blob: 9188c53f5c965f1ec6f8d3e6f598e7c85b5a3894 [file] [log] [blame]
/*
* Copyright © 2014 Red Hat
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting documentation, and
* that the name of the copyright holders not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. The copyright holders make no representations
* about the suitability of this software for any purpose. It is provided "as
* is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*/
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
#include <linux/stacktrace.h>
#include <linux/sort.h>
#include <linux/timekeeping.h>
#include <linux/math64.h>
#endif
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_dp_mst_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
#include "drm_crtc_helper_internal.h"
#include "drm_dp_mst_topology_internal.h"
/**
* DOC: dp mst helper
*
* These functions contain parts of the DisplayPort 1.2a MultiStream Transport
* protocol. The helpers contain a topology manager and bandwidth manager.
* The helpers encapsulate the sending and received of sideband msgs.
*/
struct drm_dp_pending_up_req {
struct drm_dp_sideband_msg_hdr hdr;
struct drm_dp_sideband_msg_req_body msg;
struct list_head next;
};
static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
char *buf);
static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
int id,
struct drm_dp_payload *payload);
static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int offset, int size, u8 *bytes);
static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int offset, int size, u8 *bytes);
static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb);
static void
drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb);
static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_port *port);
static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
u8 *guid);
static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
#define DBG_PREFIX "[dp_mst]"
#define DP_STR(x) [DP_ ## x] = #x
static const char *drm_dp_mst_req_type_str(u8 req_type)
{
static const char * const req_type_str[] = {
DP_STR(GET_MSG_TRANSACTION_VERSION),
DP_STR(LINK_ADDRESS),
DP_STR(CONNECTION_STATUS_NOTIFY),
DP_STR(ENUM_PATH_RESOURCES),
DP_STR(ALLOCATE_PAYLOAD),
DP_STR(QUERY_PAYLOAD),
DP_STR(RESOURCE_STATUS_NOTIFY),
DP_STR(CLEAR_PAYLOAD_ID_TABLE),
DP_STR(REMOTE_DPCD_READ),
DP_STR(REMOTE_DPCD_WRITE),
DP_STR(REMOTE_I2C_READ),
DP_STR(REMOTE_I2C_WRITE),
DP_STR(POWER_UP_PHY),
DP_STR(POWER_DOWN_PHY),
DP_STR(SINK_EVENT_NOTIFY),
DP_STR(QUERY_STREAM_ENC_STATUS),
};
if (req_type >= ARRAY_SIZE(req_type_str) ||
!req_type_str[req_type])
return "unknown";
return req_type_str[req_type];
}
#undef DP_STR
#define DP_STR(x) [DP_NAK_ ## x] = #x
static const char *drm_dp_mst_nak_reason_str(u8 nak_reason)
{
static const char * const nak_reason_str[] = {
DP_STR(WRITE_FAILURE),
DP_STR(INVALID_READ),
DP_STR(CRC_FAILURE),
DP_STR(BAD_PARAM),
DP_STR(DEFER),
DP_STR(LINK_FAILURE),
DP_STR(NO_RESOURCES),
DP_STR(DPCD_FAIL),
DP_STR(I2C_NAK),
DP_STR(ALLOCATE_FAIL),
};
if (nak_reason >= ARRAY_SIZE(nak_reason_str) ||
!nak_reason_str[nak_reason])
return "unknown";
return nak_reason_str[nak_reason];
}
#undef DP_STR
#define DP_STR(x) [DRM_DP_SIDEBAND_TX_ ## x] = #x
static const char *drm_dp_mst_sideband_tx_state_str(int state)
{
static const char * const sideband_reason_str[] = {
DP_STR(QUEUED),
DP_STR(START_SEND),
DP_STR(SENT),
DP_STR(RX),
DP_STR(TIMEOUT),
};
if (state >= ARRAY_SIZE(sideband_reason_str) ||
!sideband_reason_str[state])
return "unknown";
return sideband_reason_str[state];
}
static int
drm_dp_mst_rad_to_str(const u8 rad[8], u8 lct, char *out, size_t len)
{
int i;
u8 unpacked_rad[16];
for (i = 0; i < lct; i++) {
if (i % 2)
unpacked_rad[i] = rad[i / 2] >> 4;
else
unpacked_rad[i] = rad[i / 2] & BIT_MASK(4);
}
/* TODO: Eventually add something to printk so we can format the rad
* like this: 1.2.3
*/
return snprintf(out, len, "%*phC", lct, unpacked_rad);
}
/* sideband msg handling */
static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
{
u8 bitmask = 0x80;
u8 bitshift = 7;
u8 array_index = 0;
int number_of_bits = num_nibbles * 4;
u8 remainder = 0;
while (number_of_bits != 0) {
number_of_bits--;
remainder <<= 1;
remainder |= (data[array_index] & bitmask) >> bitshift;
bitmask >>= 1;
bitshift--;
if (bitmask == 0) {
bitmask = 0x80;
bitshift = 7;
array_index++;
}
if ((remainder & 0x10) == 0x10)
remainder ^= 0x13;
}
number_of_bits = 4;
while (number_of_bits != 0) {
number_of_bits--;
remainder <<= 1;
if ((remainder & 0x10) != 0)
remainder ^= 0x13;
}
return remainder;
}
static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
{
u8 bitmask = 0x80;
u8 bitshift = 7;
u8 array_index = 0;
int number_of_bits = number_of_bytes * 8;
u16 remainder = 0;
while (number_of_bits != 0) {
number_of_bits--;
remainder <<= 1;
remainder |= (data[array_index] & bitmask) >> bitshift;
bitmask >>= 1;
bitshift--;
if (bitmask == 0) {
bitmask = 0x80;
bitshift = 7;
array_index++;
}
if ((remainder & 0x100) == 0x100)
remainder ^= 0xd5;
}
number_of_bits = 8;
while (number_of_bits != 0) {
number_of_bits--;
remainder <<= 1;
if ((remainder & 0x100) != 0)
remainder ^= 0xd5;
}
return remainder & 0xff;
}
static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
{
u8 size = 3;
size += (hdr->lct / 2);
return size;
}
static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
u8 *buf, int *len)
{
int idx = 0;
int i;
u8 crc4;
buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
for (i = 0; i < (hdr->lct / 2); i++)
buf[idx++] = hdr->rad[i];
buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
(hdr->msg_len & 0x3f);
buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
buf[idx - 1] |= (crc4 & 0xf);
*len = idx;
}
static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
u8 *buf, int buflen, u8 *hdrlen)
{
u8 crc4;
u8 len;
int i;
u8 idx;
if (buf[0] == 0)
return false;
len = 3;
len += ((buf[0] & 0xf0) >> 4) / 2;
if (len > buflen)
return false;
crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
return false;
}
hdr->lct = (buf[0] & 0xf0) >> 4;
hdr->lcr = (buf[0] & 0xf);
idx = 1;
for (i = 0; i < (hdr->lct / 2); i++)
hdr->rad[i] = buf[idx++];
hdr->broadcast = (buf[idx] >> 7) & 0x1;
hdr->path_msg = (buf[idx] >> 6) & 0x1;
hdr->msg_len = buf[idx] & 0x3f;
idx++;
hdr->somt = (buf[idx] >> 7) & 0x1;
hdr->eomt = (buf[idx] >> 6) & 0x1;
hdr->seqno = (buf[idx] >> 4) & 0x1;
idx++;
*hdrlen = idx;
return true;
}
void
drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req,
struct drm_dp_sideband_msg_tx *raw)
{
int idx = 0;
int i;
u8 *buf = raw->msg;
buf[idx++] = req->req_type & 0x7f;
switch (req->req_type) {
case DP_ENUM_PATH_RESOURCES:
case DP_POWER_DOWN_PHY:
case DP_POWER_UP_PHY:
buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
idx++;
break;
case DP_ALLOCATE_PAYLOAD:
buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
(req->u.allocate_payload.number_sdp_streams & 0xf);
idx++;
buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
idx++;
buf[idx] = (req->u.allocate_payload.pbn >> 8);
idx++;
buf[idx] = (req->u.allocate_payload.pbn & 0xff);
idx++;
for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
(req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
idx++;
}
if (req->u.allocate_payload.number_sdp_streams & 1) {
i = req->u.allocate_payload.number_sdp_streams - 1;
buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
idx++;
}
break;
case DP_QUERY_PAYLOAD:
buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
idx++;
buf[idx] = (req->u.query_payload.vcpi & 0x7f);
idx++;
break;
case DP_REMOTE_DPCD_READ:
buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
idx++;
buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
idx++;
buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
idx++;
buf[idx] = (req->u.dpcd_read.num_bytes);
idx++;
break;
case DP_REMOTE_DPCD_WRITE:
buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
idx++;
buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
idx++;
buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
idx++;
buf[idx] = (req->u.dpcd_write.num_bytes);
idx++;
memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
idx += req->u.dpcd_write.num_bytes;
