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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#include <linux/slab.h>#include <linux/mutex.h>#include <linux/debugfs.h>#include <linux/uaccess.h>#include <linux/device.h>#include <linux/list.h>#include <linux/idr.h>
#include "internal.h"
struct regmap_debugfs_node { struct regmap *map; struct list_head link;};
static DEFINE_IDA(dummy_ida);static struct dentry *regmap_debugfs_root;static LIST_HEAD(regmap_debugfs_early_list);static DEFINE_MUTEX(regmap_debugfs_early_lock);
/* Calculate the length of a fixed format */static size_t regmap_calc_reg_len(int max_val){ return snprintf(NULL, 0, "%x", max_val);}
static ssize_t regmap_name_read_file(struct file *file, char __user *user_buf, size_t count, loff_t *ppos){ struct regmap *map = file->private_data; const char *name = "nodev"; int ret; char *buf;
buf = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!buf) return -ENOMEM;
if (map->dev && map->dev->driver) name = map->dev->driver->name;
ret = snprintf(buf, PAGE_SIZE, "%s\n", name); if (ret >= PAGE_SIZE) { kfree(buf); return ret; }
ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret); kfree(buf); return ret;}
static const struct file_operations regmap_name_fops = { .open = simple_open, .read = regmap_name_read_file, .llseek = default_llseek,};
static void regmap_debugfs_free_dump_cache(struct regmap *map){ struct regmap_debugfs_off_cache *c;
while (!list_empty(&map->debugfs_off_cache)) { c = list_first_entry(&map->debugfs_off_cache, struct regmap_debugfs_off_cache, list); list_del(&c->list); kfree(c); }}
static bool regmap_printable(struct regmap *map, unsigned int reg){ if (regmap_precious(map, reg)) return false;
if (!regmap_readable(map, reg) && !regmap_cached(map, reg)) return false;
return true;}
/* * Work out where the start offset maps into register numbers, bearing * in mind that we suppress hidden registers. */static unsigned int regmap_debugfs_get_dump_start(struct regmap *map, unsigned int base, loff_t from, loff_t *pos){ struct regmap_debugfs_off_cache *c = NULL; loff_t p = 0; unsigned int i, ret; unsigned int fpos_offset; unsigned int reg_offset;
/* Suppress the cache if we're using a subrange */ if (base) return base;
/* * If we don't have a cache build one so we don't have to do a * linear scan each time. */ mutex_lock(&map->cache_lock); i = base; if (list_empty(&map->debugfs_off_cache)) { for (; i <= map->max_register; i += map->reg_stride) { /* Skip unprinted registers, closing off cache entry */ if (!regmap_printable(map, i)) { if (c) { c->max = p - 1; c->max_reg = i - map->reg_stride; list_add_tail(&c->list, &map->debugfs_off_cache); c = NULL; }
continue; }
/* No cache entry? Start a new one */ if (!c) { c = kzalloc_obj(*c); if (!c) { regmap_debugfs_free_dump_cache(map); mutex_unlock(&map->cache_lock); return base; } c->min = p; c->base_reg = i; }
p += map->debugfs_tot_len; } }
/* Close the last entry off if we didn't scan beyond it */ if (c) { c->max = p - 1; c->max_reg = i - map->reg_stride; list_add_tail(&c->list, &map->debugfs_off_cache); }
/* * This should never happen; we return above if we fail to * allocate and we should never be in this code if there are * no registers at all. */ WARN_ON(list_empty(&map->debugfs_off_cache)); ret = base;
/* Find the relevant block:offset */ list_for_each_entry(c, &map->debugfs_off_cache, list) { if (from >= c->min && from <= c->max) { fpos_offset = from - c->min; reg_offset = fpos_offset / map->debugfs_tot_len; *pos = c->min + (reg_offset * map->debugfs_tot_len); mutex_unlock(&map->cache_lock); return c->base_reg + (reg_offset * map->reg_stride); }
*pos = c->max; ret = c->max_reg; } mutex_unlock(&map->cache_lock);
return ret;}
static inline void regmap_calc_tot_len(struct regmap *map, void *buf, size_t count){ /* Calculate the length of a fixed format */ if (!map->debugfs_tot_len) { map->debugfs_reg_len = regmap_calc_reg_len(map->max_register); map->debugfs_val_len = 2 * map->format.val_bytes; map->debugfs_tot_len = map->debugfs_reg_len + map->debugfs_val_len + 3; /* : \n */ }}
