powerpc/powernv: don't enable SRIOV when VF BAR has non 64bit-prefetchable BAR
On PHB3, we enable SRIOV devices by mapping IOV BAR with M64 BARs. If a
SRIOV device's IOV BAR is not 64bit-prefetchable, this is not assigned from
64bit prefetchable window, which means M64 BAR can't work on it.
The reason is PCI bridges support only 2 memory windows and the kernel code
programs bridges in the way that one window is 32bit-nonprefetchable and
the other one is 64bit-prefetchable. So if devices' IOV BAR is 64bit and
non-prefetchable, it will be mapped into 32bit space and therefore M64
cannot be used for it.
This patch makes this explicit and truncate IOV resource in this case to
save MMIO space.
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 573ae19..58b0e23 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -872,9 +872,6 @@
if (!res->flags || !res->parent)
continue;
- if (!pnv_pci_is_mem_pref_64(res->flags))
- continue;
-
/*
* The actual IOV BAR range is determined by the start address
* and the actual size for num_vfs VFs BAR. This check is to
@@ -903,9 +900,6 @@
if (!res->flags || !res->parent)
continue;
- if (!pnv_pci_is_mem_pref_64(res->flags))
- continue;
-
size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
res2 = *res;
res->start += size * offset;
@@ -1263,9 +1257,6 @@
if (!res->flags || !res->parent)
continue;
- if (!pnv_pci_is_mem_pref_64(res->flags))
- continue;
-
for (j = 0; j < vf_groups; j++) {
do {
win = find_next_zero_bit(&phb->ioda.m64_bar_alloc,
@@ -1552,6 +1543,12 @@
pdn = pci_get_pdn(pdev);
if (phb->type == PNV_PHB_IODA2) {
+ if (!pdn->vfs_expanded) {
+ dev_info(&pdev->dev, "don't support this SRIOV device"
+ " with non 64bit-prefetchable IOV BAR\n");
+ return -ENOSPC;
+ }
+
/* Calculate available PE for required VFs */
mutex_lock(&phb->ioda.pe_alloc_mutex);
pdn->offset = bitmap_find_next_zero_area(
@@ -2877,9 +2874,10 @@
if (!res->flags || res->parent)
continue;
if (!pnv_pci_is_mem_pref_64(res->flags)) {
- dev_warn(&pdev->dev, " non M64 VF BAR%d: %pR\n",
+ dev_warn(&pdev->dev, "Don't support SR-IOV with"
+ " non M64 VF BAR%d: %pR. \n",
i, res);
- continue;
+ goto truncate_iov;
}
size = pci_iov_resource_size(pdev, i + PCI_IOV_RESOURCES);
@@ -2898,11 +2896,6 @@
res = &pdev->resource[i + PCI_IOV_RESOURCES];
if (!res->flags || res->parent)
continue;
- if (!pnv_pci_is_mem_pref_64(res->flags)) {
- dev_warn(&pdev->dev, "Skipping expanding VF BAR%d: %pR\n",
- i, res);
- continue;
- }
dev_dbg(&pdev->dev, " Fixing VF BAR%d: %pR to\n", i, res);
size = pci_iov_resource_size(pdev, i + PCI_IOV_RESOURCES);
@@ -2912,6 +2905,16 @@
i, res, mul);
}
pdn->vfs_expanded = mul;
+
+ return;
+
+truncate_iov:
+ /* To save MMIO space, IOV BAR is truncated. */
+ for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
+ res = &pdev->resource[i + PCI_IOV_RESOURCES];
+ res->flags = 0;
+ res->end = res->start - 1;
+ }
}
#endif /* CONFIG_PCI_IOV */