diff options
Diffstat (limited to 'drivers/pci/pcie/aspm.c')
| -rw-r--r-- | drivers/pci/pcie/aspm.c | 165 |
1 files changed, 124 insertions, 41 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 9aad608bcf3..586b6f75910 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -17,6 +17,7 @@ #include <linux/init.h> #include <linux/slab.h> #include <linux/jiffies.h> +#include <linux/delay.h> #include <linux/pci-aspm.h> #include "../pci.h" @@ -33,6 +34,11 @@ struct endpoint_state { struct pcie_link_state { struct list_head sibiling; struct pci_dev *pdev; + bool downstream_has_switch; + + struct pcie_link_state *parent; + struct list_head children; + struct list_head link; /* ASPM state */ unsigned int support_state; @@ -70,6 +76,8 @@ static const char *policy_str[] = { [POLICY_POWERSAVE] = "powersave" }; +#define LINK_RETRAIN_TIMEOUT HZ + static int policy_to_aspm_state(struct pci_dev *pdev) { struct pcie_link_state *link_state = pdev->link_state; @@ -125,7 +133,7 @@ static void pcie_set_clock_pm(struct pci_dev *pdev, int enable) link_state->clk_pm_enabled = !!enable; } -static void pcie_check_clock_pm(struct pci_dev *pdev) +static void pcie_check_clock_pm(struct pci_dev *pdev, int blacklist) { int pos; u32 reg32; @@ -149,10 +157,26 @@ static void pcie_check_clock_pm(struct pci_dev *pdev) if (!(reg16 & PCI_EXP_LNKCTL_CLKREQ_EN)) enabled = 0; } - link_state->clk_pm_capable = capable; link_state->clk_pm_enabled = enabled; link_state->bios_clk_state = enabled; - pcie_set_clock_pm(pdev, policy_to_clkpm_state(pdev)); + if (!blacklist) { + link_state->clk_pm_capable = capable; + pcie_set_clock_pm(pdev, policy_to_clkpm_state(pdev)); + } else { + link_state->clk_pm_capable = 0; + pcie_set_clock_pm(pdev, 0); + } +} + +static bool pcie_aspm_downstream_has_switch(struct pci_dev *pdev) +{ + struct pci_dev *child_dev; + + list_for_each_entry(child_dev, &pdev->subordinate->devices, bus_list) { + if (child_dev->pcie_type == PCI_EXP_TYPE_UPSTREAM) + return true; + } + return false; } /* @@ -217,16 +241,18 @@ static void pcie_aspm_configure_common_clock(struct pci_dev *pdev) pci_write_config_word(pdev, pos + PCI_EXP_LNKCTL, reg16); /* Wait for link training end */ - /* break out after waiting for 1 second */ + /* break out after waiting for timeout */ start_jiffies = jiffies; - while ((jiffies - start_jiffies) < HZ) { + for (;;) { pci_read_config_word(pdev, pos + PCI_EXP_LNKSTA, ®16); if (!(reg16 & PCI_EXP_LNKSTA_LT)) break; - cpu_relax(); + if (time_after(jiffies, start_jiffies + LINK_RETRAIN_TIMEOUT)) + break; + msleep(1); } /* training failed -> recover */ - if ((jiffies - start_jiffies) >= HZ) { + if (reg16 & PCI_EXP_LNKSTA_LT) { dev_printk (KERN_ERR, &pdev->dev, "ASPM: Could not configure" " common clock\n"); i = 0; @@ -419,9 +445,9 @@ static unsigned int pcie_aspm_check_state(struct pci_dev *pdev, { struct pci_dev *child_dev; - /* If no child, disable the link */ + /* If no child, ignore the link */ if (list_empty(&pdev->subordinate->devices)) - return 0; + return state; list_for_each_entry(child_dev, &pdev->subordinate->devices, bus_list) { if (child_dev->pcie_type == PCI_EXP_TYPE_PCI_BRIDGE) { /* @@ -462,6 +488,9 @@ static void __pcie_aspm_config_link(struct pci_dev *pdev, unsigned int state) int valid = 1; struct pcie_link_state *link_state = pdev->link_state; + /* If no child, disable the link */ + if (list_empty(&pdev->subordinate->devices)) + state = 0; /* * if the downstream component has pci bridge function, don't do ASPM * now @@ -493,20 +522,52 @@ static void __pcie_aspm_config_link(struct pci_dev *pdev, unsigned int state) link_state->enabled_state = state; } +static struct pcie_link_state *get_root_port_link(struct pcie_link_state *link) +{ + struct pcie_link_state *root_port_link = link; + while (root_port_link->parent) + root_port_link = root_port_link->parent; + return root_port_link; +} + +/* check the whole hierarchy, and configure each link in the hierarchy */ static void __pcie_aspm_configure_link_state(struct pci_dev *pdev, unsigned int state) { struct pcie_link_state *link_state = pdev->link_state; + struct pcie_link_state *root_port_link = get_root_port_link(link_state); + struct pcie_link_state *leaf; - if (link_state->support_state == 0) - return; state &= PCIE_LINK_STATE_L0S|PCIE_LINK_STATE_L1; - /* state 0 means disabling