1. Patchew
  2. linux
  3. [PATCH v8 00/14] TEE subsystem for protected dma-buf allocations
  4. View patch

[PATCH v8 11/14] tee: add tee_shm_alloc_cma_phys_mem()

Jens Wiklander posted 14 patches 7 months, 2 weeks ago
There is a newer version of this series
[PATCH v8 11/14] tee: add tee_shm_alloc_cma_phys_mem()
Posted by Jens Wiklander 7 months, 2 weeks ago 
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@linaro.org>
---
 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 e1ed52ee0a16..faaa0a87bb18 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"
 
 static void shm_put_kernel_pages(struct page **pages, size_t page_count)
@@ -49,7 +51,14 @@ 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_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);
@@ -306,6 +315,48 @@ 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_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 02c07f661349..3a4e1b00fcc7 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
@@ -310,6 +311,9 @@ 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
Re: [PATCH v8 11/14] tee: add tee_shm_alloc_cma_phys_mem()
Posted by Robin Murphy 7 months, 2 weeks ago 
On 02/05/2025 10:59 am, Jens Wiklander wrote:
> 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.

If and when it's possible to dynamically delegate any old kernel memory 
to the TEE, it's far from clear why that should involve poking around in 
CMA internals...

> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
> ---
>   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 e1ed52ee0a16..faaa0a87bb18 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"
>   
>   static void shm_put_kernel_pages(struct page **pages, size_t page_count)
> @@ -49,7 +51,14 @@ 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_ENABLED(CONFIG_CMA)
> +		struct page *page = phys_to_page(shm->paddr);
> +		struct cma *cma = dev_get_cma_area(&shm->ctx->teedev->dev);

If you want dma_contiguous_default_area as the commit message implies, 
use dma_contiguous_default_area. Appearing to support per-device CMA 
pools but relying on the device not having one is pretty yucky.

But again, why? If you want page-backed DMA-able memory, with all the 
other assumptions being made here, you may as well just rely on 
dma_alloc_pages(DMA_ATTR_SKIP_CPU_SYNC) doing what you want, while also 
being potentially more flexible for !CMA and non-invasive. Or at the 
very least, could the TEE delegation not be composed on top of the 
existing CMA heap allocator?

Thanks,
Robin.

> +
> +		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);
> @@ -306,6 +315,48 @@ 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_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 02c07f661349..3a4e1b00fcc7 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
> @@ -310,6 +311,9 @@ 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,
Re: [PATCH v8 11/14] tee: add tee_shm_alloc_cma_phys_mem()
Posted by Jens Wiklander 7 months, 2 weeks ago 
Hi,

On Fri, May 2, 2025 at 5:11 PM Robin Murphy <robin.murphy@arm.com> wrote:
>
> On 02/05/2025 10:59 am, Jens Wiklander wrote:
> > 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.
>
> If and when it's possible to dynamically delegate any old kernel memory
> to the TEE, it's far from clear why that should involve poking around in
> CMA internals...
>
> > Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
> > ---
> >   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 e1ed52ee0a16..faaa0a87bb18 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"
> >
> >   static void shm_put_kernel_pages(struct page **pages, size_t page_count)
> > @@ -49,7 +51,14 @@ 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_ENABLED(CONFIG_CMA)
> > +             struct page *page = phys_to_page(shm->paddr);
> > +             struct cma *cma = dev_get_cma_area(&shm->ctx->teedev->dev);
>
> If you want dma_contiguous_default_area as the commit message implies,
> use dma_contiguous_default_area. Appearing to support per-device CMA
> pools but relying on the device not having one is pretty yucky.
>
> But again, why? If you want page-backed DMA-able memory, with all the
> other assumptions being made here, you may as well just rely on
> dma_alloc_pages(DMA_ATTR_SKIP_CPU_SYNC) doing what you want, while also
> being potentially more flexible for !CMA and non-invasive. Or at the
> very least, could the TEE delegation not be composed on top of the
> existing CMA heap allocator?

Thanks for suggesting dma_alloc_pages(). I'll use that in the next
version of the patch set.

Cheers,
Jens

>
> Thanks,
> Robin.
>
> > +
> > +             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);
> > @@ -306,6 +315,48 @@ 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_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 02c07f661349..3a4e1b00fcc7 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
> > @@ -310,6 +311,9 @@ 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,

Patchew 2.1-devel-b67e4c2

© 2016 - 2025 Red Hat, Inc.