diff options
Diffstat (limited to 'drivers/pci/pcie')
-rw-r--r-- | drivers/pci/pcie/aspm.c | 170 |
1 files changed, 107 insertions, 63 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 08d293f60fe..f289ca9bf18 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -26,6 +26,13 @@ #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_L0S (ASPM_STATE_L0S_UP | ASPM_STATE_L0S_DW) +#define ASPM_STATE_ALL (ASPM_STATE_L0S | ASPM_STATE_L1) + struct aspm_latency { u32 l0s; /* L0s latency (nsec) */ u32 l1; /* L1 latency (nsec) */ @@ -40,19 +47,20 @@ struct pcie_link_state { struct list_head link; /* node in parent's children list */ /* ASPM state */ - u32 aspm_support:2; /* Supported ASPM state */ - u32 aspm_enabled:2; /* Enabled ASPM state */ - u32 aspm_capable:2; /* Capable ASPM state with latency */ - u32 aspm_default:2; /* Default ASPM state by BIOS */ - u32 aspm_disable:2; /* Disabled ASPM state */ + u32 aspm_support:3; /* Supported ASPM state */ + u32 aspm_enabled:3; /* Enabled ASPM state */ + u32 aspm_capable:3; /* Capable ASPM state with latency */ + u32 aspm_default:3; /* Default ASPM state by BIOS */ + u32 aspm_disable:3; /* 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 */ - /* Latencies */ - struct aspm_latency latency; /* Exit latency */ + /* Exit latencies */ + struct aspm_latency latency_up; /* Upstream direction exit latency */ + struct aspm_latency latency_dw; /* Downstream direction exit latency */ /* * Endpoint acceptable latencies. A pcie downstream port only * has one slot under it, so at most there are 8 functions. @@ -84,7 +92,7 @@ static int policy_to_aspm_state(struct pcie_link_state *link) return 0; case POLICY_POWERSAVE: /* Enable ASPM L0s/L1 */ - return PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1; + return ASPM_STATE_ALL; case POLICY_DEFAULT: return link->aspm_default; } @@ -278,36 +286,35 @@ static u32 calc_l1_acceptable(u32 encoding) return (1000 << encoding); } -static void pcie_aspm_get_cap_device(struct pci_dev *pdev, u32 *state, - u32 *l0s, u32 *l1, u32 *enabled) +struct aspm_register_info { + u32 support:2; + u32 enabled:2; + u32 latency_encoding_l0s; + u32 latency_encoding_l1; +}; + +static void pcie_get_aspm_reg(struct pci_dev *pdev, + struct aspm_register_info *info) { int pos; u16 reg16; - u32 reg32, encoding; + u32 reg32; - *l0s = *l1 = *enabled = 0; pos = pci_find_capability(pdev, PCI_CAP_ID_EXP); pci_read_config_dword(pdev, pos + PCI_EXP_LNKCAP, ®32); - *state = (reg32 & PCI_EXP_LNKCAP_ASPMS) >> 10; - if (*state != PCIE_LINK_STATE_L0S && - *state != (PCIE_LINK_STATE_L1 | PCIE_LINK_STATE_L0S)) - *state = 0; - if (*state == 0) - return; - - encoding = (reg32 & PCI_EXP_LNKCAP_L0SEL) >> 12; - *l0s = calc_l0s_latency(encoding); - if (*state & PCIE_LINK_STATE_L1) { - encoding = (reg32 & PCI_EXP_LNKCAP_L1EL) >> 15; - *l1 = calc_l1_latency(encoding); - } + info->support = (reg32 & PCI_EXP_LNKCAP_ASPMS) >> 10; + /* 00b and 10b are defined as "Reserved". */ + if (info->support == PCIE_LINK_STATE_L1) + info->support = 0; + info->latency_encoding_l0s = (reg32 & PCI_EXP_LNKCAP_L0SEL) >> 12; + info->latency_encoding_l1 = (reg32 & PCI_EXP_LNKCAP_L1EL) >> 15; pci_read_config_word(pdev, pos + PCI_EXP_LNKCTL, ®16); - *enabled = reg16 & (PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1); + info->enabled = reg16 & PCI_EXP_LNKCTL_ASPMC; } static void pcie_aspm_check_latency(struct pci_dev *endpoint) { - u32 l1_switch_latency = 0; + u32 latency, l1_switch_latency = 0; struct aspm_latency *acceptable; struct pcie_link_state *link; @@ -320,18 +327,24 @@ static void pcie_aspm_check_latency(struct pci_dev *endpoint) acceptable = &link->acceptable[PCI_FUNC(endpoint->devfn)]; while (link) { - /* Check L0s latency */ - if ((link->aspm_capable & PCIE_LINK_STATE_L0S) && - (link->latency.l0s > acceptable->l0s)) - link->aspm_capable &= ~PCIE_LINK_STATE_L0S; + /* Check upstream direction L0s latency */ + if ((link->aspm_capable & ASPM_STATE_L0S_UP) && + (link->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) && + (link->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. */ - if ((link->aspm_capable & PCIE_LINK_STATE_L1) && - (link->latency.l1 + l1_switch_latency > acceptable->l1)) - link->aspm_capable &= ~PCIE_LINK_STATE_L1; + latency = max_t(u32, link->latency_up.l1, link->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 += 1000; link = link->parent; @@ -340,33 +353,48 @@ static void pcie_aspm_check_latency(struct pci_dev *endpoint) static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) { - u32 support, l0s, l1, enabled; struct pci_dev *child, *parent = link->pdev; struct pci_bus *linkbus = parent->subordinate; + struct aspm_register_info upreg, dwreg; if (blacklist) { /* Set enabled/disable so that we