LXR uboot/include/smem.h

   1/* SPDX-License-Identifier: GPL-2.0+ */
   2/*
   3 * The shared memory system is an allocate-only heap structure that
   4 * consists of one of more memory areas that can be accessed by the processors
   5 * in the SoC.
   6 *
   7 * Allocation can be done globally for all processors or to an individual processor.
   8 * This is controlled by the @host parameter.
   9 *
  10 * Allocation and management of heap can be implemented in various ways,
  11 * The @item parameter should be used as an index/hash to the memory region.
  12 *
  13 * Copyright (c) 2018 Ramon Fried <ramon.fried@gmail.com>
  14 */
  15
  16#ifndef _smemh_
  17#define _smemh_
  18
  19/* struct smem_ops: Operations for the SMEM uclass */
  20struct smem_ops {
  21        /**
  22         * alloc() - allocate space for a smem item
  23         *
  24         * @host:       remote processor id, or -1 for all processors.
  25         * @item:       smem item handle
  26         * @size:       number of bytes to be allocated
  27         * @return 0 if OK, -ve on error
  28         */
  29        int (*alloc)(unsigned int host,
  30                unsigned int item, size_t size);
  31
  32        /**
  33         * get() - Resolve ptr of size of a smem item
  34         *
  35         * @host:       the remote processor, of -1 for all processors.
  36         * @item:       smem item handle
  37         * @size:       pointer to be filled out with the size of the item
  38         * @return      pointer on success, NULL on error
  39         */
  40        void *(*get)(unsigned int host,
  41                unsigned int item, size_t *size);
  42
  43        /**
  44         * get_free_space() - Get free space in smem in bytes
  45         *
  46         * @host:   the remote processor identifying a partition, or -1
  47         *                      for all processors.
  48         * @return      free space, -ve on error
  49         */
  50        int (*get_free_space)(unsigned int host);
  51};
  52
  53#define smem_get_ops(dev)       ((struct smem_ops *)(dev)->driver->ops)
  54
  55/**
  56 * smem_alloc() - allocate space for a smem item
  57 * @host:       remote processor id, or -1
  58 * @item:       smem item handle
  59 * @size:       number of bytes to be allocated
  60 * @return 0 if OK, -ve on error
  61 *
  62 * Allocate space for a given smem item of size @size, given that the item is
  63 * not yet allocated.
  64 */
  65int smem_alloc(struct udevice *dev, unsigned int host, unsigned int item, size_t size);
  66
  67/**
  68 * smem_get() - resolve ptr of size of a smem item
  69 * @host:       the remote processor, or -1 for all processors.
  70 * @item:       smem item handle
  71 * @size:       pointer to be filled out with size of the item
  72 * @return      pointer on success, NULL on error
  73 *
  74 * Looks up smem item and returns pointer to it. Size of smem
  75 * item is returned in @size.
  76 */
  77void *smem_get(struct udevice *dev, unsigned int host, unsigned int item, size_t *size);
  78
  79/**
  80 * smem_get_free_space() - retrieve amount of free space in a partition
  81 * @host:       the remote processor identifying a partition, or -1
  82 *                      for all processors.
  83 * @return      size in bytes, -ve on error
  84 *
  85 * To be used by smem clients as a quick way to determine if any new
  86 * allocations has been made.
  87 */
  88int smem_get_free_space(struct udevice *dev, unsigned int host);
  89
  90#endif /* _smem_h_ */
  91
  92