1 files changed, 262 insertions, 4 deletions

diff --git a/drivers/thunderbolt/eeprom.c b/drivers/thunderbolt/eeprom.c
index f28e40231c9e..0d5a80b2d07a 100644
--- a/drivers/thunderbolt/eeprom.c
+++ b/drivers/thunderbolt/eeprom.c
@@ -4,6 +4,7 @@
  * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
  */
 
+#include <linux/crc32.h>
 #include "tb.h"
 
 /**
@@ -152,9 +153,86 @@ static int tb_eeprom_read_n(struct tb_switch *sw, u16 offset, u8 *val,
 	return tb_eeprom_active(sw, false);
 }
 
-int tb_eeprom_read_uid(struct tb_switch *sw, u64 *uid)
+static u8 tb_crc8(u8 *data, int len)
+{
+	int i, j;
+	u8 val = 0xff;
+	for (i = 0; i < len; i++) {
+		val ^= data[i];
+		for (j = 0; j < 8; j++)
+			val = (val << 1) ^ ((val & 0x80) ? 7 : 0);
+	}
+	return val;
+}
+
+static u32 tb_crc32(void *data, size_t len)
+{
+	return ~__crc32c_le(~0, data, len);
+}
+
+#define TB_DROM_DATA_START 13
+struct tb_drom_header {
+	/* BYTE 0 */
+	u8 uid_crc8; /* checksum for uid */
+	/* BYTES 1-8 */
+	u64 uid;
+	/* BYTES 9-12 */
+	u32 data_crc32; /* checksum for data_len bytes starting at byte 13 */
+	/* BYTE 13 */
+	u8 device_rom_revision; /* should be <= 1 */
+	u16 data_len:10;
+	u8 __unknown1:6;
+	/* BYTES 16-21 */
+	u16 vendor_id;
+	u16 model_id;
+	u8 model_rev;
+	u8 eeprom_rev;
+} __packed;
+
+enum tb_drom_entry_type {
+	TB_DROM_ENTRY_GENERIC,
+	TB_DROM_ENTRY_PORT,
+};
+
+struct tb_drom_entry_header {
+	u8 len;
+	u8 index:6;
+	bool port_disabled:1; /* only valid if type is TB_DROM_ENTRY_PORT */
+	enum tb_drom_entry_type type:1;
+} __packed;
+
+struct tb_drom_entry_port {
+	/* BYTES 0-1 */
+	struct tb_drom_entry_header header;
+	/* BYTE 2 */
+	u8 dual_link_port_rid:4;
+	u8 link_nr:1;
+	u8 unknown1:2;
+	bool has_dual_link_port:1;
+
+	/* BYTE 3 */
+	u8 dual_link_port_nr:6;
+	u8 unknown2:2;
+
+	/* BYTES 4 - 5 TODO decode */
+	u8 micro2:4;
+	u8 micro1:4;
+	u8 micro3;
+
+	/* BYTES 5-6, TODO: verify (find hardware that has these set) */
+	u8 peer_port_rid:4;
+	u8 unknown3:3;
+	bool has_peer_port:1;
+	u8 peer_port_nr:6;
+	u8 unknown4:2;
+} __packed;
+
+
+/**
+ * tb_eeprom_get_drom_offset - get drom offset within eeprom
+ */
+int tb_eeprom_get_drom_offset(struct tb_switch *sw, u16 *offset)
 {
-	u8 data[9];
 	struct tb_cap_plug_events cap;
 	int res;
 	if (!sw->cap_plug_events) {
@@ -165,6 +243,7 @@ int tb_eeprom_read_uid(struct tb_switch *sw, u64 *uid)
 			     sizeof(cap) / 4);
 	if (res)
 		return res;
+
 	if (!cap.eeprom_ctl.present || cap.eeprom_ctl.not_present) {
 		tb_sw_warn(sw, "no NVM\n");
 		return -ENOSYS;
@@ -175,15 +254,194 @@ int tb_eeprom_read_uid(struct tb_switch *sw, u64 *uid)
 				cap.drom_offset);
 		return -ENXIO;
 	}
+	*offset = cap.drom_offset;
+	return 0;
+}
+
+/**
+ * tb_drom_read_uid_only - read uid directly from drom
+ *
+ * Does not use the cached copy in sw->drom. Used during resume to check switch
+ * identity.
+ */
+int tb_drom_read_uid_only(struct tb_switch *sw, u64 *uid)
+{
+	u8 data[9];
+	u16 drom_offset;
+	u8 crc;
+	int res = tb_eeprom_get_drom_offset(sw, &drom_offset);
+	if (res)
+		return res;
 
 	/* read uid */
-	res = tb_eeprom_read_n(sw, cap.drom_offset, data, 9);
+	res = tb_eeprom_read_n(sw, drom_offset, data, 9);
 	if (res)
 		return res;
-	/* TODO: check checksum in data[0] */
+
+	crc = tb_crc8(data + 1, 8);
+	if (crc != data[0]) {
+		tb_sw_warn(sw, "uid crc8 missmatch (expected: %#x, got: %#x)\n",
+				data[0], crc);
+		return -EIO;
+	}
+
 	*uid = *(u64 *)(data+1);
 	return 0;
 }
 
