[3/3] PCI/ASPM: add sysfs attribute for controlling ASPM

Message ID	a0c090cd-e3a4-f667-b99d-f31c48c2e0a3@gmail.com (mailing list archive)
State	New, archived
Delegated to:	Bjorn Helgaas
Headers	show Return-Path: <linux-pci-owner@kernel.org> Subject: [PATCH 3/3] PCI/ASPM: add sysfs attribute for controlling ASPM From: Heiner Kallweit <hkallweit1@gmail.com> To: Frederick Lawler <fred@fredlawl.com>, Bjorn Helgaas <bhelgaas@google.com> Cc: "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org> References: <7a6d2f14-f2a6-99ad-3a93-fdaa0726ce86@gmail.com> Message-ID: <a0c090cd-e3a4-f667-b99d-f31c48c2e0a3@gmail.com> Date: Thu, 23 May 2019 22:05:35 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <7a6d2f14-f2a6-99ad-3a93-fdaa0726ce86@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 attribute for controlling ASPM \| expand [0/3] PCI/ASPM: add sysfs attribute for controlling ASPM [1/3] PCI/ASPM: add L1 sub-state support to pci_disable_link_state [2/3] PCI/ASPM: allow to re-enable Clock PM [3/3] PCI/ASPM: add sysfs attribute for controlling ASPM

