| Message ID | 20200824211125.1867329-1-jhubbard@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] tee: convert convert get_user_pages() --> pin_user_pages() | expand |
On Mon, Aug 24, 2020 at 02:11:25PM -0700, John Hubbard 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. > > Factor out a new, small release_registered_pages() function, in > order to consolidate the logic for discerning between > TEE_SHM_USER_MAPPED and TEE_SHM_KERNEL_MAPPED pages. This also > absorbs the kfree() call that is also required there. > > 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@linaro.org> > Cc: Sumit Semwal <sumit.semwal@linaro.org> > Cc: tee-dev@lists.linaro.org > Cc: linux-media@vger.kernel.org > Cc: dri-devel@lists.freedesktop.org > Cc: linaro-mm-sig@lists.linaro.org > Signed-off-by: John Hubbard <jhubbard@nvidia.com> > --- > > OK, one more try, this time actually handling the _USER_MAPPED vs. > _KERNEL_MAPPED pages! > > thanks, > John Hubbard > NVIDIA Looks good and it works too! :-) I've tested it on my Hikey board with the OP-TEE test suite. I'm picking this up. Thanks, Jens
On 8/25/20 1:32 AM, Jens Wiklander wrote: > On Mon, Aug 24, 2020 at 02:11:25PM -0700, John Hubbard wrote: ... >> OK, one more try, this time actually handling the _USER_MAPPED vs. >> _KERNEL_MAPPED pages! >> >> thanks, >> John Hubbard >> NVIDIA > > Looks good and it works too! :-) I've tested it on my Hikey board with > the OP-TEE test suite. > I'm picking this up. > Great! I see that I have, once again, somehow doubled up on the subject line: "tee: convert convert ...". This particular typo just seems to stick to me. :) If you get a chance to fix that up by changing it to just a single "convert" I'd appreciate it. thanks,
On Tue, Aug 25, 2020 at 10:54 AM John Hubbard <jhubbard@nvidia.com> wrote: > > On 8/25/20 1:32 AM, Jens Wiklander wrote: > > On Mon, Aug 24, 2020 at 02:11:25PM -0700, John Hubbard wrote: > ... > >> OK, one more try, this time actually handling the _USER_MAPPED vs. > >> _KERNEL_MAPPED pages! > >> > >> thanks, > >> John Hubbard > >> NVIDIA > > > > Looks good and it works too! :-) I've tested it on my Hikey board with > > the OP-TEE test suite. > > I'm picking this up. > > > > Great! I see that I have, once again, somehow doubled up on the subject line: > "tee: convert convert ...". This particular typo just seems to stick to me. :) > > If you get a chance to fix that up by changing it to just a single "convert" > I'd appreciate it. Sure, no problem. Cheers, Jens
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index 827ac3d0fea9..00472f5ce22e 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -12,6 +12,22 @@ #include <linux/uio.h> #include "tee_private.h" +static void release_registered_pages(struct tee_shm *shm) +{ + if (shm->pages) { + if (shm->flags & TEE_SHM_USER_MAPPED) { + unpin_user_pages(shm->pages, shm->num_pages); + } else { + size_t n; + + for (n = 0; n < shm->num_pages; n++) + put_page(shm->pages[n]); + } + + kfree(shm->pages); + } +} + static void tee_shm_release(struct tee_shm *shm) { struct tee_device *teedev = shm->ctx->teedev; @@ -32,17 +48,13 @@ 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]); - - kfree(shm->pages); + release_registered_pages(shm); } teedev_ctx_put(shm->ctx); @@ -228,7 +240,7 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr, } if (flags & TEE_SHM_USER_MAPPED) { - rc = get_user_pages_fast(start, num_pages, FOLL_WRITE, + rc = pin_user_pages_fast(start, num_pages, FOLL_WRITE, shm->pages); } else { struct kvec *kiov; @@ -292,18 +304,12 @@ 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]); - kfree(shm->pages); - } + release_registered_pages(shm); } kfree(shm); teedev_ctx_put(ctx);
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. Factor out a new, small release_registered_pages() function, in order to consolidate the logic for discerning between TEE_SHM_USER_MAPPED and TEE_SHM_KERNEL_MAPPED pages. This also absorbs the kfree() call that is also required there. 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@linaro.org> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: tee-dev@lists.linaro.org Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Signed-off-by: John Hubbard <jhubbard@nvidia.com> --- OK, one more try, this time actually handling the _USER_MAPPED vs. _KERNEL_MAPPED pages! thanks, John Hubbard NVIDIA drivers/tee/tee_shm.c | 32 +++++++++++++++++++------------- 1 file changed, 19 insertions(+), 13 deletions(-)