hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

PCI / ACPI fix for v4.1-rc6 

This fixes a bug uncovered by a recent driver core change that
 modified the implementation of the ACPI_COMPANION_SET() macro to
 strictly rely on its second argument to be either NULL or a valid
 pointer to struct acpi_device.
 
 As it turns out, pcibios_root_bridge_prepare() on x86 and ia64
 works with the assumption that the only code path calling
 pci_create_root_bus() is pci_acpi_scan_root() and therefore
 the sysdata argument passed to it will always match the
 expectations of pcibios_root_bridge_prepare().  That need not
 be the case, however, and in particular it is not the case for
 the Xen pcifront driver that passes a pointer to its own private
 data strcture as sysdata to pci_scan_bus_parented() which then
 passes it to pci_create_root_bus() and it ends up being used
 incorrectly by pcibios_root_bridge_prepare().
 
 /
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIcBAABCAAGBQJVaP1HAAoJEILEb/54YlRxpwEQAJn+6phfcLZiBkwRCvGAmWwv
 Hi5UhcLCZb8r0RX+CssrwDxmiTD+OO5Kume7yqzb9R1EJfEWcx7dOnvrtl6mfy9E
 sfWuU/ILF9TW57bqEHBde921VwtRh3BQ4fOCbp4qYEEXjFx+N/UOYHRefgWzvgYP
 0j9U7HvwBatIjOC6gPWDyoOI7AYZwBVh4lhjYTPfOTta7QqbjFPD1b+EaAqSyNsl
 TqrTQDgtxMTL02u50fP1hLJtOibdp7gOTRlEyfCJru4JjHBTRxBlaefymGi4e2Nw
 5bFyXlDv4SVAGpE2XFDIJftAkAs+lXPjfIt7aHPB+DSa01axBesyqLITQV9wDoL8
 AETnGomgoe+fsymJ1Pk4JOar6bKJmezAwDibi7bDcUoZkTD91VREwZiaLR+kEvzH
 msujMNV0SdVS+PIZUNIwYE6t/ffSDnHjdGjGnsAhNt2JtFFcDKyNkf21O4NYlV99
 iLLx/YY+kxmTBuV+L9pjEefS/u9g60cdjslPFBzffXIZ8N9g2uKOqB6ulfg2dSm/
 tB5u8gyTuR++jmm/f+rlpCCzQ4EMG9ciZnZJfce3m961Sac2kNacGARMMIAe6xMq
 ijuOgcVZZibGBviG5v64ntTQki9qgmImZiPCSoOn+3UgrkCExJfUNDSVl5tQA6MP
 oJEj4WRvH2LrFd/PjPlW
 =ulKW
 -----END PGP SIGNATURE-----

Merge tag 'acpi-pci-4.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull PCI / ACPI fix from Rafael Wysocki:
 "This fixes a bug uncovered by a recent driver core change that
  modified the implementation of the ACPI_COMPANION_SET() macro to
  strictly rely on its second argument to be either NULL or a valid
  pointer to struct acpi_device.

  As it turns out, pcibios_root_bridge_prepare() on x86 and ia64 works
  with the assumption that the only code path calling pci_create_root_bus()
  is pci_acpi_scan_root() and therefore the sysdata argument passed to
  it will always match the expectations of pcibios_root_bridge_prepare().

  That need not be the case, however, and in particular it is not the
  case for the Xen pcifront driver that passes a pointer to its own
  private data strcture as sysdata to pci_scan_bus_parented() which then
  passes it to pci_create_root_bus() and it ends up being used incorrectly
  by pcibios_root_bridge_prepare()"

* tag 'acpi-pci-4.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PCI / ACPI: Do not set ACPI companions for host bridges with parents
This commit is contained in:
Linus Torvalds 2015-05-29 17:09:39 -07:00
parent 1be44e234b dc4fdaf0e4
commit aaa20fc233
2 changed files with 20 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
arch/ia64/pci/pci.c
View File

@ -478,9 +478,16 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge) int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
{ {
/*
* We pass NULL as parent to pci_create_root_bus(), so if it is not NULL
* here, pci_create_root_bus() has been called by someone else and
* sysdata is likely to be different from what we expect. Let it go in
* that case.
*/
if (!bridge->dev.parent) {
struct pci_controller *controller = bridge->bus->sysdata; struct pci_controller *controller = bridge->bus->sysdata;
ACPI_COMPANION_SET(&bridge->dev, controller->companion); ACPI_COMPANION_SET(&bridge->dev, controller->companion);
}
return 0; return 0;
} }

9
arch/x86/pci/acpi.c
View File

@ -482,9 +482,16 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge) int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
{ {
/*
* We pass NULL as parent to pci_create_root_bus(), so if it is not NULL
* here, pci_create_root_bus() has been called by someone else and
* sysdata is likely to be different from what we expect. Let it go in
* that case.
*/
if (!bridge->dev.parent) {
struct pci_sysdata *sd = bridge->bus->sysdata; struct pci_sysdata *sd = bridge->bus->sysdata;
ACPI_COMPANION_SET(&bridge->dev, sd->companion); ACPI_COMPANION_SET(&bridge->dev, sd->companion);
}
return 0; return 0;
} }