[PATCH v5 3/4] PCI: Handle IORESOURCE_PCI_FIXED when sizing and assigning resources.

From: David Daney
Date: Tue Oct 06 2015 - 19:51:37 EST


From: David Daney <david.daney@xxxxxxxxxx>

The new Enhanced Allocation (EA) capability support creates resources
with the IORESOURCE_PCI_FIXED set. This causes a couple of problems:

1) Since these resources cannot be relocated or resized, their
alignment is not really defined, and it is therefore not specified.
This causes a problem in pbus_size_mem() where resources with
unspecified alignment are disabled.

2) During resource assignment in pci_bus_assign_resources(),
IORESOURCE_PCI_FIXED resources are not given a parent. This, in
turn, causes pci_enable_resources() to fail with a "not claimed"
error.

So, in pbus_size_mem() skip IORESOURCE_PCI_FIXED resources, instead of
disabling them.

In __pci_bus_assign_resources(), for IORESOURCE_PCI_FIXED resources,
try to request the resource from a parent bus.

Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
---
drivers/pci/setup-bus.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 47 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 508cc56..7239a2c 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1037,9 +1037,10 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
struct resource *r = &dev->resource[i];
resource_size_t r_size;

- if (r->parent || ((r->flags & mask) != type &&
- (r->flags & mask) != type2 &&
- (r->flags & mask) != type3))
+ if (r->parent || (r->flags | IORESOURCE_PCI_FIXED) ||
+ ((r->flags & mask) != type &&
+ (r->flags & mask) != type2 &&
+ (r->flags & mask) != type3))
continue;
r_size = resource_size(r);
#ifdef CONFIG_PCI_IOV
@@ -1340,6 +1341,47 @@ void pci_bus_size_bridges(struct pci_bus *bus)
}
EXPORT_SYMBOL(pci_bus_size_bridges);

+static void assign_fixed_resource_on_bus(struct pci_bus *b, struct resource *r)
+{
+ int i;
+ struct resource *parent_r;
+ unsigned long mask = IORESOURCE_IO | IORESOURCE_MEM |
+ IORESOURCE_PREFETCH;
+
+ pci_bus_for_each_resource(b, parent_r, i) {
+ if (!parent_r)
+ continue;
+
+ if ((r->flags & mask) == (parent_r->flags & mask) &&
+ resource_contains(parent_r, r))
+ request_resource(parent_r, r);
+ }
+}
+
+/*
+ * Try to assign any resources marked as IORESOURCE_PCI_FIXED, as they
+ * are skipped by pbus_assign_resources_sorted().
+ */
+static void pdev_assign_fixed_resources(struct pci_dev *dev)
+{
+ int i;
+
+ for (i = 0; i < PCI_NUM_RESOURCES; i++) {
+ struct pci_bus *b;
+ struct resource *r = &dev->resource[i];
+
+ if (r->parent || !(r->flags & IORESOURCE_PCI_FIXED) ||
+ !(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
+ continue;
+
+ b = dev->bus;
+ while (b && !r->parent) {
+ assign_fixed_resource_on_bus(b, r);
+ b = b->parent;
+ }
+ }
+}
+
void __pci_bus_assign_resources(const struct pci_bus *bus,
struct list_head *realloc_head,
struct list_head *fail_head)
@@ -1350,6 +1392,8 @@ void __pci_bus_assign_resources(const struct pci_bus *bus,
pbus_assign_resources_sorted(bus, realloc_head, fail_head);

list_for_each_entry(dev, &bus->devices, bus_list) {
+ pdev_assign_fixed_resources(dev);
+
b = dev->subordinate;
if (!b)
continue;
--
1.9.1

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