kernel_optimize_test/drivers/acpi/pci_root.c
Matthew Garrett 387d37577f PCI: Don't clear ASPM bits when the FADT declares it's unsupported
Communications with a hardware vendor confirm that the expected behaviour
on systems that set the FADT ASPM disable bit but which still grant full
PCIe control is for the OS to leave any BIOS configuration intact and
refuse to touch the ASPM bits.  This mimics the behaviour of Windows.

Signed-off-by: Matthew Garrett <mjg59@coreos.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-04-09 14:20:11 -05:00

668 lines
18 KiB
C

/*
* pci_root.c - ACPI PCI Root Bridge Driver ($Revision: 40 $)
*
* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/pci.h>
#include <linux/pci-acpi.h>
#include <linux/pci-aspm.h>
#include <linux/dmar.h>
#include <linux/acpi.h>
#include <linux/slab.h>
#include <linux/dmi.h>
#include <acpi/apei.h> /* for acpi_hest_init() */
#include "internal.h"
#define _COMPONENT ACPI_PCI_COMPONENT
ACPI_MODULE_NAME("pci_root");
#define ACPI_PCI_ROOT_CLASS "pci_bridge"
#define ACPI_PCI_ROOT_DEVICE_NAME "PCI Root Bridge"
static int acpi_pci_root_add(struct acpi_device *device,
const struct acpi_device_id *not_used);
static void acpi_pci_root_remove(struct acpi_device *device);
static int acpi_pci_root_scan_dependent(struct acpi_device *adev)
{
acpiphp_check_host_bridge(adev);
return 0;
}
#define ACPI_PCIE_REQ_SUPPORT (OSC_PCI_EXT_CONFIG_SUPPORT \
| OSC_PCI_ASPM_SUPPORT \
| OSC_PCI_CLOCK_PM_SUPPORT \
| OSC_PCI_MSI_SUPPORT)
static const struct acpi_device_id root_device_ids[] = {
{"PNP0A03", 0},
{"", 0},
};
static struct acpi_scan_handler pci_root_handler = {
.ids = root_device_ids,
.attach = acpi_pci_root_add,
.detach = acpi_pci_root_remove,
.hotplug = {
.enabled = true,
.scan_dependent = acpi_pci_root_scan_dependent,
},
};
static DEFINE_MUTEX(osc_lock);
/**
* acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
* @handle - the ACPI CA node in question.
*
* Note: we could make this API take a struct acpi_device * instead, but
* for now, it's more convenient to operate on an acpi_handle.
*/
int acpi_is_root_bridge(acpi_handle handle)
{
int ret;
struct acpi_device *device;
ret = acpi_bus_get_device(handle, &device);
if (ret)
return 0;
ret = acpi_match_device_ids(device, root_device_ids);
if (ret)
return 0;
else
return 1;
}
EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
static acpi_status
get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
{
struct resource *res = data;
struct acpi_resource_address64 address;
acpi_status status;
status = acpi_resource_to_address64(resource, &address);
if (ACPI_FAILURE(status))
return AE_OK;
if ((address.address.address_length > 0) &&
(address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
res->start = address.address.minimum;
res->end = address.address.minimum + address.address.address_length - 1;
}
return AE_OK;
}
static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
struct resource *res)
{
acpi_status status;
res->start = -1;
status =
acpi_walk_resources(handle, METHOD_NAME__CRS,
get_root_bridge_busnr_callback, res);
if (ACPI_FAILURE(status))
return status;
if (res->start == -1)
return AE_ERROR;
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,
const u32 *capbuf, u32 *retval)
{
struct acpi_osc_context context = {
.uuid_str = pci_osc_uuid_str,
.rev = 1,
.cap.length = 12,
.cap.pointer = (void *)capbuf,
};
acpi_status status;
status = acpi_run_osc(handle, &context);
if (ACPI_SUCCESS(status)) {
*retval = *((u32 *)(context.ret.pointer + 8));
kfree(context.ret.pointer);
}
return status;
}
static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
u32 support,
u32 *control)
{
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)
{
acpi_status status;
mutex_lock(&osc_lock);
status = acpi_pci_query_osc(root, flags, NULL);
mutex_unlock(&osc_lock);
return status;
}
struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
{
struct acpi_pci_root *root;
struct acpi_device *device;
if (acpi_bus_get_device(handle, &device) ||
acpi_match_device_ids(device, root_device_ids))
return NULL;
root = acpi_driver_data(device);
return root;
}
EXPORT_SYMBOL_GPL(acpi_pci_find_root);
struct acpi_handle_node {
struct list_head node;
acpi_handle handle;
};
/**
* acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
* @handle: the handle in question
*
* Given an ACPI CA handle, the desired PCI device is located in the
* list of PCI devices.
