1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /**************************************************************************** 3 * Driver for Solarflare network controllers and boards 4 * Copyright 2005-2006 Fen Systems Ltd. 5 * Copyright 2006-2013 Solarflare Communications Inc. 6 */ 7 8 #ifndef EFX_IO_H 9 #define EFX_IO_H 10 11 #include <linux/io.h> 12 #include <linux/spinlock.h> 13 14 /************************************************************************** 15 * 16 * NIC register I/O 17 * 18 ************************************************************************** 19 * 20 * Notes on locking strategy for the Falcon architecture: 21 * 22 * Many CSRs are very wide and cannot be read or written atomically. 23 * Writes from the host are buffered by the Bus Interface Unit (BIU) 24 * up to 128 bits. Whenever the host writes part of such a register, 25 * the BIU collects the written value and does not write to the 26 * underlying register until all 4 dwords have been written. A 27 * similar buffering scheme applies to host access to the NIC's 64-bit 28 * SRAM. 29 * 30 * Writes to different CSRs and 64-bit SRAM words must be serialised, 31 * since interleaved access can result in lost writes. We use 32 * efx_nic::biu_lock for this. 33 * 34 * We also serialise reads from 128-bit CSRs and SRAM with the same 35 * spinlock. This may not be necessary, but it doesn't really matter 36 * as there are no such reads on the fast path. 37 * 38 * The DMA descriptor pointers (RX_DESC_UPD and TX_DESC_UPD) are 39 * 128-bit but are special-cased in the BIU to avoid the need for 40 * locking in the host: 41 * 42 * - They are write-only. 43 * - The semantics of writing to these registers are such that 44 * replacing the low 96 bits with zero does not affect functionality. 45 * - If the host writes to the last dword address of such a register 46 * (i.e. the high 32 bits) the underlying register will always be 47 * written. If the collector and the current write together do not 48 * provide values for all 128 bits of the register, the low 96 bits 49 * will be written as zero. 50 * - If the host writes to the address of any other part of such a 51 * register while the collector already holds values for some other 52 * register, the write is discarded and the collector maintains its 53 * current state. 54 * 55 * The EF10 architecture exposes very few registers to the host and 56 * most of them are only 32 bits wide. The only exceptions are the MC 57 * doorbell register pair, which has its own latching, and 58 * TX_DESC_UPD, which works in a similar way to the Falcon 59 * architecture. 60 */ 61 62 #if BITS_PER_LONG == 64 63 #define EFX_USE_QWORD_IO 1 64 #endif 65 66 /* Hardware issue requires that only 64-bit naturally aligned writes 67 * are seen by hardware. Its not strictly necessary to restrict to 68 * x86_64 arch, but done for safety since unusual write combining behaviour 69 * can break PIO. 70 */ 71 #ifdef CONFIG_X86_64 72 /* PIO is a win only if write-combining is possible */ 73 #ifdef ioremap_wc 74 #define EFX_USE_PIO 1 75 #endif 76 #endif 77 78 static inline u32 efx_reg(struct efx_nic *efx, unsigned int reg) 79 { 80 return efx->reg_base + reg; 81 } 82 83 #ifdef EFX_USE_QWORD_IO 84 static inline void _efx_writeq(struct efx_nic *efx, __le64 value, 85 unsigned int reg) 86 { 87 __raw_writeq((__force u64)value, efx->membase + reg); 88 } 89 static inline __le64 _efx_readq(struct efx_nic *efx, unsigned int reg) 90 { 91 return (__force __le64)__raw_readq(efx->membase + reg); 92 } 93 #endif 94 95 static inline void _efx_writed(struct efx_nic *efx, __le32 value, 96 