diff options
Diffstat (limited to 'drivers/clk/clk.c')
| -rw-r--r-- | drivers/clk/clk.c | 620 |
1 files changed, 522 insertions, 98 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index b56c11f51baf..0f686a9dac3e 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -24,6 +24,7 @@ #include <linux/pm_runtime.h> #include <linux/sched.h> #include <linux/clkdev.h> +#include <linux/stringify.h> #include "clk.h" @@ -62,6 +63,7 @@ struct clk_core { bool orphan; unsigned int enable_count; unsigned int prepare_count; + unsigned int protect_count; unsigned long min_rate; unsigned long max_rate; unsigned long accuracy; @@ -86,6 +88,7 @@ struct clk { const char *con_id; unsigned long min_rate; unsigned long max_rate; + unsigned int exclusive_count; struct hlist_node clks_node; }; @@ -141,10 +144,18 @@ static unsigned long clk_enable_lock(void) { unsigned long flags; - if (!spin_trylock_irqsave(&enable_lock, flags)) { + /* + * On UP systems, spin_trylock_irqsave() always returns true, even if + * we already hold the lock. So, in that case, we rely only on + * reference counting. + */ + if (!IS_ENABLED(CONFIG_SMP) || + !spin_trylock_irqsave(&enable_lock, flags)) { if (enable_owner == current) { enable_refcnt++; __acquire(enable_lock); + if (!IS_ENABLED(CONFIG_SMP)) + local_save_flags(flags); return flags; } spin_lock_irqsave(&enable_lock, flags); @@ -170,6 +181,11 @@ static void clk_enable_unlock(unsigned long flags) spin_unlock_irqrestore(&enable_lock, flags); } +static bool clk_core_rate_is_protected(struct clk_core *core) +{ + return core->protect_count; +} + static bool clk_core_is_prepared(struct clk_core *core) { bool ret = false; @@ -382,6 +398,11 @@ bool clk_hw_is_prepared(const struct clk_hw *hw) return clk_core_is_prepared(hw->core); } +bool clk_hw_rate_is_protected(const struct clk_hw *hw) +{ + return clk_core_rate_is_protected(hw->core); +} + bool clk_hw_is_enabled(const struct clk_hw *hw) { return clk_core_is_enabled(hw->core); @@ -520,6 +541,139 @@ EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest); /*** clk api ***/ +static void clk_core_rate_unprotect(struct clk_core *core) +{ + lockdep_assert_held(&prepare_lock); + + if (!core) + return; + + if (WARN_ON(core->protect_count == 0)) + return; + + if (--core->protect_count > 0) + return; + + clk_core_rate_unprotect(core->parent); +} + +static int clk_core_rate_nuke_protect(struct clk_core *core) +{ + int ret; + + lockdep_assert_held(&prepare_lock); + + if (!core) + return -EINVAL; + + if (core->protect_count == 0) + return 0; + + ret = core->protect_count; + core->protect_count = 1; + clk_core_rate_unprotect(core); + + return ret; +} + +/** + * clk_rate_exclusive_put - release exclusivity over clock rate control + * @clk: the clk over which the exclusivity is released + * + * clk_rate_exclusive_put() completes a critical section during which a clock + * consumer cannot tolerate any other consumer making any operation on the + * clock which could result in a rate change or rate glitch. Exclusive clocks + * cannot have their rate changed, either directly or indirectly due to changes + * further up the parent chain of clocks. As a result, clocks up parent chain + * also get under exclusive control of the calling consumer. + * + * If exlusivity is claimed more than once on clock, even by the same consumer, + * the rate effectively gets locked as exclusivity can't be preempted. + * + * Calls to clk_rate_exclusive_put() must be balanced with calls to + * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return + * error status. + */ +void clk_rate_exclusive_put(struct clk *clk) +{ + if (!clk) + return; + + clk_prepare_lock(); + + /* + * if there is something wrong with this consumer protect count, stop + * here before messing with the provider + */ + if (WARN_ON(clk->exclusive_count <= 0)) + goto out; + + clk_core_rate_unprotect(clk->core); + clk->exclusive_count--; +out: + clk_prepare_unlock(); +} +EXPORT_SYMBOL_GPL(clk_rate_exclusive_put); + +static void clk_core_rate_protect(struct clk_core *core) +{ + lockdep_assert_held(&prepare_lock); + + if (!core) + return; + + if (core->protect_count == 0) + clk_core_rate_protect(core->parent); + + core->protect_count++; +} + +static void clk_core_rate_restore_protect(struct clk_core *core, int count) +{ + lockdep_assert_held(&prepare_lock); + + if (!core) + return; + + if (count == 0) + return; + + clk_core_rate_protect(core); + core->protect_count = count; +} + +/** + * clk_rate_exclusive_get - get exclusivity over the clk rate control + * @clk: the clk over which the exclusity of rate control is requested + * + * clk_rate_exlusive_get() begins a critical section during which a clock + * consumer cannot tolerate any other consumer making any operation on the + * clock which could result in a rate change or rate glitch. Exclusive clocks + * cannot have their rate changed, either directly or indirectly due to changes + * further up the parent chain of clocks. As a result, clocks up parent chain + * also get under exclusive control of the calling consumer. + * + * If exlusivity is claimed more than once on clock, even by the same consumer, + * the rate effectively gets locked as exclusivity can't be preempted. + * + * Calls to clk_rate_exclusive_get() should be balanced with calls to + * clk_rate_exclusive_put(). Calls to this function may sleep. + * Returns 0 on success, -EERROR otherwise + */ +int clk_rate_exclusive_get(struct clk *clk) +{ + if (!clk) + return 0; + + clk_prepare_lock(); + clk_core_rate_protect(clk->core); + clk->exclusive_count++; + clk_prepare_unlock(); + + return 0; +} +EXPORT_SYMBOL_GPL(clk_rate_exclusive_get); + static void clk_core_unprepare(struct clk_core *core) { lockdep_assert_held(&prepare_lock); @@ -906,10 +1060,9 @@ static int clk_disable_unused(void) } late_initcall_sync(clk_disable_unused); -static int clk_core_round_rate_nolock(struct clk_core *core, - struct clk_rate_request *req) +static int clk_core_determine_round_nolock(struct clk_core *core, + struct clk_rate_request *req) { - struct clk_core *parent; long rate; lockdep_assert_held(&prepare_lock); @@ -917,16 +1070,15 @@ static int clk_core_round_rate_nolock(struct clk_core *core, if (!core) return 0; - parent = core->parent; - if (parent) { - req->best_parent_hw = parent->hw; - req->best_parent_rate = parent->rate; - } else { - req->best_parent_hw = NULL; - req->best_parent_rate = 0; - } - - if (core->ops->determine_rate) { + /* + * At this point, core protection will be disabled if + * - if the provider is not protected at all + * - if the calling consumer is the only one which has exclusivity + * over the provider + */ + if (clk_core_rate_is_protected(core)) { + req->rate = core->rate; + } else if (core->ops->determine_rate) { return core->ops->determine_rate(core->hw, req); } else if (core->ops->round_rate) { rate = core->ops->round_rate(core->hw, req->rate, @@ -935,12 +1087,55 @@ static int clk_core_round_rate_nolock(struct clk_core *core, return rate; req->rate = rate; - } else if (core->flags & CLK_SET_RATE_PARENT) { - return clk_core_round_rate_nolock(parent, req); } else { - req->rate = core->rate; + return -EINVAL; + } + + return 0; +} + +static void clk_core_init_rate_req(struct clk_core * const core, + struct clk_rate_request *req) +{ + struct clk_core *parent; + + if (WARN_ON(!core || !req)) + return; + + parent = core->parent; + if (parent) { + req->best_parent_hw = parent->hw; + req->best_parent_rate = parent->rate; + } else { + req->best_parent_hw = NULL; + req->best_parent_rate = 0; } +} +static bool clk_core_can_round(struct clk_core * const