* [PATCH mlx5-next] net/mlx5: Consolidate UAR index to PFN helpers
@ 2026-05-19 15:08 Leon Romanovsky
2026-05-19 15:32 ` Jason Gunthorpe
0 siblings, 1 reply; 2+ messages in thread
From: Leon Romanovsky @ 2026-05-19 15:08 UTC (permalink / raw)
To: Leon Romanovsky, Jason Gunthorpe, Saeed Mahameed, Tariq Toukan,
Mark Bloch, Andrew Lunn, David S. Miller, Eric Dumazet,
Jakub Kicinski, Paolo Abeni
Cc: linux-rdma, linux-kernel, netdev
From: Leon Romanovsky <leonro@nvidia.com>
mlx5_core's uar2pfn() and mlx5_ib's uar_index2pfn() compute the same
value via slightly different idioms. Given:
MLX5_ADAPTER_PAGE_SHIFT = 12
MLX5_UARS_IN_PAGE = PAGE_SIZE / MLX5_ADAPTER_PAGE_SIZE
= 1 << (PAGE_SHIFT - 12)
when uar_4k is set, uar2pfn()'s "index >> (PAGE_SHIFT - 12)" reduces to
"index / MLX5_UARS_IN_PAGE", which is exactly what uar_index2pfn() does.
When uar_4k is clear, both fall through to the identity case. The same
arithmetic is also open-coded a third time in uar_index2paddress(), which
just multiplies the result by PAGE_SIZE.
The duplication is historical: uar_index2pfn() landed with the original
mlx5_ib driver in 2013 (e126ba97dba9), uar2pfn() was added in 2017
(a6d51b68611e) when the bfreg allocator moved into mlx5_core, and no
shared header ever exposed the helper. The two were last touched in
parallel by aa8106f137b9 ("net/mlx5: Add explicit bar address field"),
confirming they are meant to behave identically.
Replace all three local copies with two static inlines in
include/linux/mlx5/driver.h returning phys_addr_t, which is the
appropriate type for a value that subsequently feeds ioremap*() and
rdma_user_mmap_io(). No functional change.
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
mlx5_core's uar2pfn() and mlx5_ib's uar_index2pfn() compute the same
value via slightly different idioms. Let's consolidate them.
---
drivers/infiniband/hw/mlx5/main.c | 25 ++-----------------------
drivers/net/ethernet/mellanox/mlx5/core/uar.c | 14 +-------------
include/linux/mlx5/driver.h | 16 ++++++++++++++++
3 files changed, 19 insertions(+), 36 deletions(-)
diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index 428811fa805b..e61db29bc166 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -2373,27 +2373,6 @@ static void mlx5_ib_dealloc_ucontext(struct ib_ucontext *ibcontext)
}
}
-static phys_addr_t uar_index2pfn(struct mlx5_ib_dev *dev,
- int uar_idx)
-{
- int fw_uars_per_page;
-
- fw_uars_per_page = MLX5_CAP_GEN(dev->mdev, uar_4k) ? MLX5_UARS_IN_PAGE : 1;
-
- return (dev->mdev->bar_addr >> PAGE_SHIFT) + uar_idx / fw_uars_per_page;
-}
-
-static u64 uar_index2paddress(struct mlx5_ib_dev *dev,
- int uar_idx)
-{
- unsigned int fw_uars_per_page;
-
- fw_uars_per_page = MLX5_CAP_GEN(dev->mdev, uar_4k) ?
- MLX5_UARS_IN_PAGE : 1;
-
- return (dev->mdev->bar_addr + (uar_idx / fw_uars_per_page) * PAGE_SIZE);
-}
-
static int get_command(unsigned long offset)
{
return (offset >> MLX5_IB_MMAP_CMD_SHIFT) & MLX5_IB_MMAP_CMD_MASK;
@@ -2643,7 +2622,7 @@ static int uar_mmap(struct mlx5_ib_dev *dev, enum mlx5_ib_mmap_cmd cmd,
uar_index = bfregi->sys_pages[idx];
}
- pfn = uar_index2pfn(dev, uar_index);
+ pfn = mlx5_uar_index_to_pfn(dev->mdev, uar_index);
mlx5_ib_dbg(dev, "uar idx 0x%lx, pfn %pa\n", idx, &pfn);
err = rdma_user_mmap_io(&context->ibucontext, vma, pfn, PAGE_SIZE,
@@ -4327,7 +4306,7 @@ alloc_uar_entry(struct mlx5_ib_ucontext *c,
goto end;
entry->page_idx = uar_index;
- entry->address = uar_index2paddress(dev, uar_index);
+ entry->address = mlx5_uar_index_to_paddr(dev->mdev, uar_index);
if (alloc_type == MLX5_IB_UAPI_UAR_ALLOC_TYPE_BF)
entry->mmap_flag = MLX5_IB_MMAP_TYPE_UAR_WC;
else
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/uar.c b/drivers/net/ethernet/mellanox/mlx5/core/uar.c
index 1513112ecec8..a85d8fed1546 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/uar.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/uar.c
