Initial import

1 files changed, 302 insertions, 0 deletions

diff --git a/drivers/net/ethernet/sfc/io.h b/drivers/net/ethernet/sfc/io.h
new file mode 100644
index 000000000..afb94aa2c
--- /dev/null
+++ b/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 */