[PATCH v6 3/6] watchdog: iTCO_wdt: cleanup set/unset no_reboot_bit functions

[Kuppuswamy Sathyanarayanan]

iTCO_wdt no_reboot_bit set/unset functions has lot of common code between
them. So merging these two functions into a single update function would
remove these unnecessary code duplications. This patch fixes this issue
by creating a no_reboot_bit update function to handle both set/unset
functions.

Also checking for iTCO version every time you make no_reboot_bit set/unset
call is inefficient and makes the code look complex. This can be improved
by performing this check once during device probe and selecting the
appropriate no_reboot_bit update function. This patch fixes this issue
by splitting the update function into multiple helper functions.

Signed-off-by: Kuppuswamy Sathyanarayanan 

---
 drivers/watchdog/iTCO_wdt.c | 83 +++--
 1 file changed, 50 insertions(+), 33 deletions(-)

Changes since v5:
 * Changed update function argument name from "status" to "set".
 * Fixed commit history.
 * Changed update function name to use "bit" instead of "flag"
 * Addressed Andy's comment on creating multiple helper functions.

diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c
index 3d0abc0..d8768a2 100644
--- a/drivers/watchdog/iTCO_wdt.c
+++ b/drivers/watchdog/iTCO_wdt.c
@@ -106,6 +106,8 @@ struct iTCO_wdt_private {
struct pci_dev *pci_dev;
/* whether or not the watchdog has been suspended */
bool suspended;
+   /* no reboot update function pointer */
+   int (*update_no_reboot_bit)(void *p, bool set);
 };
 
 /* module parameters */
@@ -170,48 +172,61 @@ static inline u32 no_reboot_bit(struct iTCO_wdt_private 
*p)
return enable_bit;
 }
 
-static void iTCO_wdt_set_NO_REBOOT_bit(struct iTCO_wdt_private *p)
+static int inline update_no_reboot_bit_def(void *priv, bool set)
 {
-   u32 val32;
-
-   /* Set the NO_REBOOT bit: this disables reboots */
-   if (p->iTCO_version >= 2) {
-   val32 = readl(p->gcs_pmc);
-   val32 |= no_reboot_bit(p);
-   writel(val32, p->gcs_pmc);
-   } else if (p->iTCO_version == 1) {
-   pci_read_config_dword(p->pci_dev, 0xd4, );
-   val32 |= no_reboot_bit(p);
-   pci_write_config_dword(p->pci_dev, 0xd4, val32);
-   }
+   return 0;
 }
 
-static int iTCO_wdt_unset_NO_REBOOT_bit(struct iTCO_wdt_private *p)
+static int inline update_no_reboot_bit_pci(void *priv, bool set)
 {
-   u32 enable_bit = no_reboot_bit(p);
-   u32 val32 = 0;
+   struct iTCO_wdt_private *p = priv;
+   u32 val32 = 0, newval32 = 0;
 
-   /* Unset the NO_REBOOT bit: this enables reboots */
-   if (p->iTCO_version >= 2) {
-   val32 = readl(p->gcs_pmc);
-   val32 &= ~enable_bit;
-   writel(val32, p->gcs_pmc);
+   pci_read_config_dword(p->pci_dev, 0xd4, );
+   if (set)
+   val32 |= no_reboot_bit(p);
+   else
+   val32 &= ~no_reboot_bit(p);
+   pci_write_config_dword(p->pci_dev, 0xd4, val32);
+   pci_read_config_dword(p->pci_dev, 0xd4, );
 
-   val32 = readl(p->gcs_pmc);
-   } else if (p->iTCO_version == 1) {
-   pci_read_config_dword(p->pci_dev, 0xd4, );
-   val32 &= ~enable_bit;
-   pci_write_config_dword(p->pci_dev, 0xd4, val32);
+   /* make sure the update is successful */
+   if (val32 != newval32)
+   return -EIO;
 
-   pci_read_config_dword(p->pci_dev, 0xd4, );
-   }
+   return 0;
+}
+
+static int inline update_no_reboot_bit_mem(void *priv, bool set)
+{
+   struct iTCO_wdt_private *p = priv;
+   u32 val32 = 0, newval32 = 0;
+
+   val32 = readl(p->gcs_pmc);
+   if (set)
+   val32 |= no_reboot_bit(p);
+   else
+   val32 &= ~no_reboot_bit(p);
+   writel(val32, p->gcs_pmc);
+   newval32 = readl(p->gcs_pmc);
 
-   if (val32 & enable_bit)
+   /* make sure the update is successful */
+   if (val32 != newval32)
return -EIO;
 
return 0;
 }
 
+void iTCO_wdt_no_reboot_bit_setup(struct iTCO_wdt_private *p)
+{
+   if (p->iTCO_version >= 2)
+   p->update_no_reboot_bit = update_no_reboot_bit_mem;
+   else if (p->iTCO_version == 1)
+   p->update_no_reboot_bit = update_no_reboot_bit_pci;
+   else
+   p->update_no_reboot_bit = update_no_reboot_bit_def;
+}
+
 static int iTCO_wdt_start(struct watchdog_device *wd_dev)
 {
struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
@@ -222,7 +237,7 @@ static int iTCO_wdt_start(struct watchdog_device *wd_dev)
iTCO_vendor_pre_start(p->smi_res, wd_dev->timeout);
 
/* disable chipset's NO_REBOOT bit */
-   if (iTCO_wdt_unset_NO_REBOOT_bit(p)) {
+   if (p->update_no_reboot_bit(p, false)) {
spin_unlock(>io_lock);
pr_err("failed to reset NO_REBOOT flag, reboot disabled by 

[PATCH v6 3/6] watchdog: iTCO_wdt: cleanup set/unset no_reboot_bit functions

[Kuppuswamy Sathyanarayanan]

iTCO_wdt no_reboot_bit set/unset functions has lot of common code between
them. So merging these two functions into a single update function would
remove these unnecessary code duplications. This patch fixes this issue
by creating a no_reboot_bit update function to handle both set/unset
functions.

