Subject: [PATCH 27/35] qed: Limit msix vectors in kdump kernel to the minimum required count.

From: Sudarsana Reddy Kalluru <[email-masked]>
Date: Sun, 1 Jul 2018 20:03:05 -0700

[ Upstream commit bb7858ba1102f82470a917e041fd23e6385c31be ]

Memory size is limited in the kdump kernel environment. Allocation of more
msix-vectors (or queues) consumes few tens of MBs of memory, which might
lead to the kdump kernel failure.
This patch adds changes to limit the number of MSI-X vectors in kdump
kernel to minimum required value (i.e., 2 per engine).

Fixes: fe56b9e6a ("qed: Add module with basic common support")
Signed-off-by: Sudarsana Reddy Kalluru <[email-masked]>
Signed-off-by: Michal Kalderon <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 drivers/net/ethernet/qlogic/qed/qed_main.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/net/ethernet/qlogic/qed/qed_main.c b/drivers/net/ethernet/qlogic/qed/qed_main.c
index 27832885a87f..2c958921dfb3 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_main.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_main.c
@@ -779,6 +779,14 @@ static int qed_slowpath_setup_int(struct qed_dev *cdev,
 	/* We want a minimum of one slowpath and one fastpath vector per hwfn */
 	cdev->int_params.in.min_msix_cnt = cdev->num_hwfns * 2;
 
+	if (is_kdump_kernel()) {
+		DP_INFO(cdev,
+			"Kdump kernel: Limit the max number of requested MSI-X vectors to %hd\n",
+			cdev->int_params.in.min_msix_cnt);
+		cdev->int_params.in.num_vectors =
+			cdev->int_params.in.min_msix_cnt;
+	}
+
 	rc = qed_set_int_mode(cdev, false);
 	if (rc)  {
 		DP_ERR(cdev, "qed_slowpath_setup_int ERR\n");
-- 
2.17.1