| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Enable PCIe link L0s/L1 state and Clock Power Management |
| * |
| * Copyright (C) 2007 Intel |
| * Copyright (C) Zhang Yanmin (yanmin.zhang@intel.com) |
| * Copyright (C) Shaohua Li (shaohua.li@intel.com) |
| */ |
| |
| #include <linux/bitfield.h> |
| #include <linux/kernel.h> |
| #include <linux/limits.h> |
| #include <linux/math.h> |
| #include <linux/module.h> |
| #include <linux/moduleparam.h> |
| #include <linux/pci.h> |
| #include <linux/pci_regs.h> |
| #include <linux/errno.h> |
| #include <linux/pm.h> |
| #include <linux/init.h> |
| #include <linux/printk.h> |
| #include <linux/slab.h> |
| #include <linux/time.h> |
| |
| #include "../pci.h" |
| |
| #ifdef MODULE_PARAM_PREFIX |
| #undef MODULE_PARAM_PREFIX |
| #endif |
| #define MODULE_PARAM_PREFIX "pcie_aspm." |
| |
| /* Note: those are not register definitions */ |
| #define ASPM_STATE_L0S_UP (1) /* Upstream direction L0s state */ |
| #define ASPM_STATE_L0S_DW (2) /* Downstream direction L0s state */ |
| #define ASPM_STATE_L1 (4) /* L1 state */ |
| #define ASPM_STATE_L1_1 (8) /* ASPM L1.1 state */ |
| #define ASPM_STATE_L1_2 (0x10) /* ASPM L1.2 state */ |
| #define ASPM_STATE_L1_1_PCIPM (0x20) /* PCI PM L1.1 state */ |
| #define ASPM_STATE_L1_2_PCIPM (0x40) /* PCI PM L1.2 state */ |
| #define ASPM_STATE_L1_SS_PCIPM (ASPM_STATE_L1_1_PCIPM | ASPM_STATE_L1_2_PCIPM) |
| #define ASPM_STATE_L1_2_MASK (ASPM_STATE_L1_2 | ASPM_STATE_L1_2_PCIPM) |
| #define ASPM_STATE_L1SS (ASPM_STATE_L1_1 | ASPM_STATE_L1_1_PCIPM |\ |
| ASPM_STATE_L1_2_MASK) |
| #define ASPM_STATE_L0S (ASPM_STATE_L0S_UP | ASPM_STATE_L0S_DW) |
| #define ASPM_STATE_ALL (ASPM_STATE_L0S | ASPM_STATE_L1 | \ |
| ASPM_STATE_L1SS) |
| |
| struct pcie_link_state { |
| struct pci_dev *pdev; /* Upstream component of the Link */ |
| struct pci_dev *downstream; /* Downstream component, function 0 */ |
| struct pcie_link_state *root; /* pointer to the root port link */ |
| struct pcie_link_state *parent; /* pointer to the parent Link state */ |
| struct list_head sibling; /* node in link_list */ |
| |
| /* ASPM state */ |
| u32 aspm_support:7; /* Supported ASPM state */ |
| u32 aspm_enabled:7; /* Enabled ASPM state */ |
| u32 aspm_capable:7; /* Capable ASPM state with latency */ |
| u32 aspm_default:7; /* Default ASPM state by BIOS */ |
| u32 aspm_disable:7; /* Disabled ASPM state */ |
| |
| /* Clock PM 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 */ |
| }; |
| |
| static int aspm_disabled, aspm_force; |
| static bool aspm_support_enabled = true; |
| static DEFINE_MUTEX(aspm_lock); |
| static LIST_HEAD(link_list); |
| |
| #define POLICY_DEFAULT 0 /* BIOS default setting */ |
| #define POLICY_PERFORMANCE 1 /* high performance */ |
| #define POLICY_POWERSAVE 2 /* high power saving */ |
| #define POLICY_POWER_SUPERSAVE 3 /* possibly even more power saving */ |
| |
| #ifdef CONFIG_PCIEASPM_PERFORMANCE |
| static int aspm_policy = POLICY_PERFORMANCE; |
| #elif defined CONFIG_PCIEASPM_POWERSAVE |
| static int aspm_policy = POLICY_POWERSAVE; |
| #elif defined CONFIG_PCIEASPM_POWER_SUPERSAVE |
| static int aspm_policy = POLICY_POWER_SUPERSAVE; |
| #else |
| static int aspm_policy; |
| #endif |
| |
| static const char *policy_str[] = { |
| [POLICY_DEFAULT] = "default", |
| [POLICY_PERFORMANCE] = "performance", |
| [POLICY_POWERSAVE] = "powersave", |
| [POLICY_POWER_SUPERSAVE] = "powersupersave" |
| }; |
| |
| /* |
| * The L1 PM substate capability is only implemented in function 0 in a |
| * multi function device. |
| */ |
| static struct pci_dev *pci_function_0(struct pci_bus *linkbus) |
| { |
| struct pci_dev *child; |
| |
| list_for_each_entry(child, &linkbus->devices, bus_list) |
| if (PCI_FUNC(child->devfn) == 0) |
| return child; |
| return NULL; |
| } |
| |
| static int policy_to_aspm_state(struct pcie_link_state *link) |
| { |
| switch (aspm_policy) { |
| case POLICY_PERFORMANCE: |
| /* Disable ASPM and Clock PM */ |
| return 0; |
| case POLICY_POWERSAVE: |
| /* Enable ASPM L0s/L1 */ |
| return (ASPM_STATE_L0S | ASPM_STATE_L1); |
| case POLICY_POWER_SUPERSAVE: |
| /* Enable Everything */ |
| return ASPM_STATE_ALL; |
| case POLICY_DEFAULT: |
| return link->aspm_default; |
| } |
| return 0; |
| } |
| |
| static int policy_to_clkpm_state(struct pcie_link_state *link) |
| { |
| switch (aspm_policy) { |
| case POLICY_PERFORMANCE: |
| /* Disable ASPM and Clock PM */ |
| return 0; |
| case POLICY_POWERSAVE: |
| case POLICY_POWER_SUPERSAVE: |
| /* Enable Clock PM */ |
| return 1; |
| case POLICY_DEFAULT: |
| return link->clkpm_default; |
| } |
| return 0; |
| } |
| |
| static void pcie_set_clkpm_nocheck(struct pcie_link_state *link, int enable) |
| { |
| struct pci_dev *child; |
| struct pci_bus *linkbus = link->pdev->subordinate; |
| u32 val = enable ? PCI_EXP_LNKCTL_CLKREQ_EN : 0; |
| |
| list_for_each_entry(child, &linkbus->devices, bus_list) |
| pcie_capability_clear_and_set_word(child, PCI_EXP_LNKCTL, |
| PCI_EXP_LNKCTL_CLKREQ_EN, |
| val); |
| link->clkpm_enabled = !!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 |
| * 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) |
| return; |
| pcie_set_clkpm_nocheck(link, enable); |
| } |
| |
| static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist) |
| { |
| int capable = 1, enabled = 1; |
