korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-26 05:34:13 +08:00
Code Issues Packages Projects Releases Wiki Activity

PCI/ASPM: Add sysfs attributes for controlling ASPM link states

Browse Source 
Add sysfs attributes to Endpoints and other Upstream Ports to control ASPM,
Clock PM, and L1 PM Substates.  The new attributes are:

  /sys/devices/pci*/.../link/clkpm
  /sys/devices/pci*/.../link/l0s_aspm
  /sys/devices/pci*/.../link/l1_aspm
  /sys/devices/pci*/.../link/l1_1_aspm
  /sys/devices/pci*/.../link/l1_2_aspm
  /sys/devices/pci*/.../link/l1_1_pcipm
  /sys/devices/pci*/.../link/l1_2_pcipm

An attribute is only visible if both ends of the Link leading to the device
support the state.  Writing y/1/on to the file enables the state; n/0/off
disables it.

These attributes can be used to tune the power/performance tradeoff for
individual devices.

[bhelgaas: commit log, rename directory to "link"]
Link: https://lore.kernel.org/r/b1c83f8a-9bf6-eac5-82d0-cf5b90128fbf@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Heiner Kallweit 2019-10-05 14:07:56 +02:00 committed by Bjorn Helgaas
parent 687aaf386a
commit 72ea91afbf
4 changed files with 169 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
Documentation/ABI/testing/sysfs-bus-pci
View File

@ -347,3 +347,16 @@ Description:
If the device has any Peer-to-Peer memory registered, this
file contains a '1' if the memory has been published for
use outside the driver that owns the device.
What: /sys/bus/pci/devices/.../link/clkpm
/sys/bus/pci/devices/.../link/l0s_aspm
/sys/bus/pci/devices/.../link/l1_aspm
/sys/bus/pci/devices/.../link/l1_1_aspm
/sys/bus/pci/devices/.../link/l1_2_aspm
/sys/bus/pci/devices/.../link/l1_1_pcipm
/sys/bus/pci/devices/.../link/l1_2_pcipm
Date: October 2019
Contact: Heiner Kallweit <hkallweit1@gmail.com>
Description: If ASPM is supported for an endpoint, these files can be
used to disable or enable the individual power management
states. Write y/1/on to enable, n/0/off to disable.

3
drivers/pci/pci-sysfs.c
View File

@ -1587,6 +1587,9 @@ static const struct attribute_group *pci_dev_attr_groups[] = {
&pcie_dev_attr_group,
#ifdef CONFIG_PCIEAER
&aer_stats_attr_group,
#endif
#ifdef CONFIG_PCIEASPM
&aspm_ctrl_attr_group,
#endif
NULL,
};

4
drivers/pci/pci.h
View File

@ -667,4 +667,8 @@ static inline int pci_acpi_program_hp_params(struct pci_dev *dev)
}
#endif
#ifdef CONFIG_PCIEASPM
extern const struct attribute_group aspm_ctrl_attr_group;
#endif
#endif /* DRIVERS_PCI_H */

