From: Yishai Hadas <yishaih@mellanox.com>
Date: Mon, 7 May 2018 10:20:01 +0300
Subject: RDMA/mlx5: Don't assume that medium blueFlame register exists
Patch-mainline: v4.17-rc7
Git-commit: 18b0362e87dfa09e355093b897b9db854e360d28
References: bsc#1046305 FATE#322943
User can leave system without medium BlueFlames registers,
however the code assumed that at least one such register exists.
This patch fixes that assumption.
Fixes: c1be5232d21d ("IB/mlx5: Fix micro UAR allocator")
Reported-by: Rohit Zambre <rzambre@uci.edu>
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/infiniband/hw/mlx5/qp.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
--- a/drivers/infiniband/hw/mlx5/qp.c
+++ b/drivers/infiniband/hw/mlx5/qp.c
@@ -481,11 +481,6 @@ static int qp_has_rq(struct ib_qp_init_a
return 1;
}
-static int first_med_bfreg(void)
-{
- return 1;
-}
-
enum {
/* this is the first blue flame register in the array of bfregs assigned
* to a processes. Since we do not use it for blue flame but rather
@@ -511,6 +506,12 @@ static int num_med_bfreg(struct mlx5_ib_
return n >= 0 ? n : 0;
}
+static int first_med_bfreg(struct mlx5_ib_dev *dev,
+ struct mlx5_bfreg_info *bfregi)
+{
+ return num_med_bfreg(dev, bfregi) ? 1 : -ENOMEM;
+}
+
static int first_hi_bfreg(struct mlx5_ib_dev *dev,
struct mlx5_bfreg_info *bfregi)
{
@@ -538,10 +539,13 @@ static int alloc_high_class_bfreg(struct
static int alloc_med_class_bfreg(struct mlx5_ib_dev *dev,
struct mlx5_bfreg_info *bfregi)
{
- int minidx = first_med_bfreg();
+ int minidx = first_med_bfreg(dev, bfregi);
int i;
- for (i = first_med_bfreg(); i < first_hi_bfreg(dev, bfregi); i++) {
+ if (minidx < 0)
+ return minidx;
+
+ for (i = minidx; i < first_hi_bfreg(dev, bfregi); i++) {
if (bfregi->count[i] < bfregi->count[minidx])
minidx = i;
if (!bfregi->count[minidx])