ixgbe: cleanup checksum to allow error results

Currently the shared code checksum calculation function only
returns a u16 and cannot return an error code. Unfortunately
a variety of errors can happen that completely prevent the
calculation of a checksum. So, change the function return value
from a u16 to an s32 and return a negative value on error, or the
positive checksum value when there is no error.

Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

4 files changed, 96 insertions, 53 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
index 2c77539b20db..7633ba1d4e27 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
@@ -1625,7 +1625,7 @@ static void ixgbe_release_eeprom(struct ixgbe_hw *hw)
  *  ixgbe_calc_eeprom_checksum_generic - Calculates and returns the checksum
  *  @hw: pointer to hardware structure
  **/
-u16 ixgbe_calc_eeprom_checksum_generic(struct ixgbe_hw *hw)
+s32 ixgbe_calc_eeprom_checksum_generic(struct ixgbe_hw *hw)
 {
         u16 i;
         u16 j;
@@ -1636,7 +1636,7 @@ u16 ixgbe_calc_eeprom_checksum_generic(struct ixgbe_hw *hw)
 
         /* Include 0x0-0x3F in the checksum */
         for (i = 0; i < IXGBE_EEPROM_CHECKSUM; i++) {
-                if (hw->eeprom.ops.read(hw, i, &word) != 0) {
+                if (hw->eeprom.ops.read(hw, i, &word)) {
                         hw_dbg(hw, "EEPROM read failed\n");
                         break;
                 }
@@ -1645,24 +1645,35 @@ u16 ixgbe_calc_eeprom_checksum_generic(struct ixgbe_hw *hw)
 
         /* Include all data from pointers except for the fw pointer */
         for (i = IXGBE_PCIE_ANALOG_PTR; i < IXGBE_FW_PTR; i++) {
-                hw->eeprom.ops.read(hw, i, &pointer);
+                if (hw->eeprom.ops.read(hw, i, &pointer)) {
+                        hw_dbg(hw, "EEPROM read failed\n");
+                        return IXGBE_ERR_EEPROM;
+                }
+
+                /* If the pointer seems invalid */
+                if (pointer == 0xFFFF || pointer == 0)
+                        continue;
+
+                if (hw->eeprom.ops.read(hw, pointer, &length)) {
+                        hw_dbg(hw, "EEPROM read failed\n");
+                        return IXGBE_ERR_EEPROM;
+                }
 
-                /* Make sure the pointer seems valid */
-                if (pointer != 0xFFFF && pointer != 0) {
-                        hw->eeprom.ops.read(hw, pointer, &length);
+                if (length == 0xFFFF || length == 0)
+                        continue;
 
-                        if (length != 0xFFFF && length != 0) {
-                                for (j = pointer+1; j <= pointer+length; j++) {
-                                        hw->eeprom.ops.read(hw, j, &word);
-                                        checksum += word;
-                                }
+                for (j = pointer + 1; j <= pointer + length; j++) {
+                        if (hw->eeprom.ops.read(hw, j, &word)) {
+                                hw_dbg(hw, "EEPROM read failed\n");
+                                return IXGBE_ERR_EEPROM;
                         }
+                        checksum += word;
                 }
         }
 
         checksum = (u16)IXGBE_EEPROM_SUM - checksum;
 
-        return checksum;
+        return (s32)checksum;
 }
 
 /**
@@ -1686,26 +1697,33 @@ s32 ixgbe_validate_eeprom_checksum_generic(struct ixgbe_hw *hw,
          * EEPROM read fails
          */
         status = hw->eeprom.ops.read(hw, 0, &checksum);
+        if (status) {
+                hw_dbg(hw, "EEPROM read failed\n");
+                return status;
+        }
 
-        if (status == 0) {
-                checksum = hw->eeprom.ops.calc_checksum(hw);
+        status = hw->eeprom.ops.calc_checksum(hw);
+        if (status < 0)
+                return status;
 
-                hw->eeprom.ops.read(hw, IXGBE_EEPROM_CHECKSUM, &read_checksum);
+        checksum = (u16)(status & 0xffff);
 
-                /*
-                 * Verify read checksum from EEPROM is the same as
-                 * calculated checksum
-                 */
-                if (read_checksum != checksum)
-                        status = IXGBE_ERR_EEPROM_CHECKSUM;
-
-                /* If the user cares, return the calculated checksum */
-                if (checksum_val)
-                        *checksum_val = checksum;
-        } else {
+        status = hw->eeprom.ops.read(hw, IXGBE_EEPROM_CHECKSUM, &read_checksum);
+        if (status) {
                 hw_dbg(hw, "EEPROM read failed\n");
+                return status;
         }
 
