(2010/07/31 7:26), Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rjw@xxxxxxx>
>
> Introduce a function allowing the caller to obtain a mask of _OSC
> control bits the BIOS will allow the kernel to control for a given
> PCI root bridge.
>
> Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
> ---
> drivers/acpi/pci_root.c | 56 +++++++++++++++++++++++++++++++++++++++++-------
> include/linux/acpi.h | 1
> 2 files changed, 49 insertions(+), 8 deletions(-)
>
> Index: linux-2.6/drivers/acpi/pci_root.c
> ===================================================================
> --- linux-2.6.orig/drivers/acpi/pci_root.c
> +++ linux-2.6/drivers/acpi/pci_root.c
> @@ -224,21 +224,32 @@ static acpi_status acpi_pci_run_osc(acpi
> return status;
> }
>
> -static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, u32 flags)
> +static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
> + u32 support,
> + u32 *control)
> {
> acpi_status status;
> - u32 support_set, capbuf[3];
> + u32 capbuf[3];
> +
> + support &= OSC_PCI_SUPPORT_MASKS;
> + support |= root->osc_support_set;
>
> /* do _OSC query for all possible controls */
> - support_set = root->osc_support_set | (flags & OSC_PCI_SUPPORT_MASKS);
> capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
> - capbuf[OSC_SUPPORT_TYPE] = support_set;
> - capbuf[OSC_CONTROL_TYPE] = OSC_PCI_CONTROL_MASKS;
> + capbuf[OSC_SUPPORT_TYPE] = support;
> + if (control) {
> + *control &= OSC_PCI_CONTROL_MASKS;
> + capbuf[OSC_CONTROL_TYPE] = *control;
> + } else {
> + capbuf[OSC_CONTROL_TYPE] = OSC_PCI_CONTROL_MASKS;
> + }
>
> status = acpi_pci_run_osc(root->device->handle, capbuf);
> if (ACPI_SUCCESS(status)) {
> - root->osc_support_set = support_set;
> + root->osc_support_set = support;
> root->osc_control_qry = capbuf[OSC_CONTROL_TYPE];
> + if (control)
> + *control = capbuf[OSC_CONTROL_TYPE];
> root->osc_queried = 1;
> }
> return status;
> @@ -253,7 +264,7 @@ static acpi_status acpi_pci_osc_support(
> if (ACPI_FAILURE(status))
> return status;
> mutex_lock(&osc_lock);
> - status = acpi_pci_query_osc(root, flags);
> + status = acpi_pci_query_osc(root, flags, NULL);
> mutex_unlock(&osc_lock);
> return status;
> }
> @@ -362,6 +373,35 @@ out:
> }
> EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
>
> + /**
> + * acpi_pci_root_osc_query - Get the _OSC bits the kernel can control.
> + * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
> + * @ctrl_mask: Mask of _OSC bits to query and the place to put the result into.
> + **/
> +acpi_status acpi_pci_root_osc_query(acpi_handle handle, u32 *ctrl_mask)
> +{
> + acpi_status status;
> + acpi_handle tmp;
> + struct acpi_pci_root *root;
> +
> + if (!ctrl_mask || !(*ctrl_mask & OSC_PCI_CONTROL_MASKS))
> + return AE_BAD_PARAMETER;
> +
> + root = acpi_pci_find_root(handle);
> + if (!root)
> + return AE_NOT_EXIST;
> +
> + status = acpi_get_handle(handle, "_OSC", &tmp);
> + if (ACPI_FAILURE(status))
> + return status;
> +
> + mutex_lock(&osc_lock);
> + status = acpi_pci_query_osc(root, root->osc_support_set, ctrl_mask);
> + mutex_unlock(&osc_lock);
> +
> + return status;
> +}
> +
> /**
> * acpi_pci_osc_control_set - commit requested control to Firmware
> * @handle: acpi_handle for the target ACPI object
> @@ -395,7 +435,7 @@ acpi_status acpi_pci_osc_control_set(acp
>
> /* Need to query controls first before requesting them */
> if (!root->osc_queried) {
> - status = acpi_pci_query_osc(root, root->osc_support_set);
> + status = acpi_pci_query_osc(root, root->osc_support_set, NULL);
> if (ACPI_FAILURE(status))
> goto out;
> }
> Index: linux-2.6/include/linux/acpi.h
> ===================================================================
> --- linux-2.6.orig/include/linux/acpi.h
> +++ linux-2.6/include/linux/acpi.h
> @@ -305,6 +305,7 @@ acpi_status acpi_run_osc(acpi_handle han
> OSC_PCI_EXPRESS_AER_CONTROL | \
> OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL)
>
> +extern acpi_status acpi_pci_root_osc_query(acpi_handle handle, u32 *ctrl_mask);
> extern acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags);
> extern void acpi_early_init(void);
IMHO acpi_pci_osc_control_query() is better name for new function here,
to make it be paired with acpi_pci_osc_control_set(), and to avoid mistakable
"*_get" that sounds like it takes controls via _OSC.
Thanks,
H.Seto
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