[PATCH 02/19] drm/dp: Add support for DP tunneling
Ville Syrjälä
ville.syrjala at linux.intel.com
Wed Feb 7 20:02:18 UTC 2024
On Tue, Jan 23, 2024 at 12:28:33PM +0200, Imre Deak wrote:
> +static char yes_no_chr(int val)
> +{
> + return val ? 'Y' : 'N';
> +}
We have str_yes_no() already.
v> +
> +#define SKIP_DPRX_CAPS_CHECK BIT(0)
> +#define ALLOW_ALLOCATED_BW_CHANGE BIT(1)
> +
> +static bool tunnel_regs_are_valid(struct drm_dp_tunnel_mgr *mgr,
> + const struct drm_dp_tunnel_regs *regs,
> + unsigned int flags)
> +{
> + int drv_group_id = tunnel_reg_drv_group_id(regs);
> + bool check_dprx = !(flags & SKIP_DPRX_CAPS_CHECK);
> + bool ret = true;
> +
> + if (!tunnel_reg_bw_alloc_supported(regs)) {
> + if (tunnel_group_id(drv_group_id)) {
> + drm_dbg_kms(mgr->dev,
> + "DPTUN: A non-zero group ID is only allowed with BWA support\n");
> + ret = false;
> + }
> +
> + if (tunnel_reg(regs, DP_ALLOCATED_BW)) {
> + drm_dbg_kms(mgr->dev,
> + "DPTUN: BW is allocated without BWA support\n");
> + ret = false;
> + }
> +
> + return ret;
> + }
> +
> + if (!tunnel_group_id(drv_group_id)) {
> + drm_dbg_kms(mgr->dev,
> + "DPTUN: BWA support requires a non-zero group ID\n");
> + ret = false;
> + }
> +
> + if (check_dprx && hweight8(tunnel_reg_max_dprx_lane_count(regs)) != 1) {
> + drm_dbg_kms(mgr->dev,
> + "DPTUN: Invalid DPRX lane count: %d\n",
> + tunnel_reg_max_dprx_lane_count(regs));
> +
> + ret = false;
> + }
> +
> + if (check_dprx && !tunnel_reg_max_dprx_rate(regs)) {
> + drm_dbg_kms(mgr->dev,
> + "DPTUN: DPRX rate is 0\n");
> +
> + ret = false;
> + }
> +
> + if (tunnel_reg(regs, DP_ALLOCATED_BW) > tunnel_reg(regs, DP_ESTIMATED_BW)) {
> + drm_dbg_kms(mgr->dev,
> + "DPTUN: Allocated BW %d > estimated BW %d Mb/s\n",
> + DPTUN_BW_ARG(tunnel_reg(regs, DP_ALLOCATED_BW) *
> + tunnel_reg_bw_granularity(regs)),
> + DPTUN_BW_ARG(tunnel_reg(regs, DP_ESTIMATED_BW) *
> + tunnel_reg_bw_granularity(regs)));
> +
> + ret = false;
> + }
> +
> + return ret;
> +}
> +
> +static bool tunnel_info_changes_are_valid(struct drm_dp_tunnel *tunnel,
> + const struct drm_dp_tunnel_regs *regs,
> + unsigned int flags)
> +{
> + int new_drv_group_id = tunnel_reg_drv_group_id(regs);
> + bool ret = true;
> +
> + if (tunnel->bw_alloc_supported != tunnel_reg_bw_alloc_supported(regs)) {
> + tun_dbg(tunnel,
> + "BW alloc support has changed %c -> %c\n",
> + yes_no_chr(tunnel->bw_alloc_supported),
> + yes_no_chr(tunnel_reg_bw_alloc_supported(regs)));
> +
> + ret = false;
> + }
> +
> + if (tunnel->group->drv_group_id != new_drv_group_id) {
> + tun_dbg(tunnel,
> + "Driver/group ID has changed %d:%d:* -> %d:%d:*\n",
> + tunnel_group_drv_id(tunnel->group->drv_group_id),
> + tunnel_group_id(tunnel->group->drv_group_id),
> + tunnel_group_drv_id(new_drv_group_id),
> + tunnel_group_id(new_drv_group_id));
> +
> + ret = false;
> + }
> +
> + if (!tunnel->bw_alloc_supported)
> + return ret;
> +
> + if (tunnel->bw_granularity != tunnel_reg_bw_granularity(regs)) {
> + tun_dbg(tunnel,
> + "BW granularity has changed: %d -> %d Mb/s\n",
> + DPTUN_BW_ARG(tunnel->bw_granularity),
> + DPTUN_BW_ARG(tunnel_reg_bw_granularity(regs)));
> +
> + ret = false;
> + }
> +
> + /*
> + * On some devices at least the BW alloc mode enabled status is always
> + * reported as 0, so skip checking that here.
> + */
So it's reported as supported and we enable it, but it's never
reported back as being enabled?
