powerpc/pnv/pci: Fix incorrect PE reservation attempt on some 64-bit BARs

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>
[mpe: Rename the function as agreed by Ben & Gavin]
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 dedbbe9..fd9444f 100644 (file)
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -111,10 +111,17 @@ 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_m64(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 +236,7 @@ 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_m64(phb, r))
                        continue;
 
                start = _ALIGN_DOWN(r->start - base, sgsz);
@@ -2863,7 +2870,7 @@ 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_m64(phb, res)) {
                        dev_warn(&pdev->dev, "Don't support SR-IOV with"
                                        " non M64 VF BAR%d: %pR. \n",
                                 i, res);
@@ -2958,7 +2965,7 @@ 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_m64(phb, res)) {
                region.start = res->start -
                               phb->hose->mem_offset[0] -
                               phb->ioda.m32_pci_base;
@@ -3083,9 +3090,12 @@ 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 fall 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;
@@ -3125,7 +3135,7 @@ 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_m64(phb, r) &&
                         (type & IORESOURCE_PREFETCH) &&
                         phb->ioda.m64_segsize)
                        w = &hose->mem_resources[1];