+static void tb_drom_parse_port_entry(struct tb_port *port,
+		struct tb_drom_entry_port *entry)
+{
+	port->link_nr = entry->link_nr;
+	if (entry->has_dual_link_port)
+		port->dual_link_port =
+				&port->sw->ports[entry->dual_link_port_nr];
+}
+
+static int tb_drom_parse_entry(struct tb_switch *sw,
+		struct tb_drom_entry_header *header)
+{
+	struct tb_port *port;
+	int res;
+	enum tb_port_type type;
 
+	if (header->type != TB_DROM_ENTRY_PORT)
+		return 0;
 
+	port = &sw->ports[header->index];
+	port->disabled = header->port_disabled;
+	if (port->disabled)
+		return 0;
+
+	res = tb_port_read(port, &type, TB_CFG_PORT, 2, 1);
+	if (res)
+		return res;
+	type &= 0xffffff;
+
+	if (type == TB_TYPE_PORT) {
+		struct tb_drom_entry_port *entry = (void *) header;
+		if (header->len != sizeof(*entry)) {
+			tb_sw_warn(sw,
+				"port entry has size %#x (expected %#lx)\n",
+				header->len, sizeof(struct tb_drom_entry_port));
+			return -EIO;
+		}
+		tb_drom_parse_port_entry(port, entry);
+	}
+	return 0;
+}
+
+/**
+ * tb_drom_parse_entries - parse the linked list of drom entries
+ *
+ * Drom must have been copied to sw->drom.
+ */
+static int tb_drom_parse_entries(struct tb_switch *sw)
+{
+	struct tb_drom_header *header = (void *) sw->drom;
+	u16 pos = sizeof(*header);
+	u16 drom_size = header->data_len + TB_DROM_DATA_START;
+
+	while (pos < drom_size) {
+		struct tb_drom_entry_header *entry = (void *) (sw->drom + pos);
+		if (pos + 1 == drom_size || pos + entry->len > drom_size
+				|| !entry->len) {
+			tb_sw_warn(sw, "drom buffer overrun, aborting\n");
+			return -EIO;
+		}
+
+		tb_drom_parse_entry(sw, entry);
+
+		pos += entry->len;
+	}
+	return 0;
+}
+
+/**
+ * tb_drom_read - copy drom to sw->drom and parse it
+ */
+int tb_drom_read(struct tb_switch *sw)
+{
+	u16 drom_offset;
+	u16 size;
+	u32 crc;
+	struct tb_drom_header *header;
+	int res;
+	if (sw->drom)
+		return 0;
+
+	if (tb_route(sw) == 0) {
+		/*
+		 * The root switch contains only a dummy drom (header only,
+		 * no entries). Hardcode the configuration here.
+		 */
+		tb_drom_read_uid_only(sw, &sw->uid);
+
+		sw->ports[1].link_nr = 0;
+		sw->ports[2].link_nr = 1;
+		sw->ports[1].dual_link_port = &sw->ports[2];
+		sw->ports[2].dual_link_port = &sw->ports[1];
+
+		sw->ports[3].link_nr = 0;
+		sw->ports[4].link_nr = 1;
+		sw->ports[3].dual_link_port = &sw->ports[4];
+		sw->ports[4].dual_link_port = &sw->ports[3];
+		return 0;
+	}
+
+	res = tb_eeprom_get_drom_offset(sw, &drom_offset);
+	if (res)
+		return res;
+
+	res = tb_eeprom_read_n(sw, drom_offset + 14, (u8 *) &size, 2);
+	if (res)
+		return res;
+	size &= 0x3ff;
+	size += TB_DROM_DATA_START;
+	tb_sw_info(sw, "reading drom (length: %#x)\n", size);
+	if (size < sizeof(*header)) {
+		tb_sw_warn(sw, "drom too small, aborting\n");
+		return -EIO;
+	}
+
+	sw->drom = kzalloc(size, GFP_KERNEL);
+	if (!sw->drom)
+		return -ENOMEM;
+	res = tb_eeprom_read_n(sw, drom_offset, sw->drom, size);
+	if (res)
+		goto err;
+
+	header = (void *) sw->drom;
+
+	if (header->data_len + TB_DROM_DATA_START != size) {
+		tb_sw_warn(sw, "drom size mismatch, aborting\n");
+		goto err;
+	}
+
+	crc = tb_crc8((u8 *) &header->uid, 8);
+	if (crc != header->uid_crc8) {
+		tb_sw_warn(sw,
+			"drom uid crc8 mismatch (expected: %#x, got: %#x), aborting\n",
+			header->uid_crc8, crc);
+		goto err;
+	}
+	sw->uid = header->uid;
+
+	crc = tb_crc32(sw->drom + TB_DROM_DATA_START, header->data_len);
+	if (crc != header->data_crc32) {
+		tb_sw_warn(sw,
+			"drom data crc32 mismatch (expected: %#x, got: %#x), aborting\n",
+			header->data_crc32, crc);
+		goto err;
+	}
+
+	if (header->device_rom_revision > 1)
+		tb_sw_warn(sw, "drom device_rom_revision %#x unknown\n",
+			header->device_rom_revision);
+
+	return tb_drom_parse_entries(sw);
+err:
+	kfree(sw->drom);
+	return -EIO;
+
+}