[PATCH v4 7/7] dma_buf: heaps: restricted_heap_mtk: Add a new CMA heap

Yong Wu
2024-01-12T09:22:27Z

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" restricted heap, "struct cma *cma" is a common property,
not just for MediaTek, so put it into "struct restricted_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/restricted_heap.h | 4 +
drivers/dma-buf/heaps/restricted_heap_mtk.c | 120 +++++++++++++++++++-
3 files changed, 123 insertions(+), 3 deletions(-)

diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
index 84f748fb2856..58903bc62ac8 100644
--- a/drivers/dma-buf/heaps/Kconfig
+++ b/drivers/dma-buf/heaps/Kconfig
@@ -24,7 +24,7 @@ config DMABUF_HEAPS_RESTRICTED

config DMABUF_HEAPS_RESTRICTED_MTK
bool "MediaTek DMA-BUF Restricted Heap"
- depends on DMABUF_HEAPS_RESTRICTED && TEE=y
+ depends on DMABUF_HEAPS_RESTRICTED && DMA_CMA && TEE=y
help
Enable restricted 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/restricted_heap.h b/drivers/dma-buf/heaps/restricted_heap.h
index 6c93f6d257dc..8d17c39b65de 100644
--- a/drivers/dma-buf/heaps/restricted_heap.h
+++ b/drivers/dma-buf/heaps/restricted_heap.h
@@ -21,6 +21,10 @@ struct restricted_heap {

const struct restricted_heap_ops *ops;

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

diff --git a/drivers/dma-buf/heaps/restricted_heap_mtk.c b/drivers/dma-buf/heaps/restricted_heap_mtk.c
index 902add95bb7e..0180d04076e2 100644
--- a/drivers/dma-buf/heaps/restricted_heap_mtk.c
+++ b/drivers/dma-buf/heaps/restricted_heap_mtk.c
@@ -4,9 +4,11 @@
*
* Copyright (C) 2024 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_restricted_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)
@@ -125,6 +139,10 @@ static int mtk_tee_restrict_memory(struct restricted_heap *heap, struct restrict
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 (heap->cma && data->mem_type == MTK_SECURE_MEMORY_TYPE_CM_CMA) {
+ params[2].u.value.a = heap->cma_paddr;
+ params[2].u.value.b = 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);
@@ -163,6 +181,48 @@ mtk_restricted_memory_free(struct restricted_heap *heap, struct restricted_buffe
{
}

+static int mtk_restricted_memory_cma_allocate(struct restricted_heap *heap,
+ struct restricted_buffer *buf)
+{
+ struct mtk_restricted_heap_data *data = 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(heap->cma, 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 + buf->size > heap->cma_size) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ data->cma_used_size += buf->size;
+
+out_unlock:
+ mutex_unlock(&data->lock);
+ return ret;
+}
+
+static void mtk_restricted_memory_cma_free(struct restricted_heap *heap,
+ struct restricted_buffer *buf)
+{
+ struct mtk_restricted_heap_data *data = heap->priv_data;
+
+ mutex_lock(&data->lock);
+ data->cma_used_size -= buf->size;
+ if (!data->cma_used_size)
+ cma_release(heap->cma, data->cma_page,
+ heap->cma_size >> PAGE_SHIFT);
+ mutex_unlock(&data->lock);
+}
+
static int mtk_restricted_heap_init(struct restricted_heap *heap)
{
struct mtk_restricted_heap_data *data = heap->priv_data;
@@ -184,21 +244,77 @@ static struct mtk_restricted_heap_data mtk_restricted_heap_data = {
.mem_type = MTK_SECURE_MEMORY_TYPE_CM_TZ,
};

+static const struct restricted_heap_ops mtk_restricted_heap_ops_cma = {
+ .heap_init = mtk_restricted_heap_init,
+ .memory_alloc = mtk_restricted_memory_cma_allocate,
+ .memory_free = mtk_restricted_memory_cma_free,
+ .memory_restrict = mtk_tee_restrict_memory,
+ .memory_unrestrict = mtk_tee_unrestrict_memory,
+};
+
+static struct mtk_restricted_heap_data mtk_restricted_heap_data_cma = {
+ .mem_type = MTK_SECURE_MEMORY_TYPE_CM_CMA,
+};
+
static struct restricted_heap mtk_restricted_heaps[] = {
{
.name = "restricted_mtk_cm",
.ops = &mtk_restricted_heap_ops,
.priv_data = &mtk_restricted_heap_data,
},
+ {
+ .name = "restricted_mtk_cma",
+ .ops = &mtk_restricted_heap_ops_cma,
+ .priv_data = &mtk_restricted_heap_data_cma,
+ },
};

+static int __init mtk_restricted_cma_init(struct reserved_mem *rmem)
+{
+ struct restricted_heap *rstrd_heap = mtk_restricted_heaps, *rstrd_heap_cma = NULL;
+ struct mtk_restricted_heap_data *data;
+ struct cma *cma;
+ int ret, i;
+
+ for (i = 0; i < ARRAY_SIZE(mtk_restricted_heaps); i++, rstrd_heap++) {
+ data = rstrd_heap->priv_data;
+ if (data->mem_type == MTK_SECURE_MEMORY_TYPE_CM_CMA) {
+ rstrd_heap_cma = rstrd_heap;
+ break;
+ }
+ }
+ if (!rstrd_heap_cma)
+ return -EINVAL;
+
+ ret = cma_init_reserved_mem(rmem->base, rmem->size, 0, rmem->name,
+ &cma);
+ if (ret) {
+ pr_err("%s: %s set up CMA fail\n", __func__, rmem->name);
+ return ret;
+ }
+
+ rstrd_heap_cma->cma = cma;
+ rstrd_heap_cma->cma_paddr = rmem->base;
+ rstrd_heap_cma->cma_size = rmem->size;
+ return 0;
+}
+
+RESERVEDMEM_OF_DECLARE(restricted_cma, "mediatek,dynamic-restricted-region",
+ mtk_restricted_cma_init);
+
static int mtk_restricted_heap_initialize(void)
{
struct restricted_heap *rstrd_heap = mtk_restricted_heaps;
+ struct mtk_restricted_heap_data *data;
unsigned int i;

- for (i = 0; i < ARRAY_SIZE(mtk_restricted_heaps); i++, rstrd_heap++)
- restricted_heap_add(rstrd_heap);
+ for (i = 0; i < ARRAY_SIZE(mtk_restricted_heaps); i++, rstrd_heap++) {
+ data = rstrd_heap->priv_data;
+ if (data->mem_type == MTK_SECURE_MEMORY_TYPE_CM_CMA && !rstrd_heap->cma)
+ continue;
+ if (!restricted_heap_add(rstrd_heap))
+ mutex_init(&data->lock);
+ }
return 0;
}
module_init(mtk_restricted_heap_initialize);
--
2.25.1