> +
> + if (!(flags & ALLOW_ALLOCATED_BW_CHANGE) &&
> + tunnel->allocated_bw !=
> + tunnel_reg(regs, DP_ALLOCATED_BW) * tunnel->bw_granularity) {
> + tun_dbg(tunnel,
> + "Allocated BW has changed: %d -> %d Mb/s\n",
> + DPTUN_BW_ARG(tunnel->allocated_bw),
> + DPTUN_BW_ARG(tunnel_reg(regs, DP_ALLOCATED_BW) * tunnel->bw_granularity));
> +
> + ret = false;
> + }
> +
> + return ret;
> +}
> +
> +static int
> +read_and_verify_tunnel_regs(struct drm_dp_tunnel *tunnel,
> + struct drm_dp_tunnel_regs *regs,
> + unsigned int flags)
> +{
> + int err;
> +
> + err = read_tunnel_regs(tunnel->aux, regs);
> + if (err < 0) {
> + drm_dp_tunnel_set_io_error(tunnel);
> +
> + return err;
> + }
> +
> + if (!tunnel_regs_are_valid(tunnel->group->mgr, regs, flags))
> + return -EINVAL;
> +
> + if (!tunnel_info_changes_are_valid(tunnel, regs, flags))
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +static bool update_dprx_caps(struct drm_dp_tunnel *tunnel, const struct drm_dp_tunnel_regs *regs)
> +{
> + bool changed = false;
> +
> + if (tunnel_reg_max_dprx_rate(regs) != tunnel->max_dprx_rate) {
> + tunnel->max_dprx_rate = tunnel_reg_max_dprx_rate(regs);
> + changed = true;
> + }
> +
> + if (tunnel_reg_max_dprx_lane_count(regs) != tunnel->max_dprx_lane_count) {
> + tunnel->max_dprx_lane_count = tunnel_reg_max_dprx_lane_count(regs);
> + changed = true;
> + }
> +
> + return changed;
> +}
> +
> +static int dev_id_len(const u8 *dev_id, int max_len)
> +{
> + while (max_len && dev_id[max_len - 1] == '\0')
> + max_len--;
> +
> + return max_len;
> +}
> +
> +static int get_max_dprx_bw(const struct drm_dp_tunnel *tunnel)
> +{
> + int bw = drm_dp_max_dprx_data_rate(tunnel->max_dprx_rate,
> + tunnel->max_dprx_lane_count);
> +
> + return min(roundup(bw, tunnel->bw_granularity),
Should this round down?
> + MAX_DP_REQUEST_BW * tunnel->bw_granularity);
> +}
> +
> +static int get_max_tunnel_bw(const struct drm_dp_tunnel *tunnel)
> +{
> + return min(get_max_dprx_bw(tunnel), tunnel->group->available_bw);
> +}
> +
> +/**
> + * drm_dp_tunnel_detect - Detect DP tunnel on the link
> + * @mgr: Tunnel manager
> + * @aux: DP AUX on which the tunnel will be detected
> + *
> + * Detect if there is any DP tunnel on the link and add it to the tunnel
> + * group's tunnel list.
> + *
> + * Returns 0 on success, negative error code on failure.
> + */
> +struct drm_dp_tunnel *
> +drm_dp_tunnel_detect(struct drm_dp_tunnel_mgr *mgr,
> + struct drm_dp_aux *aux)
> +{
> + struct drm_dp_tunnel_regs regs;
> + struct drm_dp_tunnel *tunnel;
> + int err;
> +
> + err = read_tunnel_regs(aux, ®s);
> + if (err)
> + return ERR_PTR(err);
> +
> + if (!(tunnel_reg(®s, DP_TUNNELING_CAPABILITIES) &
> + DP_TUNNELING_SUPPORT))
> + return ERR_PTR(-ENODEV);
> +
> + /* The DPRX caps are valid only after enabling BW alloc mode. */
> + if (!tunnel_regs_are_valid(mgr, ®s, SKIP_DPRX_CAPS_CHECK))
> + return ERR_PTR(-EINVAL);
> +
> + tunnel = create_tunnel(mgr, aux, ®s);
> + if (!tunnel)
> + return ERR_PTR(-ENOMEM);
> +
> + tun_dbg(tunnel,
> + "OUI:%*phD DevID:%*pE Rev-HW:%d.%d SW:%d.%d PR-Sup:%c BWA-Sup:%c BWA-En:%c\n",
> + DP_TUNNELING_OUI_BYTES,
> + tunnel_reg_ptr(®s, DP_TUNNELING_OUI),
> + dev_id_len(tunnel_reg_ptr(®s, DP_TUNNELING_DEV_ID), DP_TUNNELING_DEV_ID_BYTES),
> + tunnel_reg_ptr(®s, DP_TUNNELING_DEV_ID),
> + (tunnel_reg(®s, DP_TUNNELING_HW_REV) & DP_TUNNELING_HW_REV_MAJOR_MASK) >>
> + DP_TUNNELING_HW_REV_MAJOR_SHIFT,
> + (tunnel_reg(®s, DP_TUNNELING_HW_REV) & DP_TUNNELING_HW_REV_MINOR_MASK) >>
> + DP_TUNNELING_HW_REV_MINOR_SHIFT,
> + tunnel_reg(®s, DP_TUNNELING_SW_REV_MAJOR),
> + tunnel_reg(®s, DP_TUNNELING_SW_REV_MINOR),
> + yes_no_chr(tunnel_reg(®s, DP_TUNNELING_CAPABILITIES) &
> + DP_PANEL_REPLAY_OPTIMIZATION_SUPPORT),
> + yes_no_chr(tunnel->bw_alloc_supported),
> + yes_no_chr(tunnel->bw_alloc_enabled));
> +
> + return tunnel;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_detect);
> +
> +/**
> + * drm_dp_tunnel_destroy - Destroy tunnel object
> + * @tunnel: Tunnel object
> + *
> + * Remove the tunnel from the tunnel topology and destroy it.
