Merge tag 'driver-core-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here's the "big" driver core update for 4.7-rc1.

  Mostly just debugfs changes, the long-known and messy races with
  removing debugfs files should be fixed thanks to the great work of
  Nicolai Stange.  We also have some isa updates in here (the x86
  maintainers told me to take it through this tree), a new warning when
  we run out of dynamic char major numbers, and a few other assorted
  changes, details in the shortlog.

  All have been in linux-next for some time with no reported issues"

* tag 'driver-core-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (32 commits)
  Revert "base: dd: don't remove driver_data in -EPROBE_DEFER case"
  gpio: ws16c48: Utilize the ISA bus driver
  gpio: 104-idio-16: Utilize the ISA bus driver
  gpio: 104-idi-48: Utilize the ISA bus driver
  gpio: 104-dio-48e: Utilize the ISA bus driver
  watchdog: ebc-c384_wdt: Utilize the ISA bus driver
  iio: stx104: Utilize the module_isa_driver and max_num_isa_dev macros
  iio: stx104: Add X86 dependency to STX104 Kconfig option
  Documentation: Add ISA bus driver documentation
  isa: Implement the max_num_isa_dev macro
  isa: Implement the module_isa_driver macro
  pnp: pnpbios: Add explicit X86_32 dependency to PNPBIOS
  isa: Decouple X86_32 dependency from the ISA Kconfig option
  driver-core: use 'dev' argument in dev_dbg_ratelimited stub
  base: dd: don't remove driver_data in -EPROBE_DEFER case
  kernfs: Move faulting copy_user operations outside of the mutex
  devcoredump: add scatterlist support
  debugfs: unproxify files created through debugfs_create_u32_array()
  debugfs: unproxify files created through debugfs_create_blob()
  debugfs: unproxify files created through debugfs_create_bool()
  ...

6 files changed, 164 insertions, 13 deletions

diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
index 981e53ab84e8..1438e2322d5c 100644
--- a/include/linux/debugfs.h
+++ b/include/linux/debugfs.h
@@ -19,9 +19,11 @@
 #include <linux/seq_file.h>
 
 #include <linux/types.h>
+#include <linux/compiler.h>
 
 struct device;
 struct file_operations;
+struct srcu_struct;
 
 struct debugfs_blob_wrapper {
         void *data;
@@ -41,14 +43,16 @@ struct debugfs_regset32 {
 
 extern struct dentry *arch_debugfs_dir;
 
-#if defined(CONFIG_DEBUG_FS)
+extern struct srcu_struct debugfs_srcu;
 
-/* declared over in file.c */
-extern const struct file_operations debugfs_file_operations;
+#if defined(CONFIG_DEBUG_FS)
 
 struct dentry *debugfs_create_file(const char *name, umode_t mode,
                                    struct dentry *parent, void *data,
                                    const struct file_operations *fops);
+struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode,
+                                   struct dentry *parent, void *data,
+                                   const struct file_operations *fops);
 
 struct dentry *debugfs_create_file_size(const char *name, umode_t mode,
                                         struct dentry *parent, void *data,
@@ -68,6 +72,31 @@ struct dentry *debugfs_create_automount(const char *name,
 void debugfs_remove(struct dentry *dentry);
 void debugfs_remove_recursive(struct dentry *dentry);
 
+int debugfs_use_file_start(const struct dentry *dentry, int *srcu_idx)
+        __acquires(&debugfs_srcu);
+
+void debugfs_use_file_finish(int srcu_idx) __releases(&debugfs_srcu);
+
+ssize_t debugfs_attr_read(struct file *file, char __user *buf,
+                        size_t len, loff_t *ppos);
+ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
+                        size_t len, loff_t *ppos);
+
+#define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt)           \
+static int __fops ## _open(struct inode *inode, struct file *file)      \
+{                                                                       \
+        __simple_attr_check_format(__fmt, 0ull);                        \
+        return simple_attr_open(inode, file, __get, __set, __fmt);      \
+}                                                                       \
+static const struct file_operations __fops = {                          \
+        .owner   = THIS_MODULE,                                 \
+        .open    = __fops ## _open,                                     \
+        .release = simple_attr_release,                         \
+        .read    = debugfs_attr_read,                                   \
+        .write   = debugfs_attr_write,                                  \
+        .llseek  = generic_file_llseek,                         \
+}
+
 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
                 struct dentry *new_dir, const char *new_name);
 
@@ -176,6 +205,20 @@ static inline void debugfs_remove(struct dentry *dentry)
 static inline void debugfs_remove_recursive(struct dentry *dentry)
 { }
 
+static inline int debugfs_use_file_start(const struct dentry *dentry,
+                                        int *srcu_idx)
+        __acquires(&debugfs_srcu)
+{
+        return 0;
+}
+
+static inline void debugfs_use_file_finish(int srcu_idx)
+        __releases(&debugfs_srcu)
+{ }
+
+#define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt)   \
+        static const struct file_operations __fops = { 0 }
+
 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
                 struct dentry *new_dir, char *new_name)
 {
diff --git a/include/linux/devcoredump.h b/include/linux/devcoredump.h
index c0a360e99f64..269521f143ac 100644
--- a/include/linux/devcoredump.h
+++ b/include/linux/devcoredump.h
@@ -1,3 +1,22 @@
+/*
+ * This file is provided under the GPLv2 license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2015 Intel Deutschland GmbH
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * The full GNU General Public License is included in this distribution
+ * in the file called COPYING.
+ */
 #ifndef __DEVCOREDUMP_H
 #define __DEVCOREDUMP_H
 
@@ -5,17 +24,62 @@
 #include <linux/module.h>
 #include <linux/vmalloc.h>
 
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+
+/*
+ * _devcd_free_sgtable - free all the memory of the given scatterlist table
+ * (i.e. both pages and scatterlist instances)
+ * NOTE: if two tables allocated and chained using the sg_chain function then
+ * this function should be called only once on the first table
+ * @table: pointer to sg_table to free
+ */
+static inline void _devcd_free_sgtable(struct scatterlist *table)
+{
+        int i;
+        struct page *page;
+        struct scatterlist *iter;
+        struct scatterlist *delete_iter;
+
+        /* free pages */
+        iter = table;
+        for_each_sg(table, iter, sg_nents(table), i) {
+                page = sg_page(iter);
+                if (page)
+                        __free_page(page);
+        }
+
+        /* then free all chained tables */
+        iter = table;
+        delete_iter = table;    /* always points on a head of a table */
+        while (!sg_is_last(iter)) {
+                iter++;
+                if (sg_is_chain(iter)) {
+                        iter = sg_chain_ptr(iter);
+                        kfree(delete_iter);
+                        delete_iter = iter;
+                }
+        }
+
+        /* free the last table */
+        kfree(delete_iter);
+}
+
+
 #ifdef CONFIG_DEV_COREDUMP
-void dev_coredumpv(struct device *dev, const void *data, size_t datalen,
+void dev_coredumpv(struct device *dev, void *data, size_t datalen,
                    gfp_t gfp);
 
 void dev_coredumpm(struct device *dev, struct module *owner,
-                   const void *data, size_t datalen, gfp_t gfp,
+                   void *data, size_t datalen, gfp_t gfp,
                    ssize_t (*read)(char *buffer, loff_t offset, size_t count,
-                                   const void *data, size_t datalen),
-                   void (*free)(const void *data));
+                                   void *data, size_t datalen),
+                   void (*free)(void *data));
+
+void dev_coredumpsg(struct device *dev, struct scatterlist *table,
+                    size_t datalen, gfp_t gfp);
 #else
-static inline void dev_coredumpv(struct device *dev, const void *data,
+static inline void dev_coredumpv(struct device *dev, void *data,
                                  size_t datalen, gfp_t gfp)
 {
         vfree(data);
@@ -23,13 +87,19 @@ static inline void dev_coredumpv(struct device *dev, const void *data,
 
 static inline void
 dev_coredumpm(struct device *dev, struct module *owner,
-              const void *data, size_t datalen, gfp_t gfp,
+              void *data, size_t datalen, gfp_t gfp,
               ssize_t (*read)(char *buffer, loff_t offset, size_t count,
-                              const void *data, size_t datalen),
-              void (*free)(const void *data))
+                              void *data, size_t datalen),
+              void (*free)(void *data))
 {
         free(data);
 }
+
+static inline void dev_coredumpsg(struct device *dev, struct scatterlist *table,
+                                  size_t datalen, gfp_t gfp)
+{
+        _devcd_free_sgtable(table);
+}
 #endif /* CONFIG_DEV_COREDUMP */
 
 #endif /* __DEVCOREDUMP_H */
diff --git a/include/linux/device.h b/include/linux/device.h
index ca90ad8bcd61..38f02814d53a 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -1288,8 +1288,11 @@ do {									\
                 dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);        \
 } while (0)
 #else
-#define dev_dbg_ratelimited(dev, fmt, ...)                      \
-        no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
+#define dev_dbg_ratelimited(dev, fmt, ...)                              \
+do {                                                                    \
+        if (0)                                                          \
+                dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);        \
+} while (0)
 #endif
 
 #ifdef VERBOSE_DEBUG
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 10d3d8f8a65b..b8b3c72c2aae 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2427,6 +2427,8 @@ static inline void bd_unlink_disk_holder(struct block_device *bdev,
 
 /* fs/char_dev.c */
 #define CHRDEV_MAJOR_HASH_SIZE  255
+/* Marks the bottom of the first segment of free char majors */
+#define CHRDEV_MAJOR_DYN_END 234
 extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
 extern int register_chrdev_region(dev_t, unsigned, const char *);
 extern int __register_chrdev(unsigned int major, unsigned int baseminor,
diff --git a/include/linux/isa.h b/include/linux/isa.h
index b0270e3814c8..5ab85281230b 100644
--- a/include/linux/isa.h
+++ b/include/linux/isa.h
@@ -36,4 +36,36 @@ static inline void isa_unregister_driver(struct isa_driver *d)
 }
 #endif
 
+/**
+ * module_isa_driver() - Helper macro for registering a ISA driver
+ * @__isa_driver: isa_driver struct
+ * @__num_isa_dev: number of devices to register
+ *
+ * Helper macro for ISA drivers which do not do anything special in module
+ * init/exit. This eliminates a lot of boilerplate code. Each module may only
+ * use this macro once, and calling it replaces module_init and module_exit.
+ */
+#define module_isa_driver(__isa_driver, __num_isa_dev) \
+static int __init __isa_driver##_init(void) \
+{ \
+        return isa_register_driver(&(__isa_driver), __num_isa_dev); \
+} \
+module_init(__isa_driver##_init); \
+static void __exit __isa_driver##_exit(void) \
+{ \
+        isa_unregister_driver(&(__isa_driver)); \
+} \
+module_exit(__isa_driver##_exit);
+
+/**
+ * max_num_isa_dev() - Maximum possible number registered of an ISA device
+ * @__ida_dev_ext: ISA device address extent
+ *
+ * The highest base address possible for an ISA device is 0x3FF; this results in
+ * 1024 possible base addresses. Dividing the number of possible base addresses
+ * by the address extent taken by each device results in the maximum number of
+ * devices on a system.
+ */
+#define max_num_isa_dev(__isa_dev_ext) (1024 / __isa_dev_ext)
+
 #endif /* __LINUX_ISA_H */
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index 30f089ebe0a4..96356ef012de 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -179,6 +179,7 @@ struct kernfs_open_file {
 
         /* private fields, do not use outside kernfs proper */
         struct mutex            mutex;
+        struct mutex            prealloc_mutex;
         int                     event;
         struct list_head        list;
         char                    *prealloc_buf;