[PATCH v4 3/7] dma-buf: heaps: restricted_heap: Add private heap ops

Yong Wu
2024-01-12T09:21:13Z

Add "struct restricted_heap_ops". For the restricted memory, totally there
are two steps:
a) memory_alloc: Allocate the buffer in kernel;
b) memory_restrict: Restrict/Protect/Secure that buffer.
The memory_alloc is mandatory while memory_restrict is optinal since it may
be part of memory_alloc.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
drivers/dma-buf/heaps/restricted_heap.c | 41 ++++++++++++++++++++++++-
drivers/dma-buf/heaps/restricted_heap.h | 12 ++++++++
2 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/drivers/dma-buf/heaps/restricted_heap.c b/drivers/dma-buf/heaps/restricted_heap.c
index fd7c82abd42e..8c266a0f6192 100644
--- a/drivers/dma-buf/heaps/restricted_heap.c
+++ b/drivers/dma-buf/heaps/restricted_heap.c
@@ -12,10 +12,44 @@

#include "restricted_heap.h"

+static int
+restricted_heap_memory_allocate(struct restricted_heap *heap, struct restricted_buffer *buf)
+{
+ const struct restricted_heap_ops *ops = heap->ops;
+ int ret;
+
+ ret = ops->memory_alloc(heap, buf);
+ if (ret)
+ return ret;
+
+ if (ops->memory_restrict) {
+ ret = ops->memory_restrict(heap, buf);
+ if (ret)
+ goto memory_free;
+ }
+ return 0;
+
+memory_free:
+ ops->memory_free(heap, buf);
+ return ret;
+}
+
+static void
+restricted_heap_memory_free(struct restricted_heap *heap, struct restricted_buffer *buf)
+{
+ const struct restricted_heap_ops *ops = heap->ops;
+
+ if (ops->memory_unrestrict)
+ ops->memory_unrestrict(heap, buf);
+
+ ops->memory_free(heap, buf);
+}
+
static struct dma_buf *
restricted_heap_allocate(struct dma_heap *heap, unsigned long size,
unsigned long fd_flags, unsigned long heap_flags)
{
+ struct restricted_heap *restricted_heap = dma_heap_get_drvdata(heap);
struct restricted_buffer *restricted_buf;
DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
struct dma_buf *dmabuf;
@@ -28,6 +62,9 @@ restricted_heap_allocate(struct dma_heap *heap, unsigned long size,
restricted_buf->size = ALIGN(size, PAGE_SIZE);
restricted_buf->heap = heap;

+ ret = restricted_heap_memory_allocate(restricted_heap, restricted_buf);
+ if (ret)
+ goto err_free_buf;
exp_info.exp_name = dma_heap_get_name(heap);
exp_info.size = restricted_buf->size;
exp_info.flags = fd_flags;
@@ -36,11 +73,13 @@ restricted_heap_allocate(struct dma_heap *heap, unsigned long size,
dmabuf = dma_buf_export(&exp_info);
if (IS_ERR(dmabuf)) {
ret = PTR_ERR(dmabuf);
- goto err_free_buf;
+ goto err_free_restricted_mem;
}

return dmabuf;

+err_free_restricted_mem:
+ restricted_heap_memory_free(restricted_heap, restricted_buf);
err_free_buf:
kfree(restricted_buf);
return ERR_PTR(ret);
diff --git a/drivers/dma-buf/heaps/restricted_heap.h b/drivers/dma-buf/heaps/restricted_heap.h
index 443028f6ba3b..ddeaf9805708 100644
--- a/drivers/dma-buf/heaps/restricted_heap.h
+++ b/drivers/dma-buf/heaps/restricted_heap.h
@@ -15,6 +15,18 @@ struct restricted_buffer {

struct restricted_heap {
const char *name;
+
+ const struct restricted_heap_ops *ops;
+};
+
+struct restricted_heap_ops {
+ int (*heap_init)(struct restricted_heap *heap);
+
+ int (*memory_alloc)(struct restricted_heap *heap, struct restricted_buffer *buf);
+ void (*memory_free)(struct restricted_heap *heap, struct restricted_buffer *buf);
+
+ int (*memory_restrict)(struct restricted_heap *heap, struct restricted_buffer *buf);
+ void (*memory_unrestrict)(struct restricted_heap *heap, struct restricted_buffer *buf);
};

int restricted_heap_add(struct restricted_heap *rstrd_heap);
--
2.25.1