break;
case DP_REMOTE_I2C_READ:
buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
idx++;
for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
idx++;
buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
idx++;
memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
idx += req->u.i2c_read.transactions[i].num_bytes;
buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4;
buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
idx++;
}
buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
idx++;
buf[idx] = (req->u.i2c_read.num_bytes_read);
idx++;
break;
case DP_REMOTE_I2C_WRITE:
buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
idx++;
buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
idx++;
buf[idx] = (req->u.i2c_write.num_bytes);
idx++;
memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
idx += req->u.i2c_write.num_bytes;
break;
}
raw->cur_len = idx;
}
EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req);
/* Decode a sideband request we've encoded, mainly used for debugging */
int
drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw,
struct drm_dp_sideband_msg_req_body *req)
{
const u8 *buf = raw->msg;
int i, idx = 0;
req->req_type = buf[idx++] & 0x7f;
switch (req->req_type) {
case DP_ENUM_PATH_RESOURCES:
case DP_POWER_DOWN_PHY:
case DP_POWER_UP_PHY:
req->u.port_num.port_number = (buf[idx] >> 4) & 0xf;
break;
case DP_ALLOCATE_PAYLOAD:
{
struct drm_dp_allocate_payload *a =
&req->u.allocate_payload;
a->number_sdp_streams = buf[idx] & 0xf;
a->port_number = (buf[idx] >> 4) & 0xf;
WARN_ON(buf[++idx] & 0x80);
a->vcpi = buf[idx] & 0x7f;
a->pbn = buf[++idx] << 8;
a->pbn |= buf[++idx];
idx++;
for (i = 0; i < a->number_sdp_streams; i++) {
a->sdp_stream_sink[i] =
(buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf;
}
}
break;
case DP_QUERY_PAYLOAD:
req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf;
WARN_ON(buf[++idx] & 0x80);
req->u.query_payload.vcpi = buf[idx] & 0x7f;
break;
case DP_REMOTE_DPCD_READ:
{
struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read;
r->port_number = (buf[idx] >> 4) & 0xf;
r->dpcd_address = (buf[idx] << 16) & 0xf0000;
r->dpcd_address |= (buf[++idx] << 8) & 0xff00;
r->dpcd_address |= buf[++idx] & 0xff;
r->num_bytes = buf[++idx];
}
break;
case DP_REMOTE_DPCD_WRITE:
{
struct drm_dp_remote_dpcd_write *w =
&req->u.dpcd_write;
w->port_number = (buf[idx] >> 4) & 0xf;
w->dpcd_address = (buf[idx] << 16) & 0xf0000;
w->dpcd_address |= (buf[++idx] << 8) & 0xff00;
w->dpcd_address |= buf[++idx] & 0xff;
w->num_bytes = buf[++idx];
w->bytes = kmemdup(&buf[++idx], w->num_bytes,
GFP_KERNEL);
if (!w->bytes)
return -ENOMEM;
}
break;
case DP_REMOTE_I2C_READ:
{
struct drm_dp_remote_i2c_read *r = &req->u.i2c_read;
struct drm_dp_remote_i2c_read_tx *tx;
bool failed = false;
r->num_transactions = buf[idx] & 0x3;
r->port_number = (buf[idx] >> 4) & 0xf;
for (i = 0; i < r->num_transactions; i++) {
tx = &r->transactions[i];
tx->i2c_dev_id = buf[++idx] & 0x7f;
tx->num_bytes = buf[++idx];
tx->bytes = kmemdup(&buf[++idx],
tx->num_bytes,
GFP_KERNEL);
if (!tx->bytes) {
failed = true;
break;
}
idx += tx->num_bytes;
tx->no_stop_bit = (buf[idx] >> 5) & 0x1;
tx->i2c_transaction_delay = buf[idx] & 0xf;
}
if (failed) {
for (i = 0; i < r->num_transactions; i++) {
tx = &r->transactions[i];
kfree(tx->bytes);
}
return -ENOMEM;
}
r->read_i2c_device_id = buf[++idx] & 0x7f;
r->num_bytes_read = buf[++idx];
}
break;
case DP_REMOTE_I2C_WRITE:
{
struct drm_dp_remote_i2c_write *w = &req->u.i2c_write;
w->port_number = (buf[idx] >> 4) & 0xf;
w->write_i2c_device_id = buf[++idx] & 0x7f;
w->num_bytes = buf[++idx];
w->bytes = kmemdup(&buf[++idx], w->num_bytes,
GFP_KERNEL);
if (!w->bytes)
return -ENOMEM;
}
break;
}
return 0;
}
EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req);
void
drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req,
int indent, struct drm_printer *printer)
{
int i;
#define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__)
if (req->req_type == DP_LINK_ADDRESS) {
/* No contents to print */
P("type=%s\n", drm_dp_mst_req_type_str(req->req_type));
return;
}
P("type=%s contents:\n", drm_dp_mst_req_type_str(req->req_type));
indent++;
switch (req->req_type) {
case DP_ENUM_PATH_RESOURCES:
case DP_POWER_DOWN_PHY:
case DP_POWER_UP_PHY:
P("port=%d\n", req->u.port_num.port_number);
break;
case DP_ALLOCATE_PAYLOAD:
P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n",
req->u.allocate_payload.port_number,
req->u.allocate_payload.vcpi, req->u.allocate_payload.pbn,
req->u.allocate_payload.number_sdp_streams,
req->u.allocate_payload.number_sdp_streams,
req->u.allocate_payload.sdp_stream_sink);
break;
case DP_QUERY_PAYLOAD:
P("port=%d vcpi=%d\n",
req->u.query_payload.port_number,
req->u.query_payload.vcpi);
break;
case DP_REMOTE_DPCD_READ:
P("port=%d dpcd_addr=%05x len=%d\n",
req->u.dpcd_read.port_number, req->u.dpcd_read.dpcd_address,
req->u.dpcd_read.num_bytes);
break;
case DP_REMOTE_DPCD_WRITE:
P("port=%d addr=%05x len=%d: %*ph\n",
req->u.dpcd_write.port_number,
req->u.dpcd_write.dpcd_address,
req->u.dpcd_write.num_bytes, req->u.dpcd_write.num_bytes,
req->u.dpcd_write.bytes);
break;
case DP_REMOTE_I2C_READ:
P("port=%d num_tx=%d id=%d size=%d:\n",
req->u.i2c_read.port_number,
req->u.i2c_read.num_transactions,
req->u.i2c_read.read_i2c_device_id,
req->u.i2c_read.num_bytes_read);
indent++;
for (i = 0; i < req->u.i2c_read.num_transactions; i++) {
const struct drm_dp_remote_i2c_read_tx *rtx =
&req->u.i2c_read.transactions[i];
P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n",
i, rtx->i2c_dev_id, rtx->num_bytes,
rtx->no_stop_bit, rtx->i2c_transaction_delay,
rtx->num_bytes, rtx->bytes);
}
break;
case DP_REMOTE_I2C_WRITE:
P("port=%d id=%d size=%d: %*ph\n",
req->u.i2c_write.port_number,
req->u.i2c_write.write_i2c_device_id,
req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes,
req->u.i2c_write.bytes);
break;
default:
P("???\n");
break;
}
#undef P
}
EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body);
static inline void
drm_dp_mst_dump_sideband_msg_tx(struct drm_printer *p,
const struct drm_dp_sideband_msg_tx *txmsg)
{
struct drm_dp_sideband_msg_req_body req;
char buf[64];
int ret;
int i;
drm_dp_mst_rad_to_str(txmsg->dst->rad, txmsg->dst->lct, buf,
sizeof(buf));
drm_printf(p, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n",
txmsg->cur_offset, txmsg->cur_len, txmsg->seqno,
drm_dp_mst_sideband_tx_state_str(txmsg->state),
txmsg->path_msg, buf);
ret = drm_dp_decode_sideband_req(txmsg, &req);
if (ret) {
drm_printf(p, "<failed to decode sideband req: %d>\n", ret);
return;
}
drm_dp_dump_sideband_msg_req_body(&req, 1, p);
switch (req.req_type) {
case DP_REMOTE_DPCD_WRITE:
kfree(req.u.dpcd_write.bytes);
break;
case DP_REMOTE_I2C_READ:
for (i = 0; i < req.u.i2c_read.num_transactions; i++)
kfree(req.u.i2c_read.transactions[i].bytes);
break;
case DP_REMOTE_I2C_WRITE:
kfree(req.u.i2c_write.bytes);
break;
}
}
static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
{
u8 crc4;
crc4 = drm_dp_msg_data_crc4(msg, len);
msg[len] = crc4;
}
static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
struct drm_dp_sideband_msg_tx *raw)
{
int idx = 0;
u8 *buf = raw->msg;
buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
raw->cur_len = idx;
}
/* this adds a chunk of msg to the builder to get the final msg */
static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
u8 *replybuf, u8 replybuflen, bool hdr)
{
int ret;
u8 crc4;
if (hdr) {
u8 hdrlen;
struct drm_dp_sideband_msg_hdr recv_hdr;
ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
if (ret == false) {
print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
return false;
}
/*
* ignore out-of-order messages or messages that are part of a
* failed transaction
*/
if (!recv_hdr.somt && !msg->have_somt)
return false;
/* get length contained in this portion */
msg->curchunk_len = recv_hdr.msg_len;
msg->curchunk_hdrlen = hdrlen;
/* we have already gotten an somt - don't bother parsing */
if (recv_hdr.somt && msg->have_somt)
return false;
if (recv_hdr.somt) {
memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
msg->have_somt = true;
}
