From 337001b6c42938f49a880b1b8306c3ed771a7e61 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 7 Jul 2008 03:36:24 +0200 Subject: [PATCH] PCI: Simplify PCI device PM code If the offset of PCI device's PM capability in its configuration space, the mask of states that the device supports PME# from and the D1 and D2 support bits are cached in the corresponding struct pci_dev, the PCI device PM code can be simplified quite a bit. Signed-off-by: Rafael J. Wysocki Signed-off-by: Jesse Barnes --- drivers/pci/pci.c | 118 +++++++++++++++++---------------------- include/linux/pci.h | 8 ++- include/linux/pci_regs.h | 1 + 3 files changed, 60 insertions(+), 67 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 1b0ec45e99..e632a58ba5 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -419,7 +419,6 @@ static inline int platform_pci_sleep_wake(struct pci_dev *dev, bool enable) * pci_raw_set_power_state - Use PCI PM registers to set the power state of * given PCI device * @dev: PCI device to handle. - * @pm: PCI PM capability offset of the device. * @state: PCI power state (D0, D1, D2, D3hot) to put the device into. * * RETURN VALUE: @@ -430,12 +429,12 @@ static inline int platform_pci_sleep_wake(struct pci_dev *dev, bool enable) * 0 if device's power state has been successfully changed. */ static int -pci_raw_set_power_state(struct pci_dev *dev, int pm, pci_power_t state) +pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state) { - u16 pmcsr, pmc; + u16 pmcsr; bool need_restore = false; - if (!pm) + if (!dev->pm_cap) return -EIO; if (state < PCI_D0 || state > PCI_D3hot) @@ -455,20 +454,12 @@ pci_raw_set_power_state(struct pci_dev *dev, int pm, pci_power_t state) return -EINVAL; } - pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc); - - if ((pmc & PCI_PM_CAP_VER_MASK) > 3) { - dev_err(&dev->dev, "unsupported PM cap regs version (%u)\n", - pmc & PCI_PM_CAP_VER_MASK); - return -EIO; - } - /* check if this device supports the desired state */ - if ((state == PCI_D1 && !(pmc & PCI_PM_CAP_D1)) - || (state == PCI_D2 && !(pmc & PCI_PM_CAP_D2))) + if ((state == PCI_D1 && !dev->d1_support) + || (state == PCI_D2 && !dev->d2_support)) return -EIO; - pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr); + pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); /* If we're (effectively) in D3, force entire word to 0. * This doesn't affect PME_Status, disables PME_En, and @@ -492,7 +483,7 @@ pci_raw_set_power_state(struct pci_dev *dev, int pm, pci_power_t state) } /* enter specified state */ - pci_write_config_word(dev, pm + PCI_PM_CTRL, pmcsr); + pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr); /* Mandatory power management transition delays */ /* see PCI PM 1.1 5.6.1 table 18 */ @@ -528,14 +519,13 @@ pci_raw_set_power_state(struct pci_dev *dev, int pm, pci_power_t state) * pci_update_current_state - Read PCI power state of given device from its * PCI PM registers and cache it * @dev: PCI device to handle. - * @pm: PCI PM capability offset of the device. */ -static void pci_update_current_state(struct pci_dev *dev, int pm) +static void pci_update_current_state(struct pci_dev *dev) { - if (pm) { + if (dev->pm_cap) { u16 pmcsr; - pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr); + pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK); } } @@ -557,7 +547,7 @@ static void pci_update_current_state(struct pci_dev *dev, int pm) */ int pci_set_power_state(struct pci_dev *dev, pci_power_t state) { - int pm, error; + int error; /* bound the state we're entering */ if (state > PCI_D3hot) @@ -572,9 +562,6 @@ int pci_set_power_state(struct pci_dev *dev, pci_power_t state) */ return 0; - /* Find PCI PM capability in the list */ - pm = pci_find_capability(dev, PCI_CAP_ID_PM); - if (state == PCI_D0 && platform_pci_power_manageable(dev)) { /* * Allow the platform to change the state, for example via ACPI @@ -582,16 +569,16 @@ int pci_set_power_state(struct pci_dev *dev, pci_power_t state) */ int ret = platform_pci_set_power_state(dev, PCI_D0); if (!ret) - pci_update_current_state(dev, pm); + pci_update_current_state(dev); } - error = pci_raw_set_power_state(dev, pm, state); + error = pci_raw_set_power_state(dev, state); if (state > PCI_D0 && platform_pci_power_manageable(dev)) { /* Allow the platform to finalize the transition */ int ret = platform_pci_set_power_state(dev, state); if (!ret) { - pci_update_current_state(dev, pm); + pci_update_current_state(dev); error = 0; } } @@ -1050,48 +1037,38 @@ int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) /** * pci_pme_capable - check the capability of PCI device to generate PME# * @dev: PCI device to handle. - * @pm: PCI PM capability offset of the device. * @state: PCI state from which device will issue PME#. */ -static bool pci_pme_capable(struct pci_dev *dev, int pm, pci_power_t state) +static bool pci_pme_capable(struct pci_dev *dev, pci_power_t state) { - u16 pmc; - - if (!pm) + if (!dev->pm_cap) return false; - /* Check device's ability to generate PME# from given state */ - pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc); - - pmc &= PCI_PM_CAP_PME_MASK; - pmc >>= ffs(PCI_PM_CAP_PME_MASK) - 1; /* First bit of mask */ - - return !!(pmc & (1 << state)); + return !!(dev->pme_support & (1 << state)); } /** * pci_pme_active - enable or disable PCI device's PME# function * @dev: PCI device to handle. - * @pm: PCI PM capability offset of the device. * @enable: 'true' to enable PME# generation; 'false' to disable it. * * The caller must verify that the device is capable of generating PME# before * calling this function with @enable equal to 'true'. */ -static void pci_pme_active(struct pci_dev *dev, int pm, bool enable) +static void pci_pme_active(struct pci_dev *dev, bool enable) { u16 pmcsr; - if (!pm) + if (!dev->pm_cap) return; - pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr); + pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); /* Clear PME_Status by writing 1 to it and enable PME# */ pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE; if (!enable) pmcsr &= ~PCI_PM_CTRL_PME_ENABLE; - pci_write_config_word(dev, pm + PCI_PM_CTRL, pmcsr); + pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr); dev_printk(KERN_INFO, &dev->dev, "PME# %s\n", enable ? "enabled" : "disabled"); @@ -1118,7 +1095,6 @@ static void pci_pme_active(struct pci_dev *dev, int pm, bool enable) */ int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable) { - int pm; int error = 0; bool pme_done = false; @@ -1134,9 +1110,8 @@ int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable) if (!enable && platform_pci_can_wakeup(dev)) error = platform_pci_sleep_wake(dev, false); - pm = pci_find_capability(dev, PCI_CAP_ID_PM); - if (!enable || pci_pme_capable(dev, pm, state)) { - pci_pme_active(dev, pm, enable); + if (!enable || pci_pme_capable(dev, state)) { + pci_pme_active(dev, enable); pme_done = true; } @@ -1158,7 +1133,6 @@ int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable) int pci_prepare_to_sleep(struct pci_dev *dev) { pci_power_t target_state = PCI_D3hot; - int pm = pci_find_capability(dev, PCI_CAP_ID_PM); int error; if (platform_pci_power_manageable(dev)) { @@ -1186,23 +1160,14 @@ int pci_prepare_to_sleep(struct pci_dev *dev) * wake-up events, make it the target state and enable device * to generate PME#. */ - u16 pmc; - - if (!pm) + if (!dev->pm_cap) return -EIO; - pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc); - if (pmc & PCI_PM_CAP_PME_MASK) { - if (!