+        /* Verify read checksum from EEPROM is the same as
+         * calculated checksum
+         */
+        if (read_checksum != checksum)
+                status = IXGBE_ERR_EEPROM_CHECKSUM;
+
+        /* If the user cares, return the calculated checksum */
+        if (checksum_val)
+                *checksum_val = checksum;
+
         return status;
 }
 
@@ -1724,15 +1742,19 @@ s32 ixgbe_update_eeprom_checksum_generic(struct ixgbe_hw *hw)
          * EEPROM read fails
          */
         status = hw->eeprom.ops.read(hw, 0, &checksum);
-
-        if (status == 0) {
-                checksum = hw->eeprom.ops.calc_checksum(hw);
-                status = hw->eeprom.ops.write(hw, IXGBE_EEPROM_CHECKSUM,
-                                              checksum);
-        } else {
+        if (status) {
                 hw_dbg(hw, "EEPROM read failed\n");
+                return status;
         }
 
+        status = hw->eeprom.ops.calc_checksum(hw);
+        if (status < 0)
+                return status;
+
+        checksum = (u16)(status & 0xffff);
+
+        status = hw->eeprom.ops.write(hw, IXGBE_EEPROM_CHECKSUM, checksum);
+
         return status;
 }
 
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.h
index 62dc8c5ae3db..fdf42c1be20d 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.h
@@ -64,7 +64,7 @@ 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_calc_eeprom_checksum_generic(struct ixgbe_hw *hw);
 s32 ixgbe_validate_eeprom_checksum_generic(struct ixgbe_hw *hw,
                                            u16 *checksum_val);
 s32 ixgbe_update_eeprom_checksum_generic(struct ixgbe_hw *hw);
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
index 14b43b9f49db..20673b314f4a 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
@@ -2871,7 +2871,7 @@ struct ixgbe_eeprom_operations {
         s32 (*write_buffer)(struct ixgbe_hw *, u16, u16, u16 *);
         s32 (*validate_checksum)(struct ixgbe_hw *, u16 *);
         s32 (*update_checksum)(struct ixgbe_hw *);
-        u16 (*calc_checksum)(struct ixgbe_hw *);
+        s32 (*calc_checksum)(struct ixgbe_hw *);
 };
 
 struct ixgbe_mac_operations {
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_x540.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_x540.c
index d88f75fbd832..4b0b1cc77eb4 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_x540.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_x540.c
@@ -316,7 +316,7 @@ static s32 ixgbe_write_eewr_buffer_X540(struct ixgbe_hw *hw,
  *
  *  @hw: pointer to hardware structure
  **/
-static u16 ixgbe_calc_eeprom_checksum_X540(struct ixgbe_hw *hw)
+static s32 ixgbe_calc_eeprom_checksum_X540(struct ixgbe_hw *hw)
 {
         u16 i;
         u16 j;
@@ -324,6 +324,8 @@ static u16 ixgbe_calc_eeprom_checksum_X540(struct ixgbe_hw *hw)
         u16 length = 0;
         u16 pointer = 0;
         u16 word = 0;
+        u16 checksum_last_word = IXGBE_EEPROM_CHECKSUM;
+        u16 ptr_start = IXGBE_PCIE_ANALOG_PTR;
 
         /*
          * Do not use hw->eeprom.ops.read because we do not want to take
@@ -332,10 +334,10 @@ static u16 ixgbe_calc_eeprom_checksum_X540(struct ixgbe_hw *hw)
          */
 
         /* Include 0x0-0x3F in the checksum */
-        for (i = 0; i < IXGBE_EEPROM_CHECKSUM; i++) {
-                if (ixgbe_read_eerd_generic(hw, i, &word) != 0) {
+        for (i = 0; i < checksum_last_word; i++) {
+                if (ixgbe_read_eerd_generic(hw, i, &word)) {
                         hw_dbg(hw, "EEPROM read failed\n");
-                        break;
+                        return IXGBE_ERR_EEPROM;
                 }
                 checksum += word;
         }
@@ -344,11 +346,11 @@ static u16 ixgbe_calc_eeprom_checksum_X540(struct ixgbe_hw *hw)
          * Include all data from pointers 0x3, 0x6-0xE.  This excludes the
          * FW, PHY module, and PCIe Expansion/Option ROM pointers.
          */
-        for (i = IXGBE_PCIE_ANALOG_PTR; i < IXGBE_FW_PTR; i++) {
+        for (i = ptr_start; i < IXGBE_FW_PTR; i++) {
                 if (i == IXGBE_PHY_PTR || i == IXGBE_OPTION_ROM_PTR)
                         continue;
 