if (recv_hdr.eomt)
msg->have_eomt = true;
/* copy the bytes for the remainder of this header chunk */
msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
} else {
memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
msg->curchunk_idx += replybuflen;
}
if (msg->curchunk_idx >= msg->curchunk_len) {
/* do CRC */
crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
/* copy chunk into bigger msg */
memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
msg->curlen += msg->curchunk_len - 1;
}
return true;
}
static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
int i;
memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
idx += 16;
repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
for (i = 0; i < repmsg->u.link_addr.nports; i++) {
if (raw->msg[idx] & 0x80)
repmsg->u.link_addr.ports[i].input_port = 1;
repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
if (repmsg->u.link_addr.ports[i].input_port == 0)
repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
idx++;
if (idx > raw->curlen)
goto fail_len;
if (repmsg->u.link_addr.ports[i].input_port == 0) {
repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
idx++;
if (idx > raw->curlen)
goto fail_len;
memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
idx += 16;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
idx++;
}
if (idx > raw->curlen)
goto fail_len;
}
return true;
fail_len:
DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
idx++;
if (idx > raw->curlen)
goto fail_len;
memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
return true;
fail_len:
DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
return true;
fail_len:
DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
idx++;
/* TODO check */
memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
return true;
fail_len:
DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1;
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
idx += 2;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
idx += 2;
if (idx > raw->curlen)
goto fail_len;
return true;
fail_len:
DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.allocate_payload.vcpi = raw->msg[idx];
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
idx += 2;
if (idx > raw->curlen)
goto fail_len;
return true;
fail_len:
DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
idx += 2;
if (idx > raw->curlen)
goto fail_len;
return true;
fail_len:
DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf;
idx++;
if (idx > raw->curlen) {
DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
idx, raw->curlen);
return false;
}
return true;
}
static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *msg)
{
memset(msg, 0, sizeof(*msg));
msg->reply_type = (raw->msg[0] & 0x80) >> 7;
msg->req_type = (raw->msg[0] & 0x7f);
if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) {
memcpy(msg->u.nak.guid, &raw->msg[1], 16);
msg->u.nak.reason = raw->msg[17];
msg->u.nak.nak_data = raw->msg[18];
return false;
}
switch (msg->req_type) {
case DP_LINK_ADDRESS:
return drm_dp_sideband_parse_link_address(raw, msg);
case DP_QUERY_PAYLOAD:
return drm_dp_sideband_parse_query_payload_ack(raw, msg);
case DP_REMOTE_DPCD_READ:
return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
case DP_REMOTE_DPCD_WRITE:
return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
case DP_REMOTE_I2C_READ:
return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
case DP_ENUM_PATH_RESOURCES:
return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
case DP_ALLOCATE_PAYLOAD:
return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
case DP_POWER_DOWN_PHY:
case DP_POWER_UP_PHY:
return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
case DP_CLEAR_PAYLOAD_ID_TABLE:
return true; /* since there's nothing to parse */
default:
DRM_ERROR("Got unknown reply 0x%02x (%s)\n", msg->req_type,
drm_dp_mst_req_type_str(msg->req_type));
return false;
}
}
static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_req_body *msg)
{
int idx = 1;
msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
idx++;
if (idx > raw->curlen)
goto fail_len;
memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
idx += 16;
if (idx > raw->curlen)
goto fail_len;
msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
idx++;
return true;
fail_len:
DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_req_body *msg)
{
int idx = 1;
msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
idx++;
if (idx > raw->curlen)
goto fail_len;
memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
idx += 16;
if (idx > raw->curlen)
goto fail_len;
msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
idx++;
return true;
fail_len:
DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_req_body *msg)
{
memset(msg, 0, sizeof(*msg));
msg->req_type = (raw->msg[0] & 0x7f);
switch (msg->req_type) {
case DP_CONNECTION_STATUS_NOTIFY:
return drm_dp_sideband_parse_connection_status_notify(raw, msg);
case DP_RESOURCE_STATUS_NOTIFY:
return drm_dp_sideband_parse_resource_status_notify(raw, msg);
default:
DRM_ERROR("Got unknown request 0x%02x (%s)\n", msg->req_type,
drm_dp_mst_req_type_str(msg->req_type));
return false;
}
}
static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_REMOTE_DPCD_WRITE;
req.u.dpcd_write.port_number = port_num;
req.u.dpcd_write.dpcd_address = offset;
req.u.dpcd_write.num_bytes = num_bytes;
req.u.dpcd_write.bytes = bytes;
drm_dp_encode_sideband_req(&req, msg);
return 0;
}
static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_LINK_ADDRESS;
drm_dp_encode_sideband_req(&req, msg);
return 0;
}
static int build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE;
drm_dp_encode_sideband_req(&req, msg);
return 0;
}
static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_ENUM_PATH_RESOURCES;
req.u.port_num.port_number = port_num;
drm_dp_encode_sideband_req(&req, msg);
msg->path_msg = true;
return 0;
}
static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
u8 vcpi, uint16_t pbn,
u8 number_sdp_streams,
u8 *sdp_stream_sink)
{
struct drm_dp_sideband_msg_req_body req;
memset(&req, 0, sizeof(req));
req.req_type = DP_ALLOCATE_PAYLOAD;
req.u.allocate_payload.port_number = port_num;
req.u.allocate_payload.vcpi = vcpi;
req.u.allocate_payload.pbn = pbn;
req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
number_sdp_streams);
drm_dp_encode_sideband_req(&req, msg);
msg->path_msg = true;
return 0;
}
static int build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
int port_num, bool power_up)
{
struct drm_dp_sideband_msg_req_body req;
if (power_up)
req.req_type = DP_POWER_UP_PHY;
else
req.req_type = DP_POWER_DOWN_PHY;
req.u.port_num.port_number = port_num;
drm_dp_encode_sideband_req(&req, msg);
msg->path_msg = true;
return 0;
}
static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_vcpi *vcpi)
{
int ret, vcpi_ret;
mutex_lock(&mgr->payload_lock);
ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
if (ret > mgr->max_payloads) {
ret = -EINVAL;
DRM_DEBUG_KMS("out of payload ids %d\n", ret);
goto out_unlock;
}
vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
if (vcpi_ret > mgr->max_payloads) {
ret = -EINVAL;
DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
goto out_unlock;
}
set_bit(ret, &mgr->payload_mask);
set_bit(vcpi_ret, &mgr->vcpi_mask);
vcpi->vcpi = vcpi_ret + 1;
mgr->proposed_vcpis[ret - 1] = vcpi;
out_unlock:
mutex_unlock(&mgr->payload_lock);
return ret;
}
static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
int vcpi)
{
int i;
if (vcpi == 0)
return;
mutex_lock(&mgr->payload_lock);
DRM_DEBUG_KMS("putting payload %d\n", vcpi);
clear_bit(vcpi - 1, &mgr->vcpi_mask);
for (i = 0; i < mgr->max_payloads; i++) {
if (mgr->proposed_vcpis[i] &&
mgr->proposed_vcpis[i]->vcpi == vcpi) {
mgr->proposed_vcpis[i] = NULL;
clear_bit(i + 1, &mgr->payload_mask);
}
}
mutex_unlock(&mgr->payload_lock);
}
static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_sideband_msg_tx *txmsg)
{
unsigned int state;
/*
* All updates to txmsg->state are protected by mgr->qlock, and the two
* cases we check here are terminal states. For those the barriers
* provided by the wake_up/wait_event pair are enough.
