[PATCH v2 1/1] i40e: validate ring_len parameter against hardware-specific values.

[gregory.herrero@oracle.com]

From: Gregory Herrero <gregory.herrero@oracle.com>

The maximum number of descriptors supported by the hardware is hardware
dependent and can be retrieved using i40e_get_max_num_descriptors().
Move this function to a shared header and use it when checking for valid
ring_len parameter rather than using hardcoded value.
Cast info->ring_len to u32 in i40e_config_vsi_tx_queue() as it's u16 in
struct virtchnl_txq_info.
Also cast it in i40e_config_vsi_rx_queue() even if it's u32 in
virtchnl_rxq_info to ease stable backport in case this changed.

By fixing an over-acceptance issue, behavior change could be seen where
ring_len would now be rejected whereas it was not before.

Fixes: 55d225670def ("i40e: add validation for ring_len param")
Signed-off-by: Gregory Herrero <gregory.herrero@oracle.com>
---
 drivers/net/ethernet/intel/i40e/i40e.h          | 17 +++++++++++++++++
 drivers/net/ethernet/intel/i40e/i40e_ethtool.c  | 12 ------------
 .../net/ethernet/intel/i40e/i40e_virtchnl_pf.c  |  4 ++--
 3 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index 801a57a925da..a953cce008f4 100644
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -1418,4 +1418,21 @@ static inline struct i40e_veb *i40e_pf_get_main_veb(struct i40e_pf *pf)
 	return (pf->lan_veb != I40E_NO_VEB) ? pf->veb[pf->lan_veb] : NULL;
 }
 
+/**
+ * i40e_get_max_num_descriptors - get maximum number of descriptors for this hardware.
+ * @pf: pointer to a PF
+ *
+ * Return: u32 value corresponding to the maximum number of descriptors.
+ **/
+static inline u32 i40e_get_max_num_descriptors(const struct i40e_pf *pf)
+{
+	const struct i40e_hw *hw = &pf->hw;
+
+	switch (hw->mac.type) {
+	case I40E_MAC_XL710:
+		return I40E_MAX_NUM_DESCRIPTORS_XL710;
+	default:
+		return I40E_MAX_NUM_DESCRIPTORS;
+	}
+}
 #endif /* _I40E_H_ */
diff --git a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
index 86c72596617a..61c39e881b00 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
@@ -2013,18 +2013,6 @@ static void i40e_get_drvinfo(struct net_device *netdev,
 		drvinfo->n_priv_flags += I40E_GL_PRIV_FLAGS_STR_LEN;
 }
 
-static u32 i40e_get_max_num_descriptors(struct i40e_pf *pf)
-{
-	struct i40e_hw *hw = &pf->hw;
-
-	switch (hw->mac.type) {
-	case I40E_MAC_XL710:
-		return I40E_MAX_NUM_DESCRIPTORS_XL710;
-	default:
-		return I40E_MAX_NUM_DESCRIPTORS;
-	}
-}
-
 static void i40e_get_ringparam(struct net_device *netdev,
 			       struct ethtool_ringparam *ring,
 			       struct kernel_ethtool_ringparam *kernel_ring,
diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
index 081a4526a2f0..5e058159057b 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -656,7 +656,7 @@ static int i40e_config_vsi_tx_queue(struct i40e_vf *vf, u16 vsi_id,
 
 	/* ring_len has to be multiple of 8 */
 	if (!IS_ALIGNED(info->ring_len, 8) ||
-	    info->ring_len > I40E_MAX_NUM_DESCRIPTORS_XL710) {
+	    (u32)info->ring_len > i40e_get_max_num_descriptors(pf)) {
 		ret = -EINVAL;
 		goto error_context;
 	}
@@ -726,7 +726,7 @@ static int i40e_config_vsi_rx_queue(struct i40e_vf *vf, u16 vsi_id,
 
 	/* ring_len has to be multiple of 32 */
 	if (!IS_ALIGNED(info->ring_len, 32) ||
-	    info->ring_len > I40E_MAX_NUM_DESCRIPTORS_XL710) {
+	    (u32)info->ring_len > i40e_get_max_num_descriptors(pf)) {
 		ret = -EINVAL;
 		goto error_param;
 	}
-- 
2.51.0