From 073900a28d95c75a706bf40ebf092ea048c7b236 Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Mon, 12 Apr 2010 13:17:25 +0200 Subject: USB: rename usb_buffer_alloc() and usb_buffer_free() For more clearance what the functions actually do, usb_buffer_alloc() is renamed to usb_alloc_coherent() usb_buffer_free() is renamed to usb_free_coherent() They should only be used in code which really needs DMA coherency. [added compatibility macros so we can convert things easier - gregkh] Signed-off-by: Daniel Mack Cc: Alan Stern Cc: Pedro Ribeiro Signed-off-by: Greg Kroah-Hartman --- include/linux/usb.h | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/usb.h b/include/linux/usb.h index ce1323c4e47c..739f1fd1cc15 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -1085,7 +1085,7 @@ typedef void (*usb_complete_t)(struct urb *); * Alternatively, drivers may pass the URB_NO_xxx_DMA_MAP transfer flags, * which tell the host controller driver that no such mapping is needed since * the device driver is DMA-aware. For example, a device driver might - * allocate a DMA buffer with usb_buffer_alloc() or call usb_buffer_map(). + * allocate a DMA buffer with usb_alloc_coherent() or call usb_buffer_map(). * When these transfer flags are provided, host controller drivers will * attempt to use the dma addresses found in the transfer_dma and/or * setup_dma fields rather than determining a dma address themselves. @@ -1366,11 +1366,23 @@ static inline int usb_urb_dir_out(struct urb *urb) return (urb->transfer_flags & URB_DIR_MASK) == URB_DIR_OUT; } -void *usb_buffer_alloc(struct usb_device *dev, size_t size, +void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags, dma_addr_t *dma); -void usb_buffer_free(struct usb_device *dev, size_t size, +void usb_free_coherent(struct usb_device *dev, size_t size, void *addr, dma_addr_t dma); +/* Compatible macros while we switch over */ +static inline void *usb_buffer_alloc(struct usb_device *dev, size_t size, + gfp_t mem_flags, dma_addr_t *dma) +{ + return usb_alloc_coherent(dev, size, mem_flags, dma); +} +static inline void usb_buffer_free(struct usb_device *dev, size_t size, + void *addr, dma_addr_t dma) +{ + return usb_free_coherent(dev, size, addr, dma); +} + #if 0 struct urb *usb_buffer_map(struct urb *urb); void usb_buffer_dmasync(struct urb *urb); -- cgit v1.2.3-71-gd317 From 6629dcff19470a894ce294d0adb9cbab94ee1fb9 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Tue, 4 May 2010 11:09:28 +0200 Subject: i2c-core: Use per-adapter userspace device lists Using a single list for all userspace devices leads to a dead lock on multiplexed buses in some circumstances (mux chip instantiated from userspace). This is solved by using a separate list for each bus segment. Signed-off-by: Jean Delvare Acked-by: Michael Lawnick --- drivers/i2c/i2c-core.c | 34 ++++++++++++++++++---------------- include/linux/i2c.h | 2 ++ 2 files changed, 20 insertions(+), 16 deletions(-) (limited to 'include/linux') diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 5105126225c3..c2258a51fe0c 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -40,12 +40,11 @@ #include "i2c-core.h" -/* core_lock protects i2c_adapter_idr, userspace_devices, and guarantees +/* core_lock protects i2c_adapter_idr, and guarantees that device detection, deletion of detected devices, and attach_adapter and detach_adapter calls are serialized */ static DEFINE_MUTEX(core_lock); static DEFINE_IDR(i2c_adapter_idr); -static LIST_HEAD(userspace_devices); static struct device_type i2c_client_type; static int i2c_check_addr(struct i2c_adapter *adapter, int addr); @@ -542,9 +541,9 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, return -EEXIST; /* Keep track of the added device */ - mutex_lock(&core_lock); - list_add_tail(&client->detected, &userspace_devices); - mutex_unlock(&core_lock); + i2c_lock_adapter(adap); + list_add_tail(&client->detected, &adap->userspace_clients); + i2c_unlock_adapter(adap); dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", info.type, info.addr); @@ -583,9 +582,10 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, /* Make sure the device was added through sysfs */ res = -ENOENT; - mutex_lock(&core_lock); - list_for_each_entry_safe(client, next, &userspace_devices, detected) { - if (client->addr == addr && client->adapter == adap) { + i2c_lock_adapter(adap); + list_for_each_entry_safe(client, next, &adap->userspace_clients, + detected) { + if (client->addr == addr) { dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", "delete_device", client->name, client->addr); @@ -595,7 +595,7 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, break; } } - mutex_unlock(&core_lock); + i2c_unlock_adapter(adap); if (res < 0) dev_err(dev, "%s: Can't find device in list\n", @@ -677,6 +677,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap) } rt_mutex_init(&adap->bus_lock); + INIT_LIST_HEAD(&adap->userspace_clients); /* Set default timeout to 1 second if not already set */ if (adap->timeout == 0) @@ -879,14 +880,15 @@ int i2c_del_adapter(struct i2c_adapter *adap) return res; /* Remove devices instantiated from sysfs */ - list_for_each_entry_safe(client, next, &userspace_devices, detected) { - if (client->adapter == adap) { - dev_dbg(&adap->dev, "Removing %s at 0x%x\n", - client->name, client->addr); - list_del(&client->detected); - i2c_unregister_device(client); - } + i2c_lock_adapter(adap); + list_for_each_entry_safe(client, next, &adap->userspace_clients, + detected) { + dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, + client->addr); + list_del(&client->detected); + i2c_unregister_device(client); } + i2c_unlock_adapter(adap); /* Detach any active clients. This can't fail, thus we do not checking the returned value. */ diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 0a5da639b327..6ed1d59bfb1e 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -355,6 +355,8 @@ struct i2c_adapter { int nr; char name[48]; struct completion dev_released; + + struct list_head userspace_clients; }; #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) -- cgit v1.2.3-71-gd317 From 1ce7e4ff24fe338438bc7837e02780f202bf202b Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 23 Apr 2010 10:35:52 +0800 Subject: cgroup: Check task_lock in task_subsys_state() Expand task_subsys_state()'s rcu_dereference_check() to include the full locking rule as documented in Documentation/cgroups/cgroups.txt by adding a check for task->alloc_lock being held. This fixes an RCU false positive when resuming from suspend. The warning comes from freezer cgroup in cgroup_freezing_or_frozen(). Signed-off-by: Li Zefan Acked-by: Matt Helsley Signed-off-by: Paul E. McKenney --- include/linux/cgroup.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index b8ad1ea99586..8f78073d7caa 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -530,6 +530,7 @@ static inline struct cgroup_subsys_state *task_subsys_state( { return rcu_dereference_check(task->cgroups->subsys[subsys_id], rcu_read_lock_held() || + lockdep_is_held(&task->alloc_lock) || cgroup_lock_is_held()); } -- cgit v1.2.3-71-gd317 From ee84b8243b07c33a5c8aed42b4b2da60cb16d1d2 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 6 May 2010 09:28:41 -0700 Subject: rcu: create rcu_my_thread_group_empty() wrapper Some RCU-lockdep splat repairs need to know whether they are running in a single-threaded process. Unfortunately, the thread_group_empty() primitive is defined in sched.h, and can induce #include hell. This commit therefore introduces a rcu_my_thread_group_empty() wrapper that is defined in rcupdate.c, thus avoiding the need to include sched.h everywhere. Signed-off-by: "Paul E. McKenney" --- include/linux/rcupdate.h | 2 ++ kernel/rcupdate.c | 11 +++++++++++ 2 files changed, 13 insertions(+) (limited to 'include/linux') diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 07db2feb8572..db266bbed23f 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -190,6 +190,8 @@ static inline int rcu_read_lock_sched_held(void) #ifdef CONFIG_PROVE_RCU +extern int rcu_my_thread_group_empty(void); + /** * rcu_dereference_check - rcu_dereference with debug checking * @p: The pointer to read, prior to dereferencing diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index 03a7ea1579f6..49d808e833b0 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -122,3 +122,14 @@ void wakeme_after_rcu(struct rcu_head *head) rcu = container_of(head, struct rcu_synchronize, head); complete(&rcu->completion); } + +#ifdef CONFIG_PROVE_RCU +/* + * wrapper function to avoid #include problems. + */ +int rcu_my_thread_group_empty(void) +{ + return thread_group_empty(current); +} +EXPORT_SYMBOL_GPL(rcu_my_thread_group_empty); +#endif /* #ifdef CONFIG_PROVE_RCU */ -- cgit v1.2.3-71-gd317