pci_create_root_bus is called with NULL as parent in ACPI. This
ends up calling pci_bus_assign_domain_nr with a NULL parent, which
crashes when dereferencing parent.
Fix this by providing a way to set the ACPI domain number and ACPI
companion in PCI code. We define pci_acpi_set_companion() to set
the ACPI companion pointer and acpi_pci_get_segment() and to get
the PCI domain number. These functions are stubs for now, the
implementation will be done when the ACPI generic PCI controller
is added.
pci_bus_assign_domain_nr is updated to call acpi_pci_get_segment()
to get the domain number to set on the root bus, in case of ACPI.
Signed-off-by: Jayachandran C <jchandra@xxxxxxxxxxxx>
---
drivers/pci/pci.c | 15 ++++++++++++++-
drivers/pci/probe.c | 2 ++
include/linux/pci-acpi.h | 11 ++++++++++-
3 files changed, 26 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 602eb42..5a3222d 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -20,6 +20,7 @@
#include <linux/string.h>
#include <linux/log2.h>
#include <linux/pci-aspm.h>
+#include <linux/pci-acpi.h>
#include <linux/pm_wakeup.h>
#include <linux/interrupt.h>
#include <linux/device.h>
@@ -4772,9 +4773,21 @@ int pci_get_new_domain_nr(void)
void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent)
{
static int use_dt_domains = -1;
- int domain = of_get_pci_domain_nr(parent->of_node);
+ int domain;
/*
+ * Handle ACPI early
+ *
+ * The companion is not set at this point, and ACPI sets parent to
+ * NULL, we have to try to get the segment from acpi root info.
+ */
+ if (!parent || !parent->of_node) {
+ bus->domain_nr = acpi_pci_get_segment(bus->sysdata);
+ return;
+ }
+
+ domain = of_get_pci_domain_nr(parent->of_node);
+ /*
* Check DT domain and use_dt_domains values.
*
* If DT domain property is valid (domain >= 0) and
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 6d7ab9b..f1faede 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -13,6 +13,7 @@
#include <linux/module.h>
#include <linux/cpumask.h>
#include <linux/pci-aspm.h>
+#include <linux/pci-acpi.h>
#include <linux/aer.h>
#include <linux/acpi.h>
#include <asm-generic/pci-bridge.h>
@@ -2100,6 +2101,7 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
bridge->dev.parent = parent;
bridge->dev.release = pci_release_host_bridge_dev;
dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus);
+ pci_acpi_set_companion(bridge);
error = pcibios_root_bridge_prepare(bridge);
if (error) {
kfree(bridge);
diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
index e9450ef..d410885 100644
--- a/include/linux/pci-acpi.h
+++ b/include/linux/pci-acpi.h
@@ -138,12 +138,21 @@ extern struct list_head pci_mmcfg_list;
#define PCI_MMCFG_BUS_OFFSET(bus) ((bus) << 20)
#define PCI_MMCFG_OFFSET(bus, devfn) ((bus) << 20 | (devfn) << 12)
-
#else /* CONFIG_ACPI */
static inline void acpi_pci_add_bus(struct pci_bus *bus) { }
static inline void acpi_pci_remove_bus(struct pci_bus *bus) { }
#endif /* CONFIG_ACPI */
+static inline void pci_acpi_set_companion(struct pci_host_bridge *bridge)
+{
+ /* leave it to the platform for now */
+}
+
+static inline u16 acpi_pci_get_segment(void *sysdata)
+{
+ return 0;
+}
+
#ifdef CONFIG_ACPI_APEI
extern bool aer_acpi_firmware_first(void);
#else
--
1.9.1
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