static int regmap_next_readable_reg(struct regmap *map, int reg){ struct regmap_debugfs_off_cache *c; int ret = -EINVAL;
if (regmap_printable(map, reg + map->reg_stride)) { ret = reg + map->reg_stride; } else { mutex_lock(&map->cache_lock); list_for_each_entry(c, &map->debugfs_off_cache, list) { if (reg > c->max_reg) continue; if (reg < c->base_reg) { ret = c->base_reg; break; } } mutex_unlock(&map->cache_lock); } return ret;}
static ssize_t regmap_read_debugfs(struct regmap *map, unsigned int from, unsigned int to, char __user *user_buf, size_t count, loff_t *ppos){ size_t buf_pos = 0; loff_t p = *ppos; ssize_t ret; int i; char *buf; unsigned int val, start_reg;
if (*ppos < 0 || !count) return -EINVAL;
if (count > (PAGE_SIZE << MAX_PAGE_ORDER)) count = PAGE_SIZE << MAX_PAGE_ORDER;
buf = kmalloc(count, GFP_KERNEL); if (!buf) return -ENOMEM;
regmap_calc_tot_len(map, buf, count);
/* Work out which register we're starting at */ start_reg = regmap_debugfs_get_dump_start(map, from, *ppos, &p);
for (i = start_reg; i >= 0 && i <= to; i = regmap_next_readable_reg(map, i)) {
/* If we're in the region the user is trying to read */ if (p >= *ppos) { /* ...but not beyond it */ if (buf_pos + map->debugfs_tot_len > count) break;
/* Format the register */ snprintf(buf + buf_pos, count - buf_pos, "%.*x: ", map->debugfs_reg_len, i - from); buf_pos += map->debugfs_reg_len + 2;
/* Format the value, write all X if we can't read */ ret = regmap_read(map, i, &val); if (ret == 0) snprintf(buf + buf_pos, count - buf_pos, "%.*x", map->debugfs_val_len, val); else memset(buf + buf_pos, 'X', map->debugfs_val_len); buf_pos += 2 * map->format.val_bytes;
buf[buf_pos++] = '\n'; } p += map->debugfs_tot_len; }
ret = buf_pos;
if (copy_to_user(user_buf, buf, buf_pos)) { ret = -EFAULT; goto out; }
*ppos += buf_pos;
out: kfree(buf); return ret;}
static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf, size_t count, loff_t *ppos){ struct regmap *map = file->private_data;
return regmap_read_debugfs(map, 0, map->max_register, user_buf, count, ppos);}
#undef REGMAP_ALLOW_WRITE_DEBUGFS#ifdef REGMAP_ALLOW_WRITE_DEBUGFS/* * This can be dangerous especially when we have clients such as * PMICs, therefore don't provide any real compile time configuration option * for this feature, people who want to use this will need to modify * the source code directly. */static ssize_t regmap_map_write_file(struct file *file, const char __user *user_buf, size_t count, loff_t *ppos){ char buf[32]; size_t buf_size; char *start = buf; unsigned long reg, value; struct regmap *map = file->private_data; int ret;
buf_size = min(count, (sizeof(buf)-1)); if (copy_from_user(buf, user_buf, buf_size)) return -EFAULT; buf[buf_size] = 0;
while (*start == ' ') start++; reg = simple_strtoul(start, &start, 16); while (*start == ' ') start++; if (kstrtoul(start, 16, &value)) return -EINVAL;
/* Userspace has been fiddling around behind the kernel's back */ add_taint(TAINT_USER, LOCKDEP_STILL_OK);
ret = regmap_write(map, reg, value); if (ret < 0) return ret; return buf_size;}#else#define regmap_map_write_file NULL#endif
static const struct file_operations regmap_map_fops = { .open = simple_open, .read = regmap_map_read_file, .write = regmap_map_write_file, .llseek = default_llseek,};
static ssize_t regmap_range_read_file(struct file *file, char __user *user_buf, size_t count, loff_t *ppos){ struct regmap_range_node *range = file->private_data; struct regmap *map = range->map;
return regmap_read_debugfs(map, range->range_min, range->range_max, user_buf, count, ppos);}
static const struct file_operations regmap_range_fops = { .open = simple_open, .read = regmap_range_read_file, .llseek = default_llseek,};
static ssize_t regmap_reg_ranges_read_file(struct file *file, char __user *user_buf, size_t count, loff_t *ppos){ struct regmap *map = file->private_data; struct regmap_debugfs_off_cache *c; loff_t p = 0; size_t buf_pos = 0; char *buf; char *entry; int ret; unsigned int entry_len;