core) +{ + if (core->ops->determine_rate || core->ops->round_rate) + return true; + + return false; +} + +static int clk_core_round_rate_nolock(struct clk_core *core, + struct clk_rate_request *req) +{ + lockdep_assert_held(&prepare_lock); + + if (!core) + return 0; + + clk_core_init_rate_req(core, req); + + if (clk_core_can_round(core)) + return clk_core_determine_round_nolock(core, req); + else if (core->flags & CLK_SET_RATE_PARENT) + return clk_core_round_rate_nolock(core->parent, req); + + req->rate = core->rate; return 0; } @@ -997,10 +1192,17 @@ long clk_round_rate(struct clk *clk, unsigned long rate) clk_prepare_lock(); + if (clk->exclusive_count) + clk_core_rate_unprotect(clk->core); + clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate); req.rate = rate; ret = clk_core_round_rate_nolock(clk->core, &req); + + if (clk->exclusive_count) + clk_core_rate_protect(clk->core); + clk_prepare_unlock(); if (ret) @@ -1433,34 +1635,23 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *core, clk_core_get_boundaries(core, &min_rate, &max_rate); /* find the closest rate and parent clk/rate */ - if (core->ops->determine_rate) { + if (clk_core_can_round(core)) { struct clk_rate_request req; req.rate = rate; req.min_rate = min_rate; req.max_rate = max_rate; - if (parent) { - req.best_parent_hw = parent->hw; - req.best_parent_rate = parent->rate; - } else { - req.best_parent_hw = NULL; - req.best_parent_rate = 0; - } - ret = core->ops->determine_rate(core->hw, &req); + clk_core_init_rate_req(core, &req); + + ret = clk_core_determine_round_nolock(core, &req); if (ret < 0) return NULL; best_parent_rate = req.best_parent_rate; new_rate = req.rate; parent = req.best_parent_hw ? req.best_parent_hw->core : NULL; - } else if (core->ops->round_rate) { - ret = core->ops->round_rate(core->hw, rate, - &best_parent_rate); - if (ret < 0) - return NULL; - new_rate = ret; if (new_rate < min_rate || new_rate > max_rate) return NULL; } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) { @@ -1642,25 +1833,58 @@ static void clk_change_rate(struct clk_core *core) clk_pm_runtime_put(core); } +static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core, + unsigned long req_rate) +{ + int ret, cnt; + struct clk_rate_request req; + + lockdep_assert_held(&prepare_lock); + + if (!core) + return 0; + + /* simulate what the rate would be if it could be freely set */ + cnt = clk_core_rate_nuke_protect(core); + if (cnt < 0) + return cnt; + + clk_core_get_boundaries(core, &req.min_rate, &req.max_rate); + req.rate = req_rate; + + ret = clk_core_round_rate_nolock(core, &req); + + /* restore the protection */ + clk_core_rate_restore_protect(core, cnt); + + return ret ? 0 : req.rate; +} + static int clk_core_set_rate_nolock(struct clk_core *core, unsigned long req_rate) { struct clk_core *top, *fail_clk; - unsigned long rate = req_rate; + unsigned long rate; int ret = 0; if (!core) return 0; + rate = clk_core_req_round_rate_nolock(core, req_rate); + /* bail early if nothing to do */ if (rate == clk_core_get_rate_nolock(core)) return 0; + /* fail on a direct rate set of a protected provider */ + if (clk_core_rate_is_protected(core)) + return -EBUSY; + if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count) return -EBUSY; /* calculate new rates and get the topmost changed clock */ - top = clk_calc_new_rates(core, rate); + top = clk_calc_new_rates(core, req_rate); if (!top) return -EINVAL; @@ -1719,8 +1943,14 @@ int clk_set_rate(struct clk *clk, unsigned long rate) /* prevent racing with updates to the clock topology */ clk_prepare_lock(); + if (clk->exclusive_count) + clk_core_rate_unprotect(clk->core); + ret = clk_core_set_rate_nolock(clk->core, rate); + if (clk->exclusive_count) + clk_core_rate_protect(clk->core); + clk_prepare_unlock(); return