[PATCH v2 1/2] PCI/APCI: Move acpi_pci_osc_support() check to negotiation phase
From: Joerg Roedel
Date: Wed Jul 14 2021 - 04:55:31 EST
From: Joerg Roedel <jroedel@xxxxxxx>
The acpi_pci_osc_support() does an _OSC query with _OSC supported set
to what the OS supports but a zero _OSC control value, only to later
claim the features Linux wants to control with an extra _OSC query.
Nothing between the two _OSC querys depends on the result of the first
one (if successfull), and if the supported query fails the control
query will fail too. So it is a good code simplification to combine
these two querys into one.
As a result the acpi_pci_osc_support() function can be removed and
acpi_pci_query_osc() be simplified because it no longer called with a
NULL pointer for *control. Also some code duplication in the existing
error paths was consolidated.
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
---
drivers/acpi/pci_root.c | 114 ++++++++++++++++++----------------------
1 file changed, 52 insertions(+), 62 deletions(-)
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index d7deedf3548e..c703832b7f7f 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -201,31 +201,20 @@ static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
support &= OSC_PCI_SUPPORT_MASKS;
support |= root->osc_support_set;
+ *control &= OSC_PCI_CONTROL_MASKS;
capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
capbuf[OSC_SUPPORT_DWORD] = support;
- if (control) {
- *control &= OSC_PCI_CONTROL_MASKS;
- capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
- } else {
- /* Run _OSC query only with existing controls. */
- capbuf[OSC_CONTROL_DWORD] = root->osc_control_set;
- }
+ capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
if (ACPI_SUCCESS(status)) {
root->osc_support_set = support;
- if (control)
- *control = result;
+ *control = result;
}
return status;
}
-static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
-{
- return acpi_pci_query_osc(root, flags, NULL);
-}
-
struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
{
struct acpi_pci_root *root;
@@ -348,7 +337,8 @@ EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
* _OSC bits the BIOS has granted control of, but its contents are meaningless
* on failure.
**/
-static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
+static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32
+ *mask, u32 req, u32 support)
{
struct acpi_pci_root *root;
acpi_status status;
@@ -372,7 +362,7 @@ static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 r
/* Need to check the available controls bits before requesting them. */
while (*mask) {
- status = acpi_pci_query_osc(root, root->osc_support_set, mask);
+ status = acpi_pci_query_osc(root, support, mask);
if (ACPI_FAILURE(status))
return status;
if (ctrl == *mask)
@@ -402,7 +392,7 @@ static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 r
static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
bool is_pcie)
{
- u32 support, control, requested;
+ u32 support, control = 0, requested;
acpi_status status;
struct acpi_device *device = root->device;
acpi_handle handle = device->handle;
@@ -435,59 +425,49 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
support |= OSC_PCI_EDR_SUPPORT;
decode_osc_support(root, "OS supports", support);
- status = acpi_pci_osc_support(root, support);
- if (ACPI_FAILURE(status)) {
- *no_aspm = 1;
- /* _OSC is optional for PCI host bridges */
- if ((status == AE_NOT_FOUND) && !is_pcie)
+ if (!pcie_ports_disabled) {
+ if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
+ decode_osc_support(root, "not requesting OS control; OS requires",
+ ACPI_PCIE_REQ_SUPPORT);
return;
+ }
- dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n",
- acpi_format_exception(status));
- return;
- }
-
- if (pcie_ports_disabled) {
- dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
- return;
- }
-
- if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
- decode_osc_support(root, "not requesting OS control; OS requires",
- ACPI_PCIE_REQ_SUPPORT);
- return;
- }
-
- control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
- | OSC_PCI_EXPRESS_PME_CONTROL;
+ control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
+ | OSC_PCI_EXPRESS_PME_CONTROL;
- if (IS_ENABLED(CONFIG_PCIEASPM))
- control |= OSC_PCI_EXPRESS_LTR_CONTROL;
+ if (IS_ENABLED(CONFIG_PCIEASPM))
+ control |= OSC_PCI_EXPRESS_LTR_CONTROL;
- if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
- control |= OSC_PCI_EXPRESS_NATIVE_HP_CONTROL;
+ if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
+ control |= OSC_PCI_EXPRESS_NATIVE_HP_CONTROL;
- if (IS_ENABLED(CONFIG_HOTPLUG_PCI_SHPC))
- control |= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
+ if (IS_ENABLED(CONFIG_HOTPLUG_PCI_SHPC))
+ control |= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
- if (pci_aer_available())
- control |= OSC_PCI_EXPRESS_AER_CONTROL;
+ if (pci_aer_available())
+ control |= OSC_PCI_EXPRESS_AER_CONTROL;
- /*
- * Per the Downstream Port Containment Related Enhancements ECN to
- * the PCI Firmware Spec, r3.2, sec 4.5.1, table 4-5,
- * OSC_PCI_EXPRESS_DPC_CONTROL indicates the OS supports both DPC
- * and EDR.
- */
- if (IS_ENABLED(CONFIG_PCIE_DPC) && IS_ENABLED(CONFIG_PCIE_EDR))
- control |= OSC_PCI_EXPRESS_DPC_CONTROL;
+ /*
+ * Per the Downstream Port Containment Related Enhancements ECN to
+ * the PCI Firmware Spec, r3.2, sec 4.5.1, table 4-5,
+ * OSC_PCI_EXPRESS_DPC_CONTROL indicates the OS supports both DPC
+ * and EDR.
+ */
+ if (IS_ENABLED(CONFIG_PCIE_DPC) && IS_ENABLED(CONFIG_PCIE_EDR))
+ control |= OSC_PCI_EXPRESS_DPC_CONTROL;
+ }
+ /* Need an _OSC call even with pcie_ports_disabled set */
requested = control;
status = acpi_pci_osc_control_set(handle, &control,
- OSC_PCI_EXPRESS_CAPABILITY_CONTROL);
+ OSC_PCI_EXPRESS_CAPABILITY_CONTROL,
+ support);
+
if (ACPI_SUCCESS(status)) {
- decode_osc_control(root, "OS now controls", control);
+ if (control)
+ decode_osc_control(root, "OS now controls", control);
+
if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
/*
* We have ASPM control, but the FADT indicates that
@@ -498,10 +478,8 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
*no_aspm = 1;
}
} else {
- decode_osc_control(root, "OS requested", requested);
- decode_osc_control(root, "platform willing to grant", control);
- dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n",
- acpi_format_exception(status));
+ /* Platform wants to control PCIe features */
+ root->osc_support_set = 0;
/*
* We want to disable ASPM here, but aspm_disabled
@@ -511,6 +489,18 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
* root scan.
*/
*no_aspm = 1;
+
+ /* _OSC is optional for PCI host bridges */
+ if ((status == AE_NOT_FOUND) && !is_pcie)
+ return;
+
+ if (requested) {
+ decode_osc_control(root, "OS requested", requested);
+ decode_osc_control(root, "platform willing to grant", control);
+ }
+
+ dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n",
+ acpi_format_exception(status));
}
}
--
2.31.1