> + */
> +int drm_dp_tunnel_destroy(struct drm_dp_tunnel *tunnel)
> +{
> + if (drm_WARN_ON(tunnel->group->mgr->dev, tunnel->destroyed))
> + return -ENODEV;
> +
> + tun_dbg(tunnel, "destroying\n");
> +
> + tunnel->destroyed = true;
> + destroy_tunnel(tunnel);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_destroy);
> +
> +static int check_tunnel(const struct drm_dp_tunnel *tunnel)
> +{
> + if (tunnel->destroyed)
> + return -ENODEV;
> +
> + if (tunnel->has_io_error)
> + return -EIO;
> +
> + return 0;
> +}
> +
> +static int group_allocated_bw(struct drm_dp_tunnel_group *group)
> +{
> + struct drm_dp_tunnel *tunnel;
> + int group_allocated_bw = 0;
> +
> + for_each_tunnel_in_group(group, tunnel) {
> + if (check_tunnel(tunnel) == 0 &&
> + tunnel->bw_alloc_enabled)
> + group_allocated_bw += tunnel->allocated_bw;
> + }
> +
> + return group_allocated_bw;
> +}
> +
> +static int calc_group_available_bw(const struct drm_dp_tunnel *tunnel)
> +{
> + return group_allocated_bw(tunnel->group) -
> + tunnel->allocated_bw +
> + tunnel->estimated_bw;
Hmm. So the estimated_bw=actually_free_bw + tunnel->allocated_bw?
Ie. how much bw might be available for this tunnel right now?
And here we're trying to deduce the total bandwidth available by
adding in the allocated_bw of all the other tunnels in the group?
Rather weird that we can't just get that number directly...
> +}
> +
> +static int update_group_available_bw(struct drm_dp_tunnel *tunnel,
> + const struct drm_dp_tunnel_regs *regs)
> +{
> + struct drm_dp_tunnel *tunnel_iter;
> + int group_available_bw;
> + bool changed;
> +
> + tunnel->estimated_bw = tunnel_reg(regs, DP_ESTIMATED_BW) * tunnel->bw_granularity;
> +
> + if (calc_group_available_bw(tunnel) == tunnel->group->available_bw)
> + return 0;
> +
> + for_each_tunnel_in_group(tunnel->group, tunnel_iter) {
> + int err;
> +
> + if (tunnel_iter == tunnel)
> + continue;
> +
> + if (check_tunnel(tunnel_iter) != 0 ||
> + !tunnel_iter->bw_alloc_enabled)
> + continue;
> +
> + err = drm_dp_dpcd_probe(tunnel_iter->aux, DP_DPCD_REV);
> + if (err) {
> + tun_dbg(tunnel_iter,
> + "Probe failed, assume disconnected (err %pe)\n",
> + ERR_PTR(err));
> + drm_dp_tunnel_set_io_error(tunnel_iter);
> + }
> + }
> +
> + group_available_bw = calc_group_available_bw(tunnel);
> +
> + tun_dbg(tunnel, "Updated group available BW: %d->%d\n",
> + DPTUN_BW_ARG(tunnel->group->available_bw),
> + DPTUN_BW_ARG(group_available_bw));
> +
> + changed = tunnel->group->available_bw != group_available_bw;
> +
> + tunnel->group->available_bw = group_available_bw;
> +
> + return changed ? 1 : 0;
> +}
> +
> +static int set_bw_alloc_mode(struct drm_dp_tunnel *tunnel, bool enable)
> +{
> + u8 mask = DP_DISPLAY_DRIVER_BW_ALLOCATION_MODE_ENABLE | DP_UNMASK_BW_ALLOCATION_IRQ;
> + u8 val;
> +
> + if (drm_dp_dpcd_readb(tunnel->aux, DP_DPTX_BW_ALLOCATION_MODE_CONTROL, &val) < 0)
> + goto out_err;
> +
> + if (enable)
> + val |= mask;
> + else
> + val &= ~mask;
> +
> + if (drm_dp_dpcd_writeb(tunnel->aux, DP_DPTX_BW_ALLOCATION_MODE_CONTROL, val) < 0)
> + goto out_err;
> +
> + tunnel->bw_alloc_enabled = enable;
> +
> + return 0;
> +
> +out_err:
> + drm_dp_tunnel_set_io_error(tunnel);
> +
> + return -EIO;
> +}
> +
> +/**
> + * drm_dp_tunnel_enable_bw_alloc: Enable DP tunnel BW allocation mode
> + * @tunnel: Tunnel object
> + *
> + * Enable the DP tunnel BW allocation mode on @tunnel if it supports it.
