1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Intel MIC Platform Software Stack (MPSS)
4  *
5  * Copyright(c) 2014 Intel Corporation.
6  *
7  * Intel MIC X100 DMA Driver.
8  *
9  * Adapted from IOAT dma driver.
10  */
11 #ifndef _MIC_X100_DMA_H_
12 #define _MIC_X100_DMA_H_
13 
14 #include <linux/kernel.h>
15 #include <linux/delay.h>
16 #include <linux/sched.h>
17 #include <linux/debugfs.h>
18 #include <linux/slab.h>
19 #include <linux/interrupt.h>
20 #include <linux/mic_bus.h>
21 
22 #include "dmaengine.h"
23 
24 /*
25  * MIC has a total of 8 dma channels.
26  * Four channels are assigned for host SW use & the remaining for MIC SW.
27  * MIC DMA transfer size & addresses need to be 64 byte aligned.
28  */
29 #define MIC_DMA_MAX_NUM_CHAN	8
30 #define MIC_DMA_NUM_CHAN	4
31 #define MIC_DMA_ALIGN_SHIFT	DMAENGINE_ALIGN_64_BYTES
32 #define MIC_DMA_ALIGN_BYTES	(1 << MIC_DMA_ALIGN_SHIFT)
33 #define MIC_DMA_DESC_RX_SIZE	(128 * 1024 - 4)
34 
35 /*
36  * Register descriptions
37  * All the registers are 32 bit registers.
38  * DCR is a global register and all others are per-channel.
39  * DCR - bits 0, 2, 4, 6, 8, 10, 12, 14 - enable bits for channels 0 to 7
40  *	 bits 1, 3, 5, 7, 9, 11, 13, 15 - owner bits for channels 0 to 7
41  * DCAR - bit 24 & 25 interrupt masks for mic owned & host owned channels
42  * DHPR - head of the descriptor ring updated by s/w
43  * DTPR - tail of the descriptor ring updated by h/w
44  * DRAR_LO - lower 32 bits of descriptor ring's mic address
45  * DRAR_HI - 3:0 - remaining 4 bits of descriptor ring's mic address
46  *	     20:4 descriptor ring size
47  *	     25:21 mic smpt entry number
48  * DSTAT - 16:0 h/w completion count; 31:28 dma engine status
49  * DCHERR - this register is non-zero on error
50  * DCHERRMSK - interrupt mask register
51  */
52 #define MIC_DMA_HW_CMP_CNT_MASK		0x1ffff
53 #define MIC_DMA_CHAN_QUIESCE		0x20000000
54 #define MIC_DMA_SBOX_BASE		0x00010000
55 #define MIC_DMA_SBOX_DCR		0x0000A280
56 #define MIC_DMA_SBOX_CH_BASE		0x0001A000
57 #define MIC_DMA_SBOX_CHAN_OFF		0x40
58 #define MIC_DMA_SBOX_DCAR_IM0		(0x1 << 24)
59 #define MIC_DMA_SBOX_DCAR_IM1		(0x1 << 25)
60 #define MIC_DMA_SBOX_DRARHI_SYS_MASK	(0x1 << 26)
61 #define MIC_DMA_REG_DCAR		0
62 #define MIC_DMA_REG_DHPR		4
63 #define MIC_DMA_REG_DTPR		8
64 #define MIC_DMA_REG_DRAR_LO		20
65 #define MIC_DMA_REG_DRAR_HI		24
66 #define MIC_DMA_REG_DSTAT		32
67 #define MIC_DMA_REG_DCHERR		44
68 #define MIC_DMA_REG_DCHERRMSK		48
69 
70 /* HW dma desc */
71 struct mic_dma_desc {
72 	u64 qw0;
73 	u64 qw1;
74 };
75 
76 enum mic_dma_chan_owner {
77 	MIC_DMA_CHAN_MIC = 0,
78 	MIC_DMA_CHAN_HOST
79 };
80 
81 /*
82  * mic_dma_chan - channel specific information
83  * @ch_num: channel number
84  * @owner: owner of this channel
85  * @last_tail: cached value of descriptor ring tail
86  * @head: index of next descriptor in desc_ring
87  * @issued: hardware notification point
88  * @submitted: index that will be used to submit descriptors to h/w
89  * @api_ch: dma engine api channel
90  * @desc_ring: dma descriptor ring
91  * @desc_ring_micpa: mic physical address of desc_ring
92  * @status_dest: destination for status (fence) descriptor
93  * @status_dest_micpa: mic address for status_dest,
94  *		       DMA controller uses this address
