IB/mlx5: Decrease memory consumption of mr caches

Change the logic so we do not allocate memory nor map the device
before actually posting to the REG_UMR QP. In addition, unmap and free
the memory after we get completion.

Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 22 insertions, 35 deletions

diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index e86dbbdb3836..06e33e6cb07f 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -61,13 +61,11 @@ static int order2idx(struct mlx5_ib_dev *dev, int order)
 
 static int add_keys(struct mlx5_ib_dev *dev, int c, int num)
 {
-        struct device *ddev = dev->ib_dev.dma_device;
         struct mlx5_mr_cache *cache = &dev->cache;
         struct mlx5_cache_ent *ent = &cache->ent[c];
         struct mlx5_create_mkey_mbox_in *in;
         struct mlx5_ib_mr *mr;
         int npages = 1 << ent->order;
-        int size = sizeof(u64) * npages;
         int err = 0;
         int i;
 
@@ -83,21 +81,6 @@ static int add_keys(struct mlx5_ib_dev *dev, int c, int num)
                 }
                 mr->order = ent->order;
                 mr->umred = 1;
-                mr->pas = kmalloc(size + 0x3f, GFP_KERNEL);
-                if (!mr->pas) {
-                        kfree(mr);
-                        err = -ENOMEM;
-                        goto out;
-                }
-                mr->dma = dma_map_single(ddev, mr_align(mr->pas, 0x40), size,
-                                         DMA_TO_DEVICE);
-                if (dma_mapping_error(ddev, mr->dma)) {
-                        kfree(mr->pas);
-                        kfree(mr);
-                        err = -ENOMEM;
-                        goto out;
-                }
-
                 in->seg.status = 1 << 6;
                 in->seg.xlt_oct_size = cpu_to_be32((npages + 1) / 2);
                 in->seg.qpn_mkey7_0 = cpu_to_be32(0xffffff << 8);
@@ -108,8 +91,6 @@ static int add_keys(struct mlx5_ib_dev *dev, int c, int num)
                                             sizeof(*in));
                 if (err) {
                         mlx5_ib_warn(dev, "create mkey failed %d\n", err);
-                        dma_unmap_single(ddev, mr->dma, size, DMA_TO_DEVICE);
-                        kfree(mr->pas);
                         kfree(mr);
                         goto out;
                 }
@@ -129,11 +110,9 @@ out:
 
 static void remove_keys(struct mlx5_ib_dev *dev, int c, int num)
 {
-        struct device *ddev = dev->ib_dev.dma_device;
         struct mlx5_mr_cache *cache = &dev->cache;
         struct mlx5_cache_ent *ent = &cache->ent[c];
         struct mlx5_ib_mr *mr;
-        int size;
         int err;
         int i;
 
@@ -149,14 +128,10 @@ static void remove_keys(struct mlx5_ib_dev *dev, int c, int num)
                 ent->size--;
                 spin_unlock(&ent->lock);
                 err = mlx5_core_destroy_mkey(&dev->mdev, &mr->mmr);
-                if (err) {
+                if (err)
                         mlx5_ib_warn(dev, "failed destroy mkey\n");
-                } else {
-                        size = ALIGN(sizeof(u64) * (1 << mr->order), 0x40);
-                        dma_unmap_single(ddev, mr->dma, size, DMA_TO_DEVICE);
-                        kfree(mr->pas);
+                else
                         kfree(mr);
-                }
         }
 }
 
@@ -408,11 +383,9 @@ static void free_cached_mr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)
 
 static void clean_keys(struct mlx5_ib_dev *dev, int c)
 {
-        struct device *ddev = dev->ib_dev.dma_device;
         struct mlx5_mr_cache *cache = &dev->cache;
         struct mlx5_cache_ent *ent = &cache->ent[c];
         struct mlx5_ib_mr *mr;
-        int size;
         int err;
 
         cancel_delayed_work(&ent->dwork);
@@ -428,14 +401,10 @@ static void clean_keys(struct mlx5_ib_dev *dev, int c)
                 ent->size--;
                 spin_unlock(&ent->lock);
                 err = mlx5_core_destroy_mkey(&dev->mdev, &mr->mmr);
-                if (err) {
+                if (err)
                         mlx5_ib_warn(dev, "failed destroy mkey\n");
-                } else {
-                        size = ALIGN(sizeof(u64) * (1 << mr->order), 0x40);
-                        dma_unmap_single(ddev, mr->dma, size, DMA_TO_DEVICE);
-                        kfree(mr->pas);
+                else
                         kfree(mr);
-                }
         }
 }
 
@@ -678,10 +647,12 @@ static struct mlx5_ib_mr *reg_umr(struct ib_pd *pd, struct ib_umem *umem,
                                   int page_shift, int order, int access_flags)
 {
         struct mlx5_ib_dev *dev = to_mdev(pd->device);
+        struct device *ddev = dev->ib_dev.dma_device;
         struct umr_common *umrc = &dev->umrc;
         struct ib_send_wr wr, *bad;
         struct mlx5_ib_mr *mr;
         struct ib_sge sg;
+        int size = sizeof(u64) * npages;
         int err;
         int i;
 
@@ -700,6 +671,19 @@ static struct mlx5_ib_mr *reg_umr(struct ib_pd *pd, struct ib_umem *umem,
         if (!mr)
                 return ERR_PTR(-EAGAIN);
 
+        mr->pas = kmalloc(size + 0x3f, GFP_KERNEL);
+        if (!mr->pas) {
+                err = -ENOMEM;
+                goto error;
+        }
+        mr->dma = dma_map_single(ddev, mr_align(mr->pas, 0x40), size,
+                                 DMA_TO_DEVICE);
+        if (dma_mapping_error(ddev, mr->dma)) {
+                kfree(mr->pas);
+                err = -ENOMEM;
+                goto error;
+        }
+
         mlx5_ib_populate_pas(dev, umem, page_shift, mr_align(mr->pas, 0x40), 1);
 
         memset(&wr, 0, sizeof(wr));
@@ -721,6 +705,9 @@ static struct mlx5_ib_mr *reg_umr(struct ib_pd *pd, struct ib_umem *umem,
         wait_for_completion(&mr->done);
         up(&umrc->sem);
 
+        dma_unmap_single(ddev, mr->dma, size, DMA_TO_DEVICE);
+        kfree(mr->pas);
+
         if (mr->status != IB_WC_SUCCESS) {
                 mlx5_ib_warn(dev, "reg umr failed\n");
                 err = -EFAULT;