LCOV - code coverage report
Current view: top level - sound/core - pcm_memory.c (source / functions) Hit Total Coverage
Test: Real Lines: 26 122 21.3 %
Date: 2020-10-17 15:46:16 Functions: 0 15 0.0 %
Legend: Neither, QEMU, Real, Both Branches: 0 0 -

           Branch data     Line data    Source code
       1                 :            : // SPDX-License-Identifier: GPL-2.0-or-later
       2                 :            : /*
       3                 :            :  *  Digital Audio (PCM) abstract layer
       4                 :            :  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
       5                 :            :  */
       6                 :            : 
       7                 :            : #include <linux/io.h>
       8                 :            : #include <linux/time.h>
       9                 :            : #include <linux/init.h>
      10                 :            : #include <linux/slab.h>
      11                 :            : #include <linux/moduleparam.h>
      12                 :            : #include <linux/vmalloc.h>
      13                 :            : #include <linux/export.h>
      14                 :            : #include <sound/core.h>
      15                 :            : #include <sound/pcm.h>
      16                 :            : #include <sound/info.h>
      17                 :            : #include <sound/initval.h>
      18                 :            : 
      19                 :            : static int preallocate_dma = 1;
      20                 :            : module_param(preallocate_dma, int, 0444);
      21                 :            : MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
      22                 :            : 
      23                 :            : static int maximum_substreams = 4;
      24                 :            : module_param(maximum_substreams, int, 0444);
      25                 :            : MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
      26                 :            : 
      27                 :            : static const size_t snd_minimum_buffer = 16384;
      28                 :            : 
      29                 :            : 
      30                 :            : /*
      31                 :            :  * try to allocate as the large pages as possible.
      32                 :            :  * stores the resultant memory size in *res_size.
      33                 :            :  *
      34                 :            :  * the minimum size is snd_minimum_buffer.  it should be power of 2.
      35                 :            :  */
      36                 :          3 : static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size)
      37                 :            : {
      38                 :          3 :         struct snd_dma_buffer *dmab = &substream->dma_buffer;
      39                 :            :         size_t orig_size = size;
      40                 :            :         int err;
      41                 :            : 
      42                 :            :         do {
      43                 :          3 :                 if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev,
      44                 :            :                                                size, dmab)) < 0) {
      45                 :          0 :                         if (err != -ENOMEM)
      46                 :          0 :                                 return err; /* fatal error */
      47                 :            :                 } else
      48                 :            :                         return 0;
      49                 :          0 :                 size >>= 1;
      50                 :          0 :         } while (size >= snd_minimum_buffer);
      51                 :          0 :         dmab->bytes = 0; /* tell error */
      52                 :          0 :         pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
      53                 :            :                 substream->pcm->card->number, substream->pcm->device,
      54                 :            :                 substream->stream ? 'c' : 'p', substream->number,
      55                 :            :                 substream->pcm->name, orig_size);
      56                 :          0 :         return 0;
      57                 :            : }
      58                 :            : 
      59                 :            : /*
      60                 :            :  * release the preallocated buffer if not yet done.
      61                 :            :  */
      62                 :            : static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
      63                 :            : {
      64                 :          0 :         if (substream->dma_buffer.area == NULL)
      65                 :            :                 return;
      66                 :          0 :         snd_dma_free_pages(&substream->dma_buffer);
      67                 :          0 :         substream->dma_buffer.area = NULL;
      68                 :            : }
      69                 :            : 
      70                 :            : /**
      71                 :            :  * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
      72                 :            :  * @substream: the pcm substream instance
      73                 :            :  *
      74                 :            :  * Releases the pre-allocated buffer of the given substream.
      75                 :            :  */
      76                 :          0 : void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
      77                 :            : {
      78                 :            :         snd_pcm_lib_preallocate_dma_free(substream);
      79                 :          0 : }
      80                 :            : 
      81                 :            : /**
      82                 :            :  * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
      83                 :            :  * @pcm: the pcm instance
      84                 :            :  *
      85                 :            :  * Releases all the pre-allocated buffers on the given pcm.
