IB/mlx5: Fix binary compatibility with libmlx5

Commit c1be5232d21d "Fix micro UAR allocator" broke binary compatibility
between libmlx5 and mlx5_ib since it defines a different value to the number of
micro UARs per page, leading to wrong calculation in libmlx5. This patch
defines struct mlx5_ib_alloc_ucontext_req_v2 as an extension to struct
mlx5_ib_alloc_ucontext_req.  The extended size is determined in
mlx5_ib_alloc_ucontext() and in case of old library we use uuarn 0 which works
fine -- this is acheived due to create_user_qp() falling back from high to
medium then to low class where low class will return 0. For new libraries we
use the more sophisticated allocation algorithm.

Issue: 371069

Change-Id: I43b67013e11f4c8dc395b4920118fe2831ffe19d
Fixes: c1be5232d21d ('Fix micro UAR allocator')
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Vladimir Sokolovsky <vlad@mellanox.com>

diff --git a/linux-next-pending/0002-IB-mlx5-Fix-binary-compatibility-with-libmlx5.patch b/linux-next-pending/0002-IB-mlx5-Fix-binary-compatibility-with-libmlx5.patch
new file mode 100644 (file)
index 0000000..2910039
--- /dev/null
+++ b/linux-next-pending/0002-IB-mlx5-Fix-binary-compatibility-with-libmlx5.patch
@@ -0,0 +1,137 @@
+From fd9a38b11b8d486ad052a40015e2fed488bc9083 Mon Sep 17 00:00:00 2001
+From: Eli Cohen <eli@mellanox.com>
+Date: Wed, 29 Jan 2014 14:00:10 +0200
+Subject: [PATCH] IB/mlx5: Fix binary compatibility with libmlx5
+
+Commit c1be5232d21d "Fix micro UAR allocator" broke binary compatibility
+between libmlx5 and mlx5_ib since it defines a different value to the number of
+micro UARs per page, leading to wrong calculation in libmlx5. This patch
+defines struct mlx5_ib_alloc_ucontext_req_v2 as an extension to struct
+mlx5_ib_alloc_ucontext_req.  The extended size is determined in
+mlx5_ib_alloc_ucontext() and in case of old library we use uuarn 0 which works
+fine -- this is acheived due to create_user_qp() falling back from high to
+medium then to low class where low class will return 0. For new libraries we
+use the more sophisticated allocation algorithm.
+
+Issue: 371069
+
+Change-Id: I43b67013e11f4c8dc395b4920118fe2831ffe19d
+Fixes: c1be5232d21d ('Fix micro UAR allocator')
+Signed-off-by: Eli Cohen <eli@mellanox.com>
+---
+ drivers/infiniband/hw/mlx5/main.c | 19 +++++++++++++++++--
+ drivers/infiniband/hw/mlx5/qp.c   | 10 ++++++++--
+ drivers/infiniband/hw/mlx5/user.h |  7 +++++++
+ include/linux/mlx5/driver.h       |  1 +
+ 4 files changed, 33 insertions(+), 4 deletions(-)
+
+diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
+index 9660d093f8cf..f4ef4a24d410 100644
+--- a/drivers/infiniband/hw/mlx5/main.c
++++ b/drivers/infiniband/hw/mlx5/main.c
+@@ -536,24 +536,38 @@ static struct ib_ucontext *mlx5_ib_alloc_ucontext(struct ib_device *ibdev,
+                                                 struct ib_udata *udata)
+ {
+       struct mlx5_ib_dev *dev = to_mdev(ibdev);
+-      struct mlx5_ib_alloc_ucontext_req req;
++      struct mlx5_ib_alloc_ucontext_req_v2 req;
+       struct mlx5_ib_alloc_ucontext_resp resp;
+       struct mlx5_ib_ucontext *context;
+       struct mlx5_uuar_info *uuari;
+       struct mlx5_uar *uars;
+       int gross_uuars;
+       int num_uars;
++      int ver;
+       int uuarn;
+       int err;
+       int i;
++      int reqlen;
+ 
+       if (!dev->ib_active)
+               return ERR_PTR(-EAGAIN);
+ 
+-      err = ib_copy_from_udata(&req, udata, sizeof(req));
++      memset(&req, 0, sizeof(req));
++      reqlen = udata->inlen - sizeof(struct ib_uverbs_cmd_hdr);
++      if (reqlen == sizeof(struct mlx5_ib_alloc_ucontext_req))
++              ver = 0;
++      else if (reqlen == sizeof(struct mlx5_ib_alloc_ucontext_req_v2))
++              ver = 2;
++      else
++              return ERR_PTR(-EINVAL);
++
++      err = ib_copy_from_udata(&req, udata, reqlen);
+       if (err)
+               return ERR_PTR(err);
+ 
++      if (req.flags || req.reserved)
++              return ERR_PTR(-EINVAL);
++
+       if (req.total_num_uuars > MLX5_MAX_UUARS)
+               return ERR_PTR(-ENOMEM);
+ 
+@@ -626,6 +640,7 @@ static struct ib_ucontext *mlx5_ib_alloc_ucontext(struct ib_device *ibdev,
+       if (err)
+               goto out_uars;
+ 
++      uuari->ver = ver;
+       uuari->num_low_latency_uuars = req.num_low_latency_uuars;
+       uuari->uars = uars;
+       uuari->num_uars = num_uars;
+diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
+index 492dc330e907..091576a777e9 100644
+--- a/drivers/infiniband/hw/mlx5/qp.c
++++ b/drivers/infiniband/hw/mlx5/qp.c
+@@ -430,11 +430,17 @@ static int alloc_uuar(struct mlx5_uuar_info *uuari,
+               break;
+ 
+       case MLX5_IB_LATENCY_CLASS_MEDIUM:
+-              uuarn = alloc_med_class_uuar(uuari);
++              if (uuari->ver < 2)
++                      uuarn = -ENOMEM;
++              else
++                      uuarn = alloc_med_class_uuar(uuari);
+               break;
+ 
+       case MLX5_IB_LATENCY_CLASS_HIGH:
+-              uuarn = alloc_high_class_uuar(uuari);
++              if (uuari->ver < 2)
++                      uuarn = -ENOMEM;
++              else
++                      uuarn = alloc_high_class_uuar(uuari);
+               break;
+ 
+       case MLX5_IB_LATENCY_CLASS_FAST_PATH:
+diff --git a/drivers/infiniband/hw/mlx5/user.h b/drivers/infiniband/hw/mlx5/user.h
+index 32a2a5dfc523..0f4f8e42a17f 100644
+--- a/drivers/infiniband/hw/mlx5/user.h
++++ b/drivers/infiniband/hw/mlx5/user.h
+@@ -62,6 +62,13 @@ struct mlx5_ib_alloc_ucontext_req {
+       __u32   num_low_latency_uuars;
+ };
+ 
++struct mlx5_ib_alloc_ucontext_req_v2 {
++      __u32   total_num_uuars;
++      __u32   num_low_latency_uuars;
++      __u32   flags;
++      __u32   reserved;
++};
++
+ struct mlx5_ib_alloc_ucontext_resp {
+       __u32   qp_tab_size;
+       __u32   bf_reg_size;
+diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
+index 554548cd3dd4..32cb18c399c2 100644
+--- a/include/linux/mlx5/driver.h
++++ b/include/linux/mlx5/driver.h
+@@ -227,6 +227,7 @@ struct mlx5_uuar_info {
+        * protect uuar allocation data structs
+        */
+       struct mutex            lock;
++      u32                     ver;
+ };
+ 
+ struct mlx5_bf {
+-- 
+1.8.5.2
+