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1 | /**************************************************************************** |
2 | * Driver for Solarflare Solarstorm network controllers and boards | |
3 | * Copyright 2005-2006 Fen Systems Ltd. | |
4 | * Copyright 2006-2008 Solarflare Communications Inc. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License version 2 as published | |
8 | * by the Free Software Foundation, incorporated herein by reference. | |
9 | */ | |
10 | ||
11 | #ifndef EFX_FALCON_IO_H | |
12 | #define EFX_FALCON_IO_H | |
13 | ||
14 | #include <linux/io.h> | |
15 | #include <linux/spinlock.h> | |
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16 | |
17 | /************************************************************************** | |
18 | * | |
19 | * Falcon hardware access | |
20 | * | |
21 | ************************************************************************** | |
22 | * | |
23 | * Notes on locking strategy: | |
24 | * | |
25 | * Most Falcon registers require 16-byte (or 8-byte, for SRAM | |
26 | * registers) atomic writes which necessitates locking. | |
27 | * Under normal operation few writes to the Falcon BAR are made and these | |
28 | * registers (EVQ_RPTR_REG, RX_DESC_UPD_REG and TX_DESC_UPD_REG) are special | |
29 | * cased to allow 4-byte (hence lockless) accesses. | |
30 | * | |
31 | * It *is* safe to write to these 4-byte registers in the middle of an | |
32 | * access to an 8-byte or 16-byte register. We therefore use a | |
33 | * spinlock to protect accesses to the larger registers, but no locks | |
34 | * for the 4-byte registers. | |
35 | * | |
36 | * A write barrier is needed to ensure that DW3 is written after DW0/1/2 | |
37 | * due to the way the 16byte registers are "collected" in the Falcon BIU | |
38 | * | |
39 | * We also lock when carrying out reads, to ensure consistency of the | |
40 | * data (made possible since the BIU reads all 128 bits into a cache). | |
41 | * Reads are very rare, so this isn't a significant performance | |
42 | * impact. (Most data transferred from NIC to host is DMAed directly | |
43 | * into host memory). | |
44 | * | |
45 | * I/O BAR access uses locks for both reads and writes (but is only provided | |
46 | * for testing purposes). | |
47 | */ | |
48 | ||
49 | /* Special buffer descriptors (Falcon SRAM) */ | |
50 | #define BUF_TBL_KER_A1 0x18000 | |
51 | #define BUF_TBL_KER_B0 0x800000 | |
52 | ||
53 | ||
54 | #if BITS_PER_LONG == 64 | |
55 | #define FALCON_USE_QWORD_IO 1 | |
56 | #endif | |
57 | ||
55668611 BH |
58 | #ifdef FALCON_USE_QWORD_IO |
59 | static inline void _falcon_writeq(struct efx_nic *efx, __le64 value, | |
60 | unsigned int reg) | |
61 | { | |
62 | __raw_writeq((__force u64)value, efx->membase + reg); | |
63 | } | |
64 | static inline __le64 _falcon_readq(struct efx_nic *efx, unsigned int reg) | |
65 | { | |
66 | return (__force __le64)__raw_readq(efx->membase + reg); | |
67 | } | |
68 | #endif | |
69 | ||
70 | static inline void _falcon_writel(struct efx_nic *efx, __le32 value, | |
71 | unsigned int reg) | |
72 | { | |
73 | __raw_writel((__force u32)value, efx->membase + reg); | |
74 | } | |
75 | static inline __le32 _falcon_readl(struct efx_nic *efx, unsigned int reg) | |
76 | { | |
77 | return (__force __le32)__raw_readl(efx->membase + reg); | |
78 | } | |
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79 | |
80 | /* Writes to a normal 16-byte Falcon register, locking as appropriate. */ | |
81 | static inline void falcon_write(struct efx_nic *efx, efx_oword_t *value, | |
82 | unsigned int reg) | |
83 | { | |
84 | unsigned long flags; | |
