[PATCH v4 0/5] Fixing a set of bugs for ioapic hotplug

[PATCH v4 0/5] Fixing a set of bugs for ioapic hotplug

[Rui Wang]

A set of patches fixing bugs found while testing IOAPIC hotplug.

Regards,
Rui

Changelog:

Changes from v3 to v4:
* Rebased on top of 4.8-rc2 and re-tested it.
* Added the missing 'Acked-by: Bjorn Helgaas <bhelgaas@google.com>' in 0002.
* Sent to x86@kernel.org for review as suggested by Rafael.

Changes from v2 to v3:
* Rebased on top of 4.8-rc1 per Bjorn & Rafael.
* Improved the commit message of 0003, w/ clearer explanation.

Changes from v1 to v2:
* Split the first patch into two as advised by Bjorn: "would be nicer if
the interface change and header file munging were in a separate patch so
they wouldn't obscure the meat of the change, i.e., the addition of calls
to acpi_ioapic_add()."
* Removed acpi_ioapic_add() as an exported symbol.
* Fixed some typos, and s/acpi/ACPI/, s/ioapic/IOAPIC/ throughout.
* Fixed a warning from 0-day testing.

Rui Wang (5):
  x86/ioapic: Change prototype of acpi_ioapic_add()
  x86/ioapic: Support hot-removal of IOAPICs present during boot
  x86/ioapic: Fix setup_res() failing to get resource
  x86/ioapic: Fix lost IOAPIC resource after hot-removal and hotadd
  x86/ioapic: Fix ioapic failing to request resource

 drivers/acpi/internal.h |  2 --
 drivers/acpi/ioapic.c   | 46 ++++++++++++++++++++++++++--------------------
 drivers/acpi/pci_root.c | 12 +++++++++++-
 drivers/pci/setup-bus.c |  5 ++++-
 include/linux/acpi.h    |  6 ++++++
 5 files changed, 47 insertions(+), 24 deletions(-)

-- 
1.8.3.1

[PATCH v4 1/5] x86/ioapic: Change prototype of acpi_ioapic_add()

[Rui Wang]

Change the argument of acpi_ioapic_add() to a generic ACPI handle, and
move its prototype from drivers/acpi/internal.h to include/linux/acpi.h
so that it can be called from outside the pci_root driver.

Signed-off-by: Rui Wang <rui.y.wang@intel.com>
---
 drivers/acpi/internal.h | 2 --
 drivers/acpi/ioapic.c   | 6 +++---
 drivers/acpi/pci_root.c | 2 +-
 include/linux/acpi.h    | 6 ++++++
 4 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 940218f..f26fc1d 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -40,10 +40,8 @@ int acpi_sysfs_init(void);
 void acpi_container_init(void);
 void acpi_memory_hotplug_init(void);
 #ifdef	CONFIG_ACPI_HOTPLUG_IOAPIC
-int acpi_ioapic_add(struct acpi_pci_root *root);
 int acpi_ioapic_remove(struct acpi_pci_root *root);
 #else
-static inline int acpi_ioapic_add(struct acpi_pci_root *root) { return 0; }
 static inline int acpi_ioapic_remove(struct acpi_pci_root *root) { return 0; }
 #endif
 #ifdef CONFIG_ACPI_DOCK
diff --git a/drivers/acpi/ioapic.c b/drivers/acpi/ioapic.c
index ccdc8db..2449377 100644
--- a/drivers/acpi/ioapic.c
+++ b/drivers/acpi/ioapic.c
@@ -189,13 +189,13 @@ exit:
 	return AE_OK;
 }
 
-int acpi_ioapic_add(struct acpi_pci_root *root)
+int acpi_ioapic_add(acpi_handle root_handle)
 {
 	acpi_status status, retval = AE_OK;
 
-	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, root->device->handle,
+	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, root_handle,
 				     UINT_MAX, handle_ioapic_add, NULL,
-				     root->device->handle, (void **)&retval);
+				     root_handle, (void **)&retval);
 
 	return ACPI_SUCCESS(status) && ACPI_SUCCESS(retval) ? 0 : -ENODEV;
 }
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index d144168..b07eda1 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -614,7 +614,7 @@ static int acpi_pci_root_add(struct acpi_device *device,
 	if (hotadd) {
 		pcibios_resource_survey_bus(root->bus);
 		pci_assign_unassigned_root_bus_resources(root->bus);
-		acpi_ioapic_add(root);
+		acpi_ioapic_add(root->device->handle);
 	}
 
 	pci_lock_rescan_remove();
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 4d8452c..c9a596b 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -751,6 +751,12 @@ static inline int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
 
 #endif	/* !CONFIG_ACPI */
 
+#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
+int acpi_ioapic_add(acpi_handle root);
+#else
+static inline int acpi_ioapic_add(acpi_handle root) { return 0; }
+#endif
+
 #ifdef CONFIG_ACPI
 void acpi_os_set_prepare_sleep(int (*func)(u8 sleep_state,
 			       u32 pm1a_ctrl,  u32 pm1b_ctrl));
-- 
1.8.3.1

[tip:x86/apic] x86/ioapic: Change prototype of acpi_ioapic_add()

[tip-bot for Rui Wang]

Commit-ID:  fe7bd58f5d25d5d655b1da4a084cc4ef6f085fee
Gitweb:     http://git.kernel.org/tip/fe7bd58f5d25d5d655b1da4a084cc4ef6f085fee
Author:     Rui Wang <rui.y.wang@intel.com>
AuthorDate: Wed, 17 Aug 2016 16:00:33 +0800
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 18 Aug 2016 11:45:18 +0200

x86/ioapic: Change prototype of acpi_ioapic_add()

Change the argument of acpi_ioapic_add() to a generic ACPI handle, and
move its prototype from drivers/acpi/internal.h to include/linux/acpi.h
so that it can be called from outside the pci_root driver.

