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path: root/drivers/pci/hotplug/acpi_pcihp.c
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Diffstat (limited to 'drivers/pci/hotplug/acpi_pcihp.c')
-rw-r--r--drivers/pci/hotplug/acpi_pcihp.c85
1 files changed, 81 insertions, 4 deletions
diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c
index f8c187a763bd..93e37f0666ab 100644
--- a/drivers/pci/hotplug/acpi_pcihp.c
+++ b/drivers/pci/hotplug/acpi_pcihp.c
@@ -30,6 +30,7 @@
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.h>
+#include <linux/pci-acpi.h>
#include <acpi/acpi.h>
#include <acpi/acpi_bus.h>
#include <acpi/actypes.h>
@@ -299,7 +300,7 @@ free_and_return:
*
* @handle - the handle of the hotplug controller.
*/
-acpi_status acpi_run_oshp(acpi_handle handle)
+static acpi_status acpi_run_oshp(acpi_handle handle)
{
acpi_status status;
struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
@@ -322,9 +323,6 @@ acpi_status acpi_run_oshp(acpi_handle handle)
kfree(string.pointer);
return status;
}
-EXPORT_SYMBOL_GPL(acpi_run_oshp);
-
-
/* acpi_get_hp_params_from_firmware
*
@@ -374,6 +372,85 @@ acpi_status acpi_get_hp_params_from_firmware(struct pci_bus *bus,
}
EXPORT_SYMBOL_GPL(acpi_get_hp_params_from_firmware);
+/**
+ * acpi_get_hp_hw_control_from_firmware
+ * @dev: the pci_dev of the bridge that has a hotplug controller
+ * @flags: requested control bits for _OSC
+ *
+ * Attempt to take hotplug control from firmware.
+ */
+int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags)
+{
+ acpi_status status;
+ acpi_handle chandle, handle = DEVICE_ACPI_HANDLE(&(dev->dev));
+ struct pci_dev *pdev = dev;
+ struct pci_bus *parent;
+ struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
+
+ flags &= (OSC_PCI_EXPRESS_NATIVE_HP_CONTROL |
+ OSC_SHPC_NATIVE_HP_CONTROL |
+ OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
+ if (!flags) {
+ err("Invalid flags %u specified!\n", flags);
+ return -EINVAL;
+ }
+
+ /*
+ * 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;
+ parent = pdev->bus->parent;
+ dbg("Could not find %s in acpi namespace, trying parent\n",
+ pci_name(pdev));
+ if (!parent->self)
+ /* Parent must be a host bridge */
+ handle = acpi_get_pci_rootbridge_handle(
+ pci_domain_nr(parent),
+ parent->number);
+ else
+ handle = DEVICE_ACPI_HANDLE(&(parent->self->dev));
+ pdev = parent->self;
+ }
+
+ while (handle) {
+ acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
+ dbg("Trying to get hotplug control for %s \n",
+ (char *)string.pointer);
+ status = pci_osc_control_set(handle, flags);
+ 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), (char *)string.pointer);
+ kfree(string.pointer);
+ return 0;
+ }
+ if (acpi_root_bridge(handle))
+ break;
+ chandle = handle;
+ status = acpi_get_parent(chandle, &handle);
+ if (ACPI_FAILURE(status))
+ break;
+ }
+
+ dbg("Cannot get control of hotplug hardware for pci %s\n",
+ pci_name(dev));
+
+ kfree(string.pointer);
+ return -ENODEV;
+}
+EXPORT_SYMBOL(acpi_get_hp_hw_control_from_firmware);
/* acpi_root_bridge - check to see if this acpi object is a root bridge
*