      86                 :            :  */
      87                 :          0 : void snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
      88                 :            : {
      89                 :            :         struct snd_pcm_substream *substream;
      90                 :            :         int stream;
      91                 :            : 
      92                 :          0 :         for (stream = 0; stream < 2; stream++)
      93                 :          0 :                 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
      94                 :            :                         snd_pcm_lib_preallocate_free(substream);
      95                 :          0 : }
      96                 :            : EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
      97                 :            : 
      98                 :            : #ifdef CONFIG_SND_VERBOSE_PROCFS
      99                 :            : /*
     100                 :            :  * read callback for prealloc proc file
     101                 :            :  *
     102                 :            :  * prints the current allocated size in kB.
     103                 :            :  */
     104                 :          0 : static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
     105                 :            :                                               struct snd_info_buffer *buffer)
     106                 :            : {
     107                 :          0 :         struct snd_pcm_substream *substream = entry->private_data;
     108                 :          0 :         snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
     109                 :          0 : }
     110                 :            : 
     111                 :            : /*
     112                 :            :  * read callback for prealloc_max proc file
     113                 :            :  *
     114                 :            :  * prints the maximum allowed size in kB.
     115                 :            :  */
     116                 :          0 : static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
     117                 :            :                                                   struct snd_info_buffer *buffer)
     118                 :            : {
     119                 :          0 :         struct snd_pcm_substream *substream = entry->private_data;
     120                 :          0 :         snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
     121                 :          0 : }
     122                 :            : 
     123                 :            : /*
     124                 :            :  * write callback for prealloc proc file
     125                 :            :  *
     126                 :            :  * accepts the preallocation size in kB.
     127                 :            :  */
     128                 :          0 : static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
     129                 :            :                                                struct snd_info_buffer *buffer)
     130                 :            : {
     131                 :          0 :         struct snd_pcm_substream *substream = entry->private_data;
     132                 :            :         char line[64], str[64];
     133                 :            :         size_t size;
     134                 :            :         struct snd_dma_buffer new_dmab;
     135                 :            : 
     136                 :          0 :         if (substream->runtime) {
     137                 :          0 :                 buffer->error = -EBUSY;
     138                 :          0 :                 return;
     139                 :            :         }
     140                 :          0 :         if (!snd_info_get_line(buffer, line, sizeof(line))) {
     141                 :          0 :                 snd_info_get_str(str, line, sizeof(str));
     142                 :          0 :                 size = simple_strtoul(str, NULL, 10) * 1024;
     143                 :          0 :                 if ((size != 0 && size < 8192) || size > substream->dma_max) {
     144                 :          0 :                         buffer->error = -EINVAL;
     145                 :          0 :                         return;
     146                 :            :                 }
     147                 :          0 :                 if (substream->dma_buffer.bytes == size)
     148                 :            :                         return;
     149                 :          0 :                 memset(&new_dmab, 0, sizeof(new_dmab));
     150                 :          0 :                 new_dmab.dev = substream->dma_buffer.dev;
     151                 :          0 :                 if (size > 0) {
     152                 :          0 :                         if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
     153                 :            :                                                 substream->dma_buffer.dev.dev,
     154                 :            :                                                 size, &new_dmab) < 0) {
     155                 :          0 :                                 buffer->error = -ENOMEM;
     156                 :          0 :                                 return;
     157                 :            :                         }
     158                 :          0 :                         substream->buffer_bytes_max = size;
     159                 :            :                 } else {
     160                 :          0 :                         substream->buffer_bytes_max = UINT_MAX;
     161                 :            :                 }
     162                 :          0 :                 if (substream->dma_buffer.area)
