cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ipu3-css-pool.c (2250B)

      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
     10int 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
     25void 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
     33int 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
     53fail:
     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 */
     61void 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 */
     73void 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 */
     88const struct imgu_css_map *
     89imgu_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}