We have observed the following on Power systems with SR-IOV capable
adapters:
lpfc 0002:01:00.0: device not available because of BAR 7 [0x000000-0x00ffff] collisions
The issue is that on Power systems, PCI BARs cannot be remapped and VF
BARs might have values that collide. As far as I can tell, the current
SR-IOV code cannot be supported on Power and so it seems like we could
provide a hook for an architecture that might set CONFIG_PCI_IOV to
disable SR-IOV support (potentially at run-time).
I defined a weak version of this function that returns true if
CONFIG_PCI_IOV is set (which I think should reflect the current setup
that CONFIG_PCI_IOV represents an unconditional support of SR-IOV) and
false otherwise. The only architecture that implements the hook is
powerpc, which uses a machine callback to decide if a platform supports
SR-IOV or not. I only defined one such callback, for the pseries
platform, and return false unconditionally there.
This was tested to not result in BAR collisions against
3.1.0-rc9-00012-g6367f17.
Signed-off-by: Nishanth Aravamudan <nacc@xxxxxxxxxx>
---
Bjorn, FWIW, this also fixes the issue I was seeing, independent of the
other change, as now the BARs aren't even touched. This is probably a
"safer" change, too, as it doesn't assume that the path I was changing
in the other patches was the only one to be touched for SR-IOV.
diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index 47cacdd..c11618e 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -211,6 +211,8 @@ struct machdep_calls {
* allow assignment/enabling of the device. */
int (*pcibios_enable_device_hook)(struct pci_dev *);
+ bool (*pcibios_supports_sriov)(struct pci_dev *);
+
/* Called to shutdown machine specific hardware not already controlled
* by other drivers.
*/
diff --git a/arch/powerpc/include/asm/pci.h b/arch/powerpc/include/asm/pci.h
index 49c3de5..03dd50f 100644
--- a/arch/powerpc/include/asm/pci.h
+++ b/arch/powerpc/include/asm/pci.h
@@ -192,6 +192,8 @@ extern pgprot_t pci_phys_mem_access_prot(struct file *file,
unsigned long size,
pgprot_t prot);
+extern bool pcibios_supports_sriov(struct pci_dev *);
+
#define HAVE_ARCH_PCI_RESOURCE_TO_USER
extern void pci_resource_to_user(const struct pci_dev *dev, int bar,
const struct resource *rsrc,
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index 32656f1..aefc8a7 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -1732,6 +1732,17 @@ void __devinit pcibios_scan_phb(struct pci_controller *hose)
hose->last_busno = bus->subordinate = pci_scan_child_bus(bus);
}
+bool pcibios_supports_sriov(struct pci_dev *dev)
+{
+#ifdef CONFIG_PCI_IOV
+ if (ppc_md.pcibios_supports_sriov)
+ return ppc_md.pcibios_supports_sriov(dev);
+ return true;
+#else
+ return false;
+#endif
+}
+
static void fixup_hide_host_resource_fsl(struct pci_dev *dev)
{
int i, class = dev->class >> 8;
diff --git a/arch/powerpc/platforms/pseries/pci.c b/arch/powerpc/platforms/pseries/pci.c
index 2c6ded2..3d75308 100644
--- a/arch/powerpc/platforms/pseries/pci.c
+++ b/arch/powerpc/platforms/pseries/pci.c
@@ -76,6 +76,11 @@ void __init pSeries_final_fixup(void)
pci_addr_cache_build();
}
+bool pSeries_supports_sriov(struct pci_dev *dev)
+{
+ return false;
+}
+
/*
* Assume the winbond 82c105 is the IDE controller on a
* p610/p615/p630. We should probably be more careful in case
diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h
index 24c7162..9aeb176 100644
--- a/arch/powerpc/platforms/pseries/pseries.h
+++ b/arch/powerpc/platforms/pseries/pseries.h
@@ -43,6 +43,7 @@ static inline void setup_kexec_cpu_down_mpic(void) { }
#endif
extern void pSeries_final_fixup(void);
+extern bool pSeries_supports_sriov(struct pci_dev *);
/* Poweron flag used for enabling auto ups restart */
extern unsigned long rtas_poweron_auto;
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 0969fd9..f0e9f8f 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -697,6 +697,10 @@ static void pSeries_power_off(void)
#ifndef CONFIG_PCI
void pSeries_final_fixup(void) { }
+bool pSeries_supports_sriov(struct pci_dev *)
+{
+ return false;
+}
#endif
define_machine(pseries) {
@@ -707,6 +711,7 @@ define_machine(pseries) {
.show_cpuinfo = pSeries_show_cpuinfo,
.log_error = pSeries_log_error,
.pcibios_fixup = pSeries_final_fixup,
+ .pcibios_supports_sriov = pSeries_supports_sriov,
.pci_probe_mode = pSeries_pci_probe_mode,
.restart = rtas_restart,
.power_off = pSeries_power_off,
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 42fae47..8f800bd 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -557,6 +557,9 @@ int pci_iov_init(struct pci_dev *dev)
{
int pos;
+ if (!pcibios_supports_sriov(dev))
+ return -ENODEV;
+
if (!pci_is_pcie(dev))
return -ENODEV;
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e9651f0..22c7416 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3330,6 +3330,15 @@ int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type)
return 0;
}
+bool __attribute__((weak)) pcibios_supports_sriov(struct pci_dev *dev)
+{
+#ifdef CONFIG_PCI_IOV
+ return true;
+#else
+ return false;
+#endif
+}
+
/* Some architectures require additional programming to enable VGA */
static arch_set_vga_state_t arch_set_vga_state;
--
Nishanth Aravamudan <nacc@xxxxxxxxxx>
IBM Linux Technology Center
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