unsigned int reg) 97 { 98 __raw_writel((__force u32)value, efx->membase + reg); 99 } 100 static inline __le32 _efx_readd(struct efx_nic *efx, unsigned int reg) 101 { 102 return (__force __le32)__raw_readl(efx->membase + reg); 103 } 104 105 /* Write a normal 128-bit CSR, locking as appropriate. */ 106 static inline void efx_writeo(struct efx_nic *efx, const efx_oword_t *value, 107 unsigned int reg) 108 { 109 unsigned long flags __attribute__ ((unused)); 110 111 netif_vdbg(efx, hw, efx->net_dev, 112 "writing register %x with " EFX_OWORD_FMT "\n", reg, 113 EFX_OWORD_VAL(*value)); 114 115 spin_lock_irqsave(&efx->biu_lock, flags); 116 #ifdef EFX_USE_QWORD_IO 117 _efx_writeq(efx, value->u64[0], reg + 0); 118 _efx_writeq(efx, value->u64[1], reg + 8); 119 #else 120 _efx_writed(efx, value->u32[0], reg + 0); 121 _efx_writed(efx, value->u32[1], reg + 4); 122 _efx_writed(efx, value->u32[2], reg + 8); 123 _efx_writed(efx, value->u32[3], reg + 12); 124 #endif 125 spin_unlock_irqrestore(&efx->biu_lock, flags); 126 } 127 128 /* Write 64-bit SRAM through the supplied mapping, locking as appropriate. */ 129 static inline void efx_sram_writeq(struct efx_nic *efx, void __iomem *membase, 130 const efx_qword_t *value, unsigned int index) 131 { 132 unsigned int addr = index * sizeof(*value); 133 unsigned long flags __attribute__ ((unused)); 134 135 netif_vdbg(efx, hw, efx->net_dev, 136 "writing SRAM address %x with " EFX_QWORD_FMT "\n", 137 addr, EFX_QWORD_VAL(*value)); 138 139 spin_lock_irqsave(&efx->biu_lock, flags); 140 #ifdef EFX_USE_QWORD_IO 141 __raw_writeq((__force u64)value->u64[0], membase + addr); 142 #else 143 __raw_writel((__force u32)value->u32[0], membase + addr); 144 __raw_writel((__force u32)value->u32[1], membase + addr + 4); 145 #endif 146 spin_unlock_irqrestore(&efx->biu_lock, flags); 147 } 148 149 /* Write a 32-bit CSR or the last dword of a special 128-bit CSR */ 150 static inline void efx_writed(struct efx_nic *efx, const efx_dword_t *value, 151 unsigned int reg) 152 { 153 netif_vdbg(efx, hw, efx->net_dev, 154 "writing register %x with "EFX_DWORD_FMT"\n", 155 reg, EFX_DWORD_VAL(*value)); 156 157 /* No lock required */ 158 _efx_writed(efx, value->u32[0], reg); 159 } 160 161 /* Read a 128-bit CSR, locking as appropriate. */ 162 static inline void efx_reado(struct efx_nic *efx, efx_oword_t *value, 163 unsigned int reg) 164 { 165 unsigned long flags __attribute__ ((unused)); 166 167 spin_lock_irqsave(&efx->biu_lock, flags); 168 value->u32[0] = _efx_readd(efx, reg + 0); 169 value->u32[1] = _efx_readd(efx, reg + 4); 170 value->u32[2] = _efx_readd(efx, reg + 8); 171 value->u32[3] = _efx_readd(efx, reg + 12); 172 spin_unlock_irqrestore(&efx->biu_lock, flags); 173 174 netif_vdbg(efx, hw, efx->net_dev, 175 "read from register %x, got " EFX_OWORD_FMT "\n", reg, 176 EFX_OWORD_VAL(*value)); 177 } 178 179 /* Read 64-bit SRAM through the supplied mapping, locking as appropriate. */ 180 static inline void efx_sram_readq(struct efx_nic *efx, void __iomem *membase, 181 efx_qword_t *value, unsigned int index) 182 { 183 unsigned int addr = index * sizeof(*value); 184 unsigned long flags __attribute__ ((unused)); 185 186 spin_lock_irqsave(&efx->biu_lock, flags); 187 #ifdef EFX_USE_QWORD_IO 188 value->u64[0] = (__force __le64)__raw_readq(membase + addr); 189 #else 190 value->u32[0] = (__force __le32)__raw_readl(membase + addr); 191 value->u32[1] = (__force __le32)__raw_readl(membase + addr + 4); 192 #endif 193 spin_unlock_irqrestore(&efx->biu_lock, flags); 194 195 netif_vdbg(efx, hw, efx->net_dev, 196 "read from SRAM address %x, got "EFX_QWORD_FMT"\n", 197 