PCI/MSI: Use bool for MSI enable state tracking

Convert pci_msi_enable and pci_msi_enabled() to use bool type for clarity.
No functional changes, only code cleanup.

Signed-off-by: Hans Zhang <hans.zhang@cixtech.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250516165223.125083-2-18255117159@163.com

Author: Hans Zhang

drivers/pci/msi/api.c

@@ -399,7 +399,7 @@ EXPORT_SYMBOL_GPL(pci_restore_msi_state);
  * Return: true if MSI has not been globally disabled through ACPI FADT,
  * PCI bridge quirks, or the "pci=nomsi" kernel command-line option.
  */
-int pci_msi_enabled(void)
+bool pci_msi_enabled(void)
 {
 	return pci_msi_enable;
 }

drivers/pci/msi/msi.c

@@ -15,7 +15,7 @@
 #include "../pci.h"
 #include "msi.h"
 
-int pci_msi_enable = 1;
+bool pci_msi_enable = true;
 
 /**
  * pci_msi_supported - check whether MSI may be enabled on a device
@@ -970,5 +970,5 @@ EXPORT_SYMBOL(msi_desc_to_pci_dev);
 
 void pci_no_msi(void)
 {
-	pci_msi_enable = 0;
+	pci_msi_enable = false;
 }

drivers/pci/msi/msi.h

@@ -87,7 +87,7 @@ static inline __attribute_const__ u32 msi_multi_mask(struct msi_desc *desc)
 void msix_prepare_msi_desc(struct pci_dev *dev, struct msi_desc *desc);
 
 /* Subsystem variables */
-extern int pci_msi_enable;
+extern bool pci_msi_enable;
 
 /* MSI internal functions invoked from the public APIs */
 void pci_msi_shutdown(struct pci_dev *dev);

include/linux/pci.h

@@ -1669,7 +1669,7 @@ void pci_disable_msi(struct pci_dev *dev);
 int pci_msix_vec_count(struct pci_dev *dev);
 void pci_disable_msix(struct pci_dev *dev);
 void pci_restore_msi_state(struct pci_dev *dev);
-int pci_msi_enabled(void);
+bool pci_msi_enabled(void);
 int pci_enable_msi(struct pci_dev *dev);
 int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
 			  int minvec, int maxvec);
@@ -1702,7 +1702,7 @@ static inline void pci_disable_msi(struct pci_dev *dev) { }
 static inline int pci_msix_vec_count(struct pci_dev *dev) { return -ENOSYS; }
 static inline void pci_disable_msix(struct pci_dev *dev) { }
 static inline void pci_restore_msi_state(struct pci_dev *dev) { }
-static inline int pci_msi_enabled(void) { return 0; }
+static inline bool pci_msi_enabled(void) { return false; }
 static inline int pci_enable_msi(struct pci_dev *dev)
 { return -ENOSYS; }
 static inline int pci_enable_msix_range(struct pci_dev *dev,