*/
state = READ_ONCE(txmsg->state);
return (state == DRM_DP_SIDEBAND_TX_RX ||
state == DRM_DP_SIDEBAND_TX_TIMEOUT);
}
static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
struct drm_dp_sideband_msg_tx *txmsg)
{
struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
int ret;
ret = wait_event_timeout(mgr->tx_waitq,
check_txmsg_state(mgr, txmsg),
(4 * HZ));
mutex_lock(&mstb->mgr->qlock);
if (ret > 0) {
if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
ret = -EIO;
goto out;
}
} else {
DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
/* dump some state */
ret = -EIO;
/* remove from q */
if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
list_del(&txmsg->next);
}
if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
mstb->tx_slots[txmsg->seqno] = NULL;
}
mgr->is_waiting_for_dwn_reply = false;
}
out:
if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) {
struct drm_printer p = drm_debug_printer(DBG_PREFIX);
drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
}
mutex_unlock(&mgr->qlock);
drm_dp_mst_kick_tx(mgr);
return ret;
}
static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
{
struct drm_dp_mst_branch *mstb;
mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
if (!mstb)
return NULL;
mstb->lct = lct;
if (lct > 1)
memcpy(mstb->rad, rad, lct / 2);
INIT_LIST_HEAD(&mstb->ports);
kref_init(&mstb->topology_kref);
kref_init(&mstb->malloc_kref);
return mstb;
}
static void drm_dp_free_mst_branch_device(struct kref *kref)
{
struct drm_dp_mst_branch *mstb =
container_of(kref, struct drm_dp_mst_branch, malloc_kref);
if (mstb->port_parent)
drm_dp_mst_put_port_malloc(mstb->port_parent);
kfree(mstb);
}
/**
* DOC: Branch device and port refcounting
*
* Topology refcount overview
* ~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* The refcounting schemes for &struct drm_dp_mst_branch and &struct
* drm_dp_mst_port are somewhat unusual. Both ports and branch devices have
* two different kinds of refcounts: topology refcounts, and malloc refcounts.
*
* Topology refcounts are not exposed to drivers, and are handled internally
* by the DP MST helpers. The helpers use them in order to prevent the
* in-memory topology state from being changed in the middle of critical
* operations like changing the internal state of payload allocations. This
* means each branch and port will be considered to be connected to the rest
* of the topology until its topology refcount reaches zero. Additionally,
* for ports this means that their associated &struct drm_connector will stay
* registered with userspace until the port's refcount reaches 0.
*
* Malloc refcount overview
* ~~~~~~~~~~~~~~~~~~~~~~~~
*
* Malloc references are used to keep a &struct drm_dp_mst_port or &struct
* drm_dp_mst_branch allocated even after all of its topology references have
* been dropped, so that the driver or MST helpers can safely access each
* branch's last known state before it was disconnected from the topology.
* When the malloc refcount of a port or branch reaches 0, the memory
* allocation containing the &struct drm_dp_mst_branch or &struct
* drm_dp_mst_port respectively will be freed.
*
* For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed
* to drivers. As of writing this documentation, there are no drivers that
* have a usecase for accessing &struct drm_dp_mst_branch outside of the MST
* helpers. Exposing this API to drivers in a race-free manner would take more
* tweaking of the refcounting scheme, however patches are welcome provided
* there is a legitimate driver usecase for this.
*
* Refcount relationships in a topology
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* Let's take a look at why the relationship between topology and malloc
* refcounts is designed the way it is.
*
* .. kernel-figure:: dp-mst/topology-figure-1.dot
*
* An example of topology and malloc refs in a DP MST topology with two
* active payloads. Topology refcount increments are indicated by solid
* lines, and malloc refcount increments are indicated by dashed lines.
* Each starts from the branch which incremented the refcount, and ends at
* the branch to which the refcount belongs to, i.e. the arrow points the
* same way as the C pointers used to reference a structure.
*
* As you can see in the above figure, every branch increments the topology
* refcount of its children, and increments the malloc refcount of its
* parent. Additionally, every payload increments the malloc refcount of its
* assigned port by 1.
*
* So, what would happen if MSTB #3 from the above figure was unplugged from
* the system, but the driver hadn't yet removed payload #2 from port #3? The
* topology would start to look like the figure below.
*
* .. kernel-figure:: dp-mst/topology-figure-2.dot
*
* Ports and branch devices which have been released from memory are
* colored grey, and references which have been removed are colored red.
*
* Whenever a port or branch device's topology refcount reaches zero, it will
* decrement the topology refcounts of all its children, the malloc refcount
* of its parent, and finally its own malloc refcount. For MSTB #4 and port
* #4, this means they both have been disconnected from the topology and freed
* from memory. But, because payload #2 is still holding a reference to port
* #3, port #3 is removed from the topology but its &struct drm_dp_mst_port
* is still accessible from memory. This also means port #3 has not yet
* decremented the malloc refcount of MSTB #3, so its &struct
* drm_dp_mst_branch will also stay allocated in memory until port #3's
* malloc refcount reaches 0.
*
* This relationship is necessary because in order to release payload #2, we
* need to be able to figure out the last relative of port #3 that's still
* connected to the topology. In this case, we would travel up the topology as
* shown below.
*
* .. kernel-figure:: dp-mst/topology-figure-3.dot
*
* And finally, remove payload #2 by communicating with port #2 through
* sideband transactions.
*/
/**
* drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch
* device
* @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of
*
* Increments &drm_dp_mst_branch.malloc_kref. When
* &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
* will be released and @mstb may no longer be used.
*
* See also: drm_dp_mst_put_mstb_malloc()
*/
static void
drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb)
{
kref_get(&mstb->malloc_kref);
DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref));
}
/**
* drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch
* device
* @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of
*
* Decrements &drm_dp_mst_branch.malloc_kref. When
* &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
* will be released and @mstb may no longer be used.
*
* See also: drm_dp_mst_get_mstb_malloc()
*/
static void
drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb)
{
DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1);
kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device);
}
static void drm_dp_free_mst_port(struct kref *kref)
{
struct drm_dp_mst_port *port =
container_of(kref, struct drm_dp_mst_port, malloc_kref);
drm_dp_mst_put_mstb_malloc(port->parent);
kfree(port);
}
/**
* drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port
* @port: The &struct drm_dp_mst_port to increment the malloc refcount of
*
* Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
* reaches 0, the memory allocation for @port will be released and @port may
* no longer be used.