     163                 :          0 :                         snd_dma_free_pages(&substream->dma_buffer);
     164                 :          0 :                 substream->dma_buffer = new_dmab;
     165                 :            :         } else {
     166                 :          0 :                 buffer->error = -EINVAL;
     167                 :            :         }
     168                 :            : }
     169                 :            : 
     170                 :          3 : static inline void preallocate_info_init(struct snd_pcm_substream *substream)
     171                 :            : {
     172                 :            :         struct snd_info_entry *entry;
     173                 :            : 
     174                 :          3 :         entry = snd_info_create_card_entry(substream->pcm->card, "prealloc",
     175                 :            :                                            substream->proc_root);
     176                 :          3 :         if (entry) {
     177                 :            :                 snd_info_set_text_ops(entry, substream,
     178                 :            :                                       snd_pcm_lib_preallocate_proc_read);
     179                 :          3 :                 entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
     180                 :          3 :                 entry->mode |= 0200;
     181                 :            :         }
     182                 :          3 :         entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max",
     183                 :            :                                            substream->proc_root);
     184                 :          3 :         if (entry)
     185                 :            :                 snd_info_set_text_ops(entry, substream,
     186                 :            :                                       snd_pcm_lib_preallocate_max_proc_read);
     187                 :          3 : }
     188                 :            : 
     189                 :            : #else /* !CONFIG_SND_VERBOSE_PROCFS */
     190                 :            : #define preallocate_info_init(s)
     191                 :            : #endif /* CONFIG_SND_VERBOSE_PROCFS */
     192                 :            : 
     193                 :            : /*
     194                 :            :  * pre-allocate the buffer and create a proc file for the substream
     195                 :            :  */
     196                 :          3 : static void snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
     197                 :            :                                           size_t size, size_t max)
     198                 :            : {
     199                 :            : 
     200                 :          3 :         if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
     201                 :          3 :                 preallocate_pcm_pages(substream, size);
     202                 :            : 
     203                 :          3 :         if (substream->dma_buffer.bytes > 0)
     204                 :          3 :                 substream->buffer_bytes_max = substream->dma_buffer.bytes;
     205                 :          3 :         substream->dma_max = max;
     206                 :          3 :         preallocate_info_init(substream);
     207                 :          3 : }
     208                 :            : 
     209                 :            : 
     210                 :            : /**
     211                 :            :  * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
     212                 :            :  * @substream: the pcm substream instance
     213                 :            :  * @type: DMA type (SNDRV_DMA_TYPE_*)
     214                 :            :  * @data: DMA type dependent data
     215                 :            :  * @size: the requested pre-allocation size in bytes
     216                 :            :  * @max: the max. allowed pre-allocation size
     217                 :            :  *
     218                 :            :  * Do pre-allocation for the given DMA buffer type.
     219                 :            :  */
     220                 :          0 : void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
     221                 :            :                                   int type, struct device *data,
     222                 :            :                                   size_t size, size_t max)
     223                 :            : {
     224                 :          3 :         substream->dma_buffer.dev.type = type;
     225                 :          3 :         substream->dma_buffer.dev.dev = data;
     226                 :          3 :         snd_pcm_lib_preallocate_pages1(substream, size, max);
     227                 :          0 : }
     228                 :            : EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
     229                 :            : 
     230                 :            : /**
     231                 :            :  * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
     232                 :            :  * @pcm: the pcm instance
     233                 :            :  * @type: DMA type (SNDRV_DMA_TYPE_*)
     234                 :            :  * @data: DMA type dependent data
     235                 :            :  * @size: the requested pre-allocation size in bytes
     236                 :            :  * @max: the max. allowed pre-allocation size
     237                 :            :  *
     238                 :            :  * Do pre-allocation to all substreams of the given pcm for the
     239                 :            :  * specified DMA type.
