1 /**************************************************************************** 2 * Driver for Solarflare network controllers and boards 3 * Copyright 2005-2006 Fen Systems Ltd. 4 * Copyright 2006-2013 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_IO_H 12 #define EFX_IO_H 13 14 #include <linux/io.h> 15 #include <linux/spinlock.h> 16 17 /************************************************************************** 18 * 19 * NIC register I/O 20 * 21 ************************************************************************** 22 * 23 * Notes on locking strategy for the Falcon architecture: 24 * 25 * Many CSRs are very wide and cannot be read or written atomically. 26 * Writes from the host are buffered by the Bus Interface Unit (BIU) 27 * up to 128 bits. Whenever the host writes part of such a register, 28 * the BIU collects the written value and does not write to the 29 * underlying register until all 4 dwords have been written. A 30 * similar buffering scheme applies to host access to the NIC's 64-bit 31 * SRAM. 32 * 33 * Writes to different CSRs and 64-bit SRAM words must be serialised, 34 * since interleaved access can result in lost writes. We use 35 * efx_nic::biu_lock for this. 36 * 37 * We also serialise reads from 128-bit CSRs and SRAM with the same 38 * spinlock. This may not be necessary, but it doesn't really matter 39 * as there are no such reads on the fast path. 40 * 41 * The DMA descriptor pointers (RX_DESC_UPD and TX_DESC_UPD) are 42 * 128-bit but are special-cased in the BIU to avoid the need for 43 * locking in the host: 44 * 45 * - They are write-only. 46 * - The semantics of writing to these registers are such that 47 * replacing the low 96 bits with zero does not affect functionality. 48 * - If the host writes to the last dword address of such a register 49 * (i.e. the high 32 bits) the underlying register will always be 50 * written. If the collector and the current write together do not 51 * provide values for all 128 bits of the register, the low 96 bits 52 * will be written as zero. 53 * - If the host writes to the address of any other part of such a 54 * register while the collector already holds values for some other 55 * register, the write is discarded and the collector maintains its 56 * current state. 57 * 58 * The EF10 architecture exposes very few registers to the host and 59 * most of them are only 32 bits wide. The only exceptions are the MC 60 * doorbell register pair, which has its own latching, and 61 * TX_DESC_UPD, which works in a similar way to the Falcon 62 * architecture. 63 */ 64 65 #if BITS_PER_LONG == 64 66 #define EFX_USE_QWORD_IO 1 67 #endif 68 69 /* Hardware issue requires that only 64-bit naturally aligned writes 70 * are seen by hardware. Its not strictly necessary to restrict to 71 * x86_64 arch, but done for safety since unusual write combining behaviour 72 * can break PIO. 73 */ 74 #ifdef CONFIG_X86_64 75 /* PIO is a win only if write-combining is possible */ 76 #ifdef ARCH_HAS_IOREMAP_WC 77 #define EFX_USE_PIO 1 78 #endif 79 #endif 80 81 #ifdef EFX_USE_QWORD_IO 82 static inline void _efx_writeq(struct efx_nic *efx, __le64 value, 83 unsigned int reg) 84 { 85 __raw_writeq((__force u64)value, efx->membase + reg); 86 } 87 static inline __le64 _efx_readq(struct efx_nic *efx, unsigned int reg) 88 { 89 return (__force __le64)__raw_readq(efx->membase + reg); 90 } 91 #endif 92 93 static inline void _efx_writed(struct efx_nic *efx, __le32 value, 94 unsigned int reg) 95 { 96 __raw_writel((__force