On Sat, Oct 10, 2020 at 10:27 PM Oded Gabbay <oded.gabbay@xxxxxxxxx> wrote:
>
> On Fri, Oct 9, 2020 at 10:59 AM Daniel Vetter <daniel.vetter@xxxxxxxx> wrote:
> >
> > All we need are a pages array, pin_user_pages_fast can give us that
> > directly. Plus this avoids the entire raw pfn side of get_vaddr_frames.
> >
> Thanks for the patch Daniel.
>
> > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
> > Cc: Jason Gunthorpe <jgg@xxxxxxxx>
> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> > Cc: John Hubbard <jhubbard@xxxxxxxxxx>
> > Cc: Jérôme Glisse <jglisse@xxxxxxxxxx>
> > Cc: Jan Kara <jack@xxxxxxx>
> > Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> > Cc: linux-mm@xxxxxxxxx
> > Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> > Cc: linux-samsung-soc@xxxxxxxxxxxxxxx
> > Cc: linux-media@xxxxxxxxxxxxxxx
> > Cc: Oded Gabbay <oded.gabbay@xxxxxxxxx>
> > Cc: Omer Shpigelman <oshpigelman@xxxxxxxxx>
> > Cc: Ofir Bitton <obitton@xxxxxxxxx>
> > Cc: Tomer Tayar <ttayar@xxxxxxxxx>
> > Cc: Moti Haimovski <mhaimovski@xxxxxxxxx>
> > Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Cc: Pawel Piskorski <ppiskorski@xxxxxxxxx>
> > --
> > v2: Use unpin_user_pages_dirty_lock (John)
> > ---
> > drivers/misc/habanalabs/Kconfig | 1 -
> > drivers/misc/habanalabs/common/habanalabs.h | 3 +-
> > drivers/misc/habanalabs/common/memory.c | 49 ++++++++-------------
> > 3 files changed, 20 insertions(+), 33 deletions(-)
> >
> > diff --git a/drivers/misc/habanalabs/Kconfig b/drivers/misc/habanalabs/Kconfig
> > index 8eb5d38c618e..2f04187f7167 100644
> > --- a/drivers/misc/habanalabs/Kconfig
> > +++ b/drivers/misc/habanalabs/Kconfig
> > @@ -6,7 +6,6 @@
> > config HABANA_AI
> > tristate "HabanaAI accelerators (habanalabs)"
> > depends on PCI && HAS_IOMEM
> > - select FRAME_VECTOR
> > select DMA_SHARED_BUFFER
> > select GENERIC_ALLOCATOR
> > select HWMON
> > diff --git a/drivers/misc/habanalabs/common/habanalabs.h b/drivers/misc/habanalabs/common/habanalabs.h
> > index edbd627b29d2..c1b3ad613b15 100644
> > --- a/drivers/misc/habanalabs/common/habanalabs.h
> > +++ b/drivers/misc/habanalabs/common/habanalabs.h
> > @@ -881,7 +881,8 @@ struct hl_ctx_mgr {
> > struct hl_userptr {
> > enum vm_type_t vm_type; /* must be first */
> > struct list_head job_node;
> > - struct frame_vector *vec;
> > + struct page **pages;
> > + unsigned int npages;
> Can you please update the kerneldoc comment section of this structure
> according to your changes ?
Apologies I missed the nice kerneldoc. I'll fix that in the next round.