Also checking for iTCO version every time you make no_reboot_bit set/unset
call is inefficient and makes the code look complex. This can be improved
by performing this check once during device probe and selecting the
appropriate no_reboot_bit update function. This patch fixes this issue
by splitting the update function into multiple helper functions.

Signed-off-by: Kuppuswamy Sathyanarayanan 

---
 drivers/watchdog/iTCO_wdt.c | 83 +++--
 1 file changed, 50 insertions(+), 33 deletions(-)

Changes since v5:
 * Changed update function argument name from "status" to "set".
 * Fixed commit history.
 * Changed update function name to use "bit" instead of "flag"
 * Addressed Andy's comment on creating multiple helper functions.

diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c
index 3d0abc0..d8768a2 100644
--- a/drivers/watchdog/iTCO_wdt.c
+++ b/drivers/watchdog/iTCO_wdt.c
@@ -106,6 +106,8 @@ struct iTCO_wdt_private {
struct pci_dev *pci_dev;
/* whether or not the watchdog has been suspended */
bool suspended;
+   /* no reboot update function pointer */
+   int (*update_no_reboot_bit)(void *p, bool set);
 };
 
 /* module parameters */
@@ -170,48 +172,61 @@ static inline u32 no_reboot_bit(struct iTCO_wdt_private 
*p)
return enable_bit;
 }
 
-static void iTCO_wdt_set_NO_REBOOT_bit(struct iTCO_wdt_private *p)
+static int inline update_no_reboot_bit_def(void *priv, bool set)
 {
-   u32 val32;
-
-   /* Set the NO_REBOOT bit: this disables reboots */
-   if (p->iTCO_version >= 2) {
-   val32 = readl(p->gcs_pmc);
-   val32 |= no_reboot_bit(p);
-   writel(val32, p->gcs_pmc);
-   } else if (p->iTCO_version == 1) {
-   pci_read_config_dword(p->pci_dev, 0xd4, );
-   val32 |= no_reboot_bit(p);
-   pci_write_config_dword(p->pci_dev, 0xd4, val32);
-   }
+   return 0;
 }
 
-static int iTCO_wdt_unset_NO_REBOOT_bit(struct iTCO_wdt_private *p)
+static int inline update_no_reboot_bit_pci(void *priv, bool set)
 {
-   u32 enable_bit = no_reboot_bit(p);
-   u32 val32 = 0;
+   struct iTCO_wdt_private *p = priv;
+   u32 val32 = 0, newval32 = 0;
 
-   /* Unset the NO_REBOOT bit: this enables reboots */
-   if (p->iTCO_version >= 2) {
-   val32 = readl(p->gcs_pmc);
-   val32 &= ~enable_bit;
-   writel(val32, p->gcs_pmc);
+   pci_read_config_dword(p->pci_dev, 0xd4, );
+   if (set)
+   val32 |= no_reboot_bit(p);
+   else
+   val32 &= ~no_reboot_bit(p);
+   pci_write_config_dword(p->pci_dev, 0xd4, val32);
+   pci_read_config_dword(p->pci_dev, 0xd4, );
 
-   val32 = readl(p->gcs_pmc);
-   } else if (p->iTCO_version == 1) {
-   pci_read_config_dword(p->pci_dev, 0xd4, );
-   val32 &= ~enable_bit;
-   pci_write_config_dword(p->pci_dev, 0xd4, val32);
+   /* make sure the update is successful */
+   if (val32 != newval32)
+   return -EIO;
 
-   pci_read_config_dword(p->pci_dev, 0xd4, );
-   }
+   return 0;
+}
+
+static int inline update_no_reboot_bit_mem(void *priv, bool set)
+{
+   struct iTCO_wdt_private *p = priv;
+   u32 val32 = 0, newval32 = 0;
+
+   val32 = readl(p->gcs_pmc);
+   if (set)
+   val32 |= no_reboot_bit(p);
+   else
+   val32 &= ~no_reboot_bit(p);
+   writel(val32, p->gcs_pmc);
+   newval32 = readl(p->gcs_pmc);
 
-   if (val32 & enable_bit)
+   /* make sure the update is successful */
+   if (val32 != newval32)
return -EIO;
 
return 0;
 }
 
+void iTCO_wdt_no_reboot_bit_setup(struct iTCO_wdt_private *p)
+{
+   if (p->iTCO_version >= 2)
+   p->update_no_reboot_bit = update_no_reboot_bit_mem;
+   else if (p->iTCO_version == 1)
+   p->update_no_reboot_bit = update_no_reboot_bit_pci;
+   else
+   p->update_no_reboot_bit = update_no_reboot_bit_def;
+}
+
 static int iTCO_wdt_start(struct watchdog_device *wd_dev)
 {
struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
@@ -222,7 +237,7 @@ static int iTCO_wdt_start(struct watchdog_device *wd_dev)
iTCO_vendor_pre_start(p->smi_res, wd_dev->timeout);
 
/* disable chipset's NO_REBOOT bit */
-   if (iTCO_wdt_unset_NO_REBOOT_bit(p)) {
+   if (p->update_no_reboot_bit(p, false)) {
spin_unlock(>io_lock);
pr_err("failed to reset NO_REBOOT flag, reboot disabled by 
hardware/BIOS\n");
return -EIO;
@@