From 74378c5c8cdaf0ce9f65e67cbd0613286f2c3bad Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 5 Sep 2017 20:16:27 +0200 Subject: driver core: Fix link to device power management documentation Correct location as of commit 2728b2d2e5be4b82 (PM / core / docs: Convert sleep states API document to reST). Fixes: 2728b2d2e5be4b82 (PM / core / docs: Convert sleep states API document to reST) Signed-off-by: Geert Uytterhoeven Signed-off-by: Rafael J. Wysocki --- include/linux/device.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index c6f27207dbe8..1d2607923a24 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -838,7 +838,7 @@ struct dev_links_info { * @driver_data: Private pointer for driver specific info. * @links: Links to suppliers and consumers of this device. * @power: For device power management. - * See Documentation/power/admin-guide/devices.rst for details. + * See Documentation/driver-api/pm/devices.rst for details. * @pm_domain: Provide callbacks that are executed during system suspend, * hibernation, system resume and during runtime PM transitions * along with subsystem-level and driver-level callbacks. -- cgit From 850fdec8d2fd1eebfa003fea39bec08cd69b6155 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 18 Sep 2017 12:17:57 +0200 Subject: driver core: remove DRIVER_ATTR DRIVER_ATTR is no longer in use, and driver authors should be using DRIVER_ATTR_RW() or DRIVER_ATTR_RO() or DRIVER_ATTR_WO() instead in order to always get the permissions correct. So remove it so that no one can use it anymore. Acked-by: Alan Tull Reviewed-by: Moritz Fischer Signed-off-by: Greg Kroah-Hartman --- Documentation/driver-model/driver.txt | 7 ++++--- Documentation/filesystems/sysfs.txt | 3 ++- include/linux/device.h | 2 -- 3 files changed, 6 insertions(+), 6 deletions(-) (limited to 'include/linux/device.h') diff --git a/Documentation/driver-model/driver.txt b/Documentation/driver-model/driver.txt index 4421135826a2..d661e6f7e6a0 100644 --- a/Documentation/driver-model/driver.txt +++ b/Documentation/driver-model/driver.txt @@ -196,12 +196,13 @@ struct driver_attribute { }; Device drivers can export attributes via their sysfs directories. -Drivers can declare attributes using a DRIVER_ATTR macro that works -identically to the DEVICE_ATTR macro. +Drivers can declare attributes using a DRIVER_ATTR_RW and DRIVER_ATTR_RO +macro that works identically to the DEVICE_ATTR_RW and DEVICE_ATTR_RO +macros. Example: -DRIVER_ATTR(debug,0644,show_debug,store_debug); +DRIVER_ATTR_RW(debug); This is equivalent to declaring: diff --git a/Documentation/filesystems/sysfs.txt b/Documentation/filesystems/sysfs.txt index 24da7b32c489..9a3658cc399e 100644 --- a/Documentation/filesystems/sysfs.txt +++ b/Documentation/filesystems/sysfs.txt @@ -366,7 +366,8 @@ struct driver_attribute { Declaring: -DRIVER_ATTR(_name, _mode, _show, _store) +DRIVER_ATTR_RO(_name) +DRIVER_ATTR_RW(_name) Creation/Removal: diff --git a/include/linux/device.h b/include/linux/device.h index c6f27207dbe8..2bc70ddda09b 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -307,8 +307,6 @@ struct driver_attribute { size_t count); }; -#define DRIVER_ATTR(_name, _mode, _show, _store) \ - struct driver_attribute driver_attr_##_name = __ATTR(_name, _mode, _show, _store) #define DRIVER_ATTR_RW(_name) \ struct driver_attribute driver_attr_##_name = __ATTR_RW(_name) #define DRIVER_ATTR_RO(_name) \ -- cgit From a380f2edef65b2447a043251bb3c00a9d2153a8b Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 25 Sep 2017 14:56:44 +0200 Subject: PM / core: Drop legacy class suspend/resume operations There are no classes using the legacy suspend/resume operations in the tree any more, so drop these operations and update the code referring to them accordingly. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman --- drivers/base/power/main.c | 32 +++++++++----------------------- include/linux/device.h | 5 ----- 2 files changed, 9 insertions(+), 28 deletions(-) (limited to 'include/linux/device.h') diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 770b1539a083..12abcf6084a5 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -848,16 +848,10 @@ static int device_resume(struct device *dev, pm_message_t state, bool async) goto Driver; } - if (dev->class) { - if (dev->class->pm) { - info = "class "; - callback = pm_op(dev->class->pm, state); - goto Driver; - } else if (dev->class->resume) { - info = "legacy class "; - callback = dev->class->resume; - goto End; - } + if (dev->class && dev->class->pm) { + info = "class "; + callback = pm_op(dev->class->pm, state); + goto Driver; } if (dev->bus) { @@ -1508,17 +1502,10 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async) goto Run; } - if (dev->class) { - if (dev->class->pm) { - info = "class "; - callback = pm_op(dev->class->pm, state); - goto Run; - } else if (dev->class->suspend) { - pm_dev_dbg(dev, state, "legacy class "); - error = legacy_suspend(dev, state, dev->class->suspend, - "legacy class "); - goto End; - } + if (dev->class && dev->class->pm) { + info = "class "; + callback = pm_op(dev->class->pm, state); + goto Run; } if (dev->bus) { @@ -1862,8 +1849,7 @@ void device_pm_check_callbacks(struct device *dev) dev->power.no_pm_callbacks = (!dev->bus || (pm_ops_is_empty(dev->bus->pm) && !dev->bus->suspend && !dev->bus->resume)) && - (!dev->class || (pm_ops_is_empty(dev->class->pm) && - !dev->class->suspend && !dev->class->resume)) && + (!dev->class || pm_ops_is_empty(dev->class->pm)) && (!dev->type || pm_ops_is_empty(dev->type->pm)) && (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) && (!dev->driver || (pm_ops_is_empty(dev->driver->pm) && diff --git a/include/linux/device.h b/include/linux/device.h index 1d2607923a24..c1527f887050 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -372,9 +372,6 @@ int subsys_virtual_register(struct bus_type *subsys, * @devnode: Callback to provide the devtmpfs. * @class_release: Called to release this class. * @dev_release: Called to release the device. - * @suspend: Used to put the device to sleep mode, usually to a low power - * state. - * @resume: Used to bring the device from the sleep mode. * @shutdown_pre: Called at shut-down time before driver shutdown. * @ns_type: Callbacks so sysfs can detemine namespaces. * @namespace: Namespace of the device belongs to this class. @@ -402,8 +399,6 @@ struct class { void (*class_release)(struct class *class); void (*dev_release)(struct device *dev); - int (*suspend)(struct device *dev, pm_message_t state); - int (*resume)(struct device *dev); int (*shutdown_pre)(struct device *dev); const struct kobj_ns_type_operations *ns_type; -- cgit From d89e2378a97fafdc74cbf997e7c88af75b81610a Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Thu, 12 Oct 2017 16:56:14 +0100 Subject: drivers: flag buses which demand DMA configuration We do not want the common dma_configure() pathway to apply indiscriminately to all devices, since there are plenty of buses which do not have DMA capability, and if their child devices were used for DMA API calls it would only be indicative of a driver bug. However, there are a number of buses for which DMA is implicitly expected even when not described by firmware - those we whitelist with an automatic opt-in to dma_configure(), assuming that the DMA address space and the physical address space are equivalent if not otherwise specified. Commit 723288836628 ("of: restrict DMA configuration") introduced a short-term fix by comparing explicit bus types, but this approach is far from pretty, doesn't scale well, and fails to cope at all with bus drivers which may be built as modules, like host1x. Let's refine things by making that opt-in a property of the bus type, which neatly addresses those problems and lets the decision of whether firmware description of DMA capability should be optional or mandatory stay internal to the bus drivers themselves. Signed-off-by: Robin Murphy Acked-by: Rob Herring Acked-by: Greg Kroah-Hartman Acked-by: Thierry Reding Signed-off-by: Christoph Hellwig --- drivers/amba/bus.c | 1 + drivers/base/platform.c | 1 + drivers/gpu/host1x/bus.c | 1 + drivers/of/device.c | 8 +------- drivers/pci/pci-driver.c | 1 + include/linux/device.h | 4 ++++ 6 files changed, 9 insertions(+), 7 deletions(-) (limited to 'include/linux/device.h') diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index e0f74ddc22b7..594c228d2f02 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -195,6 +195,7 @@ struct bus_type amba_bustype = { .match = amba_match, .uevent = amba_uevent, .pm = &amba_pm, + .force_dma = true, }; static int __init amba_init(void) diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 9045c5f3734e..c203fb90c1a0 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -1143,6 +1143,7 @@ struct bus_type platform_bus_type = { .match = platform_match, .uevent = platform_uevent, .pm = &platform_dev_pm_ops, + .force_dma = true, }; EXPORT_SYMBOL_GPL(platform_bus_type); diff --git a/drivers/gpu/host1x/bus.c b/drivers/gpu/host1x/bus.c index f9cde03030fd..ed03b3243195 100644 --- a/drivers/gpu/host1x/bus.c +++ b/drivers/gpu/host1x/bus.c @@ -320,6 +320,7 @@ struct bus_type host1x_bus_type = { .name = "host1x", .match = host1x_device_match, .pm = &host1x_device_pm_ops, + .force_dma = true, }; static void __host1x_device_del(struct host1x_device *device) diff --git a/drivers/of/device.c b/drivers/of/device.c index 64b710265d39..25bddf9c9fe1 100644 --- a/drivers/of/device.c +++ b/drivers/of/device.c @@ -9,9 +9,7 @@ #include #include #include -#include #include -#include #include #include "of_private.h" @@ -101,11 +99,7 @@ int of_dma_configure(struct device *dev, struct device_node *np) * DMA configuration regardless of whether "dma-ranges" is * correctly specified or not. */ - if (!dev_is_pci(dev) && -#ifdef CONFIG_ARM_AMBA - dev->bus != &amba_bustype && -#endif - dev->bus != &platform_bus_type) + if (!dev->bus->force_dma) return ret == -ENODEV ? 0 : ret; dma_addr = offset = 0; diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 11bd267fc137..38bdb97b6dc6 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -1466,6 +1466,7 @@ struct bus_type pci_bus_type = { .drv_groups = pci_drv_groups, .pm = PCI_PM_OPS_PTR, .num_vf = pci_bus_num_vf, + .force_dma = true, }; EXPORT_SYMBOL(pci_bus_type); diff --git a/include/linux/device.h b/include/linux/device.h index 66fe271c2544..d60f7701e245 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -97,6 +97,8 @@ extern void bus_remove_file(struct bus_type *, struct bus_attribute *); * @p: The private data of the driver core, only the driver core can * touch this. * @lock_key: Lock class key for use by the lock validator + * @force_dma: Assume devices on this bus should be set up by dma_configure() + * even if DMA capability is not explicitly described by firmware. * * A bus is a channel between the processor and one or more devices. For the * purposes of the device model, all devices are connected via a bus, even if @@ -135,6 +137,8 @@ struct bus_type { struct subsys_private *p; struct lock_class_key lock_key; + + bool force_dma; }; extern int __must_check bus_register(struct bus_type *bus); -- cgit From 08810a4119aaebf6318f209ec5dd9828e969cba4 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 25 Oct 2017 14:12:29 +0200 Subject: PM / core: Add NEVER_SKIP and SMART_PREPARE driver flags The motivation for this change is to provide a way to work around a problem with the direct-complete mechanism used for avoiding system suspend/resume handling for devices in runtime suspend. The problem is that some middle layer code (the PCI bus type and the ACPI PM domain in particular) returns positive values from its system suspend ->prepare callbacks regardless of whether the driver's ->prepare returns a positive value or 0, which effectively prevents drivers from being able to control the direct-complete feature. Some drivers need that control, however, and the PCI bus type has grown its own flag to deal with this issue, but since it is not limited to PCI, it is better to address it by adding driver flags at the core level. To that end, add a driver_flags field to struct dev_pm_info for flags that can be set by device drivers at the probe time to inform the PM core and/or bus types, PM domains and so on on the capabilities and/or preferences of device drivers. Also add two static inline helpers for setting that field and testing it against a given set of flags and make the driver core clear it automatically on driver remove and probe failures. Define and document two PM driver flags related to the direct- complete feature: NEVER_SKIP and SMART_PREPARE that can be used, respectively, to indicate to the PM core that the direct-complete mechanism should never be used for the device and to inform the middle layer code (bus types, PM domains etc) that it can only request the PM core to use the direct-complete mechanism for the device (by returning a positive value from its ->prepare callback) if it also has been requested by the driver. While at it, make the core check pm_runtime_suspended() when setting power.direct_complete so that it doesn't need to be checked by ->prepare callbacks. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Acked-by: Bjorn Helgaas Reviewed-by: Ulf Hansson --- Documentation/driver-api/pm/devices.rst | 14 ++++++++++++++ Documentation/power/pci.txt | 19 +++++++++++++++++++ drivers/acpi/device_pm.c | 13 +++++++++---- drivers/base/dd.c | 2 ++ drivers/base/power/main.c | 4 +++- drivers/pci/pci-driver.c | 5 ++++- include/linux/device.h | 10 ++++++++++ include/linux/pm.h | 20 ++++++++++++++++++++ 8 files changed, 81 insertions(+), 6 deletions(-) (limited to 'include/linux/device.h') diff --git a/Documentation/driver-api/pm/devices.rst b/Documentation/driver-api/pm/devices.rst index 4a18ef9997c0..8add5b302a89 100644 --- a/Documentation/driver-api/pm/devices.rst +++ b/Documentation/driver-api/pm/devices.rst @@ -354,6 +354,20 @@ the phases are: ``prepare``, ``suspend``, ``suspend_late``, ``suspend_noirq``. is because all such devices are initially set to runtime-suspended with runtime PM disabled. + This feature also can be controlled by device drivers by using the + ``DPM_FLAG_NEVER_SKIP`` and ``DPM_FLAG_SMART_PREPARE`` driver power + management flags. [Typically, they are set at the time the driver is + probed against the device in question by passing them to the + :c:func:`dev_pm_set_driver_flags` helper function.] If the first of + these flags is set, the PM core will not apply the direct-complete + procedure described above to the given device and, consequenty, to any + of its ancestors. The second flag, when set, informs the middle layer + code (bus types, device types, PM domains, classes) that it should take + the return value of the ``->prepare`` callback provided by the driver + into account and it may only return a positive value from its own + ``->prepare`` callback if the driver's one also has returned a positive + value. + 2. The ``->suspend`` methods should quiesce the device to stop it from performing I/O. They also may save the device registers and put it into the appropriate low-power state, depending on the bus type the device is diff --git a/Documentation/power/pci.txt b/Documentation/power/pci.txt index a1b7f7158930..ab4e7d0540c1 100644 --- a/Documentation/power/pci.txt +++ b/Documentation/power/pci.txt @@ -961,6 +961,25 @@ dev_pm_ops to indicate that one suspend routine is to be pointed to by the .suspend(), .freeze(), and .poweroff() members and one resume routine is to be pointed to by the .resume(), .thaw(), and .restore() members. +3.1.19. Driver Flags for Power Management + +The PM core allows device drivers to set flags that influence the handling of +power management for the devices by the core itself and by middle layer code +including the PCI bus type. The flags should be set once at the driver probe +time with the help of the dev_pm_set_driver_flags() function and they should not +be updated directly afterwards. + +The DPM_FLAG_NEVER_SKIP flag prevents the PM core from using the direct-complete +mechanism allowing device suspend/resume callbacks to be skipped if the device +is in runtime suspend when the system suspend starts. That also affects all of +the ancestors of the device, so this flag should only be used if absolutely +necessary. + +The DPM_FLAG_SMART_PREPARE flag instructs the PCI bus type to only return a +positive value from pci_pm_prepare() if the ->prepare callback provided by the +driver of the device returns a positive value. That allows the driver to opt +out from using the direct-complete mechanism dynamically. + 3.2. Device Runtime Power Management ------------------------------------ In addition to providing device power management callbacks PCI device drivers diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index 17e8eb93a76c..b4dcc6144e6b 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -959,11 +959,16 @@ static bool acpi_dev_needs_resume(struct device *dev, struct acpi_device *adev) int acpi_subsys_prepare(struct device *dev) { struct acpi_device *adev = ACPI_COMPANION(dev); - int ret; - ret = pm_generic_prepare(dev); - if (ret < 0) - return ret; + if (dev->driver && dev->driver->pm && dev->driver->pm->prepare) { + int ret = dev->driver->pm->prepare(dev); + + if (ret < 0) + return ret; + + if (!ret && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE)) + return 0; + } if (!adev || !pm_runtime_suspended(dev)) return 0; diff --git a/drivers/base/dd.c b/drivers/base/dd.c index ad44b40fe284..45575e134696 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -464,6 +464,7 @@ pinctrl_bind_failed: if (dev->pm_domain && dev->pm_domain->dismiss) dev->pm_domain->dismiss(dev); pm_runtime_reinit(dev); + dev_pm_set_driver_flags(dev, 0); switch (ret) { case -EPROBE_DEFER: @@ -869,6 +870,7 @@ static void __device_release_driver(struct device *dev, struct device *parent) if (dev->pm_domain && dev->pm_domain->dismiss) dev->pm_domain->dismiss(dev); pm_runtime_reinit(dev); + dev_pm_set_driver_flags(dev, 0); klist_remove(&dev->p->knode_driver); device_pm_check_callbacks(dev); diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 9bbbbb13a9db..c0135cd95ada 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -1700,7 +1700,9 @@ unlock: * applies to suspend transitions, however. */ spin_lock_irq(&dev->power.lock); - dev->power.direct_complete = ret > 0 && state.event == PM_EVENT_SUSPEND; + dev->power.direct_complete = state.event == PM_EVENT_SUSPEND && + pm_runtime_suspended(dev) && ret > 0 && + !dev_pm_test_driver_flags(dev, DPM_FLAG_NEVER_SKIP); spin_unlock_irq(&dev->power.lock); return 0; } diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 11bd267fc137..68a32703b30a 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -689,8 +689,11 @@ static int pci_pm_prepare(struct device *dev) if (drv && drv->pm && drv->pm->prepare) { int error = drv->pm->prepare(dev); - if (error) + if (error < 0) return error; + + if (!error && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE)) + return 0; } return pci_dev_keep_suspended(to_pci_dev(dev)); } diff --git a/include/linux/device.h b/include/linux/device.h index c32e6f974d4a..fb9451599aca 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1070,6 +1070,16 @@ static inline void dev_pm_syscore_device(struct device *dev, bool val) #endif } +static inline void dev_pm_set_driver_flags(struct device *dev, u32 flags) +{ + dev->power.driver_flags = flags; +} + +static inline bool dev_pm_test_driver_flags(struct device *dev, u32 flags) +{ + return !!(dev->power.driver_flags & flags); +} + static inline void device_lock(struct device *dev) { mutex_lock(&dev->mutex); diff --git a/include/linux/pm.h b/include/linux/pm.h index a0ceeccf2846..f10bad831bfa 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -550,6 +550,25 @@ struct pm_subsys_data { #endif }; +/* + * Driver flags to control system suspend/resume behavior. + * + * These flags can be set by device drivers at the probe time. They need not be + * cleared by the drivers as the driver core will take care of that. + * + * NEVER_SKIP: Do not skip system suspend/resume callbacks for the device. + * SMART_PREPARE: Check the return value of the driver's ->prepare callback. + * + * Setting SMART_PREPARE instructs bus types and PM domains which may want + * system suspend/resume callbacks to be skipped for the device to return 0 from + * their ->prepare callbacks if the driver's ->prepare callback returns 0 (in + * other words, the system suspend/resume callbacks can only be skipped for the + * device if its driver doesn't object against that). This flag has no effect + * if NEVER_SKIP is set. + */ +#define DPM_FLAG_NEVER_SKIP BIT(0) +#define DPM_FLAG_SMART_PREPARE BIT(1) + struct dev_pm_info { pm_message_t power_state; unsigned int can_wakeup:1; @@ -561,6 +580,7 @@ struct dev_pm_info { bool is_late_suspended:1; bool early_init:1; /* Owned by the PM core */ bool direct_complete:1; /* Owned by the PM core */ + u32 driver_flags; spinlock_t lock; #ifdef CONFIG_PM_SLEEP struct list_head entry; -- cgit