@@ -66,18 +66,6 @@ static int uars_per_sys_page(struct mlx5_core_dev *mdev)
return 1;
}
-static u64 uar2pfn(struct mlx5_core_dev *mdev, u32 index)
-{
- u32 system_page_index;
-
- if (MLX5_CAP_GEN(mdev, uar_4k))
- system_page_index = index >> (PAGE_SHIFT - MLX5_ADAPTER_PAGE_SHIFT);
- else
- system_page_index = index;
-
- return (mdev->bar_addr >> PAGE_SHIFT) + system_page_index;
-}
-
static void up_rel_func(struct kref *kref)
{
struct mlx5_uars_page *up = container_of(kref, struct mlx5_uars_page, ref_count);
@@ -132,7 +120,7 @@ static struct mlx5_uars_page *alloc_uars_page(struct mlx5_core_dev *mdev,
goto error1;
}
- pfn = uar2pfn(mdev, up->index);
+ pfn = mlx5_uar_index_to_pfn(mdev, up->index);
if (map_wc) {
up->map = ioremap_wc(pfn << PAGE_SHIFT, PAGE_SIZE);
if (!up->map) {
diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
index 04b96c5abb57..10eec559fd58 100644
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -908,6 +908,22 @@ static inline u32 wq_get_byte_sz(u8 log_sz, u8 log_stride)
return ((u32)1 << log_sz) << log_stride;
}
+static inline phys_addr_t mlx5_uar_index_to_pfn(struct mlx5_core_dev *mdev,
+ u32 uar_idx)
+{
+ u32 fw_uars_per_page = MLX5_CAP_GEN(mdev, uar_4k) ? MLX5_UARS_IN_PAGE : 1;
+
+ return (mdev->bar_addr >> PAGE_SHIFT) + uar_idx / fw_uars_per_page;
+}
+
+static inline phys_addr_t mlx5_uar_index_to_paddr(struct mlx5_core_dev *mdev,
+ u32 uar_idx)
+{
+ u32 fw_uars_per_page = MLX5_CAP_GEN(mdev, uar_4k) ? MLX5_UARS_IN_PAGE : 1;
+
+ return mdev->bar_addr + (uar_idx / fw_uars_per_page) * PAGE_SIZE;
+}
+
static inline void mlx5_init_fbc_offset(struct mlx5_buf_list *frags,
u8 log_stride, u8 log_sz,
u16 strides_offset,
---
base-commit: 67464f388d52ec172be62c99fc43697437ffa384
change-id: 20260511-mlx5-uar-index-107c8052c7d6
Best regards,
--
Leon Romanovsky <leonro@nvidia.com>
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH mlx5-next] net/mlx5: Consolidate UAR index to PFN helpers
2026-05-19 15:08 [PATCH mlx5-next] net/mlx5: Consolidate UAR index to PFN helpers Leon Romanovsky
@ 2026-05-19 15:32 ` Jason Gunthorpe
0 siblings, 0 replies; 2+ messages in thread
From: Jason Gunthorpe @ 2026-05-19 15:32 UTC (permalink / raw)
To: Leon Romanovsky
Cc: Saeed Mahameed, Tariq Toukan, Mark Bloch, Andrew Lunn,
David S. Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni,
linux-rdma, linux-kernel, netdev
On Tue, May 19, 2026 at 06:08:18PM +0300, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@nvidia.com>
>
> mlx5_core's uar2pfn() and mlx5_ib's uar_index2pfn() compute the same
> value via slightly different idioms. Given:
>
> MLX5_ADAPTER_PAGE_SHIFT = 12
> MLX5_UARS_IN_PAGE = PAGE_SIZE / MLX5_ADAPTER_PAGE_SIZE
> = 1 << (PAGE_SHIFT - 12)
>
> when uar_4k is set, uar2pfn()'s "index >> (PAGE_SHIFT - 12)" reduces to
> "index / MLX5_UARS_IN_PAGE", which is exactly what uar_index2pfn() does.
> When uar_4k is clear, both fall through to the identity case. The same
> arithmetic is also open-coded a third time in uar_index2paddress(), which
> just multiplies the result by PAGE_SIZE.
>
> The duplication is historical: uar_index2pfn() landed with the original
> mlx5_ib driver in 2013 (e126ba97dba9), uar2pfn() was added in 2017
> (a6d51b68611e) when the bfreg allocator moved into mlx5_core, and no
> shared header ever exposed the helper. The two were last touched in
> parallel by aa8106f137b9 ("net/mlx5: Add explicit bar address field"),
> confirming they are meant to behave identically.
>
> Replace all three local copies with two static inlines in
> include/linux/mlx5/driver.h returning phys_addr_t, which is the
> appropriate type for a value that subsequently feeds ioremap*() and
> rdma_user_mmap_io(). No functional change.
>
> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
> ---
> mlx5_core's uar2pfn() and mlx5_ib's uar_index2pfn() compute the same
> value via slightly different idioms. Let's consolidate them.
