Re: [PATCH 1/8] ACPI / PCI: Introduce acpi_pci_osc_control_query()
From: Rafael J. Wysocki <hidden>
Date: 2010-08-03 20:58:40
On Tuesday, August 03, 2010, Rafael J. Wysocki wrote:
On Tuesday, August 03, 2010, Kenji Kaneshige wrote:quoted
(2010/08/03 6:53), Rafael J. Wysocki wrote:quoted
From: Rafael J. Wysocki<redacted><snip.>quoted
+ mutex_lock(&osc_lock); + status = acpi_pci_query_osc(root, root->osc_support_set, ctrl_mask); + mutex_unlock(&osc_lock); +One more comment here. I think we can skip acpi_pci_query_osc() if all of queried controls are already granted to OS. Please see below mutex_lock(&osc_lock); if ((root->osc_control_set & *ctrl_mask) == *ctrl_mask) { *ctrl_mask = root->osc_control_set; goto out; } status = acpi_pci_query_osc(root, root->osc_support_set, ctrl_mask); mutex_unlock(&osc_lock); out:Well I guess you mean: mutex_lock(&osc_lock); if ((root->osc_control_set & *ctrl_mask) != *ctrl_mask) status = acpi_pci_query_osc(root, root->osc_support_set, ctrl_mask); mutex_unlock(&osc_lock); Otherwise we would return with the mutex held. :-)
Updated patch is appended, please tell me what you think. Rafael --- From: Rafael J. Wysocki <redacted> Subject: ACPI / PCI: Introduce acpi_pci_osc_control_query() (v2) 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 <redacted> --- drivers/acpi/pci_root.c | 61 ++++++++++++++++++++++++++++++++++++++++-------- include/linux/acpi.h | 1 2 files changed, 53 insertions(+), 9 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@@ -225,21 +225,32 @@ 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, result, capbuf[3]; + u32 result, 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 | root->osc_control_set; + } else { + /* Run _OSC query for all possible controls. */ + capbuf[OSC_CONTROL_TYPE] = OSC_PCI_CONTROL_MASKS; + } status = acpi_pci_run_osc(root->device->handle, capbuf, &result); if (ACPI_SUCCESS(status)) { - root->osc_support_set = support_set; + root->osc_support_set = support; root->osc_control_qry = result; + if (control) + *control = result; root->osc_queried = 1; } return status;
@@ -254,7 +265,7 @@ 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; }
@@ -363,6 +374,38 @@ out: } EXPORT_SYMBOL_GPL(acpi_get_pci_dev); + /** + * acpi_pci_osc_control_query - Get the _OSC bits the kernel can control. + * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex). + * @mask: Mask of _OSC bits to query and the place to put the result into. + **/ +acpi_status acpi_pci_osc_control_query(acpi_handle handle, u32 *mask) +{ + struct acpi_pci_root *root; + acpi_handle tmp; + acpi_status status = AE_OK; + + if (!mask || !(*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); + if ((*mask & root->osc_control_set) == *mask) + *mask = root->osc_control_set; + else + status = acpi_pci_query_osc(root, root->osc_support_set, 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
@@ -396,7 +439,7 @@ 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_osc_control_query(acpi_handle handle, u32 *mask); extern acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags); extern void acpi_early_init(void);