On Wed, Jun 18, 2025 at 09:03:00AM +0200, Jens Wiklander wrote:
> On Tue, Jun 17, 2025 at 1:32 PM Sumit Garg <sumit.g...@kernel.org> wrote:
> >
> > On Tue, Jun 10, 2025 at 03:13:50PM +0200, Jens Wiklander wrote:
> > > Add tee_shm_alloc_dma_mem() to allocate DMA memory. The memory is
> > > represented by a tee_shm object using the new flag TEE_SHM_DMA_MEM to
> > > identify it as DMA memory. The allocated memory will later be lent to
> > > the TEE to be used as protected memory.
> > >
> > > Signed-off-by: Jens Wiklander <jens.wiklan...@linaro.org>
> > > ---
> > > drivers/tee/tee_shm.c | 85 +++++++++++++++++++++++++++++++++++++++-
> > > include/linux/tee_core.h | 5 +++
> > > 2 files changed, 88 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
> > > index e63095e84644..60b0f3932cee 100644
> > > --- a/drivers/tee/tee_shm.c
> > > +++ b/drivers/tee/tee_shm.c
> > > @@ -5,6 +5,8 @@
> > > #include <linux/anon_inodes.h>
> > > #include <linux/device.h>
> > > #include <linux/dma-buf.h>
> > > +#include <linux/dma-mapping.h>
> > > +#include <linux/highmem.h>
> > > #include <linux/idr.h>
> > > #include <linux/io.h>
> > > #include <linux/mm.h>
> > > @@ -13,9 +15,14 @@
> > > #include <linux/tee_core.h>
> > > #include <linux/uaccess.h>
> > > #include <linux/uio.h>
> > > -#include <linux/highmem.h>
> > > #include "tee_private.h"
> > >
> > > +struct tee_shm_dma_mem {
> > > + struct tee_shm shm;
> > > + dma_addr_t dma_addr;
> > > + struct page *page;
> > > +};
> > > +
> > > static void shm_put_kernel_pages(struct page **pages, size_t page_count)
> > > {
> > > size_t n;
> > > @@ -48,7 +55,16 @@ static void tee_shm_release(struct tee_device *teedev,
> > > struct tee_shm *shm)
> > > {
> > > void *p = shm;
> > >
> > > - if (shm->flags & TEE_SHM_DMA_BUF) {
> > > + if (shm->flags & TEE_SHM_DMA_MEM) {
> > > +#if IS_ENABLED(CONFIG_TEE_DMABUF_HEAPS)
> >
> > nit: this config check can be merged into the above if check.
>
> No, because dma_free_pages() is only defined if
> CONFIG_TEE_DMABUF_HEAPS is enabled.
It looks like you misunderstood my above comment, I rather meant:
if (IS_ENABLED(CONFIG_TEE_DMABUF_HEAPS) &&
(shm->flags & TEE_SHM_DMA_MEM))
-Sumit
>
> >
> > > + struct tee_shm_dma_mem *dma_mem;
> > > +
> > > + dma_mem = container_of(shm, struct tee_shm_dma_mem, shm);
> > > + p = dma_mem;
> > > + dma_free_pages(&teedev->dev, shm->size, dma_mem->page,
> > > + dma_mem->dma_addr, DMA_BIDIRECTIONAL);
> > > +#endif
> > > + } else if (shm->flags & TEE_SHM_DMA_BUF) {
> >
> > Do we need a similar config check for this flag too?
>
> No, because DMA_SHARED_BUFFER is selected, so the dma_buf functions are
> defined.
