mlx4_core: Write MTTs from CPU instead with of WRITE_MTT FW command

Write MTT entries directly to ICM from the driver (eliminating use of
WRITE_MTT command).  This reduces the number of FW commands needed to
register an MR by at least a factor of 2 and speeds up memory
registration significantly.  This code will also be used to implement
FMRs.

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Michael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

diff --git a/drivers/infiniband/hw/mlx4/mr.c b/drivers/infiniband/hw/mlx4/mr.c
index 85ae906f1d12815d1f4d207db071f1c4432dc3f5..734ec2bd15cd58229abe5fb1e59f1503eada5a94 100644 (file)
--- a/drivers/infiniband/hw/mlx4/mr.c
+++ b/drivers/infiniband/hw/mlx4/mr.c
@@ -96,11 +96,10 @@ int mlx4_ib_umem_write_mtt(struct mlx4_ib_dev *dev, struct mlx4_mtt *mtt,
                                pages[i++] = sg_dma_address(&chunk->page_list[j]) +
                                        umem->page_size * k;
                                /*
-                                * Be friendly to WRITE_MTT firmware
-                                * command, and pass it chunks of
-                                * appropriate size.
+                                * Be friendly to mlx4_write_mtt() and
+                                * pass it chunks of appropriate size.
                                 */
-                               if (i == PAGE_SIZE / sizeof (u64) - 2) {
+                               if (i == PAGE_SIZE / sizeof (u64)) {
                                        err = mlx4_write_mtt(dev->dev, mtt, n,
                                                             i, pages);
                                        if (err)

diff --git a/drivers/net/mlx4/icm.c b/drivers/net/mlx4/icm.c
index 250e2488757880ada43cdc3d68a983f90823b83b..4b3c109d5eaee2d6f7c73a5a31db57bca749c053 100644 (file)
--- a/drivers/net/mlx4/icm.c
+++ b/drivers/net/mlx4/icm.c
@@ -301,9 +301,9 @@ void mlx4_table_put(struct mlx4_dev *dev, struct mlx4_icm_table *table, int obj)
        mutex_unlock(&table->mutex);
 }
 
-void *mlx4_table_find(struct mlx4_icm_table *table, int obj)
+void *mlx4_table_find(struct mlx4_icm_table *table, int obj, dma_addr_t *dma_handle)
 {
-       int idx, offset, i;
+       int idx, offset, dma_offset, i;
        struct mlx4_icm_chunk *chunk;
        struct mlx4_icm *icm;
        struct page *page = NULL;
@@ -313,15 +313,26 @@ void *mlx4_table_find(struct mlx4_icm_table *table, int obj)
 
        mutex_lock(&table->mutex);
 
-       idx = obj & (table->num_obj - 1);
-       icm = table->icm[idx / (MLX4_TABLE_CHUNK_SIZE / table->obj_size)];
-       offset = idx % (MLX4_TABLE_CHUNK_SIZE / table->obj_size);
+       idx = (obj & (table->num_obj - 1)) * table->obj_size;
+       icm = table->icm[idx / MLX4_TABLE_CHUNK_SIZE];
+       dma_offset = offset = idx % MLX4_TABLE_CHUNK_SIZE;
 
        if (!icm)
                goto out;
 
        list_for_each_entry(chunk, &icm->chunk_list, list) {
                for (i = 0; i < chunk->npages; ++i) {
+                       if (dma_handle && dma_offset >= 0) {
+                               if (sg_dma_len(&chunk->mem[i]) > dma_offset)
+                                       *dma_handle = sg_dma_address(&chunk->mem[i]) +
+                                               dma_offset;
+                               dma_offset -= sg_dma_len(&chunk->mem[i]);
+                       }
+                       /*
+                        * DMA mapping can merge pages but not split them,
+                        * so if we found the page, dma_handle has already
+                        * been assigned to.
+                        */
                        if (chunk->mem[i].length > offset) {
                                page = chunk->mem[i].page;
                                goto out;

diff --git a/drivers/net/mlx4/icm.h b/drivers/net/mlx4/icm.h
index a77db6de8597a5581a8e99b91aac371757195b6a..6c44edf35847e07c1de518f2bc78d4dbe70947b7 100644 (file)
--- a/drivers/net/mlx4/icm.h
+++ b/drivers/net/mlx4/icm.h
@@ -83,7 +83,7 @@ int mlx4_init_icm_table(struct mlx4_dev *dev, struct mlx4_icm_table *table,
 void mlx4_cleanup_icm_table(struct mlx4_dev *dev, struct mlx4_icm_table *table);
 int mlx4_table_get(struct mlx4_dev *dev, struct mlx4_icm_table *table, int obj);
 void mlx4_table_put(struct mlx4_dev *dev, struct mlx4_icm_table *table, int obj);
-void *mlx4_table_find(struct mlx4_icm_table *table, int obj);
+void *mlx4_table_find(struct mlx4_icm_table *table, int obj, dma_addr_t *dma_handle);
 int mlx4_table_get_range(struct mlx4_dev *dev, struct mlx4_icm_table *table,
                         int start, int end);
 void mlx4_table_put_range(struct mlx4_dev *dev, struct mlx4_icm_table *table,

diff --git a/drivers/net/mlx4/main.c b/drivers/net/mlx4/main.c
index ed7e8d76cde04899b293f51fdd9998e2487eb126..478b3ba74edc42fcd4afdd56b6bafdd8bc14f666 100644 (file)
--- a/drivers/net/mlx4/main.c
+++ b/drivers/net/mlx4/main.c
@@ -300,6 +300,17 @@ static int __devinit mlx4_init_icm(struct mlx4_dev *dev,
                goto err_unmap_cmpt;
        }
 