> ---
> drivers/infiniband/hw/mlx5/main.c | 25 ++-----------------------
> drivers/net/ethernet/mellanox/mlx5/core/uar.c | 14 +-------------
> include/linux/mlx5/driver.h | 16 ++++++++++++++++
> 3 files changed, 19 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
> index 428811fa805b..e61db29bc166 100644
> --- a/drivers/infiniband/hw/mlx5/main.c
> +++ b/drivers/infiniband/hw/mlx5/main.c
> @@ -2373,27 +2373,6 @@ static void mlx5_ib_dealloc_ucontext(struct ib_ucontext *ibcontext)
> }
> }
>
> -static phys_addr_t uar_index2pfn(struct mlx5_ib_dev *dev,
> - int uar_idx)
> -{
> - int fw_uars_per_page;
> -
> - fw_uars_per_page = MLX5_CAP_GEN(dev->mdev, uar_4k) ? MLX5_UARS_IN_PAGE : 1;
> -
> - return (dev->mdev->bar_addr >> PAGE_SHIFT) + uar_idx / fw_uars_per_page;
> -}
> -
> -static u64 uar_index2paddress(struct mlx5_ib_dev *dev,
> - int uar_idx)
> -{
> - unsigned int fw_uars_per_page;
> -
> - fw_uars_per_page = MLX5_CAP_GEN(dev->mdev, uar_4k) ?
> - MLX5_UARS_IN_PAGE : 1;
> -
> - return (dev->mdev->bar_addr + (uar_idx / fw_uars_per_page) * PAGE_SIZE);
> -}
> -
> static int get_command(unsigned long offset)
> {
> return (offset >> MLX5_IB_MMAP_CMD_SHIFT) & MLX5_IB_MMAP_CMD_MASK;
> @@ -2643,7 +2622,7 @@ static int uar_mmap(struct mlx5_ib_dev *dev, enum mlx5_ib_mmap_cmd cmd,
> uar_index = bfregi->sys_pages[idx];
> }
>
> - pfn = uar_index2pfn(dev, uar_index);
> + pfn = mlx5_uar_index_to_pfn(dev->mdev, uar_index);
> mlx5_ib_dbg(dev, "uar idx 0x%lx, pfn %pa\n", idx, &pfn);
>
> err = rdma_user_mmap_io(&context->ibucontext, vma, pfn, PAGE_SIZE,
> @@ -4327,7 +4306,7 @@ alloc_uar_entry(struct mlx5_ib_ucontext *c,
> goto end;
>
> entry->page_idx = uar_index;
> - entry->address = uar_index2paddress(dev, uar_index);
> + entry->address = mlx5_uar_index_to_paddr(dev->mdev, uar_index);
> if (alloc_type == MLX5_IB_UAPI_UAR_ALLOC_TYPE_BF)
> entry->mmap_flag = MLX5_IB_MMAP_TYPE_UAR_WC;
> else
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/uar.c b/drivers/net/ethernet/mellanox/mlx5/core/uar.c
> index 1513112ecec8..a85d8fed1546 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/uar.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/uar.c
> @@ -66,18 +66,6 @@ static int uars_per_sys_page(struct mlx5_core_dev *mdev)
> return 1;
> }
>
> -static u64 uar2pfn(struct mlx5_core_dev *mdev, u32 index)
> -{
> - u32 system_page_index;
> -
> - if (MLX5_CAP_GEN(mdev, uar_4k))
> - system_page_index = index >> (PAGE_SHIFT - MLX5_ADAPTER_PAGE_SHIFT);
> - else
> - system_page_index = index;
> -
> - return (mdev->bar_addr >> PAGE_SHIFT) + system_page_index;
> -}
> -
> static void up_rel_func(struct kref *kref)
> {
> struct mlx5_uars_page *up = container_of(kref, struct mlx5_uars_page, ref_count);
> @@ -132,7 +120,7 @@ static struct mlx5_uars_page *alloc_uars_page(struct mlx5_core_dev *mdev,
> goto error1;
> }
>
> - pfn = uar2pfn(mdev, up->index);
> + pfn = mlx5_uar_index_to_pfn(mdev, up->index);
> if (map_wc) {
> up->map = ioremap_wc(pfn << PAGE_SHIFT, PAGE_SIZE);
The only places using PFN here immediately shift it, this should be
using mlx5_uar_index_to_paddr()
> +static inline phys_addr_t mlx5_uar_index_to_pfn(struct mlx5_core_dev *mdev,
> + u32 uar_idx)
> +{
> + u32 fw_uars_per_page = MLX5_CAP_GEN(mdev, uar_4k) ? MLX5_UARS_IN_PAGE : 1;
> +
> + return (mdev->bar_addr >> PAGE_SHIFT) + uar_idx / fw_uars_per_page;
> +}
> +
> +static inline phys_addr_t mlx5_uar_index_to_paddr(struct mlx5_core_dev *mdev,
> + u32 uar_idx)
> +{
> + u32 fw_uars_per_page = MLX5_CAP_GEN(mdev, uar_4k) ? MLX5_UARS_IN_PAGE : 1;
> +
> + return mdev->bar_addr + (uar_idx / fw_uars_per_page) * PAGE_SIZE;
> +}
Then there is only one caller of the pfn version in uar_mmap which can
just be written using phys and open code the >> PAGE_SHIFT
No reason to duplicate this
Jason
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