[tip:x86/apic] x86/ioapic: Fix IOAPIC failing to request resource

From: tip-bot for Rui Wang
Date: Thu Aug 18 2016 - 07:04:11 EST


Commit-ID: 624cad9d2907a0788b56e3ca664c5d7d02645ed4
Gitweb: http://git.kernel.org/tip/624cad9d2907a0788b56e3ca664c5d7d02645ed4
Author: Rui Wang <rui.y.wang@xxxxxxxxx>
AuthorDate: Wed, 17 Aug 2016 16:00:37 +0800
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 18 Aug 2016 11:45:19 +0200

x86/ioapic: Fix IOAPIC failing to request resource

handle_ioapic_add() uses request_resource() to request ACPI "_CRS"
resources. This can fail with the following error message:

[ 247.325693] ACPI: \_SB_.IIO1.AID1: failed to insert resource

This happens when there are multiple IOAPICs and DSDT groups their
"_CRS" resources as the children of a parent resource, as seen from
/proc/iomem:

fec00000-fecfffff : PNP0003:00
fec00000-fec003ff : IOAPIC 0
fec01000-fec013ff : IOAPIC 1
fec40000-fec403ff : IOAPIC 2

In this case request_resource() fails because there's a conflicting
resource which is the parent (fec0000-fecfffff). Fix it by using
insert_resource() which can request resources by taking the conflicting
resource as the parent.

Signed-off-by: Rui Wang <rui.y.wang@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: bhelgaas@xxxxxxxxxx
Cc: helgaas@xxxxxxxxxx
Cc: linux-acpi@xxxxxxxxxxxxxxx
Cc: linux-pci@xxxxxxxxxxxxxxx
Cc: rjw@xxxxxxxxxxxxx
Cc: tony.luck@xxxxxxxxx
Link: http://lkml.kernel.org/r/1471420837-31003-6-git-send-email-rui.y.wang@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
drivers/acpi/ioapic.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/ioapic.c b/drivers/acpi/ioapic.c
index ee20111..6d7ce6e 100644
--- a/drivers/acpi/ioapic.c
+++ b/drivers/acpi/ioapic.c
@@ -146,10 +146,12 @@ static acpi_status handle_ioapic_add(acpi_handle handle, u32 lvl,

crs_res = &ioapic->res;
acpi_walk_resources(handle, METHOD_NAME__CRS, setup_res, crs_res);
+ crs_res->name = type;
+ crs_res->flags |= IORESOURCE_BUSY;
if (crs_res->flags == 0) {
acpi_handle_warn(handle, "failed to get resource\n");
goto exit_release;
- } else if (request_resource(&iomem_resource, crs_res)) {
+ } else if (insert_resource(&iomem_resource, crs_res)) {
acpi_handle_warn(handle, "failed to insert resource\n");
goto exit_release;
}