[PATCH v3 7/7] dma_buf: heaps: secure_heap_mtk: Add a new CMA heap

Yong Wu
2023-12-12T02:48:07Z

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.

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

For the "CMA" secure heap, "struct cma *cma" is a common property, not just
for MediaTek, so put it into "struct secure_heap" instead of our private
data.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
drivers/dma-buf/heaps/Kconfig | 2 +-
drivers/dma-buf/heaps/secure_heap.h | 4 +
drivers/dma-buf/heaps/secure_heap_mtk.c | 119 +++++++++++++++++++++++-
3 files changed, 122 insertions(+), 3 deletions(-)

diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
index 12962189878e..f117d91a0a9d 100644
--- a/drivers/dma-buf/heaps/Kconfig
+++ b/drivers/dma-buf/heaps/Kconfig
@@ -21,7 +21,7 @@ config DMABUF_HEAPS_SECURE

config DMABUF_HEAPS_SECURE_MTK
bool "MediaTek DMA-BUF Secure Heap"
- depends on DMABUF_HEAPS_SECURE && TEE=y
+ depends on DMABUF_HEAPS_SECURE && DMA_CMA && TEE=y
help
Enable secure dma-buf heaps for MediaTek platform. This heap is backed by
TEE client interfaces. If in doubt, say N.
diff --git a/drivers/dma-buf/heaps/secure_heap.h b/drivers/dma-buf/heaps/secure_heap.h
index 374fd276bdd7..9f80edcd3e1f 100644
--- a/drivers/dma-buf/heaps/secure_heap.h
+++ b/drivers/dma-buf/heaps/secure_heap.h
@@ -20,6 +20,10 @@ struct secure_heap {

const struct secure_heap_ops *ops;

+ struct cma *cma;
+ unsigned long cma_paddr;
+ unsigned long cma_size;
+
void *priv_data;
};

diff --git a/drivers/dma-buf/heaps/secure_heap_mtk.c b/drivers/dma-buf/heaps/secure_heap_mtk.c
index 2c6aaeaf469f..58148120f4ed 100644
--- a/drivers/dma-buf/heaps/secure_heap_mtk.c
+++ b/drivers/dma-buf/heaps/secure_heap_mtk.c
@@ -4,9 +4,11 @@
*
* Copyright (C) 2023 MediaTek Inc.
*/
+#include <linux/cma.h>
#include <linux/dma-buf.h>
#include <linux/err.h>
#include <linux/module.h>
+#include <linux/of_reserved_mem.h>
#include <linux/slab.h>
#include <linux/tee_drv.h>
#include <linux/uuid.h>
@@ -23,6 +25,13 @@ enum mtk_secure_mem_type {
* management is inside the TEE.
*/
MTK_SECURE_MEMORY_TYPE_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.
+ */
+ MTK_SECURE_MEMORY_TYPE_CM_CMA = 2,
};

enum mtk_secure_buffer_tee_cmd {
@@ -32,6 +41,8 @@ enum mtk_secure_buffer_tee_cmd {
* [in] value[0].a: The buffer size.
* value[0].b: alignment.
* [in] value[1].a: enum mtk_secure_mem_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.
*/
MTK_TZCMD_SECMEM_ZALLOC = 0x10000, /* MTK TEE Command ID Base */
@@ -52,6 +63,9 @@ struct mtk_secure_heap_data {

const enum mtk_secure_mem_type mem_type;

+ struct page *cma_page;
+ unsigned long cma_used_size;
+ struct mutex lock; /* lock for cma_used_size */
};

static int mtk_tee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
@@ -126,6 +140,10 @@ static int mtk_tee_secure_memory(struct secure_heap *sec_heap, struct secure_buf
params[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
params[1].u.value.a = data->mem_type;
params[2].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
+ if (sec_heap->cma && data->mem_type == MTK_SECURE_MEMORY_TYPE_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 = mtk_tee_service_call(data->tee_ctx, data->tee_session,
MTK_TZCMD_SECMEM_ZALLOC, params);
@@ -162,6 +180,48 @@ static void mtk_secure_memory_free(struct secure_heap *sec_heap, struct secure_b
{
}