Signed-off-by: Rui Wang <rui.y.wang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bhelgaas@google.com
Cc: helgaas@kernel.org
Cc: linux-acpi@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: rjw@rjwysocki.net
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/1471420837-31003-2-git-send-email-rui.y.wang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/acpi/internal.h | 2 --
 drivers/acpi/ioapic.c   | 6 +++---
 drivers/acpi/pci_root.c | 2 +-
 include/linux/acpi.h    | 6 ++++++
 4 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 940218f..f26fc1d 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -40,10 +40,8 @@ int acpi_sysfs_init(void);
 void acpi_container_init(void);
 void acpi_memory_hotplug_init(void);
 #ifdef	CONFIG_ACPI_HOTPLUG_IOAPIC
-int acpi_ioapic_add(struct acpi_pci_root *root);
 int acpi_ioapic_remove(struct acpi_pci_root *root);
 #else
-static inline int acpi_ioapic_add(struct acpi_pci_root *root) { return 0; }
 static inline int acpi_ioapic_remove(struct acpi_pci_root *root) { return 0; }
 #endif
 #ifdef CONFIG_ACPI_DOCK
diff --git a/drivers/acpi/ioapic.c b/drivers/acpi/ioapic.c
index ccdc8db..2449377 100644
--- a/drivers/acpi/ioapic.c
+++ b/drivers/acpi/ioapic.c
@@ -189,13 +189,13 @@ exit:
 	return AE_OK;
 }
 
-int acpi_ioapic_add(struct acpi_pci_root *root)
+int acpi_ioapic_add(acpi_handle root_handle)
 {
 	acpi_status status, retval = AE_OK;
 
-	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, root->device->handle,
+	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, root_handle,
 				     UINT_MAX, handle_ioapic_add, NULL,
-				     root->device->handle, (void **)&retval);
+				     root_handle, (void **)&retval);
 
 	return ACPI_SUCCESS(status) && ACPI_SUCCESS(retval) ? 0 : -ENODEV;
 }
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index d144168..b07eda1 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -614,7 +614,7 @@ static int acpi_pci_root_add(struct acpi_device *device,
 	if (hotadd) {
 		pcibios_resource_survey_bus(root->bus);
 		pci_assign_unassigned_root_bus_resources(root->bus);
-		acpi_ioapic_add(root);
+		acpi_ioapic_add(root->device->handle);
 	}
 
 	pci_lock_rescan_remove();
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 4d8452c..c9a596b 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -751,6 +751,12 @@ static inline int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
 
 #endif	/* !CONFIG_ACPI */
 
+#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
+int acpi_ioapic_add(acpi_handle root);
+#else
+static inline int acpi_ioapic_add(acpi_handle root) { return 0; }
+#endif
+
 #ifdef CONFIG_ACPI
 void acpi_os_set_prepare_sleep(int (*func)(u8 sleep_state,
 			       u32 pm1a_ctrl,  u32 pm1b_ctrl));

[PATCH v4 2/5] x86/ioapic: Support hot-removal of IOAPICs present during boot

[Rui Wang]

IOAPICs present during system boot aren't added to ioapic_list,
thus are unable to be hot-removed. Fix it by calling
acpi_ioapic_add() during root bus enumeration.

Signed-off-by: Rui Wang <rui.y.wang@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
---
 drivers/acpi/pci_root.c | 10 ++++++++++
 drivers/pci/setup-bus.c |  5 ++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index b07eda1..bf601d4 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -614,6 +614,16 @@ static int acpi_pci_root_add(struct acpi_device *device,
 	if (hotadd) {
 		pcibios_resource_survey_bus(root->bus);
 		pci_assign_unassigned_root_bus_resources(root->bus);
+		/*
+		 * This is only called for the hotadd case. For the boot-time
+		 * case, we need to wait until after PCI initialization in
+		 * order to deal with IOAPICs mapped in on a PCI BAR.
+		 *
+		 * This is currently x86-specific, because acpi_ioapic_add()
+		 * is an empty function without CONFIG_ACPI_HOTPLUG_IOAPIC.
+		 * And CONFIG_ACPI_HOTPLUG_IOAPIC depends on CONFIG_X86_IO_APIC
+		 * (see drivers/acpi/Kconfig).
+		 */
 		acpi_ioapic_add(root->device->handle);
 	}
 
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index c74059e..ec538d3 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -25,6 +25,7 @@
 #include <linux/ioport.h>
 #include <linux/cache.h>
 #include <linux/slab.h>
+#include <linux/acpi.h>
 #include "pci.h"
 
 unsigned int pci_flags;
@@ -1852,8 +1853,10 @@ void __init pci_assign_unassigned_resources(void)
 {
 	struct pci_bus *root_bus;
 
