/* pci_get_hp_params
*
* @dev - the pci_dev for which we want parameters
* @hpp - allocated by the caller
*/
int pci_get_hp_params(struct pci_dev *dev, struct hotplug_params *hpp)
{
acpi_status status;
acpi_handle handle, phandle;
struct pci_bus *pbus;
handle = NULL;
for (pbus = dev->bus; pbus; pbus = pbus->parent) {
handle = acpi_pci_get_bridge_handle(pbus);
if (handle)
break;
}
/*
* _HPP settings apply to all child buses, until another _HPP is
* encountered. If we don't find an _HPP for the input pci dev,
* look for it in the parent device scope since that would apply to
* this pci dev.
*/
while (handle) {
status = acpi_run_hpx(handle, hpp);
if (ACPI_SUCCESS(status))
return 0;
status = acpi_run_hpp(handle, hpp);
if (ACPI_SUCCESS(status))
return 0;
if (acpi_is_root_bridge(handle))
break;
status = acpi_get_parent(handle, &phandle);
if (ACPI_FAILURE(status))
break;
handle = phandle;
}
return -ENODEV;
}
/**
* acpi_pcihp_check_ejectable - check if handle is ejectable ACPI PCI slot
* @pbus: the PCI bus of the PCI slot corresponding to 'handle'
* @handle: ACPI handle to check
*
* Return 1 if handle is ejectable PCI slot, 0 otherwise.
*/
int acpi_pci_check_ejectable(struct pci_bus *pbus, acpi_handle handle)
{
acpi_handle bridge_handle, parent_handle;
bridge_handle = acpi_pci_get_bridge_handle(pbus);
if (!bridge_handle)
return 0;
if ((ACPI_FAILURE(acpi_get_parent(handle, &parent_handle))))
return 0;
if (bridge_handle != parent_handle)
return 0;
return pcihp_is_ejectable(handle);
}
/**
* acpi_get_hp_hw_control_from_firmware
* @dev: the pci_dev of the bridge that has a hotplug controller
*
* Attempt to take hotplug control from firmware.
*/
int acpi_get_hp_hw_control_from_firmware(struct pci_dev *pdev)
{
const struct pci_host_bridge *host;
const struct acpi_pci_root *root;
acpi_status status;
acpi_handle chandle, handle;
struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
/*
* If there's no ACPI host bridge (i.e., ACPI support is compiled
* into the kernel but the hardware platform doesn't support ACPI),
* there's nothing to do here.
*/
host = pci_find_host_bridge(pdev->bus);
root = acpi_pci_find_root(ACPI_HANDLE(&host->dev));
if (!root)
return 0;
/*
* If _OSC exists, it determines whether we're allowed to manage
* the SHPC. We executed it while enumerating the host bridge.
*/
if (root->osc_support_set) {
if (host->native_shpc_hotplug)
return 0;
return -ENODEV;
}
/*
* In the absence of _OSC, we're always allowed to manage the SHPC.
* However, if an OSHP method is present, we must execute it so the
* firmware can transfer control to the OS, e.g., direct interrupts
* to the OS instead of to the firmware.
*
* N.B. The PCI Firmware Spec (r3.2, sec 4.8) does not endorse
* searching up the ACPI hierarchy, so the loops below are suspect.
*/
handle = ACPI_HANDLE(&pdev->dev);
if (!handle) {
/*
* This hotplug controller was not listed in the ACPI name
* space at all. Try to get ACPI handle of parent PCI bus.
*/
struct pci_bus *pbus;
for (pbus = pdev->bus; pbus; pbus = pbus->parent) {
handle = acpi_pci_get_bridge_handle(pbus);
if (handle)
break;
}
}
while (handle) {
acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
pci_info(pdev, "Requesting control of SHPC hotplug via OSHP (%s)\n",
(char *)string.pointer);
status = acpi_run_oshp(handle);
if (ACPI_SUCCESS(status))
goto got_one;
if (acpi_is_root_bridge(handle))
break;
chandle = handle;
status = acpi_get_parent(chandle, &handle);
if (ACPI_FAILURE(status))
break;
}
pci_info(pdev, "Cannot get control of SHPC hotplug\n");
kfree(string.pointer);
return -ENODEV;
got_one:
pci_info(pdev, "Gained control of SHPC hotplug (%s)\n",
(char *)string.pointer);
kfree(string.pointer);
return 0;
}
