[PATCH v6 07/10] tee: add tee_shm_alloc_cma_phys_mem()

[Jens Wiklander]

Add tee_shm_alloc_cma_phys_mem() to allocate a physical memory using
from the default CMA pool. The memory is represented by a tee_shm object
using the new flag TEE_SHM_CMA_BUF to identify it as physical memory
from CMA.

Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
---
 drivers/tee/tee_shm.c    | 55 ++++++++++++++++++++++++++++++++++++++--
 include/linux/tee_core.h |  4 +++
 2 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index 8b79918468b5..8d8341f8ebd7 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -3,8 +3,11 @@
  * Copyright (c) 2015-2017, 2019-2021 Linaro Limited
  */
 #include <linux/anon_inodes.h>
+#include <linux/cma.h>
 #include <linux/device.h>
 #include <linux/dma-buf.h>
+#include <linux/dma-map-ops.h>
+#include <linux/highmem.h>
 #include <linux/idr.h>
 #include <linux/io.h>
 #include <linux/mm.h>
@@ -13,7 +16,6 @@
 #include <linux/tee_core.h>
 #include <linux/uaccess.h>
 #include <linux/uio.h>
-#include <linux/highmem.h>
 #include "tee_private.h"
 
 /* extra references appended to shm object for registered shared memory */
@@ -59,7 +61,14 @@ static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
 	struct tee_shm *parent_shm = NULL;
 	void *p = shm;
 
-	if (shm->flags & TEE_SHM_DMA_BUF) {
+	if (shm->flags & TEE_SHM_CMA_BUF) {
+#if !IS_MODULE(CONFIG_TEE) && IS_ENABLED(CONFIG_CMA)
+		struct page *page = phys_to_page(shm->paddr);
+		struct cma *cma = dev_get_cma_area(&shm->ctx->teedev->dev);
+
+		cma_release(cma, page, shm->size / PAGE_SIZE);
+#endif
+	} else if (shm->flags & TEE_SHM_DMA_BUF) {
 		struct tee_shm_dmabuf_ref *ref;
 
 		ref = container_of(shm, struct tee_shm_dmabuf_ref, shm);
@@ -341,6 +350,48 @@ struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size)
 }
 EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf);
 
+struct tee_shm *tee_shm_alloc_cma_phys_mem(struct tee_context *ctx,
+					   size_t page_count, size_t align)
+{
+#if !IS_MODULE(CONFIG_TEE) && IS_ENABLED(CONFIG_CMA)
+	struct tee_device *teedev = ctx->teedev;
+	struct cma *cma = dev_get_cma_area(&teedev->dev);
+	struct tee_shm *shm;
+	struct page *page;
+
+	if (!tee_device_get(teedev))
+		return ERR_PTR(-EINVAL);
+
+	page = cma_alloc(cma, page_count, align, true/*no_warn*/);
+	if (!page)
+		goto err_put_teedev;
+
+	shm = kzalloc(sizeof(*shm), GFP_KERNEL);
+	if (!shm)
+		goto err_cma_crelease;
+
+	refcount_set(&shm->refcount, 1);
+	shm->ctx = ctx;
+	shm->paddr = page_to_phys(page);
+	shm->size = page_count * PAGE_SIZE;
+	shm->flags = TEE_SHM_CMA_BUF;
+
+	teedev_ctx_get(ctx);
+
+	return shm;
+
+err_cma_crelease:
+	cma_release(cma, page, page_count);
+err_put_teedev:
+	tee_device_put(teedev);
+
+	return ERR_PTR(-ENOMEM);
+#else
+	return ERR_PTR(-EINVAL);
+#endif
+}
+EXPORT_SYMBOL_GPL(tee_shm_alloc_cma_phys_mem);
+
 int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align,
 			     int (*shm_register)(struct tee_context *ctx,
 						 struct tee_shm *shm,
diff --git a/include/linux/tee_core.h b/include/linux/tee_core.h
index 6bd833b6d0e1..b6727d9a3556 100644
--- a/include/linux/tee_core.h
+++ b/include/linux/tee_core.h
@@ -29,6 +29,7 @@
 #define TEE_SHM_POOL		BIT(2)  /* Memory allocated from pool */
 #define TEE_SHM_PRIV		BIT(3)  /* Memory private to TEE driver */
 #define TEE_SHM_DMA_BUF		BIT(4)	/* Memory with dma-buf handle */
+#define TEE_SHM_CMA_BUF		BIT(5)	/* CMA allocated memory */
 
 #define TEE_DEVICE_FLAG_REGISTERED	0x1
 #define TEE_MAX_DEV_NAME_LEN		32
@@ -307,6 +308,9 @@ void *tee_get_drvdata(struct tee_device *teedev);
  */
 struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size);
 
+struct tee_shm *tee_shm_alloc_cma_phys_mem(struct tee_context *ctx,
+					   size_t page_count, size_t align);
+
 int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align,
 			     int (*shm_register)(struct tee_context *ctx,
 						 struct tee_shm *shm,
-- 
2.43.0