powerpc/pci: Change how re-assigning resouces work

When PCI_REASSIGN_ALL_RSRC is set, we used to clear all bus resources
at the beginning of survey and re-allocate them later.

This changes it so instead, during early fixup, we mark all resources
as IORESOURCE_UNSET and move them down to be 0-based.

Later, if bus resources are still unset at the beginning of the survey,
then we clear them.

This shouldn't impact the re-assignment case on 4xx, but will enable
us to have the platform do some custom resource assignment before the
survey, by clearing individual resources IORESOURCE_UNSET bit.

Also limits the clutter in the kernel log from fixup when re-assigning
since we don't care about the offset applied to the BAR values in this
case.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 36 insertions, 30 deletions

diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index f5b753de3718..8f428fff545f 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -921,18 +921,22 @@ static void __devinit pcibios_fixup_resources(struct pci_dev *dev)
                 struct resource *res = dev->resource + i;
                 if (!res->flags)
                         continue;
-                /* On platforms that have PCI_PROBE_ONLY set, we don't
-                 * consider 0 as an unassigned BAR value. It's technically
-                 * a valid value, but linux doesn't like it... so when we can
-                 * re-assign things, we do so, but if we can't, we keep it
-                 * around and hope for the best...
+
+                /* If we're going to re-assign everything, we mark all resources
+                 * as unset (and 0-base them). In addition, we mark BARs starting
+                 * at 0 as unset as well, except if PCI_PROBE_ONLY is also set
+                 * since in that case, we don't want to re-assign anything
                  */
-                if (res->start == 0 && !pci_has_flag(PCI_PROBE_ONLY)) {
-                        pr_debug("PCI:%s Resource %d %016llx-%016llx [%x] is unassigned\n",
-                                 pci_name(dev), i,
-                                 (unsigned long long)res->start,
-                                 (unsigned long long)res->end,
-                                 (unsigned int)res->flags);
+                if (pci_has_flag(PCI_REASSIGN_ALL_RSRC) ||
+                    (res->start == 0 && !pci_has_flag(PCI_PROBE_ONLY))) {
+                        /* Only print message if not re-assigning */
+                        if (!pci_has_flag(PCI_REASSIGN_ALL_RSRC))
+                                pr_debug("PCI:%s Resource %d %016llx-%016llx [%x] "
+                                         "is unassigned\n",
+                                         pci_name(dev), i,
+                                         (unsigned long long)res->start,
+                                         (unsigned long long)res->end,
+                                         (unsigned int)res->flags);
                         res->end -= res->start;
                         res->start = 0;
                         res->flags |= IORESOURCE_UNSET;
@@ -1042,6 +1046,16 @@ static void __devinit pcibios_fixup_bridge(struct pci_bus *bus)
                 if (i >= 3 && bus->self->transparent)
                         continue;
 
+                /* If we are going to re-assign everything, mark the resource
+                 * as unset and move it down to 0
+                 */
+                if (pci_has_flag(PCI_REASSIGN_ALL_RSRC)) {
+                        res->flags |= IORESOURCE_UNSET;
+                        res->end -= res->start;
+                        res->start = 0;
+                        continue;
+                }
+
                 pr_debug("PCI:%s Bus rsrc %d %016llx-%016llx [%x] fixup...\n",
                          pci_name(dev), i,
                          (unsigned long long)res->start,\
@@ -1262,18 +1276,15 @@ void pcibios_allocate_bus_resources(struct pci_bus *bus)
         pci_bus_for_each_resource(bus, res, i) {
                 if (!res || !res->flags || res->start > res->end || res->parent)
                         continue;
+
+                /* If the resource was left unset at this point, we clear it */
+                if (res->flags & IORESOURCE_UNSET)
+                        goto clear_resource;
+
                 if (bus->parent == NULL)
                         pr = (res->flags & IORESOURCE_IO) ?
                                 &ioport_resource : &iomem_resource;
                 else {
-                        /* Don't bother with non-root busses when
-                         * re-assigning all resources. We clear the
-                         * resource flags as if they were colliding
-                         * and as such ensure proper re-allocation
-                         * later.
-                         */
-                        if (pci_has_flag(PCI_REASSIGN_ALL_RSRC))
-                                goto clear_resource;
                         pr = pci_find_parent_resource(bus->self, res);
                         if (pr == res) {
                                 /* this happens when the generic PCI
@@ -1304,9 +1315,9 @@ void pcibios_allocate_bus_resources(struct pci_bus *bus)
                         if (reparent_resources(pr, res) == 0)
                                 continue;
                 }
-                printk(KERN_WARNING "PCI: Cannot allocate resource region "
-                       "%d of PCI bridge %d, will remap\n", i, bus->number);
-clear_resource:
+                pr_warning("PCI: Cannot allocate resource region "
+                           "%d of PCI bridge %d, will remap\n", i, bus->number);
+        clear_resource:
                 res->start = res->end = 0;
                 res->flags = 0;
         }
@@ -1451,16 +1462,11 @@ void __init pcibios_resource_survey(void)
 {
         struct pci_bus *b;
 
-        /* Allocate and assign resources. If we re-assign everything, then
-         * we skip the allocate phase
-         */
+        /* Allocate and assign resources */
         list_for_each_entry(b, &pci_root_buses, node)
                 pcibios_allocate_bus_resources(b);
-
-        if (!pci_has_flag(PCI_REASSIGN_ALL_RSRC)) {
-                pcibios_allocate_resources(0);
-                pcibios_allocate_resources(1);
-        }
+        pcibios_allocate_resources(0);
+        pcibios_allocate_resources(1);
 
         /* Before we start assigning unassigned resource, we try to reserve
          * the low IO area and the VGA memory area if they intersect the