Re: [PATCH 07/19] infiniband: set FOLL_PIN, FOLL_LONGTERM via pin_longterm_pages*()

From: Ira Weiny
Date: Thu Oct 31 2019 - 19:25:52 EST

On Wed, Oct 30, 2019 at 03:49:18PM -0700, John Hubbard wrote:
> Convert infiniband to use the new wrapper calls, and stop
> explicitly setting FOLL_LONGTERM at the call sites.
>
> The new pin_longterm_*() calls replace get_user_pages*()
> calls, and set both FOLL_LONGTERM and a new FOLL_PIN
> flag. The FOLL_PIN flag requires that the caller must
> return the pages via put_user_page*() calls, but
> infiniband was already doing that as part of an earlier
> commit.
>

NOTE: I'm not 100% convinced that mixing the flags and new calls like this is
good. I think we are going to need a lot more documentation on which flags are
"user" accessible vs not...

Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>

> Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
> ---
> drivers/infiniband/core/umem.c | 5 ++---
> drivers/infiniband/core/umem_odp.c | 10 +++++-----
> drivers/infiniband/hw/hfi1/user_pages.c | 4 ++--
> drivers/infiniband/hw/mthca/mthca_memfree.c | 3 +--
> drivers/infiniband/hw/qib/qib_user_pages.c | 8 ++++----
> drivers/infiniband/hw/qib/qib_user_sdma.c | 2 +-
> drivers/infiniband/hw/usnic/usnic_uiom.c | 9 ++++-----
> drivers/infiniband/sw/siw/siw_mem.c | 5 ++---
> 8 files changed, 21 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
> index 24244a2f68cc..c5a78d3e674b 100644
> --- a/drivers/infiniband/core/umem.c
> +++ b/drivers/infiniband/core/umem.c
> @@ -272,11 +272,10 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr,
>
> while (npages) {
> down_read(&mm->mmap_sem);
> - ret = get_user_pages(cur_base,
> + ret = pin_longterm_pages(cur_base,
> min_t(unsigned long, npages,
> PAGE_SIZE / sizeof (struct page *)),
> - gup_flags | FOLL_LONGTERM,
> - page_list, NULL);
> + gup_flags, page_list, NULL);
> if (ret < 0) {
> up_read(&mm->mmap_sem);
> goto umem_release;
> diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c
> index 163ff7ba92b7..a38b67b83db5 100644
> --- a/drivers/infiniband/core/umem_odp.c
> +++ b/drivers/infiniband/core/umem_odp.c
> @@ -534,7 +534,7 @@ static int ib_umem_odp_map_dma_single_page(
> } else if (umem_odp->page_list[page_index] == page) {
> umem_odp->dma_list[page_index] |= access_mask;
> } else {
> - pr_err("error: got different pages in IB device and from get_user_pages. IB device page: %p, gup page: %p\n",
> + pr_err("error: got different pages in IB device and from pin_longterm_pages. IB device page: %p, gup page: %p\n",
> umem_odp->page_list[page_index], page);
> /* Better remove the mapping now, to prevent any further
> * damage. */
> @@ -639,11 +639,11 @@ int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 user_virt,
> /*
> * Note: this might result in redundent page getting. We can
> * avoid this by checking dma_list to be 0 before calling
> - * get_user_pages. However, this make the code much more
> - * complex (and doesn't gain us much performance in most use
> - * cases).
> + * pin_longterm_pages. However, this makes the code much
> + * more complex (and doesn't gain us much performance in most
> + * use cases).
> */
> - npages = get_user_pages_remote(owning_process, owning_mm,
> + npages = pin_longterm_pages_remote(owning_process, owning_mm,
> user_virt, gup_num_pages,
> flags, local_page_list, NULL, NULL);
> up_read(&owning_mm->mmap_sem);
> diff --git a/drivers/infiniband/hw/hfi1/user_pages.c b/drivers/infiniband/hw/hfi1/user_pages.c
> index 469acb961fbd..9b55b0a73e29 100644
> --- a/drivers/infiniband/hw/hfi1/user_pages.c