-	list_for_each_entry(root_bus, &pci_root_buses, node)
+	list_for_each_entry(root_bus, &pci_root_buses, node) {
 		pci_assign_unassigned_root_bus_resources(root_bus);
+		acpi_ioapic_add(ACPI_HANDLE(root_bus->bridge));
+	}
 }
 
 void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
-- 
1.8.3.1

[tip:x86/apic] x86/ioapic: Support hot-removal of IOAPICs present during boot

[tip-bot for Rui Wang]

Commit-ID:  584c5c422f6c749ced1e0bc3c6837f650f64e1e1
Gitweb:     http://git.kernel.org/tip/584c5c422f6c749ced1e0bc3c6837f650f64e1e1
Author:     Rui Wang <rui.y.wang@intel.com>
AuthorDate: Wed, 17 Aug 2016 16:00:34 +0800
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 18 Aug 2016 11:45:18 +0200

x86/ioapic: Support hot-removal of IOAPICs present during boot

IOAPICs present during system boot aren't added to ioapic_list,
thus are unable to be hot-removed. Fix it by calling
acpi_ioapic_add() during root bus enumeration.

Signed-off-by: Rui Wang <rui.y.wang@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: helgaas@kernel.org
Cc: linux-acpi@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: rjw@rjwysocki.net
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/1471420837-31003-3-git-send-email-rui.y.wang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/acpi/pci_root.c | 10 ++++++++++
 drivers/pci/setup-bus.c |  5 ++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index b07eda1..bf601d4 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -614,6 +614,16 @@ static int acpi_pci_root_add(struct acpi_device *device,
 	if (hotadd) {
 		pcibios_resource_survey_bus(root->bus);
 		pci_assign_unassigned_root_bus_resources(root->bus);
+		/*
+		 * This is only called for the hotadd case. For the boot-time
+		 * case, we need to wait until after PCI initialization in
+		 * order to deal with IOAPICs mapped in on a PCI BAR.
+		 *
+		 * This is currently x86-specific, because acpi_ioapic_add()
+		 * is an empty function without CONFIG_ACPI_HOTPLUG_IOAPIC.
+		 * And CONFIG_ACPI_HOTPLUG_IOAPIC depends on CONFIG_X86_IO_APIC
+		 * (see drivers/acpi/Kconfig).
+		 */
 		acpi_ioapic_add(root->device->handle);
 	}
 
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index c74059e..ec538d3 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -25,6 +25,7 @@
 #include <linux/ioport.h>
 #include <linux/cache.h>
 #include <linux/slab.h>
+#include <linux/acpi.h>
 #include "pci.h"
 
 unsigned int pci_flags;
@@ -1852,8 +1853,10 @@ void __init pci_assign_unassigned_resources(void)
 {
 	struct pci_bus *root_bus;
 
-	list_for_each_entry(root_bus, &pci_root_buses, node)
+	list_for_each_entry(root_bus, &pci_root_buses, node) {
 		pci_assign_unassigned_root_bus_resources(root_bus);
+		acpi_ioapic_add(ACPI_HANDLE(root_bus->bridge));
+	}
 }
 
 void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)

[oops] [tip:x86/apic] x86/ioapic: Support hot-removal of IOAPICs present during boot

[Mike Galbraith]

On Thu, 2016-08-18 at 04:02 -0700, tip-bot for Rui Wang wrote:
> Commit-ID:  584c5c422f6c749ced1e0bc3c6837f650f64e1e1
> Gitweb:     
> http://git.kernel.org/tip/584c5c422f6c749ced1e0bc3c6837f650f64e1e1
> Author:     Rui Wang <rui.y.wang@intel.com>
> AuthorDate: Wed, 17 Aug 2016 16:00:34 +0800
> Committer:  Ingo Molnar <mingo@kernel.org>
> CommitDate: Thu, 18 Aug 2016 11:45:18 +0200
> 
> x86/ioapic: Support hot-removal of IOAPICs present during boot
> 
> IOAPICs present during system boot aren't added to ioapic_list,
> thus are unable to be hot-removed. Fix it by calling
> acpi_ioapic_add() during root bus enumeration.

This commit makes tip on my x3550 M3 go boom during boot.  Revert the
series, all is well, start re-applying them, box goes boom at this
commit as below.  Tree is tip v4.8-rc4-312-g5e7dd767889c.

