ath11k: add read variant from SMBIOS for download board data

This is to read variant from SMBIOS such as read from DT, the variant
string will be used to one part of string which used to search board
data from board-2.bin.

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3
Signed-off-by: Wen Gong <quic_wgong@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20220315104721.26649-3-quic_wgong@quicinc.com

drivers/net/wireless/ath/ath11k/core.c

@@ -9,6 +9,7 @@
 #include <linux/remoteproc.h>
 #include <linux/firmware.h>
 #include <linux/of.h>
+
 #include "core.h"
 #include "dp_tx.h"
 #include "dp_rx.h"
@@ -548,6 +549,75 @@ int ath11k_core_resume(struct ath11k_base *ab)
 }
 EXPORT_SYMBOL(ath11k_core_resume);
 
+static void ath11k_core_check_bdfext(const struct dmi_header *hdr, void *data)
+{
+	struct ath11k_base *ab = data;
+	const char *magic = ATH11K_SMBIOS_BDF_EXT_MAGIC;
+	struct ath11k_smbios_bdf *smbios = (struct ath11k_smbios_bdf *)hdr;
+	ssize_t copied;
+	size_t len;
+	int i;
+
+	if (ab->qmi.target.bdf_ext[0] != '\0')
+		return;
+
+	if (hdr->type != ATH11K_SMBIOS_BDF_EXT_TYPE)
+		return;
+
+	if (hdr->length != ATH11K_SMBIOS_BDF_EXT_LENGTH) {
+		ath11k_dbg(ab, ATH11K_DBG_BOOT,
+			   "wrong smbios bdf ext type length (%d).\n",
+			   hdr->length);
+		return;
+	}
+
+	if (!smbios->bdf_enabled) {
+		ath11k_dbg(ab, ATH11K_DBG_BOOT, "bdf variant name not found.\n");
+		return;
+	}
+
+	/* Only one string exists (per spec) */
+	if (memcmp(smbios->bdf_ext, magic, strlen(magic)) != 0) {
+		ath11k_dbg(ab, ATH11K_DBG_BOOT,
+			   "bdf variant magic does not match.\n");
+		return;
+	}
+
+	len = min_t(size_t,
+		    strlen(smbios->bdf_ext), sizeof(ab->qmi.target.bdf_ext));
+	for (i = 0; i < len; i++) {
+		if (!isascii(smbios->bdf_ext[i]) || !isprint(smbios->bdf_ext[i])) {
+			ath11k_dbg(ab, ATH11K_DBG_BOOT,
+				   "bdf variant name contains non ascii chars.\n");
+			return;
+		}
+	}
+
+	/* Copy extension name without magic prefix */
+	copied = strscpy(ab->qmi.target.bdf_ext, smbios->bdf_ext + strlen(magic),
+			 sizeof(ab->qmi.target.bdf_ext));
+	if (copied < 0) {
+		ath11k_dbg(ab, ATH11K_DBG_BOOT,
+			   "bdf variant string is longer than the buffer can accommodate\n");
+		return;
+	}
+
+	ath11k_dbg(ab, ATH11K_DBG_BOOT,
+		   "found and validated bdf variant smbios_type 0x%x bdf %s\n",
+		   ATH11K_SMBIOS_BDF_EXT_TYPE, ab->qmi.target.bdf_ext);
+}
+
+int ath11k_core_check_smbios(struct ath11k_base *ab)
+{
+	ab->qmi.target.bdf_ext[0] = '\0';
+	dmi_walk(ath11k_core_check_bdfext, ab);
+
+	if (ab->qmi.target.bdf_ext[0] == '\0')
+		return -ENODATA;
+
+	return 0;
+}
+
 int ath11k_core_check_dt(struct ath11k_base *ab)
 {
 	size_t max_len = sizeof(ab->qmi.target.bdf_ext);

drivers/net/wireless/ath/ath11k/core.h

@@ -10,6 +10,8 @@
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/bitfield.h>
+#include <linux/dmi.h>
+#include <linux/ctype.h>
 #include "qmi.h"
 #include "htc.h"
 #include "wmi.h"
@@ -37,6 +39,15 @@
 #define ATH11K_INVALID_HW_MAC_ID	0xFF
 #define ATH11K_CONNECTION_LOSS_HZ	(3 * HZ)
 
+/* SMBIOS type containing Board Data File Name Extension */
+#define ATH11K_SMBIOS_BDF_EXT_TYPE 0xF8
+
+/* SMBIOS type structure length (excluding strings-set) */
+#define ATH11K_SMBIOS_BDF_EXT_LENGTH 0x9
+
+/* The magic used by QCA spec */
+#define ATH11K_SMBIOS_BDF_EXT_MAGIC "BDF_"
+
 extern unsigned int ath11k_frame_mode;
 
 #define ATH11K_MON_TIMER_INTERVAL  10
@@ -154,6 +165,13 @@ struct ath11k_ext_irq_grp {
 	struct net_device napi_ndev;
 };
 
+struct ath11k_smbios_bdf {
+	struct dmi_header hdr;
+	u32 padding;
+	u8 bdf_enabled;
+	u8 bdf_ext[];
+};
+
 #define HEHANDLE_CAP_PHYINFO_SIZE       3
 #define HECAP_PHYINFO_SIZE              9
 #define HECAP_MACINFO_SIZE              5
@@ -1046,7 +1064,7 @@ int ath11k_core_fetch_board_data_api_1(struct ath11k_base *ab,
 				       const char *name);
 void ath11k_core_free_bdf(struct ath11k_base *ab, struct ath11k_board_data *bd);
 int ath11k_core_check_dt(struct ath11k_base *ath11k);
-
+int ath11k_core_check_smbios(struct ath11k_base *ab);
 void ath11k_core_halt(struct ath11k *ar);
 int ath11k_core_resume(struct ath11k_base *ab);
 int ath11k_core_suspend(struct ath11k_base *ab);

drivers/net/wireless/ath/ath11k/qmi.c

@@ -2095,6 +2095,10 @@ static int ath11k_qmi_request_target_cap(struct ath11k_base *ab)
 		    ab->qmi.target.fw_build_timestamp,
 		    fw_build_id);
 
+	r = ath11k_core_check_smbios(ab);
+	if (r)
+		ath11k_dbg(ab, ATH11K_DBG_QMI, "SMBIOS bdf variant name not set.\n");
+
 	r = ath11k_core_check_dt(ab);
 	if (r)
 		ath11k_dbg(ab, ATH11K_DBG_QMI, "DT bdf variant name not set.\n");