if (*ppos < 0 || !count) return -EINVAL;
if (count > (PAGE_SIZE << MAX_PAGE_ORDER)) count = PAGE_SIZE << MAX_PAGE_ORDER;
buf = kmalloc(count, GFP_KERNEL); if (!buf) return -ENOMEM;
entry = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!entry) { kfree(buf); return -ENOMEM; }
/* While we are at it, build the register dump cache * now so the read() operation on the `registers' file * can benefit from using the cache. We do not care * about the file position information that is contained * in the cache, just about the actual register blocks */ regmap_calc_tot_len(map, buf, count); regmap_debugfs_get_dump_start(map, 0, *ppos, &p);
/* Reset file pointer as the fixed-format of the `registers' * file is not compatible with the `range' file */ p = 0; mutex_lock(&map->cache_lock); list_for_each_entry(c, &map->debugfs_off_cache, list) { entry_len = snprintf(entry, PAGE_SIZE, "%x-%x\n", c->base_reg, c->max_reg); if (p >= *ppos) { if (buf_pos + entry_len > count) break; memcpy(buf + buf_pos, entry, entry_len); buf_pos += entry_len; } p += entry_len; } mutex_unlock(&map->cache_lock);
kfree(entry); ret = buf_pos;
if (copy_to_user(user_buf, buf, buf_pos)) { ret = -EFAULT; goto out_buf; }
*ppos += buf_pos;out_buf: kfree(buf); return ret;}
static const struct file_operations regmap_reg_ranges_fops = { .open = simple_open, .read = regmap_reg_ranges_read_file, .llseek = default_llseek,};
static int regmap_access_show(struct seq_file *s, void *ignored){ struct regmap *map = s->private; int i, reg_len;
reg_len = regmap_calc_reg_len(map->max_register);
for (i = 0; i <= map->max_register; i += map->reg_stride) { /* Ignore registers which are neither readable nor writable */ if (!regmap_readable(map, i) && !regmap_writeable(map, i)) continue;
/* Format the register */ seq_printf(s, "%.*x: %c %c %c %c\n", reg_len, i, regmap_readable(map, i) ? 'y' : 'n', regmap_writeable(map, i) ? 'y' : 'n', regmap_volatile(map, i) ? 'y' : 'n', regmap_precious(map, i) ? 'y' : 'n'); }
return 0;}
DEFINE_SHOW_ATTRIBUTE(regmap_access);
static ssize_t regmap_cache_only_write_file(struct file *file, const char __user *user_buf, size_t count, loff_t *ppos){ struct regmap *map = container_of(file->private_data, struct regmap, cache_only); bool new_val, require_sync = false; int err;
err = kstrtobool_from_user(user_buf, count, &new_val); /* Ignore malforned data like debugfs_write_file_bool() */ if (err) return count;
map->lock(map->lock_arg);
if (new_val && !map->cache_only) { dev_warn(map->dev, "debugfs cache_only=Y forced\n"); add_taint(TAINT_USER, LOCKDEP_STILL_OK); } else if (!new_val && map->cache_only) { dev_warn(map->dev, "debugfs cache_only=N forced: syncing cache\n"); require_sync = true; } map->cache_only = new_val;
map->unlock(map->lock_arg);
if (require_sync) { err = regcache_sync(map); if (err) dev_err(map->dev, "Failed to sync cache %d\n", err); }
return count;}
static const struct file_operations regmap_cache_only_fops = { .open = simple_open, .read = debugfs_read_file_bool, .write = regmap_cache_only_write_file,};
static ssize_t regmap_cache_bypass_write_file(struct file *file, const char __user *user_buf, size_t count, loff_t *ppos){ struct regmap *map = container_of(file->private_data, struct regmap, cache_bypass); bool new_val; int err;
err = kstrtobool_from_user(user_buf, count, &new_val); /* Ignore malforned data like debugfs_write_file_bool() */ if (err) return count;
map->lock(map->lock_arg);
if (new_val && !map->cache_bypass) { dev_warn(map->dev, "debugfs cache_bypass=Y forced\n"); add_taint(TAINT_USER, LOCKDEP_STILL_OK); } else if (!new_val && map->cache_bypass) { dev_warn(map->dev, "debugfs cache_bypass=N forced\n"); } map->cache_bypass = new_val;
map->unlock(map->lock_arg);
return count;}
static const struct file_operations regmap_cache_bypass_fops = { .open = simple_open, .read = debugfs_read_file_bool, .write = regmap_cache_bypass_write_file,};
void regmap_debugfs_init(struct regmap *map){ struct rb_node *next; struct regmap_range_node *range_node; const char *devname = "dummy"; const char *name = map->name; int id;