85 | ||
86 | EFX_REGDUMP(efx, "writing register %x with " EFX_OWORD_FMT "\n", reg, | |
87 | EFX_OWORD_VAL(*value)); | |
88 | ||
89 | spin_lock_irqsave(&efx->biu_lock, flags); | |
90 | #ifdef FALCON_USE_QWORD_IO | |
91 | _falcon_writeq(efx, value->u64[0], reg + 0); | |
92 | wmb(); | |
93 | _falcon_writeq(efx, value->u64[1], reg + 8); | |
94 | #else | |
95 | _falcon_writel(efx, value->u32[0], reg + 0); | |
96 | _falcon_writel(efx, value->u32[1], reg + 4); | |
97 | _falcon_writel(efx, value->u32[2], reg + 8); | |
98 | wmb(); | |
99 | _falcon_writel(efx, value->u32[3], reg + 12); | |
100 | #endif | |
101 | mmiowb(); | |
102 | spin_unlock_irqrestore(&efx->biu_lock, flags); | |
103 | } | |
104 | ||
105 | /* Writes to an 8-byte Falcon SRAM register, locking as appropriate. */ | |
106 | static inline void falcon_write_sram(struct efx_nic *efx, efx_qword_t *value, | |
107 | unsigned int index) | |
108 | { | |
109 | unsigned int reg = efx->type->buf_tbl_base + (index * sizeof(*value)); | |
110 | unsigned long flags; | |
111 | ||
112 | EFX_REGDUMP(efx, "writing SRAM register %x with " EFX_QWORD_FMT "\n", | |
113 | reg, EFX_QWORD_VAL(*value)); | |
114 | ||
115 | spin_lock_irqsave(&efx->biu_lock, flags); | |
116 | #ifdef FALCON_USE_QWORD_IO | |
117 | _falcon_writeq(efx, value->u64[0], reg + 0); | |
118 | #else | |
119 | _falcon_writel(efx, value->u32[0], reg + 0); | |
120 | wmb(); | |
121 | _falcon_writel(efx, value->u32[1], reg + 4); | |
122 | #endif | |
123 | mmiowb(); | |
124 | spin_unlock_irqrestore(&efx->biu_lock, flags); | |
125 | } | |
126 | ||
127 | /* Write dword to Falcon register that allows partial writes | |
128 | * | |
129 | * Some Falcon registers (EVQ_RPTR_REG, RX_DESC_UPD_REG and | |
130 | * TX_DESC_UPD_REG) can be written to as a single dword. This allows | |
131 | * for lockless writes. | |
132 | */ | |
133 | static inline void falcon_writel(struct efx_nic *efx, efx_dword_t *value, | |
134 | unsigned int reg) | |
135 | { | |
136 | EFX_REGDUMP(efx, "writing partial register %x with "EFX_DWORD_FMT"\n", | |
137 | reg, EFX_DWORD_VAL(*value)); | |
138 | ||
139 | /* No lock required */ | |
140 | _falcon_writel(efx, value->u32[0], reg); | |
141 | } | |
142 | ||
143 | /* Read from a Falcon register | |
144 | * | |
145 | * This reads an entire 16-byte Falcon register in one go, locking as | |
146 | * appropriate. It is essential to read the first dword first, as this | |
147 | * prompts Falcon to load the current value into the shadow register. | |
148 | */ | |
149 | static inline void falcon_read(struct efx_nic *efx, efx_oword_t *value, | |
150 | unsigned int reg) | |
151 | { | |
152 | unsigned long flags; | |
153 | ||
154 | spin_lock_irqsave(&efx->biu_lock, flags); | |
155 | value->u32[0] = _falcon_readl(efx, reg + 0); | |
156 | rmb(); | |
157 | value->u32[1] = _falcon_readl(efx, reg + 4); | |
158 | value->u32[2] = _falcon_readl(efx, reg + 8); | |
159 | value->u32[3] = _falcon_readl(efx, reg + 12); | |
160 | spin_unlock_irqrestore(&efx->biu_lock, flags); | |
161 | ||
162 | EFX_REGDUMP(efx, "read from register %x, got " EFX_OWORD_FMT "\n", reg, | |
163 | EFX_OWORD_VAL(*value)); | |
164 | } | |
165 | ||
166 | /* This reads an 8-byte Falcon SRAM entry in one go. */ | |
167 | static inline void falcon_read_sram(struct efx_nic *efx, efx_qword_t *value, | |
168 | unsigned int index) | |
169 | { | |
170 | unsigned int reg = efx->type->buf_tbl_base + (index * sizeof(*value)); | |
171 | unsigned long flags; | |
172 | ||
173 | spin_lock_irqsave(&efx->biu_lock, flags); | |
174 | #ifdef FALCON_USE_QWORD_IO | |
175 | value->u64[0] = _falcon_readq(efx, reg + 0); | |