*
* Because @port could potentially be freed at any time by the DP MST helpers
* if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this
* function, drivers that which to make use of &struct drm_dp_mst_port should
* ensure that they grab at least one main malloc reference to their MST ports
* in &drm_dp_mst_topology_cbs.add_connector. This callback is called before
* there is any chance for &drm_dp_mst_port.malloc_kref to reach 0.
*
* See also: drm_dp_mst_put_port_malloc()
*/
void
drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port)
{
kref_get(&port->malloc_kref);
DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref));
}
EXPORT_SYMBOL(drm_dp_mst_get_port_malloc);
/**
* drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port
* @port: The &struct drm_dp_mst_port to decrement the malloc refcount of
*
* Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
* reaches 0, the memory allocation for @port will be released and @port may
* no longer be used.
*
* See also: drm_dp_mst_get_port_malloc()
*/
void
drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port)
{
DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1);
kref_put(&port->malloc_kref, drm_dp_free_mst_port);
}
EXPORT_SYMBOL(drm_dp_mst_put_port_malloc);
#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
#define STACK_DEPTH 8
static noinline void
__topology_ref_save(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_topology_ref_history *history,
enum drm_dp_mst_topology_ref_type type)
{
struct drm_dp_mst_topology_ref_entry *entry = NULL;
depot_stack_handle_t backtrace;
ulong stack_entries[STACK_DEPTH];
uint n;
int i;
n = stack_trace_save(stack_entries, ARRAY_SIZE(stack_entries), 1);
backtrace = stack_depot_save(stack_entries, n, GFP_KERNEL);
if (!backtrace)
return;
/* Try to find an existing entry for this backtrace */
for (i = 0; i < history->len; i++) {
if (history->entries[i].backtrace == backtrace) {
entry = &history->entries[i];
break;
}
}
/* Otherwise add one */
if (!entry) {
struct drm_dp_mst_topology_ref_entry *new;
int new_len = history->len + 1;
new = krealloc(history->entries, sizeof(*new) * new_len,
GFP_KERNEL);
if (!new)
return;
entry = &new[history->len];
history->len = new_len;
history->entries = new;
entry->backtrace = backtrace;
entry->type = type;
entry->count = 0;
}
entry->count++;
entry->ts_nsec = ktime_get_ns();
}
static int
topology_ref_history_cmp(const void *a, const void *b)
{
const struct drm_dp_mst_topology_ref_entry *entry_a = a, *entry_b = b;
if (entry_a->ts_nsec > entry_b->ts_nsec)
return 1;
else if (entry_a->ts_nsec < entry_b->ts_nsec)
return -1;
else
return 0;
}
static inline const char *
topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type)
{
if (type == DRM_DP_MST_TOPOLOGY_REF_GET)
return "get";
else
return "put";
}
static void
__dump_topology_ref_history(struct drm_dp_mst_topology_ref_history *history,
void *ptr, const char *type_str)
{
struct drm_printer p = drm_debug_printer(DBG_PREFIX);
char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
int i;
if (!buf)
return;
if (!history->len)
goto out;
/* First, sort the list so that it goes from oldest to newest
* reference entry
*/
sort(history->entries, history->len, sizeof(*history->entries),
topology_ref_history_cmp, NULL);
drm_printf(&p, "%s (%p) topology count reached 0, dumping history:\n",
type_str, ptr);
for (i = 0; i < history->len; i++) {
const struct drm_dp_mst_topology_ref_entry *entry =
&history->entries[i];
ulong *entries;
uint nr_entries;
u64 ts_nsec = entry->ts_nsec;
u32 rem_nsec = do_div(ts_nsec, 1000000000);
nr_entries = stack_depot_fetch(entry->backtrace, &entries);
stack_trace_snprint(buf, PAGE_SIZE, entries, nr_entries, 4);
drm_printf(&p, " %d %ss (last at %5llu.%06u):\n%s",
entry->count,
topology_ref_type_to_str(entry->type),
ts_nsec, rem_nsec / 1000, buf);
}
/* Now free the history, since this is the only time we expose it */
kfree(history->entries);
out:
kfree(buf);
}
static __always_inline void
drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb)
{
__dump_topology_ref_history(&mstb->topology_ref_history, mstb,
"MSTB");
}
static __always_inline void
drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port)
{
__dump_topology_ref_history(&port->topology_ref_history, port,
"Port");
}
static __always_inline void
save_mstb_topology_ref(struct drm_dp_mst_branch *mstb,
enum drm_dp_mst_topology_ref_type type)
{
__topology_ref_save(mstb->mgr, &mstb->topology_ref_history, type);
}
static __always_inline void
save_port_topology_ref(struct drm_dp_mst_port *port,
enum drm_dp_mst_topology_ref_type type)
{
__topology_ref_save(port->mgr, &port->topology_ref_history, type);
}
static inline void
topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr)
{
mutex_lock(&mgr->topology_ref_history_lock);
}
static inline void
topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr)
{
mutex_unlock(&mgr->topology_ref_history_lock);
}
#else
static inline void
topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) {}
static inline void
topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) {}
static inline void
drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) {}
static inline void
drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) {}
#define save_mstb_topology_ref(mstb, type)
#define save_port_topology_ref(port, type)
#endif
static void drm_dp_destroy_mst_branch_device(struct kref *kref)
{
struct drm_dp_mst_branch *mstb =
container_of(kref, struct drm_dp_mst_branch, topology_kref);
struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
drm_dp_mst_dump_mstb_topology_history(mstb);
INIT_LIST_HEAD(&mstb->destroy_next);
/*
* This can get called under mgr->mutex, so we need to perform the
* actual destruction of the mstb in another worker
*/
mutex_lock(&mgr->delayed_destroy_lock);
list_add(&mstb->destroy_next, &mgr->destroy_branch_device_list);
mutex_unlock(&mgr->delayed_destroy_lock);
schedule_work(&mgr->delayed_destroy_work);
}
/**
* drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
* branch device unless it's zero
* @mstb: &struct drm_dp_mst_branch to increment the topology refcount of
*
* Attempts to grab a topology reference to @mstb, if it hasn't yet been
* removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has
* reached 0). Holding a topology reference implies that a malloc reference
* will be held to @mstb as long as the user holds the topology reference.
*
* Care should be taken to ensure that the user has at least one malloc
* reference to @mstb. If you already have a topology reference to @mstb, you
* should use drm_dp_mst_topology_get_mstb() instead.
*
* See also:
* drm_dp_mst_topology_get_mstb()
* drm_dp_mst_topology_put_mstb()
*
* Returns:
* * 1: A topology reference was grabbed successfully
* * 0: @port is no longer in the topology, no reference was grabbed
*/
static int __must_check
drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb)
{
int ret;
topology_ref_history_lock(mstb->mgr);
ret = kref_get_unless_zero(&mstb->topology_kref);
if (ret) {
DRM_DEBUG("mstb %p (%d)\n",
mstb, kref_read(&mstb->topology_kref));
save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
}
topology_ref_history_unlock(mstb->mgr);
return ret;
}
/**
* drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a
* branch device
* @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of
*
* Increments &drm_dp_mst_branch.topology_refcount without checking whether or
* not it's already reached 0. This is only valid to use in scenarios where
* you are already guaranteed to have at least one active topology reference
* to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used.
*
* See also:
* drm_dp_mst_topology_try_get_mstb()
* drm_dp_mst_topology_put_mstb()
*/
static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb)
{
topology_ref_history_lock(mstb->mgr);
save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
WARN_ON(kref_read(&mstb->topology_kref) == 0);
kref_get(&mstb->topology_kref);
DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
topology_ref_history_unlock(mstb->mgr);
}
/**
* drm_dp_mst_topology_put_mstb() - release a topology reference to a branch
* device
* @mstb: The &struct drm_dp_mst_branch to release the topology reference from
*
* Releases a topology reference from @mstb by decrementing
* &drm_dp_mst_branch.topology_kref.
