[PATCH v4 4/7] dma-buf: heaps: restricted_heap: Add dma_ops

Yong Wu
2024-01-12T09:21:28Z

Add the dma_ops for this restricted heap. For restricted buffer,
cache_ops/mmap are not allowed, thus return EPERM for them.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
drivers/dma-buf/heaps/restricted_heap.c | 103 ++++++++++++++++++++++++
1 file changed, 103 insertions(+)

diff --git a/drivers/dma-buf/heaps/restricted_heap.c b/drivers/dma-buf/heaps/restricted_heap.c
index 8c266a0f6192..ec4c63d2112d 100644
--- a/drivers/dma-buf/heaps/restricted_heap.c
+++ b/drivers/dma-buf/heaps/restricted_heap.c
@@ -12,6 +12,10 @@

#include "restricted_heap.h"

+struct restricted_heap_attachment {
+ struct sg_table *table;
+};
+
static int
restricted_heap_memory_allocate(struct restricted_heap *heap, struct restricted_buffer *buf)
{
@@ -45,6 +49,104 @@ restricted_heap_memory_free(struct restricted_heap *heap, struct restricted_buff
ops->memory_free(heap, buf);
}

+static int restricted_heap_attach(struct dma_buf *dmabuf, struct dma_buf_attachment *attachment)
+{
+ struct restricted_buffer *restricted_buf = dmabuf->priv;
+ struct restricted_heap_attachment *a;
+ struct sg_table *table;
+ int ret;
+
+ a = kzalloc(sizeof(*a), GFP_KERNEL);
+ if (!a)
+ return -ENOMEM;
+
+ table = kzalloc(sizeof(*table), GFP_KERNEL);
+ if (!table) {
+ ret = -ENOMEM;
+ goto err_free_attach;
+ }
+
+ ret = sg_alloc_table(table, 1, GFP_KERNEL);
+ if (ret)
+ goto err_free_sgt;
+ sg_set_page(table->sgl, NULL, restricted_buf->size, 0);
+
+ a->table = table;
+ attachment->priv = a;
+
+ return 0;
+
+err_free_sgt:
+ kfree(table);
+err_free_attach:
+ kfree(a);
+ return ret;
+}
+
+static void restricted_heap_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attachment)
+{
+ struct restricted_heap_attachment *a = attachment->priv;
+
+ sg_free_table(a->table);
+ kfree(a->table);
+ kfree(a);
+}
+
+static struct sg_table *
+restricted_heap_map_dma_buf(struct dma_buf_attachment *attachment, enum dma_data_direction direct)
+{
+ struct restricted_heap_attachment *a = attachment->priv;
+ struct sg_table *table = a->table;
+
+ return table;
+}
+
+static void
+restricted_heap_unmap_dma_buf(struct dma_buf_attachment *attachment, struct sg_table *table,
+ enum dma_data_direction direction)
+{
+ struct restricted_heap_attachment *a = attachment->priv;
+
+ WARN_ON(a->table != table);
+}
+
+static int
+restricted_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf, enum dma_data_direction direction)
+{
+ return -EPERM;
+}
+
+static int
+restricted_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf, enum dma_data_direction direction)
+{
+ return -EPERM;
+}
+
+static int restricted_heap_dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
+{
+ return -EPERM;
+}
+
+static void restricted_heap_free(struct dma_buf *dmabuf)
+{
+ struct restricted_buffer *restricted_buf = dmabuf->priv;
+ struct restricted_heap *heap = dma_heap_get_drvdata(restricted_buf->heap);
+
+ restricted_heap_memory_free(heap, restricted_buf);
+ kfree(restricted_buf);
+}
+
+static const struct dma_buf_ops restricted_heap_buf_ops = {
+ .attach = restricted_heap_attach,
+ .detach = restricted_heap_detach,
+ .map_dma_buf = restricted_heap_map_dma_buf,
+ .unmap_dma_buf = restricted_heap_unmap_dma_buf,
+ .begin_cpu_access = restricted_heap_dma_buf_begin_cpu_access,
+ .end_cpu_access = restricted_heap_dma_buf_end_cpu_access,
+ .mmap = restricted_heap_dma_buf_mmap,
+ .release = restricted_heap_free,
+};
+
static struct dma_buf *
restricted_heap_allocate(struct dma_heap *heap, unsigned long size,
unsigned long fd_flags, unsigned long heap_flags)
@@ -66,6 +168,7 @@ restricted_heap_allocate(struct dma_heap *heap, unsigned long size,
if (ret)
goto err_free_buf;
exp_info.exp_name = dma_heap_get_name(heap);
+ exp_info.ops = &restricted_heap_buf_ops;
exp_info.size = restricted_buf->size;
exp_info.flags = fd_flags;
exp_info.priv = restricted_buf;
--
2.25.1