[    2.018042] pci 0000:01:00.0: can't claim BAR 6 [mem 0xfffc0000-0xffffffff pref]: no compatible bridge window
[    2.028010] pci 0000:00:1c.0: BAR 15: assigned [mem 0x90000000-0x901fffff 64bit pref]
[    2.035837] pci 0000:00:01.0: PCI bridge to [bus 0b-0f]
[    2.041063] pci 0000:00:01.0:   bridge window [mem 0x92000000-0x95ffffff]
[    2.047852] pci 0000:00:02.0: PCI bridge to [bus 10-14]
[    2.053082] pci 0000:00:03.0: PCI bridge to [bus 15-19]
[    2.058312] pci 0000:00:07.0: PCI bridge to [bus 1a-1e]
[    2.063544] pci 0000:01:00.0: BAR 6: assigned [mem 0x97980000-0x979bffff pref]
[    2.070766] pci 0000:00:1c.0: PCI bridge to [bus 01-05]
[    2.075991] pci 0000:00:1c.0:   bridge window [io  0x1000-0x1fff]
[    2.082085] pci 0000:00:1c.0:   bridge window [mem 0x97900000-0x979fffff]
[    2.088871] pci 0000:00:1c.0:   bridge window [mem 0x90000000-0x901fffff 64bit pref]
[    2.096615] pci 0000:06:00.0: PCI bridge to [bus 07]
[    2.101586] pci 0000:06:00.0:   bridge window [mem 0x97000000-0x978fffff]
[    2.108372] pci 0000:06:00.0:   bridge window [mem 0x96000000-0x96ffffff pref]
[    2.115597] pci 0000:00:1c.4: PCI bridge to [bus 06-0a]
[    2.120823] pci 0000:00:1c.4:   bridge window [mem 0x97000000-0x978fffff]
[    2.127610] pci 0000:00:1c.4:   bridge window [mem 0x96000000-0x96ffffff 64bit pref]
[    2.135353] pci 0000:00:1e.0: PCI bridge to [bus 1f-23]
[    2.140655] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
[    2.148511] IP: [<ffffffff813e70e7>] acpi_ns_walk_namespace+0x70/0x249
[    2.155055] PGD 0 
[    2.157087] Oops: 0000 [#1] PREEMPT SMP
[    2.160920] Dumping ftrace buffer:
[    2.164322]    (ftrace buffer empty)
[    2.167897] Modules linked in:
[    2.170970] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.8.0-tip+ #27
[    2.177317] Hardware name: IBM System x3550 M3 -[7944K3G]-/69Y5698     , BIOS -[D6E150AUS-1.10]- 12/15/2010
[    2.187044] task: ffff88016ab58000 task.stack: ffffc90000638000
[    2.192955] RIP: 0010:[<ffffffff813e70e7>]  [<ffffffff813e70e7>] acpi_ns_walk_namespace+0x70/0x249
[    2.201923] RSP: 0000:ffffc9000063bd00  EFLAGS: 00010202
[    2.207230] RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000010
[    2.214356] RDX: 000000100000000f RSI: ffffffff81882810 RDI: 00000000000000c8
[    2.221482] RBP: ffffc9000063bd50 R08: ffffffff813fcd89 R09: 0000000000000000
[    2.228606] R10: 0000000000000000 R11: 0000000000000006 R12: 0000000000000000
[    2.235732] R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
[    2.242858] FS:  0000000000000000(0000) GS:ffff88017fc00000(0000) knlGS:0000000000000000
[    2.250939] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    2.256678] CR2: 0000000000000018 CR3: 0000000001c06000 CR4: 00000000000006f0
[    2.263804] Stack:
[    2.265818]  0000000000000000 ffffffff813fcd89 00000001813f5396 ffffffffffffffff
[    2.273283]  0000000000000006 0000000000000000 00000000ffffffff ffffffff813fcd89
[    2.280747]  0000000000000000 0000000000000000 ffffc9000063bda8 ffffffff813e7a7d
[    2.288211] Call Trace:
[    2.290660]  [<ffffffff813fcd89>] ? setup_res+0x94/0x94
[    2.295879]  [<ffffffff813fcd89>] ? setup_res+0x94/0x94
[    2.301100]  [<ffffffff813e7a7d>] acpi_walk_namespace+0xfc/0x14c
[    2.307103]  [<ffffffff81d97356>] ? ras_debugfs_init+0x1b/0x1b
[    2.312931]  [<ffffffff813fd12f>] acpi_ioapic_add+0x39/0x51
[    2.318498]  [<ffffffff81d82b35>] pci_assign_unassigned_resources+0x65/0x6d
[    2.325452]  [<ffffffff81d9736d>] pcibios_assign_resources+0x17/0xb4
[    2.331800]  [<ffffffff81d97356>] ? ras_debugfs_init+0x1b/0x1b
[    2.337629]  [<ffffffff81000450>] do_one_initcall+0x50/0x190
[    2.343284]  [<ffffffff8108e2cb>] ? parse_args+0x27b/0x460
[    2.348768]  [<ffffffff81d43291>] kernel_init_freeable+0x194/0x224
[    2.354943]  [<ffffffff81d429aa>] ? set_debug_rodata+0x12/0x12
[    2.360774]  [<ffffffff81610660>] ? rest_init+0x90/0x90
[    2.365994]  [<ffffffff8161066e>] kernel_init+0xe/0x110
[    2.371215]  [<ffffffff8161c6c5>] ret_from_fork+0x25/0x30
[    2.376607] Code: b8 4c 89 4d b0 e8 af b5 00 00 49 83 fc ff 4c 0f 44 25 fe a2 c8 00 45 31 ed e8 67 b5 00 00 44 89 f0 c7 45 d4 00 00 00 00 83 e0 01 <4d> 8b 7c 24 18 89 45 cc 4d 85 ff 0f 84 97 01 00 00 85 db 0f 84 
[    2.396735] RIP  [<ffffffff813e70e7>] acpi_ns_walk_namespace+0x70/0x249
[    2.403364]  RSP <ffffc9000063bd00>
[    2.406849] CR2: 0000000000000018
[    2.410164] ---[ end trace 6cc1410993da3e1d ]---

(gdb) list *acpi_ns_walk_namespace+0x70
0xffffffff813e70e7 is in acpi_ns_walk_namespace (drivers/acpi/acpica/nswalk.c:79).
74
75              if (!child_node) {
76
77                      /* It's really the parent's _scope_ that we want */
78
79                      return (parent_node->child);
80              }
81
82              /* Otherwise just return the next peer */
83