| u32 reg32; |
| u16 reg16; |
| struct pci_dev *child; |
| struct pci_bus *linkbus = link->pdev->subordinate; |
| |
| /* All functions should have the same cap and state, take the worst */ |
| list_for_each_entry(child, &linkbus->devices, bus_list) { |
| pcie_capability_read_dword(child, PCI_EXP_LNKCAP, ®32); |
| if (!(reg32 & PCI_EXP_LNKCAP_CLKPM)) { |
| capable = 0; |
| enabled = 0; |
| break; |
| } |
| pcie_capability_read_word(child, PCI_EXP_LNKCTL, ®16); |
| if (!(reg16 & PCI_EXP_LNKCTL_CLKREQ_EN)) |
| enabled = 0; |
| } |
| link->clkpm_enabled = enabled; |
| link->clkpm_default = enabled; |
| link->clkpm_capable = capable; |
| link->clkpm_disable = blacklist ? 1 : 0; |
| } |
| |
| /* |
| * pcie_aspm_configure_common_clock: check if the 2 ends of a link |
| * could use common clock. If they are, configure them to use the |
| * common clock. That will reduce the ASPM state exit latency. |
| */ |
| static void pcie_aspm_configure_common_clock(struct pcie_link_state *link) |
| { |
| int same_clock = 1; |
| u16 reg16, ccc, parent_old_ccc, child_old_ccc[8]; |
| struct pci_dev *child, *parent = link->pdev; |
| struct pci_bus *linkbus = parent->subordinate; |
| /* |
| * All functions of a slot should have the same Slot Clock |
| * Configuration, so just check one function |
| */ |
| child = list_entry(linkbus->devices.next, struct pci_dev, bus_list); |
| BUG_ON(!pci_is_pcie(child)); |
| |
| /* Check downstream component if bit Slot Clock Configuration is 1 */ |
| pcie_capability_read_word(child, PCI_EXP_LNKSTA, ®16); |
| if (!(reg16 & PCI_EXP_LNKSTA_SLC)) |
| same_clock = 0; |
| |
| /* Check upstream component if bit Slot Clock Configuration is 1 */ |
| pcie_capability_read_word(parent, PCI_EXP_LNKSTA, ®16); |
| if (!(reg16 & PCI_EXP_LNKSTA_SLC)) |
| same_clock = 0; |
| |
| /* Port might be already in common clock mode */ |
| pcie_capability_read_word(parent, PCI_EXP_LNKCTL, ®16); |
| parent_old_ccc = reg16 & PCI_EXP_LNKCTL_CCC; |
| if (same_clock && (reg16 & PCI_EXP_LNKCTL_CCC)) { |
| bool consistent = true; |
| |
| list_for_each_entry(child, &linkbus->devices, bus_list) { |
| pcie_capability_read_word(child, PCI_EXP_LNKCTL, |
| ®16); |
| if (!(reg16 & PCI_EXP_LNKCTL_CCC)) { |
| consistent = false; |
| break; |
| } |
| } |
| if (consistent) |
| return; |
| pci_info(parent, "ASPM: current common clock configuration is inconsistent, reconfiguring\n"); |
| } |
| |
| ccc = same_clock ? PCI_EXP_LNKCTL_CCC : 0; |
| /* Configure downstream component, all functions */ |
| list_for_each_entry(child, &linkbus->devices, bus_list) { |
| pcie_capability_read_word(child, PCI_EXP_LNKCTL, ®16); |
| child_old_ccc[PCI_FUNC(child->devfn)] = reg16 & PCI_EXP_LNKCTL_CCC; |
| pcie_capability_clear_and_set_word(child, PCI_EXP_LNKCTL, |
| PCI_EXP_LNKCTL_CCC, ccc); |
| } |
| |
| /* Configure upstream component */ |
| pcie_capability_clear_and_set_word(parent, PCI_EXP_LNKCTL, |
| PCI_EXP_LNKCTL_CCC, ccc); |
| |
| if (pcie_retrain_link(link->pdev, true)) { |
| |
| /* Training failed. Restore common clock configurations */ |
| pci_err(parent, "ASPM: Could not configure common clock\n"); |
| list_for_each_entry(child, &linkbus->devices, bus_list) |
| pcie_capability_clear_and_set_word(child, PCI_EXP_LNKCTL, |
| PCI_EXP_LNKCTL_CCC, |
| child_old_ccc[PCI_FUNC(child->devfn)]); |
| pcie_capability_clear_and_set_word(parent, PCI_EXP_LNKCTL, |
| PCI_EXP_LNKCTL_CCC, parent_old_ccc); |
| } |
| } |
| |
| /* Convert L0s latency encoding to ns */ |
| static u32 calc_l0s_latency(u32 lnkcap) |
| { |
| u32 encoding = FIELD_GET(PCI_EXP_LNKCAP_L0SEL, lnkcap); |
| |
| if (encoding == 0x7) |
| return 5 * NSEC_PER_USEC; /* > 4us */ |
| return (64 << encoding); |
| } |
| |
| /* Convert L0s acceptable latency encoding to ns */ |
| static u32 calc_l0s_acceptable(u32 encoding) |
| { |
| if (encoding == 0x7) |
| return U32_MAX; |
| return (64 << encoding); |
| } |
| |
| /* Convert L1 latency encoding to ns */ |
| static u32 calc_l1_latency(u32 lnkcap) |
| { |
| u32 encoding = FIELD_GET(PCI_EXP_LNKCAP_L1EL, lnkcap); |
| |
| if (encoding == 0x7) |
| return 65 * NSEC_PER_USEC; /* > 64us */ |
| return NSEC_PER_USEC << encoding; |
| } |
| |
| /* Convert L1 acceptable latency encoding to ns */ |
| static u32 calc_l1_acceptable(u32 encoding) |
| { |
| if (encoding == 0x7) |
| return U32_MAX; |
| return NSEC_PER_USEC << encoding; |
| } |
| |
| /* Convert L1SS T_pwr encoding to usec */ |
| static u32 calc_l12_pwron(struct pci_dev *pdev, u32 scale, u32 val) |
| { |
| switch (scale) { |
| case 0: |
| return val * 2; |
| case 1: |
| return val * 10; |
| case 2: |
| return val * 100; |
| } |
| pci_err(pdev, "%s: Invalid T_PwrOn scale: %u\n", __func__, scale); |
| return 0; |
| } |
| |
| /* |
| * Encode an LTR_L1.2_THRESHOLD value for the L1 PM Substates Control 1 |
| * register. Ports enter L1.2 when the most recent LTR value is greater |
| * than or equal to LTR_L1.2_THRESHOLD, so we round up to make sure we |
| * don't enter L1.2 too aggressively. |
| * |
| * See PCIe r6.0, sec 5.5.1, 6.18, 7.8.3.3. |
| */ |
| static void encode_l12_threshold(u32 threshold_us, u32 *scale, u32 *value) |
| { |
| u64 threshold_ns = (u64)threshold_us * NSEC_PER_USEC; |
| |
| /* |
| * LTR_L1.2_THRESHOLD_Value ("value") is a 10-bit field with max |
| * value of 0x3ff. |