>
> Cheers,
> Jens
>
>
> >
> > With these addressed, feel free to add:
> >
> > Reviewed-by: Sumit Garg <sumit.g...@oss.qualcomm.com>
> >
> > -Sumit
> >
> > > struct tee_shm_dmabuf_ref *ref;
> > >
> > > ref = container_of(shm, struct tee_shm_dmabuf_ref, shm);
> > > @@ -303,6 +319,71 @@ struct tee_shm *tee_shm_alloc_priv_buf(struct
> > > tee_context *ctx, size_t size)
> > > }
> > > EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf);
> > >
> > > +#if IS_ENABLED(CONFIG_TEE_DMABUF_HEAPS)
> > > +/**
> > > + * tee_shm_alloc_dma_mem() - Allocate DMA memory as shared memory object
> > > + * @ctx: Context that allocates the shared memory
> > > + * @page_count: Number of pages
> > > + *
> > > + * The allocated memory is expected to be lent (made inaccessible to the
> > > + * kernel) to the TEE while it's used and returned (accessible to the
> > > + * kernel again) before it's freed.
> > > + *
> > > + * This function should normally only be used internally in the TEE
> > > + * drivers.
> > > + *
> > > + * @returns a pointer to 'struct tee_shm'
> > > + */
> > > +struct tee_shm *tee_shm_alloc_dma_mem(struct tee_context *ctx,
> > > + size_t page_count)
> > > +{
> > > + struct tee_device *teedev = ctx->teedev;
> > > + struct tee_shm_dma_mem *dma_mem;
> > > + dma_addr_t dma_addr;
> > > + struct page *page;
> > > +
> > > + if (!tee_device_get(teedev))
> > > + return ERR_PTR(-EINVAL);
> > > +
> > > + page = dma_alloc_pages(&teedev->dev, page_count * PAGE_SIZE,
> > > + &dma_addr, DMA_BIDIRECTIONAL, GFP_KERNEL);
> > > + if (!page)
> > > + goto err_put_teedev;
> > > +
> > > + dma_mem = kzalloc(sizeof(*dma_mem), GFP_KERNEL);
> > > + if (!dma_mem)
> > > + goto err_free_pages;
> > > +
> > > + refcount_set(&dma_mem->shm.refcount, 1);
> > > + dma_mem->shm.ctx = ctx;
> > > + dma_mem->shm.paddr = page_to_phys(page);
> > > + dma_mem->dma_addr = dma_addr;
> > > + dma_mem->page = page;
> > > + dma_mem->shm.size = page_count * PAGE_SIZE;
> > > + dma_mem->shm.flags = TEE_SHM_DMA_MEM;
> > > +
> > > + teedev_ctx_get(ctx);
> > > +
> > > + return &dma_mem->shm;
> > > +
> > > +err_free_pages:
> > > + dma_free_pages(&teedev->dev, page_count * PAGE_SIZE, page, dma_addr,
> > > + DMA_BIDIRECTIONAL);
> > > +err_put_teedev:
> > > + tee_device_put(teedev);
> > > +
> > > + return ERR_PTR(-ENOMEM);
> > > +}
> > > +EXPORT_SYMBOL_GPL(tee_shm_alloc_dma_mem);
> > > +#else
> > > +struct tee_shm *tee_shm_alloc_dma_mem(struct tee_context *ctx,
> > > + size_t page_count)
> > > +{
> > > + return ERR_PTR(-EINVAL);
> > > +}
> > > +EXPORT_SYMBOL_GPL(tee_shm_alloc_dma_mem);
> > > +#endif
> > > +
> > > 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 f17710196c4c..e46a53e753af 100644
> > > --- a/include/linux/tee_core.h
> > > +++ b/include/linux/tee_core.h
> > > @@ -29,6 +29,8 @@
> > > #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_DMA_MEM BIT(5) /* Memory allocated with */
> > > + /* dma_alloc_pages() */
> > >
> > > #define TEE_DEVICE_FLAG_REGISTERED 0x1
> > > #define TEE_MAX_DEV_NAME_LEN 32
> > > @@ -310,6 +312,9 @@ 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_dma_mem(struct tee_context *ctx,
> > > + size_t page_count);
> > > +
> > > 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
> > >