     240                 :            :  */
     241                 :          3 : void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
     242                 :            :                                           int type, void *data,
     243                 :            :                                           size_t size, size_t max)
     244                 :            : {
     245                 :            :         struct snd_pcm_substream *substream;
     246                 :            :         int stream;
     247                 :            : 
     248                 :          3 :         for (stream = 0; stream < 2; stream++)
     249                 :          3 :                 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
     250                 :            :                         snd_pcm_lib_preallocate_pages(substream, type, data, size, max);
     251                 :          3 : }
     252                 :            : EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
     253                 :            : 
     254                 :            : #ifdef CONFIG_SND_DMA_SGBUF
     255                 :            : /**
     256                 :            :  * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
     257                 :            :  * @substream: the pcm substream instance
     258                 :            :  * @offset: the buffer offset
     259                 :            :  *
     260                 :            :  * Used as the page callback of PCM ops.
     261                 :            :  *
     262                 :            :  * Return: The page struct at the given buffer offset. %NULL on failure.
     263                 :            :  */
     264                 :            : struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
     265                 :            : {
     266                 :            :         struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
     267                 :            : 
     268                 :            :         unsigned int idx = offset >> PAGE_SHIFT;
     269                 :            :         if (idx >= (unsigned int)sgbuf->pages)
     270                 :            :                 return NULL;
     271                 :            :         return sgbuf->page_table[idx];
     272                 :            : }
     273                 :            : EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
     274                 :            : #endif /* CONFIG_SND_DMA_SGBUF */
     275                 :            : 
     276                 :            : /**
     277                 :            :  * snd_pcm_lib_malloc_pages - allocate the DMA buffer
     278                 :            :  * @substream: the substream to allocate the DMA buffer to
     279                 :            :  * @size: the requested buffer size in bytes
     280                 :            :  *
     281                 :            :  * Allocates the DMA buffer on the BUS type given earlier to
     282                 :            :  * snd_pcm_lib_preallocate_xxx_pages().
     283                 :            :  *
     284                 :            :  * Return: 1 if the buffer is changed, 0 if not changed, or a negative
     285                 :            :  * code on failure.
     286                 :            :  */
     287                 :          0 : int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
     288                 :            : {
     289                 :            :         struct snd_pcm_runtime *runtime;
     290                 :            :         struct snd_dma_buffer *dmab = NULL;
     291                 :            : 
     292                 :          0 :         if (PCM_RUNTIME_CHECK(substream))
     293                 :            :                 return -EINVAL;
     294                 :          0 :         if (snd_BUG_ON(substream->dma_buffer.dev.type ==
     295                 :            :                        SNDRV_DMA_TYPE_UNKNOWN))
     296                 :            :                 return -EINVAL;
     297                 :          0 :         runtime = substream->runtime;
     298                 :            : 
     299                 :          0 :         if (runtime->dma_buffer_p) {
     300                 :            :                 /* perphaps, we might free the large DMA memory region
     301                 :            :                    to save some space here, but the actual solution
     302                 :            :                    costs us less time */
     303                 :          0 :                 if (runtime->dma_buffer_p->bytes >= size) {
     304                 :          0 :                         runtime->dma_bytes = size;
     305                 :          0 :                         return 0;       /* ok, do not change */
     306                 :            :                 }
     307                 :          0 :                 snd_pcm_lib_free_pages(substream);
     308                 :            :         }
     309                 :          0 :         if (substream->dma_buffer.area != NULL &&
     310                 :          0 :             substream->dma_buffer.bytes >= size) {
     311                 :          0 :                 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
     312                 :            :         } else {
     313                 :          0 :                 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
     314                 :          0 :                 if (! dmab)
     315                 :            :                         return -ENOMEM;
     316                 :          0 :                 dmab->dev = substream->dma_buffer.dev;
     317                 :          0 :                 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
     318                 :            :                                         substream->dma_buffer.dev.dev,
     319                 :            :                                         size, dmab) < 0) {
     320                 :          0 :                         kfree(dmab);
     321                 :          0 :                         return -ENOMEM;
     322                 :            :                 }
     323                 :            :         }
     324                 :            :         snd_pcm_set_runtime_buffer(substream, dmab);
     325                 :          0 :         runtime->dma_bytes = size;
     326                 :          0 :         return 1;                       /* area was changed */
     327                 :            : }
     328                 :            : EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
     329                 :            : 
     330                 :            : /**
     331                 :            :  * snd_pcm_lib_free_pages - release the allocated DMA buffer.