| */ |
| if (threshold_ns <= 1 * FIELD_MAX(PCI_L1SS_CTL1_LTR_L12_TH_VALUE)) { |
| *scale = 0; /* Value times 1ns */ |
| *value = threshold_ns; |
| } else if (threshold_ns <= 32 * FIELD_MAX(PCI_L1SS_CTL1_LTR_L12_TH_VALUE)) { |
| *scale = 1; /* Value times 32ns */ |
| *value = roundup(threshold_ns, 32) / 32; |
| } else if (threshold_ns <= 1024 * FIELD_MAX(PCI_L1SS_CTL1_LTR_L12_TH_VALUE)) { |
| *scale = 2; /* Value times 1024ns */ |
| *value = roundup(threshold_ns, 1024) / 1024; |
| } else if (threshold_ns <= 32768 * FIELD_MAX(PCI_L1SS_CTL1_LTR_L12_TH_VALUE)) { |
| *scale = 3; /* Value times 32768ns */ |
| *value = roundup(threshold_ns, 32768) / 32768; |
| } else if (threshold_ns <= 1048576 * FIELD_MAX(PCI_L1SS_CTL1_LTR_L12_TH_VALUE)) { |
| *scale = 4; /* Value times 1048576ns */ |
| *value = roundup(threshold_ns, 1048576) / 1048576; |
| } else if (threshold_ns <= (u64)33554432 * FIELD_MAX(PCI_L1SS_CTL1_LTR_L12_TH_VALUE)) { |
| *scale = 5; /* Value times 33554432ns */ |
| *value = roundup(threshold_ns, 33554432) / 33554432; |
| } else { |
| *scale = 5; |
| *value = FIELD_MAX(PCI_L1SS_CTL1_LTR_L12_TH_VALUE); |
| } |
| } |
| |
| static void pcie_aspm_check_latency(struct pci_dev *endpoint) |
| { |
| u32 latency, encoding, lnkcap_up, lnkcap_dw; |
| u32 l1_switch_latency = 0, latency_up_l0s; |
| u32 latency_up_l1, latency_dw_l0s, latency_dw_l1; |
| u32 acceptable_l0s, acceptable_l1; |
| struct pcie_link_state *link; |
| |
| /* Device not in D0 doesn't need latency check */ |
| if ((endpoint->current_state != PCI_D0) && |
| (endpoint->current_state != PCI_UNKNOWN)) |
| return; |
| |
| link = endpoint->bus->self->link_state; |
| |
| /* Calculate endpoint L0s acceptable latency */ |
| encoding = FIELD_GET(PCI_EXP_DEVCAP_L0S, endpoint->devcap); |
| acceptable_l0s = calc_l0s_acceptable(encoding); |
| |
| /* Calculate endpoint L1 acceptable latency */ |
| encoding = FIELD_GET(PCI_EXP_DEVCAP_L1, endpoint->devcap); |
| acceptable_l1 = calc_l1_acceptable(encoding); |
| |
| while (link) { |
| struct pci_dev *dev = pci_function_0(link->pdev->subordinate); |
| |
| /* Read direction exit latencies */ |
| pcie_capability_read_dword(link->pdev, PCI_EXP_LNKCAP, |
| &lnkcap_up); |
| pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, |
| &lnkcap_dw); |
| latency_up_l0s = calc_l0s_latency(lnkcap_up); |
| latency_up_l1 = calc_l1_latency(lnkcap_up); |
| latency_dw_l0s = calc_l0s_latency(lnkcap_dw); |
| latency_dw_l1 = calc_l1_latency(lnkcap_dw); |
| |
| /* Check upstream direction L0s latency */ |
| if ((link->aspm_capable & ASPM_STATE_L0S_UP) && |
| (latency_up_l0s > acceptable_l0s)) |
| link->aspm_capable &= ~ASPM_STATE_L0S_UP; |
| |
| /* Check downstream direction L0s latency */ |
| if ((link->aspm_capable & ASPM_STATE_L0S_DW) && |
| (latency_dw_l0s > acceptable_l0s)) |
| link->aspm_capable &= ~ASPM_STATE_L0S_DW; |
| /* |
| * Check L1 latency. |
| * Every switch on the path to root complex need 1 |
| * more microsecond for L1. Spec doesn't mention L0s. |
| * |
| * The exit latencies for L1 substates are not advertised |
| * by a device. Since the spec also doesn't mention a way |
| * to determine max latencies introduced by enabling L1 |
| * substates on the components, it is not clear how to do |
| * a L1 substate exit latency check. We assume that the |
| * L1 exit latencies advertised by a device include L1 |
| * substate latencies (and hence do not do any check). |
| */ |
| latency = max_t(u32, latency_up_l1, latency_dw_l1); |
| if ((link->aspm_capable & ASPM_STATE_L1) && |
| (latency + l1_switch_latency > acceptable_l1)) |
| link->aspm_capable &= ~ASPM_STATE_L1; |
| l1_switch_latency += NSEC_PER_USEC; |
| |
| link = link->parent; |
| } |
| } |
| |
| /* Calculate L1.2 PM substate timing parameters */ |
| static void aspm_calc_l12_info(struct pcie_link_state *link, |
| u32 parent_l1ss_cap, u32 child_l1ss_cap) |
| { |
| struct pci_dev *child = link->downstream, *parent = link->pdev; |
| u32 val1, val2, scale1, scale2; |
| u32 t_common_mode, t_power_on, l1_2_threshold, scale, value; |
| u32 ctl1 = 0, ctl2 = 0; |
| u32 pctl1, pctl2, cctl1, cctl2; |
| u32 pl1_2_enables, cl1_2_enables; |
| |
| /* Choose the greater of the two Port Common_Mode_Restore_Times */ |
| val1 = FIELD_GET(PCI_L1SS_CAP_CM_RESTORE_TIME, parent_l1ss_cap); |
| val2 = FIELD_GET(PCI_L1SS_CAP_CM_RESTORE_TIME, child_l1ss_cap); |
| t_common_mode = max(val1, val2); |
| |
| /* Choose the greater of the two Port T_POWER_ON times */ |
| val1 = FIELD_GET(PCI_L1SS_CAP_P_PWR_ON_VALUE, parent_l1ss_cap); |
| scale1 = FIELD_GET(PCI_L1SS_CAP_P_PWR_ON_SCALE, parent_l1ss_cap); |
| val2 = FIELD_GET(PCI_L1SS_CAP_P_PWR_ON_VALUE, child_l1ss_cap); |
| scale2 = FIELD_GET(PCI_L1SS_CAP_P_PWR_ON_SCALE, child_l1ss_cap); |
| |
| if (calc_l12_pwron(parent, scale1, val1) > |
| calc_l12_pwron(child, scale2, val2)) { |
| ctl2 |= FIELD_PREP(PCI_L1SS_CTL2_T_PWR_ON_SCALE, scale1) | |
| FIELD_PREP(PCI_L1SS_CTL2_T_PWR_ON_VALUE, val1); |
| t_power_on = calc_l12_pwron(parent, scale1, val1); |
| } else { |
| ctl2 |= FIELD_PREP(PCI_L1SS_CTL2_T_PWR_ON_SCALE, scale2) | |
| FIELD_PREP(PCI_L1SS_CTL2_T_PWR_ON_VALUE, val2); |
| t_power_on = calc_l12_pwron(child, scale2, val2); |
| } |
| |
| /* |
| * Set LTR_L1.2_THRESHOLD to the time required to transition the |
