diff options
Diffstat (limited to 'kernel/drivers/net/ethernet/sfc/io.h')
| -rw-r--r-- | kernel/drivers/net/ethernet/sfc/io.h | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/kernel/drivers/net/ethernet/sfc/io.h b/kernel/drivers/net/ethernet/sfc/io.h new file mode 100644 index 000000000..afb94aa2c --- /dev/null +++ b/kernel/drivers/net/ethernet/sfc/io.h @@ -0,0 +1,302 @@ +/**************************************************************************** + * 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 + +/* Hardware issue requires that only 64-bit naturally aligned writes + * are seen by hardware. Its not strictly necessary to restrict to + * x86_64 arch, but done for safety since unusual write combining behaviour + * can break PIO. + */ +#ifdef CONFIG_X86_64 +/* PIO is a win only if write-combining is possible */ +#ifdef ARCH_HAS_IOREMAP_WC +#define EFX_USE_PIO 1 +#endif +#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 */ |