(pmc & PCI_PM_CAP_PME_D3)) { - /* Device cannot generate PME# from D3_hot */ - if (pmc & PCI_PM_CAP_PME_D2) - target_state = PCI_D2; - else if (pmc & PCI_PM_CAP_PME_D1) - target_state = PCI_D1; - else - target_state = PCI_D0; - } - pci_pme_active(dev, pm, true); + if (dev->pme_support) { + while (target_state + && !(dev->pme_support & (1 << target_state))) + target_state--; + pci_pme_active(dev, true); } } @@ -1236,6 +1201,8 @@ void pci_pm_init(struct pci_dev *dev) int pm; u16 pmc; + dev->pm_cap = 0; + /* find PCI PM capability in list */ pm = pci_find_capability(dev, PCI_CAP_ID_PM); if (!pm) @@ -1249,7 +1216,23 @@ void pci_pm_init(struct pci_dev *dev) return; } - if (pmc & PCI_PM_CAP_PME_MASK) { + dev->pm_cap = pm; + + dev->d1_support = false; + dev->d2_support = false; + if (!pci_no_d1d2(dev)) { + if (pmc & PCI_PM_CAP_D1) { + dev_printk(KERN_DEBUG, &dev->dev, "supports D1\n"); + dev->d1_support = true; + } + if (pmc & PCI_PM_CAP_D2) { + dev_printk(KERN_DEBUG, &dev->dev, "supports D2\n"); + dev->d2_support = true; + } + } + + pmc &= PCI_PM_CAP_PME_MASK; + if (pmc) { dev_printk(KERN_INFO, &dev->dev, "PME# supported from%s%s%s%s%s\n", (pmc & PCI_PM_CAP_PME_D0) ? " D0" : "", @@ -1257,6 +1240,7 @@ void pci_pm_init(struct pci_dev *dev) (pmc & PCI_PM_CAP_PME_D2) ? " D2" : "", (pmc & PCI_PM_CAP_PME_D3) ? " D3hot" : "", (pmc & PCI_PM_CAP_PME_D3cold) ? " D3cold" : ""); + dev->pme_support = pmc >> PCI_PM_CAP_PME_SHIFT; /* * Make device's PM flags reflect the wake-up capability, but * let the user space enable it to wake up the system as needed. @@ -1264,7 +1248,9 @@ void pci_pm_init(struct pci_dev *dev) device_set_wakeup_capable(&dev->dev, true); device_set_wakeup_enable(&dev->dev, false); /* Disable the PME# generation functionality */ - pci_pme_active(dev, pm, false); + pci_pme_active(dev, false); + } else { + dev->pme_support = 0; } } diff --git a/include/linux/pci.h b/include/linux/pci.h index 52ac06dcce..68a29f0f27 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -177,6 +177,13 @@ struct pci_dev { pci_power_t current_state; /* Current operating state. In ACPI-speak, this is D0-D3, D0 being fully functional, and D3 being off. */ + int pm_cap; /* PM capability offset in the + configuration space */ + unsigned int pme_support:5; /* Bitmask of states from which PME# + can be generated */ + unsigned int d1_support:1; /* Low power state D1 is supported */ + unsigned int d2_support:1; /* Low power state D2 is supported */ + unsigned int no_d1d2:1; /* Only allow D0 and D3 */ #ifdef CONFIG_PCIEASPM struct pcie_link_state *link_state; /* ASPM link state. */ @@ -201,7 +208,6 @@ struct pci_dev { unsigned int is_added:1; unsigned int is_busmaster:1; /* device is busmaster */ unsigned int no_msi:1; /* device may not use msi */ - unsigned int no_d1d2:1; /* only allow d0 or d3 */ unsigned int block_ucfg_access:1; /* userspace config space access is blocked */ unsigned int broken_parity_status:1; /* Device generates false positive parity */ unsigned int msi_enabled:1; diff --git a/include/linux/pci_regs.h b/include/linux/pci_regs.h index c0c1223c91..19958b9299 100644 --- a/include/linux/pci_regs.h +++ b/include/linux/pci_regs.h @@ -231,6 +231,7 @@ #define PCI_PM_CAP_PME_D2 0x2000 /* PME# from D2 */ #define PCI_PM_CAP_PME_D3 0x4000 /* PME# from D3 (hot) */ #define PCI_PM_CAP_PME_D3cold 0x8000 /* PME# from D3 (cold) */ +#define PCI_PM_CAP_PME_SHIFT 11 /* Start of the PME Mask in PMC */ #define PCI_PM_CTRL 4 /* PM control and status register */ #define PCI_PM_CTRL_STATE_MASK 0x0003 /* Current power state (D0 to D3) */ #define PCI_PM_CTRL_NO_SOFT_RESET 0x0004 /* No reset for D3hot->D0 */ -- 2.39.5