149
drivers/pci/pcie/aspm.c
View File

@ -899,6 +899,14 @@ static struct pcie_link_state *alloc_pcie_link_state(struct pci_dev *pdev)
return link;
}
static void pcie_aspm_update_sysfs_visibility(struct pci_dev *pdev)
{
struct pci_dev *child;
list_for_each_entry(child, &pdev->subordinate->devices, bus_list)
sysfs_update_group(&child->dev.kobj, &aspm_ctrl_attr_group);
}
/*
* pcie_aspm_init_link_state: Initiate PCI express link state.
* It is called after the pcie and its children devices are scanned.
@ -960,6 +968,8 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev)
pcie_set_clkpm(link, policy_to_clkpm_state(link));
}
pcie_aspm_update_sysfs_visibility(pdev);
unlock:
mutex_unlock(&aspm_lock);
out:
@ -1313,6 +1323,145 @@ void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev)
}
#endif
static ssize_t aspm_attr_show_common(struct device *dev,
struct device_attribute *attr,
char *buf, u8 state)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct pcie_link_state *link = pcie_aspm_get_link(pdev);
return sprintf(buf, "%d\n", (link->aspm_enabled & state) ? 1 : 0);
}
static ssize_t aspm_attr_store_common(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len, u8 state)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct pcie_link_state *link = pcie_aspm_get_link(pdev);
bool state_enable;
if (strtobool(buf, &state_enable) < 0)
return -EINVAL;
down_read(&pci_bus_sem);
mutex_lock(&aspm_lock);
if (state_enable) {
link->aspm_disable &= ~state;
/* need to enable L1 for substates */
if (state & ASPM_STATE_L1SS)
link->aspm_disable &= ~ASPM_STATE_L1;
} else {
link->aspm_disable |= state;
}
pcie_config_aspm_link(link, policy_to_aspm_state(link));
mutex_unlock(&aspm_lock);
up_read(&pci_bus_sem);
return len;
}
#define ASPM_ATTR(_f, _s) \
static ssize_t _f##_show(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ return aspm_attr_show_common(dev, attr, buf, ASPM_STATE_##_s); } \
\
static ssize_t _f##_store(struct device *dev, \
struct device_attribute *attr, \
const char *buf, size_t len) \
{ return aspm_attr_store_common(dev, attr, buf, len, ASPM_STATE_##_s); }
ASPM_ATTR(l0s_aspm, L0S)
ASPM_ATTR(l1_aspm, L1)
ASPM_ATTR(l1_1_aspm, L1_1)
ASPM_ATTR(l1_2_aspm, L1_2)
ASPM_ATTR(l1_1_pcipm, L1_1_PCIPM)
ASPM_ATTR(l1_2_pcipm, L1_2_PCIPM)
static ssize_t clkpm_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct pcie_link_state *link = pcie_aspm_get_link(pdev);
return sprintf(buf, "%d\n", link->clkpm_enabled);
}
static ssize_t clkpm_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct pcie_link_state *link = pcie_aspm_get_link(pdev);
bool state_enable;
if (strtobool(buf, &state_enable) < 0)
return -EINVAL;
down_read(&pci_bus_sem);
mutex_lock(&aspm_lock);
link->clkpm_disable = !state_enable;
pcie_set_clkpm(link, policy_to_clkpm_state(link));
mutex_unlock(&aspm_lock);
up_read(&pci_bus_sem);
return len;
}
static DEVICE_ATTR_RW(clkpm);
static DEVICE_ATTR_RW(l0s_aspm);
static DEVICE_ATTR_RW(l1_aspm);
static DEVICE_ATTR_RW(l1_1_aspm);
static DEVICE_ATTR_RW(l1_2_aspm);
static DEVICE_ATTR_RW(l1_1_pcipm);
static DEVICE_ATTR_RW(l1_2_pcipm);
static struct attribute *aspm_ctrl_attrs[] = {
&dev_attr_clkpm.attr,
&dev_attr_l0s_aspm.attr,
&dev_attr_l1_aspm.attr,
&dev_attr_l1_1_aspm.attr,
&dev_attr_l1_2_aspm.attr,
&dev_attr_l1_1_pcipm.attr,
&dev_attr_l1_2_pcipm.attr,
NULL
};
static umode_t aspm_ctrl_attrs_are_visible(struct kobject *kobj,
struct attribute *a, int n)
{
struct device *dev = kobj_to_dev(kobj);
struct pci_dev *pdev = to_pci_dev(dev);
struct pcie_link_state *link = pcie_aspm_get_link(pdev);
static const u8 aspm_state_map[] = {
ASPM_STATE_L0S,
ASPM_STATE_L1,
ASPM_STATE_L1_1,
ASPM_STATE_L1_2,
ASPM_STATE_L1_1_PCIPM,
ASPM_STATE_L1_2_PCIPM,
};
if (aspm_disabled || !link)
return 0;
if (n == 0)
return link->clkpm_capable ? a->mode : 0;
return link->aspm_capable & aspm_state_map[n - 1] ? a->mode : 0;
}
const struct attribute_group aspm_ctrl_attr_group = {
.name = "link",
.attrs = aspm_ctrl_attrs,
.is_visible = aspm_ctrl_attrs_are_visible,
};
static int __init pcie_aspm_disable(char *str)
{
if (!strcmp(str, "off")) {