x86/io_apic: Cleanup trigger/polarity helpers

'trigger' and 'polarity' are used throughout the I/O-APIC code for handling
the trigger type (edge/level) and the active low/high configuration. While
there are defines for initializing these variables and struct members, they
are not used consequently and the meaning of 'trigger' and 'polarity' is
opaque and confusing at best.

Rename them to 'is_level' and 'active_low' and make them boolean in various
structs so it's entirely clear what the meaning is.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201024213535.443185-20-dwmw2@infradead.org

arch/x86/include/asm/hw_irq.h

@@ -47,9 +47,9 @@ enum irq_alloc_type {
 struct ioapic_alloc_info {
 	int				pin;
 	int				node;
-	u32				trigger : 1;
-	u32				polarity : 1;
-	u32				valid : 1;
+	u32				is_level	: 1;
+	u32				active_low	: 1;
+	u32				valid		: 1;
 	struct IO_APIC_route_entry	*entry;
 };
 

arch/x86/pci/intel_mid_pci.c

@@ -215,7 +215,7 @@ static int pci_write(struct pci_bus *bus, unsigned int devfn, int where,
 static int intel_mid_pci_irq_enable(struct pci_dev *dev)
 {
 	struct irq_alloc_info info;
-	int polarity;
+	bool polarity_low;
 	int ret;
 	u8 gsi;
 
@@ -230,7 +230,7 @@ static int intel_mid_pci_irq_enable(struct pci_dev *dev)
 
 	switch (intel_mid_identify_cpu()) {
 	case INTEL_MID_CPU_CHIP_TANGIER:
-		polarity = IOAPIC_POL_HIGH;
+		polarity_low = false;
 
 		/* Special treatment for IRQ0 */
 		if (gsi == 0) {
@@ -252,11 +252,11 @@ static int intel_mid_pci_irq_enable(struct pci_dev *dev)
 		}
 		break;
 	default:
-		polarity = IOAPIC_POL_LOW;
+		polarity_low = true;
 		break;
 	}
 
-	ioapic_set_alloc_attr(&info, dev_to_node(&dev->dev), 1, polarity);
+	ioapic_set_alloc_attr(&info, dev_to_node(&dev->dev), 1, polarity_low);
 
 	/*
 	 * MRST only have IOAPIC, the PCI irq lines are 1:1 mapped to

drivers/iommu/amd/iommu.c

@@ -3687,13 +3687,11 @@ static void irq_remapping_prepare_irte(struct amd_ir_data *data,
 		entry = info->ioapic.entry;
 		info->ioapic.entry = NULL;
 		memset(entry, 0, sizeof(*entry));
-		entry->vector        = index;
-		entry->mask          = 0;
-		entry->trigger       = info->ioapic.trigger;
-		entry->polarity      = info->ioapic.polarity;
+		entry->vector	= index;
+		entry->trigger	= info->ioapic.is_level;
+		entry->polarity	= info->ioapic.active_low;
 		/* Mask level triggered irqs. */
-		if (info->ioapic.trigger)
-			entry->mask = 1;
+		entry->mask	= info->ioapic.is_level;
 		break;
 
 	case X86_IRQ_ALLOC_TYPE_HPET:

drivers/iommu/intel/irq_remapping.c

@@ -1306,11 +1306,10 @@ static void intel_irq_remapping_prepare_irte(struct intel_ir_data *data,
 		 * irq handler will do the explicit EOI to the io-apic.
 		 */
 		entry->vector	= info->ioapic.pin;
-		entry->mask	= 0;			/* enable IRQ */
-		entry->trigger	= info->ioapic.trigger;
-		entry->polarity	= info->ioapic.polarity;
-		if (info->ioapic.trigger)
-			entry->mask = 1; /* Mask level triggered irqs. */
+		entry->trigger	= info->ioapic.is_level;
+		entry->polarity	= info->ioapic.active_low;
+		/* Mask level triggered irqs. */
+		entry->mask	= info->ioapic.is_level;
 		break;
 
 	case X86_IRQ_ALLOC_TYPE_HPET: