mlx4_core: Fix integer overflow issues around MTT table

Fix some issues around int variables used in data structures related
to memory registration.

Handle int overflow in mlx4_init_icm_table by using a u64 intermediate
variable and changing struct mlx4_icm_table num_obj field to be u32.

Change some more fields/variables to use u32 instead of int to prevent
a case where the variable becomes negative when bit 31 is set.

Also subtract log_mtts_per_seg from the exponent when computing
num_mtt, since its added later on in that very same code area.

This and the previous commit fixes some issues which actually prevent
commit db5a7a65c058 ("mlx4_core: Scale size of MTT table with system
RAM") from working.  Now, when the number of MTTs is scaled with the
size of the RAM we can map up to 8TB.

Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Jack Morgenstein <jackm@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

5 files changed, 13 insertions, 10 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/icm.c b/drivers/net/ethernet/mellanox/mlx4/icm.c
index 88b7b3e75ab..daf41792366 100644
--- a/drivers/net/ethernet/mellanox/mlx4/icm.c
+++ b/drivers/net/ethernet/mellanox/mlx4/icm.c
@@ -358,13 +358,14 @@ void mlx4_table_put_range(struct mlx4_dev *dev, struct mlx4_icm_table *table,
 }
 
 int mlx4_init_icm_table(struct mlx4_dev *dev, struct mlx4_icm_table *table,
-                        u64 virt, int obj_size, int nobj, int reserved,
+                        u64 virt, int obj_size, u32 nobj, int reserved,
                         int use_lowmem, int use_coherent)
 {
         int obj_per_chunk;
         int num_icm;
         unsigned chunk_size;
         int i;
+        u64 size;
 
         obj_per_chunk = MLX4_TABLE_CHUNK_SIZE / obj_size;
         num_icm = (nobj + obj_per_chunk - 1) / obj_per_chunk;
@@ -380,10 +381,12 @@ int mlx4_init_icm_table(struct mlx4_dev *dev, struct mlx4_icm_table *table,
         table->coherent = use_coherent;
         mutex_init(&table->mutex);
 
+        size = (u64) nobj * obj_size;
         for (i = 0; i * MLX4_TABLE_CHUNK_SIZE < reserved * obj_size; ++i) {
                 chunk_size = MLX4_TABLE_CHUNK_SIZE;
-                if ((i + 1) * MLX4_TABLE_CHUNK_SIZE > nobj * obj_size)
-                        chunk_size = PAGE_ALIGN(nobj * obj_size - i * MLX4_TABLE_CHUNK_SIZE);
+                if ((i + 1) * MLX4_TABLE_CHUNK_SIZE > size)
+                        chunk_size = PAGE_ALIGN(size -
+                                        i * MLX4_TABLE_CHUNK_SIZE);
 
                 table->icm[i] = mlx4_alloc_icm(dev, chunk_size >> PAGE_SHIFT,
                                                (use_lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
diff --git a/drivers/net/ethernet/mellanox/mlx4/icm.h b/drivers/net/ethernet/mellanox/mlx4/icm.h
index 19e4efc0b34..a67744f5350 100644
--- a/drivers/net/ethernet/mellanox/mlx4/icm.h
+++ b/drivers/net/ethernet/mellanox/mlx4/icm.h
@@ -78,7 +78,7 @@ int mlx4_table_get_range(struct mlx4_dev *dev, struct mlx4_icm_table *table,
 void mlx4_table_put_range(struct mlx4_dev *dev, struct mlx4_icm_table *table,
                           int start, int end);
 int mlx4_init_icm_table(struct mlx4_dev *dev, struct mlx4_icm_table *table,
-                        u64 virt, int obj_size, int nobj, int reserved,
+                        u64 virt, int obj_size, u32 nobj, int reserved,
                         int use_lowmem, int use_coherent);
 void mlx4_cleanup_icm_table(struct mlx4_dev *dev, struct mlx4_icm_table *table);
 void *mlx4_table_find(struct mlx4_icm_table *table, int obj, dma_addr_t *dma_handle);
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4.h b/drivers/net/ethernet/mellanox/mlx4/mlx4.h
index 59ebc033963..4d9df8f2a12 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4.h
@@ -249,7 +249,7 @@ struct mlx4_bitmap {
 struct mlx4_buddy {
         unsigned long         **bits;
         unsigned int           *num_free;
-        int                     max_order;
+        u32                     max_order;
         spinlock_t              lock;
 };
 
@@ -258,7 +258,7 @@ struct mlx4_icm;
 struct mlx4_icm_table {
         u64                     virt;
         int                     num_icm;
-        int                     num_obj;
+        u32                     num_obj;
         int                     obj_size;
         int                     lowmem;
         int                     coherent;
diff --git a/drivers/net/ethernet/mellanox/mlx4/mr.c b/drivers/net/ethernet/mellanox/mlx4/mr.c
index d6a3a392a37..44b8e1ea1cd 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mr.c
+++ b/drivers/net/ethernet/mellanox/mlx4/mr.c
@@ -678,7 +678,7 @@ int mlx4_init_mr_table(struct mlx4_dev *dev)
                 return err;
 
         err = mlx4_buddy_init(&mr_table->mtt_buddy,
-                              ilog2(dev->caps.num_mtts /
+                              ilog2((u32)dev->caps.num_mtts /
                               (1 << log_mtts_per_seg)));
         if (err)
                 goto err_buddy;
@@ -688,7 +688,7 @@ int mlx4_init_mr_table(struct mlx4_dev *dev)
                         mlx4_alloc_mtt_range(dev,
                                              fls(dev->caps.reserved_mtts - 1));
                 if (priv->reserved_mtts < 0) {
-                        mlx4_warn(dev, "MTT table of order %d is too small.\n",
+                        mlx4_warn(dev, "MTT table of order %u is too small.\n",
                                   mr_table->mtt_buddy.max_order);
                         err = -ENOMEM;
                         goto err_reserve_mtts;
diff --git a/drivers/net/ethernet/mellanox/mlx4/profile.c b/drivers/net/ethernet/mellanox/mlx4/profile.c
index 9ee4725363d..8e0c3cc2a1e 100644
--- a/drivers/net/ethernet/mellanox/mlx4/profile.c
+++ b/drivers/net/ethernet/mellanox/mlx4/profile.c
@@ -76,7 +76,7 @@ u64 mlx4_make_profile(struct mlx4_dev *dev,
                 u64 size;
                 u64 start;
                 int type;
-                int num;
+                u32 num;
                 int log_num;
         };
 
@@ -105,7 +105,7 @@ u64 mlx4_make_profile(struct mlx4_dev *dev,
         si_meminfo(&si);
         request->num_mtt =
                 roundup_pow_of_two(max_t(unsigned, request->num_mtt,
-                                         min(1UL << 31,
+                                         min(1UL << (31 - log_mtts_per_seg),
                                              si.totalram >> (log_mtts_per_seg - 1))));
 
         profile[MLX4_RES_QP].size     = dev_cap->qpc_entry_sz;