From 9761536e1d9e9e1f325fb04d4ad46b15a39eb94a Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Mon, 29 Sep 2014 16:08:26 -0700 Subject: debugfs: Have debugfs_print_regs32() return void The seq_printf() will soon just return void, and seq_has_overflowed() should be used instead to see if the seq can no longer accept input. As the return value of debugfs_print_regs32() has no users and the seq_file descriptor should be checked with seq_has_overflowed() instead of return values of functions, it is better to just have debugfs_print_regs32() also return void. Link: http://lkml.kernel.org/p/2634b19eb1c04a9d31148c1fe6f1f3819be95349.1412031505.git.joe@perches.com Acked-by: Greg Kroah-Hartman Signed-off-by: Joe Perches [ original change only updated seq_printf() return, added return of void to debugfs_print_regs32() as well ] Signed-off-by: Steven Rostedt --- include/linux/debugfs.h | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'include/linux/debugfs.h') diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h index 4d0b4d1aa132..d84f8c254a87 100644 --- a/include/linux/debugfs.h +++ b/include/linux/debugfs.h @@ -92,8 +92,8 @@ struct dentry *debugfs_create_regset32(const char *name, umode_t mode, struct dentry *parent, struct debugfs_regset32 *regset); -int debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, - int nregs, void __iomem *base, char *prefix); +void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, + int nregs, void __iomem *base, char *prefix); struct dentry *debugfs_create_u32_array(const char *name, umode_t mode, struct dentry *parent, @@ -233,10 +233,9 @@ static inline struct dentry *debugfs_create_regset32(const char *name, return ERR_PTR(-ENODEV); } -static inline int debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, +static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, int nregs, void __iomem *base, char *prefix) { - return 0; } static inline bool debugfs_initialized(void) -- cgit v1.2.3-71-gd317 From 98210b7f73f1db182bd9a558a031093cd166e907 Mon Sep 17 00:00:00 2001 From: Arend van Spriel Date: Sun, 9 Nov 2014 11:31:58 +0100 Subject: debugfs: add helper function to create device related seq_file This patch adds a helper function that simplifies adding a so-called single_open sequence file for device drivers. The calling device driver needs to provide a read function and a device pointer. The field struct seq_file::private will reference the device pointer upon call to the read function so the driver can obtain his data from it and do its task of providing the file content using seq_printf() calls and alike. Using this helper function also gets rid of the need to specify file operations per debugfs file. Signed-off-by: Arend van Spriel Signed-off-by: Greg Kroah-Hartman --- fs/debugfs/file.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/debugfs.h | 16 ++++++++++++++- 2 files changed, 69 insertions(+), 1 deletion(-) (limited to 'include/linux/debugfs.h') diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index 76c08c2beb2f..a2f8ec70fe8d 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -22,6 +22,7 @@ #include #include #include +#include static ssize_t default_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) @@ -761,3 +762,56 @@ struct dentry *debugfs_create_regset32(const char *name, umode_t mode, EXPORT_SYMBOL_GPL(debugfs_create_regset32); #endif /* CONFIG_HAS_IOMEM */ + +struct debugfs_devm_entry { + int (*read)(struct seq_file *seq, void *data); + struct device *dev; +}; + +static int debugfs_devm_entry_open(struct inode *inode, struct file *f) +{ + struct debugfs_devm_entry *entry = inode->i_private; + + return single_open(f, entry->read, entry->dev); +} + +static const struct file_operations debugfs_devm_entry_ops = { + .owner = THIS_MODULE, + .open = debugfs_devm_entry_open, + .release = single_release, + .read = seq_read, + .llseek = seq_lseek +}; + +/** + * debugfs_create_devm_seqfile - create a debugfs file that is bound to device. + * + * @dev: device related to this debugfs file. + * @name: name of the debugfs file. + * @parent: a pointer to the parent dentry for this file. This should be a + * directory dentry if set. If this parameter is %NULL, then the + * file will be created in the root of the debugfs filesystem. + * @read_fn: function pointer called to print the seq_file content. + */ +struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name, + struct dentry *parent, + int (*read_fn)(struct seq_file *s, + void *data)) +{ + struct debugfs_devm_entry *entry; + + if (IS_ERR(parent)) + return ERR_PTR(-ENOENT); + + entry = devm_kzalloc(dev, sizeof(*entry), GFP_KERNEL); + if (!entry) + return ERR_PTR(-ENOMEM); + + entry->read = read_fn; + entry->dev = dev; + + return debugfs_create_file(name, S_IRUGO, parent, entry, + &debugfs_devm_entry_ops); +} +EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile); + diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h index 4d0b4d1aa132..4bbe2ace972a 100644 --- a/include/linux/debugfs.h +++ b/include/linux/debugfs.h @@ -99,13 +99,18 @@ struct dentry *debugfs_create_u32_array(const char *name, umode_t mode, struct dentry *parent, u32 *array, u32 elements); +struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name, + struct dentry *parent, + int (*read_fn)(struct seq_file *s, + void *data)); + bool debugfs_initialized(void); #else #include -/* +/* * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled * so users have a chance to detect if there was a real error or not. We don't * want to duplicate the design decision mistakes of procfs and devfs again. @@ -251,6 +256,15 @@ static inline struct dentry *debugfs_create_u32_array(const char *name, umode_t return ERR_PTR(-ENODEV); } +static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev, + const char *name, + struct dentry *parent, + int (*read_fn)(struct seq_file *s, + void *data)) +{ + return ERR_PTR(-ENODEV); +} + #endif #endif -- cgit v1.2.3-71-gd317 From f30d0a815bb9b8ac1a3ab4d0c333d2379220d91d Mon Sep 17 00:00:00 2001 From: Arend van Spriel Date: Sun, 30 Nov 2014 16:31:21 +0100 Subject: fs: debugfs: add forward declaration for struct device type The function debugfs_create_devm_seqfile() has a parameter of type struct device pointer. This type needs to be forward declared to avoid compilation issues on certain architectures and/or kernel configurations. The function was introduced with: commit 98210b7f73f1db182bd9a558a031093cd166e907 Author: Arend van Spriel Date: Sun Nov 9 11:31:58 2014 +0100 debugfs: add helper function to create device related seq_file The reported build failure for sparc64 architecture was: make.cross ARCH=sparc64 All warnings: In file included from fs/debugfs/file.c:21:0: include/linux/debugfs.h:105:10: warning: 'struct device' declared inside parameter list void *data)); ^ Reported-by: Fengguang Wu Signed-off-by: Arend van Spriel Signed-off-by: Greg Kroah-Hartman --- include/linux/debugfs.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/debugfs.h') diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h index 4bbe2ace972a..e3e9f31f91d2 100644 --- a/include/linux/debugfs.h +++ b/include/linux/debugfs.h @@ -20,6 +20,7 @@ #include +struct device; struct file_operations; struct debugfs_blob_wrapper { -- cgit v1.2.3-71-gd317