00:00.0 Host bridge: Intel Corporation 5520 I/O Hub to ESI Port (rev 22)
00:01.0 PCI bridge: Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port 1 (rev 22)
00:02.0 PCI bridge: Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port 2 (rev 22)
00:03.0 PCI bridge: Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port 3 (rev 22)
00:07.0 PCI bridge: Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port 7 (rev 22)
00:10.0 PIC: Intel Corporation 7500/5520/5500/X58 Physical and Link Layer Registers Port 0 (rev 22)
00:10.1 PIC: Intel Corporation 7500/5520/5500/X58 Routing and Protocol Layer Registers Port 0 (rev 22)
00:11.0 PIC: Intel Corporation 7500/5520/5500 Physical and Link Layer Registers Port 1 (rev 22)
00:11.1 PIC: Intel Corporation 7500/5520/5500 Routing & Protocol Layer Register Port 1 (rev 22)
00:14.0 PIC: Intel Corporation 7500/5520/5500/X58 I/O Hub System Management Registers (rev 22)
00:14.1 PIC: Intel Corporation 7500/5520/5500/X58 I/O Hub GPIO and Scratch Pad Registers (rev 22)
00:14.2 PIC: Intel Corporation 7500/5520/5500/X58 I/O Hub Control Status and RAS Registers (rev 22)
00:14.3 PIC: Intel Corporation 7500/5520/5500/X58 I/O Hub Throttle Registers (rev 22)
00:15.0 PIC: Intel Corporation 7500/5520/5500/X58 Trusted Execution Technology Registers (rev 22)
00:16.0 System peripheral: Intel Corporation 5520/5500/X58 Chipset QuickData Technology Device (rev 22)
00:16.1 System peripheral: Intel Corporation 5520/5500/X58 Chipset QuickData Technology Device (rev 22)
00:16.2 System peripheral: Intel Corporation 5520/5500/X58 Chipset QuickData Technology Device (rev 22)
00:16.3 System peripheral: Intel Corporation 5520/5500/X58 Chipset QuickData Technology Device (rev 22)
00:16.4 System peripheral: Intel Corporation 5520/5500/X58 Chipset QuickData Technology Device (rev 22)
00:16.5 System peripheral: Intel Corporation 5520/5500/X58 Chipset QuickData Technology Device (rev 22)
00:16.6 System peripheral: Intel Corporation 5520/5500/X58 Chipset QuickData Technology Device (rev 22)
00:16.7 System peripheral: Intel Corporation 5520/5500/X58 Chipset QuickData Technology Device (rev 22)
00:1a.0 USB controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #4
00:1a.1 USB controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #5
00:1a.7 USB controller: Intel Corporation 82801JI (ICH10 Family) USB2 EHCI Controller #2
00:1c.0 PCI bridge: Intel Corporation 82801JI (ICH10 Family) PCI Express Root Port 1
00:1c.4 PCI bridge: Intel Corporation 82801JI (ICH10 Family) PCI Express Root Port 5
00:1d.0 USB controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #1
00:1d.1 USB controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #2
00:1d.2 USB controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #3
00:1d.7 USB controller: Intel Corporation 82801JI (ICH10 Family) USB2 EHCI Controller #1
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 90)
00:1f.0 ISA bridge: Intel Corporation 82801JIB (ICH10) LPC Interface Controller
00:1f.2 IDE interface: Intel Corporation 82801JI (ICH10 Family) 4 port SATA IDE Controller #1
00:1f.3 SMBus: Intel Corporation 82801JI (ICH10 Family) SMBus Controller
00:1f.5 IDE interface: Intel Corporation 82801JI (ICH10 Family) 2 port SATA IDE Controller #2
01:00.0 RAID bus controller: LSI Logic / Symbios Logic MegaRAID SAS 2108 [Liberator] (rev 03)
06:00.0 PCI bridge: Vitesse Semiconductor VSC452 [SuperBMC] (rev 01)
07:00.0 VGA compatible controller: Matrox Electronics Systems Ltd. MGA G200EV
0b:00.0 Ethernet controller: Broadcom Corporation NetXtreme II BCM5709 Gigabit Ethernet (rev 20)
0b:00.1 Ethernet controller: Broadcom Corporation NetXtreme II BCM5709 Gigabit Ethernet (rev 20)
ff:00.0 Host bridge: Intel Corporation Xeon 5600 Series QuickPath Architecture Generic Non-core Registers (rev 02)
ff:00.1 Host bridge: Intel Corporation Xeon 5600 Series QuickPath Architecture System Address Decoder (rev 02)
ff:02.0 Host bridge: Intel Corporation Xeon 5600 Series QPI Link 0 (rev 02)
ff:02.1 Host bridge: Intel Corporation Xeon 5600 Series QPI Physical 0 (rev 02)
ff:02.2 Host bridge: Intel Corporation Xeon 5600 Series Mirror Port Link 0 (rev 02)
ff:02.3 Host bridge: Intel Corporation Xeon 5600 Series Mirror Port Link 1 (rev 02)
ff:02.4 Host bridge: Intel Corporation Xeon 5600 Series QPI Link 1 (rev 02)
ff:02.5 Host bridge: Intel Corporation Xeon 5600 Series QPI Physical 1 (rev 02)
ff:03.0 Host bridge: Intel Corporation Xeon 5600 Series Integrated Memory Controller Registers (rev 02)
ff:03.1 Host bridge: Intel Corporation Xeon 5600 Series Integrated Memory Controller Target Address Decoder (rev 02)
ff:03.2 Host bridge: Intel Corporation Xeon 5600 Series Integrated Memory Controller RAS Registers (rev 02)
ff:03.4 Host bridge: Intel Corporation Xeon 5600 Series Integrated Memory Controller Test Registers (rev 02)
ff:04.0 Host bridge: Intel Corporation Xeon 5600 Series Integrated Memory Controller Channel 0 Control (rev 02)
ff:04.1 Host bridge: Intel Corporation Xeon 5600 Series Integrated Memory Controller Channel 0 Address (rev 02)
ff:04.2 Host bridge: Intel Corporation Xeon 5600 Series Integrated Memory Controller Channel 0 Rank (rev 02)
ff:04.3 Host bridge: Intel Corporation Xeon 5600 Series Integrated Memory Controller Channel 0 Thermal Control (rev 02)
ff:05.0 Host bridge: Intel Corporation Xeon 5600 Series Integrated Memory Controller Channel 1 Control (rev 02)
ff:05.1 Host bridge: Intel Corporation Xeon 5600 Series Integrated Memory Controller Channel 1 Address (rev 02)
ff:05.2 Host bridge: Intel Corporation Xeon 5600 Series Integrated Memory Controller Channel 1 Rank (rev 02)
ff:05.3 Host bridge: Intel Corporation Xeon 5600 Series Integrated Memory Controller Channel 1 Thermal Control (rev 02)
ff:06.0 Host bridge: Intel Corporation Xeon 5600 Series Integrated Memory Controller Channel 2 Control (rev 02)
ff:06.1 Host bridge: Intel Corporation Xeon 5600 Series Integrated Memory Controller Channel 2 Address (rev 02)
ff:06.2 Host bridge: Intel Corporation Xeon 5600 Series Integrated Memory Controller Channel 2 Rank (rev 02)
ff:06.3 Host bridge: Intel Corporation Xeon 5600 Series Integrated Memory Controller Channel 2 Thermal Control (rev 02)

[PATCH v4 3/5] x86/ioapic: Fix setup_res() failing to get resource

[Rui Wang]

acpi_dev_filter_resource_type() returns 0 on success, and 1 on failure.
A return value of zero means there's a matching resource, so we should
continue within setup_res() to get the resource.

Signed-off-by: Rui Wang <rui.y.wang@intel.com>
---
 drivers/acpi/ioapic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/ioapic.c b/drivers/acpi/ioapic.c
index 2449377..8ab6d42 100644
--- a/drivers/acpi/ioapic.c
+++ b/drivers/acpi/ioapic.c
@@ -46,7 +46,7 @@ static acpi_status setup_res(struct acpi_resource *acpi_res, void *data)
 	struct resource_win win;
 
 	res->flags = 0;
-	if (acpi_dev_filter_resource_type(acpi_res, IORESOURCE_MEM) == 0)
+	if (acpi_dev_filter_resource_type(acpi_res, IORESOURCE_MEM))
 		return AE_OK;
 
 	if (!acpi_dev_resource_memory(acpi_res, res)) {
-- 
1.8.3.1

[tip:x86/apic] x86/ioapic: Fix setup_res() failing to get resource

[tip-bot for Rui Wang]

Commit-ID:  6ab7eba5db93c11d61f6f7fbe21edbc875b26c1a
Gitweb:     http://git.kernel.org/tip/6ab7eba5db93c11d61f6f7fbe21edbc875b26c1a
Author:     Rui Wang <rui.y.wang@intel.com>
AuthorDate: Wed, 17 Aug 2016 16:00:35 +0800
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 18 Aug 2016 11:45:18 +0200

x86/ioapic: Fix setup_res() failing to get resource

acpi_dev_filter_resource_type() returns 0 on success, and 1 on failure.
A return value of zero means there's a matching resource, so we should
continue within setup_res() to get the resource.

Signed-off-by: Rui Wang <rui.y.wang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bhelgaas@google.com
Cc: helgaas@kernel.org
Cc: linux-acpi@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: rjw@rjwysocki.net
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/1471420837-31003-4-git-send-email-rui.y.wang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/acpi/ioapic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/ioapic.c b/drivers/acpi/ioapic.c
index 2449377..8ab6d42 100644
--- a/drivers/acpi/ioapic.c
+++ b/drivers/acpi/ioapic.c
@@ -46,7 +46,7 @@ static acpi_status setup_res(struct acpi_resource *acpi_res, void *data)
 	struct resource_win win;
 
 	res->flags = 0;
-	if (acpi_dev_filter_resource_type(acpi_res, IORESOURCE_MEM) == 0)
+	if (acpi_dev_filter_resource_type(acpi_res, IORESOURCE_MEM))
 		return AE_OK;
 
 	if (!acpi_dev_resource_memory(acpi_res, res)) {

[PATCH v4 4/5] x86/ioapic: Fix lost IOAPIC resource after hot-removal and hotadd

[Rui Wang]

IOAPIC resource at 0xfecxxxxx gets lost from /proc/iomem after
hot-removing and then hot-adding the IOAPIC device.

