From: Jason Gunthorpe <jgg@xxxxxxxxxx>
SRQ uses a quantized and scaled page_offset, which is another variation of
ib_umem_find_best_pgsz(). Add mlx5_umem_find_best_quantized_pgoff() to
perform this calculation for each mailbox. A macro shows how the
calculation is directly connected to the mailbox format.
This new routine replaces the limited mlx5_ib_cont_pages() and
mlx5_ib_get_buf_offset() pairing which would reject valid configurations
rather than adjust the page_size to make it work.
In turn this is much more aggressive about choosing large page sizes for
these objects and when THP is enabled it will now often find a single page
solution.
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
---
drivers/infiniband/hw/mlx5/mem.c | 45 ++++++++++++++++++++++++++++
drivers/infiniband/hw/mlx5/mlx5_ib.h | 31 +++++++++++++++++++
drivers/infiniband/hw/mlx5/srq.c | 20 ++++++-------
include/rdma/ib_umem.h | 42 ++++++++++++++++++++++++++
4 files changed, 128 insertions(+), 10 deletions(-)
diff --git a/drivers/infiniband/hw/mlx5/mem.c b/drivers/infiniband/hw/mlx5/mem.c
index 92e7621ec858..fd9778113d26 100644
--- a/drivers/infiniband/hw/mlx5/mem.c
+++ b/drivers/infiniband/hw/mlx5/mem.c
@@ -107,6 +107,51 @@ void mlx5_ib_populate_pas(struct ib_umem *umem, size_t page_size, __be64 *pas,
}
}
+/*
+ * Compute the page shift and page_offset for mailboxes that use a quantized
+ * page_offset. The granulatity of the page offset scales according to page
+ * size.
+ */
+unsigned long __mlx5_umem_find_best_quantized_pgoff(
+ struct ib_umem *umem, unsigned long pgsz_bitmap,
+ unsigned int page_offset_bits, u64 pgoff_bitmask, unsigned int scale,
+ unsigned int *page_offset_quantized)
+{
+ const u64 page_offset_mask = (1 << page_offset_bits) - 1;
+ unsigned long page_size;
+ u64 page_offset;
+
+ page_size = ib_umem_find_best_pgoff(umem, pgsz_bitmap, pgoff_bitmask);
+ if (!page_size)
+ return 0;
+
+ /*
+ * page size is the largest possible page size.
+ *
+ * Reduce the page_size, and thus the page_offset and quanta, until the
+ * page_offset fits into the mailbox field. Once page_size < scale this
+ * loop is guaranteed to terminate.
+ */
+ page_offset = ib_umem_dma_offset(umem, page_size);
+ while (page_offset & ~(u64)(page_offset_mask * (page_size / scale))) {
+ page_size /= 2;
+ page_offset = ib_umem_dma_offset(umem, page_size);
+ }
+
+ /*
+ * The address is not aligned, or otherwise cannot be represented by the
+ * page_offset.
+ */
+ if (!(pgsz_bitmap & page_size))
+ return 0;
+
+ *page_offset_quantized =
+ (unsigned long)page_offset / (page_size / scale);
+ if (WARN_ON(*page_offset_quantized > page_offset_mask))
+ return 0;
+ return page_size;
+}
+
int mlx5_ib_get_buf_offset(u64 addr, int page_shift, u32 *offset)
{
u64 page_size;
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index bb44080170be..2f08a5b4a438 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -69,6 +69,37 @@ __mlx5_log_page_size_to_bitmap(unsigned int log_pgsz_bits,
pgsz_shift), \
iova)
+static __always_inline unsigned long
+__mlx5_page_offset_to_bitmask(unsigned int page_offset_bits,
+ unsigned int offset_shift)
+{
+ unsigned int largest_offset_shift =
+ min_t(unsigned long, page_offset_bits - 1 + offset_shift,
+ BITS_PER_LONG - 1);
+
+ return GENMASK(largest_offset_shift, offset_shift);
+}
+
+/*
+ * QP/CQ/WQ/etc type commands take a page offset that satisifies:
+ * page_offset_quantized * (page_size/scale) = page_offset
+ * Which restricts allowed page sizes to ones that satisify the above.
