ixgbe: improve EEPROM read/write operations

Introduce buffered read/writes which greatly improves performance on
parts with large EEPROMs.

Previously reading/writing a word requires taking/releasing of synchronization
semaphores which adds 10ms to each operation. The optimization is to
read/write in buffers, but make sure the semaphore is not held for >500ms
according to the datasheet.

Since we can't read the EEPROM page size ixgbe_detect_eeprom_page_size() is
used to discover the EEPROM size when needed and keeps the result in
word_page_size for the rest of the run time.

Use buffered reads for ethtool -e.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Evan Swanson <evan.swanson@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ixgbe/ixgbe_common.h b/drivers/net/ixgbe/ixgbe_common.h
index e850adb..46be83c 100644
--- a/drivers/net/ixgbe/ixgbe_common.h
+++ b/drivers/net/ixgbe/ixgbe_common.h
@@ -49,10 +49,18 @@
 
 s32 ixgbe_init_eeprom_params_generic(struct ixgbe_hw *hw);
 s32 ixgbe_write_eeprom_generic(struct ixgbe_hw *hw, u16 offset, u16 data);
+s32 ixgbe_write_eeprom_buffer_bit_bang_generic(struct ixgbe_hw *hw, u16 offset,
+					       u16 words, u16 *data);
 s32 ixgbe_read_eerd_generic(struct ixgbe_hw *hw, u16 offset, u16 *data);
+s32 ixgbe_read_eerd_buffer_generic(struct ixgbe_hw *hw, u16 offset,
+				   u16 words, u16 *data);
 s32 ixgbe_write_eewr_generic(struct ixgbe_hw *hw, u16 offset, u16 data);
+s32 ixgbe_write_eewr_buffer_generic(struct ixgbe_hw *hw, u16 offset,
+				    u16 words, u16 *data);
 s32 ixgbe_read_eeprom_bit_bang_generic(struct ixgbe_hw *hw, u16 offset,
                                        u16 *data);
+s32 ixgbe_read_eeprom_buffer_bit_bang_generic(struct ixgbe_hw *hw, u16 offset,
+					      u16 words, u16 *data);
 u16 ixgbe_calc_eeprom_checksum_generic(struct ixgbe_hw *hw);
 s32 ixgbe_validate_eeprom_checksum_generic(struct ixgbe_hw *hw,
                                            u16 *checksum_val);