[PATCH 5.1 055/122] RDMA/mlx5: Use get_zeroed_page() for clock_info

Greg Kroah-Hartman
2019-05-23T19:28:05Z

From: Jason Gunthorpe <jgg@mellanox.com>

commit ddcdc368b1033e19fd3a5f750752e10e28a87826 upstream.

get_zeroed_page() returns a virtual address for the page which is better
than allocating a struct page and doing a permanent kmap on it.

Cc: stable@vger.kernel.org
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/infiniband/hw/mlx5/main.c | 5 ++-
drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c | 30 +++++++-------------
include/linux/mlx5/driver.h | 1
3 files changed, 14 insertions(+), 22 deletions(-)

--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -2070,11 +2070,12 @@ static int mlx5_ib_mmap_clock_info_page(
return -EPERM;
vma->vm_flags &= ~VM_MAYWRITE;

- if (!dev->mdev->clock_info_page)
+ if (!dev->mdev->clock_info)
return -EOPNOTSUPP;

return rdma_user_mmap_page(&context->ibucontext, vma,
- dev->mdev->clock_info_page, PAGE_SIZE);
+ virt_to_page(dev->mdev->clock_info),
+ PAGE_SIZE);
}

static int uar_mmap(struct mlx5_ib_dev *dev, enum mlx5_ib_mmap_cmd cmd,
--- a/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c
@@ -535,23 +535,16 @@ void mlx5_init_clock(struct mlx5_core_de
do_div(ns, NSEC_PER_SEC / HZ);
clock->overflow_period = ns;

- mdev->clock_info_page = alloc_page(GFP_KERNEL);
- if (mdev->clock_info_page) {
- mdev->clock_info = kmap(mdev->clock_info_page);
- if (!mdev->clock_info) {
- __free_page(mdev->clock_info_page);
- mlx5_core_warn(mdev, "failed to map clock page\n");
- } else {
- mdev->clock_info->sign = 0;
- mdev->clock_info->nsec = clock->tc.nsec;
- mdev->clock_info->cycles = clock->tc.cycle_last;
- mdev->clock_info->mask = clock->cycles.mask;
- mdev->clock_info->mult = clock->nominal_c_mult;
- mdev->clock_info->shift = clock->cycles.shift;
- mdev->clock_info->frac = clock->tc.frac;
- mdev->clock_info->overflow_period =
- clock->overflow_period;
- }
+ mdev->clock_info =
+ (struct mlx5_ib_clock_info *)get_zeroed_page(GFP_KERNEL);
+ if (mdev->clock_info) {
+ mdev->clock_info->nsec = clock->tc.nsec;
+ mdev->clock_info->cycles = clock->tc.cycle_last;
+ mdev->clock_info->mask = clock->cycles.mask;
+ mdev->clock_info->mult = clock->nominal_c_mult;
+ mdev->clock_info->shift = clock->cycles.shift;
+ mdev->clock_info->frac = clock->tc.frac;
+ mdev->clock_info->overflow_period = clock->overflow_period;
}

INIT_WORK(&clock->pps_info.out_work, mlx5_pps_out);
@@ -599,8 +592,7 @@ void mlx5_cleanup_clock(struct mlx5_core
cancel_delayed_work_sync(&clock->overflow_work);

if (mdev->clock_info) {
- kunmap(mdev->clock_info_page);
- __free_page(mdev->clock_info_page);
+ free_page((unsigned long)mdev->clock_info);
mdev->clock_info = NULL;
}

--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -681,7 +681,6 @@ struct mlx5_core_dev {
#endif
struct mlx5_clock clock;
struct mlx5_ib_clock_info *clock_info;
- struct page *clock_info_page;
struct mlx5_fw_tracer *tracer;
};