From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v2] powerpc/pnv/pci: Fix incorrect PE reservation attempt on some 64-bit BARs
Date: Fri, 08 Jul 2016 15:55:43 +1000 [thread overview]
Message-ID: <1467957343.2874.21.camel@kernel.crashing.org> (raw)
The generic allocation code may sometimes decide to assign a prefetchable
64-bit BAR to the M32 window. In fact it may also decide to allocate
a 64-bit non-prefetchable BAR to the M64 one ! So using the resource
flags as a test to decide which window was used for PE allocation is
just wrong and leads to insane PE numbers.
Instead, compare the addresses to figure it out.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: stable@vger.kernel.org
---
v2. Rebased to powerpc/next
arch/powerpc/platforms/powernv/pci-ioda.c | 28 ++++++++++++++++++----------
1 file changed, 18 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index d7477b9..f975d19 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -111,10 +111,16 @@ static int __init iommu_setup(char *str)
}
early_param("iommu", iommu_setup);
-static inline bool pnv_pci_is_mem_pref_64(unsigned long flags)
+static inline bool pnv_pci_is_mem_pref_64(struct pnv_phb *phb, struct resource *r)
{
- return ((flags & (IORESOURCE_MEM_64 | IORESOURCE_PREFETCH)) ==
- (IORESOURCE_MEM_64 | IORESOURCE_PREFETCH));
+ /* WARNING: We cannot rely on the resource flags. The Linux PCI
+ * allocation code sometimes decides to put a 64-bit prefetchable
+ * BAR in the 32-bit window, so we have to compare the addresses.
+ *
+ * For simplicity we only test resource start.
+ */
+ return (r->start >= phb->ioda.m64_base &&
+ r->start < (phb->ioda.m64_base + phb->ioda.m64_size));
}
static struct pnv_ioda_pe *pnv_ioda_init_pe(struct pnv_phb *phb, int pe_no)
@@ -229,7 +235,7 @@ static void pnv_ioda_reserve_dev_m64_pe(struct pci_dev *pdev,
sgsz = phb->ioda.m64_segsize;
for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
r = &pdev->resource[i];
- if (!r->parent || !pnv_pci_is_mem_pref_64(r->flags))
+ if (!r->parent || !pnv_pci_is_mem_pref_64(phb, r))
continue;
start = _ALIGN_DOWN(r->start - base, sgsz);
@@ -3014,7 +3020,7 @@ static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev)
res = &pdev->resource[i + PCI_IOV_RESOURCES];
if (!res->flags || res->parent)
continue;
- if (!pnv_pci_is_mem_pref_64(res->flags)) {
+ if (!pnv_pci_is_mem_pref_64(phb, res)) {
dev_warn(&pdev->dev, "Don't support SR-IOV with"
" non M64 VF BAR%d: %pR. \n",
i, res);
@@ -3109,7 +3115,7 @@ static void pnv_ioda_setup_pe_res(struct pnv_ioda_pe *pe,
index++;
}
} else if ((res->flags & IORESOURCE_MEM) &&
- !pnv_pci_is_mem_pref_64(res->flags)) {
+ !pnv_pci_is_mem_pref_64(phb, res)) {
region.start = res->start -
phb->hose->mem_offset[0] -
phb->ioda.m32_pci_base;
@@ -3234,9 +3240,11 @@ static resource_size_t pnv_pci_window_alignment(struct pci_bus *bus,
bridge = bridge->bus->self;
}
- /* We fail back to M32 if M64 isn't supported */
- if (phb->ioda.m64_segsize &&
- pnv_pci_is_mem_pref_64(type))
+ /* We fail back to M32 if M64 isn't supported. We enforce the M64
+ * alignment for any 64-bit resource, PCIe doesn't care and
+ * bridges only do 64-bit prefetchable anyway
+ */
+ if (phb->ioda.m64_segsize && (type & IORESOURCE_MEM_64))
return phb->ioda.m64_segsize;
if (type & IORESOURCE_MEM)
return phb->ioda.m32_segsize;
@@ -3276,7 +3284,7 @@ static void pnv_pci_fixup_bridge_resources(struct pci_bus *bus,
w = NULL;
if (r->flags & type & IORESOURCE_IO)
w = &hose->io_resource;
- else if (pnv_pci_is_mem_pref_64(r->flags) &&
+ else if (pnv_pci_is_mem_pref_64(phb, r) &&
(type & IORESOURCE_PREFETCH) &&
phb->ioda.m64_segsize)
w = &hose->mem_resources[1];
next reply other threads:[~2016-07-08 5:55 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-08 5:55 Benjamin Herrenschmidt [this message]
2016-08-10 12:46 ` [v2] powerpc/pnv/pci: Fix incorrect PE reservation attempt on some 64-bit BARs Michael Ellerman
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