[PATCH v2 7/8] dma_buf: heaps: secure_heap: Add a new MediaTek CMA heap

Yong Wu
2023-11-11T11:18:03Z

Create a new MediaTek CMA heap from the CMA reserved buffer.

In this heap, When the first allocating buffer, use cma_alloc to prepare
whole the CMA range, then send its range to TEE to protect and manage.
For the later allocating, we just adds the cma_used_size_mtk.

This CMA flow may be different with the normal CMA heap of next patch.
So I named the variable with _mtk suffix like cma_page_mtk/
cma_used_size_mtk. This is also to distinguish it from the cma_page of
the buffer structure in the next patch.

When SVP done, cma_release will release the buffer, then kernel may
reuse it.

Meanwhile, this patch adds a "heap_init" pointer, while allows some heap
initialization operations. This case also checks if the CMA range is
ready.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
drivers/dma-buf/heaps/secure_heap.c | 124 +++++++++++++++++++++++++++-
1 file changed, 122 insertions(+), 2 deletions(-)

diff --git a/drivers/dma-buf/heaps/secure_heap.c b/drivers/dma-buf/heaps/secure_heap.c
index 25cc95442c56..f8b84fd16288 100644
--- a/drivers/dma-buf/heaps/secure_heap.c
+++ b/drivers/dma-buf/heaps/secure_heap.c
@@ -4,11 +4,12 @@
*
* Copyright (C) 2023 MediaTek Inc.
*/
-
+#include <linux/cma.h>
#include <linux/dma-buf.h>
#include <linux/dma-heap.h>
#include <linux/err.h>
#include <linux/module.h>
+#include <linux/of_reserved_mem.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/tee_drv.h>
@@ -25,6 +26,8 @@ enum secure_buffer_tee_cmd { /* PARAM NUM always is 4. */
* [in] value[0].a: The buffer size.
* value[0].b: alignment.
* [in] value[1].a: enum secure_memory_type.
+ * [in] value[2].a: pa base in cma case.
+ * value[2].b: The buffer size in cma case.
* [out] value[3].a: The secure handle.
*/
TZCMD_SECMEM_ZALLOC = 0,
@@ -45,6 +48,13 @@ enum secure_memory_type {
* management is inside the TEE.
*/
SECURE_MEMORY_TYPE_MTK_CM_TZ = 1,
+ /*
+ * MediaTek dynamic chunk memory carved out from CMA.
+ * In normal case, the CMA could be used in kernel; When SVP start, we will
+ * allocate whole this CMA and pass whole the CMA PA and size into TEE to
+ * protect it, then the detail memory management also is inside the TEE.
+ */
+ SECURE_MEMORY_TYPE_MTK_CM_CMA = 2,
};

struct secure_buffer {
@@ -70,6 +80,7 @@ struct secure_heap_prv_data {
*/
const int tee_command_id_base;

+ int (*heap_init)(struct secure_heap *sec_heap);
int (*memory_alloc)(struct secure_heap *sec_heap, struct secure_buffer *sec_buf);
void (*memory_free)(struct secure_heap *sec_heap, struct secure_buffer *sec_buf);

@@ -86,6 +97,13 @@ struct secure_heap {
u32 tee_session;

const struct secure_heap_prv_data *data;
+
+ struct cma *cma;
+ struct page *cma_page_mtk;
+ unsigned long cma_paddr;
+ unsigned long cma_size;
+ unsigned long cma_used_size_mtk;
+ struct mutex lock; /* lock for cma_used_size_mtk */
};

struct secure_heap_attachment {
@@ -168,7 +186,10 @@ static int secure_heap_tee_secure_memory(struct secure_heap *sec_heap,
params[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
params[1].u.value.a = sec_heap->mem_type;
params[2].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
-
+ if (sec_heap->cma && sec_heap->mem_type == SECURE_MEMORY_TYPE_MTK_CM_CMA) {
+ params[2].u.value.a = sec_heap->cma_paddr;
+ params[2].u.value.b = sec_heap->cma_size;
+ }
params[3].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT;
ret = secure_heap_tee_service_call(sec_heap->tee_ctx, sec_heap->tee_session,
data->tee_command_id_base + TZCMD_SECMEM_ZALLOC,
@@ -197,6 +218,66 @@ static void secure_heap_tee_unsecure_memory(struct secure_heap *sec_heap,
sec_heap->name, sec_buf->sec_handle, params[1].u.value.a);
}

