/****************************************************************************
* 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));
EFX_REGDUMP(efx, "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));
EFX_REGDUMP(efx, "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)
{
EFX_REGDUMP(efx, "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);
EFX_REGDUMP(efx, "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);
EFX_REGDUMP(efx, "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);
EFX_REGDUMP(efx, "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));
}
/* 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 */