176 | #else | |
177 | value->u32[0] = _falcon_readl(efx, reg + 0); | |
178 | rmb(); | |
179 | value->u32[1] = _falcon_readl(efx, reg + 4); | |
180 | #endif | |
181 | spin_unlock_irqrestore(&efx->biu_lock, flags); | |
182 | ||
183 | EFX_REGDUMP(efx, "read from SRAM register %x, got "EFX_QWORD_FMT"\n", | |
184 | reg, EFX_QWORD_VAL(*value)); | |
185 | } | |
186 | ||
187 | /* Read dword from Falcon register that allows partial writes (sic) */ | |
188 | static inline void falcon_readl(struct efx_nic *efx, efx_dword_t *value, | |
189 | unsigned int reg) | |
190 | { | |
191 | value->u32[0] = _falcon_readl(efx, reg); | |
192 | EFX_REGDUMP(efx, "read from register %x, got "EFX_DWORD_FMT"\n", | |
193 | reg, EFX_DWORD_VAL(*value)); | |
194 | } | |
195 | ||
196 | /* Write to a register forming part of a table */ | |
197 | static inline void falcon_write_table(struct efx_nic *efx, efx_oword_t *value, | |
198 | unsigned int reg, unsigned int index) | |
199 | { | |
200 | falcon_write(efx, value, reg + index * sizeof(efx_oword_t)); | |
201 | } | |
202 | ||
203 | /* Read to a register forming part of a table */ | |
204 | static inline void falcon_read_table(struct efx_nic *efx, efx_oword_t *value, | |
205 | unsigned int reg, unsigned int index) | |
206 | { | |
207 | falcon_read(efx, value, reg + index * sizeof(efx_oword_t)); | |
208 | } | |
209 | ||
210 | /* Write to a dword register forming part of a table */ | |
211 | static inline void falcon_writel_table(struct efx_nic *efx, efx_dword_t *value, | |
212 | unsigned int reg, unsigned int index) | |
213 | { | |
214 | falcon_writel(efx, value, reg + index * sizeof(efx_oword_t)); | |
215 | } | |
216 | ||
217 | /* Page-mapped register block size */ | |
218 | #define FALCON_PAGE_BLOCK_SIZE 0x2000 | |
219 | ||
220 | /* Calculate offset to page-mapped register block */ | |
221 | #define FALCON_PAGED_REG(page, reg) \ | |
222 | ((page) * FALCON_PAGE_BLOCK_SIZE + (reg)) | |
223 | ||
224 | /* As for falcon_write(), but for a page-mapped register. */ | |
225 | static inline void falcon_write_page(struct efx_nic *efx, efx_oword_t *value, | |
226 | unsigned int reg, unsigned int page) | |
227 | { | |
228 | falcon_write(efx, value, FALCON_PAGED_REG(page, reg)); | |
229 | } | |
230 | ||
231 | /* As for falcon_writel(), but for a page-mapped register. */ | |
232 | static inline void falcon_writel_page(struct efx_nic *efx, efx_dword_t *value, | |
233 | unsigned int reg, unsigned int page) | |
234 | { | |
235 | falcon_writel(efx, value, FALCON_PAGED_REG(page, reg)); | |
236 | } | |
237 | ||
238 | /* Write dword to Falcon page-mapped register with an extra lock. | |
239 | * | |
240 | * As for falcon_writel_page(), but for a register that suffers from | |
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241 | * SFC bug 3181. If writing to page 0, take out a lock so the BIU |
242 | * collector cannot be confused. | |
243 | */ | |
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244 | static inline void falcon_writel_page_locked(struct efx_nic *efx, |
245 | efx_dword_t *value, | |
246 | unsigned int reg, | |
247 | unsigned int page) | |
248 | { | |
85451a95 | 249 | unsigned long flags = 0; |
8ceee660 | 250 | |
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251 | if (page == 0) |
252 | spin_lock_irqsave(&efx->biu_lock, flags); | |
8ceee660 | 253 | falcon_writel(efx, value, FALCON_PAGED_REG(page, reg)); |
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254 | if (page == 0) |
255 | spin_unlock_irqrestore(&efx->biu_lock, flags); | |
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256 | } |
257 | ||
258 | #endif /* EFX_FALCON_IO_H */ |