[PATCH RFC 1/4] Debugfs support for reading an array of u32-type integers
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From: Srivatsa Vaddagiri on 26 Jul 2010 02:20 Debugfs support for reading an array of u32-type integers. This is a rework of what code already exists for Xen. Signed-off-by: Srivatsa Vaddagiri <vatsa(a)linux.vnet.ibm.com> --- arch/x86/xen/debugfs.c | 104 ---------------------------------------- arch/x86/xen/debugfs.h | 4 - arch/x86/xen/mmu.c | 2 arch/x86/xen/multicalls.c | 6 +- arch/x86/xen/spinlock.c | 6 +- fs/debugfs/file.c | 117 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/debugfs.h | 11 ++++ 7 files changed, 135 insertions(+), 115 deletions(-) Index: current/arch/x86/xen/debugfs.c =================================================================== --- current.orig/arch/x86/xen/debugfs.c +++ current/arch/x86/xen/debugfs.c @@ -18,107 +18,3 @@ struct dentry * __init xen_init_debugfs( return d_xen_debug; } - -struct array_data -{ - void *array; - unsigned elements; -}; - -static int u32_array_open(struct inode *inode, struct file *file) -{ - file->private_data = NULL; - return nonseekable_open(inode, file); -} - -static size_t format_array(char *buf, size_t bufsize, const char *fmt, - u32 *array, unsigned array_size) -{ - size_t ret = 0; - unsigned i; - - for(i = 0; i < array_size; i++) { - size_t len; - - len = snprintf(buf, bufsize, fmt, array[i]); - len++; /* ' ' or '\n' */ - ret += len; - - if (buf) { - buf += len; - bufsize -= len; - buf[-1] = (i == array_size-1) ? '\n' : ' '; - } - } - - ret++; /* \0 */ - if (buf) - *buf = '\0'; - - return ret; -} - -static char *format_array_alloc(const char *fmt, u32 *array, unsigned array_size) -{ - size_t len = format_array(NULL, 0, fmt, array, array_size); - char *ret; - - ret = kmalloc(len, GFP_KERNEL); - if (ret == NULL) - return NULL; - - format_array(ret, len, fmt, array, array_size); - return ret; -} - -static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len, - loff_t *ppos) -{ - struct inode *inode = file->f_path.dentry->d_inode; - struct array_data *data = inode->i_private; - size_t size; - - if (*ppos == 0) { - if (file->private_data) { - kfree(file->private_data); - file->private_data = NULL; - } - - file->private_data = format_array_alloc("%u", data->array, data->elements); - } - - size = 0; - if (file->private_data) - size = strlen(file->private_data); - - return simple_read_from_buffer(buf, len, ppos, file->private_data, size); -} - -static int xen_array_release(struct inode *inode, struct file *file) -{ - kfree(file->private_data); - - return 0; -} - -static const struct file_operations u32_array_fops = { - .owner = THIS_MODULE, - .open = u32_array_open, - .release= xen_array_release, - .read = u32_array_read, -}; - -struct dentry *xen_debugfs_create_u32_array(const char *name, mode_t mode, - struct dentry *parent, - u32 *array, unsigned elements) -{ - struct array_data *data = kmalloc(sizeof(*data), GFP_KERNEL); - - if (data == NULL) - return NULL; - - data->array = array; - data->elements = elements; - - return debugfs_create_file(name, mode, parent, data, &u32_array_fops); -} Index: current/arch/x86/xen/debugfs.h =================================================================== --- current.orig/arch/x86/xen/debugfs.h +++ current/arch/x86/xen/debugfs.h @@ -3,8 +3,4 @@ struct dentry * __init xen_init_debugfs(void); -struct dentry *xen_debugfs_create_u32_array(const char *name, mode_t mode, - struct dentry *parent, - u32 *array, unsigned elements); - #endif /* _XEN_DEBUGFS_H */ Index: current/arch/x86/xen/mmu.c =================================================================== --- current.orig/arch/x86/xen/mmu.c +++ current/arch/x86/xen/mmu.c @@ -1983,7 +1983,7 @@ static int __init xen_mmu_debugfs(void) debugfs_create_u32("mmu_update", 0444, d_mmu_debug, &mmu_stats.mmu_update); debugfs_create_u32("mmu_update_extended", 0444, d_mmu_debug, &mmu_stats.mmu_update_extended); - xen_debugfs_create_u32_array("mmu_update_histo", 0444, d_mmu_debug, + debugfs_create_u32_array("mmu_update_histo", 0444, d_mmu_debug, mmu_stats.mmu_update_histo, 20); debugfs_create_u32("set_pte_at", 0444, d_mmu_debug, &mmu_stats.set_pte_at); Index: current/arch/x86/xen/multicalls.c =================================================================== --- current.orig/arch/x86/xen/multicalls.c +++ current/arch/x86/xen/multicalls.c @@ -269,11 +269,11 @@ static int __init xen_mc_debugfs(void) debugfs_create_u32("hypercalls", 0444, d_mc_debug, &mc_stats.hypercalls); debugfs_create_u32("arg_total", 0444, d_mc_debug, &mc_stats.arg_total); - xen_debugfs_create_u32_array("batch_histo", 0444, d_mc_debug, + debugfs_create_u32_array("batch_histo", 0444, d_mc_debug, mc_stats.histo, MC_BATCH); - xen_debugfs_create_u32_array("hypercall_histo", 0444, d_mc_debug, + debugfs_create_u32_array("hypercall_histo", 0444, d_mc_debug, mc_stats.histo_hypercalls, NHYPERCALLS); - xen_debugfs_create_u32_array("flush_reasons", 0444, d_mc_debug, + debugfs_create_u32_array("flush_reasons", 