/* * Userspace can initiate reads from the hardware over debugfs. * Normally internal regmap structures and buffers are protected with * a mutex or a spinlock, but if the regmap owner decided to disable * all locking mechanisms, this is no longer the case. For safety: * don't create the debugfs entries if locking is disabled. */ if (map->debugfs_disable) { dev_dbg(map->dev, "regmap locking disabled - not creating debugfs entries\n"); return; }
/* If we don't have the debugfs root yet, postpone init */ if (!regmap_debugfs_root) { struct regmap_debugfs_node *node; node = kzalloc_obj(*node); if (!node) return; node->map = map; mutex_lock(®map_debugfs_early_lock); list_add(&node->link, ®map_debugfs_early_list); mutex_unlock(®map_debugfs_early_lock); return; }
INIT_LIST_HEAD(&map->debugfs_off_cache); mutex_init(&map->cache_lock); map->debugfs_dummy_id = -1;
if (map->dev) devname = dev_name(map->dev);
if (name) { if (!map->debugfs_name) { map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s", devname, name); if (!map->debugfs_name) return; } name = map->debugfs_name; } else { name = devname; }
if (!strcmp(name, "dummy")) { kfree(map->debugfs_name); id = ida_alloc(&dummy_ida, GFP_KERNEL); if (id < 0) return; map->debugfs_name = kasprintf(GFP_KERNEL, "dummy%d", id); if (!map->debugfs_name) { ida_free(&dummy_ida, id); return; } map->debugfs_dummy_id = id; name = map->debugfs_name; }
map->debugfs = debugfs_create_dir(name, regmap_debugfs_root);
debugfs_create_file("name", 0400, map->debugfs, map, ®map_name_fops);
debugfs_create_file("range", 0400, map->debugfs, map, ®map_reg_ranges_fops);
if (map->max_register || regmap_readable(map, 0)) { umode_t registers_mode;
#if defined(REGMAP_ALLOW_WRITE_DEBUGFS) registers_mode = 0600;#else registers_mode = 0400;#endif
debugfs_create_file("registers", registers_mode, map->debugfs, map, ®map_map_fops); debugfs_create_file("access", 0400, map->debugfs, map, ®map_access_fops); }
if (map->cache_type) { debugfs_create_file("cache_only", 0600, map->debugfs, &map->cache_only, ®map_cache_only_fops); debugfs_create_bool("cache_dirty", 0400, map->debugfs, &map->cache_dirty); debugfs_create_file("cache_bypass", 0600, map->debugfs, &map->cache_bypass, ®map_cache_bypass_fops); }
/* * This could interfere with driver operation. Therefore, don't provide * any real compile time configuration option for this feature. One will * have to modify the source code directly in order to use it. */#undef REGMAP_ALLOW_FORCE_WRITE_FIELD_DEBUGFS#ifdef REGMAP_ALLOW_FORCE_WRITE_FIELD_DEBUGFS debugfs_create_bool("force_write_field", 0600, map->debugfs, &map->force_write_field);#endif
next = rb_first(&map->range_tree); while (next) { range_node = rb_entry(next, struct regmap_range_node, node);
if (range_node->name) debugfs_create_file(range_node->name, 0400, map->debugfs, range_node, ®map_range_fops);
next = rb_next(&range_node->node); }
if (map->cache_ops && map->cache_ops->debugfs_init) map->cache_ops->debugfs_init(map);}
void regmap_debugfs_exit(struct regmap *map){ if (map->debugfs) { debugfs_remove_recursive(map->debugfs); mutex_lock(&map->cache_lock); regmap_debugfs_free_dump_cache(map); mutex_unlock(&map->cache_lock); if (map->debugfs_dummy_id >= 0) { ida_free(&dummy_ida, map->debugfs_dummy_id); map->debugfs_dummy_id = -1; } kfree(map->debugfs_name); map->debugfs_name = NULL; } else { struct regmap_debugfs_node *node, *tmp;
mutex_lock(®map_debugfs_early_lock); list_for_each_entry_safe(node, tmp, ®map_debugfs_early_list, link) { if (node->map == map) { list_del(&node->link); kfree(node); } } mutex_unlock(®map_debugfs_early_lock); }}
void regmap_debugfs_initcall(void){ struct regmap_debugfs_node *node, *tmp;
regmap_debugfs_root = debugfs_create_dir("regmap", NULL);
mutex_lock(®map_debugfs_early_lock); list_for_each_entry_safe(node, tmp, ®map_debugfs_early_list, link) { regmap_debugfs_init(node->map); list_del(&node->link); kfree(node); } mutex_unlock(®map_debugfs_early_lock);}