From a7670d425b75f9e44b7d4d0aea04f4a6d5f34291 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Wed, 19 Jul 2017 17:24:31 -0700 Subject: driver core: make device_{add|remove}_groups() public Many drivers create additional driver-specific device attributes when binding to the device. To avoid them calling SYSFS API directly, let's export these helpers. Signed-off-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index 9ef518af5515..10cf209a4e82 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1200,6 +1200,11 @@ struct device *device_create_with_groups(struct class *cls, const char *fmt, ...); extern void device_destroy(struct class *cls, dev_t devt); +extern int __must_check device_add_groups(struct device *dev, + const struct attribute_group **groups); +extern void device_remove_groups(struct device *dev, + const struct attribute_group **groups); + /* * Platform "fixup" functions - allow the platform to have their say * about devices and actions that the general device layer doesn't -- cgit v1.2.3 From e323b2dddc1ce7ea7f032c986c012a04d5977dc8 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Wed, 19 Jul 2017 17:24:32 -0700 Subject: driver core: add device_{add|remove}_group() helpers We have helpers that work with NULL terminated array of groups, but many drivers only create a single supplemental group, and do not want to declare a group array. Let's provide them with helpers working with a single group. Signed-off-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index 10cf209a4e82..7698a513b35e 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1205,6 +1205,22 @@ extern int __must_check device_add_groups(struct device *dev, extern void device_remove_groups(struct device *dev, const struct attribute_group **groups); +static inline int __must_check device_add_group(struct device *dev, + const struct attribute_group *grp) +{ + const struct attribute_group *groups[] = { grp, NULL }; + + return device_add_groups(dev, groups); +} + +static inline void device_remove_group(struct device *dev, + const struct attribute_group *grp) +{ + const struct attribute_group *groups[] = { grp, NULL }; + + return device_remove_groups(dev, groups); +} + /* * Platform "fixup" functions - allow the platform to have their say * about devices and actions that the general device layer doesn't -- cgit v1.2.3 From 57b8ff070f9897b22e4f80fda775a489fc797008 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Wed, 19 Jul 2017 17:24:33 -0700 Subject: driver core: add devm_device_add_group() and friends Many drivers create additional driver-specific device attributes when binding to the device, and providing managed version of device_create_group() will simplify unbinding and error handling in probe path for such drivers. Without managed version driver writers either have to mix manual and managed resources, which is prone to errors, or open-code this function by providing a wrapper to device_add_group() and use it with devm_add_action() or devm_add_action_or_reset(). Signed-off-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman --- drivers/base/core.c | 130 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/device.h | 9 ++++ 2 files changed, 139 insertions(+) (limited to 'include/linux/device.h') diff --git a/drivers/base/core.c b/drivers/base/core.c index 14f8cf5c8b05..09723532725d 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -1035,6 +1035,136 @@ void device_remove_groups(struct device *dev, } EXPORT_SYMBOL_GPL(device_remove_groups); +union device_attr_group_devres { + const struct attribute_group *group; + const struct attribute_group **groups; +}; + +static int devm_attr_group_match(struct device *dev, void *res, void *data) +{ + return ((union device_attr_group_devres *)res)->group == data; +} + +static void devm_attr_group_remove(struct device *dev, void *res) +{ + union device_attr_group_devres *devres = res; + const struct attribute_group *group = devres->group; + + dev_dbg(dev, "%s: removing group %p\n", __func__, group); + sysfs_remove_group(&dev->kobj, group); +} + +static void devm_attr_groups_remove(struct device *dev, void *res) +{ + union device_attr_group_devres *devres = res; + const struct attribute_group **groups = devres->groups; + + dev_dbg(dev, "%s: removing groups %p\n", __func__, groups); + sysfs_remove_groups(&dev->kobj, groups); +} + +/** + * devm_device_add_group - given a device, create a managed attribute group + * @dev: The device to create the group for + * @grp: The attribute group to create + * + * This function creates a group for the first time. It will explicitly + * warn and error if any of the attribute files being created already exist. + * + * Returns 0 on success or error code on failure. + */ +int devm_device_add_group(struct device *dev, const struct attribute_group *grp) +{ + union device_attr_group_devres *devres; + int error; + + devres = devres_alloc(devm_attr_group_remove, + sizeof(*devres), GFP_KERNEL); + if (!devres) + return -ENOMEM; + + error = sysfs_create_group(&dev->kobj, grp); + if (error) { + devres_free(devres); + return error; + } + + devres->group = grp; + devres_add(dev, devres); + return 0; +} +EXPORT_SYMBOL_GPL(devm_device_add_group); + +/** + * devm_device_remove_group: remove a managed group from a device + * @dev: device to remove the group from + * @grp: group to remove + * + * This function removes a group of attributes from a device. The attributes + * previously have to have been created for this group, otherwise it will fail. + */ +void devm_device_remove_group(struct device *dev, + const struct attribute_group *grp) +{ + WARN_ON(devres_release(dev, devm_attr_group_remove, + devm_attr_group_match, + /* cast away const */ (void *)grp)); +} +EXPORT_SYMBOL_GPL(devm_device_remove_group); + +/** + * devm_device_add_groups - create a bunch of managed attribute groups + * @dev: The device to create the group for + * @groups: The attribute groups to create, NULL terminated + * + * This function creates a bunch of managed attribute groups. If an error + * occurs when creating a group, all previously created groups will be + * removed, unwinding everything back to the original state when this + * function was called. It will explicitly warn and error if any of the + * attribute files being created already exist. + * + * Returns 0 on success or error code from sysfs_create_group on failure. + */ +int devm_device_add_groups(struct device *dev, + const struct attribute_group **groups) +{ + union device_attr_group_devres *devres; + int error; + + devres = devres_alloc(devm_attr_groups_remove, + sizeof(*devres), GFP_KERNEL); + if (!devres) + return -ENOMEM; + + error = sysfs_create_groups(&dev->kobj, groups); + if (error) { + devres_free(devres); + return error; + } + + devres->groups = groups; + devres_add(dev, devres); + return 0; +} +EXPORT_SYMBOL_GPL(devm_device_add_groups); + +/** + * devm_device_remove_groups - remove a list of managed groups + * + * @dev: The device for the groups to be removed from + * @groups: NULL terminated list of groups to be removed + * + * If groups is not NULL, remove the specified groups from the device. + */ +void devm_device_remove_groups(struct device *dev, + const struct attribute_group **groups) +{ + WARN_ON(devres_release(dev, devm_attr_groups_remove, + devm_attr_group_match, + /* cast away const */ (void *)groups)); +} +EXPORT_SYMBOL_GPL(devm_device_remove_groups); + static int device_add_attrs(struct device *dev) { struct class *class = dev->class; diff --git a/include/linux/device.h b/include/linux/device.h index 7698a513b35e..f52288c24734 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1221,6 +1221,15 @@ static inline void device_remove_group(struct device *dev, return device_remove_groups(dev, groups); } +extern int __must_check devm_device_add_groups(struct device *dev, + const struct attribute_group **groups); +extern void devm_device_remove_groups(struct device *dev, + const struct attribute_group **groups); +extern int __must_check devm_device_add_group(struct device *dev, + const struct attribute_group *grp); +extern void devm_device_remove_group(struct device *dev, + const struct attribute_group *grp); + /* * Platform "fixup" functions - allow the platform to have their say * about devices and actions that the general device layer doesn't -- cgit v1.2.3 From 0cca6c8920ade95e2741b2062cf1397dc546fb0f Mon Sep 17 00:00:00 2001 From: Ludovic Desroches Date: Sun, 6 Aug 2017 16:00:05 +0200 Subject: pinctrl: generic: update references to Documentation/pinctrl.txt Update deprecated references to Documentation/pinctrl.txt since it has been moved to Documentation/driver-api/pinctl.rst. Signed-off-by: Ludovic Desroches Fixes: 5a9b73832e9e ("pinctrl.txt: move it to the driver-api book") Signed-off-by: Linus Walleij --- Documentation/gpio/gpio-legacy.txt | 2 +- MAINTAINERS | 2 +- include/linux/device.h | 2 +- include/linux/pinctrl/pinconf-generic.h | 4 ++-- 4 files changed, 5 insertions(+), 5 deletions(-) (limited to 'include/linux/device.h') diff --git a/Documentation/gpio/gpio-legacy.txt b/Documentation/gpio/gpio-legacy.txt index b34fd94f7089..5eacc147ea87 100644 --- a/Documentation/gpio/gpio-legacy.txt +++ b/Documentation/gpio/gpio-legacy.txt @@ -459,7 +459,7 @@ pin controller? This is done by registering "ranges" of pins, which are essentially cross-reference tables. These are described in -Documentation/pinctrl.txt +Documentation/driver-api/pinctl.rst While the pin allocation is totally managed by the pinctrl subsystem, gpio (under gpiolib) is still maintained by gpio drivers. It may happen diff --git a/MAINTAINERS b/MAINTAINERS index f66488dfdbc9..2c85558aec19 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10375,7 +10375,7 @@ L: linux-gpio@vger.kernel.org T: git git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl.git S: Maintained F: Documentation/devicetree/bindings/pinctrl/ -F: Documentation/pinctrl.txt +F: Documentation/driver-api/pinctl.rst F: drivers/pinctrl/ F: include/linux/pinctrl/ diff --git a/include/linux/device.h b/include/linux/device.h index 723cd54b94da..beabdbc08420 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -843,7 +843,7 @@ struct dev_links_info { * hibernation, system resume and during runtime PM transitions * along with subsystem-level and driver-level callbacks. * @pins: For device pin management. - * See Documentation/pinctrl.txt for details. + * See Documentation/driver-api/pinctl.rst for details. * @msi_list: Hosts MSI descriptors * @msi_domain: The generic MSI domain this device is using. * @numa_node: NUMA node this device is close to. diff --git a/include/linux/pinctrl/pinconf-generic.h