RDMA/mlx5: Store the number of in_use cache mkeys instead of total_mrs

total_mrs is used only to calculate the number of mkeys currently in
use. To simplify things, replace it with a new member called "in_use" and
directly store the number of mkeys currently in use.

Link: https://lore.kernel.org/r/20220726071911.122765-4-michaelgur@nvidia.com
Signed-off-by: Aharon Landau <aharonl@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index e0eb666..da9202f 100644 (file)
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -755,12 +755,10 @@ struct mlx5_cache_ent {
        u8 fill_to_high_water:1;
 
        /*
-        * - total_mrs is stored mkeys plus all in use MRs that could be
-        *   returned to the cache.
         * - limit is the low water mark for stored mkeys, 2* limit is the
         *   upper water mark.
         */
-       u32 total_mrs;
+       u32 in_use;
        u32 limit;
 
        /* Statistics */

diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index cbb8882..26bfdbb 100644 (file)
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -268,7 +268,6 @@ static void create_mkey_callback(int status, struct mlx5_async_work *context)
 
        xa_lock_irqsave(&ent->mkeys, flags);
        push_to_reserved(ent, mr);
-       ent->total_mrs++;
        /* If we are doing fill_to_high_water then keep going. */
        queue_adjust_cache_locked(ent);
        xa_unlock_irqrestore(&ent->mkeys, flags);
@@ -391,9 +390,6 @@ static struct mlx5_ib_mr *create_cache_mr(struct mlx5_cache_ent *ent)
        init_waitqueue_head(&mr->mmkey.wait);
        mr->mmkey.type = MLX5_MKEY_MR;
        WRITE_ONCE(ent->dev->cache.last_add, jiffies);
-       xa_lock_irq(&ent->mkeys);
-       ent->total_mrs++;
-       xa_unlock_irq(&ent->mkeys);
        kfree(in);
        return mr;
 free_mr:
@@ -411,7 +407,6 @@ static void remove_cache_mr_locked(struct mlx5_cache_ent *ent)
        if (!ent->stored)
                return;
        mr = pop_stored_mkey(ent);
-       ent->total_mrs--;
        xa_unlock_irq(&ent->mkeys);
        mlx5_core_destroy_mkey(ent->dev->mdev, mr->mmkey.key);
        kfree(mr);
@@ -467,11 +462,11 @@ static ssize_t size_write(struct file *filp, const char __user *buf,
         * mkeys.
         */
        xa_lock_irq(&ent->mkeys);
-       if (target < ent->total_mrs - ent->stored) {
+       if (target < ent->in_use) {
                err = -EINVAL;
                goto err_unlock;
        }
-       target = target - (ent->total_mrs - ent->stored);
+       target = target - ent->in_use;
        if (target < ent->limit || target > ent->limit*2) {
                err = -EINVAL;
                goto err_unlock;
@@ -495,7 +490,7 @@ static ssize_t size_read(struct file *filp, char __user *buf, size_t count,
        char lbuf[20];
        int err;
 
-       err = snprintf(lbuf, sizeof(lbuf), "%d\n", ent->total_mrs);
+       err = snprintf(lbuf, sizeof(lbuf), "%ld\n", ent->stored + ent->in_use);
        if (err < 0)
                return err;
 
@@ -689,13 +684,19 @@ struct mlx5_ib_mr *mlx5_mr_cache_alloc(struct mlx5_ib_dev *dev,
                return ERR_PTR(-EOPNOTSUPP);
 
        xa_lock_irq(&ent->mkeys);
+       ent->in_use++;
+
        if (!ent->stored) {
                queue_adjust_cache_locked(ent);
                ent->miss++;
                xa_unlock_irq(&ent->mkeys);
                mr = create_cache_mr(ent);
-               if (IS_ERR(mr))
+               if (IS_ERR(mr)) {
+                       xa_lock_irq(&ent->mkeys);
+                       ent->in_use--;
+                       xa_unlock_irq(&ent->mkeys);
                        return mr;
+               }
        } else {
                mr = pop_stored_mkey(ent);
                queue_adjust_cache_locked(ent);
@@ -716,7 +717,6 @@ static void clean_keys(struct mlx5_ib_dev *dev, int c)
        xa_lock_irq(&ent->mkeys);
        while (ent->stored) {
                mr = pop_stored_mkey(ent);
-               ent->total_mrs--;
                xa_unlock_irq(&ent->mkeys);
                mlx5_core_destroy_mkey(dev->mdev, mr->mmkey.key);
                kfree(mr);
@@ -1642,13 +1642,13 @@ int mlx5_ib_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata)
 
        /* Stop DMA */
        if (mr->cache_ent) {
+               xa_lock_irq(&mr->cache_ent->mkeys);
+               mr->cache_ent->in_use--;
+               xa_unlock_irq(&mr->cache_ent->mkeys);
+
                if (mlx5r_umr_revoke_mr(mr) ||
-                   push_mkey(mr->cache_ent, false, mr)) {
-                       xa_lock_irq(&mr->cache_ent->mkeys);
-                       mr->cache_ent->total_mrs--;
-                       xa_unlock_irq(&mr->cache_ent->mkeys);
+                   push_mkey(mr->cache_ent, false, mr))
                        mr->cache_ent = NULL;
-               }
        }
        if (!mr->cache_ent) {
                rc = destroy_mkey(to_mdev(mr->ibmr.device), mr);