[v7,4/5] PCI/ASPM: Add sysfs attributes for controlling ASPM link states

Message ID	b1c83f8a-9bf6-eac5-82d0-cf5b90128fbf@gmail.com (mailing list archive)
State	Not Applicable, archived
Headers	show Return-Path: <SRS0=Qcqn=X6=vger.kernel.org=linux-pci-owner@kernel.org> Subject: [PATCH v7 4/5] PCI/ASPM: Add sysfs attributes for controlling ASPM link states From: Heiner Kallweit <hkallweit1@gmail.com> To: Frederick Lawler <fred@fredlawl.com>, Bjorn Helgaas <bhelgaas@google.com>, Greg KH <gregkh@linuxfoundation.org>, Rajat Jain <rajatja@google.com> Cc: "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org> References: <e1c28e25-df18-16e1-3e9f-933f613ea858@gmail.com> Message-ID: <b1c83f8a-9bf6-eac5-82d0-cf5b90128fbf@gmail.com> Date: Sat, 5 Oct 2019 14:07:56 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <e1c28e25-df18-16e1-3e9f-933f613ea858@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-pci-owner@vger.kernel.org Precedence: bulk
Series	PCI/ASPM: Add sysfs attributes for controlling ASPM \| expand [v7,0/5] PCI/ASPM: Add sysfs attributes for controlling ASPM [v7,2/5] PCI/ASPM: Allow to re-enable Clock PM [v7,1/5] PCI/ASPM: Add L1 sub-state support to pci_disable_link_state [v7,3/5] PCI/ASPM: Add and use helper pcie_aspm_get_link [v7,4/5] PCI/ASPM: Add sysfs attributes for controlling ASPM link states [v7,5/5] PCI/ASPM: Remove Kconfig option PCIEASPM_DEBUG and related code

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index 8bfee557e..c86c8ab00 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -347,3 +347,17 @@ 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_pm/clkpm + /sys/bus/pci/devices/.../link_pm/l0s_aspm + /sys/bus/pci/devices/.../link_pm/l1_aspm + /sys/bus/pci/devices/.../link_pm/l1_1_aspm + /sys/bus/pci/devices/.../link_pm/l1_2_aspm + /sys/bus/pci/devices/.../link_pm/l1_1_pcipm + /sys/bus/pci/devices/.../link_pm/l1_2_pcipm +Date: October 2019 +Contact: Heiner Kallweit <hkallweit1@gmail.com> +Description: If ASPM is supported for an endpoint, then 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. diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 793412954..0e76c02e0 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -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, }; diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 3f6947ee3..b2cd21e8c 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -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 */ diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 91cfea673..05ea02abf 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -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 +968,9 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev) pcie_set_clkpm(link, policy_to_clkpm_state(link)); } + /* Update visibility of ASPM sysfs attributes */ + pcie_aspm_update_sysfs_visibility(pdev); + unlock: mutex_unlock(&aspm_lock); out: @@ -1315,6 +1326,169 @@ 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; + bool enabled; + + link = pcie_aspm_get_link(pdev); + + mutex_lock(&aspm_lock); + enabled = link->aspm_enabled & state; + mutex_unlock(&aspm_lock); + + return sprintf(buf, "%d\n", enabled ? 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; + bool state_enable; + + link = pcie_aspm_get_link(pdev); + + 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 sub-states */ + 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; + int val; + + link = pcie_aspm_get_link(pdev); + + mutex_lock(&aspm_lock); + val = link->clkpm_enabled; + mutex_unlock(&aspm_lock); + + return sprintf(buf, "%d\n", val); +} + +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; + bool state_enable; + + link = pcie_aspm_get_link(pdev); + + 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 = NULL; + 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) + return 0; + + if (pci_is_pcie(pdev)) + link = pcie_aspm_get_link(pdev); + + if (!link) + return 0; + + if (n) + return link->aspm_capable & aspm_state_map[n - 1] ? a->mode : 0; + else + return link->clkpm_capable ? a->mode : 0; +} + +const struct attribute_group aspm_ctrl_attr_group = { + .name = "link_pm", + .attrs = aspm_ctrl_attrs, + .is_visible = aspm_ctrl_attrs_are_visible, +}; + static int __init pcie_aspm_disable(char *str) { if (!strcmp(str, "off")) {

[v7,4/5] PCI/ASPM: Add sysfs attributes for controlling ASPM link states

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