[PATCH net-next v2 2/9] bnxt_en: add support for retrieving crash dump using ethtool

[Michael Chan <michael.chan@broadcom.com>]

From: Vikas Gupta <vikas.gupta@broadcom.com>

Add support for retrieving crash dump using ethtool -w on the
supported interface.

Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Vikas Gupta <vikas.gupta@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
 .../ethernet/broadcom/bnxt/bnxt_coredump.c    | 83 +++++++++++++++++--
 .../net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 13 ++-
 2 files changed, 87 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_coredump.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_coredump.c
index ebbad9ccab6a..9ed915e4c618 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_coredump.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_coredump.c
@@ -372,14 +372,78 @@ static int __bnxt_get_coredump(struct bnxt *bp, void *buf, u32 *dump_len)
 	return rc;
 }
 
+static u32 bnxt_copy_crash_data(struct bnxt_ring_mem_info *rmem, void *buf,
+				u32 dump_len)
+{
+	u32 data_copied = 0;
+	u32 data_len;
+	int i;
+
+	for (i = 0; i < rmem->nr_pages; i++) {
+		data_len = rmem->page_size;
+		if (data_copied + data_len > dump_len)
+			data_len = dump_len - data_copied;
+		memcpy(buf + data_copied, rmem->pg_arr[i], data_len);
+		data_copied += data_len;
+		if (data_copied >= dump_len)
+			break;
+	}
+	return data_copied;
+}
+
+static int bnxt_copy_crash_dump(struct bnxt *bp, void *buf, u32 dump_len)
+{
+	struct bnxt_ring_mem_info *rmem;
+	u32 offset = 0;
+
+	if (!bp->fw_crash_mem)
+		return -EEXIST;
+
+	rmem = &bp->fw_crash_mem->ring_mem;
+
+	if (rmem->depth > 1) {
+		int i;
+
+		for (i = 0; i < rmem->nr_pages; i++) {
+			struct bnxt_ctx_pg_info *pg_tbl;
+
+			pg_tbl = bp->fw_crash_mem->ctx_pg_tbl[i];
+			offset += bnxt_copy_crash_data(&pg_tbl->ring_mem,
+						       buf + offset,
+						       dump_len - offset);
+			if (offset >= dump_len)
+				break;
+		}
+	} else {
+		bnxt_copy_crash_data(rmem, buf, dump_len);
+	}
+
+	return 0;
+}
+
+static bool bnxt_crash_dump_avail(struct bnxt *bp)
+{
+	u32 sig = 0;
+
+	/* First 4 bytes(signature) of crash dump is always non-zero */
+	bnxt_copy_crash_dump(bp, &sig, sizeof(u32));
+	if (!sig)
+		return false;
+
+	return true;
+}
+
 int bnxt_get_coredump(struct bnxt *bp, u16 dump_type, void *buf, u32 *dump_len)
 {
 	if (dump_type == BNXT_DUMP_CRASH) {
+		if (bp->fw_dbg_cap & DBG_QCAPS_RESP_FLAGS_CRASHDUMP_HOST_DDR)
+			return bnxt_copy_crash_dump(bp, buf, *dump_len);
 #ifdef CONFIG_TEE_BNXT_FW
-		return tee_bnxt_copy_coredump(buf, 0, *dump_len);
-#else
-		return -EOPNOTSUPP;
+		else if (bp->fw_dbg_cap & DBG_QCAPS_RESP_FLAGS_CRASHDUMP_SOC_DDR)
+			return tee_bnxt_copy_coredump(buf, 0, *dump_len);
 #endif
+		else
+			return -EOPNOTSUPP;
 	} else {
 		return __bnxt_get_coredump(bp, buf, dump_len);
 	}
@@ -442,10 +506,17 @@ u32 bnxt_get_coredump_length(struct bnxt *bp, u16 dump_type)
 {
 	u32 len = 0;
 
+	if (dump_type == BNXT_DUMP_CRASH &&
+	    bp->fw_dbg_cap & DBG_QCAPS_RESP_FLAGS_CRASHDUMP_HOST_DDR &&
+	    bp->fw_crash_mem) {
+		if (!bnxt_crash_dump_avail(bp))
+			return 0;
+
+		return bp->fw_crash_len;
+	}
+
 	if (bnxt_hwrm_get_dump_len(bp, dump_type, &len)) {
-		if (dump_type == BNXT_DUMP_CRASH)
-			len = BNXT_CRASH_DUMP_LEN;
-		else
+		if (dump_type != BNXT_DUMP_CRASH)
 			__bnxt_get_coredump(bp, NULL, &len);
 	}
 	return len;
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
index 39eed5831e3a..265956c45ff5 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
@@ -4993,9 +4993,16 @@ static int bnxt_set_dump(struct net_device *dev, struct ethtool_dump *dump)
 		return -EINVAL;
 	}
 
-	if (!IS_ENABLED(CONFIG_TEE_BNXT_FW) && dump->flag == BNXT_DUMP_CRASH) {
-		netdev_info(dev, "Cannot collect crash dump as TEE_BNXT_FW config option is not enabled.\n");
-		return -EOPNOTSUPP;
+	if (dump->flag == BNXT_DUMP_CRASH) {
+		if (bp->fw_dbg_cap & DBG_QCAPS_RESP_FLAGS_CRASHDUMP_SOC_DDR &&
+		    (!IS_ENABLED(CONFIG_TEE_BNXT_FW))) {
+			netdev_info(dev,
+				    "Cannot collect crash dump as TEE_BNXT_FW config option is not enabled.\n");
+			return -EOPNOTSUPP;
+		} else if (!(bp->fw_dbg_cap & DBG_QCAPS_RESP_FLAGS_CRASHDUMP_HOST_DDR)) {
+			netdev_info(dev, "Crash dump collection from host memory is not supported on this interface.\n");
+			return -EOPNOTSUPP;
+		}
 	}
 
 	bp->dump_flag = dump->flag;
-- 
2.30.1