After system boot, in /proc/iomem:
fec00000-fecfffff : PNP0003:00
  fec00000-fec003ff : IOAPIC 0
  fec01000-fec013ff : IOAPIC 1
  fec40000-fec403ff : IOAPIC 2
  fec80000-fec803ff : IOAPIC 3
  fecc0000-fecc03ff : IOAPIC 4

Then hot-remove IOAPIC 2 and hot-add it again:
fec00000-fecfffff : PNP0003:00
  fec00000-fec003ff : IOAPIC 0
  fec01000-fec013ff : IOAPIC 1
  fec80000-fec803ff : IOAPIC 3
  fecc0000-fecc03ff : IOAPIC 4

The range at 0xfec40000 is lost from /proc/iomem. It is because
handle_ioapic_add() requests resource from either PCI config BAR or
ACPI "_CRS", not both. But Intel platforms map the IOxAPIC registers
both at the PCI config BAR (called MBAR, dynamic), and at the ACPI
"_CRS" (called ABAR, static). The 0xfecX_YZ00 to 0xfecX_YZFF range
appears in "_CRS" of each IOAPIC device. Both ranges should be claimed
from /proc/iomem for exclusive use.

Signed-off-by: Rui Wang <rui.y.wang@intel.com>
---
 drivers/acpi/ioapic.c | 36 ++++++++++++++++++++----------------
 1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/drivers/acpi/ioapic.c b/drivers/acpi/ioapic.c
index 8ab6d42..ee20111 100644
--- a/drivers/acpi/ioapic.c
+++ b/drivers/acpi/ioapic.c
@@ -97,7 +97,7 @@ static acpi_status handle_ioapic_add(acpi_handle handle, u32 lvl,
 	unsigned long long gsi_base;
 	struct acpi_pci_ioapic *ioapic;
 	struct pci_dev *dev = NULL;
-	struct resource *res = NULL;
+	struct resource *res = NULL, *pci_res = NULL, *crs_res;
 	char *type = NULL;
 
 	if (!acpi_is_ioapic(handle, &type))
@@ -137,23 +137,28 @@ static acpi_status handle_ioapic_add(acpi_handle handle, u32 lvl,
 		pci_set_master(dev);
 		if (pci_request_region(dev, 0, type))
 			goto exit_disable;
-		res = &dev->resource[0];
+		pci_res = &dev->resource[0];
 		ioapic->pdev = dev;
 	} else {
 		pci_dev_put(dev);
 		dev = NULL;
+	}
 
-		res = &ioapic->res;
-		acpi_walk_resources(handle, METHOD_NAME__CRS, setup_res, res);
-		if (res->flags == 0) {
-			acpi_handle_warn(handle, "failed to get resource\n");
-			goto exit_free;
-		} else if (request_resource(&iomem_resource, res)) {
-			acpi_handle_warn(handle, "failed to insert resource\n");
-			goto exit_free;
-		}
+	crs_res = &ioapic->res;
+	acpi_walk_resources(handle, METHOD_NAME__CRS, setup_res, crs_res);
+	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)) {
+		acpi_handle_warn(handle, "failed to insert resource\n");
+		goto exit_release;
 	}
 
+	/* try pci resource first, then "_CRS" resource */
+	res = pci_res;
+	if (!res || !res->flags)
+		res = crs_res;
+
 	if (acpi_register_ioapic(handle, res->start, (u32)gsi_base)) {
 		acpi_handle_warn(handle, "failed to register IOAPIC\n");
 		goto exit_release;
@@ -174,14 +179,13 @@ done:
 exit_release:
 	if (dev)
 		pci_release_region(dev, 0);
-	else
-		release_resource(res);
+	if (ioapic->res.flags && ioapic->res.parent)
+		release_resource(&ioapic->res);
 exit_disable:
 	if (dev)
 		pci_disable_device(dev);
 exit_put:
 	pci_dev_put(dev);
-exit_free:
 	kfree(ioapic);
 exit:
 	mutex_unlock(&ioapic_list_lock);
@@ -217,9 +221,9 @@ int acpi_ioapic_remove(struct acpi_pci_root *root)
 			pci_release_region(ioapic->pdev, 0);
 			pci_disable_device(ioapic->pdev);
 			pci_dev_put(ioapic->pdev);
-		} else if (ioapic->res.flags && ioapic->res.parent) {
-			release_resource(&ioapic->res);
 		}
+		if (ioapic->res.flags && ioapic->res.parent)
+			release_resource(&ioapic->res);
 		list_del(&ioapic->list);
 		kfree(ioapic);
 	}
-- 
1.8.3.1

[tip:x86/apic] x86/ioapic: Fix lost IOAPIC resource after hot-removal and hotadd

[tip-bot for Rui Wang]

Commit-ID:  162b83bd5f1d7124e21da78bcf2685b9824d9ef0
Gitweb:     http://git.kernel.org/tip/162b83bd5f1d7124e21da78bcf2685b9824d9ef0
Author:     Rui Wang <rui.y.wang@intel.com>
AuthorDate: Wed, 17 Aug 2016 16:00:36 +0800
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 18 Aug 2016 11:45:18 +0200

x86/ioapic: Fix lost IOAPIC resource after hot-removal and hotadd

IOAPIC resource at 0xfecxxxxx gets lost from /proc/iomem after
hot-removing and then hot-adding the IOAPIC device.