0444, d_mc_debug, mc_stats.flush, FL_N_REASONS); return 0; Index: current/arch/x86/xen/spinlock.c =================================================================== --- current.orig/arch/x86/xen/spinlock.c +++ current/arch/x86/xen/spinlock.c @@ -423,11 +423,11 @@ static int __init xen_spinlock_debugfs(v debugfs_create_u64("time_total", 0444, d_spin_debug, &spinlock_stats.time_total); - xen_debugfs_create_u32_array("histo_total", 0444, d_spin_debug, + debugfs_create_u32_array("histo_total", 0444, d_spin_debug, spinlock_stats.histo_spin_total, HISTO_BUCKETS + 1); - xen_debugfs_create_u32_array("histo_spinning", 0444, d_spin_debug, + debugfs_create_u32_array("histo_spinning", 0444, d_spin_debug, spinlock_stats.histo_spin_spinning, HISTO_BUCKETS + 1); - xen_debugfs_create_u32_array("histo_blocked", 0444, d_spin_debug, + debugfs_create_u32_array("histo_blocked", 0444, d_spin_debug, spinlock_stats.histo_spin_blocked, HISTO_BUCKETS + 1); return 0; Index: current/fs/debugfs/file.c =================================================================== --- current.orig/fs/debugfs/file.c +++ current/fs/debugfs/file.c @@ -18,6 +18,7 @@ #include <linux/pagemap.h> #include <linux/namei.h> #include <linux/debugfs.h> +#include <linux/slab.h> static ssize_t default_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) @@ -531,3 +532,119 @@ struct dentry *debugfs_create_blob(const return debugfs_create_file(name, mode, parent, blob, &fops_blob); } EXPORT_SYMBOL_GPL(debugfs_create_blob); + +struct array_data { + void *array; + unsigned elements; +}; + +static int u32_array_open(struct inode *inode, struct file *file) +{ + file->private_data = NULL; + return nonseekable_open(inode, file); +} + +static size_t format_array(char *buf, size_t bufsize, const char *fmt, + u32 *array, unsigned array_size) +{ + size_t ret = 0; + unsigned i; + + for (i = 0; i < array_size; i++) { + size_t len; + + len = snprintf(buf, bufsize, fmt, array[i]); + len++; /* ' ' or '\n' */ + ret += len; + + if (buf) { + buf += len; + bufsize -= len; + buf[-1] = (i == array_size-1) ? '\n' : ' '; + } + } + + ret++; /* \0 */ + if (buf) + *buf = '\0'; + + return ret; +} + +static char * +format_array_alloc(const char *fmt, u32 *array, unsigned array_size) +{ + size_t len = format_array(NULL, 0, fmt, array, array_size); + char *ret; + + ret = kmalloc(len, GFP_KERNEL); + if (ret == NULL) + return NULL; + + format_array(ret, len, fmt, array, array_size); + return ret; +} + +static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len, + loff_t *ppos) +{ + struct inode *inode = file->f_path.dentry->d_inode; + struct array_data *data = inode->i_private; + size_t size; + + if (*ppos == 0) { + kfree(file->private_data); + file->private_data = format_array_alloc("%u", data->array, + data->elements); + } + + size = 0; + if (file->private_data) + size = strlen(file->private_data); + + return simple_read_from_buffer(buf, len, ppos, + file->private_data, size); +} + +static int u32_array_release(struct inode *inode, struct file *file) +{ + kfree(file->private_data); + + return 0; +} + +static const struct file_operations u32_array_fops = { + .owner = THIS_MODULE, + .open = u32_array_open, + .release = u32_array_release, + .read = u32_array_read, +}; + +/** + * debugfs_create_u32_array - create a debugfs file that is used to read an array of unsigned 32-bit values. + * @name: a pointer to a string containing the name of the file to create. + * @mode: the permission that the file should have + * @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. + * @array: array of integers of type u32 + * @elements: number of elements in the array + */ +struct dentry *debugfs_create_u32_array(const char *name, mode_t mode, + struct dentry *parent, + u32 *array, unsigned elements) +{ + struct array_data *data = kmalloc(sizeof(*data), GFP_KERNEL); + + if (data == NULL) + return NULL; + + /* u32 array can't be written or executed! */ + if (mode & (S_IWUGO | S_IXUGO)) + return ERR_PTR(-EINVAL); + + data->array = array; + data->elements = elements; + + return debugfs_create_file(name, mode, parent, data, &u32_array_fops); +} Index: current/include/linux/debugfs.h =================================================================== --- current.orig/include/linux/debugfs.h +++ current/include/linux/debugfs.h @@ -74,6 +74,10 @@ struct dentry *debugfs_create_blob(const struct dentry *parent, struct debugfs_blob_wrapper *blob); +struct dentry *debugfs_create_u32_array(const char *name, mode_t mode, + struct dentry *parent, + u32 *array, unsigned elements); + bool debugfs_initialized(void); #else @@ -188,6 +192,13 @@ static inline struct dentry *debugfs_cre return ERR_PTR(-ENODEV); } +struct dentry *debugfs_create_u32_array(const char *name, mode_t mode, + struct dentry *parent, + u32 *array, unsigned elements) +{ + return ERR_PTR(-ENODEV); +} + static inline bool debugfs_initialized(void) { return false; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |