pcmcia: do not autoadd root PCI bus resources
On the PCI root bus on the x86 architecture, the risk of hitting some strange system devices is too high: If a driver isn't loaded, the resources are not claimed; even if a driver is loaded, it may not request all resources or even the wrong one. We can neither trust the rest of the kernel nor ACPI/PNP and CRS parsing to get it right. Therefore, explicitly spell out what safeguards we provide, and add a safeguard to only use resources which are set up exclusively for the secondary PCI bus (non-subtractive mode): the risk of hitting system devices is quite low, as they usually aren't connected to the secondary PCI bus. CC: Jesse Barnes <jbarnes@virtuousgeek.org> CC: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
This commit is contained in:
parent
b19a7275de
commit
cf26e8dc41
|
@ -935,23 +935,42 @@ static int nonstatic_autoadd_resources(struct pcmcia_socket *s)
|
|||
return -ENODEV;
|
||||
|
||||
#if defined(CONFIG_X86)
|
||||
/* If this is the root bus, the risk of hitting
|
||||
* some strange system devices which aren't protected
|
||||
* by either ACPI resource tables or properly requested
|
||||
* resources is too big. Therefore, don't do auto-adding
|
||||
* of resources at the moment.
|
||||
/* If this is the root bus, the risk of hitting some strange
|
||||
* system devices is too high: If a driver isn't loaded, the
|
||||
* resources are not claimed; even if a driver is loaded, it
|
||||
* may not request all resources or even the wrong one. We
|
||||
* can neither trust the rest of the kernel nor ACPI/PNP and
|
||||
* CRS parsing to get it right. Therefore, use several
|
||||
* safeguards:
|
||||
*
|
||||
* - Do not auto-add resources if the CardBus bridge is on
|
||||
* the PCI root bus
|
||||
*
|
||||
* - Avoid any I/O ports < 0x100.
|
||||
*
|
||||
* - On PCI-PCI bridges, only use resources which are set up
|
||||
* exclusively for the secondary PCI bus: the risk of hitting
|
||||
* system devices is quite low, as they usually aren't
|
||||
* connected to the secondary PCI bus.
|
||||
*/
|
||||
if (s->cb_dev->bus->number == 0)
|
||||
return -EINVAL;
|
||||
#endif
|
||||
|
||||
for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) {
|
||||
res = s->cb_dev->bus->resource[i];
|
||||
#else
|
||||
pci_bus_for_each_resource(s->cb_dev->bus, res, i) {
|
||||
#endif
|
||||
if (!res)
|
||||
continue;
|
||||
|
||||
if (res->flags & IORESOURCE_IO) {
|
||||
/* safeguard against the root resource, where the
|
||||
* risk of hitting any other device would be too
|
||||
* high */
|
||||
if (res == &ioport_resource)
|
||||
continue;
|
||||
|
||||
dev_printk(KERN_INFO, &s->cb_dev->dev,
|
||||
"pcmcia: parent PCI bridge window: %pR\n",
|
||||
res);
|
||||
|
@ -961,8 +980,12 @@ static int nonstatic_autoadd_resources(struct pcmcia_socket *s)
|
|||
}
|
||||
|
||||
if (res->flags & IORESOURCE_MEM) {
|
||||
/* safeguard against the root resource, where the
|
||||
* risk of hitting any other device would be too
|
||||
* high */
|
||||
if (res == &iomem_resource)
|
||||
continue;
|
||||
|
||||
dev_printk(KERN_INFO, &s->cb_dev->dev,
|
||||
"pcmcia: parent PCI bridge window: %pR\n",
|
||||
res);
|
||||
|
|
Loading…
Reference in New Issue