b/include/linux/pinctrl/pinconf-generic.h index 231d3075815a..e91d1b6a260d 100644 --- a/include/linux/pinctrl/pinconf-generic.h +++ b/include/linux/pinctrl/pinconf-generic.h @@ -81,8 +81,8 @@ * it. * @PIN_CONFIG_OUTPUT: this will configure the pin as an output and drive a * value on the line. Use argument 1 to indicate high level, argument 0 to - * indicate low level. (Please see Documentation/pinctrl.txt, section - * "GPIO mode pitfalls" for a discussion around this parameter.) + * indicate low level. (Please see Documentation/driver-api/pinctl.rst, + * section "GPIO mode pitfalls" for a discussion around this parameter.) * @PIN_CONFIG_POWER_SOURCE: if the pin can select between different power * supplies, the argument to this parameter (on a custom format) tells * the driver which alternative power source to use. -- cgit v1.2.3 From 6a7a81761bee2a6694c0a5fb1a16b263c96241c1 Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Thu, 24 Aug 2017 16:09:10 -0600 Subject: driver core: Document struct device:dma_ops Commit 5657933dbb6e (treewide: Move dma_ops from struct dev_archdata into struct device) added the dma_ops field to struct device, but did not update the kerneldoc comment, yielding this warning: ./include/linux/device.h:969: warning: No description found for parameter 'dma_ops' Add a description and bring a little peace to the world. Signed-off-by: Jonathan Corbet Reviewed-by: Bart Van Assche Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index 5db26b9c0fcc..d5bcc5f109eb 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -847,6 +847,7 @@ struct dev_links_info { * @msi_list: Hosts MSI descriptors * @msi_domain: The generic MSI domain this device is using. * @numa_node: NUMA node this device is close to. + * @dma_ops: DMA mapping operations for this device. * @dma_mask: Dma mask (if dma'ble device). * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all * hardware supports 64-bit addresses for consistent allocations -- cgit v1.2.3 From 7521621e600aeefe5ffcc1f90ae26a42fc20c452 Mon Sep 17 00:00:00 2001 From: Michal Suchanek Date: Fri, 11 Aug 2017 15:44:43 +0200 Subject: Do not disable driver and bus shutdown hook when class shutdown hook is set. As seen from the implementation of the single class shutdown hook this is not very sound design. Rename the class shutdown hook to shutdown_pre to make it clear it runs before the driver shutdown hook. Signed-off-by: Michal Suchanek Reviewed-by: Jarkko Sakkinen Signed-off-by: Greg Kroah-Hartman --- drivers/base/core.c | 9 +++++---- drivers/char/tpm/tpm-chip.c | 11 ++--------- include/linux/device.h | 4 ++-- 3 files changed, 9 insertions(+), 15 deletions(-) (limited to 'include/linux/device.h') diff --git a/drivers/base/core.c b/drivers/base/core.c index cb4b5b1f1b09..12ebd055724c 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -2796,11 +2796,12 @@ void device_shutdown(void) pm_runtime_get_noresume(dev); pm_runtime_barrier(dev); - if (dev->class && dev->class->shutdown) { + if (dev->class && dev->class->shutdown_pre) { if (initcall_debug) - dev_info(dev, "shutdown\n"); - dev->class->shutdown(dev); - } else if (dev->bus && dev->bus->shutdown) { + dev_info(dev, "shutdown_pre\n"); + dev->class->shutdown_pre(dev); + } + if (dev->bus && dev->bus->shutdown) { if (initcall_debug) dev_info(dev, "shutdown\n"); dev->bus->shutdown(dev); diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 67ec9d3d04f5..0eca20c5a80c 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -164,14 +164,7 @@ static int tpm_class_shutdown(struct device *dev) chip->ops = NULL; up_write(&chip->ops_sem); } - /* Allow bus- and device-specific code to run. Note: since chip->ops - * is NULL, more-specific shutdown code will not be able to issue TPM - * commands. - */ - if (dev->bus && dev->bus->shutdown) - dev->bus->shutdown(dev); - else if (dev->driver && dev->driver->shutdown) - dev->driver->shutdown(dev); + return 0; } @@ -214,7 +207,7 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev, device_initialize(&chip->devs); chip->dev.class = tpm_class; - chip->dev.class->shutdown = tpm_class_shutdown; + chip->dev.class->shutdown_pre = tpm_class_shutdown; chip->dev.release = tpm_dev_release; chip->dev.parent = pdev; chip->dev.groups = chip->groups; diff --git a/include/linux/device.h b/include/linux/device.h index d5bcc5f109eb..c6f27207dbe8 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -375,7 +375,7 @@ int subsys_virtual_register(struct bus_type *subsys, * @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: Called at shut-down time to quiesce the device. + * @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. * @pm: The default device power management operations of this class. @@ -404,7 +404,7 @@ struct class { int (*suspend)(struct device *dev, pm_message_t state); int (*resume)(struct device *dev); - int (*shutdown)(struct device *dev); + int (*shutdown_pre)(struct device *dev); const struct kobj_ns_type_operations *ns_type; const void *(*namespace)(struct device *dev); -- cgit v1.2.3 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 v1.2.3 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 v1.2.3 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 v1.2.3 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 v1.2.3 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 v1.2.3