*
* See also:
* drm_dp_mst_topology_try_get_mstb()
* drm_dp_mst_topology_get_mstb()
*/
static void
drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb)
{
topology_ref_history_lock(mstb->mgr);
DRM_DEBUG("mstb %p (%d)\n",
mstb, kref_read(&mstb->topology_kref) - 1);
save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_PUT);
topology_ref_history_unlock(mstb->mgr);
kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device);
}
static void drm_dp_destroy_port(struct kref *kref)
{
struct drm_dp_mst_port *port =
container_of(kref, struct drm_dp_mst_port, topology_kref);
struct drm_dp_mst_topology_mgr *mgr = port->mgr;
drm_dp_mst_dump_port_topology_history(port);
/* There's nothing that needs locking to destroy an input port yet */
if (port->input) {
drm_dp_mst_put_port_malloc(port);
return;
}
kfree(port->cached_edid);
/*
* we can't destroy the connector here, as we might be holding the
* mode_config.mutex from an EDID retrieval
*/
mutex_lock(&mgr->delayed_destroy_lock);
list_add(&port->next, &mgr->destroy_port_list);
mutex_unlock(&mgr->delayed_destroy_lock);
schedule_work(&mgr->delayed_destroy_work);
}
/**
* drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a
* port unless it's zero
* @port: &struct drm_dp_mst_port to increment the topology refcount of
*
* Attempts to grab a topology reference to @port, if it hasn't yet been
* removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached
* 0). Holding a topology reference implies that a malloc reference will be
* held to @port as long as the user holds the topology reference.
*
* Care should be taken to ensure that the user has at least one malloc
* reference to @port. If you already have a topology reference to @port, you
* should use drm_dp_mst_topology_get_port() instead.
*
* See also:
* drm_dp_mst_topology_get_port()
* drm_dp_mst_topology_put_port()
*
* Returns:
* * 1: A topology reference was grabbed successfully
* * 0: @port is no longer in the topology, no reference was grabbed
*/
static int __must_check
drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port)
{
int ret;
topology_ref_history_lock(port->mgr);
ret = kref_get_unless_zero(&port->topology_kref);
if (ret) {
DRM_DEBUG("port %p (%d)\n",
port, kref_read(&port->topology_kref));
save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
}
topology_ref_history_unlock(port->mgr);
return ret;
}
/**
* drm_dp_mst_topology_get_port() - Increment the topology refcount of a port
* @port: The &struct drm_dp_mst_port to increment the topology refcount of
*
* Increments &drm_dp_mst_port.topology_refcount without checking whether or
* not it's already reached 0. This is only valid to use in scenarios where
* you are already guaranteed to have at least one active topology reference
* to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used.
*
* See also:
* drm_dp_mst_topology_try_get_port()
* drm_dp_mst_topology_put_port()
*/
static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port)
{
topology_ref_history_lock(port->mgr);
WARN_ON(kref_read(&port->topology_kref) == 0);
kref_get(&port->topology_kref);
DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->topology_kref));
save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
topology_ref_history_unlock(port->mgr);
}
/**
* drm_dp_mst_topology_put_port() - release a topology reference to a port
* @port: The &struct drm_dp_mst_port to release the topology reference from
*
* Releases a topology reference from @port by decrementing
* &drm_dp_mst_port.topology_kref.
*
* See also:
* drm_dp_mst_topology_try_get_port()
* drm_dp_mst_topology_get_port()
*/
static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port)
{
topology_ref_history_lock(port->mgr);
DRM_DEBUG("port %p (%d)\n",
port, kref_read(&port->topology_kref) - 1);
save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_PUT);
topology_ref_history_unlock(port->mgr);
kref_put(&port->topology_kref, drm_dp_destroy_port);
}
static struct drm_dp_mst_branch *
drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_branch *to_find)
{
struct drm_dp_mst_port *port;
struct drm_dp_mst_branch *rmstb;
if (to_find == mstb)
return mstb;
list_for_each_entry(port, &mstb->ports, next) {
if (port->mstb) {
rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
port->mstb, to_find);
if (rmstb)
return rmstb;
}
}
return NULL;
}
static struct drm_dp_mst_branch *
drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb)
{
struct drm_dp_mst_branch *rmstb = NULL;
mutex_lock(&mgr->lock);
if (mgr->mst_primary) {
rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
mgr->mst_primary, mstb);
if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb))
rmstb = NULL;
}
mutex_unlock(&mgr->lock);
return rmstb;
}
static struct drm_dp_mst_port *
drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_port *to_find)
{
struct drm_dp_mst_port *port, *mport;
list_for_each_entry(port, &mstb->ports, next) {
if (port == to_find)
return port;
if (port->mstb) {
mport = drm_dp_mst_topology_get_port_validated_locked(
port->mstb, to_find);
if (mport)
return mport;
}
}
return NULL;
}
static struct drm_dp_mst_port *
drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port)
{
struct drm_dp_mst_port *rport = NULL;
mutex_lock(&mgr->lock);
if (mgr->mst_primary) {
rport = drm_dp_mst_topology_get_port_validated_locked(
mgr->mst_primary, port);
if (rport && !drm_dp_mst_topology_try_get_port(rport))
rport = NULL;
}
mutex_unlock(&mgr->lock);
return rport;
}
static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
{
struct drm_dp_mst_port *port;
int ret;
list_for_each_entry(port, &mstb->ports, next) {
if (port->port_num == port_num) {
ret = drm_dp_mst_topology_try_get_port(port);
return ret ? port : NULL;
}
}
return NULL;
}
/*
* calculate a new RAD for this MST branch device
* if parent has an LCT of 2 then it has 1 nibble of RAD,
* if parent has an LCT of 3 then it has 2 nibbles of RAD,
*/
static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
u8 *rad)
{
int parent_lct = port->parent->lct;
int shift = 4;
int idx = (parent_lct - 1) / 2;
if (parent_lct > 1) {
memcpy(rad, port->parent->rad, idx + 1);
shift = (parent_lct % 2) ? 4 : 0;
} else
rad[0] = 0;
rad[idx] |= port->port_num << shift;
return parent_lct + 1;
}
static bool drm_dp_mst_is_end_device(u8 pdt, bool mcs)
{
switch (pdt) {
case DP_PEER_DEVICE_DP_LEGACY_CONV:
case DP_PEER_DEVICE_SST_SINK:
return true;
case DP_PEER_DEVICE_MST_BRANCHING:
/* For sst branch device */
if (!mcs)
return true;
return false;
}
return true;
}
static int
drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
bool new_mcs)
{
struct drm_dp_mst_topology_mgr *mgr = port->mgr;
struct drm_dp_mst_branch *mstb;
u8 rad[8], lct;
int ret = 0;
if (port->pdt == new_pdt && port->mcs == new_mcs)
return 0;
/* Teardown the old pdt, if there is one */
if (port->pdt != DP_PEER_DEVICE_NONE) {
if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
/*
* If the new PDT would also have an i2c bus,
* don't bother with reregistering it
*/
if (new_pdt != DP_PEER_DEVICE_NONE &&
drm_dp_mst_is_end_device(new_pdt, new_mcs)) {
port->pdt = new_pdt;
port->mcs = new_mcs;
return 0;
}
/* remove i2c over sideband */
drm_dp_mst_unregister_i2c_bus(&port->aux);
} else {
mutex_lock(&mgr->lock);
drm_dp_mst_topology_put_mstb(port->mstb);
port->mstb = NULL;
mutex_unlock(&mgr->lock);
}
}
port->pdt = new_pdt;
port->mcs = new_mcs;
if (port->pdt != DP_PEER_DEVICE_NONE) {
if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
/* add i2c over sideband */
ret = drm_dp_mst_register_i2c_bus(&port->aux);
} else {
lct = drm_dp_calculate_rad(port, rad);
mstb = drm_dp_add_mst_branch_device(lct, rad);
if (!mstb) {
ret = -ENOMEM;
DRM_ERROR("Failed to create MSTB for port %p",
port);
goto out;
}
mutex_lock(&mgr->lock);
port->mstb = mstb;
mstb->mgr = port->mgr;
mstb->port_parent = port;
/*
* Make sure this port's memory allocation stays
* around until its child MSTB releases it
*/
drm_dp_mst_get_port_malloc(port);
mutex_unlock(&mgr->lock);
/* And make sure we send a link address for this */
ret = 1;
}
}
out:
if (ret < 0)
port->pdt = DP_PEER_DEVICE_NONE;
return ret;
}
/**
* drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband
* @aux: Fake sideband AUX CH
* @offset: address of the (first) register to read
* @buffer: buffer to store the register values
* @size: number of bytes in @buffer
*
* Performs the same functionality for remote devices via
* sideband messaging as drm_dp_dpcd_read() does for local
* devices via actual AUX CH.
