drivers/staging/android/ion/ion_chunk_heap.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * drivers/staging/android/ion/ion_chunk_heap.c
   4  *
   5  * Copyright (C) 2012 Google, Inc.
   6  */
   7 #include <linux/dma-mapping.h>
   8 #include <linux/err.h>
   9 #include <linux/genalloc.h>
  10 #include <linux/io.h>
  11 #include <linux/mm.h>
  12 #include <linux/scatterlist.h>
  13 #include <linux/slab.h>
  14 #include <linux/vmalloc.h>
  15 #include "ion.h"
  16
  17 struct ion_chunk_heap {
  18         struct ion_heap heap;
  19         struct gen_pool *pool;
  20         phys_addr_t base;
  21         unsigned long chunk_size;
  22         unsigned long size;
  23         unsigned long allocated;
  24 };
  25
  26 static int ion_chunk_heap_allocate(struct ion_heap *heap,
  27                                    struct ion_buffer *buffer,
  28                                    unsigned long size,
  29                                    unsigned long flags)
  30 {
  31         struct ion_chunk_heap *chunk_heap =
  32                 container_of(heap, struct ion_chunk_heap, heap);
  33         struct sg_table *table;
  34         struct scatterlist *sg;
  35         int ret, i;
  36         unsigned long num_chunks;
  37         unsigned long allocated_size;
  38
  39         allocated_size = ALIGN(size, chunk_heap->chunk_size);
  40         num_chunks = allocated_size / chunk_heap->chunk_size;
  41
  42         if (allocated_size > chunk_heap->size - chunk_heap->allocated)
  43                 return -ENOMEM;
  44
  45         table = kmalloc(sizeof(*table), GFP_KERNEL);
  46         if (!table)
  47                 return -ENOMEM;
  48         ret = sg_alloc_table(table, num_chunks, GFP_KERNEL);
  49         if (ret) {
  50                 kfree(table);
  51                 return ret;
  52         }
  53
  54         sg = table->sgl;
  55         for (i = 0; i < num_chunks; i++) {
  56                 unsigned long paddr = gen_pool_alloc(chunk_heap->pool,
  57                                                      chunk_heap->chunk_size);
  58                 if (!paddr)
  59                         goto err;
  60                 sg_set_page(sg, pfn_to_page(PFN_DOWN(paddr)),
  61                             chunk_heap->chunk_size, 0);
  62                 sg = sg_next(sg);
  63         }
  64
  65         buffer->sg_table = table;
  66         chunk_heap->allocated += allocated_size;
  67         return 0;
  68 err:
  69         sg = table->sgl;
  70         for (i -= 1; i >= 0; i--) {
  71                 gen_pool_free(chunk_heap->pool, page_to_phys(sg_page(sg)),
  72                               sg->length);
  73                 sg = sg_next(sg);
  74         }
  75         sg_free_table(table);
  76         kfree(table);
  77         return -ENOMEM;
  78 }
  79
  80 static void ion_chunk_heap_free(struct ion_buffer *buffer)
  81 {
  82         struct ion_heap *heap = buffer->heap;
  83         struct ion_chunk_heap *chunk_heap =
  84                 container_of(heap, struct ion_chunk_heap, heap);
  85         struct sg_table *table = buffer->sg_table;
  86         struct scatterlist *sg;
  87         int i;
  88         unsigned long allocated_size;
  89
  90         allocated_size = ALIGN(buffer->size, chunk_heap->chunk_size);
  91
  92         ion_heap_buffer_zero(buffer);
  93
  94         for_each_sg(table->sgl, sg, table->nents, i) {
  95                 gen_pool_free(chunk_heap->pool, page_to_phys(sg_page(sg)),
  96                               sg->length);
  97         }
  98         chunk_heap->allocated -= allocated_size;
  99         sg_free_table(table);
 100         kfree(table);
 101 }
 102
 103 static struct ion_heap_ops chunk_heap_ops = {
 104         .allocate = ion_chunk_heap_allocate,
 105         .free = ion_chunk_heap_free,
 106         .map_user = ion_heap_map_user,
 107         .map_kernel = ion_heap_map_kernel,
 108         .unmap_kernel = ion_heap_unmap_kernel,
 109 };
 110
 111 struct ion_heap *ion_chunk_heap_create(struct ion_platform_heap *heap_data)
 112 {
 113         struct ion_chunk_heap *chunk_heap;
 114         int ret;
 115         struct page *page;
 116         size_t size;
 117
 118         page = pfn_to_page(PFN_DOWN(heap_data->base));
 119         size = heap_data->size;
 120
 121         ret = ion_heap_pages_zero(page, size, pgprot_writecombine(PAGE_KERNEL));
 122         if (ret)
 123                 return ERR_PTR(ret);
 124
 125         chunk_heap = kzalloc(sizeof(*chunk_heap), GFP_KERNEL);
 126         if (!chunk_heap)
 127                 return ERR_PTR(-ENOMEM);
 128
 129         chunk_heap->chunk_size = (unsigned long)heap_data->priv;
 130         chunk_heap->pool = gen_pool_create(get_order(chunk_heap->chunk_size) +
 131                                            PAGE_SHIFT, -1);
 132         if (!chunk_heap->pool) {
 133                 ret = -ENOMEM;
 134                 goto error_gen_pool_create;
 135         }
 136         chunk_heap->base = heap_data->base;
 137         chunk_heap->size = heap_data->size;
 138         chunk_heap->allocated = 0;
 139
 140         gen_pool_add(chunk_heap->pool, chunk_heap->base, heap_data->size, -1);
 141         chunk_heap->heap.ops = &chunk_heap_ops;
 142         chunk_heap->heap.type = ION_HEAP_TYPE_CHUNK;
 143         chunk_heap->heap.flags = ION_HEAP_FLAG_DEFER_FREE;
 144         pr_debug("%s: base %pa size %zu\n", __func__,
 145                  &chunk_heap->base, heap_data->size);
 146
 147         return &chunk_heap->heap;
 148
 149 error_gen_pool_create:
 150         kfree(chunk_heap);
 151         return ERR_PTR(ret);
 152 }
 153