[PATCH 03/12] PCI: Claim hw/fw allocated resources in hot add path.

From: Yinghai Lu
Date: Tue Mar 13 2012 - 03:27:33 EST


During testing remove/rescan root bus 00, found
[ 338.142574] bus: 'pci': really_probe: probing driver ata_piix with device 0000:00:01.1
[ 338.146788] ata_piix 0000:00:01.1: device not available (can't reserve [io 0x01f0-0x01f7])
[ 338.150565] ata_piix: probe of 0000:00:01.1 failed with error -22

because that fixed resource is not claimed from
arch/x86/pci/i386.c::pcibios_allocate_resources()
that is init path.

Try to claim those resources, so on the remove/rescan will still use old
resources.

It is some kind honoring HW/FW setting in the registers during hot add.
esp root-bus hot add is through acpi, BIOS have chance to set some register
for us.

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
arch/x86/pci/i386.c | 10 ++++++++++
drivers/pci/bus.c | 2 ++
drivers/pci/setup-bus.c | 4 ++++
include/linux/pci.h | 1 +
4 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
index 111bcef..3e1dd0e 100644
--- a/arch/x86/pci/i386.c
+++ b/arch/x86/pci/i386.c
@@ -325,6 +325,16 @@ static int __init pcibios_assign_resources(void)
return 0;
}

+void pcibios_resource_survey_bus(struct pci_bus *bus)
+{
+ dev_printk(KERN_DEBUG, &bus->dev, "Allocating resources\n");
+
+ pcibios_allocate_bus_resources(bus);
+
+ pcibios_allocate_resources(bus, 0);
+ pcibios_allocate_resources(bus, 1);
+}
+
void __init pcibios_resource_survey(void)
{
struct pci_bus *bus;
diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index 1eb7944..672ffc8 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -94,6 +94,8 @@ void pci_bus_remove_resources(struct pci_bus *bus)
pci_free_resource_list(&bus->resources);
}

+void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
+
/**
* pci_bus_alloc_resource - allocate a resource from a parent bus
* @bus: PCI bus
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index d9a5500..33f0fcd 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1444,6 +1444,8 @@ void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
IORESOURCE_PREFETCH;

+ pcibios_resource_survey_bus(parent);
+
again:
__pci_bus_size_bridges(parent, &add_list, true);
__pci_bridge_assign_resources(bridge, &add_list, &fail_head);
@@ -1499,6 +1501,8 @@ void pci_assign_unassigned_bus_resources(struct pci_bus *bus)
LIST_HEAD(add_list); /* list of resources that
want additional resources */

+ pcibios_resource_survey_bus(bus);
+
down_read(&pci_bus_sem);
__pci_bus_size_bridges(bus, &add_list, false);
up_read(&pci_bus_sem);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index ec8c4cf..161f6c0 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -643,6 +643,7 @@ extern struct list_head pci_root_buses; /* list of all known PCI buses */
/* Some device drivers need know if pci is initiated */
extern int no_pci_devices(void);

+void pcibios_resource_survey_bus(struct pci_bus *bus);
void pcibios_fixup_bus(struct pci_bus *);
int __must_check pcibios_enable_device(struct pci_dev *, int mask);
char *pcibios_setup(char *str);
--
1.7.7

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