> + *
> + * Returns 0 in case of success, negative error code otherwise.
> + */
> +int drm_dp_tunnel_enable_bw_alloc(struct drm_dp_tunnel *tunnel)
> +{
> + struct drm_dp_tunnel_regs regs;
> + int err = check_tunnel(tunnel);
> +
> + if (err)
> + return err;
> +
> + if (!tunnel->bw_alloc_supported)
> + return -EOPNOTSUPP;
> +
> + if (!tunnel_group_id(tunnel->group->drv_group_id))
> + return -EINVAL;
> +
> + err = set_bw_alloc_mode(tunnel, true);
> + if (err)
> + goto out;
> +
> + err = read_and_verify_tunnel_regs(tunnel, ®s, 0);
> + if (err) {
> + set_bw_alloc_mode(tunnel, false);
> +
> + goto out;
> + }
> +
> + if (!tunnel->max_dprx_rate)
> + update_dprx_caps(tunnel, ®s);
> +
> + if (tunnel->group->available_bw == -1) {
> + err = update_group_available_bw(tunnel, ®s);
> + if (err > 0)
> + err = 0;
> + }
> +out:
> + tun_dbg_stat(tunnel, err,
> + "Enabling BW alloc mode: DPRX:%dx%d Group alloc:%d/%d Mb/s",
> + tunnel->max_dprx_rate / 100, tunnel->max_dprx_lane_count,
> + DPTUN_BW_ARG(group_allocated_bw(tunnel->group)),
> + DPTUN_BW_ARG(tunnel->group->available_bw));
> +
> + return err;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_enable_bw_alloc);
> +
> +/**
> + * drm_dp_tunnel_disable_bw_alloc: Disable DP tunnel BW allocation mode
> + * @tunnel: Tunnel object
> + *
> + * Disable the DP tunnel BW allocation mode on @tunnel.
> + *
> + * Returns 0 in case of success, negative error code otherwise.
> + */
> +int drm_dp_tunnel_disable_bw_alloc(struct drm_dp_tunnel *tunnel)
> +{
> + int err = check_tunnel(tunnel);
> +
> + if (err)
> + return err;
> +
> + err = set_bw_alloc_mode(tunnel, false);
> +
> + tun_dbg_stat(tunnel, err, "Disabling BW alloc mode");
> +
> + return err;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_disable_bw_alloc);
> +
> +bool drm_dp_tunnel_bw_alloc_is_enabled(const struct drm_dp_tunnel *tunnel)
> +{
> + return tunnel->bw_alloc_enabled;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_bw_alloc_is_enabled);
> +
> +static int bw_req_complete(struct drm_dp_aux *aux, bool *status_changed)
> +{
> + u8 bw_req_mask = DP_BW_REQUEST_SUCCEEDED | DP_BW_REQUEST_FAILED;
> + u8 status_change_mask = DP_BW_ALLOCATION_CAPABILITY_CHANGED | DP_ESTIMATED_BW_CHANGED;
> + u8 val;
> +
> + if (drm_dp_dpcd_readb(aux, DP_TUNNELING_STATUS, &val) < 0)
> + return -EIO;
> +
> + *status_changed = val & status_change_mask;
> +
> + val &= bw_req_mask;
> +
> + if (!val)
> + return -EAGAIN;
> +
> + if (drm_dp_dpcd_writeb(aux, DP_TUNNELING_STATUS, val) < 0)
> + return -EIO;
> +
> + return val == DP_BW_REQUEST_SUCCEEDED ? 0 : -ENOSPC;
> +}
> +
> +static int allocate_tunnel_bw(struct drm_dp_tunnel *tunnel, int bw)
> +{
> + struct drm_dp_tunnel_mgr *mgr = tunnel->group->mgr;
> + int request_bw = DIV_ROUND_UP(bw, tunnel->bw_granularity);
> + unsigned long wait_expires;
> + DEFINE_WAIT(wait);
> + int err;
> +
> + /* Atomic check should prevent the following. */
> + if (drm_WARN_ON(mgr->dev, request_bw > MAX_DP_REQUEST_BW)) {
> + err = -EINVAL;
> + goto out;
> + }
> +
> + if (drm_dp_dpcd_writeb(tunnel->aux, DP_REQUEST_BW, request_bw) < 0) {
> + err = -EIO;
> + goto out;
> + }
> +
> + wait_expires = jiffies + msecs_to_jiffies(3000);
> +
> + for (;;) {
> + bool status_changed;
> +
> + err = bw_req_complete(tunnel->aux, &status_changed);
> + if (err != -EAGAIN)
> + break;
> +
> + if (status_changed) {
> + struct drm_dp_tunnel_regs regs;
> +
> + err = read_and_verify_tunnel_regs(tunnel, ®s,
> + ALLOW_ALLOCATED_BW_CHANGE);