*
* If the device is found, its reference count is increased and this
* function returns a pointer to its data structure. The caller must
* decrement the reference count by calling pci_dev_put().
* If no device is found, %NULL is returned.
*/
struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
{
int dev, fn;
unsigned long long adr;
acpi_status status;
acpi_handle phandle;
struct pci_bus *pbus;
struct pci_dev *pdev = NULL;
struct acpi_handle_node *node, *tmp;
struct acpi_pci_root *root;
LIST_HEAD(device_list);
/*
* Walk up the ACPI CA namespace until we reach a PCI root bridge.
*/
phandle = handle;
while (!acpi_is_root_bridge(phandle)) {
node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
if (!node)
goto out;
INIT_LIST_HEAD(&node->node);
node->handle = phandle;
list_add(&node->node, &device_list);
status = acpi_get_parent(phandle, &phandle);
if (ACPI_FAILURE(status))
goto out;
}
root = acpi_pci_find_root(phandle);
if (!root)
goto out;
pbus = root->bus;
/*
* Now, walk back down the PCI device tree until we return to our
* original handle. Assumes that everything between the PCI root
* bridge and the device we're looking for must be a P2P bridge.
*/
list_for_each_entry(node, &device_list, node) {
acpi_handle hnd = node->handle;
status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
if (ACPI_FAILURE(status))
goto out;
dev = (adr >> 16) & 0xffff;
fn = adr & 0xffff;
pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
if (!pdev || hnd == handle)
break;
pbus = pdev->subordinate;
pci_dev_put(pdev);
/*
* This function may be called for a non-PCI device that has a
* PCI parent (eg. a disk under a PCI SATA controller). In that
* case pdev->subordinate will be NULL for the parent.
*/
if (!pbus) {
dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
pdev = NULL;
break;
}
}
out:
list_for_each_entry_safe(node, tmp, &device_list, node)
kfree(node);
return pdev;
}
EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
/**
* acpi_pci_osc_control_set - Request control of PCI root _OSC features.
* @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
* @mask: Mask of _OSC bits to request control of, place to store control mask.
* @req: Mask of _OSC bits the control of is essential to the caller.
*
* Run _OSC query for @mask and if that is successful, compare the returned
* mask of control bits with @req. If all of the @req bits are set in the
* returned mask, run _OSC request for it.
*
* The variable at the @mask address may be modified regardless of whether or
* not the function returns success. On success it will contain the mask of
* _OSC bits the BIOS has granted control of, but its contents are meaningless
* on failure.
**/
acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
{
struct acpi_pci_root *root;
acpi_status status = AE_OK;
u32 ctrl, capbuf[3];
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;
mutex_lock(&osc_lock);
*mask = ctrl | root->osc_control_set;
/* No need to evaluate _OSC if the control was already granted. */
if ((root->osc_control_set & ctrl) == ctrl)
goto out;
/* Need to check the available controls bits before requesting them. */
while (*mask) {
status = acpi_pci_query_osc(root, root->osc_support_set, mask);
if (ACPI_FAILURE(status))
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;
}
capbuf[OSC_QUERY_DWORD] = 0;
capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set;
capbuf[OSC_CONTROL_DWORD] = ctrl;
status = acpi_pci_run_osc(handle, capbuf, mask);
if (ACPI_SUCCESS(status))
root->osc_control_set = *mask;
out:
mutex_unlock(&osc_lock);
return status;
}
EXPORT_SYMBOL(acpi_pci_osc_control_set);
static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
{
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 (dmi_match(DMI_SYS_VENDOR, "Apple Inc.")) {
root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;
decode_osc_control(root, "OS assumes control of",
root->osc_control_set);
return;
}
/*
* All supported architectures that use ACPI have support for
* PCI domains, so we indicate this in _OSC support capabilities.
*/
support = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
if (pci_ext_cfg_avail())
support |= OSC_PCI_EXT_CONFIG_SUPPORT;
if (pcie_aspm_support_enabled())
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",
acpi_format_exception(status));
*no_aspm = 1;
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_NATIVE_HP_CONTROL
| OSC_PCI_EXPRESS_PME_CONTROL;
if (pci_aer_available()) {
if (aer_acpi_firmware_first())
dev_info(&device->dev,
"PCIe AER handled by firmware\n");
else
control |= OSC_PCI_EXPRESS_AER_CONTROL;
}
requested = control;
status = acpi_pci_osc_control_set(handle, &control,
OSC_PCI_EXPRESS_CAPABILITY_CONTROL);
if (ACPI_SUCCESS(status)) {
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
* it's unsupported. Leave existing configuration
* intact and prevent the OS from touching it.