will disable ASPM later */ - link->aspm_enabled = PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1; - link->aspm_disable = PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1; + link->aspm_enabled = ASPM_STATE_ALL; + link->aspm_disable = ASPM_STATE_ALL; return; } /* Configure common clock before checking latencies */ pcie_aspm_configure_common_clock(link); - /* upstream component states */ - pcie_aspm_get_cap_device(parent, &support, &l0s, &l1, &enabled); - link->aspm_support = support; - link->latency.l0s = l0s; - link->latency.l1 = l1; - link->aspm_enabled = enabled; - - /* downstream component states, all functions have the same setting */ + /* Get upstream/downstream components' register state */ + pcie_get_aspm_reg(parent, &upreg); child = list_entry(linkbus->devices.next, struct pci_dev, bus_list); - pcie_aspm_get_cap_device(child, &support, &l0s, &l1, &enabled); - link->aspm_support &= support; - link->latency.l0s = max_t(u32, link->latency.l0s, l0s); - link->latency.l1 = max_t(u32, link->latency.l1, l1); + pcie_get_aspm_reg(child, &dwreg); + + /* + * 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 (dwreg.support & upreg.support & PCIE_LINK_STATE_L0S) + link->aspm_support |= ASPM_STATE_L0S; + if (dwreg.enabled & PCIE_LINK_STATE_L0S) + link->aspm_enabled |= ASPM_STATE_L0S_UP; + if (upreg.enabled & PCIE_LINK_STATE_L0S) + link->aspm_enabled |= ASPM_STATE_L0S_DW; + link->latency_up.l0s = calc_l0s_latency(upreg.latency_encoding_l0s); + link->latency_dw.l0s = calc_l0s_latency(dwreg.latency_encoding_l0s); + + /* Setup L1 state */ + if (upreg.support & dwreg.support & PCIE_LINK_STATE_L1) + link->aspm_support |= ASPM_STATE_L1; + if (upreg.enabled & dwreg.enabled & PCIE_LINK_STATE_L1) + link->aspm_enabled |= ASPM_STATE_L1; + link->latency_up.l1 = calc_l1_latency(upreg.latency_encoding_l1); + link->latency_dw.l1 = calc_l1_latency(dwreg.latency_encoding_l1); /* Save default state */ link->aspm_default = link->aspm_enabled; @@ -379,8 +407,7 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) */ list_for_each_entry(child, &linkbus->devices, bus_list) { if (child->pcie_type == PCI_EXP_TYPE_PCI_BRIDGE) { - link->aspm_disable = - PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1; + link->aspm_disable = ASPM_STATE_ALL; break; } } @@ -409,19 +436,20 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) } } -static void pcie_config_aspm_dev(struct pci_dev *pdev, u32 state) +static void pcie_config_aspm_dev(struct pci_dev *pdev, u32 val) { u16 reg16; int pos = pci_find_capability(pdev, PCI_CAP_ID_EXP); pci_read_config_word(pdev, pos + PCI_EXP_LNKCTL, ®16); reg16 &= ~0x3; - reg16 |= state; + reg16 |= val; pci_write_config_word(pdev, pos + PCI_EXP_LNKCTL, reg16); } static void pcie_config_aspm_link(struct pcie_link_state *link, u32 state) { + u32 upstream = 0, dwstream = 0; struct pci_dev *child, *parent = link->pdev; struct pci_bus *linkbus = parent->subordinate; @@ -429,20 +457,27 @@ static void pcie_config_aspm_link(struct pcie_link_state *link, u32 state) state &= (link->aspm_capable & ~link->aspm_disable); if (link->aspm_enabled == state) return; + /* Convert ASPM state to upstream/downstream ASPM register state */ + if (state & ASPM_STATE_L0S_UP) + dwstream |= PCIE_LINK_STATE_L0S; + if (state & ASPM_STATE_L0S_DW) + upstream |= PCIE_LINK_STATE_L0S; + if (state & ASPM_STATE_L1) { + upstream |= PCIE_LINK_STATE_L1; + dwstream |= PCIE_LINK_STATE_L1; + } /* * 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 & PCIE_LINK_STATE_L1) - pcie_config_aspm_dev(parent, state); - + 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, state); - - if (!(state & PCIE_LINK_STATE_L1)) - pcie_config_aspm_dev(parent, state); + pcie_config_aspm_dev(child, dwstream); + if (!(state & ASPM_STATE_L1)) + pcie_config_aspm_dev(parent, upstream); link->aspm_enabled = state; } @@ -673,7 +708,10 @@ void pci_disable_link_state(struct pci_dev *pdev, int state) down_read(&pci_bus_sem); mutex_lock(&aspm_lock); link = parent->link_state; - link->aspm_disable |= 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; pcie_config_aspm_link(link, policy_to_aspm_state(link)); if (state & PCIE_LINK_STATE_CLKPM) { @@ -742,11 +780,17 @@ static ssize_t link_state_store(struct device *dev, { struct pci_dev *pdev = to_pci_dev(dev); struct pcie_link_state *link, *root = pdev->link_state->root; - u32 state = buf[0] - '0'; + u32 val = buf[0] - '0', state = 0; - if (n < 1 || state > 3) + if (n < 1 || val > 3) return -EINVAL; + /* Convert requested state to ASPM state */ + if (val & PCIE_LINK_STATE_L0S) + state |= ASPM_STATE_L0S; + if (val & PCIE_LINK_STATE_L1) + state |= ASPM_STATE_L1; + down_read(&pci_bus_sem); mutex_lock(&aspm_lock); list_for_each_entry(link, &link_list, sibling) { |