-                if (ixgbe_read_eerd_generic(hw, i, &pointer) != 0) {
+                if (ixgbe_read_eerd_generic(hw, i, &pointer)) {
                         hw_dbg(hw, "EEPROM read failed\n");
                         break;
                 }
@@ -358,8 +360,9 @@ static u16 ixgbe_calc_eeprom_checksum_X540(struct ixgbe_hw *hw)
                     pointer >= hw->eeprom.word_size)
                         continue;
 
-                if (ixgbe_read_eerd_generic(hw, pointer, &length) != 0) {
+                if (ixgbe_read_eerd_generic(hw, pointer, &length)) {
                         hw_dbg(hw, "EEPROM read failed\n");
+                        return IXGBE_ERR_EEPROM;
                         break;
                 }
 
@@ -368,10 +371,10 @@ static u16 ixgbe_calc_eeprom_checksum_X540(struct ixgbe_hw *hw)
                     (pointer + length) >= hw->eeprom.word_size)
                         continue;
 
-                for (j = pointer+1; j <= pointer+length; j++) {
-                        if (ixgbe_read_eerd_generic(hw, j, &word) != 0) {
+                for (j = pointer + 1; j <= pointer + length; j++) {
+                        if (ixgbe_read_eerd_generic(hw, j, &word)) {
                                 hw_dbg(hw, "EEPROM read failed\n");
-                                break;
+                                return IXGBE_ERR_EEPROM;
                         }
                         checksum += word;
                 }
@@ -379,7 +382,7 @@ static u16 ixgbe_calc_eeprom_checksum_X540(struct ixgbe_hw *hw)
 
         checksum = (u16)IXGBE_EEPROM_SUM - checksum;
 
-        return checksum;
+        return (s32)checksum;
 }
 
 /**
@@ -410,23 +413,34 @@ static s32 ixgbe_validate_eeprom_checksum_X540(struct ixgbe_hw *hw,
         if (hw->mac.ops.acquire_swfw_sync(hw, IXGBE_GSSR_EEP_SM))
                 return IXGBE_ERR_SWFW_SYNC;
 
-        checksum = hw->eeprom.ops.calc_checksum(hw);
+        status = hw->eeprom.ops.calc_checksum(hw);
+        if (status < 0)
+                goto out;
+
+        checksum = (u16)(status & 0xffff);
 
         /* Do not use hw->eeprom.ops.read because we do not want to take
          * the synchronization semaphores twice here.
          */
         status = ixgbe_read_eerd_generic(hw, IXGBE_EEPROM_CHECKSUM,
                                          &read_checksum);
+        if (status)
+                goto out;
 
-        hw->mac.ops.release_swfw_sync(hw, IXGBE_GSSR_EEP_SM);
+        /* Verify read checksum from EEPROM is the same as
+         * calculated checksum
+         */
+        if (read_checksum != checksum) {
+                hw_dbg(hw, "Invalid EEPROM checksum");
+                status = IXGBE_ERR_EEPROM_CHECKSUM;
+        }
 
         /* If the user cares, return the calculated checksum */
         if (checksum_val)
                 *checksum_val = checksum;
 
-        /* Verify read and calculated checksums are the same */
-        if (read_checksum != checksum)
-                return IXGBE_ERR_EEPROM_CHECKSUM;
+out:
+        hw->mac.ops.release_swfw_sync(hw, IXGBE_GSSR_EEP_SM);
 
         return status;
 }
@@ -457,15 +471,22 @@ static s32 ixgbe_update_eeprom_checksum_X540(struct ixgbe_hw *hw)
         if (hw->mac.ops.acquire_swfw_sync(hw, IXGBE_GSSR_EEP_SM))
                 return  IXGBE_ERR_SWFW_SYNC;
 
-        checksum = hw->eeprom.ops.calc_checksum(hw);
+        status = hw->eeprom.ops.calc_checksum(hw);
+        if (status < 0)
+                goto out;
+
+        checksum = (u16)(status & 0xffff);
 
         /* Do not use hw->eeprom.ops.write because we do not want to
          * take the synchronization semaphores twice here.
          */
         status = ixgbe_write_eewr_generic(hw, IXGBE_EEPROM_CHECKSUM, checksum);
-        if (!status)
-                status = ixgbe_update_flash_X540(hw);
+        if (status)
+                goto out;
+
+        status = ixgbe_update_flash_X540(hw);
 
+out:
         hw->mac.ops.release_swfw_sync(hw, IXGBE_GSSR_EEP_SM);
         return status;
 }