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Subject[PATCH AUTOSEL 4.18 050/131] powerpc/pseries: fix EEH recovery of some IOV devices
Date
From: Sam Bobroff <sbobroff@linux.ibm.com>

[ Upstream commit b87b9cf4935325c98522823caeddd333022a1c62 ]

EEH recovery currently fails on pSeries for some IOV capable PCI
devices, if CONFIG_PCI_IOV is on and the hypervisor doesn't provide
certain device tree properties for the device. (Found on an IOV
capable device using the ipr driver.)

Recovery fails in pci_enable_resources() at the check on r->parent,
because r->flags is set and r->parent is not. This state is due to
sriov_init() setting the start, end and flags members of the IOV BARs
but the parent not being set later in
pseries_pci_fixup_iov_resources(), because the
"ibm,open-sriov-vf-bar-info" property is missing.

Correct this by zeroing the resource flags for IOV BARs when they
can't be configured (this is the same method used by sriov_init() and
__pci_read_base()).

VFs cleared this way can't be enabled later, because that requires
another device tree property, "ibm,number-of-configurable-vfs" as well
as support for the RTAS function "ibm_map_pes". These are all part of
hypervisor support for IOV and it seems unlikely that a hypervisor
would ever partially, but not fully, support it. (None are currently
provided by QEMU/KVM.)

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Reviewed-by: Bryant G. Ly <bryantly@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
arch/powerpc/platforms/pseries/setup.c | 25 +++++++++++++++++--------
1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 8a4868a3964b..cb098e962ffe 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -647,6 +647,15 @@ void of_pci_parse_iov_addrs(struct pci_dev *dev, const int *indexes)
}
}

+static void pseries_disable_sriov_resources(struct pci_dev *pdev)
+{
+ int i;
+
+ pci_warn(pdev, "No hypervisor support for SR-IOV on this device, IOV BARs disabled.\n");
+ for (i = 0; i < PCI_SRIOV_NUM_BARS; i++)
+ pdev->resource[i + PCI_IOV_RESOURCES].flags = 0;
+}
+
static void pseries_pci_fixup_resources(struct pci_dev *pdev)
{
const int *indexes;
@@ -654,10 +663,10 @@ static void pseries_pci_fixup_resources(struct pci_dev *pdev)

/*Firmware must support open sriov otherwise dont configure*/
indexes = of_get_property(dn, "ibm,open-sriov-vf-bar-info", NULL);
- if (!indexes)
- return;
- /* Assign the addresses from device tree*/
- of_pci_set_vf_bar_size(pdev, indexes);
+ if (indexes)
+ of_pci_set_vf_bar_size(pdev, indexes);
+ else
+ pseries_disable_sriov_resources(pdev);
}

static void pseries_pci_fixup_iov_resources(struct pci_dev *pdev)
@@ -669,10 +678,10 @@ static void pseries_pci_fixup_iov_resources(struct pci_dev *pdev)
return;
/*Firmware must support open sriov otherwise dont configure*/
indexes = of_get_property(dn, "ibm,open-sriov-vf-bar-info", NULL);
- if (!indexes)
- return;
- /* Assign the addresses from device tree*/
- of_pci_parse_iov_addrs(pdev, indexes);
+ if (indexes)
+ of_pci_parse_iov_addrs(pdev, indexes);
+ else
+ pseries_disable_sriov_resources(pdev);
}

static resource_size_t pseries_pci_iov_resource_alignment(struct pci_dev *pdev,
--
2.17.1
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