drivers/net/sfc/io.h - kernel/skids - Git at Google

 /****************************************************************************
  * 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 */
	/****************************************************************************
	* 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 */