summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJason Gunthorpe <jgg@nvidia.com>2020-09-04 19:41:44 -0300
committerJason Gunthorpe <jgg@nvidia.com>2020-09-09 15:33:17 -0300
commit3361c29e9279e682c0e9a7d7461b4e3bbc77830b (patch)
treea4c62c20f951a7cb9f009b0716f25d74b5f4fe81
parent10c75ccb54e4fe548cb16d7ed426d7d709e6ae76 (diff)
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>
-rw-r--r--drivers/infiniband/core/umem.c11
-rw-r--r--include/rdma/ib_verbs.h24
2 files changed, 8 insertions, 27 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);
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 29a36ec662b5..97658d706aa1 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -3336,30 +3336,6 @@ static inline bool rdma_cap_read_inv(struct ib_device *dev, u32 port_num)
}
/**
- * rdma_find_pg_bit - Find page bit given address and HW supported page sizes
- *
- * @addr: address
- * @pgsz_bitmap: bitmap of HW supported page sizes
- */
-static inline unsigned int rdma_find_pg_bit(unsigned long addr,
- unsigned long pgsz_bitmap)
-{
- unsigned long align;
- unsigned long pgsz;
-
- align = addr & -addr;
-
- /* Find page bit such that addr is aligned to the highest supported
- * HW page size
- */
- pgsz = pgsz_bitmap & ~(-align << 1);
- if (!pgsz)
- return __ffs(pgsz_bitmap);
-
- return __fls(pgsz);
-}
-
-/**
* rdma_core_cap_opa_port - Return whether the RDMA Port is OPA or not.
* @device: Device
* @port_num: 1 based Port number