95  * @tx_array: array of async_tx
96  * @cleanup_lock: lock held when processing completed tx
97  * @prep_lock: lock held in prep_memcpy & released in tx_submit
98  * @issue_lock: lock used to synchronize writes to head
99  * @cookie: mic_irq cookie used with mic irq request
100  */
101 struct mic_dma_chan {
102 	int ch_num;
103 	enum mic_dma_chan_owner owner;
104 	u32 last_tail;
105 	u32 head;
106 	u32 issued;
107 	u32 submitted;
108 	struct dma_chan api_ch;
109 	struct mic_dma_desc *desc_ring;
110 	dma_addr_t desc_ring_micpa;
111 	u64 *status_dest;
112 	dma_addr_t status_dest_micpa;
113 	struct dma_async_tx_descriptor *tx_array;
114 	spinlock_t cleanup_lock;
115 	spinlock_t prep_lock;
116 	spinlock_t issue_lock;
117 	struct mic_irq *cookie;
118 };
119 
120 /*
121  * struct mic_dma_device - per mic device
122  * @mic_ch: dma channels
123  * @dma_dev: underlying dma device
124  * @mbdev: mic bus dma device
125  * @mmio: virtual address of the mmio space
126  * @dbg_dir: debugfs directory
127  * @start_ch: first channel number that can be used
128  * @max_xfer_size: maximum transfer size per dma descriptor
129  */
130 struct mic_dma_device {
131 	struct mic_dma_chan mic_ch[MIC_DMA_MAX_NUM_CHAN];
132 	struct dma_device dma_dev;
133 	struct mbus_device *mbdev;
134 	void __iomem *mmio;
135 	struct dentry *dbg_dir;
136 	int start_ch;
137 	size_t max_xfer_size;
138 };
139 
to_mic_dma_chan(struct dma_chan * ch)140 static inline struct mic_dma_chan *to_mic_dma_chan(struct dma_chan *ch)
141 {
142 	return container_of(ch, struct mic_dma_chan, api_ch);
143 }
144 
to_mic_dma_dev(struct mic_dma_chan * ch)145 static inline struct mic_dma_device *to_mic_dma_dev(struct mic_dma_chan *ch)
146 {
147 	return
148 	container_of((const typeof(((struct mic_dma_device *)0)->mic_ch)*)
149 		     (ch - ch->ch_num), struct mic_dma_device, mic_ch);
150 }
151 
to_mbus_device(struct mic_dma_chan * ch)152 static inline struct mbus_device *to_mbus_device(struct mic_dma_chan *ch)
153 {
154 	return to_mic_dma_dev(ch)->mbdev;
155 }
156 
to_mbus_hw_ops(struct mic_dma_chan * ch)157 static inline struct mbus_hw_ops *to_mbus_hw_ops(struct mic_dma_chan *ch)
158 {
159 	return to_mbus_device(ch)->hw_ops;
160 }
161 
mic_dma_ch_to_device(struct mic_dma_chan * ch)162 static inline struct device *mic_dma_ch_to_device(struct mic_dma_chan *ch)
163 {
164 	return to_mic_dma_dev(ch)->dma_dev.dev;
165 }
166 
mic_dma_chan_to_mmio(struct mic_dma_chan * ch)167 static inline void __iomem *mic_dma_chan_to_mmio(struct mic_dma_chan *ch)
168 {
169 	return to_mic_dma_dev(ch)->mmio;
170 }
171 
mic_dma_read_reg(struct mic_dma_chan * ch,u32 reg)172 static inline u32 mic_dma_read_reg(struct mic_dma_chan *ch, u32 reg)
173 {
174 	return ioread32(mic_dma_chan_to_mmio(ch) + MIC_DMA_SBOX_CH_BASE +
175 			ch->ch_num * MIC_DMA_SBOX_CHAN_OFF + reg);
176 }
177 
mic_dma_write_reg(struct mic_dma_chan * ch,u32 reg,u32 val)178 static inline void mic_dma_write_reg(struct mic_dma_chan *ch, u32 reg, u32 val)
179 {
180 	iowrite32(val, mic_dma_chan_to_mmio(ch) + MIC_DMA_SBOX_CH_BASE +
181 		  ch->ch_num * MIC_DMA_SBOX_CHAN_OFF + reg);
182 }
183 
mic_dma_mmio_read(struct mic_dma_chan * ch,u32 offset)184 static inline u32 mic_dma_mmio_read(struct mic_dma_chan *ch, u32 offset)
185 {
186 	return ioread32(mic_dma_chan_to_mmio(ch) + offset);
