linux/drivers/pci
Bjorn Helgaas d2f54d9b3e PCI: Prevent bus conflicts while checking for bridge apertures
pci_bridge_check_ranges() determines whether the bridge supports an I/O
aperture and a prefetchable memory aperture.

Previously, if the I/O aperture was unsupported, disabled, or configured at
[io 0x0000-0x0fff], we wrote 0xf0 to PCI_IO_BASE and PCI_IO_LIMIT, which,
if the bridge supports it, enables the I/O aperture at [io 0xf000-0xffff].
The enabled aperture may conflict with other devices in the system.

Similarly, we wrote 0xfff0 to PCI_PREF_MEMORY_BASE and
PCI_PREF_MEMORY_LIMIT, which enables the prefetchable memory aperture at
[mem 0xfff00000-0xffffffff], and that may also conflict with other devices.

All we need to know is whether the base and limit registers are writable,
so we can use values that leave the apertures disabled, e.g., PCI_IO_BASE =
0xf0, PCI_IO_LIMIT = 0xe0, PCI_PREF_MEMORY_BASE = 0xfff0,
PCI_PREF_MEMORY_LIMIT = 0xffe0.

Writing non-zero values to both the base and limit registers means we
detect whether either or both are writable, as we did before.

Reported-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Based-on-patch-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-12-13 08:44:30 -07:00
..
host PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
hotplug PCI updates for v3.13: 2013-11-22 10:53:47 -08:00
pcie PCI/portdrv: Remove superfluous name cast 2013-12-13 08:44:29 -07:00
access.c PCI: Remove pcie_cap_has_devctl() 2013-08-28 20:51:39 -06:00
ats.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
bus.c PCI: Delay enabling bridges until they're needed 2013-07-25 12:35:03 -06:00
host-bridge.c
hotplug-pci.c
htirq.c
ioapic.c ACPI: Eliminate the DEVICE_ACPI_HANDLE() macro 2013-11-14 23:17:21 +01:00
iov.c PCI: Clear NumVFs when disabling SR-IOV in sriov_init() 2013-11-22 14:53:27 -07:00
irq.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
Kconfig PCI: remove ARCH_SUPPORTS_MSI kconfig option 2013-08-12 15:26:48 +00:00
Makefile pci: PCIe driver for Marvell Armada 370/XP systems 2013-05-20 19:18:44 +00:00
msi.c PCI: Drop "irq" param from *_restore_msi_irqs() 2013-12-13 08:44:30 -07:00
of.c
pci-acpi.c PCI updates for v3.13: 2013-11-22 10:53:47 -08:00
pci-driver.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
pci-label.c ACPI: Eliminate the DEVICE_ACPI_HANDLE() macro 2013-11-14 23:17:21 +01:00
pci-stub.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
pci-sysfs.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
pci.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
pci.h PCI: convert bus code to use dev_groups 2013-10-07 14:58:42 -06:00
probe.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
proc.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
quirks.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
remove.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
rom.c
search.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
setup-bus.c PCI: Prevent bus conflicts while checking for bridge apertures 2013-12-13 08:44:30 -07:00
setup-irq.c
setup-res.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
slot.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
syscall.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
vpd.c
xen-pcifront.c xen/pcifront: Deal with toolstack missing 'XenbusStateClosing' state. 2013-06-14 12:28:59 -04:00