Aaron reported that a 32-bit x86 kernel with Physical Address Extension
(PAE) support complains about bridge prefetchable memory windows above 4GB:
pci_bus 0000:00: root bus resource [mem 0x380000000000-0x383fffffffff]
...
pci 0000:03:00.0: reg 0x10: [mem 0x383fffc00000-0x383fffdfffff 64bit pref]
pci 0000:03:00.0: reg 0x20: [mem 0x383fffe04000-0x383fffe07fff 64bit pref]
pci 0000:03:00.1: reg 0x10: [mem 0x383fffa00000-0x383fffbfffff 64bit pref]
pci 0000:03:00.1: reg 0x20: [mem 0x383fffe00000-0x383fffe03fff 64bit pref]
pci 0000:00:02.2: PCI bridge to [bus 03-04]
pci 0000:00:02.2: bridge window [io 0x1000-0x1fff]
pci 0000:00:02.2: bridge window [mem 0x91900000-0x91cfffff]
pci 0000:00:02.2: can't handle 64-bit address space for bridge
In this kernel, unsigned long is 32 bits and dma_addr_t is 64 bits.
Previously we used "unsigned long" to hold the bridge window address. But
this is a bus address, so we should use dma_addr_t instead.
Use dma_addr_t to hold the bridge window base and limit.
The question of whether the CPU can actually *address* the window is
separate and depends on what the physical address space of the CPU is and
whether the host bridge does any address translation.
[bhelgaas: fix "shift count > width of type", changelog, stable tag]
Fixes: d56dbf5bab8c ("PCI: Allocate 64-bit BARs above 4G when possible")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=88131
Reported-by: Aaron Ma <mapengyu@gmail.com>
Tested-by: Aaron Ma <mapengyu@gmail.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org # v3.14+
7fc986d8a9