This is a note to let you know that I've just added the patch titled
powerpc/eeh: Wrong place to call pci_get_slot()
to the 3.16-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-eeh-wrong-place-to-call-pci_get_slot.patch
and it can be found in the queue-3.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 9e5c6e5a3be0b2e17ff61b9b74adef4a2c9e6934 Mon Sep 17 00:00:00 2001
From: Mike Qiu <qiudayu@xxxxxxxxxxxxxxxxxx>
Date: Tue, 15 Jul 2014 01:42:22 -0400
Subject: powerpc/eeh: Wrong place to call pci_get_slot()
From: Mike Qiu <qiudayu@xxxxxxxxxxxxxxxxxx>
commit 9e5c6e5a3be0b2e17ff61b9b74adef4a2c9e6934 upstream.
pci_get_slot() is called with hold of PCI bus semaphore and it's not
safe to be called in interrupt context. However, we possibly checks
EEH error and calls the function in interrupt context. To avoid using
pci_get_slot(), we turn into device tree for fetching location code.
Otherwise, we might run into WARN_ON() as following messages indicate:
WARNING: at drivers/pci/search.c:223
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.16.0-rc3+ #72
task: c000000001367af0 ti: c000000001444000 task.ti: c000000001444000
NIP: c000000000497b70 LR: c000000000037530 CTR: 000000003003d114
REGS: c000000001446fa0 TRAP: 0700 Not tainted (3.16.0-rc3+)
MSR: 9000000000029032 <SF,HV,EE,ME,IR,DR,RI> CR: 48002422 XER: 20000000
CFAR: c00000000003752c SOFTE: 0
:
NIP [c000000000497b70] .pci_get_slot+0x40/0x110
LR [c000000000037530] .eeh_pe_loc_get+0x150/0x190
Call Trace:
.of_get_property+0x30/0x60 (unreliable)
.eeh_pe_loc_get+0x150/0x190
.eeh_dev_check_failure+0x1b4/0x550
.eeh_check_failure+0x90/0xf0
.lpfc_sli_check_eratt+0x504/0x7c0 [lpfc]
.lpfc_poll_eratt+0x64/0x100 [lpfc]
.call_timer_fn+0x64/0x190
.run_timer_softirq+0x2cc/0x3e0
Signed-off-by: Mike Qiu <qiudayu@xxxxxxxxxxxxxxxxxx>
Acked-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/eeh_pe.c | 46 ++++++++++++-------------------------------
1 file changed, 13 insertions(+), 33 deletions(-)
--- a/arch/powerpc/kernel/eeh_pe.c
+++ b/arch/powerpc/kernel/eeh_pe.c
@@ -802,53 +802,33 @@ void eeh_pe_restore_bars(struct eeh_pe *
*/
const char *eeh_pe_loc_get(struct eeh_pe *pe)
{
- struct pci_controller *hose;
struct pci_bus *bus = eeh_pe_bus_get(pe);
- struct pci_dev *pdev;
- struct device_node *dn;
- const char *loc;
+ struct device_node *dn = pci_bus_to_OF_node(bus);
+ const char *loc = NULL;
- if (!bus)
- return "N/A";
+ if (!dn)
+ goto out;
/* PHB PE or root PE ? */
if (pci_is_root_bus(bus)) {
- hose = pci_bus_to_host(bus);
- loc = of_get_property(hose->dn,
- "ibm,loc-code", NULL);
- if (loc)
- return loc;
- loc = of_get_property(hose->dn,
- "ibm,io-base-loc-code", NULL);
+ loc = of_get_property(dn, "ibm,loc-code", NULL);
+ if (!loc)
+ loc = of_get_property(dn, "ibm,io-base-loc-code", NULL);
if (loc)
- return loc;
+ goto out;
- pdev = pci_get_slot(bus, 0x0);
- } else {
- pdev = bus->self;
- }
-
- if (!pdev) {
- loc = "N/A";
- goto out;
- }
-
- dn = pci_device_to_OF_node(pdev);
- if (!dn) {
- loc = "N/A";
- goto out;
+ /* Check the root port */
+ dn = dn->child;
+ if (!dn)
+ goto out;
}
loc = of_get_property(dn, "ibm,loc-code", NULL);
if (!loc)
loc = of_get_property(dn, "ibm,slot-location-code", NULL);
- if (!loc)
- loc = "N/A";
out:
- if (pci_is_root_bus(bus) && pdev)
- pci_dev_put(pdev);
- return loc;
+ return loc ? loc : "N/A";
}
/**
Patches currently in stable-queue which might be from qiudayu@xxxxxxxxxxxxxxxxxx are
queue-3.16/powerpc-eeh-wrong-place-to-call-pci_get_slot.patch
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