| * Link from L0 to L1.2 and back to L0 so we enter L1.2 only if |
| * downstream devices report (via LTR) that they can tolerate at |
| * least that much latency. |
| * |
| * Based on PCIe r3.1, sec 5.5.3.3.1, Figures 5-16 and 5-17, and |
| * Table 5-11. T(POWER_OFF) is at most 2us and T(L1.2) is at |
| * least 4us. |
| */ |
| l1_2_threshold = 2 + 4 + t_common_mode + t_power_on; |
| encode_l12_threshold(l1_2_threshold, &scale, &value); |
| ctl1 |= FIELD_PREP(PCI_L1SS_CTL1_CM_RESTORE_TIME, t_common_mode) | |
| FIELD_PREP(PCI_L1SS_CTL1_LTR_L12_TH_VALUE, value) | |
| FIELD_PREP(PCI_L1SS_CTL1_LTR_L12_TH_SCALE, scale); |
| |
| /* Some broken devices only support dword access to L1 SS */ |
| pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1, &pctl1); |
| pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CTL2, &pctl2); |
| pci_read_config_dword(child, child->l1ss + PCI_L1SS_CTL1, &cctl1); |
| pci_read_config_dword(child, child->l1ss + PCI_L1SS_CTL2, &cctl2); |
| |
| if (ctl1 == pctl1 && ctl1 == cctl1 && |
| ctl2 == pctl2 && ctl2 == cctl2) |
| return; |
| |
| /* Disable L1.2 while updating. See PCIe r5.0, sec 5.5.4, 7.8.3.3 */ |
| pl1_2_enables = pctl1 & PCI_L1SS_CTL1_L1_2_MASK; |
| cl1_2_enables = cctl1 & PCI_L1SS_CTL1_L1_2_MASK; |
| |
| if (pl1_2_enables || cl1_2_enables) { |
| pci_clear_and_set_config_dword(child, |
| child->l1ss + PCI_L1SS_CTL1, |
| PCI_L1SS_CTL1_L1_2_MASK, 0); |
| pci_clear_and_set_config_dword(parent, |
| parent->l1ss + PCI_L1SS_CTL1, |
| PCI_L1SS_CTL1_L1_2_MASK, 0); |
| } |
| |
| /* Program T_POWER_ON times in both ports */ |
| pci_write_config_dword(parent, parent->l1ss + PCI_L1SS_CTL2, ctl2); |
| pci_write_config_dword(child, child->l1ss + PCI_L1SS_CTL2, ctl2); |
| |
| /* Program Common_Mode_Restore_Time in upstream device */ |
| pci_clear_and_set_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1, |
| PCI_L1SS_CTL1_CM_RESTORE_TIME, ctl1); |
| |
| /* Program LTR_L1.2_THRESHOLD time in both ports */ |
| pci_clear_and_set_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1, |
| PCI_L1SS_CTL1_LTR_L12_TH_VALUE | |
| PCI_L1SS_CTL1_LTR_L12_TH_SCALE, |
| ctl1); |
| pci_clear_and_set_config_dword(child, child->l1ss + PCI_L1SS_CTL1, |
| PCI_L1SS_CTL1_LTR_L12_TH_VALUE | |
| PCI_L1SS_CTL1_LTR_L12_TH_SCALE, |
| ctl1); |
| |
| if (pl1_2_enables || cl1_2_enables) { |
| pci_clear_and_set_config_dword(parent, |
| parent->l1ss + PCI_L1SS_CTL1, 0, |
| pl1_2_enables); |
| pci_clear_and_set_config_dword(child, |
| child->l1ss + PCI_L1SS_CTL1, 0, |
| cl1_2_enables); |
| } |
| } |
| |
| static void aspm_l1ss_init(struct pcie_link_state *link) |
| { |
| struct pci_dev *child = link->downstream, *parent = link->pdev; |
| u32 parent_l1ss_cap, child_l1ss_cap; |
| u32 parent_l1ss_ctl1 = 0, child_l1ss_ctl1 = 0; |
| |
| if (!parent->l1ss || !child->l1ss) |
| return; |
| |
| /* Setup L1 substate */ |
| pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CAP, |
| &parent_l1ss_cap); |
| pci_read_config_dword(child, child->l1ss + PCI_L1SS_CAP, |
| &child_l1ss_cap); |
| |
| if (!(parent_l1ss_cap & PCI_L1SS_CAP_L1_PM_SS)) |
| parent_l1ss_cap = 0; |
| if (!(child_l1ss_cap & PCI_L1SS_CAP_L1_PM_SS)) |
| child_l1ss_cap = 0; |
| |
| /* |
| * If we don't have LTR for the entire path from the Root Complex |
| * to this device, we can't use ASPM L1.2 because it relies on the |
| * LTR_L1.2_THRESHOLD. See PCIe r4.0, secs 5.5.4, 6.18. |
| */ |
| if (!child->ltr_path) |
| child_l1ss_cap &= ~PCI_L1SS_CAP_ASPM_L1_2; |
| |
| if (parent_l1ss_cap & child_l1ss_cap & PCI_L1SS_CAP_ASPM_L1_1) |
| link->aspm_support |= ASPM_STATE_L1_1; |
| if (parent_l1ss_cap & child_l1ss_cap & PCI_L1SS_CAP_ASPM_L1_2) |
| link->aspm_support |= ASPM_STATE_L1_2; |
| if (parent_l1ss_cap & child_l1ss_cap & PCI_L1SS_CAP_PCIPM_L1_1) |
| link->aspm_support |= ASPM_STATE_L1_1_PCIPM; |
| if (parent_l1ss_cap & child_l1ss_cap & PCI_L1SS_CAP_PCIPM_L1_2) |
| link->aspm_support |= ASPM_STATE_L1_2_PCIPM; |
| |
| if (parent_l1ss_cap) |
| pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1, |
| &parent_l1ss_ctl1); |
| if (child_l1ss_cap) |
| pci_read_config_dword(child, child->l1ss + PCI_L1SS_CTL1, |
| &child_l1ss_ctl1); |
| |
| if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_ASPM_L1_1) |
| link->aspm_enabled |= ASPM_STATE_L1_1; |
| if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_ASPM_L1_2) |
| link->aspm_enabled |= ASPM_STATE_L1_2; |
| if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_PCIPM_L1_1) |
| link->aspm_enabled |= ASPM_STATE_L1_1_PCIPM; |
| if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_PCIPM_L1_2) |
| link->aspm_enabled |= ASPM_STATE_L1_2_PCIPM; |
| |
| if (link->aspm_support & ASPM_STATE_L1_2_MASK) |
| aspm_calc_l12_info(link, parent_l1ss_cap, child_l1ss_cap); |
| } |
| |
| static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) |
| { |
| struct pci_dev *child = link->downstream, *parent = link->pdev; |
| u32 parent_lnkcap, child_lnkcap; |
| u16 parent_lnkctl, child_lnkctl; |
| struct pci_bus *linkbus = parent->subordinate; |
| |
| if (blacklist) { |
| /* Set enabled/disable so that we will disable ASPM later */ |
| link->aspm_enabled = ASPM_STATE_ALL; |
| link->aspm_disable = ASPM_STATE_ALL; |
| return; |
| } |
| |
| /* |
| * If ASPM not supported, don't mess with the clocks and link, |
| * bail out now. |
| */ |
