bnxt_en: Fix ethtool -d byte order for 32-bit values

JIRA: https://issues.redhat.com/browse/RHEL-76565

commit 02e8be5
Author: Michael Chan <michael.chan@broadcom.com>
Date:   Mon Apr 28 15:59:03 2025 -0700

    bnxt_en: Fix ethtool -d byte order for 32-bit values

    For version 1 register dump that includes the PCIe stats, the existing
    code incorrectly assumes that all PCIe stats are 64-bit values.  Fix it
    by using an array containing the starting and ending index of the 32-bit
    values.  The loop in bnxt_get_regs() will use the array to do proper
    endian swap for the 32-bit values.

    Fixes: b5d600b ("bnxt_en: Add support for 'ethtool -d'")
    Reviewed-by: Shruti Parab <shruti.parab@broadcom.com>
    Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
    Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
    Signed-off-by: Michael Chan <michael.chan@broadcom.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Shruti Parab <shruti.parab@broadcom.com>

Author: Shruti Parab

drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c

@@ -2071,6 +2071,17 @@ static int bnxt_get_regs_len(struct net_device *dev)
 	return reg_len;
 }
 
+#define BNXT_PCIE_32B_ENTRY(start, end)			\
+	 { offsetof(struct pcie_ctx_hw_stats, start),	\
+	   offsetof(struct pcie_ctx_hw_stats, end) }
+
+static const struct {
+	u16 start;
+	u16 end;
+} bnxt_pcie_32b_entries[] = {
+	BNXT_PCIE_32B_ENTRY(pcie_ltssm_histogram[0], pcie_ltssm_histogram[3]),
+};
+
 static void bnxt_get_regs(struct net_device *dev, struct ethtool_regs *regs,
 			  void *_p)
 {
@@ -2103,12 +2114,27 @@ static void bnxt_get_regs(struct net_device *dev, struct ethtool_regs *regs,
 	req->pcie_stat_host_addr = cpu_to_le64(hw_pcie_stats_addr);
 	rc = hwrm_req_send(bp, req);
 	if (!rc) {
-		__le64 *src = (__le64 *)hw_pcie_stats;
-		u64 *dst = (u64 *)(_p + BNXT_PXP_REG_LEN);
-		int i;
-
-		for (i = 0; i < sizeof(*hw_pcie_stats) / sizeof(__le64); i++)
-			dst[i] = le64_to_cpu(src[i]);
+		u8 *dst = (u8 *)(_p + BNXT_PXP_REG_LEN);
+		u8 *src = (u8 *)hw_pcie_stats;
+		int i, j;
+
+		for (i = 0, j = 0; i < sizeof(*hw_pcie_stats); ) {
+			if (i >= bnxt_pcie_32b_entries[j].start &&
+			    i <= bnxt_pcie_32b_entries[j].end) {
+				u32 *dst32 = (u32 *)(dst + i);
+
+				*dst32 = le32_to_cpu(*(__le32 *)(src + i));
+				i += 4;
+				if (i > bnxt_pcie_32b_entries[j].end &&
+				    j < ARRAY_SIZE(bnxt_pcie_32b_entries) - 1)
+					j++;
+			} else {
+				u64 *dst64 = (u64 *)(dst + i);
+
+				*dst64 = le64_to_cpu(*(__le64 *)(src + i));
+				i += 8;
+			}
+		}
 	}
 	hwrm_req_drop(bp, req);
 }