--- zzzz-none-000/linux-3.10.107/drivers/net/ethernet/sfc/io.h	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/net/ethernet/sfc/io.h	2021-02-04 17:41:59.000000000 +0000
@@ -1,7 +1,7 @@
 /****************************************************************************
- * Driver for Solarflare Solarstorm network controllers and boards
+ * Driver for Solarflare network controllers and boards
  * Copyright 2005-2006 Fen Systems Ltd.
- * Copyright 2006-2010 Solarflare Communications Inc.
+ * 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
@@ -20,7 +20,7 @@
  *
  **************************************************************************
  *
- * Notes on locking strategy:
+ * 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)
@@ -54,12 +54,30 @@
  *   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)
@@ -83,7 +101,7 @@
 }
 
 /* Write a normal 128-bit CSR, locking as appropriate. */
-static inline void efx_writeo(struct efx_nic *efx, efx_oword_t *value,
+static inline void efx_writeo(struct efx_nic *efx, const efx_oword_t *value,
 			      unsigned int reg)
 {
 	unsigned long flags __attribute__ ((unused));
@@ -108,7 +126,7 @@
 
 /* Write 64-bit SRAM 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)
+				   const efx_qword_t *value, unsigned int index)
 {
 	unsigned int addr = index * sizeof(*value);
 	unsigned long flags __attribute__ ((unused));
@@ -129,7 +147,7 @@
 }
 
 /* Write a 32-bit CSR or the last dword of a special 128-bit CSR */
-static inline void efx_writed(struct efx_nic *efx, efx_dword_t *value,
+static inline void efx_writed(struct efx_nic *efx, const efx_dword_t *value,
 			      unsigned int reg)
 {
 	netif_vdbg(efx, hw, efx->net_dev,
@@ -190,8 +208,9 @@
 }
 
 /* Write a 128-bit CSR 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)
+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));
 }
@@ -203,12 +222,12 @@
 	efx_reado(efx, value, reg + index * sizeof(efx_oword_t));
 }
 
-/* Page-mapped register block size */
-#define EFX_PAGE_BLOCK_SIZE 0x2000
+/* Page size used as step between per-VI registers */
+#define EFX_VI_PAGE_SIZE 0x2000
 
-/* Calculate offset to page-mapped register block */
+/* Calculate offset to page-mapped register */
 #define EFX_PAGED_REG(page, reg) \
-	((page) * EFX_PAGE_BLOCK_SIZE + (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,
@@ -236,19 +255,24 @@
 			 BUILD_BUG_ON_ZERO((reg) != 0x830 && (reg) != 0xa10), \
 			 page)
 
-/* Write a page-mapped 32-bit CSR (EVQ_RPTR or the high bits of
- * RX_DESC_UPD or TX_DESC_UPD)
+/* 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, efx_dword_t *value,
-				    unsigned int reg, unsigned int page)
+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) != 0x83c \
-					   && (reg) != 0xa1c),		\
+			 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
@@ -256,7 +280,7 @@
  * collector register.
  */
 static inline void _efx_writed_page_locked(struct efx_nic *efx,
-					   efx_dword_t *value,
+					   const efx_dword_t *value,
 					   unsigned int reg,
 					   unsigned int page)
 {