addr, EFX_QWORD_VAL(*value)); 198 } 199 200 /* Read a 32-bit CSR or SRAM */ 201 static inline void efx_readd(struct efx_nic *efx, efx_dword_t *value, 202 unsigned int reg) 203 { 204 value->u32[0] = _efx_readd(efx, reg); 205 netif_vdbg(efx, hw, efx->net_dev, 206 "read from register %x, got "EFX_DWORD_FMT"\n", 207 reg, EFX_DWORD_VAL(*value)); 208 } 209 210 /* Write a 128-bit CSR forming part of a table */ 211 static inline void 212 efx_writeo_table(struct efx_nic *efx, const efx_oword_t *value, 213 unsigned int reg, unsigned int index) 214 { 215 efx_writeo(efx, value, reg + index * sizeof(efx_oword_t)); 216 } 217 218 /* Read a 128-bit CSR forming part of a table */ 219 static inline void efx_reado_table(struct efx_nic *efx, efx_oword_t *value, 220 unsigned int reg, unsigned int index) 221 { 222 efx_reado(efx, value, reg + index * sizeof(efx_oword_t)); 223 } 224 225 /* default VI stride (step between per-VI registers) is 8K on EF10 and 226 * 64K on EF100 227 */ 228 #define EFX_DEFAULT_VI_STRIDE 0x2000 229 #define EF100_DEFAULT_VI_STRIDE 0x10000 230 231 /* Calculate offset to page-mapped register */ 232 static inline unsigned int efx_paged_reg(struct efx_nic *efx, unsigned int page, 233 unsigned int reg) 234 { 235 return page * efx->vi_stride + reg; 236 } 237 238 /* Write the whole of RX_DESC_UPD or TX_DESC_UPD */ 239 static inline void _efx_writeo_page(struct efx_nic *efx, efx_oword_t *value, 240 unsigned int reg, unsigned int page) 241 { 242 reg = efx_paged_reg(efx, page, reg); 243 244 netif_vdbg(efx, hw, efx->net_dev, 245 "writing register %x with " EFX_OWORD_FMT "\n", reg, 246 EFX_OWORD_VAL(*value)); 247 248 #ifdef EFX_USE_QWORD_IO 249 _efx_writeq(efx, value->u64[0], reg + 0); 250 _efx_writeq(efx, value->u64[1], reg + 8); 251 #else 252 _efx_writed(efx, value->u32[0], reg + 0); 253 _efx_writed(efx, value->u32[1], reg + 4); 254 _efx_writed(efx, value->u32[2], reg + 8); 255 _efx_writed(efx, value->u32[3], reg + 12); 256 #endif 257 } 258 #define efx_writeo_page(efx, value, reg, page) \ 259 _efx_writeo_page(efx, value, \ 260 reg + \ 261 BUILD_BUG_ON_ZERO((reg) != 0x830 && (reg) != 0xa10), \ 262 page) 263 264 /* Write a page-mapped 32-bit CSR (EVQ_RPTR, EVQ_TMR (EF10), or the 265 * high bits of RX_DESC_UPD or TX_DESC_UPD) 266 */ 267 static inline void 268 _efx_writed_page(struct efx_nic *efx, const efx_dword_t *value, 269 unsigned int reg, unsigned int page) 270 { 271 efx_writed(efx, value, efx_paged_reg(efx, page, reg)); 272 } 273 #define efx_writed_page(efx, value, reg, page) \ 274 _efx_writed_page(efx, value, \ 275 reg + \ 276 BUILD_BUG_ON_ZERO((reg) != 0x180 && \ 277 (reg) != 0x200 && \ 278 (reg) != 0x400 && \ 279 (reg) != 0x420 && \ 280 (reg) != 0x830 && \ 281 (reg) != 0x83c && \ 282 (reg) != 0xa18 && \ 283 (reg) != 0xa1c), \ 284 page) 285 286 /* Write TIMER_COMMAND. This is a page-mapped 32-bit CSR, but a bug 287 * in the BIU means that writes to TIMER_COMMAND[0] invalidate the 288 * collector register. 289 */ 290 static inline void _efx_writed_page_locked(struct efx_nic *efx, 291 const efx_dword_t *value, 292 unsigned int reg, 293 unsigned int page) 294 { 295 unsigned long flags __attribute__ ((unused)); 296 297 if (page == 0) { 298 spin_lock_irqsave(&efx->biu_lock, flags); 299 efx_writed(efx, value, efx_paged_reg(efx, page, reg)); 300 spin_unlock_irqrestore(&efx->biu_lock, flags); 301 } else { 302 efx_writed(efx, value, efx_paged_reg(efx, page, reg)); 303 } 304 } 305 #define efx_writed_page_locked(efx, value, reg, page) \ 306 _efx_writed_page_locked(efx, value, \ 307 reg + BUILD_BUG_ON_ZERO((reg) != 0x420), \ 308 page) 309 310 #endif /* EFX_IO_H */ 311