diff options
Diffstat (limited to 'drivers/clk/clk.c')
| -rw-r--r-- | drivers/clk/clk.c | 95 |
1 files changed, 81 insertions, 14 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index f467d63bbf1e..8de6a22498e7 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -424,19 +424,20 @@ static void clk_core_fill_parent_index(struct clk_core *core, u8 index) if (entry->hw) { parent = entry->hw->core; - /* - * We have a direct reference but it isn't registered yet? - * Orphan it and let clk_reparent() update the orphan status - * when the parent is registered. - */ - if (!parent) - parent = ERR_PTR(-EPROBE_DEFER); } else { parent = clk_core_get(core, index); if (PTR_ERR(parent) == -ENOENT && entry->name) parent = clk_core_lookup(entry->name); } + /* + * We have a direct reference but it isn't registered yet? + * Orphan it and let clk_reparent() update the orphan status + * when the parent is registered. + */ + if (!parent) + parent = ERR_PTR(-EPROBE_DEFER); + /* Only cache it if it's not an error */ if (!IS_ERR(parent)) entry->core = parent; @@ -2965,7 +2966,9 @@ static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c, { struct clk_core *child; + clk_pm_runtime_get(c); clk_summary_show_one(s, c, level); + clk_pm_runtime_put(c); hlist_for_each_entry(child, &c->children, child_node) clk_summary_show_subtree(s, child, level + 1); @@ -3217,6 +3220,42 @@ static int current_parent_show(struct seq_file *s, void *data) } DEFINE_SHOW_ATTRIBUTE(current_parent); +#ifdef CLOCK_ALLOW_WRITE_DEBUGFS +static ssize_t current_parent_write(struct file *file, const char __user *ubuf, + size_t count, loff_t *ppos) +{ + struct seq_file *s = file->private_data; + struct clk_core *core = s->private; + struct clk_core *parent; + u8 idx; + int err; + + err = kstrtou8_from_user(ubuf, count, 0, &idx); + if (err < 0) + return err; + + parent = clk_core_get_parent_by_index(core, idx); + if (!parent) + return -ENOENT; + + clk_prepare_lock(); + err = clk_core_set_parent_nolock(core, parent); + clk_prepare_unlock(); + if (err) + return err; + + return count; +} + +static const struct file_operations current_parent_rw_fops = { + .open = current_parent_open, + .write = current_parent_write, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; +#endif + static int clk_duty_cycle_show(struct seq_file *s, void *data) { struct clk_core *core = s->private; @@ -3282,8 +3321,12 @@ static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry) #ifdef CLOCK_ALLOW_WRITE_DEBUGFS debugfs_create_file("clk_prepare_enable", 0644, root, core, &clk_prepare_enable_fops); -#endif + if (core->num_parents > 1) + debugfs_create_file("clk_parent", 0644, root, core, + ¤t_parent_rw_fops); + else +#endif if (core->num_parents > 0) debugfs_create_file("clk_parent", 0444, root, core, ¤t_parent_fops); @@ -3343,6 +3386,24 @@ static int __init clk_debug_init(void) { struct clk_core *core; +#ifdef CLOCK_ALLOW_WRITE_DEBUGFS + pr_warn("\n"); + pr_warn("********************************************************************\n"); + pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); + pr_warn("** **\n"); + pr_warn("** WRITEABLE clk DebugFS SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n"); + pr_warn("** **\n"); + pr_warn("** This means that this kernel is built to expose clk operations **\n"); + pr_warn("** such as parent or rate setting, enabling, disabling, etc. **\n"); + pr_warn("** to userspace, which may compromise security on your system. **\n"); + pr_warn("** **\n"); + pr_warn("** If you see this message and you are not debugging the **\n"); + pr_warn("** kernel, report this immediately to your vendor! **\n"); + pr_warn("** **\n"); + pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); + pr_warn("********************************************************************\n"); +#endif + rootdir = debugfs_create_dir("clk", NULL); debugfs_create_file("clk_summary", 0444, rootdir, &all_lists, @@ -3413,11 +3474,16 @@ static int __clk_core_init(struct clk_core *core) unsigned long rate; int phase; - if (!core) - return -EINVAL; - clk_prepare_lock(); + /* + * Set hw->core after grabbing the prepare_lock to synchronize with + * callers of clk_core_fill_parent_index() where we treat hw->core + * being NULL as the clk not being registered yet. This is crucial so + * that clks aren't parented until their parent is fully registered. + */ + core->hw->core = core; + ret = clk_pm_runtime_get(core); if (ret) goto unlock; @@ -3582,8 +3648,10 @@ static int __clk_core_init(struct clk_core *core) out: clk_pm_runtime_put(core); unlock: - if (ret) + if (ret) { hlist_del_init(&core->child_node); + core->hw->core = NULL; + } clk_prepare_unlock(); @@ -3847,7 +3915,6 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw) core->num_parents = init->num_parents; core->min_rate = 0; core->max_rate = ULONG_MAX; - hw->core = core; ret = clk_core_populate_parent_map(core, init); if (ret) @@ -3865,7 +3932,7 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw) goto fail_create_clk; } - clk_core_link_consumer(hw->core, hw->clk); + clk_core_link_consumer(core, hw->clk); ret = __clk_core_init(core); if (!ret) |