[PATCH -v2] PCI: Clear all bridge res MEM_64 if host bridge has non mem64

From: Yinghai Lu
Date: Wed Dec 10 2014 - 19:20:18 EST


So we could use bridge 64bit mem pref for children mem pref instead of
forcing them into bridge mem.

Could help Marek's system as his system is using _CRS, and all mem res is under
4G.

-v2: fix checking logic problem found by Gravin and Wei.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=85491
Reported-by: Marek Kordik <kordikmarek@xxxxxxxxx>
Fixes: 5b28541552ef ("PCI: Restrict 64-bit prefetchable bridge windows to 64-bit resources")
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>

---
drivers/pci/host-bridge.c | 7 +++++++
drivers/pci/pci.h | 1 +
drivers/pci/probe.c | 9 +++++++++
drivers/pci/setup-bus.c | 3 +++
include/linux/pci.h | 1 +
5 files changed, 21 insertions(+)

Index: linux-2.6/drivers/pci/host-bridge.c
===================================================================
--- linux-2.6.orig/drivers/pci/host-bridge.c
+++ linux-2.6/drivers/pci/host-bridge.c
@@ -31,6 +31,13 @@ void pci_set_host_bridge_release(struct
bridge->release_data = release_data;
}

+bool pcibios_host_bridge_has_mem64_res(struct pci_bus *bus)
+{
+ struct pci_host_bridge *bridge = find_pci_host_bridge(bus);
+
+ return bridge->has_mem64_res;
+}
+
void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
struct resource *res)
{
Index: linux-2.6/drivers/pci/pci.h
===================================================================
--- linux-2.6.orig/drivers/pci/pci.h
+++ linux-2.6/drivers/pci/pci.h
@@ -196,6 +196,7 @@ enum pci_bar_type {
pci_bar_mem64, /* A 64-bit memory BAR */
};

+bool pcibios_host_bridge_has_mem64_res(struct pci_bus *bus);
bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl,
int crs_timeout);
int pci_setup_device(struct pci_dev *dev);
Index: linux-2.6/drivers/pci/probe.c
===================================================================
--- linux-2.6.orig/drivers/pci/probe.c
+++ linux-2.6/drivers/pci/probe.c
@@ -1980,6 +1980,15 @@ struct pci_bus *pci_create_root_bus(stru
dev_info(&b->dev, "root bus resource %pR%s\n", res, bus_addr);
}

+ list_for_each_entry(window, &bridge->windows, list) {
+ res = window->res;
+ if (resource_type(res) == IORESOURCE_MEM &&
+ (res->end - window->offset) > 0xffffffff) {
+ bridge->has_mem64_res = true;
+ break;
+ }
+ }
+
down_write(&pci_bus_sem);
list_add_tail(&b->node, &pci_root_buses);
up_write(&pci_bus_sem);
Index: linux-2.6/include/linux/pci.h
===================================================================
--- linux-2.6.orig/include/linux/pci.h
+++ linux-2.6/include/linux/pci.h
@@ -407,6 +407,7 @@ struct pci_host_bridge {
struct list_head windows; /* pci_host_bridge_windows */
void (*release_fn)(struct pci_host_bridge *);
void *release_data;
+ bool has_mem64_res;
};

#define to_pci_host_bridge(n) container_of(n, struct pci_host_bridge, dev)
Index: linux-2.6/drivers/pci/setup-bus.c
===================================================================
--- linux-2.6.orig/drivers/pci/setup-bus.c
+++ linux-2.6/drivers/pci/setup-bus.c
@@ -693,6 +693,9 @@ static void pci_bridge_check_ranges(stru
}
}

+ if (!pcibios_host_bridge_has_mem64_res(bus))
+ b_res[2].flags &= ~IORESOURCE_MEM_64;
+
/* double check if bridge does support 64 bit pref */
if (b_res[2].flags & IORESOURCE_MEM_64) {
u32 mem_base_hi, tmp;
--
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