summaryrefslogtreecommitdiff
path: root/drivers/net/ethernet/sfc/io.h
blob: 4d3f119b67b38ec35719ebac40d59f49ea9b844f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
/****************************************************************************
 * Driver for Solarflare network controllers and boards
 * Copyright 2005-2006 Fen Systems Ltd.
 * Copyright 2006-2013 Solarflare Communications Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation, incorporated herein by reference.
 */

#ifndef EFX_IO_H
#define EFX_IO_H

#include <linux/io.h>
#include <linux/spinlock.h>

/**************************************************************************
 *
 * NIC register I/O
 *
 **************************************************************************
 *
 * Notes on locking strategy for the Falcon architecture:
 *
 * Many CSRs are very wide and cannot be read or written atomically.
 * Writes from the host are buffered by the Bus Interface Unit (BIU)
 * up to 128 bits.  Whenever the host writes part of such a register,
 * the BIU collects the written value and does not write to the
 * underlying register until all 4 dwords have been written.  A
 * similar buffering scheme applies to host access to the NIC's 64-bit
 * SRAM.
 *
 * Writes to different CSRs and 64-bit SRAM words must be serialised,
 * since interleaved access can result in lost writes.  We use
 * efx_nic::biu_lock for this.
 *
 * We also serialise reads from 128-bit CSRs and SRAM with the same
 * spinlock.  This may not be necessary, but it doesn't really matter
 * as there are no such reads on the fast path.
 *
 * The DMA descriptor pointers (RX_DESC_UPD and TX_DESC_UPD) are
 * 128-bit but are special-cased in the BIU to avoid the need for
 * locking in the host:
 *
 * - They are write-only.
 * - The semantics of writing to these registers are such that
 *   replacing the low 96 bits with zero does not affect functionality.
 * - If the host writes to the last dword address of such a register
 *   (i.e. the high 32 bits) the underlying register will always be
 *   written.  If the collector and the current write together do not
 *   provide values for all 128 bits of the register, the low 96 bits
 *   will be written as zero.
 * - If the host writes to the address of any other part of such a
 *   register while the collector already holds values for some other
 *   register, the write is discarded and the collector maintains its
 *   current state.
 *
 * The EF10 architecture exposes very few registers to the host and
 * most of them are only 32 bits wide.  The only exceptions are the MC
 * doorbell register pair, which has its own latching, and
 * TX_DESC_UPD, which works in a similar way to the Falcon
 * architecture.
 */

#if BITS_PER_LONG == 64
#define EFX_USE_QWORD_IO 1
#endif

/* PIO is a win only if write-combining is possible */
#ifdef ARCH_HAS_IOREMAP_WC
#define EFX_USE_PIO 1
#endif

#ifdef EFX_USE_QWORD_IO
static inline void _efx_writeq(struct efx_nic *efx, __le64 value,
				  unsigned int reg)
{
	__raw_writeq((__force u64)value, efx->membase + reg);
}
static inline __le64 _efx_readq(struct efx_nic *efx, unsigned int reg)
{
	return (__force __le64)__raw_readq(efx->membase + reg);
}
#endif

static inline void _efx_writed(struct efx_nic *efx, __le32 value,
				  unsigned int reg)
{
	__raw_writel((__force u32)value, efx->membase + reg);
}
static inline __le32 _efx_readd(struct efx_nic *efx, unsigned int reg)
{
	return (__force __le32)__raw_readl(efx->membase + reg);
}

/* Write a normal 128-bit CSR, locking as appropriate. */
static inline void efx_writeo(struct efx_nic *efx, const efx_oword_t *value,
			      unsigned int reg)
{
	unsigned long flags __attribute__ ((unused));

	netif_vdbg(efx, hw, efx->net_dev,
		   "writing register %x with " EFX_OWORD_FMT "\n", reg,
		   EFX_OWORD_VAL(*value));

	spin_lock_irqsave(&efx->biu_lock, flags);
#ifdef EFX_USE_QWORD_IO
	_efx_writeq(efx, value->u64[0], reg + 0);
	_efx_writeq(efx, value->u64[1], reg + 8);
#else
	_efx_writed(efx, value->u32[0], reg + 0);
	_efx_writed(efx, value->u32[1], reg + 4);
	_efx_writed(efx, value->u32[2], reg + 8);
	_efx_writed(efx, value->u32[3], reg + 12);
#endif
	mmiowb();
	spin_unlock_irqrestore(&efx->biu_lock, flags);
}

