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From:   longli@linuxonhyperv.com
To:     "K. Y. Srinivasan" <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Stephen Hemminger <sthemmin@microsoft.com>,
        Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        Leon Romanovsky <leon@kernel.org>, edumazet@google.com,
        shiraz.saleem@intel.com, Ajay Sharma <sharmaajay@microsoft.com>
Cc:     linux-hyperv@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org,
        Long Li <longli@microsoft.com>
Subject: [Patch v6 09/12] net: mana: Define max values for SGL entries
Date:   Tue, 20 Sep 2022 18:22:29 -0700
Message-Id: <1663723352-598-10-git-send-email-longli@linuxonhyperv.com>
In-Reply-To: <1663723352-598-1-git-send-email-longli@linuxonhyperv.com>
References: <1663723352-598-1-git-send-email-longli@linuxonhyperv.com>
Reply-To: longli@microsoft.com
Precedence: bulk

From: Long Li <longli@microsoft.com>

The number of maximum SGl entries should be computed from the maximum
WQE size for the intended queue type and the corresponding OOB data
size. This guarantees the hardware queue can successfully queue requests
up to the queue depth exposed to the upper layer.

Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Long Li <longli@microsoft.com>
Acked-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/net/ethernet/microsoft/mana/mana_en.c | 2 +-
 include/net/mana/gdma.h                       | 7 +++++++
 include/net/mana/mana.h                       | 4 +---
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index a79a57644ec3..08d15effc824 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -189,7 +189,7 @@ int mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	pkg.wqe_req.client_data_unit = 0;
 
 	pkg.wqe_req.num_sge = 1 + skb_shinfo(skb)->nr_frags;
-	WARN_ON_ONCE(pkg.wqe_req.num_sge > 30);
+	WARN_ON_ONCE(pkg.wqe_req.num_sge > MAX_TX_WQE_SGL_ENTRIES);
 
 	if (pkg.wqe_req.num_sge <= ARRAY_SIZE(pkg.sgl_array)) {
 		pkg.wqe_req.sgl = pkg.sgl_array;
diff --git a/include/net/mana/gdma.h b/include/net/mana/gdma.h
index 0ee3615152b8..9b050aabf76e 100644
--- a/include/net/mana/gdma.h
+++ b/include/net/mana/gdma.h
@@ -431,6 +431,13 @@ struct gdma_wqe {
 #define MAX_TX_WQE_SIZE 512
 #define MAX_RX_WQE_SIZE 256
 
+#define MAX_TX_WQE_SGL_ENTRIES	((GDMA_MAX_SQE_SIZE -			   \
+			sizeof(struct gdma_sge) - INLINE_OOB_SMALL_SIZE) / \
+			sizeof(struct gdma_sge))
+
+#define MAX_RX_WQE_SGL_ENTRIES	((GDMA_MAX_RQE_SIZE -			   \
+			sizeof(struct gdma_sge)) / sizeof(struct gdma_sge))
+
 struct gdma_cqe {
 	u32 cqe_data[GDMA_COMP_DATA_SIZE / 4];
 
diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index 6e9e86fb4c02..713a8f8cca9a 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -265,8 +265,6 @@ struct mana_cq {
 	int budget;
 };
 
-#define GDMA_MAX_RQE_SGES 15
-
 struct mana_recv_buf_oob {
 	/* A valid GDMA work request representing the data buffer. */
 	struct gdma_wqe_request wqe_req;
@@ -276,7 +274,7 @@ struct mana_recv_buf_oob {
 
 	/* SGL of the buffer going to be sent has part of the work request. */
 	u32 num_sge;
-	struct gdma_sge sgl[GDMA_MAX_RQE_SGES];
+	struct gdma_sge sgl[MAX_RX_WQE_SGL_ENTRIES];
 
 	/* Required to store the result of mana_gd_post_work_request.
 	 * gdma_posted_wqe_info.wqe_size_in_bu is required for progressing the
-- 
2.17.1