[tip:x86/urgent] x86/apic: Switch all APICs to Fixed delivery mode

[tip-bot for Thomas Gleixner <tipbot@zytor.com>]

Commit-ID:  45fa8d89192e4e8e801e67dac3394d6597613e07
Gitweb:     https://git.kernel.org/tip/45fa8d89192e4e8e801e67dac3394d6597613e07
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Thu, 28 Dec 2017 11:33:33 +0100
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Fri, 29 Dec 2017 00:21:04 +0100

x86/apic: Switch all APICs to Fixed delivery mode

Some of the APIC incarnations are operating in lowest priority delivery
mode. This worked as long as the vector management code allocated the same
vector on all possible CPUs for each interrupt.

Lowest priority delivery mode does not necessarily respect the affinity
setting and may redirect to some other online CPU. This was documented
somewhere in the old code and the conversion to single target delivery
missed to update the delivery mode of the affected APIC drivers which
results in spurious interrupts on some of the affected CPU/Chipset
combinations.

Switch the APIC drivers over to Fixed delivery mode and remove all
leftovers of lowest priority delivery mode.

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.

Fixes: fdba46ffb4c2 ("x86/apic: Get rid of multi CPU affinity")
Reported-by: vcaputo@pengaru.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: vcaputo@pengaru.com
Cc: Pavel Machek <pavel@ucw.cz>
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1712281140440.1688@nanos
---
 arch/x86/kernel/apic/apic_flat_64.c   | 2 +-
 arch/x86/kernel/apic/apic_noop.c      | 2 +-
 arch/x86/kernel/apic/msi.c            | 8 ++------
 arch/x86/kernel/apic/probe_32.c       | 2 +-
 arch/x86/kernel/apic/x2apic_cluster.c | 2 +-
 drivers/pci/host/pci-hyperv.c         | 8 ++------
 6 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kernel/apic/apic_flat_64.c b/arch/x86/kernel/apic/apic_flat_64.c
index aa85690..25a8702 100644
--- a/arch/x86/kernel/apic/apic_flat_64.c
+++ b/arch/x86/kernel/apic/apic_flat_64.c
@@ -151,7 +151,7 @@ static struct apic apic_flat __ro_after_init = {
 	.apic_id_valid			= default_apic_id_valid,
 	.apic_id_registered		= flat_apic_id_registered,
 
-	.irq_delivery_mode		= dest_LowestPrio,
+	.irq_delivery_mode		= dest_Fixed,
 	.irq_dest_mode			= 1, /* logical */
 
 	.disable_esr			= 0,
diff --git a/arch/x86/kernel/apic/apic_noop.c b/arch/x86/kernel/apic/apic_noop.c
index 7b659c4..5078b5c 100644
--- a/arch/x86/kernel/apic/apic_noop.c
+++ b/arch/x86/kernel/apic/apic_noop.c
@@ -110,7 +110,7 @@ struct apic apic_noop __ro_after_init = {
 	.apic_id_valid			= default_apic_id_valid,
 	.apic_id_registered		= noop_apic_id_registered,
 
-	.irq_delivery_mode		= dest_LowestPrio,
+	.irq_delivery_mode		= dest_Fixed,
 	/* logical delivery broadcast to all CPUs: */
 	.irq_dest_mode			= 1,
 
diff --git a/arch/x86/kernel/apic/msi.c b/arch/x86/kernel/apic/msi.c
index 9b18be7..ce503c9 100644
--- a/arch/x86/kernel/apic/msi.c
+++ b/arch/x86/kernel/apic/msi.c
@@ -39,17 +39,13 @@ static void irq_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
 		((apic->irq_dest_mode == 0) ?
 			MSI_ADDR_DEST_MODE_PHYSICAL :
 			MSI_ADDR_DEST_MODE_LOGICAL) |
-		((apic->irq_delivery_mode != dest_LowestPrio) ?
-			MSI_ADDR_REDIRECTION_CPU :
-			MSI_ADDR_REDIRECTION_LOWPRI) |
+		MSI_ADDR_REDIRECTION_CPU |
 		MSI_ADDR_DEST_ID(cfg->dest_apicid);
 
 	msg->data =
 		MSI_DATA_TRIGGER_EDGE |
 		MSI_DATA_LEVEL_ASSERT |
-		((apic->irq_delivery_mode != dest_LowestPrio) ?
-			MSI_DATA_DELIVERY_FIXED :
-			MSI_DATA_DELIVERY_LOWPRI) |
+		MSI_DATA_DELIVERY_FIXED |
 		MSI_DATA_VECTOR(cfg->vector);
 }
 
diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c
index fa22017..02e8acb 100644
--- a/arch/x86/kernel/apic/probe_32.c
+++ b/arch/x86/kernel/apic/probe_32.c
@@ -105,7 +105,7 @@ static struct apic apic_default __ro_after_init = {
 	.apic_id_valid			= default_apic_id_valid,
 	.apic_id_registered		= default_apic_id_registered,
 
-	.irq_delivery_mode		= dest_LowestPrio,
+	.irq_delivery_mode		= dest_Fixed,
 	/* logical delivery broadcast to all CPUs: */
 	.irq_dest_mode			= 1,
 
diff --git a/arch/x86/kernel/apic/x2apic_cluster.c b/arch/x86/kernel/apic/x2apic_cluster.c
index 622f13c..8b04234 100644
--- a/arch/x86/kernel/apic/x2apic_cluster.c
+++ b/arch/x86/kernel/apic/x2apic_cluster.c
@@ -184,7 +184,7 @@ static struct apic apic_x2apic_cluster __ro_after_init = {
 	.apic_id_valid			= x2apic_apic_id_valid,
 	.apic_id_registered		= x2apic_apic_id_registered,
 
-	.irq_delivery_mode		= dest_LowestPrio,
+	.irq_delivery_mode		= dest_Fixed,
 	.irq_dest_mode			= 1, /* logical */
 
 	.disable_esr			= 0,
diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 0fe3ea1..e7d9447 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -985,9 +985,7 @@ static u32 hv_compose_msi_req_v1(
 	int_pkt->wslot.slot = slot;
 	int_pkt->int_desc.vector = vector;
 	int_pkt->int_desc.vector_count = 1;
-	int_pkt->int_desc.delivery_mode =
-		(apic->irq_delivery_mode == dest_LowestPrio) ?
-			dest_LowestPrio : dest_Fixed;
+	int_pkt->int_desc.delivery_mode = dest_Fixed;
 
 	/*
 	 * Create MSI w/ dummy vCPU set, overwritten by subsequent retarget in
@@ -1008,9 +1006,7 @@ static u32 hv_compose_msi_req_v2(
 	int_pkt->wslot.slot = slot;
 	int_pkt->int_desc.vector = vector;
 	int_pkt->int_desc.vector_count = 1;
-	int_pkt->int_desc.delivery_mode =
-		(apic->irq_delivery_mode == dest_LowestPrio) ?
-			dest_LowestPrio : dest_Fixed;
+	int_pkt->int_desc.delivery_mode = dest_Fixed;
 
 	/*
 	 * Create MSI w/ dummy vCPU set targeting just one vCPU, overwritten