Commit 8d55770b authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

Merge branch 'pci/acpi' 

- Simplify _OSC negotiation with platform for control of PCIe features
  (Joerg Roedel)

* pci/acpi:
  PCI/ACPI: Check for _OSC support in acpi_pci_osc_control_set()
  PCI/ACPI: Move _OSC query checks to separate function
  PCI/ACPI: Move supported and control calculations to separate functions
  PCI/ACPI: Remove OSC_PCI_SUPPORT_MASKS and OSC_PCI_CONTROL_MASKS
parents e4e737bb 6bc779ee

drivers/acpi/pci_root.c

+84 −77
Original line number Diff line number Diff line
@@ -199,33 +199,20 @@ static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, 
	acpi_status status;

	u32 result, capbuf[3];



	support &= OSC_PCI_SUPPORT_MASKS;

	support |= root->osc_support_set;



	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;

	}



	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);

	if (ACPI_SUCCESS(status)) {

		root->osc_support_set = support;

		if (control)

		*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;
@@ -348,8 +335,9 @@ 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 support)

{

	u32 req = OSC_PCI_EXPRESS_CAPABILITY_CONTROL;

	struct acpi_pci_root *root;

	acpi_status status;

	u32 ctrl, capbuf[3];
@@ -357,22 +345,16 @@ static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 r 
	if (!mask)

		return AE_BAD_PARAMETER;



	ctrl = *mask & OSC_PCI_CONTROL_MASKS;

	if ((ctrl & req) != req)

		return AE_TYPE;



	root = acpi_pci_find_root(handle);

	if (!root)

		return AE_NOT_EXIST;



	*mask = ctrl | root->osc_control_set;

	/* No need to evaluate _OSC if the control was already granted. */

	if ((root->osc_control_set & ctrl) == ctrl)

		return AE_OK;

	ctrl   = *mask;

	*mask |= root->osc_control_set;



	/* Need to check the available controls bits before requesting them. */

	while (*mask) {

		status = acpi_pci_query_osc(root, root->osc_support_set, mask);

	do {

		status = acpi_pci_query_osc(root, support, mask);

		if (ACPI_FAILURE(status))

			return status;

		if (ctrl == *mask)
@@ -380,7 +362,11 @@ static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 r 
		decode_osc_control(root, "platform does not support",

				   ctrl & ~(*mask));

		ctrl = *mask;

	}

	} while (*mask);



	/* No need to request _OSC if the control was already granted. */

	if ((root->osc_control_set & ctrl) == ctrl)

		return AE_OK;



	if ((ctrl & req) != req) {

		decode_osc_control(root, "not requesting control; platform does not support",
@@ -399,25 +385,9 @@ static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 r 
	return AE_OK;

}



static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,

				 bool is_pcie)

static u32 calculate_support(void)

{

	u32 support, control, requested;

	acpi_status status;

	struct acpi_device *device = root->device;

	acpi_handle handle = device->handle;



	/*

	 * Apple always return failure on _OSC calls when _OSI("Darwin") has

	 * been called successfully. We know the feature set supported by the

	 * platform, so avoid calling _OSC at all

	 */

	if (x86_apple_machine) {

		root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;

		decode_osc_control(root, "OS assumes control of",

				   root->osc_control_set);

		return;

	}

	u32 support;



	/*

	 * All supported architectures that use ACPI have support for
@@ -434,30 +404,12 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm, 
	if (IS_ENABLED(CONFIG_PCIE_EDR))

		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)

			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;

	return support;

}



	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;

	}

static u32 calculate_control(void)

{

	u32 control;



	control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL

		| OSC_PCI_EXPRESS_PME_CONTROL;
@@ -483,11 +435,59 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm, 
	if (IS_ENABLED(CONFIG_PCIE_DPC) && IS_ENABLED(CONFIG_PCIE_EDR))

		control |= OSC_PCI_EXPRESS_DPC_CONTROL;



	requested = control;

	status = acpi_pci_osc_control_set(handle, &control,

					  OSC_PCI_EXPRESS_CAPABILITY_CONTROL);

	return control;

}



static bool os_control_query_checks(struct acpi_pci_root *root, u32 support)

{

	struct acpi_device *device = root->device;



	if (pcie_ports_disabled) {

		dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");

		return false;

	}



	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 false;

	}



	return true;

}



static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,

				 bool is_pcie)

{

	u32 support, control = 0, requested = 0;

	acpi_status status;

	struct acpi_device *device = root->device;

	acpi_handle handle = device->handle;



	/*

	 * Apple always return failure on _OSC calls when _OSI("Darwin") has

	 * been called successfully. We know the feature set supported by the

	 * platform, so avoid calling _OSC at all

	 */

	if (x86_apple_machine) {

		root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;

		decode_osc_control(root, "OS assumes control of",

				   root->osc_control_set);

		return;

	}



	support = calculate_support();



	decode_osc_support(root, "OS supports", support);



	if (os_control_query_checks(root, support))

		requested = control = calculate_control();



	status = acpi_pci_osc_control_set(handle, &control, support);

	if (ACPI_SUCCESS(status)) {

		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
@@ -498,11 +498,6 @@ 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));



		/*

		 * We want to disable ASPM here, but aspm_disabled

		 * needs to remain in its state from boot so that we
@@ -511,6 +506,18 @@ 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 (control) {

			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));

	}

}

include/linux/acpi.h

+0 −2
Original line number Diff line number Diff line
@@ -577,7 +577,6 @@ extern u32 osc_sb_native_usb4_control; 
#define OSC_PCI_MSI_SUPPORT			0x00000010

#define OSC_PCI_EDR_SUPPORT			0x00000080

#define OSC_PCI_HPX_TYPE_3_SUPPORT		0x00000100

#define OSC_PCI_SUPPORT_MASKS			0x0000019f



/* PCI Host Bridge _OSC: Capabilities DWORD 3: Control Field */

#define OSC_PCI_EXPRESS_NATIVE_HP_CONTROL	0x00000001
@@ -587,7 +586,6 @@ extern u32 osc_sb_native_usb4_control; 
#define OSC_PCI_EXPRESS_CAPABILITY_CONTROL	0x00000010

#define OSC_PCI_EXPRESS_LTR_CONTROL		0x00000020

#define OSC_PCI_EXPRESS_DPC_CONTROL		0x00000080

#define OSC_PCI_CONTROL_MASKS			0x000000bf



#define ACPI_GSB_ACCESS_ATTRIB_QUICK		0x00000002

#define ACPI_GSB_ACCESS_ATTRIB_SEND_RCV         0x00000004