> + if (err)
> + break;
> + }
> +
> + if (time_after(jiffies, wait_expires)) {
> + err = -ETIMEDOUT;
> + break;
> + }
> +
> + prepare_to_wait(&mgr->bw_req_queue, &wait, TASK_UNINTERRUPTIBLE);
> + schedule_timeout(msecs_to_jiffies(200));
> + };
> +
> + finish_wait(&mgr->bw_req_queue, &wait);
> +
> + if (err)
> + goto out;
> +
> + tunnel->allocated_bw = request_bw * tunnel->bw_granularity;
> +
> +out:
> + tun_dbg_stat(tunnel, err, "Allocating %d/%d Mb/s for tunnel: Group alloc:%d/%d Mb/s",
> + DPTUN_BW_ARG(request_bw * tunnel->bw_granularity),
> + DPTUN_BW_ARG(get_max_tunnel_bw(tunnel)),
> + DPTUN_BW_ARG(group_allocated_bw(tunnel->group)),
> + DPTUN_BW_ARG(tunnel->group->available_bw));
> +
> + if (err == -EIO)
> + drm_dp_tunnel_set_io_error(tunnel);
> +
> + return err;
> +}
> +
> +int drm_dp_tunnel_alloc_bw(struct drm_dp_tunnel *tunnel, int bw)
> +{
> + int err = check_tunnel(tunnel);
> +
> + if (err)
> + return err;
> +
> + return allocate_tunnel_bw(tunnel, bw);
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_alloc_bw);
> +
> +static int check_and_clear_status_change(struct drm_dp_tunnel *tunnel)
> +{
> + u8 mask = DP_BW_ALLOCATION_CAPABILITY_CHANGED | DP_ESTIMATED_BW_CHANGED;
> + u8 val;
> +
> + if (drm_dp_dpcd_readb(tunnel->aux, DP_TUNNELING_STATUS, &val) < 0)
> + goto out_err;
> +
> + val &= mask;
> +
> + if (val) {
> + if (drm_dp_dpcd_writeb(tunnel->aux, DP_TUNNELING_STATUS, val) < 0)
> + goto out_err;
> +
> + return 1;
> + }
> +
> + if (!drm_dp_tunnel_bw_alloc_is_enabled(tunnel))
> + return 0;
> +
> + /*
> + * Check for estimated BW changes explicitly to account for lost
> + * BW change notifications.
> + */
> + if (drm_dp_dpcd_readb(tunnel->aux, DP_ESTIMATED_BW, &val) < 0)
> + goto out_err;
> +
> + if (val * tunnel->bw_granularity != tunnel->estimated_bw)
> + return 1;
> +
> + return 0;
> +
> +out_err:
> + drm_dp_tunnel_set_io_error(tunnel);
> +
> + return -EIO;
> +}
> +
> +/**
> + * drm_dp_tunnel_update_state: Update DP tunnel SW state with the HW state
> + * @tunnel: Tunnel object
> + *
> + * Update the SW state of @tunnel with the HW state.
> + *
> + * Returns 0 if the state has not changed, 1 if it has changed and got updated
> + * successfully and a negative error code otherwise.
> + */
> +int drm_dp_tunnel_update_state(struct drm_dp_tunnel *tunnel)
> +{
> + struct drm_dp_tunnel_regs regs;
> + bool changed = false;
> + int ret = check_tunnel(tunnel);
> +
> + if (ret < 0)
> + return ret;
> +
> + ret = check_and_clear_status_change(tunnel);
> + if (ret < 0)
> + goto out;
> +
> + if (!ret)
> + return 0;
> +
> + ret = read_and_verify_tunnel_regs(tunnel, ®s, 0);
> + if (ret)
> + goto out;
> +
> + if (update_dprx_caps(tunnel, ®s))
> + changed = true;
> +
> + ret = update_group_available_bw(tunnel, ®s);
> + if (ret == 1)
> + changed = true;
> +
> +out:
> + tun_dbg_stat(tunnel, ret < 0 ? ret : 0,
> + "State update: Changed:%c DPRX:%dx%d Tunnel alloc:%d/%d Group alloc:%d/%d Mb/s",
> + yes_no_chr(changed),
> + tunnel->max_dprx_rate / 100, tunnel->max_dprx_lane_count,
> + DPTUN_BW_ARG(tunnel->allocated_bw),
> + DPTUN_BW_ARG(get_max_tunnel_bw(tunnel)),
> + DPTUN_BW_ARG(group_allocated_bw(tunnel->group)),
> + DPTUN_BW_ARG(tunnel->group->available_bw));
> +
> + if (ret < 0)
> + return ret;
> +
> + if (changed)
> + return 1;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_update_state);
> +
> +/*
> + * Returns 0 if no re-probe is needed, 1 if a re-probe is needed,
> + * a negative error code otherwise.
