net/ice/base: support reading REPC statistics

The GLV_REPC register contains statistics for tracking received packets
that are discarded due to certain errors.

This register behaves differently from some of the other related
statistics registers in two ways. First, it contains two 16bit
statistics, and thus cannot be read as a 32bit or 40bit statistic.

Second, the two stats do not roll over, but instead cap at 0xFFFF.

Add a new ice_stat_update_repc function which will read the register and
increment the appropriate statistics in the ice_eth_stats structure.

Since the register does not roll over, make use of the "Write Clear"
behavior, and write to the register to reset it every time we read it.

Add extra space for the two statistics that are counted by this
register, rx_errors, and rx_no_desc.

For now, wrap the new function and stats counters in !LINUX_SUPPORT.
This can later be removed if and when the Linux driver implements
support for reading the statistics.

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>
Acked-by: Xiaolong Ye <xiaolong.ye@intel.com>

diff --git a/drivers/net/ice/base/ice_common.c b/drivers/net/ice/base/ice_common.c
index 6b28f62..36434ee 100644 (file)
--- a/drivers/net/ice/base/ice_common.c
+++ b/drivers/net/ice/base/ice_common.c
@@ -4253,6 +4253,57 @@ ice_stat_update32(struct ice_hw *hw, u32 reg, bool prev_stat_loaded,
        *prev_stat = new_data;
 }
 
+/**
+ * ice_stat_update_repc - read GLV_REPC stats from chip and update stat values
+ * @hw: ptr to the hardware info
+ * @vsi_handle: VSI handle
+ * @prev_stat_loaded: bool to specify if the previous stat values are loaded
+ * @cur_stats: ptr to current stats structure
+ *
+ * The GLV_REPC statistic register actually tracks two 16bit statistics, and
+ * thus cannot be read using the normal ice_stat_update32 function.
+ *
+ * Read the GLV_REPC register associated with the given VSI, and update the
+ * rx_no_desc and rx_error values in the ice_eth_stats structure.
+ *
+ * Because the statistics in GLV_REPC stick at 0xFFFF, the register must be
+ * cleared each time it's read.
+ *
+ * Note that the GLV_RDPC register also counts the causes that would trigger
+ * GLV_REPC. However, it does not give the finer grained detail about why the
+ * packets are being dropped. The GLV_REPC values can be used to distinguish
+ * whether Rx packets are dropped due to errors or due to no available
+ * descriptors.
+ */
+void
+ice_stat_update_repc(struct ice_hw *hw, u16 vsi_handle, bool prev_stat_loaded,
+                    struct ice_eth_stats *cur_stats)
+{
+       u16 vsi_num, no_desc, error_cnt;
+       u32 repc;
+
+       if (!ice_is_vsi_valid(hw, vsi_handle))
+               return;
+
+       vsi_num = ice_get_hw_vsi_num(hw, vsi_handle);
+
+       /* If we haven't loaded stats yet, just clear the current value */
+       if (!prev_stat_loaded) {
+               wr32(hw, GLV_REPC(vsi_num), 0);
+               return;
+       }
+
+       repc = rd32(hw, GLV_REPC(vsi_num));
+       no_desc = (repc & GLV_REPC_NO_DESC_CNT_M) >> GLV_REPC_NO_DESC_CNT_S;
+       error_cnt = (repc & GLV_REPC_ERROR_CNT_M) >> GLV_REPC_ERROR_CNT_S;
+
+       /* Clear the count by writing to the stats register */
+       wr32(hw, GLV_REPC(vsi_num), 0);
+
+       cur_stats->rx_no_desc += no_desc;
+       cur_stats->rx_errors += error_cnt;
+}
+
 
 /**
  * ice_sched_query_elem - query element information from HW

diff --git a/drivers/net/ice/base/ice_common.h b/drivers/net/ice/base/ice_common.h
index a8104df..1fd256a 100644 (file)
--- a/drivers/net/ice/base/ice_common.h
+++ b/drivers/net/ice/base/ice_common.h
@@ -211,6 +211,9 @@ void
 ice_stat_update32(struct ice_hw *hw, u32 reg, bool prev_stat_loaded,
                  u64 *prev_stat, u64 *cur_stat);
 void
+ice_stat_update_repc(struct ice_hw *hw, u16 vsi_handle, bool prev_stat_loaded,
+                    struct ice_eth_stats *cur_stats);
+void
 ice_get_nvm_version(struct ice_hw *hw, u8 *oem_ver, u16 *oem_build,
                    u8 *oem_patch, u8 *ver_hi, u8 *ver_lo);
 enum ice_fw_modes ice_get_fw_mode(struct ice_hw *hw);

diff --git a/drivers/net/ice/base/ice_type.h b/drivers/net/ice/base/ice_type.h
index 7194cb9..0dba94a 100644 (file)
--- a/drivers/net/ice/base/ice_type.h
+++ b/drivers/net/ice/base/ice_type.h
@@ -833,6 +833,8 @@ struct ice_eth_stats {
        u64 tx_broadcast;               /* bptc */
        u64 tx_discards;                /* tdpc */
        u64 tx_errors;                  /* tepc */
+       u64 rx_no_desc;                 /* repc */
+       u64 rx_errors;                  /* repc */
 };
 
 #define ICE_MAX_UP     8