On Fri, Mar 15, 2019 at 02:29:40PM -0500, Alexandru Gagniuc wrote: > _OSC now has a way to inform firmware that OS has the capability to > interpret HPX type 3 tables. Since ACPI 6.3 deprecated _OSC specifics, > these are now part of the PCI Firmware Specification. > > The following is the document describing the changes: > ECN: _HPX and PCIe Completion Timeout related _OSC Enhancements > Date: September 12, 2018 > Affected Document: PCI Firmware Specification, Rev. 3.2 > > Signed-off-by: Alexandru Gagniuc <mr.nuke.me@xxxxxxxxx> Applied to pci/hotplug for v5.2, thanks! > --- > > This patch is designed to go on top of the following series > "PCI: ACPI: Implement support for _HPX Type 3 tables" > https://lkml.org/lkml/2019/3/7/790 > > Although the patch can technically be applied independently, it > doesn't make sense without the rest of the series. > > The HPX3 capability bit, to my understanding, is designed to be > informational. i.e. Setting or not setting it would not affect whether > firmware would export HPX3 tables. It may have implications in FFS > systems, where FW might need to make sure things like the completion > timeout value is set correctly throughout the tree. > > My understanding is that firmware will prefer to set these with HPX3, > in lieu of firing up SMM on hotplug and other events. Firmware can use > the HPX3 support bit to know how to proceed. > > drivers/acpi/pci_root.c | 2 ++ > include/linux/acpi.h | 3 ++- > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c > index 707aafc7c2aa..0bee23893297 100644 > --- a/drivers/acpi/pci_root.c > +++ b/drivers/acpi/pci_root.c > @@ -145,6 +145,7 @@ static struct pci_osc_bit_struct pci_osc_support_bit[] = { > { OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" }, > { OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" }, > { OSC_PCI_MSI_SUPPORT, "MSI" }, > + { OSC_PCI_HPX_TYPE_3_SUPPORT, "HPX-type3" }, > }; > > static struct pci_osc_bit_struct pci_osc_control_bit[] = { > @@ -446,6 +447,7 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm, > * PCI domains, so we indicate this in _OSC support capabilities. > */ > support = OSC_PCI_SEGMENT_GROUPS_SUPPORT; > + support |= OSC_PCI_HPX_TYPE_3_SUPPORT; > if (pci_ext_cfg_avail()) > support |= OSC_PCI_EXT_CONFIG_SUPPORT; > if (pcie_aspm_support_enabled()) > diff --git a/include/linux/acpi.h b/include/linux/acpi.h > index 87715f20b69a..028c138b9082 100644 > --- a/include/linux/acpi.h > +++ b/include/linux/acpi.h > @@ -508,7 +508,8 @@ extern bool osc_pc_lpi_support_confirmed; > #define OSC_PCI_CLOCK_PM_SUPPORT 0x00000004 > #define OSC_PCI_SEGMENT_GROUPS_SUPPORT 0x00000008 > #define OSC_PCI_MSI_SUPPORT 0x00000010 > -#define OSC_PCI_SUPPORT_MASKS 0x0000001f > +#define OSC_PCI_HPX_TYPE_3_SUPPORT 0x00000100 > +#define OSC_PCI_SUPPORT_MASKS 0x0000011f > > /* PCI Host Bridge _OSC: Capabilities DWORD 3: Control Field */ > #define OSC_PCI_EXPRESS_NATIVE_HP_CONTROL 0x00000001 > -- > 2.19.2 >
