diff options
author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2015-07-15 16:36:50 +0200 |
---|---|---|
committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2015-07-15 16:36:50 +0200 |
commit | ca6e4405779ed56ebac941570615abd667c72c02 (patch) | |
tree | 1b4fef494bc8d64ed889d52c7aabb4e09e4ffef3 /drivers/char/random.c | |
parent | 8f539a83efa7dceb7c2257ca96e2dfc846bd12f6 (diff) | |
parent | ccfb8b2ed4d4e12c3c35de3db5fbbbaa11277736 (diff) |
Merge tag 'drm-intel-fixes-2015-07-15' into drm-intel-next-queued
Backmerge fixes since it's getting out of hand again with the massive
split due to atomic between -next and 4.2-rc. All the bugfixes in
4.2-rc are addressed already (by converting more towards atomic
instead of minimal duct-tape) so just always pick the version in next
for the conflicts in modeset code.
All the other conflicts are just adjacent lines changed.
Conflicts:
drivers/gpu/drm/i915/i915_drv.h
drivers/gpu/drm/i915/i915_gem_gtt.c
drivers/gpu/drm/i915/intel_display.c
drivers/gpu/drm/i915/intel_drv.h
drivers/gpu/drm/i915/intel_ringbuffer.h
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Diffstat (limited to 'drivers/char/random.c')
-rw-r--r-- | drivers/char/random.c | 80 |
1 files changed, 79 insertions, 1 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 9cd6968e2f92..d0da5d852d41 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -409,6 +409,9 @@ static DECLARE_WAIT_QUEUE_HEAD(random_write_wait); static DECLARE_WAIT_QUEUE_HEAD(urandom_init_wait); static struct fasync_struct *fasync; +static DEFINE_SPINLOCK(random_ready_list_lock); +static LIST_HEAD(random_ready_list); + /********************************************************************** * * OS independent entropy store. Here are the functions which handle @@ -589,6 +592,22 @@ static void fast_mix(struct fast_pool *f) f->count++; } +static void process_random_ready_list(void) +{ + unsigned long flags; + struct random_ready_callback *rdy, *tmp; + + spin_lock_irqsave(&random_ready_list_lock, flags); + list_for_each_entry_safe(rdy, tmp, &random_ready_list, list) { + struct module *owner = rdy->owner; + + list_del_init(&rdy->list); + rdy->func(rdy); + module_put(owner); + } + spin_unlock_irqrestore(&random_ready_list_lock, flags); +} + /* * Credit (or debit) the entropy store with n bits of entropy. * Use credit_entropy_bits_safe() if the value comes from userspace @@ -660,7 +679,8 @@ retry: r->entropy_total = 0; if (r == &nonblocking_pool) { prandom_reseed_late(); - wake_up_interruptible(&urandom_init_wait); + process_random_ready_list(); + wake_up_all(&urandom_init_wait); pr_notice("random: %s pool is initialized\n", r->name); } } @@ -1245,6 +1265,64 @@ void get_random_bytes(void *buf, int nbytes) EXPORT_SYMBOL(get_random_bytes); /* + * Add a callback function that will be invoked when the nonblocking + * pool is initialised. + * + * returns: 0 if callback is successfully added + * -EALREADY if pool is already initialised (callback not called) + * -ENOENT if module for callback is not alive + */ +int add_random_ready_callback(struct random_ready_callback *rdy) +{ + struct module *owner; + unsigned long flags; + int err = -EALREADY; + + if (likely(nonblocking_pool.initialized)) + return err; + + owner = rdy->owner; + if (!try_module_get(owner)) + return -ENOENT; + + spin_lock_irqsave(&random_ready_list_lock, flags); + if (nonblocking_pool.initialized) + goto out; + + owner = NULL; + + list_add(&rdy->list, &random_ready_list); + err = 0; + +out: + spin_unlock_irqrestore(&random_ready_list_lock, flags); + + module_put(owner); + + return err; +} +EXPORT_SYMBOL(add_random_ready_callback); + +/* + * Delete a previously registered readiness callback function. + */ +void del_random_ready_callback(struct random_ready_callback *rdy) +{ + unsigned long flags; + struct module *owner = NULL; + + spin_lock_irqsave(&random_ready_list_lock, flags); + if (!list_empty(&rdy->list)) { + list_del_init(&rdy->list); + owner = rdy->owner; + } + spin_unlock_irqrestore(&random_ready_list_lock, flags); + + module_put(owner); +} +EXPORT_SYMBOL(del_random_ready_callback); + +/* * This function will use the architecture-specific hardware random * number generator if it is available. The arch-specific hw RNG will * almost certainly be faster than what we can do in software, but it |