[PATCH 4/5 v3] PCI: make cardbus-bridge resources optional

From: Ram Pai
Date: Mon Jul 25 2011 - 16:09:56 EST


Allocate resources to cardbus bridge only after all other genuine
resources requests are satisfied. Dont retry if resource allocation
for cardbus-bridges fail.

Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx>
---
drivers/pci/pci.h | 4 ++++
drivers/pci/setup-bus.c | 41 ++++++++++++++++++++++++++++++++---------
2 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 3a39bf1..2b3f60b 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -285,6 +285,8 @@ static inline int pci_iov_bus_range(struct pci_bus *bus)

#endif /* CONFIG_PCI_IOV */

+extern unsigned long pci_cardbus_resource_alignment(struct resource *);
+
static inline resource_size_t pci_resource_alignment(struct pci_dev *dev,
struct resource *res)
{
@@ -294,6 +296,8 @@ static inline resource_size_t pci_resource_alignment(struct pci_dev *dev,
if (resno >= PCI_IOV_RESOURCES && resno <= PCI_IOV_RESOURCE_END)
return pci_sriov_resource_alignment(dev, resno);
#endif
+ if (dev->class >> 8 == PCI_CLASS_BRIDGE_CARDBUS)
+ return pci_cardbus_resource_alignment(res);
return resource_alignment(res);
}

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 3ac64d6..6775d5f 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -164,6 +164,7 @@ static void adjust_resources_sorted(struct resource_list_x *add_head,
idx = res - &list->dev->resource[0];
add_size=list->add_size;
if (!resource_size(res)) {
+ res->start = list->start;
res->end = res->start + add_size - 1;
if(pci_assign_resource(list->dev, idx))
reset_resource(res);
@@ -223,7 +224,7 @@ static void __assign_resources_sorted(struct resource_list *head,
/* Satisfy the must-have resource requests */
assign_requested_resources_sorted(head, fail_head);

- /* Try to satisfy any additional nice-to-have resource
+ /* Try to satisfy any additional optional resource
requests */
if (add_head)
adjust_resources_sorted(add_head, head);
@@ -681,7 +682,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
if (add_head && i >= PCI_IOV_RESOURCES &&
i <= PCI_IOV_RESOURCE_END) {
r->end = r->start - 1;
- add_to_list(add_head, dev, r, r_size, 1);
+ add_to_list(add_head, dev, r, r_size, 0/* dont' care */);
children_add_size += r_size;
continue;
}
@@ -746,7 +747,17 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
return 1;
}

-static void pci_bus_size_cardbus(struct pci_bus *bus)
+unsigned long pci_cardbus_resource_alignment(struct resource *res)
+{
+ if (res->flags & IORESOURCE_IO)
+ return pci_cardbus_io_size;
+ if (res->flags & IORESOURCE_MEM)
+ return pci_cardbus_mem_size;
+ return 0;
+}
+
+static void pci_bus_size_cardbus(struct pci_bus *bus,
+ struct resource_list_x *add_head)
{
struct pci_dev *bridge = bus->self;
struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
@@ -757,12 +768,14 @@ static void pci_bus_size_cardbus(struct pci_bus *bus)
* a fixed amount of bus space for CardBus bridges.
*/
b_res[0].start = 0;
- b_res[0].end = pci_cardbus_io_size - 1;
b_res[0].flags |= IORESOURCE_IO | IORESOURCE_SIZEALIGN;
+ if (add_head)
+ add_to_list(add_head, bridge, b_res, pci_cardbus_io_size, 0 /* dont care */);

b_res[1].start = 0;
- b_res[1].end = pci_cardbus_io_size - 1;
b_res[1].flags |= IORESOURCE_IO | IORESOURCE_SIZEALIGN;
+ if (add_head)
+ add_to_list(add_head, bridge, b_res+1, pci_cardbus_io_size, 0 /* dont care */);

/*
* Check whether prefetchable memory is supported
@@ -782,17 +795,27 @@ static void pci_bus_size_cardbus(struct pci_bus *bus)
*/
if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0) {
b_res[2].start = 0;
- b_res[2].end = pci_cardbus_mem_size - 1;
b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH | IORESOURCE_SIZEALIGN;
+ if (add_head)
+ add_to_list(add_head, bridge, b_res+2, pci_cardbus_mem_size, 0 /* dont care */);

b_res[3].start = 0;
- b_res[3].end = pci_cardbus_mem_size - 1;
b_res[3].flags |= IORESOURCE_MEM | IORESOURCE_SIZEALIGN;
+ if (add_head)
+ add_to_list(add_head, bridge, b_res+3, pci_cardbus_mem_size, 0 /* dont care */);
} else {
b_res[3].start = 0;
- b_res[3].end = pci_cardbus_mem_size * 2 - 1;
b_res[3].flags |= IORESOURCE_MEM | IORESOURCE_SIZEALIGN;
+ if (add_head)
+ add_to_list(add_head, bridge, b_res+3, pci_cardbus_mem_size * 2, 0 /* dont care */);
}
+
+ /* set the size of the resource to zero, so that the resource does not
+ * get assigned during required-resource allocation cycle but gets assigned
+ * during the optional-resource allocation cycle.
+ */
+ b_res[0].start = b_res[1].start = b_res[2].start = b_res[3].start = 1;
+ b_res[0].end = b_res[1].end = b_res[2].end = b_res[3].end = 0;
}

void __ref __pci_bus_size_bridges(struct pci_bus *bus,
@@ -809,7 +832,7 @@ void __ref __pci_bus_size_bridges(struct pci_bus *bus,

switch (dev->class >> 8) {
case PCI_CLASS_BRIDGE_CARDBUS:
- pci_bus_size_cardbus(b);
+ pci_bus_size_cardbus(b, add_head);
break;

case PCI_CLASS_BRIDGE_PCI:
--
1.7.4.1

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