falcon_io.h
/****************************************************************************
* Driver for Solarflare Solarstorm network controllers and boards
* Copyright 2005-2006 Fen Systems Ltd.
* Copyright 2006-2008 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_FALCON_IO_H
#define EFX_FALCON_IO_H
#include <linux/io.h>
#include <linux/spinlock.h>
#include "net_driver.h"
/**************************************************************************
*
* Falcon hardware access
*
**************************************************************************
*
* Notes on locking strategy:
*
* Most Falcon registers require 16-byte (or 8-byte, for SRAM
* registers) atomic writes which necessitates locking.
* Under normal operation few writes to the Falcon BAR 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 Falcon 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).
*/
/* Special buffer descriptors (Falcon SRAM) */
#define BUF_TBL_KER_A1 0x18000
#define BUF_TBL_KER_B0 0x800000
#if BITS_PER_LONG == 64
#define FALCON_USE_QWORD_IO 1
#endif
#ifdef FALCON_USE_QWORD_IO
static inline void _falcon_writeq(struct efx_nic *efx, __le64 value,
unsigned int reg)
{
__raw_writeq((__force u64)value, efx->membase + reg);
}
static inline __le64 _falcon_readq(struct efx_nic *efx, unsigned int reg)
{
return (__force __le64)__raw_readq(efx->membase + reg);
}
#endif
static inline void _falcon_writel(struct efx_nic *efx, __le32 value,
unsigned int reg)
{
__raw_writel((__force u32)value, efx->membase + reg);
}
static inline __le32 _falcon_readl(struct efx_nic *efx, unsigned int reg)
{
return (__force __le32)__raw_readl(efx->membase + reg);
}
/* Writes to a normal 16-byte Falcon register, locking as appropriate. */
static inline void falcon_write(struct efx_nic *efx, efx_oword_t *value,
unsigned int reg)
{
unsigned long flags;
EFX_REGDUMP(efx, "writing register %x with " EFX_OWORD_FMT "\n", reg,
EFX_OWORD_VAL(*value));
spin_lock_irqsave(&efx->biu_lock, flags);
#ifdef FALCON_USE_QWORD_IO
_falcon_writeq(efx, value->u64[0], reg + 0);
wmb();
_falcon_writeq(efx, value->u64[1], reg + 8);
#else
_falcon_writel(efx, value->u32[0], reg + 0);
_falcon_writel(efx, value->u32[1], reg + 4);
_falcon_writel(efx, value->u32[2], reg + 8);
wmb();
_falcon_writel(efx, value->u32[3], reg + 12);
#endif
mmiowb();
spin_unlock_irqrestore(&efx->biu_lock, flags);
}
/* Writes to an 8-byte Falcon SRAM register, locking as appropriate. */
static inline void falcon_write_sram(struct efx_nic *efx, efx_qword_t *value,
unsigned int index)
{
unsigned int reg = efx->type->buf_tbl_base + (index * sizeof(*value));
unsigned long flags;
EFX_REGDUMP(efx, "writing SRAM register %x with " EFX_QWORD_FMT "\n",
reg, EFX_QWORD_VAL(*value));
spin_lock_irqsave(&efx->biu_lock, flags);
#ifdef FALCON_USE_QWORD_IO
_falcon_writeq(efx, value->u64[0], reg + 0);
#else
_falcon_writel(efx, value->u32[0], reg + 0);
wmb();
_falcon_writel(efx, value->u32[1], reg + 4);
#endif
mmiowb();
spin_unlock_irqrestore(&efx->biu_lock, flags);
}
/* Write dword to Falcon register that allows partial writes
*
* Some Falcon 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 falcon_writel(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 */
_falcon_writel(efx, value->u32[0], reg);
}
/* Read from a Falcon register
*
* This reads an entire 16-byte Falcon register in one go, locking as
* appropriate. It is essential to read the first dword first, as this
* prompts Falcon to load the current value into the shadow register.
*/
static inline void falcon_read(struct efx_nic *efx, efx_oword_t *value,
unsigned int reg)
{
unsigned long flags;
spin_lock_irqsave(&efx->biu_lock, flags);
value->u32[0] = _falcon_readl(efx, reg + 0);
rmb();
value->u32[1] = _falcon_readl(efx, reg + 4);
value->u32[2] = _falcon_readl(efx, reg + 8);
value->u32[3] = _falcon_readl(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));
}
/* This reads an 8-byte Falcon SRAM entry in one go. */
static inline void falcon_read_sram(struct efx_nic *efx, efx_qword_t *value,
unsigned int index)
{
unsigned int reg = efx->type->buf_tbl_base + (index * sizeof(*value));
unsigned long flags;
spin_lock_irqsave(&efx->biu_lock, flags);
#ifdef FALCON_USE_QWORD_IO
value->u64[0] = _falcon_readq(efx, reg + 0);
#else
value->u32[0] = _falcon_readl(efx, reg + 0);
rmb();
value->u32[1] = _falcon_readl(efx, reg + 4);
#endif
spin_unlock_irqrestore(&efx->biu_lock, flags);
EFX_REGDUMP(efx, "read from SRAM register %x, got "EFX_QWORD_FMT"\n",
reg, EFX_QWORD_VAL(*value));
}
/* Read dword from Falcon register that allows partial writes (sic) */
static inline void falcon_readl(struct efx_nic *efx, efx_dword_t *value,
unsigned int reg)
{
value->u32[0] = _falcon_readl(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 falcon_write_table(struct efx_nic *efx, efx_oword_t *value,
unsigned int reg, unsigned int index)
{
falcon_write(efx, value, reg + index * sizeof(efx_oword_t));
}
/* Read to a register forming part of a table */
static inline void falcon_read_table(struct efx_nic *efx, efx_oword_t *value,
unsigned int reg, unsigned int index)
{
falcon_read(efx, value, reg + index * sizeof(efx_oword_t));
}
/* Write to a dword register forming part of a table */
static inline void falcon_writel_table(struct efx_nic *efx, efx_dword_t *value,
unsigned int reg, unsigned int index)
{
falcon_writel(efx, value, reg + index * sizeof(efx_oword_t));
}
/* Page-mapped register block size */
#define FALCON_PAGE_BLOCK_SIZE 0x2000
/* Calculate offset to page-mapped register block */
#define FALCON_PAGED_REG(page, reg) \
((page) * FALCON_PAGE_BLOCK_SIZE + (reg))
/* As for falcon_write(), but for a page-mapped register. */
static inline void falcon_write_page(struct efx_nic *efx, efx_oword_t *value,
unsigned int reg, unsigned int page)
{
falcon_write(efx, value, FALCON_PAGED_REG(page, reg));
}
/* As for falcon_writel(), but for a page-mapped register. */
static inline void falcon_writel_page(struct efx_nic *efx, efx_dword_t *value,
unsigned int reg, unsigned int page)
{
falcon_writel(efx, value, FALCON_PAGED_REG(page, reg));
}
/* Write dword to Falcon page-mapped register with an extra lock.
*
* As for falcon_writel_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 falcon_writel_page_locked(struct efx_nic *efx,
efx_dword_t *value,
unsigned int reg,
unsigned int page)
{
unsigned long flags;
spin_lock_irqsave(&efx->biu_lock, flags);
falcon_writel(efx, value, FALCON_PAGED_REG(page, reg));
spin_unlock_irqrestore(&efx->biu_lock, flags);
}
#endif /* EFX_FALCON_IO_H */