*
* Return: Number of bytes read, or negative error code on failure.
*/
ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
unsigned int offset, void *buffer, size_t size)
{
struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
aux);
return drm_dp_send_dpcd_read(port->mgr, port,
offset, size, buffer);
}
/**
* drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband
* @aux: Fake sideband AUX CH
* @offset: address of the (first) register to write
* @buffer: buffer containing the values to write
* @size: number of bytes in @buffer
*
* Performs the same functionality for remote devices via
* sideband messaging as drm_dp_dpcd_write() does for local
* devices via actual AUX CH.
*
* Return: 0 on success, negative error code on failure.
*/
ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
unsigned int offset, void *buffer, size_t size)
{
struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
aux);
return drm_dp_send_dpcd_write(port->mgr, port,
offset, size, buffer);
}
static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
{
int ret;
memcpy(mstb->guid, guid, 16);
if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
if (mstb->port_parent) {
ret = drm_dp_send_dpcd_write(
mstb->mgr,
mstb->port_parent,
DP_GUID,
16,
mstb->guid);
} else {
ret = drm_dp_dpcd_write(
mstb->mgr->aux,
DP_GUID,
mstb->guid,
16);
}
}
}
static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
int pnum,
char *proppath,
size_t proppath_size)
{
int i;
char temp[8];
snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
for (i = 0; i < (mstb->lct - 1); i++) {
int shift = (i % 2) ? 0 : 4;
int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
snprintf(temp, sizeof(temp), "-%d", port_num);
strlcat(proppath, temp, proppath_size);
}
snprintf(temp, sizeof(temp), "-%d", pnum);
strlcat(proppath, temp, proppath_size);
}
/**
* drm_dp_mst_connector_late_register() - Late MST connector registration
* @connector: The MST connector
* @port: The MST port for this connector
*
* Helper to register the remote aux device for this MST port. Drivers should
* call this from their mst connector's late_register hook to enable MST aux
* devices.
*
* Return: 0 on success, negative error code on failure.
*/
int drm_dp_mst_connector_late_register(struct drm_connector *connector,
struct drm_dp_mst_port *port)
{
DRM_DEBUG_KMS("registering %s remote bus for %s\n",
port->aux.name, connector->kdev->kobj.name);
port->aux.dev = connector->kdev;
return drm_dp_aux_register_devnode(&port->aux);
}
EXPORT_SYMBOL(drm_dp_mst_connector_late_register);
/**
* drm_dp_mst_connector_early_unregister() - Early MST connector unregistration
* @connector: The MST connector
* @port: The MST port for this connector
*
* Helper to unregister the remote aux device for this MST port, registered by
* drm_dp_mst_connector_late_register(). Drivers should call this from their mst
* connector's early_unregister hook.
*/
void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
struct drm_dp_mst_port *port)
{
DRM_DEBUG_KMS("unregistering %s remote bus for %s\n",
port->aux.name, connector->kdev->kobj.name);
drm_dp_aux_unregister_devnode(&port->aux);
}
EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister);
static void
drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_port *port)
{
struct drm_dp_mst_topology_mgr *mgr = port->mgr;
char proppath[255];
int ret;
build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
port->connector = mgr->cbs->add_connector(mgr, port, proppath);
if (!port->connector) {
ret = -ENOMEM;
goto error;
}
if (port->pdt != DP_PEER_DEVICE_NONE &&
drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
port->cached_edid = drm_get_edid(port->connector,
&port->aux.ddc);
drm_connector_set_tile_property(port->connector);
}
mgr->cbs->register_connector(port->connector);
return;
error:
DRM_ERROR("Failed to create connector for port %p: %d\n", port, ret);
}
/*
* Drop a topology reference, and unlink the port from the in-memory topology
* layout
*/
static void
drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port)
{
mutex_lock(&mgr->lock);
port->parent->num_ports--;
list_del(&port->next);
mutex_unlock(&mgr->lock);
drm_dp_mst_topology_put_port(port);
}
static struct drm_dp_mst_port *
drm_dp_mst_add_port(struct drm_device *dev,
struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb, u8 port_number)
{
struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL);
if (!port)
return NULL;
kref_init(&port->topology_kref);
kref_init(&port->malloc_kref);
port->parent = mstb;
port->port_num = port_number;
port->mgr = mgr;
port->aux.name = "DPMST";
port->aux.dev = dev->dev;
port->aux.is_remote = true;
/* initialize the MST downstream port's AUX crc work queue */
drm_dp_remote_aux_init(&port->aux);
/*
* Make sure the memory allocation for our parent branch stays
* around until our own memory allocation is released
*/
drm_dp_mst_get_mstb_malloc(mstb);
return port;
}
static int
drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
struct drm_device *dev,
struct drm_dp_link_addr_reply_port *port_msg)
{
struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
struct drm_dp_mst_port *port;
int old_ddps = 0, ret;
u8 new_pdt = DP_PEER_DEVICE_NONE;
bool new_mcs = 0;
bool created = false, send_link_addr = false, changed = false;
port = drm_dp_get_port(mstb, port_msg->port_number);
if (!port) {
port = drm_dp_mst_add_port(dev, mgr, mstb,
port_msg->port_number);
if (!port)
return -ENOMEM;
created = true;
changed = true;
} else if (!port->input && port_msg->input_port && port->connector) {
/* Since port->connector can't be changed here, we create a
* new port if input_port changes from 0 to 1
*/
drm_dp_mst_topology_unlink_port(mgr, port);
drm_dp_mst_topology_put_port(port);
port = drm_dp_mst_add_port(dev, mgr, mstb,
port_msg->port_number);
if (!port)
return -ENOMEM;
changed = true;
created = true;
} else if (port->input && !port_msg->input_port) {
changed = true;
} else if (port->connector) {
/* We're updating a port that's exposed to userspace, so do it
* under lock
*/
drm_modeset_lock(&mgr->base.lock, NULL);
old_ddps = port->ddps;
changed = port->ddps != port_msg->ddps ||
(port->ddps &&
(port->ldps != port_msg->legacy_device_plug_status ||
port->dpcd_rev != port_msg->dpcd_revision ||
port->mcs != port_msg->mcs ||
port->pdt != port_msg->peer_device_type ||
port->num_sdp_stream_sinks !=
port_msg->num_sdp_stream_sinks));
}
port->input = port_msg->input_port;
if (!port->input)
new_pdt = port_msg->peer_device_type;
new_mcs = port_msg->mcs;
port->ddps = port_msg->ddps;
port->ldps = port_msg->legacy_device_plug_status;
port->dpcd_rev = port_msg->dpcd_revision;
port->num_sdp_streams = port_msg->num_sdp_streams;
port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
/* manage mstb port lists with mgr lock - take a reference
for this list */
if (created) {
mutex_lock(&mgr->lock);
drm_dp_mst_topology_get_port(port);
list_add(&port->next, &mstb->ports);
mstb->num_ports++;
mutex_unlock(&mgr->lock);
}
if (old_ddps != port->ddps) {
if (port->ddps) {
if (!port->input) {
drm_dp_send_enum_path_resources(mgr, mstb,
port);
}
} else {
port->available_pbn = 0;
}
}
ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
if (ret == 1) {
send_link_addr = true;
} else if (ret < 0) {
DRM_ERROR("Failed to change PDT on port %p: %d\n",
port, ret);
goto fail;
}
/*
* If this port wasn't just created, then we're reprobing because
* we're coming out of suspend. In this case, always resend the link
* address if there's an MSTB on this port
*/
