Commit 955f14b4 authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

PCI/ACPI: Decode _OSC bitmasks symbolically 



This updates _OSC-related messages to be more human-readable.  We now always
show the features we declare support for (this was previously invisible) as
well as the features we are granted control of.

Typical changes:

  -acpi PNP0A08:00: Requesting ACPI _OSC control (0x1d)
  -acpi PNP0A08:00: ACPI _OSC control (0x1d) granted
  +acpi PNP0A08:00: _OSC: OS supports [ExtendedConfig ASPM ClockPM Segments MSI]
  +acpi PNP0A08:00: _OSC: OS now controls [PCIeHotplug PME AER PCIeCapability]

Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Acked-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent de189662

drivers/acpi/pci_root.c

+67 −17
Original line number Diff line number Diff line
@@ -127,6 +127,55 @@ static acpi_status try_get_root_bridge_busnr(acpi_handle handle, 
	return AE_OK;

}



struct pci_osc_bit_struct {

	u32 bit;

	char *desc;

};



static struct pci_osc_bit_struct pci_osc_support_bit[] = {

	{ OSC_PCI_EXT_CONFIG_SUPPORT, "ExtendedConfig" },

	{ OSC_PCI_ASPM_SUPPORT, "ASPM" },

	{ OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" },

	{ OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" },

	{ OSC_PCI_MSI_SUPPORT, "MSI" },

};



static struct pci_osc_bit_struct pci_osc_control_bit[] = {

	{ OSC_PCI_EXPRESS_NATIVE_HP_CONTROL, "PCIeHotplug" },

	{ OSC_PCI_SHPC_NATIVE_HP_CONTROL, "SHPCHotplug" },

	{ OSC_PCI_EXPRESS_PME_CONTROL, "PME" },

	{ OSC_PCI_EXPRESS_AER_CONTROL, "AER" },

	{ OSC_PCI_EXPRESS_CAPABILITY_CONTROL, "PCIeCapability" },

};



static void decode_osc_bits(struct acpi_pci_root *root, char *msg, u32 word,

			    struct pci_osc_bit_struct *table, int size)

{

	char buf[80];

	int i, len = 0;

	struct pci_osc_bit_struct *entry;



	buf[0] = '\0';

	for (i = 0, entry = table; i < size; i++, entry++)

		if (word & entry->bit)

			len += snprintf(buf + len, sizeof(buf) - len, "%s%s",

					len ? " " : "", entry->desc);



	dev_info(&root->device->dev, "_OSC: %s [%s]\n", msg, buf);

}



static void decode_osc_support(struct acpi_pci_root *root, char *msg, u32 word)

{

	decode_osc_bits(root, msg, word, pci_osc_support_bit,

			ARRAY_SIZE(pci_osc_support_bit));

}



static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word)

{

	decode_osc_bits(root, msg, word, pci_osc_control_bit,

			ARRAY_SIZE(pci_osc_control_bit));

}



static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";



static acpi_status acpi_pci_run_osc(acpi_handle handle,
@@ -340,10 +389,14 @@ acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req) 
			goto out;

		if (ctrl == *mask)

			break;

		decode_osc_control(root, "platform does not support",

				   ctrl & ~(*mask));

		ctrl = *mask;

	}



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

		decode_osc_control(root, "not requesting control; platform does not support",

				   req & ~(ctrl));

		status = AE_SUPPORT;

		goto out;

	}
@@ -363,7 +416,7 @@ EXPORT_SYMBOL(acpi_pci_osc_control_set); 
static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,

				 int *clear_aspm)

{

	u32 support, control;

	u32 support, control, requested;

	acpi_status status;

	struct acpi_device *device = root->device;

	acpi_handle handle = device->handle;
@@ -379,6 +432,8 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm, 
		support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;

	if (pci_msi_enabled())

		support |= OSC_PCI_MSI_SUPPORT;



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

	status = acpi_pci_osc_support(root, support);

	if (ACPI_FAILURE(status)) {

		dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
@@ -393,8 +448,8 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm, 
	}



	if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {

		dev_info(&device->dev, "Not requesting _OSC control (we support %#02x but %#02x are required)\n",

			 support, ACPI_PCIE_REQ_SUPPORT);

		decode_osc_support(root, "not requesting OS control; OS requires",

				   ACPI_PCIE_REQ_SUPPORT);

		return;

	}
@@ -404,21 +459,17 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm, 


	if (pci_aer_available()) {

		if (aer_acpi_firmware_first())

			dev_dbg(&device->dev,

				"PCIe errors handled by BIOS.\n");

			dev_info(&device->dev,

				 "PCIe AER handled by firmware\n");

		else

			control |= OSC_PCI_EXPRESS_AER_CONTROL;

	}



	dev_info(&device->dev,

		 "Requesting ACPI _OSC control (0x%02x)\n", control);



	requested = control;

	status = acpi_pci_osc_control_set(handle, &control,

					  OSC_PCI_EXPRESS_CAPABILITY_CONTROL);

	if (ACPI_SUCCESS(status)) {

		dev_info(&device->dev,

			 "ACPI _OSC control (0x%02x) granted\n",

			 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
@@ -427,12 +478,11 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm, 
			*clear_aspm = 1;

		}

	} else {

		dev_info(&device->dev,

			"ACPI _OSC request failed (%s), "

			"returned control mask: 0x%02x\n",

			acpi_format_exception(status), control);

		dev_info(&device->dev,

			 "ACPI _OSC control for PCIe not granted, disabling ASPM\n");

		decode_osc_control(root, "OS requested", requested);

		decode_osc_control(root, "platform willing to grant", control);

		dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\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

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