| /**************************************************************************** |
| * Driver for Solarflare Solarstorm network controllers and boards |
| * Copyright 2005-2006 Fen Systems Ltd. |
| * Copyright 2006-2009 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: |
| * |
| * Most NIC registers require 16-byte (or 8-byte, for SRAM) atomic writes |
| * which necessitates locking. |
| * Under normal operation few writes to NIC registers are made and these |
| * registers (EVQ_RPTR_REG, RX_DESC_UPD_REG and TX_DESC_UPD_REG) are special |
| * cased to allow 4-byte (hence lockless) accesses. |
| * |
| * It *is* safe to write to these 4-byte registers in the middle of an |
| * access to an 8-byte or 16-byte register. We therefore use a |
| * spinlock to protect accesses to the larger registers, but no locks |
| * for the 4-byte registers. |
| * |
| * A write barrier is needed to ensure that DW3 is written after DW0/1/2 |
| * due to the way the 16byte registers are "collected" in the BIU. |
| * |
| * We also lock when carrying out reads, to ensure consistency of the |
| * data (made possible since the BIU reads all 128 bits into a cache). |
| * Reads are very rare, so this isn't a significant performance |
| * impact. (Most data transferred from NIC to host is DMAed directly |
| * into host memory). |
| * |
| * I/O BAR access uses locks for both reads and writes (but is only provided |
| * for testing purposes). |
| */ |
| |
| #if BITS_PER_LONG == 64 |
| #define EFX_USE_QWORD_IO 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); |
| } |
| |
| /* Writes to a normal 16-byte Efx register, locking as appropriate. */ |
| static inline void efx_writeo(struct efx_nic *efx, 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); |
| wmb(); |
| _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); |
| wmb(); |
| _efx_writed(efx, value->u32[3], reg + 12); |
| #endif |
| mmiowb(); |
| spin_unlock_irqrestore(&efx->biu_lock, flags); |
| } |
| |
| /* Write an 8-byte NIC SRAM entry through the supplied mapping, |
| * locking as appropriate. */ |
| static inline void efx_sram_writeq(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)); |
| |
| 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); |
| wmb(); |
| __raw_writel((__force u32)value->u32[1], membase + addr + 4); |
| #endif |
| mmiowb(); |
| spin_unlock_irqrestore(&efx->biu_lock, flags); |
| } |
| |
| /* Write dword to NIC register that allows partial writes |
| * |
| * Some registers (EVQ_RPTR_REG, RX_DESC_UPD_REG and |
| * TX_DESC_UPD_REG) can be written to as a single dword. This allows |
| * for lockless writes. |
| */ |
| static inline void efx_writed(struct efx_nic *efx, efx_dword_t *value, |
| unsigned int reg) |
| { |
| netif_vdbg(efx, hw, efx->net_dev, |
| "writing partial register %x with "EFX_DWORD_FMT"\n", |
| reg, EFX_DWORD_VAL(*value)); |
| |
| /* No lock required */ |
| _efx_writed(efx, value->u32[0], reg); |
| } |
| |
| /* Read from a NIC register |
| * |
| * This reads an entire 16-byte register in one go, locking as |
| * appropriate. It is essential to read the first dword first, as this |
| * prompts the NIC to load the current value into the shadow register. |
| */ |
| 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); |
| rmb(); |
| 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 an 8-byte SRAM entry through 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); |
| rmb(); |
| 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 dword from register that allows partial writes (sic) */ |
| 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 to a register forming part of a table */ |
| static inline void efx_writeo_table(struct efx_nic *efx, efx_oword_t *value, |
| unsigned int reg, unsigned int index) |
| { |
| efx_writeo(efx, value, reg + index * sizeof(efx_oword_t)); |
| } |
| |
| /* Read to a register 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)); |
| } |
| |
| /* Write to a dword register forming part of a table */ |
| static inline void efx_writed_table(struct efx_nic *efx, efx_dword_t *value, |
| unsigned int reg, unsigned int index) |
| { |
| efx_writed(efx, value, reg + index * sizeof(efx_oword_t)); |
| } |
| |
| /* Read from a dword register forming part of a table */ |
| static inline void efx_readd_table(struct efx_nic *efx, efx_dword_t *value, |
| unsigned int reg, unsigned int index) |
| { |
| efx_readd(efx, value, reg + index * sizeof(efx_dword_t)); |
| } |
| |
| /* Page-mapped register block size */ |
| #define EFX_PAGE_BLOCK_SIZE 0x2000 |
| |
| /* Calculate offset to page-mapped register block */ |
| #define EFX_PAGED_REG(page, reg) \ |
| ((page) * EFX_PAGE_BLOCK_SIZE + (reg)) |
| |
| /* As for efx_writeo(), but for a page-mapped register. */ |
| static inline void efx_writeo_page(struct efx_nic *efx, efx_oword_t *value, |
| unsigned int reg, unsigned int page) |
| { |
| efx_writeo(efx, value, EFX_PAGED_REG(page, reg)); |
| } |
| |
| /* As for efx_writed(), but for a page-mapped register. */ |
| static inline void efx_writed_page(struct efx_nic *efx, efx_dword_t *value, |
| unsigned int reg, unsigned int page) |
| { |
| efx_writed(efx, value, EFX_PAGED_REG(page, reg)); |
| } |
| |
| /* Write dword to page-mapped register with an extra lock. |
| * |
| * As for efx_writed_page(), but for a register that suffers from |
| * SFC bug 3181. Take out a lock so the BIU collector cannot be |
| * confused. */ |
| static inline void efx_writed_page_locked(struct efx_nic *efx, |
| 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)); |
| } |
| } |
| |
| #endif /* EFX_IO_H */ |