+static int mtk_secure_memory_cma_allocate(struct secure_heap *sec_heap,
+ struct secure_buffer *sec_buf)
+{
+ /*
+ * Allocate CMA only when allocating buffer for the first time, and just
+ * increase cma_used_size_mtk at the other time.
+ */
+ mutex_lock(&sec_heap->lock);
+ if (sec_heap->cma_used_size_mtk)
+ goto add_size;
+
+ mutex_unlock(&sec_heap->lock);
+ sec_heap->cma_page_mtk = cma_alloc(sec_heap->cma, sec_heap->cma_size >> PAGE_SHIFT,
+ get_order(PAGE_SIZE), false);
+ if (!sec_heap->cma_page_mtk)
+ return -ENOMEM;
+
+ mutex_lock(&sec_heap->lock);
+add_size:
+ sec_heap->cma_used_size_mtk += sec_buf->size;
+ mutex_unlock(&sec_heap->lock);
+
+ return 0;
+}
+
+static void mtk_secure_memory_cma_free(struct secure_heap *sec_heap,
+ struct secure_buffer *sec_buf)
+{
+ bool cma_is_empty;
+
+ mutex_lock(&sec_heap->lock);
+ sec_heap->cma_used_size_mtk -= sec_buf->size;
+ cma_is_empty = !sec_heap->cma_used_size_mtk;
+ mutex_unlock(&sec_heap->lock);
+
+ if (cma_is_empty)
+ cma_release(sec_heap->cma, sec_heap->cma_page_mtk,
+ sec_heap->cma_size >> PAGE_SHIFT);
+}
+
+static int mtk_secure_heap_cma_init(struct secure_heap *sec_heap)
+{
+ if (!sec_heap->cma)
+ return -EINVAL;
+ mutex_init(&sec_heap->lock);
+ return 0;
+}
+
+/* Use CMA to prepare the buffer and the memory allocating is within the TEE. */
+const struct secure_heap_prv_data mtk_sec_mem_data_cma = {
+ .uuid = TZ_TA_MEM_UUID_MTK,
+ .tee_impl_id = TEE_IMPL_ID_OPTEE,
+ .tee_command_id_base = TEE_MEM_COMMAND_ID_BASE_MTK,
+ .heap_init = mtk_secure_heap_cma_init,
+ .memory_alloc = mtk_secure_memory_cma_allocate,
+ .memory_free = mtk_secure_memory_cma_free,
+ .secure_the_memory = secure_heap_tee_secure_memory,
+ .unsecure_the_memory = secure_heap_tee_unsecure_memory,
+};
+
/* The memory allocating is within the TEE. */
const struct secure_heap_prv_data mtk_sec_mem_data = {
.uuid = TZ_TA_MEM_UUID_MTK,
@@ -420,20 +501,59 @@ static struct secure_heap secure_heaps[] = {
.mem_type = SECURE_MEMORY_TYPE_MTK_CM_TZ,
.data = &mtk_sec_mem_data,
},
+ {
+ .name = "secure_mtk_cma",
+ .mem_type = SECURE_MEMORY_TYPE_MTK_CM_CMA,
+ .data = &mtk_sec_mem_data_cma,
+ },
};

+static int __init secure_cma_init(struct reserved_mem *rmem)
+{
+ struct secure_heap *sec_heap = secure_heaps;
+ struct cma *sec_cma;
+ int ret, i;
+
+ ret = cma_init_reserved_mem(rmem->base, rmem->size, 0, rmem->name,
+ &sec_cma);
+ if (ret) {
+ pr_err("%s: %s set up CMA fail\n", __func__, rmem->name);
+ return ret;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(secure_heaps); i++, sec_heap++) {
+ if (sec_heap->mem_type != SECURE_MEMORY_TYPE_MTK_CM_CMA)
+ continue;
+
+ sec_heap->cma = sec_cma;
+ sec_heap->cma_paddr = rmem->base;
+ sec_heap->cma_size = rmem->size;
+ }
+ return 0;
+}
+
+RESERVEDMEM_OF_DECLARE(secure_cma, "secure_cma_region", secure_cma_init);
+
static int secure_heap_init(void)
{
struct secure_heap *sec_heap = secure_heaps;
struct dma_heap_export_info exp_info;
struct dma_heap *heap;
unsigned int i;
+ int ret;

for (i = 0; i < ARRAY_SIZE(secure_heaps); i++, sec_heap++) {
exp_info.name = sec_heap->name;
exp_info.ops = &sec_heap_ops;
exp_info.priv = (void *)sec_heap;

+ if (sec_heap->data && sec_heap->data->heap_init) {
+ ret = sec_heap->data->heap_init(sec_heap);
+ if (ret) {
+ pr_err("sec_heap %s init fail %d.\n", sec_heap->name, ret);
+ continue;
+ }
+ }
heap = dma_heap_add(&exp_info);
if (IS_ERR(heap))
return PTR_ERR(heap);
--
2.25.1