> +++ b/drivers/infiniband/hw/hfi1/user_pages.c
> @@ -104,9 +104,9 @@ int hfi1_acquire_user_pages(struct mm_struct *mm, unsigned long vaddr, size_t np
> bool writable, struct page **pages)
> {
> int ret;
> - unsigned int gup_flags = FOLL_LONGTERM | (writable ? FOLL_WRITE : 0);
> + unsigned int gup_flags = (writable ? FOLL_WRITE : 0);
>
> - ret = get_user_pages_fast(vaddr, npages, gup_flags, pages);
> + ret = pin_longterm_pages_fast(vaddr, npages, gup_flags, pages);
> if (ret < 0)
> return ret;
>
> diff --git a/drivers/infiniband/hw/mthca/mthca_memfree.c b/drivers/infiniband/hw/mthca/mthca_memfree.c
> index edccfd6e178f..beec7e4b8a96 100644
> --- a/drivers/infiniband/hw/mthca/mthca_memfree.c
> +++ b/drivers/infiniband/hw/mthca/mthca_memfree.c
> @@ -472,8 +472,7 @@ int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
> goto out;
> }
>
> - ret = get_user_pages_fast(uaddr & PAGE_MASK, 1,
> - FOLL_WRITE | FOLL_LONGTERM, pages);
> + ret = pin_longterm_pages_fast(uaddr & PAGE_MASK, 1, FOLL_WRITE, pages);
> if (ret < 0)
> goto out;
>
> diff --git a/drivers/infiniband/hw/qib/qib_user_pages.c b/drivers/infiniband/hw/qib/qib_user_pages.c
> index 6bf764e41891..684a14e14d9b 100644
> --- a/drivers/infiniband/hw/qib/qib_user_pages.c
> +++ b/drivers/infiniband/hw/qib/qib_user_pages.c
> @@ -108,10 +108,10 @@ int qib_get_user_pages(unsigned long start_page, size_t num_pages,
>
> down_read(&current->mm->mmap_sem);
> for (got = 0; got < num_pages; got += ret) {
> - ret = get_user_pages(start_page + got * PAGE_SIZE,
> - num_pages - got,
> - FOLL_LONGTERM | FOLL_WRITE | FOLL_FORCE,
> - p + got, NULL);
> + ret = pin_longterm_pages(start_page + got * PAGE_SIZE,
> + num_pages - got,
> + FOLL_WRITE | FOLL_FORCE,
> + p + got, NULL);
> if (ret < 0) {
> up_read(&current->mm->mmap_sem);
> goto bail_release;
> diff --git a/drivers/infiniband/hw/qib/qib_user_sdma.c b/drivers/infiniband/hw/qib/qib_user_sdma.c
> index 05190edc2611..fd86a9d19370 100644
> --- a/drivers/infiniband/hw/qib/qib_user_sdma.c
> +++ b/drivers/infiniband/hw/qib/qib_user_sdma.c
> @@ -670,7 +670,7 @@ static int qib_user_sdma_pin_pages(const struct qib_devdata *dd,
> else
> j = npages;
>
> - ret = get_user_pages_fast(addr, j, FOLL_LONGTERM, pages);
> + ret = pin_longterm_pages_fast(addr, j, 0, pages);
> if (ret != j) {
> i = 0;
> j = ret;
> diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c
> index 62e6ffa9ad78..6b90ca1c3771 100644
> --- a/drivers/infiniband/hw/usnic/usnic_uiom.c
> +++ b/drivers/infiniband/hw/usnic/usnic_uiom.c
> @@ -141,11 +141,10 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable,
> ret = 0;
>
> while (npages) {
> - ret = get_user_pages(cur_base,
> - min_t(unsigned long, npages,
> - PAGE_SIZE / sizeof(struct page *)),
> - gup_flags | FOLL_LONGTERM,
> - page_list, NULL);
> + ret = pin_longterm_pages(cur_base,
> + min_t(unsigned long, npages,
> + PAGE_SIZE / sizeof(struct page *)),
> + gup_flags, page_list, NULL);
>
> if (ret < 0)
> goto out;
> diff --git a/drivers/infiniband/sw/siw/siw_mem.c b/drivers/infiniband/sw/siw/siw_mem.c
> index e99983f07663..20e663d7ada8 100644
> --- a/drivers/infiniband/sw/siw/siw_mem.c
> +++ b/drivers/infiniband/sw/siw/siw_mem.c
> @@ -426,9 +426,8 @@ struct siw_umem *siw_umem_get(u64 start, u64 len, bool writable)
> while (nents) {
> struct page **plist = &umem->page_chunk[i].plist[got];
>
> - rv = get_user_pages(first_page_va, nents,
> - foll_flags | FOLL_LONGTERM,
> - plist, NULL);
> + rv = pin_longterm_pages(first_page_va, nents,
> + foll_flags, plist, NULL);
> if (rv < 0)
> goto out_sem_up;
>
> --
> 2.23.0
>