/* Write 64-bit SRAM through the supplied mapping, locking as appropriate. */
static inline void efx_sram_writeq(struct efx_nic *efx, void __iomem *membase,
				   const efx_qword_t *value, unsigned int index)
{
	unsigned int addr = index * sizeof(*value);
	unsigned long flags __attribute__ ((unused));

	netif_vdbg(efx, hw, efx->net_dev,
		   "writing SRAM address %x with " EFX_QWORD_FMT "\n",
		   addr, EFX_QWORD_VAL(*value));

	spin_lock_irqsave(&efx->biu_lock, flags);
#ifdef EFX_USE_QWORD_IO
	__raw_writeq((__force u64)value->u64[0], membase + addr);
#else
	__raw_writel((__force u32)value->u32[0], membase + addr);
	__raw_writel((__force u32)value->u32[1], membase + addr + 4);
#endif
	mmiowb();
	spin_unlock_irqrestore(&efx->biu_lock, flags);
}

/* Write a 32-bit CSR or the last dword of a special 128-bit CSR */
static inline void efx_writed(struct efx_nic *efx, const efx_dword_t *value,
			      unsigned int reg)
{
	netif_vdbg(efx, hw, efx->net_dev,
		   "writing register %x with "EFX_DWORD_FMT"\n",
		   reg, EFX_DWORD_VAL(*value));

	/* No lock required */
	_efx_writed(efx, value->u32[0], reg);
}

/* Read a 128-bit CSR, locking as appropriate. */
static inline void efx_reado(struct efx_nic *efx, efx_oword_t *value,
			     unsigned int reg)
{
	unsigned long flags __attribute__ ((unused));

	spin_lock_irqsave(&efx->biu_lock, flags);
	value->u32[0] = _efx_readd(efx, reg + 0);
	value->u32[1] = _efx_readd(efx, reg + 4);
	value->u32[2] = _efx_readd(efx, reg + 8);
	value->u32[3] = _efx_readd(efx, reg + 12);
	spin_unlock_irqrestore(&efx->biu_lock, flags);

	netif_vdbg(efx, hw, efx->net_dev,
		   "read from register %x, got " EFX_OWORD_FMT "\n", reg,
		   EFX_OWORD_VAL(*value));
}

/* Read 64-bit SRAM through the supplied mapping, locking as appropriate. */
static inline void efx_sram_readq(struct efx_nic *efx, void __iomem *membase,
				  efx_qword_t *value, unsigned int index)
{
	unsigned int addr = index * sizeof(*value);
	unsigned long flags __attribute__ ((unused));

	spin_lock_irqsave(&efx->biu_lock, flags);
#ifdef EFX_USE_QWORD_IO
	value->u64[0] = (__force __le64)__raw_readq(membase + addr);
#else
	value->u32[0] = (__force __le32)__raw_readl(membase + addr);
	value->u32[1] = (__force __le32)__raw_readl(membase + addr + 4);
#endif
	spin_unlock_irqrestore(&efx->biu_lock, flags);

	netif_vdbg(efx, hw, efx->net_dev,
		   "read from SRAM address %x, got "EFX_QWORD_FMT"\n",
		   addr, EFX_QWORD_VAL(*value));
}

/* Read a 32-bit CSR or SRAM */
static inline void efx_readd(struct efx_nic *efx, efx_dword_t *value,
				unsigned int reg)
{
	value->u32[0] = _efx_readd(efx, reg);
	netif_vdbg(efx, hw, efx->net_dev,
		   "read from register %x, got "EFX_DWORD_FMT"\n",
		   reg, EFX_DWORD_VAL(*value));
}