if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
port->mcs)
send_link_addr = true;
if (port->connector)
drm_modeset_unlock(&mgr->base.lock);
else if (!port->input)
drm_dp_mst_port_add_connector(mstb, port);
if (send_link_addr && port->mstb) {
ret = drm_dp_send_link_address(mgr, port->mstb);
if (ret == 1) /* MSTB below us changed */
changed = true;
else if (ret < 0)
goto fail_put;
}
/* put reference to this port */
drm_dp_mst_topology_put_port(port);
return changed;
fail:
drm_dp_mst_topology_unlink_port(mgr, port);
if (port->connector)
drm_modeset_unlock(&mgr->base.lock);
fail_put:
drm_dp_mst_topology_put_port(port);
return ret;
}
static void
drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
struct drm_dp_connection_status_notify *conn_stat)
{
struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
struct drm_dp_mst_port *port;
int old_ddps, old_input, ret, i;
u8 new_pdt;
bool new_mcs;
bool dowork = false, create_connector = false;
port = drm_dp_get_port(mstb, conn_stat->port_number);
if (!port)
return;
if (port->connector) {
if (!port->input && conn_stat->input_port) {
/*
* We can't remove a connector from an already exposed
* port, so just throw the port out and make sure we
* reprobe the link address of it's parent MSTB
*/
drm_dp_mst_topology_unlink_port(mgr, port);
mstb->link_address_sent = false;
dowork = true;
goto out;
}
/* Locking is only needed if the port's exposed to userspace */
drm_modeset_lock(&mgr->base.lock, NULL);
} else if (port->input && !conn_stat->input_port) {
create_connector = true;
/* Reprobe link address so we get num_sdp_streams */
mstb->link_address_sent = false;
dowork = true;
}
old_ddps = port->ddps;
old_input = port->input;
port->input = conn_stat->input_port;
port->ldps = conn_stat->legacy_device_plug_status;
port->ddps = conn_stat->displayport_device_plug_status;
if (old_ddps != port->ddps) {
if (port->ddps) {
dowork = true;
} else {
port->available_pbn = 0;
}
}
new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type;
new_mcs = conn_stat->message_capability_status;
ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
if (ret == 1) {
dowork = true;
} else if (ret < 0) {
DRM_ERROR("Failed to change PDT for port %p: %d\n",
port, ret);
dowork = false;
}
if (!old_input && old_ddps != port->ddps && !port->ddps) {
for (i = 0; i < mgr->max_payloads; i++) {
struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
struct drm_dp_mst_port *port_validated;
if (!vcpi)
continue;
port_validated =
container_of(vcpi, struct drm_dp_mst_port, vcpi);
port_validated =
drm_dp_mst_topology_get_port_validated(mgr, port_validated);
if (!port_validated) {
mutex_lock(&mgr->payload_lock);
vcpi->num_slots = 0;
mutex_unlock(&mgr->payload_lock);
} else {
drm_dp_mst_topology_put_port(port_validated);
}
}
}
if (port->connector)
drm_modeset_unlock(&mgr->base.lock);
else if (create_connector)
drm_dp_mst_port_add_connector(mstb, port);
out:
drm_dp_mst_topology_put_port(port);
if (dowork)
queue_work(system_long_wq, &mstb->mgr->work);
}
static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
u8 lct, u8 *rad)
{
struct drm_dp_mst_branch *mstb;
struct drm_dp_mst_port *port;
int i, ret;
/* find the port by iterating down */
mutex_lock(&mgr->lock);
mstb = mgr->mst_primary;
if (!mstb)
goto out;
for (i = 0; i < lct - 1; i++) {
int shift = (i % 2) ? 0 : 4;
int port_num = (rad[i / 2] >> shift) & 0xf;
list_for_each_entry(port, &mstb->ports, next) {
if (port->port_num == port_num) {
mstb = port->mstb;
if (!mstb) {
DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
goto out;
}
break;
}
}
}
ret = drm_dp_mst_topology_try_get_mstb(mstb);
if (!ret)
mstb = NULL;
out:
mutex_unlock(&mgr->lock);
return mstb;
}
static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
struct drm_dp_mst_branch *mstb,
const uint8_t *guid)
{
struct drm_dp_mst_branch *found_mstb;
struct drm_dp_mst_port *port;
if (memcmp(mstb->guid, guid, 16) == 0)
return mstb;
list_for_each_entry(port, &mstb->ports, next) {
if (!port->mstb)
continue;
found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
if (found_mstb)
return found_mstb;
}
return NULL;
}
static struct drm_dp_mst_branch *
drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr,
const uint8_t *guid)
{
struct drm_dp_mst_branch *mstb;
int ret;
/* find the port by iterating down */
mutex_lock(&mgr->lock);
mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
if (mstb) {
ret = drm_dp_mst_topology_try_get_mstb(mstb);
if (!ret)
mstb = NULL;
}
mutex_unlock(&mgr->lock);
return mstb;
}
static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb)
{
struct drm_dp_mst_port *port;
int ret;
bool changed = false;
if (!mstb->link_address_sent) {
ret = drm_dp_send_link_address(mgr, mstb);
if (ret == 1)
changed = true;
else if (ret < 0)
return ret;
}
list_for_each_entry(port, &mstb->ports, next) {
struct drm_dp_mst_branch *mstb_child = NULL;
if (port->input || !port->ddps)
continue;
if (!port->available_pbn) {
drm_modeset_lock(&mgr->base.lock, NULL);
drm_dp_send_enum_path_resources(mgr, mstb, port);
drm_modeset_unlock(&mgr->base.lock);
changed = true;
}
if (port->mstb)
mstb_child = drm_dp_mst_topology_get_mstb_validated(
mgr, port->mstb);
if (mstb_child) {
ret = drm_dp_check_and_send_link_address(mgr,
mstb_child);
drm_dp_mst_topology_put_mstb(mstb_child);
if (ret == 1)
changed = true;
else if (ret < 0)
return ret;
}
}
return changed;
}
static void drm_dp_mst_link_probe_work(struct work_struct *work)
{
struct drm_dp_mst_topology_mgr *mgr =
container_of(work, struct drm_dp_mst_topology_mgr, work);
struct drm_device *dev = mgr->dev;
struct drm_dp_mst_branch *mstb;
int ret;
bool clear_payload_id_table;
mutex_lock(&mgr->probe_lock);
mutex_lock(&mgr->lock);
clear_payload_id_table = !mgr->payload_id_table_cleared;
mgr->payload_id_table_cleared = true;
mstb = mgr->mst_primary;
if (mstb) {
ret = drm_dp_mst_topology_try_get_mstb(mstb);
if (!ret)
mstb = NULL;
}
mutex_unlock(&mgr->lock);
if (!mstb) {
mutex_unlock(&mgr->probe_lock);
return;
}
/*
* Certain branch devices seem to incorrectly report an available_pbn
* of 0 on downstream sinks, even after clearing the
* DP_PAYLOAD_ALLOCATE_* registers in
* drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C
* 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make
* things work again.
*/
if (clear_payload_id_table) {
DRM_DEBUG_KMS("Clearing payload ID table\n");
drm_dp_send_clear_payload_id_table(mgr, mstb);
}
ret = drm_dp_check_and_send_link_address(mgr, mstb);
drm_dp_mst_topology_put_mstb(mstb);
mutex_unlock(&mgr->probe_lock);
if (ret)
drm_kms_helper_hotplug_event(dev);
}
static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
u8 *guid)
{
u64 salt;
if (memchr_inv(guid, 0, 16))
return true;
salt = get_jiffies_64();
memcpy(&guid[0], &salt, sizeof(u64));
memcpy(&guid[8], &salt, sizeof(u64));
return false;
}
static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_REMOTE_DPCD_READ;
req.u.dpcd_read.port_number = port_num;
req.u.dpcd_read.dpcd_address = offset;
req.u.dpcd_read.num_bytes = num_bytes;
drm_dp_encode_sideband_req(&req, msg);
return 0;
}
static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
bool up, u8 *msg, int len)
{
int ret;
int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
int tosend, total, offset;
int retries = 0;
retry:
total = len;
offset = 0;
do {
tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
&msg[offset],
tosend);
if (ret != tosend) {
if (ret == -EIO && retries < 5) {
retries++;
goto retry;
}
DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
return -EIO;