root/drivers/staging/media/ipu3/ipu3-css-pool.c

DEFINITIONS

1. imgu_css_dma_buffer_resize
2. imgu_css_pool_cleanup
3. imgu_css_pool_init
4. imgu_css_pool_get
5. imgu_css_pool_put
6. imgu_css_pool_last

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2018 Intel Corporation
   3 
   4 #include <linux/device.h>
   5 
   6 #include "ipu3.h"
   7 #include "ipu3-css-pool.h"
   8 #include "ipu3-dmamap.h"
   9 
  10 int imgu_css_dma_buffer_resize(struct imgu_device *imgu,
  11                                struct imgu_css_map *map, size_t size)
  12 {
  13         if (map->size < size && map->vaddr) {
  14                 dev_warn(&imgu->pci_dev->dev, "dma buf resized from %zu to %zu",
  15                          map->size, size);
  16 
  17                 imgu_dmamap_free(imgu, map);
  18                 if (!imgu_dmamap_alloc(imgu, map, size))
  19                         return -ENOMEM;
  20         }
  21 
  22         return 0;
  23 }
  24 
  25 void imgu_css_pool_cleanup(struct imgu_device *imgu, struct imgu_css_pool *pool)
  26 {
  27         unsigned int i;
  28 
  29         for (i = 0; i < IPU3_CSS_POOL_SIZE; i++)
  30                 imgu_dmamap_free(imgu, &pool->entry[i].param);
  31 }
  32 
  33 int imgu_css_pool_init(struct imgu_device *imgu, struct imgu_css_pool *pool,
  34                        size_t size)
  35 {
  36         unsigned int i;
  37 
  38         for (i = 0; i < IPU3_CSS_POOL_SIZE; i++) {
  39                 pool->entry[i].valid = false;
  40                 if (size == 0) {
  41                         pool->entry[i].param.vaddr = NULL;
  42                         continue;
  43                 }
  44 
  45                 if (!imgu_dmamap_alloc(imgu, &pool->entry[i].param, size))
  46                         goto fail;
  47         }
  48 
  49         pool->last = IPU3_CSS_POOL_SIZE;
  50 
  51         return 0;
  52 
  53 fail:
  54         imgu_css_pool_cleanup(imgu, pool);
  55         return -ENOMEM;
  56 }
  57 
  58 /*
  59  * Allocate a new parameter via recycling the oldest entry in the pool.
  60  */
  61 void imgu_css_pool_get(struct imgu_css_pool *pool)
  62 {
  63         /* Get the oldest entry */
  64         u32 n = (pool->last + 1) % IPU3_CSS_POOL_SIZE;
  65 
  66         pool->entry[n].valid = true;
  67         pool->last = n;
  68 }
  69 
  70 /*
  71  * Undo, for all practical purposes, the effect of pool_get().
  72  */
  73 void imgu_css_pool_put(struct imgu_css_pool *pool)
  74 {
  75         pool->entry[pool->last].valid = false;
  76         pool->last = (pool->last + IPU3_CSS_POOL_SIZE - 1) % IPU3_CSS_POOL_SIZE;
  77 }
  78 
  79 /**
  80  * imgu_css_pool_last - Retrieve the nth pool entry from last
  81  *
  82  * @pool: a pointer to &struct imgu_css_pool.
  83  * @n: the distance to the last index.
  84  *
  85  * Returns:
  86  *  The nth entry from last or null map to indicate no frame stored.
  87  */
  88 const struct imgu_css_map *
  89 imgu_css_pool_last(struct imgu_css_pool *pool, unsigned int n)
  90 {
  91         static const struct imgu_css_map null_map = { 0 };
  92         int i = (pool->last + IPU3_CSS_POOL_SIZE - n) % IPU3_CSS_POOL_SIZE;
  93 
  94         WARN_ON(n >= IPU3_CSS_POOL_SIZE);
  95 
  96         if (!pool->entry[i].valid)
  97                 return &null_map;
  98 
  99         return &pool->entry[i].param;
 100 }