diff options
author | Bjorn Helgaas <bhelgaas@google.com> | 2019-11-28 08:54:29 -0600 |
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committer | Bjorn Helgaas <bhelgaas@google.com> | 2019-11-28 08:54:29 -0600 |
commit | abd05c97f9711a4baa8cd43832893b8df45d459e (patch) | |
tree | c2ec4d6561dcc45bd87db28ade6a212dcdc29a19 /drivers/pci/pcie | |
parent | c2a3d213d1bc007683f63790b1cf522d5586d1a8 (diff) | |
parent | 87e90283c94c76ee11d379ab5a0973382bbd0baf (diff) | |
download | linux-abd05c97f9711a4baa8cd43832893b8df45d459e.tar.bz2 |
Merge branch 'pci/aspm'
- Remove unnecessary ASPM locking (Bjorn Helgaas)
- Add support for disabling L1 PM Substates (Heiner Kallweit)
- Allow re-enabling Clock PM after it has been disabled (Heiner Kallweit)
- Add sysfs attributes for controlling ASPM link states (Heiner Kallweit)
- Remove CONFIG_PCIEASPM_DEBUG, including "link_state" and "clk_ctl"
sysfs files (Heiner Kallweit)
* pci/aspm:
PCI/ASPM: Remove PCIEASPM_DEBUG Kconfig option and related code
PCI/ASPM: Add sysfs attributes for controlling ASPM link states
PCI/ASPM: Add pcie_aspm_get_link()
PCI/ASPM: Allow re-enabling Clock PM
PCI/ASPM: Add L1 PM substate support to pci_disable_link_state()
PCI/ASPM: Remove pcie_aspm_enabled() unnecessary locking
Diffstat (limited to 'drivers/pci/pcie')
-rw-r--r-- | drivers/pci/pcie/Kconfig | 7 | ||||
-rw-r--r-- | drivers/pci/pcie/aspm.c | 245 |
2 files changed, 154 insertions, 98 deletions
diff --git a/drivers/pci/pcie/Kconfig b/drivers/pci/pcie/Kconfig index 362eb8cfa53b..a2e862d4ec21 100644 --- a/drivers/pci/pcie/Kconfig +++ b/drivers/pci/pcie/Kconfig @@ -79,13 +79,6 @@ config PCIEASPM When in doubt, say Y. -config PCIEASPM_DEBUG - bool "Debug PCI Express ASPM" - depends on PCIEASPM - help - This enables PCI Express ASPM debug support. It will add per-device - interface to control ASPM. - choice prompt "Default ASPM policy" default PCIEASPM_DEFAULT diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 652ef23bba35..0dcd44308228 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -64,6 +64,7 @@ struct pcie_link_state { u32 clkpm_capable:1; /* Clock PM capable? */ u32 clkpm_enabled:1; /* Current Clock PM state */ u32 clkpm_default:1; /* Default Clock PM state by BIOS */ + u32 clkpm_disable:1; /* Clock PM disabled */ /* Exit latencies */ struct aspm_latency latency_up; /* Upstream direction exit latency */ @@ -161,8 +162,11 @@ static void pcie_set_clkpm_nocheck(struct pcie_link_state *link, int enable) static void pcie_set_clkpm(struct pcie_link_state *link, int enable) { - /* Don't enable Clock PM if the link is not Clock PM capable */ - if (!link->clkpm_capable) + /* + * Don't enable Clock PM if the link is not Clock PM capable + * or Clock PM is disabled + */ + if (!link->clkpm_capable || link->clkpm_disable) enable = 0; /* Need nothing if the specified equals to current state */ if (link->clkpm_enabled == enable) @@ -192,7 +196,8 @@ static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist) } link->clkpm_enabled = enabled; link->clkpm_default = enabled; - link->clkpm_capable = (blacklist) ? 0 : capable; + link->clkpm_capable = capable; + link->clkpm_disable = blacklist ? 1 : 0; } static bool pcie_retrain_link(struct pcie_link_state *link) @@ -894,6 +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. @@ -955,6 +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: @@ -1061,19 +1076,26 @@ void pcie_aspm_powersave_config_link(struct pci_dev *pdev) up_read(&pci_bus_sem); } -static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem) +static struct pcie_link_state *pcie_aspm_get_link(struct pci_dev *pdev) { - struct pci_dev *parent = pdev->bus->self; - struct pcie_link_state *link; + struct pci_dev *bridge; if (!pci_is_pcie(pdev)) - return 0; + return NULL; - if (pcie_downstream_port(pdev)) - parent = pdev; - if (!parent || !parent->link_state) - return -EINVAL; + bridge = pci_upstream_bridge(pdev); + if (!bridge || !pci_is_pcie(bridge)) + return NULL; + return bridge->link_state; +} + +static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem) +{ + struct pcie_link_state *link = pcie_aspm_get_link(pdev); + + if (!link) + return -EINVAL; /* * A driver requested that ASPM be disabled on this device, but * if we don't have permission to manage ASPM (e.g., on ACPI @@ -1090,17 +1112,24 @@ static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem) if (sem) down_read(&pci_bus_sem); mutex_lock(&aspm_lock); - link = parent->link_state; if (state & PCIE_LINK_STATE_L0S) link->aspm_disable |= ASPM_STATE_L0S; if (state & PCIE_LINK_STATE_L1) - link->aspm_disable |= ASPM_STATE_L1; + /* L1 PM substates require L1 */ + link->aspm_disable |= ASPM_STATE_L1 | ASPM_STATE_L1SS; + if (state & PCIE_LINK_STATE_L1_1) + link->aspm_disable |= ASPM_STATE_L1_1; + if (state & PCIE_LINK_STATE_L1_2) + link->aspm_disable |= ASPM_STATE_L1_2; + if (state & PCIE_LINK_STATE_L1_1_PCIPM) + link->aspm_disable |= ASPM_STATE_L1_1_PCIPM; + if (state & PCIE_LINK_STATE_L1_2_PCIPM) + link->aspm_disable |= ASPM_STATE_L1_2_PCIPM; pcie_config_aspm_link(link, policy_to_aspm_state(link)); - if (state & PCIE_LINK_STATE_CLKPM) { - link->clkpm_capable = 0; - pcie_set_clkpm(link, 0); - } + if (state & PCIE_LINK_STATE_CLKPM) + link->clkpm_disable = 1; + pcie_set_clkpm(link, policy_to_clkpm_state(link)); mutex_unlock(&aspm_lock); if (sem) up_read(&pci_bus_sem); @@ -1172,127 +1201,161 @@ module_param_call(policy, pcie_aspm_set_policy, pcie_aspm_get_policy, /** * pcie_aspm_enabled - Check if PCIe ASPM has been enabled for a device. * @pdev: Target device. + * + * Relies on the upstream bridge's link_state being valid. The link_state + * is deallocated only when the last child of the bridge (i.e., @pdev or a + * sibling) is removed, and the caller should be holding a reference to + * @pdev, so this should be safe. */ bool pcie_aspm_enabled(struct pci_dev *pdev) { - struct pci_dev *bridge = pci_upstream_bridge(pdev); - bool ret; + struct pcie_link_state *link = pcie_aspm_get_link(pdev); - if (!bridge) + if (!link) return false; - mutex_lock(&aspm_lock); - ret = bridge->link_state ? !!bridge->link_state->aspm_enabled : false; - mutex_unlock(&aspm_lock); - - return ret; + return link->aspm_enabled; } EXPORT_SYMBOL_GPL(pcie_aspm_enabled); -#ifdef CONFIG_PCIEASPM_DEBUG -static ssize_t link_state_show(struct device *dev, - struct device_attribute *attr, - char *buf) +static ssize_t aspm_attr_show_common(struct device *dev, + struct device_attribute *attr, + char *buf, u8 state) { - struct pci_dev *pci_device = to_pci_dev(dev); - struct pcie_link_state *link_state = pci_device->link_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_state->aspm_enabled); + return sprintf(buf, "%d\n", (link->aspm_enabled & state) ? 1 : 0); } -static ssize_t link_state_store(struct device *dev, - struct device_attribute *attr, - const char *buf, - size_t n) +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, *root = pdev->link_state->root; - u32 state; - - if (aspm_disabled) - return -EPERM; + struct pcie_link_state *link = pcie_aspm_get_link(pdev); + bool state_enable; - if (kstrtouint(buf, 10, &state)) - return -EINVAL; - if ((state & ~ASPM_STATE_ALL) != 0) + if (strtobool(buf, &state_enable) < 0) return -EINVAL; down_read(&pci_bus_sem); mutex_lock(&aspm_lock); - list_for_each_entry(link, &link_list, sibling) { - if (link->root != root) - continue; - pcie_config_aspm_link(link, state); + + 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 n; + + return len; } -static ssize_t clk_ctl_show(struct device *dev, - struct device_attribute *attr, - char *buf) +#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 *pci_device = to_pci_dev(dev); - struct pcie_link_state *link_state = pci_device->link_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_state->clkpm_enabled); + return sprintf(buf, "%d\n", link->clkpm_enabled); } -static ssize_t clk_ctl_store(struct device *dev, - struct device_attribute *attr, - const char *buf, - size_t n) +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); - bool state; + struct pcie_link_state *link = pcie_aspm_get_link(pdev); + bool state_enable; - if (strtobool(buf, &state)) + if (strtobool(buf, &state_enable) < 0) return -EINVAL; down_read(&pci_bus_sem); mutex_lock(&aspm_lock); - pcie_set_clkpm_nocheck(pdev->link_state, state); + + link->clkpm_disable = !state_enable; + pcie_set_clkpm(link, policy_to_clkpm_state(link)); + mutex_unlock(&aspm_lock); up_read(&pci_bus_sem); - return n; + return len; } -static DEVICE_ATTR_RW(link_state); -static DEVICE_ATTR_RW(clk_ctl); +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 char power_group[] = "power"; -void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev) +static umode_t aspm_ctrl_attrs_are_visible(struct kobject *kobj, + struct attribute *a, int n) { - struct pcie_link_state *link_state = pdev->link_state; - - if (!link_state) - return; - - if (link_state->aspm_support) - sysfs_add_file_to_group(&pdev->dev.kobj, - &dev_attr_link_state.attr, power_group); - if (link_state->clkpm_capable) - sysfs_add_file_to_group(&pdev->dev.kobj, - &dev_attr_clk_ctl.attr, power_group); -} + 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, + }; -void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev) -{ - struct pcie_link_state *link_state = pdev->link_state; + if (aspm_disabled || !link) + return 0; - if (!link_state) - return; + if (n == 0) + return link->clkpm_capable ? a->mode : 0; - if (link_state->aspm_support) - sysfs_remove_file_from_group(&pdev->dev.kobj, - &dev_attr_link_state.attr, power_group); - if (link_state->clkpm_capable) - sysfs_remove_file_from_group(&pdev->dev.kobj, - &dev_attr_clk_ctl.attr, power_group); + return link->aspm_capable & aspm_state_map[n - 1] ? a->mode : 0; } -#endif + +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) { |