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| author |   Jason Gunthorpe <jgg@nvidia.com> | 2020-09-04 19:41:44 -0300 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2020-09-09 15:33:17 -0300 |
| commit | 3361c29e9279e682c0e9a7d7461b4e3bbc77830b (patch) | |
| tree | a4c62c20f951a7cb9f009b0716f25d74b5f4fe81 /drivers/infiniband/core/umem.c | |
| parent | RDMA/umem: Prevent small pages from being returned by ib_umem_find_best_pgsz() (diff) | |
| download | linux-dev-3361c29e9279e682c0e9a7d7461b4e3bbc77830b.tar.xz linux-dev-3361c29e9279e682c0e9a7d7461b4e3bbc77830b.zip | |
RDMA/umem: Use simpler logic for ib_umem_find_best_pgsz()
The calculation in rdma_find_pg_bit() is fairly complicated, and the
function is never called anywhere else. Inline a simpler version into
ib_umem_find_best_pgsz()
Link: https://lore.kernel.org/r/3-v2-270386b7e60b+28f4-umem_1_jgg@nvidia.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'drivers/infiniband/core/umem.c')
| -rw-r--r-- | drivers/infiniband/core/umem.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 1d0599997d0f..fb7630e7aac3 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -39,6 +39,7 @@ #include <linux/export.h> #include <linux/slab.h> #include <linux/pagemap.h> +#include <linux/count_zeros.h> #include <rdma/ib_umem_odp.h> #include "uverbs.h" @@ -146,7 +147,6 @@ unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem, unsigned long virt) { struct scatterlist *sg; - unsigned int best_pg_bit; unsigned long va, pgoff; dma_addr_t mask; int i; @@ -186,9 +186,14 @@ unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem, mask |= va; pgoff = 0; } - best_pg_bit = rdma_find_pg_bit(mask, pgsz_bitmap); - return BIT_ULL(best_pg_bit); + /* The mask accumulates 1's in each position where the VA and physical + * address differ, thus the length of trailing 0 is the largest page + * size that can pass the VA through to the physical. + */ + if (mask) + pgsz_bitmap &= GENMASK(count_trailing_zeros(mask), 0); + return rounddown_pow_of_two(pgsz_bitmap); } EXPORT_SYMBOL(ib_umem_find_best_pgsz); |