int pciehp_get_hp_hw_control_from_firmware(struct pci_dev *dev)
{
acpi_status status;
acpi_handle chandle, handle = DEVICE_ACPI_HANDLE(&(dev->dev));
struct pci_dev *pdev = dev;
u8 *path_name;
/*
* Per PCI firmware specification, we should run the ACPI _OSC
* method to get control of hotplug hardware before using it.
* If an _OSC is missing, we look for an OSHP to do the same thing.
* To handle different BIOS behavior, we look for _OSC and OSHP
* within the scope of the hotplug controller and its parents, upto
* the host bridge under which this controller exists.
*/
while (!handle) {
/*
* This hotplug controller was not listed in the ACPI name
* space at all. Try to get acpi handle of parent pci bus.
*/
if (!pdev || !pdev->bus->parent)
break;
dbg("Could not find %s in acpi namespace, trying parent\n",
pci_name(pdev));
if (!pdev->bus->parent->self)
/* Parent must be a host bridge */
handle = acpi_get_pci_rootbridge_handle(
pci_domain_nr(pdev->bus->parent),
pdev->bus->parent->number);
else
handle = DEVICE_ACPI_HANDLE(
&(pdev->bus->parent->self->dev));
pdev = pdev->bus->parent->self;
}
while (handle) {
path_name = acpi_path_name(handle);
dbg("Trying to get hotplug control for %s \n", path_name);
status = pci_osc_control_set(handle,
OSC_PCI_EXPRESS_NATIVE_HP_CONTROL);
if (status == AE_NOT_FOUND)
status = acpi_run_oshp(handle);
if (ACPI_SUCCESS(status)) {
dbg("Gained control for hotplug HW for pci %s (%s)\n",
pci_name(dev), path_name);
return 0;
}
if (is_root_bridge(handle))
break;
chandle = handle;
status = acpi_get_parent(chandle, &handle);
if (ACPI_FAILURE(status))
break;
}
err("Cannot get control of hotplug hardware for pci %s\n",
pci_name(dev));
return -1;
}
void get_hp_hw_control_from_firmware(struct pci_dev *dev)
{
/*
* OSHP is an optional ACPI firmware control method. If present,
* we need to run it to inform BIOS that we will control SHPC
* hardware from now on.
*/
acpi_handle handle = DEVICE_ACPI_HANDLE(&(dev->dev));
if (!handle)
return;
acpi_run_oshp(handle);
}
static int acpi_add_slot_to_php_slots(
struct acpi_bridge *ab,
int bus_num,
acpi_handle handle,
u32 adr,
u32 sun
)
{
struct acpi_php_slot *aps;
static long samesun = -1;
aps = (struct acpi_php_slot *) kmalloc (sizeof(struct acpi_php_slot), GFP_KERNEL);
if (!aps) {
err ("acpi_shpchprm: alloc for aps fail\n");
return -1;
}
memset(aps, 0, sizeof(struct acpi_php_slot));
aps->handle = handle;
aps->bus = bus_num;
aps->dev = (adr >> 16) & 0xffff;
aps->fun = adr & 0xffff;
aps->sun = sun;
aps->next = ab->slots; /* cling to the bridge */
aps->bridge = ab;
ab->slots = aps;
ab->scanned += 1;
if (!ab->_hpp)
acpi_get__hpp(ab);
acpi_run_oshp(ab);
if (sun != samesun) {
info("acpi_shpchprm: Slot sun(%x) at s:b:d:f=0x%02x:%02x:%02x:%02x\n", aps->sun, ab->seg,
aps->bus, aps->dev, aps->fun);
samesun = sun;
}
return 0;
}
/**
* 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;
}
