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author | 2011-01-10 17:11:39 -0800 | |
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committer | 2011-01-10 17:11:39 -0800 | |
commit | 5b2eef966cb2ae307aa4ef1767f7307774bc96ca (patch) | |
tree | 095a251e145903598dd8d90d5b2eb880f0d6ff93 /lib | |
parent | Merge branch 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git... (diff) | |
parent | drm/radeon/kms: disable underscan by default (diff) | |
download | linux-5b2eef966cb2ae307aa4ef1767f7307774bc96ca.tar.gz linux-5b2eef966cb2ae307aa4ef1767f7307774bc96ca.tar.bz2 linux-5b2eef966cb2ae307aa4ef1767f7307774bc96ca.zip |
Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6
* 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (390 commits)
drm/radeon/kms: disable underscan by default
drm/radeon/kms: only enable hdmi features if the monitor supports audio
drm: Restore the old_fb upon modeset failure
drm/nouveau: fix hwmon device binding
radeon: consolidate asic-specific function decls for pre-r600
vga_switcheroo: comparing too few characters in strncmp()
drm/radeon/kms: add NI pci ids
drm/radeon/kms: don't enable pcie gen2 on NI yet
drm/radeon/kms: add radeon_asic struct for NI asics
drm/radeon/kms/ni: load default sclk/mclk/vddc at pm init
drm/radeon/kms: add ucode loader for NI
drm/radeon/kms: add support for DCE5 display LUTs
drm/radeon/kms: add ni_reg.h
drm/radeon/kms: add bo blit support for NI
drm/radeon/kms: always use writeback/events for fences on NI
drm/radeon/kms: adjust default clock/vddc tracking for pm on DCE5
drm/radeon/kms: add backend map workaround for barts
drm/radeon/kms: fill gpu init for NI asics
drm/radeon/kms: add disabled vbios accessor for NI asics
drm/radeon/kms: handle NI thermal controller
...
Diffstat (limited to 'lib')
-rw-r--r-- | lib/kref.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/lib/kref.c b/lib/kref.c index d3d227a08a4b..3efb882b11db 100644 --- a/lib/kref.c +++ b/lib/kref.c @@ -62,6 +62,36 @@ int kref_put(struct kref *kref, void (*release)(struct kref *kref)) return 0; } + +/** + * kref_sub - subtract a number of refcounts for object. + * @kref: object. + * @count: Number of recounts to subtract. + * @release: pointer to the function that will clean up the object when the + * last reference to the object is released. + * This pointer is required, and it is not acceptable to pass kfree + * in as this function. + * + * Subtract @count from the refcount, and if 0, call release(). + * Return 1 if the object was removed, otherwise return 0. Beware, if this + * function returns 0, you still can not count on the kref from remaining in + * memory. Only use the return value if you want to see if the kref is now + * gone, not present. + */ +int kref_sub(struct kref *kref, unsigned int count, + void (*release)(struct kref *kref)) +{ + WARN_ON(release == NULL); + WARN_ON(release == (void (*)(struct kref *))kfree); + + if (atomic_sub_and_test((int) count, &kref->refcount)) { + release(kref); + return 1; + } + return 0; +} + EXPORT_SYMBOL(kref_init); EXPORT_SYMBOL(kref_get); EXPORT_SYMBOL(kref_put); +EXPORT_SYMBOL(kref_sub); |