[dpdk-dev] [PATCH v2 5/8] net/ice/base: add capability list AQ function

[Qi Zhang <qi.z.zhang@intel.com>]

The current implementation for reading device and function capabilities
from firmware, ice_aq_discover_caps, has potentially undesirable
side effects.

ice_aq_discover_caps calls ice_parse_caps, resulting in overwriting the
capabilities stored in the hw structure. This is ok during
initialization, but means that code which wants to read the capabilities
after initialization cannot use ice_aq_discover_caps without being
careful of the side effects.

Factor out the AQ command logic into a new ice_aq_list_caps function.
This will be used by the ice_aq_discover_caps function.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Paul M Stillwell Jr <paul.m.stillwell.jr@intel.com>
Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
---
 drivers/net/ice/base/ice_common.c | 62 +++++++++++++++++++++++++++++++--------
 1 file changed, 50 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ice/base/ice_common.c b/drivers/net/ice/base/ice_common.c
index cab81e0fc..33e29bc0e 100644
--- a/drivers/net/ice/base/ice_common.c
+++ b/drivers/net/ice/base/ice_common.c
@@ -2007,20 +2007,27 @@ ice_parse_caps(struct ice_hw *hw, void *buf, u32 cap_count,
 }
 
 /**
- * ice_aq_discover_caps - query function/device capabilities
+ * ice_aq_list_caps - query function/device capabilities
  * @hw: pointer to the HW struct
- * @buf: a virtual buffer to hold the capabilities
- * @buf_size: Size of the virtual buffer
- * @cap_count: cap count needed if AQ err==ENOMEM
- * @opc: capabilities type to discover - pass in the command opcode
+ * @buf: a buffer to hold the capabilities
+ * @buf_size: size of the buffer
+ * @cap_count: if not NULL, set to the number of capabilities reported
+ * @opc: capabilities type to discover, device or function
  * @cd: pointer to command details structure or NULL
  *
- * Get the function(0x000a)/device(0x000b) capabilities description from
- * the firmware.
+ * Get the function (0x000A) or device (0x000B) capabilities description from
+ * firmware and store it in the buffer.
+ *
+ * If the cap_count pointer is not NULL, then it is set to the number of
+ * capabilities firmware will report. Note that if the buffer size is too
+ * small, it is possible the command will return ICE_AQ_ERR_ENOMEM. The
+ * cap_count will still be updated in this case. It is recommended that the
+ * buffer size be set to ICE_AQ_MAX_BUF_LEN (the largest possible buffer that
+ * firmware could return) to avoid this.
  */
 static enum ice_status
-ice_aq_discover_caps(struct ice_hw *hw, void *buf, u16 buf_size, u32 *cap_count,
-		     enum ice_adminq_opc opc, struct ice_sq_cd *cd)
+ice_aq_list_caps(struct ice_hw *hw, void *buf, u16 buf_size, u32 *cap_count,
+		 enum ice_adminq_opc opc, struct ice_sq_cd *cd)
 {
 	struct ice_aqc_list_caps *cmd;
 	struct ice_aq_desc desc;
@@ -2033,12 +2040,43 @@ ice_aq_discover_caps(struct ice_hw *hw, void *buf, u16 buf_size, u32 *cap_count,
 		return ICE_ERR_PARAM;
 
 	ice_fill_dflt_direct_cmd_desc(&desc, opc);
-
 	status = ice_aq_send_cmd(hw, &desc, buf, buf_size, cd);
+
+	if (cap_count)
+		*cap_count = LE32_TO_CPU(cmd->count);
+
+	return status;
+}
+
+/**
+ * ice_aq_discover_caps - query function/device capabilities
+ * @hw: pointer to the HW struct
+ * @buf: a virtual buffer to hold the capabilities
+ * @buf_size: Size of the virtual buffer
+ * @cap_count: cap count needed if AQ err==ENOMEM
+ * @opc: capabilities type to discover - pass in the command opcode
+ * @cd: pointer to command details structure or NULL
+ *
+ * Get the function(0x000a)/device(0x000b) capabilities description from
+ * the firmware.
+ *
+ * NOTE: this function has the side effect of updating the hw->dev_caps or
+ * hw->func_caps by way of calling ice_parse_caps.
+ */
+static enum ice_status
+ice_aq_discover_caps(struct ice_hw *hw, void *buf, u16 buf_size, u32 *cap_count,
+		     enum ice_adminq_opc opc, struct ice_sq_cd *cd)
+{
+	u32 local_cap_count = 0;
+	enum ice_status status;
+
+	status = ice_aq_list_caps(hw, buf, buf_size, &local_cap_count,
+				  opc, cd);
 	if (!status)
-		ice_parse_caps(hw, buf, LE32_TO_CPU(cmd->count), opc);
+		ice_parse_caps(hw, buf, local_cap_count, opc);
 	else if (hw->adminq.sq_last_status == ICE_AQ_RC_ENOMEM)
-		*cap_count = LE32_TO_CPU(cmd->count);
+		*cap_count = local_cap_count;
+
 	return status;
 }
 
-- 
2.13.6