Driver core patches for 4.12-rc1

Very tiny pull request for 4.12-rc1 for the driver core this time
 around.
 
 There are some documentation fixes, an eventpoll.h fixup to make it
 easier for the libc developers to take our header files directly, and
 some very minor driver core fixes and changes.
 
 All have been in linux-next for a very long time with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Very tiny pull request for 4.12-rc1 for the driver core this time
  around.

  There are some documentation fixes, an eventpoll.h fixup to make it
  easier for the libc developers to take our header files directly, and
  some very minor driver core fixes and changes.

  All have been in linux-next for a very long time with no reported
  issues"

* tag 'driver-core-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  Revert "kref: double kref_put() in my_data_handler()"
  driver core: don't initialize 'parent' in device_add()
  drivers: base: dma-mapping: use nth_page helper
  Documentation/ABI: add information about cpu_capacity
  debugfs: set no_llseek in DEFINE_DEBUGFS_ATTRIBUTE
  eventpoll.h: add missing epoll event masks
  eventpoll.h: fix epoll event masks

Documentation/ABI/testing/sysfs-devices-system-cpu

@@ -366,3 +366,10 @@ Contact:	Linux ARM Kernel Mailing list <linux-arm-kernel@lists.infradead.org>
 Description:	AArch64 CPU registers
 		'identification' directory exposes the CPU ID registers for
 		 identifying model and revision of the CPU.
+
+What:		/sys/devices/system/cpu/cpu#/cpu_capacity
+Date:		December 2016
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:	information about CPUs heterogeneity.
+
+		cpu_capacity: capacity of cpu#.

Documentation/kref.txt

@@ -84,6 +84,7 @@ int my_data_handler(void)
 	task = kthread_run(more_data_handling, data, "more_data_handling");
 	if (task == ERR_PTR(-ENOMEM)) {
 		rv = -ENOMEM;
+	        kref_put(&data->refcount, data_release);
 		goto out;
 	}
 

drivers/base/core.c

@@ -1607,7 +1607,7 @@ int device_private_init(struct device *dev)
  */
 int device_add(struct device *dev)
 {
-	struct device *parent = NULL;
+	struct device *parent;
 	struct kobject *kobj;
 	struct class_interface *class_intf;
 	int error = -EINVAL;

drivers/base/dma-mapping.c

@@ -309,14 +309,13 @@ void *dma_common_contiguous_remap(struct page *page, size_t size,
 	int i;
 	struct page **pages;
 	void *ptr;
-	unsigned long pfn;
 
 	pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL);
 	if (!pages)
 		return NULL;
 
-	for (i = 0, pfn = page_to_pfn(page); i < (size >> PAGE_SHIFT); i++)
+	for (i = 0; i < (size >> PAGE_SHIFT); i++)
-		pages[i] = pfn_to_page(pfn + i);
+		pages[i] = nth_page(page, i);
 
 	ptr = dma_common_pages_remap(pages, size, vm_flags, prot, caller);
 

include/linux/debugfs.h

@@ -74,7 +74,7 @@ static const struct file_operations __fops = {				\
 	.release = simple_attr_release,					\
 	.read	 = debugfs_attr_read,					\
 	.write	 = debugfs_attr_write,					\
-	.llseek  = generic_file_llseek,					\
+	.llseek  = no_llseek,						\
 }
 
 #if defined(CONFIG_DEBUG_FS)

include/uapi/linux/eventpoll.h

@@ -26,8 +26,21 @@
 #define EPOLL_CTL_DEL 2
 #define EPOLL_CTL_MOD 3
 
+/* Epoll event masks */
+#define EPOLLIN		0x00000001
+#define EPOLLPRI	0x00000002
+#define EPOLLOUT	0x00000004
+#define EPOLLERR	0x00000008
+#define EPOLLHUP	0x00000010
+#define EPOLLRDNORM	0x00000040
+#define EPOLLRDBAND	0x00000080
+#define EPOLLWRNORM	0x00000100
+#define EPOLLWRBAND	0x00000200
+#define EPOLLMSG	0x00000400
+#define EPOLLRDHUP	0x00002000
+
 /* Set exclusive wakeup mode for the target file descriptor */
-#define EPOLLEXCLUSIVE (1 << 28)
+#define EPOLLEXCLUSIVE (1U << 28)
 
 /*
  * Request the handling of system wakeup events so as to prevent system suspends
@@ -39,13 +52,13 @@
  *
  * Requires CAP_BLOCK_SUSPEND
  */
-#define EPOLLWAKEUP (1 << 29)
+#define EPOLLWAKEUP (1U << 29)
 
 /* Set the One Shot behaviour for the target file descriptor */
-#define EPOLLONESHOT (1 << 30)
+#define EPOLLONESHOT (1U << 30)
 
 /* Set the Edge Triggered behaviour for the target file descriptor */
-#define EPOLLET (1 << 31)
+#define EPOLLET (1U << 31)
 
 /* 
  * On x86-64 make the 64bit structure have the same alignment as the