ret; @@ -1728,6 +1958,53 @@ int clk_set_rate(struct clk *clk, unsigned long rate) EXPORT_SYMBOL_GPL(clk_set_rate); /** + * clk_set_rate_exclusive - specify a new rate get exclusive control + * @clk: the clk whose rate is being changed + * @rate: the new rate for clk + * + * This is a combination of clk_set_rate() and clk_rate_exclusive_get() + * within a critical section + * + * This can be used initially to ensure that at least 1 consumer is + * statisfied when several consumers are competing for exclusivity over the + * same clock provider. + * + * The exclusivity is not applied if setting the rate failed. + * + * Calls to clk_rate_exclusive_get() should be balanced with calls to + * clk_rate_exclusive_put(). + * + * Returns 0 on success, -EERROR otherwise. + */ +int clk_set_rate_exclusive(struct clk *clk, unsigned long rate) +{ + int ret; + + if (!clk) + return 0; + + /* prevent racing with updates to the clock topology */ + clk_prepare_lock(); + + /* + * The temporary protection removal is not here, on purpose + * This function is meant to be used instead of clk_rate_protect, + * so before the consumer code path protect the clock provider + */ + + ret = clk_core_set_rate_nolock(clk->core, rate); + if (!ret) { + clk_core_rate_protect(clk->core); + clk->exclusive_count++; + } + + clk_prepare_unlock(); + + return ret; +} +EXPORT_SYMBOL_GPL(clk_set_rate_exclusive); + +/** * clk_set_rate_range - set a rate range for a clock source * @clk: clock source * @min: desired minimum clock rate in Hz, inclusive @@ -1738,6 +2015,7 @@ EXPORT_SYMBOL_GPL(clk_set_rate); int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max) { int ret = 0; + unsigned long old_min, old_max, rate; if (!clk) return 0; @@ -1751,12 +2029,46 @@ int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max) clk_prepare_lock(); - if (min != clk->min_rate || max != clk->max_rate) { - clk->min_rate = min; - clk->max_rate = max; - ret = clk_core_set_rate_nolock(clk->core, clk->core->req_rate); + if (clk->exclusive_count) + clk_core_rate_unprotect(clk->core); + + /* Save the current values in case we need to rollback the change */ + old_min = clk->min_rate; + old_max = clk->max_rate; + clk->min_rate = min; + clk->max_rate = max; + + rate = clk_core_get_rate_nolock(clk->core); + if (rate < min || rate > max) { + /* + * FIXME: + * We are in bit of trouble here, current rate is outside the + * the requested range. We are going try to request appropriate + * range boundary but there is a catch. It may fail for the + * usual reason (clock broken, clock protected, etc) but also + * because: + * - round_rate() was not favorable and fell on the wrong + * side of the boundary + * - the determine_rate() callback does not really check for + * this corner case when determining the rate + */ + + if (rate < min) + rate = min; + else + rate = max; + + ret = clk_core_set_rate_nolock(clk->core, rate); + if (ret) { + /* rollback the changes */ + clk->min_rate = old_min; + clk->max_rate = old_max; + } } + if (clk->exclusive_count) + clk_core_rate_protect(clk->core); + clk_prepare_unlock(); return ret; @@ -1877,32 +2189,31 @@ bool clk_has_parent(struct clk *clk, struct clk *parent) } EXPORT_SYMBOL_GPL(clk_has_parent); -static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent) +static int clk_core_set_parent_nolock(struct clk_core *core, + struct clk_core *parent) { int ret = 0; int p_index = 0; unsigned long p_rate = 0; + lockdep_assert_held(&prepare_lock); + if (!core) return 0; - /* prevent racing with updates to the clock topology */ - clk_prepare_lock(); - if (core->parent == parent) - goto out; + return 0; /* verify ops for for multi-parent clks */ - if ((core->num_parents > 1) && (!core->ops->set_parent)) { - ret = -ENOSYS; - goto out; - } + if (core->num_parents > 1 && !core->ops->set_parent) + return -EPERM; /* check that we are allowed to re-parent if the clock is in use */ - if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) { - ret = -EBUSY; - goto out; - } + if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) + return -EBUSY; + + if (clk_core_rate_is_protected(core)) + return -EBUSY; /* try finding the new parent index */ if (parent) { @@ -1910,15 +2221,14 @@ static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent) if (p_index < 0) { pr_debug("%s: clk %s can not be parent of clk %s\n", __func__, parent->name, core->name); - ret = p_index; - goto out; + return p_index; } p_rate = parent->rate; } ret = clk_pm_runtime_get(core); if (ret) - goto out; + return ret; /* propagate PRE_RATE_CHANGE notifications */ ret = __clk_speculate_rates(core, p_rate); @@ -1940,8 +2250,6 @@ static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent) runtime_put: clk_pm_runtime_put(core); -out: - clk_prepare_unlock(); return ret; } @@ -1965,13 +2273,50 @@ out: */ int clk_set_parent(struct clk *clk, struct clk *parent) { + int ret; + if (!clk) return 0; - return clk_core_set_parent(clk->core, parent ? parent->core : NULL); + clk_prepare_lock(); + + if (clk->exclusive_count) + clk_core_rate_unprotect(clk->core); + + ret = clk_core_set_parent_nolock(clk->core, + parent ? parent->core : NULL); + + if (clk->exclusive_count) + clk_core_rate_protect(clk->core); + + clk_prepare_unlock(); + + return ret; } EXPORT_SYMBOL_GPL(clk_set_parent); +static int clk_core_set_phase_nolock(struct clk_core *core, int degrees) +{ + int ret = -EINVAL; + + lockdep_assert_held(&prepare_lock); + + if (!core) + return 0; + + if (clk_core_rate_is_protected(core)) + return -EBUSY; + + trace_clk_set_phase(core, degrees); + + if (core->ops->set_phase) + ret = core->ops->set_phase(core->hw, degrees); + + trace_clk_set_phase_complete(core, degrees); + + return ret; +} + /** * clk_set_phase - adjust the phase shift of a clock signal * @clk: clock signal source @@ -1994,7 +2339,7 @@ EXPORT_SYMBOL_GPL(clk_set_parent); */ int clk_set_phase(struct clk *clk, int degrees) { - int ret = -EINVAL; + int ret; if (!clk) return 0; @@ -2006,15 +2351,13 @@ int clk_set_phase(struct clk *clk, int degrees) clk_prepare_lock(); - trace_clk_set_phase(clk->core, degrees); + if (clk->exclusive_count) + clk_core_rate_unprotect(clk->core); - if (clk->core->ops->set_phase) - ret = clk->core->ops->set_phase(clk->core->hw, degrees); + ret = clk_core_set_phase_nolock(clk->core, degrees); - trace_clk_set_phase_complete(clk->core, degrees); - - if (!ret) - clk->core->phase = degrees; + if (clk->exclusive_count) + clk_core_rate_protect(clk->core); clk_prepare_unlock(); @@ -2102,11 +2445,12 @@ static void clk_summary_show_one(struct seq_file *s, struct clk_core *c, if (!c) return; - seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu %-3d\n", + seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu %-3d\n", level * 3 + 1, "", 30 - level * 3, c->name, - c->enable_count, c->prepare_count, clk_core_get_rate(c), - clk_core_get_accuracy(c), clk_core_get_phase(c)); + c->enable_count, c->prepare_count, c->protect_count, + clk_core_get_rate(c), clk_core_get_accuracy(c), + clk_core_get_phase(c)); } static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c, @@ -2128,7 +2472,8 @@ static int clk_summary_show(struct seq_file *s, void *data) struct clk_core *c; struct hlist_head **lists = (struct hlist_head **)s->private; - seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy phase\n"); + seq_puts(s, " enable prepare protect \n"); + seq_puts(s, " clock count count count rate accuracy phase\n"); seq_puts(s, "----------------------------------------------------------------------------------------\n"); clk_prepare_lock(); @@ -2164,6 +2509,7 @@ static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level) seq_printf(s, "\"%s\": { ", c->name); seq_printf(s, "\"enable_count\": %d,", c->enable_count); seq_printf(s, "\"prepare_count\": %d,", c->prepare_count); + seq_printf(s, "\"protect_count\": %d,", c->protect_count); seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c)); seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c)); seq_printf(s, "\"phase\": %d", clk_core_get_phase(c)); @@ -2223,6 +2569,58 @@ static const struct file_operations clk_dump_fops = { .release = single_release, }; +static const struct { + unsigned long flag; + const char *name; +} clk_flags[] = { +#define ENTRY(f) { f, __stringify(f) } + ENTRY(CLK_SET_RATE_GATE), + ENTRY(CLK_SET_PARENT_GATE), + ENTRY(CLK_SET_RATE_PARENT), + ENTRY(CLK_IGNORE_UNUSED), + ENTRY(CLK_IS_BASIC), + ENTRY(CLK_GET_RATE_NOCACHE), + ENTRY(CLK_SET_RATE_NO_REPARENT), + ENTRY(CLK_GET_ACCURACY_NOCACHE), + ENTRY(CLK_RECALC_NEW_RATES), + ENTRY(CLK_SET_RATE_UNGATE), + ENTRY(CLK_IS_CRITICAL), + ENTRY(CLK_OPS_PARENT_ENABLE), +#undef ENTRY +}; + +static int clk_flags_dump(struct seq_file *s, void *data) +{ + struct clk_core *core = s->private; + unsigned long flags = core->flags; + unsigned int i; + + for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) { + if (flags & clk_flags[i].flag) { + seq_printf(s, "%s\n", clk_flags[i].name); + flags &= ~clk_flags[i].flag; + } + } + if (flags) { + /* Unknown flags */ + seq_printf(s, "0x%lx\n", flags); + } + + return 0; +} + +static int clk_flags_open(struct inode *inode, struct file *file) +{ + return single_open(file, clk_flags_dump, inode->i_private); +} + +static const struct file_operations clk_flags_fops = { + .open = clk_flags_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + static int possible_parents_dump(struct seq_file *s, void *data) { struct clk_core *core = s->private; @@ -2264,43 +2662,46 @@ static int clk_debug_create_one(struct clk_core *core, struct dentry *pdentry) core->dentry = d; - d = debugfs_create_u32("clk_rate", S_IRUGO, core->dentry, - (u32 *)&core->rate); + d = debugfs_create_ulong("clk_rate", 0444, core->dentry, &core->rate); if (!d) goto err_out; - d = debugfs_create_u32("clk_accuracy", S_IRUGO, core->dentry, - (u32 *)&core->accuracy); + d = debugfs_create_ulong("clk_accuracy", 0444, core->dentry, + &core->accuracy); if (!d) goto err_out; - d = debugfs_create_u32("clk_phase", S_IRUGO, core->dentry, - (u32 *)&core->phase); + d = debugfs_create_u32("clk_phase", 0444, core->dentry, &core->phase); if (!d) goto err_out; - d = debugfs_create_x32("clk_flags", S_IRUGO, core->dentry, - (u32 *)&core->flags); + d = debugfs_create_file("clk_flags", 0444, core->dentry, core, + &clk_flags_fops); if (!d) goto err_out; - d = debugfs_create_u32("clk_prepare_count", S_IRUGO, core->dentry, - (u32 *)&core->prepare_count); + d = debugfs_create_u32("clk_prepare_count", 0444, core->dentry, + &core->prepare_count); if (!d) goto err_out; - d = debugfs_create_u32("clk_enable_count", S_IRUGO, core->dentry, - (u32 *)&core->enable_count); + d = debugfs_create_u32("clk_enable_count", 0444, core->dentry, + &core->enable_count); if (!d) goto err_out; - d = debugfs_create_u32("clk_notifier_count", S_IRUGO, core->dentry, - (u32 *)&core->notifier_count); + d = debugfs_create_u32("clk_protect_count", 0444, core->dentry, + &core->protect_count); + if (!d) + goto err_out; + + d = debugfs_create_u32("clk_notifier_count", 0444, core->dentry, + &core->notifier_count); if (!d) goto err_out; if (core->num_parents > 1) { - d = debugfs_create_file("clk_possible_parents", S_IRUGO, + d = debugfs_create_file("clk_possible_parents", 0444, core->dentry, core, &possible_parents_fops); if (!d) goto err_out; @@ -2336,12 +2737,8 @@ static int clk_debug_register(struct clk_core *core) mutex_lock(&clk_debug_lock); hlist_add_head(&core->debug_node, &clk_debug_list); - - if (!inited) - goto unlock; - - ret = clk_debug_create_one(core, rootdir); -unlock: + if (inited) + ret = clk_debug_create_one(core, rootdir); mutex_unlock(&clk_debug_lock); return ret; @@ -2396,22 +2793,22 @@ static int __init clk_debug_init(void) if (!rootdir) return -ENOMEM; - d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists, + d = debugfs_create_file("clk_summary", 0444, rootdir, &all_lists, &clk_summary_fops); if (!d) return -ENOMEM; - d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists, + d = debugfs_create_file("clk_dump", 0444, rootdir, &all_lists, &clk_dump_fops); if (!d) return -ENOMEM; - d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir, + d = debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list, &clk_summary_fops); if (!d) return -ENOMEM; - d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir, + d = debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list, &clk_dump_fops); if (!d) return -ENOMEM; @@ -2576,14 +2973,17 @@ static int __clk_core_init(struct clk_core *core) */ hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) { struct clk_core *parent = __clk_init_parent(orphan); + unsigned long flags; /* * we could call __clk_set_parent, but that would result in a * redundant call to the .set_rate op, if it exists */ if (parent) { - __clk_set_parent_before(orphan, parent); - __clk_set_parent_after(orphan, parent, NULL); + /* update the clk tree topology */ + flags = clk_enable_lock(); + clk_reparent(orphan, parent); + clk_enable_unlock(flags); __clk_recalc_accuracies(orphan); __clk_recalc_rates(orphan, 0); } @@ -2684,7 +3084,13 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) ret = -ENOMEM; goto fail_name; } + + if (WARN_ON(!hw->init->ops)) { + ret = -EINVAL; + goto fail_ops; + } core->ops = hw->init->ops; + if (dev && pm_runtime_enabled(dev)) core->dev = dev; if (dev && dev->driver) @@ -2746,6 +3152,7 @@ fail_parent_names_copy: kfree_const(core->parent_names[i]); kfree(core->parent_names); fail_parent_names: +fail_ops: kfree_const(core->name); fail_name: kfree(core); @@ -2857,7 +3264,7 @@ void clk_unregister(struct clk *clk) /* Reparent all children to the orphan list. */ hlist_for_each_entry_safe(child, t, &clk->core->children, child_node) - clk_core_set_parent(child, NULL); + clk_core_set_parent_nolock(child, NULL); } hlist_del_init(&clk->core->child_node); @@ -2865,6 +3272,11 @@ void clk_unregister(struct clk *clk) if (clk->core->prepare_count) pr_warn("%s: unregistering prepared clock: %s\n", __func__, clk->core->name); + + if (clk->core->protect_count) + pr_warn("%s: unregistering protected clock: %s\n", + __func__, clk->core->name); + kref_put(&clk->core->ref, __clk_release); unlock: clk_prepare_unlock(); @@ -3023,6 +3435,18 @@ void __clk_put(struct clk *clk) clk_prepare_lock(); + /* + * Before calling clk_put, all calls to clk_rate_exclusive_get() from a + * given user should be balanced with calls to clk_rate_exclusive_put() + * and by that same consumer + */ + if (WARN_ON(clk->exclusive_count)) { + /* We voiced our concern, let's sanitize the situation */ + clk->core->protect_count -= (clk->exclusive_count - 1); + clk_core_rate_unprotect(clk->core); + clk->exclusive_count = 0; + } + hlist_del(&clk->clks_node); if (clk->min_rate > clk->core->req_rate || clk->max_rate < clk->core->req_rate) @@ -3559,7 +3983,7 @@ static int parent_ready(struct device_node *np) * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree * @np: Device node pointer associated with clock provider * @index: clock index - * @flags: pointer to clk_core->flags + * @flags: pointer to top-level framework flags * * Detects if the clock-critical property exists and, if so, sets the * corresponding CLK_IS_CRITICAL flag. |