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

   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 ipu3_css_dma_buffer_resize(struct imgu_device *imgu,
  11                                struct ipu3_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                 ipu3_dmamap_free(imgu, map);
  18                 if (!ipu3_dmamap_alloc(imgu, map, size))
  19                         return -ENOMEM;
  20         }
  21
  22         return 0;
  23 }
  24
  25 void ipu3_css_pool_cleanup(struct imgu_device *imgu, struct ipu3_css_pool *pool)
  26 {
  27         unsigned int i;
  28
  29         for (i = 0; i < IPU3_CSS_POOL_SIZE; i++)
  30                 ipu3_dmamap_free(imgu, &pool->entry[i].param);
  31 }
  32
  33 int ipu3_css_pool_init(struct imgu_device *imgu, struct ipu3_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 (!ipu3_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         ipu3_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 ipu3_css_pool_get(struct ipu3_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 ipu3_css_pool_put(struct ipu3_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  * ipu3_css_pool_last - Retrieve the nth pool entry from last
  81  *
  82  * @pool: a pointer to &struct ipu3_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 ipu3_css_map *
  89 ipu3_css_pool_last(struct ipu3_css_pool *pool, unsigned int n)
  90 {
  91         static const struct ipu3_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 }