mt76: mt7615: add debugfs knob for setting extended local mac addresses

This is primarily for testing and can be used in combination with monitor
mode to make the card respond to packets sent to a specific MAC address.
For now this is only exposed as a debug/testing feature, later on the
approach might be used to support more concurrent station interfaces
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7615/debugfs.c

@@ -365,6 +365,93 @@ mt7615_rf_reg_get(void *data, u64 *val)
 DEFINE_DEBUGFS_ATTRIBUTE(fops_rf_reg, mt7615_rf_reg_get, mt7615_rf_reg_set,
 			 "0x%08llx\n");
 
+static ssize_t
+mt7615_ext_mac_addr_read(struct file *file, char __user *userbuf,
+			 size_t count, loff_t *ppos)
+{
+	struct mt7615_dev *dev = file->private_data;
+	char buf[32 * ((ETH_ALEN * 3) + 4) + 1];
+	u8 addr[ETH_ALEN];
+	int ofs = 0;
+	int i;
+
+	for (i = 0; i < 32; i++) {
+		if (!(dev->muar_mask & BIT(i)))
+			continue;
+
+		mt76_wr(dev, MT_WF_RMAC_MAR1,
+			FIELD_PREP(MT_WF_RMAC_MAR1_IDX, i * 2) |
+			MT_WF_RMAC_MAR1_START);
+		put_unaligned_le32(mt76_rr(dev, MT_WF_RMAC_MAR0), addr);
+		put_unaligned_le16((mt76_rr(dev, MT_WF_RMAC_MAR1) &
+				    MT_WF_RMAC_MAR1_ADDR), addr + 4);
+		ofs += snprintf(buf + ofs, sizeof(buf) - ofs, "%d=%pM\n", i, addr);
+	}
+
+	return simple_read_from_buffer(userbuf, count, ppos, buf, ofs);
+}
+
+static ssize_t
+mt7615_ext_mac_addr_write(struct file *file, const char __user *userbuf,
+			  size_t count, loff_t *ppos)
+{
+	struct mt7615_dev *dev = file->private_data;
+	unsigned long idx = 0;
+	u8 addr[ETH_ALEN];
+	char buf[32];
+	char *p;
+
+	if (count > sizeof(buf))
+		return -EINVAL;
+
+	if (copy_from_user(buf, userbuf, count))
+		return -EFAULT;
+
+	buf[sizeof(buf) - 1] = '\0';
+
+	p = strchr(buf, '=');
+	if (p) {
+		*p = 0;
+		p++;
+
+		if (kstrtoul(buf, 0, &idx) || idx > 31)
+			return -EINVAL;
+	} else {
+		idx = 0;
+		p = buf;
+	}
+
+	if (!mac_pton(p, addr))
+		return -EINVAL;
+
+	if (is_valid_ether_addr(addr)) {
+		dev->muar_mask |= BIT(idx);
+	} else {
+		memset(addr, 0, sizeof(addr));
+		dev->muar_mask &= ~BIT(idx);
+	}
+
+	mt76_rmw_field(dev, MT_WF_RMAC_MORE(0), MT_WF_RMAC_MORE_MUAR_MODE, 1);
+	mt76_wr(dev, MT_WF_RMAC_MAR0, get_unaligned_le32(addr));
+	mt76_wr(dev, MT_WF_RMAC_MAR1,
+		get_unaligned_le16(addr + 4) |
+		FIELD_PREP(MT_WF_RMAC_MAR1_IDX, idx * 2) |
+		MT_WF_RMAC_MAR1_START |
+		MT_WF_RMAC_MAR1_WRITE);
+
+	mt76_rmw_field(dev, MT_WF_RMAC_MORE(0), MT_WF_RMAC_MORE_MUAR_MODE, !!dev->muar_mask);
+
+	return count;
+}
+
+static const struct file_operations fops_ext_mac_addr = {
+	.open = simple_open,
+	.llseek = generic_file_llseek,
+	.read = mt7615_ext_mac_addr_read,
+	.write = mt7615_ext_mac_addr_write,
+	.owner = THIS_MODULE,
+};
+
 int mt7615_init_debugfs(struct mt7615_dev *dev)
 {
 	struct dentry *dir;
@@ -406,6 +493,7 @@ int mt7615_init_debugfs(struct mt7615_dev *dev)
 			    &fops_reset_test);
 	debugfs_create_devm_seqfile(dev->mt76.dev, "temperature", dir,
 				    mt7615_read_temperature);
+	debugfs_create_file("ext_mac_addr", 0600, dir, dev, &fops_ext_mac_addr);
 
 	debugfs_create_u32("rf_wfidx", 0600, dir, &dev->debugfs_rf_wf);
 	debugfs_create_u32("rf_regidx", 0600, dir, &dev->debugfs_rf_reg);

drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h

@@ -295,6 +295,8 @@ struct mt7615_dev {
 	u32 debugfs_rf_wf;
 	u32 debugfs_rf_reg;
 
+	u32 muar_mask;
+
 #ifdef CONFIG_NL80211_TESTMODE
 	struct {
 		u32 *reg_backup;

drivers/net/wireless/mediatek/mt76/mt7615/regs.h

@@ -333,6 +333,9 @@ enum mt7615_reg_base {
 #define MT_WF_RFCR_DROP_NDPA		BIT(20)
 #define MT_WF_RFCR_DROP_UNWANTED_CTL	BIT(21)
 
+#define MT_WF_RMAC_MORE(_band)		MT_WF_RMAC((_band) ? 0x124 : 0x024)
+#define MT_WF_RMAC_MORE_MUAR_MODE	GENMASK(31, 30)
+
 #define MT_WF_RFCR1(_band)		MT_WF_RMAC((_band) ? 0x104 : 0x004)
 #define MT_WF_RFCR1_DROP_ACK		BIT(4)
 #define MT_WF_RFCR1_DROP_BF_POLL	BIT(5)
@@ -342,6 +345,14 @@ enum mt7615_reg_base {
 
 #define MT_CHFREQ(_band)		MT_WF_RMAC((_band) ? 0x130 : 0x030)
 
+#define MT_WF_RMAC_MAR0			MT_WF_RMAC(0x025c)
+#define MT_WF_RMAC_MAR1			MT_WF_RMAC(0x0260)
+#define MT_WF_RMAC_MAR1_ADDR		GENMASK(15, 0)
+#define MT_WF_RMAC_MAR1_START		BIT(16)
+#define MT_WF_RMAC_MAR1_WRITE		BIT(17)
+#define MT_WF_RMAC_MAR1_IDX		GENMASK(29, 24)
+#define MT_WF_RMAC_MAR1_GROUP		GENMASK(31, 30)
+
 #define MT_WF_RMAC_MIB_TIME0		MT_WF_RMAC(0x03c4)
 #define MT_WF_RMAC_MIB_RXTIME_CLR	BIT(31)
 #define MT_WF_RMAC_MIB_RXTIME_EN	BIT(30)