| pcie_capability_read_dword(parent, PCI_EXP_LNKCAP, &parent_lnkcap); |
| pcie_capability_read_dword(child, PCI_EXP_LNKCAP, &child_lnkcap); |
| if (!(parent_lnkcap & child_lnkcap & PCI_EXP_LNKCAP_ASPMS)) |
| return; |
| |
| /* Configure common clock before checking latencies */ |
| pcie_aspm_configure_common_clock(link); |
| |
| /* |
| * Re-read upstream/downstream components' register state after |
| * clock configuration. L0s & L1 exit latencies in the otherwise |
| * read-only Link Capabilities may change depending on common clock |
| * configuration (PCIe r5.0, sec 7.5.3.6). |
| */ |
| pcie_capability_read_dword(parent, PCI_EXP_LNKCAP, &parent_lnkcap); |
| pcie_capability_read_dword(child, PCI_EXP_LNKCAP, &child_lnkcap); |
| pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &parent_lnkctl); |
| pcie_capability_read_word(child, PCI_EXP_LNKCTL, &child_lnkctl); |
| |
| /* |
| * Setup L0s state |
| * |
| * Note that we must not enable L0s in either direction on a |
| * given link unless components on both sides of the link each |
| * support L0s. |
| */ |
| if (parent_lnkcap & child_lnkcap & PCI_EXP_LNKCAP_ASPM_L0S) |
| link->aspm_support |= ASPM_STATE_L0S; |
| |
| if (child_lnkctl & PCI_EXP_LNKCTL_ASPM_L0S) |
| link->aspm_enabled |= ASPM_STATE_L0S_UP; |
| if (parent_lnkctl & PCI_EXP_LNKCTL_ASPM_L0S) |
| link->aspm_enabled |= ASPM_STATE_L0S_DW; |
| |
| /* Setup L1 state */ |
| if (parent_lnkcap & child_lnkcap & PCI_EXP_LNKCAP_ASPM_L1) |
| link->aspm_support |= ASPM_STATE_L1; |
| |
| if (parent_lnkctl & child_lnkctl & PCI_EXP_LNKCTL_ASPM_L1) |
| link->aspm_enabled |= ASPM_STATE_L1; |
| |
| aspm_l1ss_init(link); |
| |
| /* Save default state */ |
| link->aspm_default = link->aspm_enabled; |
| |
| /* Setup initial capable state. Will be updated later */ |
| link->aspm_capable = link->aspm_support; |
| |
| /* Get and check endpoint acceptable latencies */ |
| list_for_each_entry(child, &linkbus->devices, bus_list) { |
| if (pci_pcie_type(child) != PCI_EXP_TYPE_ENDPOINT && |
| pci_pcie_type(child) != PCI_EXP_TYPE_LEG_END) |
| continue; |
| |
| pcie_aspm_check_latency(child); |
| } |
| } |
| |
| /* Configure the ASPM L1 substates */ |
| static void pcie_config_aspm_l1ss(struct pcie_link_state *link, u32 state) |
| { |
| u32 val, enable_req; |
| struct pci_dev *child = link->downstream, *parent = link->pdev; |
| |
| enable_req = (link->aspm_enabled ^ state) & state; |
| |
| /* |
| * Here are the rules specified in the PCIe spec for enabling L1SS: |
| * - When enabling L1.x, enable bit at parent first, then at child |
| * - When disabling L1.x, disable bit at child first, then at parent |
| * - When enabling ASPM L1.x, need to disable L1 |
| * (at child followed by parent). |
| * - The ASPM/PCIPM L1.2 must be disabled while programming timing |
| * parameters |
| * |
| * To keep it simple, disable all L1SS bits first, and later enable |
| * what is needed. |
| */ |
| |
| /* Disable all L1 substates */ |
| pci_clear_and_set_config_dword(child, child->l1ss + PCI_L1SS_CTL1, |
| PCI_L1SS_CTL1_L1SS_MASK, 0); |
| pci_clear_and_set_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1, |
| PCI_L1SS_CTL1_L1SS_MASK, 0); |
| /* |
| * If needed, disable L1, and it gets enabled later |
| * in pcie_config_aspm_link(). |
| */ |
| if (enable_req & (ASPM_STATE_L1_1 | ASPM_STATE_L1_2)) { |
| pcie_capability_clear_word(child, PCI_EXP_LNKCTL, |
| PCI_EXP_LNKCTL_ASPM_L1); |
| pcie_capability_clear_word(parent, PCI_EXP_LNKCTL, |
| PCI_EXP_LNKCTL_ASPM_L1); |
| } |
| |
| val = 0; |
| if (state & ASPM_STATE_L1_1) |
| val |= PCI_L1SS_CTL1_ASPM_L1_1; |
| if (state & ASPM_STATE_L1_2) |
| val |= PCI_L1SS_CTL1_ASPM_L1_2; |
| if (state & ASPM_STATE_L1_1_PCIPM) |
| val |= PCI_L1SS_CTL1_PCIPM_L1_1; |
| if (state & ASPM_STATE_L1_2_PCIPM) |
| val |= PCI_L1SS_CTL1_PCIPM_L1_2; |
| |
| /* Enable what we need to enable */ |
| pci_clear_and_set_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1, |
| PCI_L1SS_CTL1_L1SS_MASK, val); |
| pci_clear_and_set_config_dword(child, child->l1ss + PCI_L1SS_CTL1, |
| PCI_L1SS_CTL1_L1SS_MASK, val); |
| } |
| |
| static void pcie_config_aspm_dev(struct pci_dev *pdev, u32 val) |
| { |
| pcie_capability_clear_and_set_word(pdev, PCI_EXP_LNKCTL, |
| PCI_EXP_LNKCTL_ASPMC, val); |
| } |
| |
| static void pcie_config_aspm_link(struct pcie_link_state *link, u32 state) |
| { |
| u32 upstream = 0, dwstream = 0; |
| struct pci_dev *child = link->downstream, *parent = link->pdev; |
| struct pci_bus *linkbus = parent->subordinate; |
| |
| /* Enable only the states that were not explicitly disabled */ |
| state &= (link->aspm_capable & ~link->aspm_disable); |
| |
| /* Can't enable any substates if L1 is not enabled */ |
| if (!(state & ASPM_STATE_L1)) |
| state &= ~ASPM_STATE_L1SS; |
| |
| /* Spec says both ports must be in D0 before enabling PCI PM substates*/ |
| if (parent->current_state != PCI_D0 || child->current_state != PCI_D0) { |
| state &= ~ASPM_STATE_L1_SS_PCIPM; |
| state |= (link->aspm_enabled & ASPM_STATE_L1_SS_PCIPM); |
| } |
| |
| /* Nothing to do if the link is already in the requested state */ |
| if (link->aspm_enabled == state) |
| return; |
| /* Convert ASPM state to upstream/downstream ASPM register state */ |
| if (state & ASPM_STATE_L0S_UP) |
| dwstream |= PCI_EXP_LNKCTL_ASPM_L0S; |
| if (state & ASPM_STATE_L0S_DW) |