> + */
> +int drm_dp_tunnel_handle_irq(struct drm_dp_tunnel_mgr *mgr, struct drm_dp_aux *aux)
> +{
> + u8 val;
> +
> + if (drm_dp_dpcd_readb(aux, DP_TUNNELING_STATUS, &val) < 0)
> + return -EIO;
> +
> + if (val & (DP_BW_REQUEST_SUCCEEDED | DP_BW_REQUEST_FAILED))
> + wake_up_all(&mgr->bw_req_queue);
> +
> + if (val & (DP_BW_ALLOCATION_CAPABILITY_CHANGED | DP_ESTIMATED_BW_CHANGED))
> + return 1;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_handle_irq);
> +
> +/**
> + * drm_dp_tunnel_max_dprx_rate - Query the maximum rate of the tunnel's DPRX
> + * @tunnel: Tunnel object
> + *
> + * The function is used to query the maximum link rate of the DPRX connected
> + * to @tunnel. Note that this rate will not be limited by the BW limit of the
> + * tunnel, as opposed to the standard and extended DP_MAX_LINK_RATE DPCD
> + * registers.
> + *
> + * Returns the maximum link rate in 10 kbit/s units.
> + */
> +int drm_dp_tunnel_max_dprx_rate(const struct drm_dp_tunnel *tunnel)
> +{
> + return tunnel->max_dprx_rate;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_max_dprx_rate);
> +
> +/**
> + * drm_dp_tunnel_max_dprx_lane_count - Query the maximum lane count of the tunnel's DPRX
> + * @tunnel: Tunnel object
> + *
> + * The function is used to query the maximum lane count of the DPRX connected
> + * to @tunnel. Note that this lane count will not be limited by the BW limit of
> + * the tunnel, as opposed to the standard and extended DP_MAX_LANE_COUNT DPCD
> + * registers.
> + *
> + * Returns the maximum lane count.
> + */
> +int drm_dp_tunnel_max_dprx_lane_count(const struct drm_dp_tunnel *tunnel)
> +{
> + return tunnel->max_dprx_lane_count;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_max_dprx_lane_count);
> +
> +/**
> + * drm_dp_tunnel_available_bw - Query the estimated total available BW of the tunnel
> + * @tunnel: Tunnel object
> + *
> + * This function is used to query the estimated total available BW of the
> + * tunnel. This includes the currently allocated and free BW for all the
> + * tunnels in @tunnel's group. The available BW is valid only after the BW
> + * allocation mode has been enabled for the tunnel and its state got updated
> + * calling drm_dp_tunnel_update_state().
> + *
> + * Returns the @tunnel group's estimated total available bandwidth in kB/s
> + * units, or -1 if the available BW isn't valid (the BW allocation mode is
> + * not enabled or the tunnel's state hasn't been updated).
> + */
> +int drm_dp_tunnel_available_bw(const struct drm_dp_tunnel *tunnel)
> +{
> + return tunnel->group->available_bw;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_available_bw);
> +
> +static struct drm_dp_tunnel_group_state *
> +drm_dp_tunnel_atomic_get_group_state(struct drm_atomic_state *state,
> + const struct drm_dp_tunnel *tunnel)
> +{
> + return (struct drm_dp_tunnel_group_state *)
> + drm_atomic_get_private_obj_state(state,
> + &tunnel->group->base);
> +}
> +
> +static struct drm_dp_tunnel_state *
> +add_tunnel_state(struct drm_dp_tunnel_group_state *group_state,
> + struct drm_dp_tunnel *tunnel)
> +{
> + struct drm_dp_tunnel_state *tunnel_state;
> +
> + tun_dbg_atomic(tunnel,
> + "Adding state for tunnel %p to group state %p\n",
> + tunnel, group_state);
> +
> + tunnel_state = kzalloc(sizeof(*tunnel_state), GFP_KERNEL);
> + if (!tunnel_state)
> + return NULL;
> +
> + tunnel_state->group_state = group_state;
> +
> + drm_dp_tunnel_ref_get(tunnel, &tunnel_state->tunnel_ref);
> +
> + INIT_LIST_HEAD(&tunnel_state->node);
> + list_add(&tunnel_state->node, &group_state->tunnel_states);
> +
> + return tunnel_state;
> +}
> +
> +void drm_dp_tunnel_atomic_clear_state(struct drm_dp_tunnel_state *tunnel_state)
> +{
> + tun_dbg_atomic(tunnel_state->tunnel_ref.tunnel,
> + "Clearing state for tunnel %p\n",
> + tunnel_state->tunnel_ref.tunnel);
> +