187 }
188 
mic_dma_mmio_write(struct mic_dma_chan * ch,u32 val,u32 offset)189 static inline void mic_dma_mmio_write(struct mic_dma_chan *ch, u32 val,
190 				      u32 offset)
191 {
192 	iowrite32(val, mic_dma_chan_to_mmio(ch) + offset);
193 }
194 
mic_dma_read_cmp_cnt(struct mic_dma_chan * ch)195 static inline u32 mic_dma_read_cmp_cnt(struct mic_dma_chan *ch)
196 {
197 	return mic_dma_read_reg(ch, MIC_DMA_REG_DSTAT) &
198 	       MIC_DMA_HW_CMP_CNT_MASK;
199 }
200 
mic_dma_chan_set_owner(struct mic_dma_chan * ch)201 static inline void mic_dma_chan_set_owner(struct mic_dma_chan *ch)
202 {
203 	u32 dcr = mic_dma_mmio_read(ch, MIC_DMA_SBOX_BASE + MIC_DMA_SBOX_DCR);
204 	u32 chan_num = ch->ch_num;
205 
206 	dcr = (dcr & ~(0x1 << (chan_num * 2))) | (ch->owner << (chan_num * 2));
207 	mic_dma_mmio_write(ch, dcr, MIC_DMA_SBOX_BASE + MIC_DMA_SBOX_DCR);
208 }
209 
mic_dma_enable_chan(struct mic_dma_chan * ch)210 static inline void mic_dma_enable_chan(struct mic_dma_chan *ch)
211 {
212 	u32 dcr = mic_dma_mmio_read(ch, MIC_DMA_SBOX_BASE + MIC_DMA_SBOX_DCR);
213 
214 	dcr |= 2 << (ch->ch_num << 1);
215 	mic_dma_mmio_write(ch, dcr, MIC_DMA_SBOX_BASE + MIC_DMA_SBOX_DCR);
216 }
217 
mic_dma_disable_chan(struct mic_dma_chan * ch)218 static inline void mic_dma_disable_chan(struct mic_dma_chan *ch)
219 {
220 	u32 dcr = mic_dma_mmio_read(ch, MIC_DMA_SBOX_BASE + MIC_DMA_SBOX_DCR);
221 
222 	dcr &= ~(2 << (ch->ch_num << 1));
223 	mic_dma_mmio_write(ch, dcr, MIC_DMA_SBOX_BASE + MIC_DMA_SBOX_DCR);
224 }
225 
mic_dma_chan_set_desc_ring(struct mic_dma_chan * ch)226 static void mic_dma_chan_set_desc_ring(struct mic_dma_chan *ch)
227 {
228 	u32 drar_hi;
229 	dma_addr_t desc_ring_micpa = ch->desc_ring_micpa;
230 
231 	drar_hi = (MIC_DMA_DESC_RX_SIZE & 0x1ffff) << 4;
232 	if (MIC_DMA_CHAN_MIC == ch->owner) {
233 		drar_hi |= (desc_ring_micpa >> 32) & 0xf;
234 	} else {
235 		drar_hi |= MIC_DMA_SBOX_DRARHI_SYS_MASK;
236 		drar_hi |= ((desc_ring_micpa >> 34)
237 			    & 0x1f) << 21;
238 		drar_hi |= (desc_ring_micpa >> 32) & 0x3;
239 	}
240 	mic_dma_write_reg(ch, MIC_DMA_REG_DRAR_LO, (u32) desc_ring_micpa);
241 	mic_dma_write_reg(ch, MIC_DMA_REG_DRAR_HI, drar_hi);
242 }
243 
mic_dma_chan_mask_intr(struct mic_dma_chan * ch)244 static inline void mic_dma_chan_mask_intr(struct mic_dma_chan *ch)
245 {
246 	u32 dcar = mic_dma_read_reg(ch, MIC_DMA_REG_DCAR);
247 
248 	if (MIC_DMA_CHAN_MIC == ch->owner)
249 		dcar |= MIC_DMA_SBOX_DCAR_IM0;
250 	else
251 		dcar |= MIC_DMA_SBOX_DCAR_IM1;
252 	mic_dma_write_reg(ch, MIC_DMA_REG_DCAR, dcar);
253 }
254 
mic_dma_chan_unmask_intr(struct mic_dma_chan * ch)255 static inline void mic_dma_chan_unmask_intr(struct mic_dma_chan *ch)
256 {
257 	u32 dcar = mic_dma_read_reg(ch, MIC_DMA_REG_DCAR);
258 
259 	if (MIC_DMA_CHAN_MIC == ch->owner)
260 		dcar &= ~MIC_DMA_SBOX_DCAR_IM0;
261 	else
262 		dcar &= ~MIC_DMA_SBOX_DCAR_IM1;
263 	mic_dma_write_reg(ch, MIC_DMA_REG_DCAR, dcar);
264 }
265 
mic_dma_ack_interrupt(struct mic_dma_chan * ch)266 static void mic_dma_ack_interrupt(struct mic_dma_chan *ch)
267 {
268 	if (MIC_DMA_CHAN_MIC == ch->owner) {
269 		/* HW errata */
270 		mic_dma_chan_mask_intr(ch);
271 		mic_dma_chan_unmask_intr(ch);
272 	}
273 	to_mbus_hw_ops(ch)->ack_interrupt(to_mbus_device(ch), ch->ch_num);
274 }
275 #endif
276