| upstream |= PCI_EXP_LNKCTL_ASPM_L0S; |
| if (state & ASPM_STATE_L1) { |
| upstream |= PCI_EXP_LNKCTL_ASPM_L1; |
| dwstream |= PCI_EXP_LNKCTL_ASPM_L1; |
| } |
| |
| if (link->aspm_capable & ASPM_STATE_L1SS) |
| pcie_config_aspm_l1ss(link, state); |
| |
| /* |
| * Spec 2.0 suggests all functions should be configured the |
| * same setting for ASPM. Enabling ASPM L1 should be done in |
| * upstream component first and then downstream, and vice |
| * versa for disabling ASPM L1. Spec doesn't mention L0S. |
| */ |
| if (state & ASPM_STATE_L1) |
| pcie_config_aspm_dev(parent, upstream); |
| list_for_each_entry(child, &linkbus->devices, bus_list) |
| pcie_config_aspm_dev(child, dwstream); |
| if (!(state & ASPM_STATE_L1)) |
| pcie_config_aspm_dev(parent, upstream); |
| |
| link->aspm_enabled = state; |
| } |
| |
| static void pcie_config_aspm_path(struct pcie_link_state *link) |
| { |
| while (link) { |
| pcie_config_aspm_link(link, policy_to_aspm_state(link)); |
| link = link->parent; |
| } |
| } |
| |
| static void free_link_state(struct pcie_link_state *link) |
| { |
| link->pdev->link_state = NULL; |
| kfree(link); |
| } |
| |
| static int pcie_aspm_sanity_check(struct pci_dev *pdev) |
| { |
| struct pci_dev *child; |
| u32 reg32; |
| |
| /* |
| * Some functions in a slot might not all be PCIe functions, |
| * very strange. Disable ASPM for the whole slot |
| */ |
| list_for_each_entry(child, &pdev->subordinate->devices, bus_list) { |
| if (!pci_is_pcie(child)) |
| return -EINVAL; |
| |
| /* |
| * If ASPM is disabled then we're not going to change |
| * the BIOS state. It's safe to continue even if it's a |
| * pre-1.1 device |
| */ |
| |
| if (aspm_disabled) |
| continue; |
| |
| /* |
| * Disable ASPM for pre-1.1 PCIe device, we follow MS to use |
| * RBER bit to determine if a function is 1.1 version device |
| */ |
| pcie_capability_read_dword(child, PCI_EXP_DEVCAP, ®32); |
| if (!(reg32 & PCI_EXP_DEVCAP_RBER) && !aspm_force) { |
| pci_info(child, "disabling ASPM on pre-1.1 PCIe device. You can enable it with 'pcie_aspm=force'\n"); |
| return -EINVAL; |
| } |
| } |
| return 0; |
| } |
| |
| static struct pcie_link_state *alloc_pcie_link_state(struct pci_dev *pdev) |
| { |
| struct pcie_link_state *link; |
| |
| link = kzalloc(sizeof(*link), GFP_KERNEL); |
| if (!link) |
| return NULL; |
| |
| INIT_LIST_HEAD(&link->sibling); |
| link->pdev = pdev; |
| link->downstream = pci_function_0(pdev->subordinate); |
| |
| /* |
| * Root Ports and PCI/PCI-X to PCIe Bridges are roots of PCIe |
| * hierarchies. Note that some PCIe host implementations omit |
| * the root ports entirely, in which case a downstream port on |
| * a switch may become the root of the link state chain for all |
| * its subordinate endpoints. |
| */ |
| if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT || |
| pci_pcie_type(pdev) == PCI_EXP_TYPE_PCIE_BRIDGE || |
| !pdev->bus->parent->self) { |
| link->root = link; |
| } else { |
| struct pcie_link_state *parent; |
| |
| parent = pdev->bus->parent->self->link_state; |
| if (!parent) { |
| kfree(link); |
| return NULL; |
| } |
| |
| link->parent = parent; |
| link->root = link->parent->root; |
| } |
| |
| list_add(&link->sibling, &link_list); |
| pdev->link_state = link; |
| 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. |
| * @pdev: the root port or switch downstream port |
| */ |
| void pcie_aspm_init_link_state(struct pci_dev *pdev) |
| { |
| struct pcie_link_state *link; |
| int blacklist = !!pcie_aspm_sanity_check(pdev); |
| |
| if (!aspm_support_enabled) |
| return; |
| |
| if (pdev->link_state) |
| return; |
| |
| /* |
| * We allocate pcie_link_state for the component on the upstream |
| * end of a Link, so there's nothing to do unless this device is |
| * downstream port. |
| */ |
| if (!pcie_downstream_port(pdev)) |
| return; |
| |
| /* VIA has a strange chipset, root port is under a bridge */ |
| if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT && |
| pdev->bus->self) |
| return; |
| |
| down_read(&pci_bus_sem); |
| if (list_empty(&pdev->subordinate->devices)) |
| goto out; |
| |
| mutex_lock(&aspm_lock); |
| link = alloc_pcie_link_state(pdev); |
| if (!link) |
| goto unlock; |
| /* |
| * Setup initial ASPM state. Note that we need to configure |
| * upstream links also because capable state of them can be |
| * update through pcie_aspm_cap_init(). |
| */ |
| pcie_aspm_cap_init(link, blacklist); |
| |
| /* Setup initial Clock PM state */ |
| pcie_clkpm_cap_init(link, blacklist); |
| |
| /* |
| * At this stage drivers haven't had an opportunity to change the |
| * link policy setting. Enabling ASPM on broken hardware can cripple |
| * it even before the driver has had a chance to disable ASPM, so |
| * default to a safe level right now. If we're enabling ASPM beyond |
| * the BIOS's expectation, we'll do so once pci_enable_device() is |
| * called. |
| */ |
| if (aspm_policy != POLICY_POWERSAVE && |
| aspm_policy != POLICY_POWER_SUPERSAVE) { |
| pcie_config_aspm_path(link); |
| pcie_set_clkpm(link, policy_to_clkpm_state(link)); |
| } |
| |
| pcie_aspm_update_sysfs_visibility(pdev); |
| |
| unlock: |
| mutex_unlock(&aspm_lock); |
| out: |
| up_read(&pci_bus_sem); |
| } |
| |
| /* Recheck latencies and update aspm_capable for links under the root */ |
