Hi John, On Tue, May 26, 2020 at 1:32 AM John Hubbard <jhubbard@xxxxxxxxxx> wrote: > > This code was using get_user_pages*(), in a "Case 2" scenario > (DMA/RDMA), using the categorization from [1]. That means that it's > time to convert the get_user_pages*() + put_page() calls to > pin_user_pages*() + unpin_user_pages() calls. > > There is some helpful background in [2]: basically, this is a small > part of fixing a long-standing disconnect between pinning pages, and > file systems' use of those pages. > > [1] Documentation/core-api/pin_user_pages.rst > > [2] "Explicit pinning of user-space pages": > https://lwn.net/Articles/807108/ > > Cc: Jens Wiklander <jens.wiklander@xxxxxxxxxx> > Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx> > Cc: tee-dev@xxxxxxxxxxxxxxxx > Cc: linux-media@xxxxxxxxxxxxxxx > Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx > Cc: linaro-mm-sig@xxxxxxxxxxxxxxxx > Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx> > --- > > Hi, > > This fixes the typo ("convert convert") in the subject line, but > otherwise no changes. > > thanks, > John Hubbard > NVIDIA > > > drivers/tee/tee_shm.c | 12 +++--------- > 1 file changed, 3 insertions(+), 9 deletions(-) Looks good. I've tested this on a HiKey 620 board, no regressions. I'm picking up this patch. Thanks, Jens > > diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c > index bd679b72bd05..7dffc42d8d5a 100644 > --- a/drivers/tee/tee_shm.c > +++ b/drivers/tee/tee_shm.c > @@ -31,16 +31,13 @@ static void tee_shm_release(struct tee_shm *shm) > > poolm->ops->free(poolm, shm); > } else if (shm->flags & TEE_SHM_REGISTER) { > - size_t n; > int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm); > > if (rc) > dev_err(teedev->dev.parent, > "unregister shm %p failed: %d", shm, rc); > > - for (n = 0; n < shm->num_pages; n++) > - put_page(shm->pages[n]); > - > + unpin_user_pages(shm->pages, shm->num_pages); > kfree(shm->pages); > } > > @@ -226,7 +223,7 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr, > goto err; > } > > - rc = get_user_pages_fast(start, num_pages, FOLL_WRITE, shm->pages); > + rc = pin_user_pages_fast(start, num_pages, FOLL_WRITE, shm->pages); > if (rc > 0) > shm->num_pages = rc; > if (rc != num_pages) { > @@ -271,16 +268,13 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr, > return shm; > err: > if (shm) { > - size_t n; > - > if (shm->id >= 0) { > mutex_lock(&teedev->mutex); > idr_remove(&teedev->idr, shm->id); > mutex_unlock(&teedev->mutex); > } > if (shm->pages) { > - for (n = 0; n < shm->num_pages; n++) > - put_page(shm->pages[n]); > + unpin_user_pages(shm->pages, shm->num_pages); > kfree(shm->pages); > } > } > -- > 2.26.2 > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