u32)value, efx->membase + reg); 97 } 98 static inline __le32 _efx_readd(struct efx_nic *efx, unsigned int reg) 99 { 100 return (__force __le32)__raw_readl(efx->membase + reg); 101 } 102 103 /* Write a normal 128-bit CSR, locking as appropriate. */ 104 static inline void efx_writeo(struct efx_nic *efx, const efx_oword_t *value, 105 unsigned int reg) 106 { 107 unsigned long flags __attribute__ ((unused)); 108 109 netif_vdbg(efx, hw, efx->net_dev, 110 "writing register %x with " EFX_OWORD_FMT "\n", reg, 111 EFX_OWORD_VAL(*value)); 112 113 spin_lock_irqsave(&efx->biu_lock, flags); 114 #ifdef EFX_USE_QWORD_IO 115 _efx_writeq(efx, value->u64[0], reg + 0); 116 _efx_writeq(efx, value->u64[1], reg + 8); 117 #else 118 _efx_writed(efx, value->u32[0], reg + 0); 119 _efx_writed(efx, value->u32[1], reg + 4); 120 _efx_writed(efx, value->u32[2], reg + 8); 121 _efx_writed(efx, value->u32[3], reg + 12); 122 #endif 123 spin_unlock_irqrestore(&efx->biu_lock, flags); 124 } 125 126 /* Write 64-bit SRAM through the supplied mapping, locking as appropriate. */ 127 static inline void efx_sram_writeq(struct efx_nic *efx, void __iomem *membase, 128 const efx_qword_t *value, unsigned int index) 129 { 130 unsigned int addr = index * sizeof(*value); 131 unsigned long flags __attribute__ ((unused)); 132 133 netif_vdbg(efx, hw, efx->net_dev, 134 "writing SRAM address %x with " EFX_QWORD_FMT "\n", 135 addr, EFX_QWORD_VAL(*value)); 136 137 spin_lock_irqsave(&efx->biu_lock, flags); 138 #ifdef EFX_USE_QWORD_IO 139 __raw_writeq((__force u64)value->u64[0], membase + addr); 140 #else 141 __raw_writel((__force u32)value->u32[0], membase + addr); 142 __raw_writel((__force u32)value->u32[1], membase + addr + 4); 143 #endif 144 spin_unlock_irqrestore(&efx->biu_lock, flags); 145 } 146 147 /* Write a 32-bit CSR or the last dword of a special 128-bit CSR */ 148 static inline void efx_writed(struct efx_nic *efx, const efx_dword_t *value, 149 unsigned int reg) 150 { 151 netif_vdbg(efx, hw, efx->net_dev, 152 "writing register %x with "EFX_DWORD_FMT"\n", 153 reg, EFX_DWORD_VAL(*value)); 154 155 /* No lock required */ 156 _efx_writed(efx, value->u32[0], reg); 157 } 158 159 /* Read a 128-bit CSR, locking as appropriate. */ 160 static inline void efx_reado(struct efx_nic *efx, efx_oword_t *value, 161 unsigned int reg) 162 { 163 unsigned long flags __attribute__ ((unused)); 164 165 spin_lock_irqsave(&efx->biu_lock, flags); 166 value->u32[0] = _efx_readd(efx, reg + 0); 167 value->u32[1] = _efx_readd(efx, reg + 4); 168 value->u32[2] = _efx_readd(efx, reg + 8); 169 value->u32[3] = _efx_readd(efx, reg + 12); 170 spin_unlock_irqrestore(&efx->biu_lock, flags); 171 172 netif_vdbg(efx, hw, efx->net_dev, 173 "read from register %x, got " EFX_OWORD_FMT "\n", reg, 174 EFX_OWORD_VAL(*value)); 175 } 176 177 /* Read 64-bit SRAM through the supplied mapping, locking as appropriate. */ 178 static inline void efx_sram_readq(struct efx_nic *efx, void __iomem *membase, 179 efx_qword_t *value, unsigned int index) 180 { 181 unsigned int addr = index * sizeof(*value); 182 unsigned long flags __attribute__ ((unused)); 183 184 spin_lock_irqsave(&efx->biu_lock, flags); 185 #ifdef EFX_USE_QWORD_IO 186 value->u64[0] = (__force __le64)__raw_readq(membase + addr); 187 #else 188 value->u32[0] = (__force __le32)__raw_readl(membase + addr); 189 value->u32[1] = (__force __le32)__raw_readl(membase + addr + 4); 190 #endif 191 spin_unlock_irqrestore(&efx->biu_lock, flags); 192 193 netif_vdbg(efx, hw, efx->net_dev, 194 "read from SRAM address %x, got "EFX_QWORD_FMT"\n", 195 addr, EFX_QWORD_VAL(*value)); 196 } 197 198 /* Read a 32-bit CSR or SRAM */ 199 static inline void efx_readd(struct efx_nic *efx, efx_dword_t *value, 200 unsigned int reg) 201 { 202 value->u32[0] = _efx_readd(efx, reg); 203 netif_vdbg(efx, hw, efx->net_dev, 204 "read from register %x, got "EFX_DWORD_FMT"\n", 205 reg, EFX_DWORD_VAL(*value)); 206 } 207 208 /* Write a 128-bit CSR forming part of a table */ 209 static inline void 210 efx_writeo_table(struct efx_nic *efx, const efx_oword_t *value, 211 unsigned int reg, unsigned int index) 212 { 213 efx_writeo(efx, value, reg + index * sizeof(efx_oword_t)); 214 } 215 216 /* Read a 128-bit CSR forming part of a table */ 217 static inline void efx_reado_table(struct efx_nic *efx, efx_oword_t *value, 218 unsigned int reg, unsigned int index) 219 { 220 efx_reado(efx, value, reg + index * sizeof(efx_oword_t)); 221 } 222 223 /* default VI stride (step between per-VI registers) is 8K */ 224 #define EFX_DEFAULT_VI_STRIDE 0x2000 225 226 /* Calculate offset to page-mapped register */ 227 static inline unsigned int efx_paged_reg(struct efx_nic *efx, unsigned int page, 228 unsigned int reg) 229 { 230 return page * efx->vi_stride + reg; 231 } 232 233 /* Write the whole of RX_DESC_UPD or TX_DESC_UPD */ 234 static inline void _efx_writeo_page(struct efx_nic *efx, efx_oword_t *value, 235 unsigned int reg, unsigned int page) 236 { 237 reg = efx_paged_reg(efx, page, reg); 238 239 netif_vdbg(efx, hw, efx->net_dev, 240 "writing register %x with " EFX_OWORD_FMT "\n", reg, 241 EFX_OWORD_VAL(*value)); 242 243 #ifdef EFX_USE_QWORD_IO 244 _efx_writeq(efx, value->u64[0], reg + 0); 245 _efx_writeq(efx, value->u64[1], reg + 8); 246 #else 247 _efx_writed(efx, value->u32[0], reg + 0); 248 _efx_writed(efx, value->u32[1], reg + 4); 249 _efx_writed(efx, value->u32[2], reg + 8); 250 _efx_writed(efx, value->u32[3], reg + 12); 251 #endif 252 } 253 #define efx_writeo_page(efx, value, reg, page) \ 254 _efx_writeo_page(efx, value, \ 255 reg + \ 256 BUILD_BUG_ON_ZERO((reg) != 0x830 && (reg) != 0xa10), \ 257 page) 258 259 /* Write a page-mapped 32-bit CSR (EVQ_RPTR, EVQ_TMR (EF10), or the 260 * high bits of RX_DESC_UPD or TX_DESC_UPD) 261 */ 262 static inline void 263 _efx_writed_page(struct efx_nic *efx, const efx_dword_t *value, 264 unsigned int reg, unsigned int page) 265 { 266 efx_writed(efx, value, efx_paged_reg(efx, page, reg)); 267 } 268 #define efx_writed_page(efx, value, reg, page) \ 269 _efx_writed_page(efx, value, \ 270 reg + \ 271 BUILD_BUG_ON_ZERO((reg) != 0x400 && \ 272 (reg) != 0x420 && \ 273 (reg) != 0x830 && \ 274 (reg) != 0x83c && \ 275 (reg) != 0xa18 && \ 276 (reg) != 0xa1c), \ 277 page) 278 279 /* Write TIMER_COMMAND. This is a page-mapped 32-bit CSR, but a bug 280 * in the BIU means that writes to TIMER_COMMAND[0] invalidate the 281 * collector register. 282 */ 283 static inline void _efx_writed_page_locked(struct efx_nic *efx, 284 const efx_dword_t *value, 285 unsigned int reg, 286 unsigned int page) 287 { 288 unsigned long flags __attribute__ ((unused)); 289 290 if (page == 0) { 291 spin_lock_irqsave(&efx->biu_lock, flags); 292 efx_writed(efx, value, efx_paged_reg(efx, page, reg)); 293 spin_unlock_irqrestore(&efx->biu_lock, flags); 294 } else { 295 efx_writed(efx, value, efx_paged_reg(efx, page, reg)); 296 } 297 } 298 #define efx_writed_page_locked(efx, value, reg, page) \ 299 _efx_writed_page_locked(efx, value, \ 300 reg + BUILD_BUG_ON_ZERO((reg) != 0x420), \ 301 page) 302 303 #endif /* EFX_IO_H */ 304