ixgbe: cache AUTOC reads

This patch removes majority of the AUTOC register reads by using a cached
value instead.

The reason for this change is to avoid writing corrupted values to AUTOC
due to bad FW.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

2 files changed, 25 insertions, 16 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_82599.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_82599.c
index 3f792428ca53..c4c5e878b8a9 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_82599.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_82599.c
@@ -167,9 +167,9 @@ static s32 ixgbe_setup_sfp_modules_82599(struct ixgbe_hw *hw)
                 }
 
                 /* Restart DSP and set SFI mode */
-                IXGBE_WRITE_REG(hw, IXGBE_AUTOC, (IXGBE_READ_REG(hw,
-                                IXGBE_AUTOC) | IXGBE_AUTOC_LMS_10G_SERIAL));
-
+                IXGBE_WRITE_REG(hw, IXGBE_AUTOC, ((hw->mac.orig_autoc) |
+                                IXGBE_AUTOC_LMS_10G_SERIAL));
+                hw->mac.cached_autoc = IXGBE_READ_REG(hw, IXGBE_AUTOC);
                 ret_val = ixgbe_reset_pipeline_82599(hw);
 
                 if (got_lock) {
@@ -803,12 +803,9 @@ static s32 ixgbe_setup_mac_link_82599(struct ixgbe_hw *hw,
                                       bool autoneg_wait_to_complete)
 {
         s32 status = 0;
-        u32 autoc = IXGBE_READ_REG(hw, IXGBE_AUTOC);
+        u32 autoc, pma_pmd_1g, link_mode, start_autoc;
         u32 autoc2 = IXGBE_READ_REG(hw, IXGBE_AUTOC2);
-        u32 start_autoc = autoc;
         u32 orig_autoc = 0;
-        u32 link_mode = autoc & IXGBE_AUTOC_LMS_MASK;
-        u32 pma_pmd_1g = autoc & IXGBE_AUTOC_1G_PMA_PMD_MASK;
         u32 pma_pmd_10g_serial = autoc2 & IXGBE_AUTOC2_10G_SERIAL_PMA_PMD_MASK;
         u32 links_reg;
         u32 i;
@@ -831,9 +828,14 @@ static s32 ixgbe_setup_mac_link_82599(struct ixgbe_hw *hw,
 
         /* Use stored value (EEPROM defaults) of AUTOC to find KR/KX4 support*/
         if (hw->mac.orig_link_settings_stored)
-                orig_autoc = hw->mac.orig_autoc;
+                autoc = hw->mac.orig_autoc;
         else
-                orig_autoc = autoc;
+                autoc = IXGBE_READ_REG(hw, IXGBE_AUTOC);
+
+        orig_autoc = autoc;
+        start_autoc = hw->mac.cached_autoc;
+        link_mode = autoc & IXGBE_AUTOC_LMS_MASK;
+        pma_pmd_1g = autoc & IXGBE_AUTOC_1G_PMA_PMD_MASK;
 
         if (link_mode == IXGBE_AUTOC_LMS_KX4_KX_KR ||
             link_mode == IXGBE_AUTOC_LMS_KX4_KX_KR_1G_AN ||
@@ -887,6 +889,7 @@ static s32 ixgbe_setup_mac_link_82599(struct ixgbe_hw *hw,
 
                 /* Restart link */
                 IXGBE_WRITE_REG(hw, IXGBE_AUTOC, autoc);
+                hw->mac.cached_autoc = autoc;
                 ixgbe_reset_pipeline_82599(hw);
 
                 if (got_lock)
@@ -958,7 +961,7 @@ static s32 ixgbe_reset_hw_82599(struct ixgbe_hw *hw)
 {
         ixgbe_link_speed link_speed;
         s32 status;
-        u32 ctrl, i, autoc, autoc2;
+        u32 ctrl, i, autoc2;
         u32 curr_lms;
         bool link_up = false;
 
@@ -991,8 +994,12 @@ static s32 ixgbe_reset_hw_82599(struct ixgbe_hw *hw)
         if (hw->phy.reset_disable == false && hw->phy.ops.reset != NULL)
                 hw->phy.ops.reset(hw);
 
-        /* remember AUTOC LMS from before we reset */
-        curr_lms = IXGBE_READ_REG(hw, IXGBE_AUTOC) & IXGBE_AUTOC_LMS_MASK;
+        /* remember AUTOC from before we reset */
+        if (hw->mac.cached_autoc)
+                curr_lms = hw->mac.cached_autoc & IXGBE_AUTOC_LMS_MASK;
+        else
+                curr_lms = IXGBE_READ_REG(hw, IXGBE_AUTOC) &
+                           IXGBE_AUTOC_LMS_MASK;
 
 mac_reset_top:
         /*
@@ -1042,10 +1049,10 @@ mac_reset_top:
          * stored off yet.  Otherwise restore the stored original
          * values since the reset operation sets back to defaults.
          */
-        autoc = IXGBE_READ_REG(hw, IXGBE_AUTOC);
+        hw->mac.cached_autoc = IXGBE_READ_REG(hw, IXGBE_AUTOC);
         autoc2 = IXGBE_READ_REG(hw, IXGBE_AUTOC2);
         if (hw->mac.orig_link_settings_stored == false) {
-                hw->mac.orig_autoc = autoc;
+                hw->mac.orig_autoc = hw->mac.cached_autoc;
                 hw->mac.orig_autoc2 = autoc2;
                 hw->mac.orig_link_settings_stored = true;
         } else {
@@ -1062,7 +1069,7 @@ mac_reset_top:
                                 (hw->mac.orig_autoc & ~IXGBE_AUTOC_LMS_MASK) |
                                 curr_lms;
 
-                if (autoc != hw->mac.orig_autoc) {
+                if (hw->mac.cached_autoc != hw->mac.orig_autoc) {
                         /* Need SW/FW semaphore around AUTOC writes if LESM is
                          * on, likewise reset_pipeline requires us to hold
                          * this lock as it also writes to AUTOC.
@@ -1078,6 +1085,7 @@ mac_reset_top:
                         }
 
                         IXGBE_WRITE_REG(hw, IXGBE_AUTOC, hw->mac.orig_autoc);
+                        hw->mac.cached_autoc = hw->mac.orig_autoc;
                         ixgbe_reset_pipeline_82599(hw);
 
                         if (got_lock)
@@ -2181,7 +2189,7 @@ s32 ixgbe_reset_pipeline_82599(struct ixgbe_hw *hw)
         s32 i, autoc_reg, ret_val;
         s32 anlp1_reg = 0;
 
-        autoc_reg = IXGBE_READ_REG(hw, IXGBE_AUTOC);
+        autoc_reg = hw->mac.cached_autoc;
         autoc_reg |= IXGBE_AUTOC_AN_RESTART;
 
         /* Write AUTOC register with toggled LMS[2] bit and Restart_AN */
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
index 6d7066531139..7480f7b4ac75 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
@@ -2928,6 +2928,7 @@ struct ixgbe_mac_info {
         u32                             max_tx_queues;
         u32                             max_rx_queues;
         u32                             orig_autoc;
+        u32                             cached_autoc;
         u32                             orig_autoc2;
         bool                            orig_link_settings_stored;
         bool                            autotry_restart;