/* Write a 128-bit CSR forming part of a table */
static inline void
efx_writeo_table(struct efx_nic *efx, const efx_oword_t *value,
		 unsigned int reg, unsigned int index)
{
	efx_writeo(efx, value, reg + index * sizeof(efx_oword_t));
}

/* Read a 128-bit CSR forming part of a table */
static inline void efx_reado_table(struct efx_nic *efx, efx_oword_t *value,
				     unsigned int reg, unsigned int index)
{
	efx_reado(efx, value, reg + index * sizeof(efx_oword_t));
}

/* Page size used as step between per-VI registers */
#define EFX_VI_PAGE_SIZE 0x2000

/* Calculate offset to page-mapped register */
#define EFX_PAGED_REG(page, reg) \
	((page) * EFX_VI_PAGE_SIZE + (reg))

/* Write the whole of RX_DESC_UPD or TX_DESC_UPD */
static inline void _efx_writeo_page(struct efx_nic *efx, efx_oword_t *value,
				    unsigned int reg, unsigned int page)
{
	reg = EFX_PAGED_REG(page, reg);

	netif_vdbg(efx, hw, efx->net_dev,
		   "writing register %x with " EFX_OWORD_FMT "\n", reg,
		   EFX_OWORD_VAL(*value));

#ifdef EFX_USE_QWORD_IO
	_efx_writeq(efx, value->u64[0], reg + 0);
	_efx_writeq(efx, value->u64[1], reg + 8);
#else
	_efx_writed(efx, value->u32[0], reg + 0);
	_efx_writed(efx, value->u32[1], reg + 4);
	_efx_writed(efx, value->u32[2], reg + 8);
	_efx_writed(efx, value->u32[3], reg + 12);
#endif
}
#define efx_writeo_page(efx, value, reg, page)				\
	_efx_writeo_page(efx, value,					\
			 reg +						\
			 BUILD_BUG_ON_ZERO((reg) != 0x830 && (reg) != 0xa10), \
			 page)

/* Write a page-mapped 32-bit CSR (EVQ_RPTR, EVQ_TMR (EF10), or the
 * high bits of RX_DESC_UPD or TX_DESC_UPD)
 */
static inline void
_efx_writed_page(struct efx_nic *efx, const efx_dword_t *value,
		 unsigned int reg, unsigned int page)
{
	efx_writed(efx, value, EFX_PAGED_REG(page, reg));
}
#define efx_writed_page(efx, value, reg, page)				\
	_efx_writed_page(efx, value,					\
			 reg +						\
			 BUILD_BUG_ON_ZERO((reg) != 0x400 &&		\
					   (reg) != 0x420 &&		\
					   (reg) != 0x830 &&		\
					   (reg) != 0x83c &&		\
					   (reg) != 0xa18 &&		\
					   (reg) != 0xa1c),		\
			 page)

/* Write TIMER_COMMAND.  This is a page-mapped 32-bit CSR, but a bug
 * in the BIU means that writes to TIMER_COMMAND[0] invalidate the
 * collector register.
 */
static inline void _efx_writed_page_locked(struct efx_nic *efx,
					   const efx_dword_t *value,
					   unsigned int reg,
					   unsigned int page)
{
	unsigned long flags __attribute__ ((unused));

	if (page == 0) {
		spin_lock_irqsave(&efx->biu_lock, flags);
		efx_writed(efx, value, EFX_PAGED_REG(page, reg));
		spin_unlock_irqrestore(&efx->biu_lock, flags);
	} else {
		efx_writed(efx, value, EFX_PAGED_REG(page, reg));
	}
}
#define efx_writed_page_locked(efx, value, reg, page)			\
	_efx_writed_page_locked(efx, value,				\
				reg + BUILD_BUG_ON_ZERO((reg) != 0x420), \
				page)

#endif /* EFX_IO_H */