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index 8bfee557e..38fe358de 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -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/.../power/aspm_link_states +Date: May 2019 +Contact: Heiner Kallweit <hkallweit1@gmail.com> +Description: + If ASPM is supported for an endpoint, then this file can be + used to enable / disable link states. A link state + displayed in brackets is enabled, otherwise it's disabled. + To control link states (case insensitive): + +state : enables a supported state + -state : disables a state + none : disables all link states + all : enables all supported link states diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 9cb99380c..06642b7de 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -499,17 +499,13 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev); void pcie_aspm_exit_link_state(struct pci_dev *pdev); void pcie_aspm_pm_state_change(struct pci_dev *pdev); void pcie_aspm_powersave_config_link(struct pci_dev *pdev); +void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev); +void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev); #else static inline void pcie_aspm_init_link_state(struct pci_dev *pdev) { } static inline void pcie_aspm_exit_link_state(struct pci_dev *pdev) { } static inline void pcie_aspm_pm_state_change(struct pci_dev *pdev) { } static inline void pcie_aspm_powersave_config_link(struct pci_dev *pdev) { } -#endif - -#ifdef CONFIG_PCIEASPM_DEBUG -void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev); -void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev); -#else static inline void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev) { } static inline void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev) { } #endif diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 7847be38e..f3822accb 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -42,6 +42,8 @@ #define ASPM_STATE_ALL (ASPM_STATE_L0S | ASPM_STATE_L1 | \ ASPM_STATE_L1SS) +static const char power_group[] = "power"; + struct aspm_latency { u32 l0s; /* L0s latency (nsec) */ u32 l1; /* L1 latency (nsec) */ @@ -1251,38 +1253,212 @@ static ssize_t clk_ctl_store(struct device *dev, static DEVICE_ATTR_RW(link_state); static DEVICE_ATTR_RW(clk_ctl); +#endif + +struct aspm_sysfs_state { + const char *name; + int mask; +}; + +static const struct aspm_sysfs_state aspm_sysfs_states[] = { + { "L0S", ASPM_STATE_L0S }, + { "L1", ASPM_STATE_L1 }, + { "L1.1", ASPM_STATE_L1_1_MASK }, + { "L1.2", ASPM_STATE_L1_2_MASK }, +}; + +static struct pcie_link_state *aspm_get_parent_link(struct pci_dev *pdev) +{ + struct pci_dev *parent = pdev->bus->self; + + if (pdev->has_secondary_link) + parent = pdev; + + return parent ? parent->link_state : NULL; +} + +static bool pcie_check_aspm_endpoint(struct pci_dev *pdev) +{ + struct pcie_link_state *link; + + if (pci_pcie_type(pdev) != PCI_EXP_TYPE_ENDPOINT) + return false; + + link = aspm_get_parent_link(pdev); + + return link && link->aspm_support; +} + +static ssize_t aspm_link_states_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct pci_dev *pdev = to_pci_dev(dev); + struct pcie_link_state *link; + int len = 0, i; + + link = aspm_get_parent_link(pdev); + if (!link) + return -EOPNOTSUPP; + + mutex_lock(&aspm_lock); + + for (i = 0; i < ARRAY_SIZE(aspm_sysfs_states); i++) { + const struct aspm_sysfs_state *st = aspm_sysfs_states + i; + + if (link->aspm_enabled & st->mask) + len += scnprintf(buf + len, PAGE_SIZE - len, "[%s] ", + st->name); + else + len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", + st->name); + } + + if (link->clkpm_enabled) + len += scnprintf(buf + len, PAGE_SIZE - len, "[CLKPM] "); + else + len += scnprintf(buf + len, PAGE_SIZE - len, "CLKPM "); + + mutex_unlock(&aspm_lock); + + len += scnprintf(buf + len, PAGE_SIZE - len, "\n"); + + return len; +} + +static ssize_t aspm_link_states_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; + char *buftmp = (char *)buf, *tok; + unsigned int disable_aspm, disable_clkpm; + bool first = true, add; + int err = 0, i; + + if (aspm_disabled) + return -EPERM; + + link = aspm_get_parent_link(pdev); + if (!link) + return -EOPNOTSUPP; + + down_read(&pci_bus_sem); + mutex_lock(&aspm_lock); + + disable_aspm = link->aspm_disable; + disable_clkpm = link->clkpm_disable; + + while ((tok = strsep(&buftmp, " \n")) != NULL) { + bool found = false; + + if (!*tok) + continue; + + if (first) { + if (!strcasecmp(tok, "none")) { + disable_aspm = ASPM_STATE_ALL; + disable_clkpm = 1; + break; + } + if (!strcasecmp(tok, "all")) { + disable_aspm = 0; + disable_clkpm = 0; + break; + } + first = false; + } + + if (*tok != '+' && *tok != '-') { + err = -EINVAL; + goto out; + } + + add = *tok++ == '+'; + + for (i = 0; i < ARRAY_SIZE(aspm_sysfs_states); i++) { + const struct aspm_sysfs_state *st = + aspm_sysfs_states + i; + + if (!strcasecmp(tok, st->name)) { + if (add) + disable_aspm &= ~st->mask; + else + disable_aspm |= st->mask; + found = true; + break; + } + } + + if (!found && !strcasecmp(tok, "clkpm")) { + disable_clkpm = add ? 0 : 1; + found = true; + } + + if (!found) { + err = -EINVAL; + goto out; + } + } + + if (disable_aspm & ASPM_STATE_L1) + disable_aspm |= ASPM_STATE_L1SS; + + link->aspm_disable = disable_aspm; + link->clkpm_disable = disable_clkpm; + + pcie_config_aspm_link(link, policy_to_aspm_state(link)); + pcie_set_clkpm(link, policy_to_clkpm_state(link)); +out: + mutex_unlock(&aspm_lock); + up_read(&pci_bus_sem); + + return err ?: len; +} + +static DEVICE_ATTR_RW(aspm_link_states); -static char power_group[] = "power"; void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev) { struct pcie_link_state *link_state = pdev->link_state; + if (pcie_check_aspm_endpoint(pdev)) + sysfs_add_file_to_group(&pdev->dev.kobj, + &dev_attr_aspm_link_states.attr, power_group); + if (!link_state) return; +#ifdef CONFIG_PCIEASPM_DEBUG 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); +#endif } void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev) { struct pcie_link_state *link_state = pdev->link_state; + if (pcie_check_aspm_endpoint(pdev)) + sysfs_remove_file_from_group(&pdev->dev.kobj, + &dev_attr_aspm_link_states.attr, power_group); + if (!link_state) return; +#ifdef CONFIG_PCIEASPM_DEBUG 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); -} #endif +} static int __init pcie_aspm_disable(char *str) {

[3/3] PCI/ASPM: add sysfs attribute for controlling ASPM

Commit Message

Comments

Patch