+static int mtk_secure_memory_cma_allocate(struct secure_heap *sec_heap,
+ struct secure_buffer *sec_buf)
+{
+ struct mtk_secure_heap_data *data = sec_heap->priv_data;
+ int ret = 0;
+ /*
+ * Allocate CMA only when allocating buffer for the first time, and just
+ * increase cma_used_size at the other time, Actually the memory
+ * allocating is within the TEE.
+ */
+ mutex_lock(&data->lock);
+ if (!data->cma_used_size) {
+ data->cma_page = cma_alloc(sec_heap->cma, sec_heap->cma_size >> PAGE_SHIFT,
+ get_order(PAGE_SIZE), false);
+ if (!data->cma_page) {
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
+ } else if (data->cma_used_size + sec_buf->size > sec_heap->cma_size) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ data->cma_used_size += sec_buf->size;
+
+out_unlock:
+ mutex_unlock(&data->lock);
+ return ret;
+}
+
+static void mtk_secure_memory_cma_free(struct secure_heap *sec_heap,
+ struct secure_buffer *sec_buf)
+{
+ struct mtk_secure_heap_data *data = sec_heap->priv_data;
+
+ mutex_lock(&data->lock);
+ data->cma_used_size -= sec_buf->size;
+ if (!data->cma_used_size)
+ cma_release(sec_heap->cma, data->cma_page,
+ sec_heap->cma_size >> PAGE_SHIFT);
+ mutex_unlock(&data->lock);
+}
+
static int mtk_secure_heap_init(struct secure_heap *sec_heap)
{
struct mtk_secure_heap_data *data = sec_heap->priv_data;
@@ -183,21 +243,76 @@ static struct mtk_secure_heap_data mtk_sec_heap_data = {
.mem_type = MTK_SECURE_MEMORY_TYPE_CM_TZ,
};

+static const struct secure_heap_ops mtk_sec_mem_ops_cma = {
+ .heap_init = mtk_secure_heap_init,
+ .memory_alloc = mtk_secure_memory_cma_allocate,
+ .memory_free = mtk_secure_memory_cma_free,
+ .secure_the_memory = mtk_tee_secure_memory,
+ .unsecure_the_memory = mtk_tee_unsecure_memory,
+};
+
+static struct mtk_secure_heap_data mtk_sec_heap_data_cma = {
+ .mem_type = MTK_SECURE_MEMORY_TYPE_CM_CMA,
+};
+
static struct secure_heap mtk_secure_heaps[] = {
{
.name = "secure_mtk_cm",
.ops = &mtk_sec_mem_ops,
.priv_data = &mtk_sec_heap_data,
},
+ {
+ .name = "secure_mtk_cma",
+ .ops = &mtk_sec_mem_ops_cma,
+ .priv_data = &mtk_sec_heap_data_cma,
+ },
};

+static int __init mtk_secure_cma_init(struct reserved_mem *rmem)
+{
+ struct mtk_secure_heap_data *data;
+ struct secure_heap *sec_heap = mtk_secure_heaps, *sec_heap_cma = NULL;
+ struct cma *sec_cma;
+ int ret, i;
+
+ for (i = 0; i < ARRAY_SIZE(mtk_secure_heaps); i++, sec_heap++) {
+ data = sec_heap->priv_data;
+ if (data->mem_type == MTK_SECURE_MEMORY_TYPE_CM_CMA) {
+ sec_heap_cma = sec_heap;
+ break;
+ }
+ }
+ if (!sec_heap_cma)
+ return -EINVAL;
+
+ 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;
+ }
+
+ sec_heap_cma->cma = sec_cma;
+ sec_heap_cma->cma_paddr = rmem->base;
+ sec_heap_cma->cma_size = rmem->size;
+ return 0;
+}
+
+RESERVEDMEM_OF_DECLARE(secure_cma, "mediatek,dynamic-secure-region", mtk_secure_cma_init);
+
static int mtk_sec_heap_init(void)
{
struct secure_heap *sec_heap = mtk_secure_heaps;
+ struct mtk_secure_heap_data *data;
unsigned int i;

- for (i = 0; i < ARRAY_SIZE(mtk_secure_heaps); i++, sec_heap++)
- secure_heap_add(sec_heap);
+ for (i = 0; i < ARRAY_SIZE(mtk_secure_heaps); i++, sec_heap++) {
+ data = sec_heap->priv_data;
+ if (data->mem_type == MTK_SECURE_MEMORY_TYPE_CM_CMA && !sec_heap->cma)
+ continue;
+ if (!secure_heap_add(sec_heap))
+ mutex_init(&data->lock);
+ }
return 0;
}

--
2.25.1