     332                 :            :  * @substream: the substream to release the DMA buffer
     333                 :            :  *
     334                 :            :  * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
     335                 :            :  *
     336                 :            :  * Return: Zero if successful, or a negative error code on failure.
     337                 :            :  */
     338                 :          0 : int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
     339                 :            : {
     340                 :            :         struct snd_pcm_runtime *runtime;
     341                 :            : 
     342                 :          0 :         if (PCM_RUNTIME_CHECK(substream))
     343                 :            :                 return -EINVAL;
     344                 :          0 :         runtime = substream->runtime;
     345                 :          0 :         if (runtime->dma_area == NULL)
     346                 :            :                 return 0;
     347                 :          0 :         if (runtime->dma_buffer_p != &substream->dma_buffer) {
     348                 :            :                 /* it's a newly allocated buffer.  release it now. */
     349                 :          0 :                 snd_dma_free_pages(runtime->dma_buffer_p);
     350                 :          0 :                 kfree(runtime->dma_buffer_p);
     351                 :            :         }
     352                 :            :         snd_pcm_set_runtime_buffer(substream, NULL);
     353                 :          0 :         return 0;
     354                 :            : }
     355                 :            : EXPORT_SYMBOL(snd_pcm_lib_free_pages);
     356                 :            : 
     357                 :          0 : int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
     358                 :            :                                       size_t size, gfp_t gfp_flags)
     359                 :            : {
     360                 :            :         struct snd_pcm_runtime *runtime;
     361                 :            : 
     362                 :          0 :         if (PCM_RUNTIME_CHECK(substream))
     363                 :            :                 return -EINVAL;
     364                 :          0 :         runtime = substream->runtime;
     365                 :          0 :         if (runtime->dma_area) {
     366                 :          0 :                 if (runtime->dma_bytes >= size)
     367                 :            :                         return 0; /* already large enough */
     368                 :          0 :                 vfree(runtime->dma_area);
     369                 :            :         }
     370                 :          0 :         runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
     371                 :          0 :         if (!runtime->dma_area)
     372                 :            :                 return -ENOMEM;
     373                 :          0 :         runtime->dma_bytes = size;
     374                 :          0 :         return 1;
     375                 :            : }
     376                 :            : EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
     377                 :            : 
     378                 :            : /**
     379                 :            :  * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
     380                 :            :  * @substream: the substream with a buffer allocated by
     381                 :            :  *      snd_pcm_lib_alloc_vmalloc_buffer()
     382                 :            :  *
     383                 :            :  * Return: Zero if successful, or a negative error code on failure.
     384                 :            :  */
     385                 :          0 : int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
     386                 :            : {
     387                 :            :         struct snd_pcm_runtime *runtime;
     388                 :            : 
     389                 :          0 :         if (PCM_RUNTIME_CHECK(substream))
     390                 :            :                 return -EINVAL;
     391                 :          0 :         runtime = substream->runtime;
     392                 :          0 :         vfree(runtime->dma_area);
     393                 :          0 :         runtime->dma_area = NULL;
     394                 :          0 :         return 0;
     395                 :            : }
     396                 :            : EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
     397                 :            : 
     398                 :            : /**
     399                 :            :  * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
     400                 :            :  * @substream: the substream with a buffer allocated by
     401                 :            :  *      snd_pcm_lib_alloc_vmalloc_buffer()
     402                 :            :  * @offset: offset in the buffer
     403                 :            :  *
     404                 :            :  * This function is to be used as the page callback in the PCM ops.
     405                 :            :  *
     406                 :            :  * Return: The page struct, or %NULL on failure.
     407                 :            :  */
     408                 :          0 : struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
     409                 :            :                                           unsigned long offset)
     410                 :            : {
     411                 :          0 :         return vmalloc_to_page(substream->runtime->dma_area + offset);
     412                 :            : }
     413                 :            : EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);
    

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