linux/drivers/thunderbolt/eeprom.c
Mika Westerberg b04079837b thunderbolt: Add initial support for USB4
USB4 is the public specification based on Thunderbolt 3 protocol. There
are some differences in register layouts and flows. In addition to PCIe
and DP tunneling, USB4 supports tunneling of USB 3.x. USB4 is also
backward compatible with Thunderbolt 3 (and older generations but the
spec only talks about 3rd generation). USB4 compliant devices can be
identified by checking USB4 version field in router configuration space.

This patch adds initial support for USB4 compliant hosts and devices
which enables following features provided by the existing functionality
in the driver:

  - PCIe tunneling
  - Display Port tunneling
  - Host and device NVM firmware upgrade
  - P2P networking

This brings the USB4 support to the same level that we already have for
Thunderbolt 1, 2 and 3 devices.

Note the spec talks about host and device "routers" but in the driver we
still use term "switch" in most places. Both can be used interchangeably.

Co-developed-by: Rajmohan Mani <rajmohan.mani@intel.com>
Signed-off-by: Rajmohan Mani <rajmohan.mani@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: https://lore.kernel.org/r/20191217123345.31850-5-mika.westerberg@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-18 15:38:55 +01:00

621 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Thunderbolt driver - eeprom access
*
* Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
* Copyright (C) 2018, Intel Corporation
*/
#include <linux/crc32.h>
#include <linux/property.h>
#include <linux/slab.h>
#include "tb.h"
/**
* tb_eeprom_ctl_write() - write control word
*/
static int tb_eeprom_ctl_write(struct tb_switch *sw, struct tb_eeprom_ctl *ctl)
{
return tb_sw_write(sw, ctl, TB_CFG_SWITCH, sw->cap_plug_events + 4, 1);
}
/**
* tb_eeprom_ctl_write() - read control word
*/
static int tb_eeprom_ctl_read(struct tb_switch *sw, struct tb_eeprom_ctl *ctl)
{
return tb_sw_read(sw, ctl, TB_CFG_SWITCH, sw->cap_plug_events + 4, 1);
}
enum tb_eeprom_transfer {
TB_EEPROM_IN,
TB_EEPROM_OUT,
};
/**
* tb_eeprom_active - enable rom access
*
* WARNING: Always disable access after usage. Otherwise the controller will
* fail to reprobe.
*/
static int tb_eeprom_active(struct tb_switch *sw, bool enable)
{
struct tb_eeprom_ctl ctl;
int res = tb_eeprom_ctl_read(sw, &ctl);
if (res)
return res;
if (enable) {
ctl.access_high = 1;
res = tb_eeprom_ctl_write(sw, &ctl);
if (res)
return res;
ctl.access_low = 0;
return tb_eeprom_ctl_write(sw, &ctl);
} else {
ctl.access_low = 1;
res = tb_eeprom_ctl_write(sw, &ctl);
if (res)
return res;
ctl.access_high = 0;
return tb_eeprom_ctl_write(sw, &ctl);
}
}
/**
* tb_eeprom_transfer - transfer one bit
*
* If TB_EEPROM_IN is passed, then the bit can be retrieved from ctl->data_in.
* If TB_EEPROM_OUT is passed, then ctl->data_out will be written.
*/
static int tb_eeprom_transfer(struct tb_switch *sw, struct tb_eeprom_ctl *ctl,
enum tb_eeprom_transfer direction)
{
int res;
if (direction == TB_EEPROM_OUT) {
res = tb_eeprom_ctl_write(sw, ctl);
if (res)
return res;
}
ctl->clock = 1;
res = tb_eeprom_ctl_write(sw, ctl);
if (res)
return res;
if (direction == TB_EEPROM_IN) {
res = tb_eeprom_ctl_read(sw, ctl);
if (res)
return res;
}
ctl->clock = 0;
return tb_eeprom_ctl_write(sw, ctl);
}
/**
* tb_eeprom_out - write one byte to the bus
*/
static int tb_eeprom_out(struct tb_switch *sw, u8 val)
{
struct tb_eeprom_ctl ctl;
int i;
int res = tb_eeprom_ctl_read(sw, &ctl);
if (res)
return res;
for (i = 0; i < 8; i++) {
ctl.data_out = val & 0x80;
res = tb_eeprom_transfer(sw, &ctl, TB_EEPROM_OUT);
if (res)
return res;
val <<= 1;
}
return 0;