aspm */ - state = pcie_aspm_check_state(pdev, state); + /* check all links who have specific root port link */ + list_for_each_entry(leaf, &link_list, sibiling) { + if (!list_empty(&leaf->children) || + get_root_port_link(leaf) != root_port_link) + continue; + state = pcie_aspm_check_state(leaf->pdev, state); + } + /* check root port link too in case it hasn't children */ + state = pcie_aspm_check_state(root_port_link->pdev, state); + if (link_state->enabled_state == state) return; - __pcie_aspm_config_link(pdev, state); + + /* + * we must change the hierarchy. See comments in + * __pcie_aspm_config_link for the order + **/ + if (state & PCIE_LINK_STATE_L1) { + list_for_each_entry(leaf, &link_list, sibiling) { + if (get_root_port_link(leaf) == root_port_link) + __pcie_aspm_config_link(leaf->pdev, state); + } + } else { + list_for_each_entry_reverse(leaf, &link_list, sibiling) { + if (get_root_port_link(leaf) == root_port_link) + __pcie_aspm_config_link(leaf->pdev, state); + } + } } /* @@ -570,6 +631,7 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev) unsigned int state; struct pcie_link_state *link_state; int error = 0; + int blacklist; if (aspm_disabled || !pdev->is_pcie || pdev->link_state) return; @@ -580,29 +642,58 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev) if (list_empty(&pdev->subordinate->devices)) goto out; - if (pcie_aspm_sanity_check(pdev)) - goto out; + blacklist = !!pcie_aspm_sanity_check(pdev); mutex_lock(&aspm_lock); link_state = kzalloc(sizeof(*link_state), GFP_KERNEL); if (!link_state) goto unlock_out; - pdev->link_state = link_state; - pcie_aspm_configure_common_clock(pdev); + link_state->downstream_has_switch = pcie_aspm_downstream_has_switch(pdev); + INIT_LIST_HEAD(&link_state->children); + INIT_LIST_HEAD(&link_state->link); + if (pdev->bus->self) {/* this is a switch */ + struct pcie_link_state *parent_link_state; - pcie_aspm_cap_init(pdev); + parent_link_state = pdev->bus->parent->self->link_state; + if (!parent_link_state) { + kfree(link_state); + goto unlock_out; + } + list_add(&link_state->link, &parent_link_state->children); + link_state->parent = parent_link_state; + } - /* config link state to avoid BIOS error */ - state = pcie_aspm_check_state(pdev, policy_to_aspm_state(pdev)); - __pcie_aspm_config_link(pdev, state); + pdev->link_state = link_state; - pcie_check_clock_pm(pdev); + if (!blacklist) { + pcie_aspm_configure_common_clock(pdev); + pcie_aspm_cap_init(pdev); + } else { + link_state->enabled_state = PCIE_LINK_STATE_L0S|PCIE_LINK_STATE_L1; + link_state->bios_aspm_state = 0; + /* Set support state to 0, so we will disable ASPM later */ + link_state->support_state = 0; + } link_state->pdev = pdev; list_add(&link_state->sibiling, &link_list); + if (link_state->downstream_has_switch) { + /* + * If link has switch, delay the link config. The leaf link + * initialization will config the whole hierarchy. but we must + * make sure BIOS doesn't set unsupported link state + **/ + state = pcie_aspm_check_state(pdev, link_state->bios_aspm_state); + __pcie_aspm_config_link(pdev, state); + } else + __pcie_aspm_configure_link_state(pdev, + policy_to_aspm_state(pdev)); + + pcie_check_clock_pm(pdev, blacklist); + unlock_out: if (error) free_link_state(pdev); @@ -635,6 +726,7 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev) /* All functions are removed, so just disable ASPM for the link */ __pcie_aspm_config_one_dev(parent, 0); list_del(&link_state->sibiling); + list_del(&link_state->link); /* Clock PM is for endpoint device */ free_link_state(parent); @@ -857,24 +949,15 @@ void pcie_no_aspm(void) aspm_disabled = 1; } -#ifdef CONFIG_ACPI -#include <acpi/acpi_bus.h> -#include <linux/pci-acpi.h> -static void pcie_aspm_platform_init(void) -{ - pcie_osc_support_set(OSC_ACTIVE_STATE_PWR_SUPPORT| - OSC_CLOCK_PWR_CAPABILITY_SUPPORT); -} -#else -static inline void pcie_aspm_platform_init(void) { } -#endif - -static int __init pcie_aspm_init(void) +/** + * pcie_aspm_enabled - is PCIe ASPM enabled? + * + * Returns true if ASPM has not been disabled by the command-line option + * pcie_aspm=off. + **/ +int pcie_aspm_enabled(void) { - if (aspm_disabled) - return 0; - pcie_aspm_platform_init(); - return 0; + return !aspm_disabled; } +EXPORT_SYMBOL(pcie_aspm_enabled); -fs_initcall(pcie_aspm_init); |