*/
dev_info(&device->dev, "FADT indicates ASPM is unsupported, using BIOS configuration\n");
*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 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
* properly handle PCIe 1.1 devices. So we set this
* flag here, to defer the action until after the ACPI
* root scan.
*/
*no_aspm = 1;
}
}
static int acpi_pci_root_add(struct acpi_device *device,
const struct acpi_device_id *not_used)
{
unsigned long long segment, bus;
acpi_status status;
int result;
struct acpi_pci_root *root;
acpi_handle handle = device->handle;
int no_aspm = 0;
bool hotadd = system_state != SYSTEM_BOOTING;
root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
if (!root)
return -ENOMEM;
segment = 0;
status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL,
&segment);
if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
dev_err(&device->dev, "can't evaluate _SEG\n");
result = -ENODEV;
goto end;
}
/* Check _CRS first, then _BBN. If no _BBN, default to zero. */
root->secondary.flags = IORESOURCE_BUS;
status = try_get_root_bridge_busnr(handle, &root->secondary);
if (ACPI_FAILURE(status)) {
/*
* We need both the start and end of the downstream bus range
* to interpret _CBA (MMCONFIG base address), so it really is
* supposed to be in _CRS. If we don't find it there, all we
* can do is assume [_BBN-0xFF] or [0-0xFF].
*/
root->secondary.end = 0xFF;
dev_warn(&device->dev,
FW_BUG "no secondary bus range in _CRS\n");
status = acpi_evaluate_integer(handle, METHOD_NAME__BBN,
NULL, &bus);
if (ACPI_SUCCESS(status))
root->secondary.start = bus;
else if (status == AE_NOT_FOUND)
root->secondary.start = 0;
else {
dev_err(&device->dev, "can't evaluate _BBN\n");
result = -ENODEV;
goto end;
}
}
root->device = device;
root->segment = segment & 0xFFFF;
strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
device->driver_data = root;
if (hotadd && dmar_device_add(handle)) {
result = -ENXIO;
goto end;
}
pr_info(PREFIX "%s [%s] (domain %04x %pR)\n",
acpi_device_name(device), acpi_device_bid(device),
root->segment, &root->secondary);
root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
negotiate_os_control(root, &no_aspm);
/*
* TBD: Need PCI interface for enumeration/configuration of roots.
*/
/*
* Scan the Root Bridge
* --------------------
* Must do this prior to any attempt to bind the root device, as the
* PCI namespace does not get created until this call is made (and
* thus the root bridge's pci_dev does not exist).
*/
root->bus = pci_acpi_scan_root(root);
if (!root->bus) {
dev_err(&device->dev,
"Bus %04x:%02x not present in PCI namespace\n",
root->segment, (unsigned int)root->secondary.start);
device->driver_data = NULL;
result = -ENODEV;
goto remove_dmar;
}
if (no_aspm)
pcie_no_aspm();
pci_acpi_add_bus_pm_notifier(device);
if (device->wakeup.flags.run_wake)
device_set_run_wake(root->bus->bridge, true);
if (hotadd) {
pcibios_resource_survey_bus(root->bus);
pci_assign_unassigned_root_bus_resources(root->bus);
acpi_ioapic_add(root);
}
pci_lock_rescan_remove();
pci_bus_add_devices(root->bus);
pci_unlock_rescan_remove();
return 1;
remove_dmar:
if (hotadd)
dmar_device_remove(handle);
end:
kfree(root);
return result;
}
static void acpi_pci_root_remove(struct acpi_device *device)
{
struct acpi_pci_root *root = acpi_driver_data(device);
pci_lock_rescan_remove();
pci_stop_root_bus(root->bus);
WARN_ON(acpi_ioapic_remove(root));
device_set_run_wake(root->bus->bridge, false);
pci_acpi_remove_bus_pm_notifier(device);
pci_remove_root_bus(root->bus);
dmar_device_remove(device->handle);
pci_unlock_rescan_remove();
kfree(root);
}
void __init acpi_pci_root_init(void)
{
acpi_hest_init();
if (acpi_pci_disabled)
return;
pci_acpi_crs_quirks();
acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root");
}