root/drivers/staging/android/ion/ion_cma_heap.c

DEFINITIONS

1. ion_cma_allocate
2. ion_cma_free
3. __ion_cma_heap_create
4. __ion_add_cma_heaps
5. ion_add_cma_heaps

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * ION Memory Allocator CMA heap exporter
   4  *
   5  * Copyright (C) Linaro 2012
   6  * Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
   7  */
   8 
   9 #include <linux/device.h>
  10 #include <linux/slab.h>
  11 #include <linux/errno.h>
  12 #include <linux/err.h>
  13 #include <linux/cma.h>
  14 #include <linux/scatterlist.h>
  15 #include <linux/highmem.h>
  16 
  17 #include "ion.h"
  18 
  19 struct ion_cma_heap {
  20         struct ion_heap heap;
  21         struct cma *cma;
  22 };
  23 
  24 #define to_cma_heap(x) container_of(x, struct ion_cma_heap, heap)
  25 
  26 /* ION CMA heap operations functions */
  27 static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer,
  28                             unsigned long len,
  29                             unsigned long flags)
  30 {
  31         struct ion_cma_heap *cma_heap = to_cma_heap(heap);
  32         struct sg_table *table;
  33         struct page *pages;
  34         unsigned long size = PAGE_ALIGN(len);
  35         unsigned long nr_pages = size >> PAGE_SHIFT;
  36         unsigned long align = get_order(size);
  37         int ret;
  38 
  39         if (align > CONFIG_CMA_ALIGNMENT)
  40                 align = CONFIG_CMA_ALIGNMENT;
  41 
  42         pages = cma_alloc(cma_heap->cma, nr_pages, align, false);
  43         if (!pages)
  44                 return -ENOMEM;
  45 
  46         if (PageHighMem(pages)) {
  47                 unsigned long nr_clear_pages = nr_pages;
  48                 struct page *page = pages;
  49 
  50                 while (nr_clear_pages > 0) {
  51                         void *vaddr = kmap_atomic(page);
  52 
  53                         memset(vaddr, 0, PAGE_SIZE);
  54                         kunmap_atomic(vaddr);
  55                         page++;
  56                         nr_clear_pages--;
  57                 }
  58         } else {
  59                 memset(page_address(pages), 0, size);
  60         }
  61 
  62         table = kmalloc(sizeof(*table), GFP_KERNEL);
  63         if (!table)
  64                 goto err;
  65 
  66         ret = sg_alloc_table(table, 1, GFP_KERNEL);
  67         if (ret)
  68                 goto free_mem;
  69 
  70         sg_set_page(table->sgl, pages, size, 0);
  71 
  72         buffer->priv_virt = pages;
  73         buffer->sg_table = table;
  74         return 0;
  75 
  76 free_mem:
  77         kfree(table);
  78 err:
  79         cma_release(cma_heap->cma, pages, nr_pages);
  80         return -ENOMEM;
  81 }
  82 
  83 static void ion_cma_free(struct ion_buffer *buffer)
  84 {
  85         struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap);
  86         struct page *pages = buffer->priv_virt;
  87         unsigned long nr_pages = PAGE_ALIGN(buffer->size) >> PAGE_SHIFT;
  88 
  89         /* release memory */
  90         cma_release(cma_heap->cma, pages, nr_pages);
  91         /* release sg table */
  92         sg_free_table(buffer->sg_table);
  93         kfree(buffer->sg_table);
  94 }
  95 
  96 static struct ion_heap_ops ion_cma_ops = {
  97         .allocate = ion_cma_allocate,
  98         .free = ion_cma_free,
  99         .map_user = ion_heap_map_user,
 100         .map_kernel = ion_heap_map_kernel,
 101         .unmap_kernel = ion_heap_unmap_kernel,
 102 };
 103 
 104 static struct ion_heap *__ion_cma_heap_create(struct cma *cma)
 105 {
 106         struct ion_cma_heap *cma_heap;
 107 
 108         cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
 109 
 110         if (!cma_heap)
 111                 return ERR_PTR(-ENOMEM);
 112 
 113         cma_heap->heap.ops = &ion_cma_ops;
 114         cma_heap->cma = cma;
 115         cma_heap->heap.type = ION_HEAP_TYPE_DMA;
 116         return &cma_heap->heap;
 117 }
 118 
 119 static int __ion_add_cma_heaps(struct cma *cma, void *data)
 120 {
 121         struct ion_heap *heap;
 122 
 123         heap = __ion_cma_heap_create(cma);
 124         if (IS_ERR(heap))
 125                 return PTR_ERR(heap);
 126 
 127         heap->name = cma_get_name(cma);
 128 
 129         ion_device_add_heap(heap);
 130         return 0;
 131 }
 132 
 133 static int ion_add_cma_heaps(void)
 134 {
 135         cma_for_each_area(__ion_add_cma_heaps, NULL);
 136         return 0;
 137 }
 138 device_initcall(ion_add_cma_heaps);