> + list_del(&tunnel_state->node);
> +
> + kfree(tunnel_state->stream_bw);
> + drm_dp_tunnel_ref_put(&tunnel_state->tunnel_ref);
> +
> + kfree(tunnel_state);
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_atomic_clear_state);
> +
> +static void clear_tunnel_group_state(struct drm_dp_tunnel_group_state *group_state)
> +{
> + struct drm_dp_tunnel_state *tunnel_state;
> + struct drm_dp_tunnel_state *tunnel_state_tmp;
> +
> + for_each_tunnel_state_safe(group_state, tunnel_state, tunnel_state_tmp)
> + drm_dp_tunnel_atomic_clear_state(tunnel_state);
> +}
> +
> +static struct drm_dp_tunnel_state *
> +get_tunnel_state(struct drm_dp_tunnel_group_state *group_state,
> + const struct drm_dp_tunnel *tunnel)
> +{
> + struct drm_dp_tunnel_state *tunnel_state;
> +
> + for_each_tunnel_state(group_state, tunnel_state)
> + if (tunnel_state->tunnel_ref.tunnel == tunnel)
> + return tunnel_state;
> +
> + return NULL;
> +}
> +
> +static struct drm_dp_tunnel_state *
> +get_or_add_tunnel_state(struct drm_dp_tunnel_group_state *group_state,
> + struct drm_dp_tunnel *tunnel)
> +{
> + struct drm_dp_tunnel_state *tunnel_state;
> +
> + tunnel_state = get_tunnel_state(group_state, tunnel);
> + if (tunnel_state)
> + return tunnel_state;
> +
> + return add_tunnel_state(group_state, tunnel);
> +}
> +
> +static struct drm_private_state *
> +tunnel_group_duplicate_state(struct drm_private_obj *obj)
> +{
> + struct drm_dp_tunnel_group_state *group_state = to_group_state(obj->state);
> + struct drm_dp_tunnel_state *tunnel_state;
> +
> + group_state = kzalloc(sizeof(*group_state), GFP_KERNEL);
> + if (!group_state)
> + return NULL;
> +
> + INIT_LIST_HEAD(&group_state->tunnel_states);
> +
> + __drm_atomic_helper_private_obj_duplicate_state(obj, &group_state->base);
> +
> + for_each_tunnel_state(to_group_state(obj->state), tunnel_state) {
> + struct drm_dp_tunnel_state *new_tunnel_state;
> +
> + new_tunnel_state = get_or_add_tunnel_state(group_state,
> + tunnel_state->tunnel_ref.tunnel);
> + if (!new_tunnel_state)
> + goto out_free_state;
> +
> + new_tunnel_state->stream_mask = tunnel_state->stream_mask;
> + new_tunnel_state->stream_bw = kmemdup(tunnel_state->stream_bw,
> + sizeof(*tunnel_state->stream_bw) *
> + hweight32(tunnel_state->stream_mask),
> + GFP_KERNEL);
> +
> + if (!new_tunnel_state->stream_bw)
> + goto out_free_state;
> + }
> +
> + return &group_state->base;
> +
> +out_free_state:
> + clear_tunnel_group_state(group_state);
> + kfree(group_state);
> +
> + return NULL;
> +}
> +
> +static void tunnel_group_destroy_state(struct drm_private_obj *obj, struct drm_private_state *state)
> +{
> + struct drm_dp_tunnel_group_state *group_state = to_group_state(state);
> +
> + clear_tunnel_group_state(group_state);
> + kfree(group_state);
> +}
> +
> +static const struct drm_private_state_funcs tunnel_group_funcs = {
> + .atomic_duplicate_state = tunnel_group_duplicate_state,
> + .atomic_destroy_state = tunnel_group_destroy_state,
> +};
> +
> +struct drm_dp_tunnel_state *
> +drm_dp_tunnel_atomic_get_state(struct drm_atomic_state *state,
> + struct drm_dp_tunnel *tunnel)
> +{
> + struct drm_dp_tunnel_group_state *group_state =
> + drm_dp_tunnel_atomic_get_group_state(state, tunnel);
> + struct drm_dp_tunnel_state *tunnel_state;
> +
> + if (IS_ERR(group_state))
> + return ERR_CAST(group_state);
> +
> + tunnel_state = get_or_add_tunnel_state(group_state, tunnel);
> + if (!tunnel_state)
> + return ERR_PTR(-ENOMEM);
> +
> + return tunnel_state;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_atomic_get_state);
> +
> +struct drm_dp_tunnel_state *
> +drm_dp_tunnel_atomic_get_new_state(struct drm_atomic_state *state,
> + const struct drm_dp_tunnel *tunnel)
> +{
> + struct drm_dp_tunnel_group_state *new_group_state;
> + int i;
> +
> + for_each_new_group_in_state(state, new_group_state, i)