}
/**
* tb_eeprom_in - read one byte from the bus
*/
static int tb_eeprom_in(struct tb_switch *sw, u8 *val)
{
struct tb_eeprom_ctl ctl;
int i;
int res = tb_eeprom_ctl_read(sw, &ctl);
if (res)
return res;
*val = 0;
for (i = 0; i < 8; i++) {
*val <<= 1;
res = tb_eeprom_transfer(sw, &ctl, TB_EEPROM_IN);
if (res)
return res;
*val |= ctl.data_in;
}
return 0;
}
/**
* tb_eeprom_get_drom_offset - get drom offset within eeprom
*/
static int tb_eeprom_get_drom_offset(struct tb_switch *sw, u16 *offset)
{
struct tb_cap_plug_events cap;
int res;
if (!sw->cap_plug_events) {
tb_sw_warn(sw, "no TB_CAP_PLUG_EVENTS, cannot read eeprom\n");
return -ENODEV;
}
res = tb_sw_read(sw, &cap, TB_CFG_SWITCH, sw->cap_plug_events,
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 -ENODEV;
}
if (cap.drom_offset > 0xffff) {
tb_sw_warn(sw, "drom offset is larger than 0xffff: %#x\n",
cap.drom_offset);
return -ENXIO;
}
*offset = cap.drom_offset;
return 0;
}
/**
* tb_eeprom_read_n - read count bytes from offset into val
*/
static int tb_eeprom_read_n(struct tb_switch *sw, u16 offset, u8 *val,
size_t count)
{
u16 drom_offset;
int i, res;
res = tb_eeprom_get_drom_offset(sw, &drom_offset);
if (res)
return res;
offset += drom_offset;
res = tb_eeprom_active(sw, true);
if (res)
return res;
res = tb_eeprom_out(sw, 3);
if (res)
return res;
res = tb_eeprom_out(sw, offset >> 8);
if (res)
return res;
res = tb_eeprom_out(sw, offset);
if (res)
return res;
for (i = 0; i < count; i++) {
res = tb_eeprom_in(sw, val + i);
if (res)
return res;
}
return tb_eeprom_active(sw, false);
}
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 {
/* force unsigned to prevent "one-bit signed bitfield" warning */
TB_DROM_ENTRY_GENERIC = 0U,
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_generic {
struct tb_drom_entry_header header;
u8 data[0];
} __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 6-7, 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_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];
u8 crc;
int res;
/* read uid */
res = tb_eeprom_read_n(sw, 0, data, 9);
if (res)
return res;
crc = tb_crc8(data + 1, 8);
if (crc != data[0]) {
tb_sw_warn(sw, "uid crc8 mismatch (expected: %#x, got: %#x)\n",
data[0], crc);
return -EIO;
}
*uid = *(u64 *)(data+1);
return 0;
}
static int tb_drom_parse_entry_generic(struct tb_switch *sw,
struct tb_drom_entry_header *header)
{
const struct tb_drom_entry_generic *entry =
(const struct tb_drom_entry_generic *)header;
switch (header->index) {
case 1:
/* Length includes 2 bytes header so remove it before copy */
sw->vendor_name = kstrndup(entry->data,
header->len - sizeof(*header), GFP_KERNEL);
if (!sw->vendor_name)
return -ENOMEM;
break;
case 2:
sw->device_name = kstrndup(entry->data,
header->len - sizeof(*header), GFP_KERNEL);
if (!sw->device_name)
return -ENOMEM;
break;
}
return 0;
}
static int tb_drom_parse_entry_port(struct tb_switch *sw,
struct tb_drom_entry_header *header)
{
struct tb_port *port;
int res;
enum tb_port_type type;
/*
* Some DROMs list more ports than the controller actually has
* so we skip those but allow the parser to continue.
*/
if (header->index > sw->config.max_port_number) {
dev_info_once(&sw->dev, "ignoring unnecessary extra entries in DROM\n");
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 %#zx)\n",
header->len, sizeof(struct tb_drom_entry_port));
return -EIO;
}
port->link_nr = entry->link_nr;
if (entry->has_dual_link_port)
port->dual_link_port =
&port->sw->ports[entry->dual_link_port_nr];
}
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;
int res;
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;
}
switch (entry->type) {
case TB_DROM_ENTRY_GENERIC:
res = tb_drom_parse_entry_generic(sw, entry);
break;
case TB_DROM_ENTRY_PORT:
res = tb_drom_parse_entry_port(sw, entry);
break;
}
if (res)
return res;
pos += entry->len;
}
return 0;
}
/**
* tb_drom_copy_efi - copy drom supplied by EFI to sw->drom if present
*/
static int tb_drom_copy_efi(struct tb_switch *sw, u16 *size)
{
struct device *dev = &sw->tb->nhi->pdev->dev;
int len, res;
len = device_property_count_u8(dev, "ThunderboltDROM");
if (len < 0 || len < sizeof(struct tb_drom_header))
return -EINVAL;
sw->drom = kmalloc(len, GFP_KERNEL);
if (!sw->drom)
return -ENOMEM;
res = device_property_read_u8_array(dev, "ThunderboltDROM", sw->drom,
len);
if (res)
goto err;
*size = ((struct tb_drom_header *)sw->drom)->data_len +
TB_DROM_DATA_START;
if (*size > len)
goto err;
return 0;
err:
kfree(sw->drom);
sw->drom = NULL;
return -EINVAL;
}
static int tb_drom_copy_nvm(struct tb_switch *sw, u16 *size)
{
u32 drom_offset;
int ret;
if (!sw->dma_port)
return -ENODEV;
ret = tb_sw_read(sw, &drom_offset, TB_CFG_SWITCH,
sw->cap_plug_events + 12, 1);
if (ret)
return ret;
if (!drom_offset)
return -ENODEV;
ret = dma_port_flash_read(sw->dma_port, drom_offset + 14, size,
sizeof(*size));
if (ret)
return ret;
/* Size includes CRC8 + UID + CRC32 */
*size += 1 + 8 + 4;
sw->drom = kzalloc(*size, GFP_KERNEL);
if (!sw->drom)
return -ENOMEM;
ret = dma_port_flash_read(sw->dma_port, drom_offset, sw->drom, *size);
if (ret)
goto err_free;
/*
* Read UID from the minimal DROM because the one in NVM is just
* a placeholder.
*/
tb_drom_read_uid_only(sw, &sw->uid);
return 0;
err_free:
kfree(sw->drom);
sw->drom = NULL;
return ret;
}
static int usb4_copy_host_drom(struct tb_switch *sw, u16 *size)
{
int ret;
ret = usb4_switch_drom_read(sw, 14, size, sizeof(*size));
if (ret)
return ret;
/* Size includes CRC8 + UID + CRC32 */
*size += 1 + 8 + 4;
sw->drom = kzalloc(*size, GFP_KERNEL);
if (!sw->drom)
return -ENOMEM;
ret = usb4_switch_drom_read(sw, 0, sw->drom, *size);
if (ret) {
kfree(sw->drom);
sw->drom = NULL;
}
return ret;
}
static int tb_drom_read_n(struct tb_switch *sw, u16 offset, u8 *val,
size_t count)
{
if (tb_switch_is_usb4(sw))
return usb4_switch_drom_read(sw, offset, val, count);
return tb_eeprom_read_n(sw, offset, val, count);
}
/**
* tb_drom_read - copy drom to sw->drom and parse it
*/
int tb_drom_read(struct tb_switch *sw)
{
u16 size;
u32 crc;
struct tb_drom_header *header;
int res;
if (sw->drom)
return 0;
if (tb_route(sw) == 0) {
/*
* Apple's NHI EFI driver supplies a DROM for the root switch
* in a device property. Use it if available.
*/
if (tb_drom_copy_efi(sw, &size) == 0)
goto parse;
/* Non-Apple hardware has the DROM as part of NVM */
if (tb_drom_copy_nvm(sw, &size) == 0)
goto parse;
/*
* USB4 hosts may support reading DROM through router
* operations.
*/
if (tb_switch_is_usb4(sw)) {
usb4_switch_read_uid(sw, &sw->uid);
if (!usb4_copy_host_drom(sw, &size))
goto parse;
} else {
/*
* The root switch contains only a dummy drom
* (header only, no entries). Hardcode the
* configuration here.
*/
tb_drom_read_uid_only(sw, &sw->uid);
}
return 0;
}
res = tb_drom_read_n(sw, 14, (u8 *) &size, 2);
if (res)
return res;
size &= 0x3ff;
size += TB_DROM_DATA_START;
tb_sw_dbg(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_drom_read_n(sw, 0, sw->drom, size);
if (res)
goto err;
parse:
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;
}
if (!sw->uid)
sw->uid = header->uid;
sw->vendor = header->vendor_id;
sw->device = header->model_id;
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), continuing\n",
header->data_crc32, crc);
}
if (header->device_rom_revision > 2)
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);
sw->drom = NULL;
return -EIO;
}