+ */
+unsigned long __mlx5_umem_find_best_quantized_pgoff(
+ struct ib_umem *umem, unsigned long pgsz_bitmap,
+ unsigned int page_offset_bits, u64 pgoff_bitmask, unsigned int scale,
+ unsigned int *page_offset_quantized);
+#define mlx5_umem_find_best_quantized_pgoff(umem, typ, log_pgsz_fld, \
+ pgsz_shift, page_offset_fld, \
+ scale, page_offset_quantized) \
+ __mlx5_umem_find_best_quantized_pgoff( \
+ umem, \
+ __mlx5_log_page_size_to_bitmap( \
+ __mlx5_bit_sz(typ, log_pgsz_fld), pgsz_shift), \
+ __mlx5_bit_sz(typ, page_offset_fld), \
+ GENMASK(31, order_base_2(scale)), scale, \
+ page_offset_quantized)
+
enum {
MLX5_IB_MMAP_OFFSET_START = 9,
MLX5_IB_MMAP_OFFSET_END = 255,
diff --git a/drivers/infiniband/hw/mlx5/srq.c b/drivers/infiniband/hw/mlx5/srq.c
index cb5ad045da9a..7dfdc9e54866 100644
--- a/drivers/infiniband/hw/mlx5/srq.c
+++ b/drivers/infiniband/hw/mlx5/srq.c
@@ -51,8 +51,8 @@ static int create_srq_user(struct ib_pd *pd, struct mlx5_ib_srq *srq,
udata, struct mlx5_ib_ucontext, ibucontext);
size_t ucmdlen;
int err;
- int page_shift;
- u32 offset;
+ unsigned int page_offset_quantized;
+ unsigned int page_size;
u32 uidx = MLX5_IB_DEFAULT_UIDX;
ucmdlen = min(udata->inlen, sizeof(ucmd));
@@ -85,22 +85,22 @@ static int create_srq_user(struct ib_pd *pd, struct mlx5_ib_srq *srq,
return err;
}
- mlx5_ib_cont_pages(srq->umem, ucmd.buf_addr, 0, &page_shift);
- err = mlx5_ib_get_buf_offset(ucmd.buf_addr, page_shift,
- &offset);
- if (err) {
+ page_size = mlx5_umem_find_best_quantized_pgoff(
+ srq->umem, srqc, log_page_size, MLX5_ADAPTER_PAGE_SHIFT,
+ page_offset, 64, &page_offset_quantized);
+ if (!page_size) {
mlx5_ib_warn(dev, "bad offset\n");
goto err_umem;
}
- in->pas = kvcalloc(ib_umem_num_dma_blocks(srq->umem, 1UL << page_shift),
+ in->pas = kvcalloc(ib_umem_num_dma_blocks(srq->umem, page_size),
sizeof(*in->pas), GFP_KERNEL);
if (!in->pas) {
err = -ENOMEM;
goto err_umem;
}
- mlx5_ib_populate_pas(srq->umem, 1UL << page_shift, in->pas, 0);
+ mlx5_ib_populate_pas(srq->umem, page_size, in->pas, 0);
err = mlx5_ib_db_map_user(ucontext, udata, ucmd.db_addr, &srq->db);
if (err) {
@@ -108,8 +108,8 @@ static int create_srq_user(struct ib_pd *pd, struct mlx5_ib_srq *srq,
goto err_in;
}
- in->log_page_size = page_shift - MLX5_ADAPTER_PAGE_SHIFT;
- in->page_offset = offset;
+ in->log_page_size = order_base_2(page_size) - MLX5_ADAPTER_PAGE_SHIFT;
+ in->page_offset = page_offset_quantized;
in->uid = (in->type != IB_SRQT_XRC) ? to_mpd(pd)->uid : 0;
if (MLX5_CAP_GEN(dev->mdev, cqe_version) == MLX5_CQE_VERSION_V1 &&
in->type != IB_SRQT_BASIC)
diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h
index 70597508c765..7752211c9638 100644
--- a/include/rdma/ib_umem.h
+++ b/include/rdma/ib_umem.h
@@ -34,6 +34,13 @@ static inline int ib_umem_offset(struct ib_umem *umem)
return umem->address & ~PAGE_MASK;
}
+static inline unsigned long ib_umem_dma_offset(struct ib_umem *umem,
+ unsigned long pgsz)
+{
+ return (sg_dma_address(umem->sg_head.sgl) + ib_umem_offset(umem)) &
+ (pgsz - 1);
+}
+
static inline size_t ib_umem_num_dma_blocks(struct ib_umem *umem,
unsigned long pgsz)
{
@@ -79,6 +86,35 @@ int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
unsigned long pgsz_bitmap,
unsigned long virt);
+/**
+ * ib_umem_find_best_pgoff - Find best HW page size
+ *
+ * @umem: umem struct
+ * @pgsz_bitmap bitmap of HW supported page sizes
+ * @pgoff_bitmask: Mask of bits that can be represented with an offset
+ *
+ * This is very similar to ib_umem_find_best_pgsz() except instead of accepting
+ * an IOVA it accepts a bitmask specifying what address bits can be represented
+ * with a page offset.
+ *
+ * For instance if the HW has multiple page sizes, requires 64 byte alignemnt,
+ * and can support aligned offsets up to 4032 then pgoff_bitmask would be
+ * "111111000000".
+ *
+ * If the pgoff_bitmask requires either alignment in the low bit or an
+ * unavailable page size for the high bits, this function returns 0.
+ */
+static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
+ unsigned long pgsz_bitmap,
+ u64 pgoff_bitmask)
+{
+ struct scatterlist *sg = umem->sg_head.sgl;
+ dma_addr_t dma_addr;
+
+ dma_addr = sg_dma_address(sg) + (umem->address & ~PAGE_MASK);
+ return ib_umem_find_best_pgsz(umem, pgsz_bitmap,
+ dma_addr & pgoff_bitmask);
+}
#else /* CONFIG_INFINIBAND_USER_MEM */
@@ -101,6 +137,12 @@ static inline unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
{
return 0;
}
+static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
+ unsigned long pgsz_bitmap,
+ u64 pgoff_bitmask)
+{
+ return 0;
+}
#endif /* CONFIG_INFINIBAND_USER_MEM */
--
2.28.0