After system boot, in /proc/iomem:

 fec00000-fecfffff : PNP0003:00
   fec00000-fec003ff : IOAPIC 0
   fec01000-fec013ff : IOAPIC 1
   fec40000-fec403ff : IOAPIC 2
   fec80000-fec803ff : IOAPIC 3
   fecc0000-fecc03ff : IOAPIC 4

Then hot-remove IOAPIC 2 and hot-add it again:

 fec00000-fecfffff : PNP0003:00
   fec00000-fec003ff : IOAPIC 0
   fec01000-fec013ff : IOAPIC 1
   fec80000-fec803ff : IOAPIC 3
   fecc0000-fecc03ff : IOAPIC 4

The range at 0xfec40000 is lost from /proc/iomem - which is a bug.

This bug happens because handle_ioapic_add() requests resources from
either PCI config BAR or ACPI "_CRS", not both. But Intel platforms
map the IOxAPIC registers both at the PCI config BAR (called MBAR, dynamic),
and at the ACPI "_CRS" (called ABAR, static). The 0xfecX_YZ00 to 0xfecX_YZFF
range appears in "_CRS" of each IOAPIC device.

Both ranges should be claimed from /proc/iomem for exclusive use.

Signed-off-by: Rui Wang <rui.y.wang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bhelgaas@google.com
Cc: helgaas@kernel.org
Cc: linux-acpi@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: rjw@rjwysocki.net
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/1471420837-31003-5-git-send-email-rui.y.wang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/acpi/ioapic.c | 36 ++++++++++++++++++++----------------
 1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/drivers/acpi/ioapic.c b/drivers/acpi/ioapic.c
index 8ab6d42..ee20111 100644
--- a/drivers/acpi/ioapic.c
+++ b/drivers/acpi/ioapic.c
@@ -97,7 +97,7 @@ static acpi_status handle_ioapic_add(acpi_handle handle, u32 lvl,
 	unsigned long long gsi_base;
 	struct acpi_pci_ioapic *ioapic;
 	struct pci_dev *dev = NULL;
-	struct resource *res = NULL;
+	struct resource *res = NULL, *pci_res = NULL, *crs_res;
 	char *type = NULL;
 
 	if (!acpi_is_ioapic(handle, &type))
@@ -137,23 +137,28 @@ static acpi_status handle_ioapic_add(acpi_handle handle, u32 lvl,
 		pci_set_master(dev);
 		if (pci_request_region(dev, 0, type))
 			goto exit_disable;
-		res = &dev->resource[0];
+		pci_res = &dev->resource[0];
 		ioapic->pdev = dev;
 	} else {
 		pci_dev_put(dev);
 		dev = NULL;
+	}
 
-		res = &ioapic->res;
-		acpi_walk_resources(handle, METHOD_NAME__CRS, setup_res, res);
-		if (res->flags == 0) {
-			acpi_handle_warn(handle, "failed to get resource\n");
-			goto exit_free;
-		} else if (request_resource(&iomem_resource, res)) {
-			acpi_handle_warn(handle, "failed to insert resource\n");
-			goto exit_free;
-		}
+	crs_res = &ioapic->res;
+	acpi_walk_resources(handle, METHOD_NAME__CRS, setup_res, crs_res);
+	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)) {
+		acpi_handle_warn(handle, "failed to insert resource\n");
+		goto exit_release;
 	}
 
+	/* try pci resource first, then "_CRS" resource */
+	res = pci_res;
+	if (!res || !res->flags)
+		res = crs_res;
+
 	if (acpi_register_ioapic(handle, res->start, (u32)gsi_base)) {
 		acpi_handle_warn(handle, "failed to register IOAPIC\n");
 		goto exit_release;
@@ -174,14 +179,13 @@ done:
 exit_release:
 	if (dev)
 		pci_release_region(dev, 0);
-	else
-		release_resource(res);
+	if (ioapic->res.flags && ioapic->res.parent)
+		release_resource(&ioapic->res);
 exit_disable:
 	if (dev)
 		pci_disable_device(dev);
 exit_put:
 	pci_dev_put(dev);
-exit_free:
 	kfree(ioapic);
 exit:
 	mutex_unlock(&ioapic_list_lock);
@@ -217,9 +221,9 @@ int acpi_ioapic_remove(struct acpi_pci_root *root)
 			pci_release_region(ioapic->pdev, 0);
 			pci_disable_device(ioapic->pdev);
 			pci_dev_put(ioapic->pdev);
-		} else if (ioapic->res.flags && ioapic->res.parent) {
-			release_resource(&ioapic->res);
 		}
+		if (ioapic->res.flags && ioapic->res.parent)
+			release_resource(&ioapic->res);
 		list_del(&ioapic->list);
 		kfree(ioapic);
 	}

[PATCH v4 5/5] x86/ioapic: Fix ioapic failing to request resource

[Rui Wang]

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@intel.com>
---
 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;
 	}
-- 
1.8.3.1

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

[tip-bot for Rui Wang]

Commit-ID:  624cad9d2907a0788b56e3ca664c5d7d02645ed4
Gitweb:     http://git.kernel.org/tip/624cad9d2907a0788b56e3ca664c5d7d02645ed4
Author:     Rui Wang <rui.y.wang@intel.com>
AuthorDate: Wed, 17 Aug 2016 16:00:37 +0800
Committer:  Ingo Molnar <mingo@kernel.org>
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@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bhelgaas@google.com
Cc: helgaas@kernel.org
Cc: linux-acpi@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: rjw@rjwysocki.net
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/1471420837-31003-6-git-send-email-rui.y.wang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 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;
 	}