summaryrefslogtreecommitdiff
path: root/include/sound
diff options
context:
space:
mode:
authorTakashi Iwai <tiwai@suse.de>2021-08-02 10:28:03 +0300
committerTakashi Iwai <tiwai@suse.de>2021-08-04 09:08:06 +0300
commitac9245a5406e6074a1aa211f103629d3f154c5a5 (patch)
tree068428c901ef2bfeebe94ee8613011e71579f6b7 /include/sound
parent58a95dfa4fdd9c72e62be34dd025d268c1e04a83 (diff)
downloadlinux-ac9245a5406e6074a1aa211f103629d3f154c5a5.tar.xz
ALSA: pcm: Allow exact buffer preallocation
A few drivers want to have rather the exact buffer preallocation at the driver probe time and keep using it for the whole operations without allowing dynamic buffer allocation. For satisfying the demands, this patch extends the managed buffer allocation API slightly. Namely, when 0 is passed to max argument of the allocation helper functions snd_pcm_set_managed_buffer*(), it treats as if the fixed size allocation of the given size. If the pre-allocation fails in this mode, the function returns now -ENOMEM. Otherwise, i.e. max argument is non-zero, the function never returns -ENOMEM but tries to fall back to the smaller chunks and allows the dynamic allocation later -- which is still the default behavior until now. For more intuitive use, also two new helpers are added for handling the fixed size buffer allocation, too: snd_pcm_set_fixed_buffer() and snd_pcm_set_fixed_buffer_all(). Acked-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210802072815.13551-4-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'include/sound')
-rw-r--r--include/sound/pcm.h47
1 files changed, 42 insertions, 5 deletions
diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index 938f36050a5e..33451f8ff755 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -1204,11 +1204,48 @@ void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size);
int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream);
-void snd_pcm_set_managed_buffer(struct snd_pcm_substream *substream, int type,
- struct device *data, size_t size, size_t max);
-void snd_pcm_set_managed_buffer_all(struct snd_pcm *pcm, int type,
- struct device *data,
- size_t size, size_t max);
+int snd_pcm_set_managed_buffer(struct snd_pcm_substream *substream, int type,
+ struct device *data, size_t size, size_t max);
+int snd_pcm_set_managed_buffer_all(struct snd_pcm *pcm, int type,
+ struct device *data,
+ size_t size, size_t max);
+
+/**
+ * snd_pcm_set_fixed_buffer - Preallocate and set up the fixed size PCM buffer
+ * @substream: the pcm substream instance
+ * @type: DMA type (SNDRV_DMA_TYPE_*)
+ * @data: DMA type dependent data
+ * @size: the requested pre-allocation size in bytes
+ *
+ * This is a variant of snd_pcm_set_managed_buffer(), but this pre-allocates
+ * only the given sized buffer and doesn't allow re-allocation nor dynamic
+ * allocation of a larger buffer unlike the standard one.
+ * The function may return -ENOMEM error, hence the caller must check it.
+ */
+static inline int __must_check
+snd_pcm_set_fixed_buffer(struct snd_pcm_substream *substream, int type,
+ struct device *data, size_t size)
+{
+ return snd_pcm_set_managed_buffer(substream, type, data, size, 0);
+}
+
+/**
+ * snd_pcm_set_fixed_buffer_all - Preallocate and set up the fixed size PCM buffer
+ * @pcm: the pcm instance
+ * @type: DMA type (SNDRV_DMA_TYPE_*)
+ * @data: DMA type dependent data
+ * @size: the requested pre-allocation size in bytes
+ *
+ * Apply the set up of the fixed buffer via snd_pcm_set_fixed_buffer() for
+ * all substream. If any of allocation fails, it returns -ENOMEM, hence the
+ * caller must check the return value.
+ */
+static inline int __must_check
+snd_pcm_set_fixed_buffer_all(struct snd_pcm *pcm, int type,
+ struct device *data, size_t size)
+{
+ return snd_pcm_set_managed_buffer_all(pcm, type, data, size, 0);
+}
int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
size_t size, gfp_t gfp_flags);