MODULE_VERSION("1.0");
1837