+       /*
+        * Reserved MTT entries must be aligned up to a cacheline
+        * boundary, since the FW will write to them, while the driver
+        * writes to all other MTT entries. (The variable
+        * dev->caps.mtt_entry_sz below is really the MTT segment
+        * size, not the raw entry size)
+        */
+       dev->caps.reserved_mtts =
+               ALIGN(dev->caps.reserved_mtts * dev->caps.mtt_entry_sz,
+                     dma_get_cache_alignment()) / dev->caps.mtt_entry_sz;
+
        err = mlx4_init_icm_table(dev, &priv->mr_table.mtt_table,
                                  init_hca->mtt_base,
                                  dev->caps.mtt_entry_sz,

diff --git a/drivers/net/mlx4/mr.c b/drivers/net/mlx4/mr.c
index 60a6ee27cfd49f927acf16d75d4e0fe9ad8317a5..3cc98c699aaf5e82c9fbc466503771650435f959 100644 (file)
--- a/drivers/net/mlx4/mr.c
+++ b/drivers/net/mlx4/mr.c
@@ -349,58 +349,57 @@ err_table:
 }
 EXPORT_SYMBOL_GPL(mlx4_mr_enable);
 
-static int mlx4_WRITE_MTT(struct mlx4_dev *dev, struct mlx4_cmd_mailbox *mailbox,
-                         int num_mtt)
+static int mlx4_write_mtt_chunk(struct mlx4_dev *dev, struct mlx4_mtt *mtt,
+                               int start_index, int npages, u64 *page_list)
 {
-       return mlx4_cmd(dev, mailbox->dma, num_mtt, 0, MLX4_CMD_WRITE_MTT,
-                       MLX4_CMD_TIME_CLASS_B);
+       struct mlx4_priv *priv = mlx4_priv(dev);
+       __be64 *mtts;
+       dma_addr_t dma_handle;
+       int i;
+       int s = start_index * sizeof (u64);
+
+       /* All MTTs must fit in the same page */
+       if (start_index / (PAGE_SIZE / sizeof (u64)) !=
+           (start_index + npages - 1) / (PAGE_SIZE / sizeof (u64)))
+               return -EINVAL;
+
+       if (start_index & (MLX4_MTT_ENTRY_PER_SEG - 1))
+               return -EINVAL;
+
+       mtts = mlx4_table_find(&priv->mr_table.mtt_table, mtt->first_seg +
+                               s / dev->caps.mtt_entry_sz, &dma_handle);
+       if (!mtts)
+               return -ENOMEM;
+
+       for (i = 0; i < npages; ++i)
+               mtts[i] = cpu_to_be64(page_list[i] | MLX4_MTT_FLAG_PRESENT);
+
+       dma_sync_single(&dev->pdev->dev, dma_handle, npages * sizeof (u64), DMA_TO_DEVICE);
+
+       return 0;
 }
 
 int mlx4_write_mtt(struct mlx4_dev *dev, struct mlx4_mtt *mtt,
                   int start_index, int npages, u64 *page_list)
 {
-       struct mlx4_cmd_mailbox *mailbox;
-       __be64 *mtt_entry;
-       int i;
-       int err = 0;
+       int chunk;
+       int err;
 
        if (mtt->order < 0)
                return -EINVAL;
 
-       mailbox = mlx4_alloc_cmd_mailbox(dev);
-       if (IS_ERR(mailbox))
-               return PTR_ERR(mailbox);
-
-       mtt_entry = mailbox->buf;
-
        while (npages > 0) {
-               mtt_entry[0] = cpu_to_be64(mlx4_mtt_addr(dev, mtt) + start_index * 8);
-               mtt_entry[1] = 0;
-
-               for (i = 0; i < npages && i < MLX4_MAILBOX_SIZE / 8 - 2; ++i)
-                       mtt_entry[i + 2] = cpu_to_be64(page_list[i] |
-                                                      MLX4_MTT_FLAG_PRESENT);
-
-               /*
-                * If we have an odd number of entries to write, add
-                * one more dummy entry for firmware efficiency.
-                */
-               if (i & 1)
-                       mtt_entry[i + 2] = 0;
-
-               err = mlx4_WRITE_MTT(dev, mailbox, (i + 1) & ~1);
+               chunk = min_t(int, PAGE_SIZE / sizeof(u64), npages);
+               err = mlx4_write_mtt_chunk(dev, mtt, start_index, chunk, page_list);
                if (err)
-                       goto out;
+                       return err;
 
-               npages      -= i;
-               start_index += i;
-               page_list   += i;
+               npages      -= chunk;
+               start_index += chunk;
+               page_list   += chunk;
        }
 
-out:
-       mlx4_free_cmd_mailbox(dev, mailbox);
-
-       return err;
+       return 0;
 }
 EXPORT_SYMBOL_GPL(mlx4_write_mtt);