x86/apic: Drop apic::delivery_mode

This field is set to APIC_DELIVERY_MODE_FIXED in all cases, and is read
exactly once. Fold the constant in uv_program_mmr() and drop the field.

Searching for the origin of the stale HyperV comment reveals commit
a31e58e129f7 ("x86/apic: Switch all APICs to Fixed delivery mode") which
notes:

As a consequence of this change, the apic::irq_delivery_mode field is
now pointless, but this needs to be cleaned up in a separate patch.

6 years is long enough for this technical debt to have survived.

[ bp: Fold in
https://lore.kernel.org/r/[e-mail]
]

Signed-off-by: Andrew Cooper <[e-mail]>
Signed-off-by: Thomas Gleixner <[e-mail]>
Signed-off-by: Borislav Petkov (AMD) <[e-mail]>
Reviewed-by: Steve Wahl <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/x86/include/asm/apic.h

···
 	void	(*send_IPI_all)(int vector);
 	void	(*send_IPI_self)(int vector);
 
-	enum apic_delivery_modes delivery_mode;
-
 	u32	disable_esr		: 1,
 		dest_mode_logical	: 1,
 		x2apic_set_max_apicid	: 1,

arch/x86/kernel/apic/apic_flat_64.c

···
 	.acpi_madt_oem_check		= flat_acpi_madt_oem_check,
 	.apic_id_registered		= default_apic_id_registered,
 
-	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
 	.dest_mode_logical		= true,
 
 	.disable_esr			= 0,
···
 	.acpi_madt_oem_check		= physflat_acpi_madt_oem_check,
 	.apic_id_registered		= default_apic_id_registered,
 
-	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
 	.dest_mode_logical		= false,
 
 	.disable_esr			= 0,

arch/x86/kernel/apic/apic_noop.c

···
 struct apic apic_noop __ro_after_init = {
 	.name				= "noop",
 
-	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
 	.dest_mode_logical		= true,
 
 	.disable_esr			= 0,

arch/x86/kernel/apic/apic_numachip.c

···
 	.probe				= numachip1_probe,
 	.acpi_madt_oem_check		= numachip1_acpi_madt_oem_check,
 
-	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
 	.dest_mode_logical		= false,
 
 	.disable_esr			= 0,
···
 	.probe				= numachip2_probe,
 	.acpi_madt_oem_check		= numachip2_acpi_madt_oem_check,
 
-	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
 	.dest_mode_logical		= false,
 
 	.disable_esr			= 0,

arch/x86/kernel/apic/bigsmp_32.c

···
 	.name				= "bigsmp",
 	.probe				= probe_bigsmp,
 
-	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
 	.dest_mode_logical		= false,
 
 	.disable_esr			= 1,

arch/x86/kernel/apic/probe_32.c

···
 	.probe				= probe_default,
 	.apic_id_registered		= default_apic_id_registered,
 
-	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
 	.dest_mode_logical		= true,
 
 	.disable_esr			= 0,

arch/x86/kernel/apic/x2apic_cluster.c

···
 	.probe				= x2apic_cluster_probe,
 	.acpi_madt_oem_check		= x2apic_acpi_madt_oem_check,
 
-	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
 	.dest_mode_logical		= true,
 
 	.disable_esr			= 0,

arch/x86/kernel/apic/x2apic_phys.c

···
 	.probe				= x2apic_phys_probe,
 	.acpi_madt_oem_check		= x2apic_acpi_madt_oem_check,
 
-	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
 	.dest_mode_logical		= false,
 
 	.disable_esr			= 0,

arch/x86/kernel/apic/x2apic_uv_x.c

···
 	.probe				= uv_probe,
 	.acpi_madt_oem_check		= uv_acpi_madt_oem_check,
 
-	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
 	.dest_mode_logical		= false,
 
 	.disable_esr			= 0,

arch/x86/platform/uv/uv_irq.c

···
 	mmr_value = 0;
 	entry = (struct uv_IO_APIC_route_entry *)&mmr_value;
 	entry->vector		= cfg->vector;
-	entry->delivery_mode	= apic->delivery_mode;
+	entry->delivery_mode	= APIC_DELIVERY_MODE_FIXED;
 	entry->dest_mode	= apic->dest_mode_logical;
 	entry->polarity		= 0;
 	entry->trigger		= 0;

drivers/iommu/amd/iommu.c

···
 
 	data->irq_2_irte.devid = devid;
 	data->irq_2_irte.index = index + sub_handle;
-	iommu->irte_ops->prepare(data->entry, apic->delivery_mode,
+	iommu->irte_ops->prepare(data->entry, APIC_DELIVERY_MODE_FIXED,
 				 apic->dest_mode_logical, irq_cfg->vector,
 				 irq_cfg->dest_apicid, devid);
 
···
 
 	entry->lo.fields_remap.valid       = valid;
 	entry->lo.fields_remap.dm          = apic->dest_mode_logical;
-	entry->lo.fields_remap.int_type    = apic->delivery_mode;
+	entry->lo.fields_remap.int_type    = APIC_DELIVERY_MODE_FIXED;
 	entry->hi.fields.vector            = cfg->vector;
 	entry->lo.fields_remap.destination =
 				APICID_TO_IRTE_DEST_LO(cfg->dest_apicid);

drivers/iommu/intel/irq_remapping.c

···
 	 * irq migration in the presence of interrupt-remapping.
 	*/
 	irte->trigger_mode = 0;
-	irte->dlvry_mode = apic->delivery_mode;
+	irte->dlvry_mode = APIC_DELIVERY_MODE_FIXED;
 	irte->vector = vector;
 	irte->dest_id = IRTE_DEST(dest);
 	irte->redir_hint = 1;

drivers/pci/controller/pci-hyperv.c

···
 			   PCI_FUNC(pdev->devfn);
 	params->int_target.vector = hv_msi_get_int_vector(data);
 
-	/*
-	 * Honoring apic->delivery_mode set to APIC_DELIVERY_MODE_FIXED by
-	 * setting the HV_DEVICE_INTERRUPT_TARGET_MULTICAST flag results in a
-	 * spurious interrupt storm. Not doing so does not seem to have a
-	 * negative effect (yet?).
-	 */
-
 	if (hbus->protocol_version >= PCI_PROTOCOL_VERSION_1_2) {
 		/*
 		 * PCI_PROTOCOL_VERSION_1_2 supports the VP_SET version of the