| static void pcie_update_aspm_capable(struct pcie_link_state *root) |
| { |
| struct pcie_link_state *link; |
| BUG_ON(root->parent); |
| list_for_each_entry(link, &link_list, sibling) { |
| if (link->root != root) |
| continue; |
| link->aspm_capable = link->aspm_support; |
| } |
| list_for_each_entry(link, &link_list, sibling) { |
| struct pci_dev *child; |
| struct pci_bus *linkbus = link->pdev->subordinate; |
| if (link->root != root) |
| continue; |
| list_for_each_entry(child, &linkbus->devices, bus_list) { |
| if ((pci_pcie_type(child) != PCI_EXP_TYPE_ENDPOINT) && |
| (pci_pcie_type(child) != PCI_EXP_TYPE_LEG_END)) |
| continue; |
| pcie_aspm_check_latency(child); |
| } |
| } |
| } |
| |
| /* @pdev: the endpoint device */ |
| void pcie_aspm_exit_link_state(struct pci_dev *pdev) |
| { |
| struct pci_dev *parent = pdev->bus->self; |
| struct pcie_link_state *link, *root, *parent_link; |
| |
| if (!parent || !parent->link_state) |
| return; |
| |
| down_read(&pci_bus_sem); |
| mutex_lock(&aspm_lock); |
| |
| link = parent->link_state; |
| root = link->root; |
| parent_link = link->parent; |
| |
| /* |
| * link->downstream is a pointer to the pci_dev of function 0. If |
| * we remove that function, the pci_dev is about to be deallocated, |
| * so we can't use link->downstream again. Free the link state to |
| * avoid this. |
| * |
| * If we're removing a non-0 function, it's possible we could |
| * retain the link state, but PCIe r6.0, sec 7.5.3.7, recommends |
| * programming the same ASPM Control value for all functions of |
| * multi-function devices, so disable ASPM for all of them. |
| */ |
| pcie_config_aspm_link(link, 0); |
| list_del(&link->sibling); |
| free_link_state(link); |
| |
| /* Recheck latencies and configure upstream links */ |
| if (parent_link) { |
| pcie_update_aspm_capable(root); |
| pcie_config_aspm_path(parent_link); |
| } |
| |
| mutex_unlock(&aspm_lock); |
| up_read(&pci_bus_sem); |
| } |
| |
| /* |
| * @pdev: the root port or switch downstream port |
| * @locked: whether pci_bus_sem is held |
| */ |
| void pcie_aspm_pm_state_change(struct pci_dev *pdev, bool locked) |
| { |
| struct pcie_link_state *link = pdev->link_state; |
| |
| if (aspm_disabled || !link) |
| return; |
| /* |
| * Devices changed PM state, we should recheck if latency |
| * meets all functions' requirement |
| */ |
| if (!locked) |
| down_read(&pci_bus_sem); |
| mutex_lock(&aspm_lock); |
| pcie_update_aspm_capable(link->root); |
| pcie_config_aspm_path(link); |
| mutex_unlock(&aspm_lock); |
| if (!locked) |
| up_read(&pci_bus_sem); |
| } |
| |
| void pcie_aspm_powersave_config_link(struct pci_dev *pdev) |
| { |
| struct pcie_link_state *link = pdev->link_state; |
| |
| if (aspm_disabled || !link) |
| return; |
| |
| if (aspm_policy != POLICY_POWERSAVE && |
| aspm_policy != POLICY_POWER_SUPERSAVE) |
| return; |
| |
| down_read(&pci_bus_sem); |
| mutex_lock(&aspm_lock); |
| pcie_config_aspm_path(link); |
| pcie_set_clkpm(link, policy_to_clkpm_state(link)); |
| mutex_unlock(&aspm_lock); |
| up_read(&pci_bus_sem); |
| } |
| |
| static struct pcie_link_state *pcie_aspm_get_link(struct pci_dev *pdev) |
| { |
| struct pci_dev *bridge; |
| |
| if (!pci_is_pcie(pdev)) |
| return NULL; |
| |
| 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 locked) |
| { |
| 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 |
| * systems we have to observe the FADT ACPI_FADT_NO_ASPM bit and |
| * the _OSC method), we can't honor that request. Windows has |
| * a similar mechanism using "PciASPMOptOut", which is also |
| * ignored in this situation. |
| */ |
| if (aspm_disabled) { |
| pci_warn(pdev, "can't disable ASPM; OS doesn't have ASPM control\n"); |
| return -EPERM; |
| } |
| |
| if (!locked) |
| down_read(&pci_bus_sem); |
| mutex_lock(&aspm_lock); |
| if (state & PCIE_LINK_STATE_L0S) |
| link->aspm_disable |= ASPM_STATE_L0S; |
| if (state & PCIE_LINK_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_disable = 1; |
| pcie_set_clkpm(link, policy_to_clkpm_state(link)); |
| mutex_unlock(&aspm_lock); |
| if (!locked) |
| up_read(&pci_bus_sem); |
| |
| return 0; |
| } |
| |
| int pci_disable_link_state_locked(struct pci_dev *pdev, int state) |
| { |
| lockdep_assert_held_read(&pci_bus_sem); |
| |
| return __pci_disable_link_state(pdev, state, true); |
| } |
| EXPORT_SYMBOL(pci_disable_link_state_locked); |
| |
| /** |
| * pci_disable_link_state - Disable device's link state, so the link will |
| * never enter specific states. Note that if the BIOS didn't grant ASPM |
| * control to the OS, this does nothing because we can't touch the LNKCTL |
| * register. Returns 0 or a negative errno. |
| * |
| * @pdev: PCI device |
| * @state: ASPM link state to disable |
| */ |
| int pci_disable_link_state(struct pci_dev *pdev, int state) |
| { |
| return __pci_disable_link_state(pdev, state, false); |
| } |
| EXPORT_SYMBOL(pci_disable_link_state); |
| |
| static int __pci_enable_link_state(struct pci_dev *pdev, int state, bool locked) |
| { |
| struct pcie_link_state *link = pcie_aspm_get_link(pdev); |
| |
| if (!link) |
| return -EINVAL; |
| /* |
| * A driver requested that ASPM be enabled on this device, but |
| * if we don't have permission to manage ASPM (e.g., on ACPI |
| * systems we have to observe the FADT ACPI_FADT_NO_ASPM bit and |
| * the _OSC method), we can't honor that request. |
| */ |
| if (aspm_disabled) { |
| pci_warn(pdev, "can't override BIOS ASPM; OS doesn't have ASPM control\n"); |
| return -EPERM; |
| } |
| |
| if (!locked) |
| down_read(&pci_bus_sem); |
| mutex_lock(&aspm_lock); |
| link->aspm_default = 0; |
| if (state & PCIE_LINK_STATE_L0S) |
| link->aspm_default |= ASPM_STATE_L0S; |
| if (state & PCIE_LINK_STATE_L1) |
| link->aspm_default |= ASPM_STATE_L1; |
| /* L1 PM substates require L1 */ |
| if (state & PCIE_LINK_STATE_L1_1) |
| link->aspm_default |= ASPM_STATE_L1_1 | ASPM_STATE_L1; |
| if (state & PCIE_LINK_STATE_L1_2) |
| link->aspm_default |= ASPM_STATE_L1_2 | ASPM_STATE_L1; |
| if (state & PCIE_LINK_STATE_L1_1_PCIPM) |
| link->aspm_default |= ASPM_STATE_L1_1_PCIPM | ASPM_STATE_L1; |
| if (state & PCIE_LINK_STATE_L1_2_PCIPM) |
| link->aspm_default |= ASPM_STATE_L1_2_PCIPM | ASPM_STATE_L1; |
| pcie_config_aspm_link(link, policy_to_aspm_state(link)); |
| |
| link->clkpm_default = (state & PCIE_LINK_STATE_CLKPM) ? 1 : 0; |
| pcie_set_clkpm(link, policy_to_clkpm_state(link)); |
| mutex_unlock(&aspm_lock); |
| if (!locked) |
| up_read(&pci_bus_sem); |
| |
| return 0; |
| } |
| |
| /** |
| * pci_enable_link_state - Clear and set the default device link state so that |
| * the link may be allowed to enter the specified states. Note that if the |
| * BIOS didn't grant ASPM control to the OS, this does nothing because we can't |
| * touch the LNKCTL register. Also note that this does not enable states |
| * disabled by pci_disable_link_state(). Return 0 or a negative errno. |
| * |
| * @pdev: PCI device |
| * @state: Mask of ASPM link states to enable |
| */ |
| int pci_enable_link_state(struct pci_dev *pdev, int state) |
| { |
| return __pci_enable_link_state(pdev, state, false); |
| } |
| EXPORT_SYMBOL(pci_enable_link_state); |
| |
| /** |
| * pci_enable_link_state_locked - Clear and set the default device link state |
| * so that the link may be allowed to enter the specified states. Note that if |
| * the BIOS didn't grant ASPM control to the OS, this does nothing because we |
| * can't touch the LNKCTL register. Also note that this does not enable states |
| * disabled by pci_disable_link_state(). Return 0 or a negative errno. |
| * |
| * @pdev: PCI device |
| * @state: Mask of ASPM link states to enable |
| * |
| * Context: Caller holds pci_bus_sem read lock. |
| */ |
| int pci_enable_link_state_locked(struct pci_dev *pdev, int state) |
| { |
| lockdep_assert_held_read(&pci_bus_sem); |
| |
| return __pci_enable_link_state(pdev, state, true); |
| } |
| EXPORT_SYMBOL(pci_enable_link_state_locked); |
| |
| static int pcie_aspm_set_policy(const char *val, |
| const struct kernel_param *kp) |
| { |
| int i; |
| struct pcie_link_state *link; |
| |
| if (aspm_disabled) |
| return -EPERM; |
| i = sysfs_match_string(policy_str, val); |
| if (i < 0) |
| return i; |
| if (i == aspm_policy) |
| return 0; |
| |
| down_read(&pci_bus_sem); |
| mutex_lock(&aspm_lock); |
| aspm_policy = i; |
| list_for_each_entry(link, &link_list, sibling) { |
| pcie_config_aspm_link(link, policy_to_aspm_state(link)); |
| pcie_set_clkpm(link, policy_to_clkpm_state(link)); |
| } |
| mutex_unlock(&aspm_lock); |
| up_read(&pci_bus_sem); |
| return 0; |
| } |
| |
| static int pcie_aspm_get_policy(char *buffer, const struct kernel_param *kp) |
| { |
| int i, cnt = 0; |
| for (i = 0; i < ARRAY_SIZE(policy_str); i++) |
| if (i == aspm_policy) |
| cnt += sprintf(buffer + cnt, "[%s] ", policy_str[i]); |
| else |
| cnt += sprintf(buffer + cnt, "%s ", policy_str[i]); |
| cnt += sprintf(buffer + cnt, "\n"); |
| return cnt; |
| } |
| |
| module_param_call(policy, pcie_aspm_set_policy, pcie_aspm_get_policy, |
| NULL, 0644); |
| |
| /** |
| * 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 pcie_link_state *link = pcie_aspm_get_link(pdev); |
| |
| if (!link) |
| return false; |
| |
| return link->aspm_enabled; |
| } |
| EXPORT_SYMBOL_GPL(pcie_aspm_enabled); |
| |
| 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 sysfs_emit(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 (kstrtobool(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; |
| if (state & ASPM_STATE_L1) |
| link->aspm_disable |= ASPM_STATE_L1SS; |
| } |
| |
| 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 sysfs_emit(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 (kstrtobool(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")) { |
| aspm_policy = POLICY_DEFAULT; |
| aspm_disabled = 1; |
| aspm_support_enabled = false; |
| pr_info("PCIe ASPM is disabled\n"); |
| } else if (!strcmp(str, "force")) { |
| aspm_force = 1; |
| pr_info("PCIe ASPM is forcibly enabled\n"); |
| } |
| return 1; |
| } |
| |
| __setup("pcie_aspm=", pcie_aspm_disable); |
| |
| void pcie_no_aspm(void) |
| { |
| /* |
| * Disabling ASPM is intended to prevent the kernel from modifying |
| * existing hardware state, not to clear existing state. To that end: |
| * (a) set policy to POLICY_DEFAULT in order to avoid changing state |
| * (b) prevent userspace from changing policy |
| */ |
| if (!aspm_force) { |
| aspm_policy = POLICY_DEFAULT; |
| aspm_disabled = 1; |
| } |
| } |
| |
| bool pcie_aspm_support_enabled(void) |
| { |
| return aspm_support_enabled; |
| } |