> > struct sg_table *sgt;
> > enum dma_data_direction dir;
> > struct list_head debugfs_list;
> > diff --git a/drivers/misc/habanalabs/common/memory.c b/drivers/misc/habanalabs/common/memory.c
> > index 5ff4688683fd..327b64479f97 100644
> > --- a/drivers/misc/habanalabs/common/memory.c
> > +++ b/drivers/misc/habanalabs/common/memory.c
> > @@ -1281,45 +1281,41 @@ static int get_user_memory(struct hl_device *hdev, u64 addr, u64 size,
> > return -EFAULT;
> > }
> >
> > - userptr->vec = frame_vector_create(npages);
> > - if (!userptr->vec) {
> > + userptr->pages = kvmalloc_array(npages, sizeof(*userptr->pages),
> > + GFP_KERNEL);
> > + if (!userptr->pages) {
> > dev_err(hdev->dev, "Failed to create frame vector\n");
> > return -ENOMEM;
> > }
> >
> > - rc = get_vaddr_frames(start, npages, FOLL_FORCE | FOLL_WRITE,
> > - userptr->vec);
> > + rc = pin_user_pages_fast(start, npages, FOLL_FORCE | FOLL_WRITE,
> > + userptr->pages);
> >
> > if (rc != npages) {
> > dev_err(hdev->dev,
> > "Failed to map host memory, user ptr probably wrong\n");
> > if (rc < 0)
> > - goto destroy_framevec;
> > + goto destroy_pages;
> > + npages = rc;
> > rc = -EFAULT;
> > - goto put_framevec;
> > - }
> > -
> > - if (frame_vector_to_pages(userptr->vec) < 0) {
> > - dev_err(hdev->dev,
> > - "Failed to translate frame vector to pages\n");
> > - rc = -EFAULT;
> > - goto put_framevec;
> > + goto put_pages;
> > }
> > + userptr->npages = npages;
> >
> > rc = sg_alloc_table_from_pages(userptr->sgt,
> > - frame_vector_pages(userptr->vec),
> > - npages, offset, size, GFP_ATOMIC);
> > + userptr->pages,
> > + npages, offset, size, GFP_ATOMIC);
> I think that because the call to kvmalloc_array() is done with
> GFP_KERNEL, there is no point in using GFP_ATOMIC here.
> And actually, this path only needs to avoid yielding when using a
> special debug mode.
> So I suggest putting here GFP_KERNEL.
Huh, I didn't even notice the GFP_ATOMIC here. This looks indeed
strange and GFP_KERNEL should be perfectly fine in a function that
also calls pin_user_pages (since that one can allocate and do worse
stuff like userspace pagefaults).
But since that GFP_ATOMIC is there already I'll do that in a separate patch.
> In the meanwhile, I'll run this patch (coupled with the next patch) in
> our C/I to make sure there are no regressions.
Excellent. I'll wait with v3 until that's done, just in case you hit a
snag I need to fix.
Cheers, Daniel
> Thanks,
> Oded
>
> > if (rc < 0) {
> > dev_err(hdev->dev, "failed to create SG table from pages\n");
> > - goto put_framevec;
> > + goto put_pages;
> > }
> >
> > return 0;
> >
> > -put_framevec:
> > - put_vaddr_frames(userptr->vec);
> > -destroy_framevec:
> > - frame_vector_destroy(userptr->vec);
> > +put_pages:
> > + unpin_user_pages(userptr->pages, npages);
> > +destroy_pages:
> > + kvfree(userptr->pages);
> > return rc;
> > }
> >
> > @@ -1405,8 +1401,6 @@ int hl_pin_host_memory(struct hl_device *hdev, u64 addr, u64 size,
> > */
> > void hl_unpin_host_memory(struct hl_device *hdev, struct hl_userptr *userptr)
> > {
> > - struct page **pages;
> > -
> > hl_debugfs_remove_userptr(hdev, userptr);
> >
> > if (userptr->dma_mapped)
> > @@ -1414,15 +1408,8 @@ void hl_unpin_host_memory(struct hl_device *hdev, struct hl_userptr *userptr)
> > userptr->sgt->nents,
> > userptr->dir);
> >
> > - pages = frame_vector_pages(userptr->vec);
> > - if (!IS_ERR(pages)) {
> > - int i;
> > -
> > - for (i = 0; i < frame_vector_count(userptr->vec); i++)
> > - set_page_dirty_lock(pages[i]);
> > - }
> > - put_vaddr_frames(userptr->vec);
> > - frame_vector_destroy(userptr->vec);
> > + unpin_user_pages_dirty_lock(userptr->pages, userptr->npages, true);
> > + kvfree(userptr->pages);
> >
> > list_del(&userptr->job_node);
> >
> > --
> > 2.28.0
> >
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