> + if (to_group(new_group_state->base.obj) == tunnel->group)
> + return get_tunnel_state(new_group_state, tunnel);
> +
> + return NULL;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_atomic_get_new_state);
> +
> +static bool init_group(struct drm_dp_tunnel_mgr *mgr, struct drm_dp_tunnel_group *group)
> +{
> + struct drm_dp_tunnel_group_state *group_state = kzalloc(sizeof(*group_state), GFP_KERNEL);
> +
> + if (!group_state)
> + return false;
> +
> + INIT_LIST_HEAD(&group_state->tunnel_states);
> +
> + group->mgr = mgr;
> + group->available_bw = -1;
> + INIT_LIST_HEAD(&group->tunnels);
> +
> + drm_atomic_private_obj_init(mgr->dev, &group->base, &group_state->base,
> + &tunnel_group_funcs);
> +
> + return true;
> +}
> +
> +static void cleanup_group(struct drm_dp_tunnel_group *group)
> +{
> + drm_atomic_private_obj_fini(&group->base);
> +}
> +
> +#ifdef CONFIG_DRM_DISPLAY_DEBUG_DP_TUNNEL_STATE
> +static void check_unique_stream_ids(const struct drm_dp_tunnel_group_state *group_state)
> +{
> + const struct drm_dp_tunnel_state *tunnel_state;
> + u32 stream_mask = 0;
> +
> + for_each_tunnel_state(group_state, tunnel_state) {
> + drm_WARN(to_group(group_state->base.obj)->mgr->dev,
> + tunnel_state->stream_mask & stream_mask,
> + "[DPTUN %s]: conflicting stream IDs %x (IDs in other tunnels %x)\n",
> + tunnel_state->tunnel_ref.tunnel->name,
> + tunnel_state->stream_mask,
> + stream_mask);
> +
> + stream_mask |= tunnel_state->stream_mask;
> + }
> +}
> +#else
> +static void check_unique_stream_ids(const struct drm_dp_tunnel_group_state *group_state)
> +{
> +}
> +#endif
> +
> +static int stream_id_to_idx(u32 stream_mask, u8 stream_id)
> +{
> + return hweight32(stream_mask & (BIT(stream_id) - 1));
> +}
> +
> +static int resize_bw_array(struct drm_dp_tunnel_state *tunnel_state,
> + unsigned long old_mask, unsigned long new_mask)
> +{
> + unsigned long move_mask = old_mask & new_mask;
> + int *new_bws = NULL;
> + int id;
> +
> + WARN_ON(!new_mask);
> +
> + if (old_mask == new_mask)
> + return 0;
> +
> + new_bws = kcalloc(hweight32(new_mask), sizeof(*new_bws), GFP_KERNEL);
> + if (!new_bws)
> + return -ENOMEM;
> +
> + for_each_set_bit(id, &move_mask, BITS_PER_TYPE(move_mask))
> + new_bws[stream_id_to_idx(new_mask, id)] =
> + tunnel_state->stream_bw[stream_id_to_idx(old_mask, id)];
> +
> + kfree(tunnel_state->stream_bw);
> + tunnel_state->stream_bw = new_bws;
> + tunnel_state->stream_mask = new_mask;
> +
> + return 0;
> +}
> +
> +static int set_stream_bw(struct drm_dp_tunnel_state *tunnel_state,
> + u8 stream_id, int bw)
> +{
> + int err;
> +
> + err = resize_bw_array(tunnel_state,
> + tunnel_state->stream_mask,
> + tunnel_state->stream_mask | BIT(stream_id));
> + if (err)
> + return err;
> +
> + tunnel_state->stream_bw[stream_id_to_idx(tunnel_state->stream_mask, stream_id)] = bw;
> +
> + return 0;
> +}
> +
> +static int clear_stream_bw(struct drm_dp_tunnel_state *tunnel_state,
> + u8 stream_id)
> +{
> + if (!(tunnel_state->stream_mask & ~BIT(stream_id))) {
> + drm_dp_tunnel_atomic_clear_state(tunnel_state);
> + return 0;
> + }
> +
> + return resize_bw_array(tunnel_state,
> + tunnel_state->stream_mask,
> + tunnel_state->stream_mask & ~BIT(stream_id));
> +}
> +
> +int drm_dp_tunnel_atomic_set_stream_bw(struct drm_atomic_state *state,
> + struct drm_dp_tunnel *tunnel,
> + u8 stream_id, int bw)
> +{
> + struct drm_dp_tunnel_group_state *new_group_state =
> + drm_dp_tunnel_atomic_get_group_state(state, tunnel);
> + struct drm_dp_tunnel_state *tunnel_state;
> + int err;
> +
> + if (drm_WARN_ON(tunnel->group->mgr->dev,
> + stream_id > BITS_PER_TYPE(tunnel_state->stream_mask)))
> + return -EINVAL;
> +
> + tun_dbg(tunnel,
> + "Setting %d Mb/s for stream %d\n",
> + DPTUN_BW_ARG(bw), stream_id);
> +
> + if (bw == 0) {
> + tunnel_state = get_tunnel_state(new_group_state, tunnel);
> + if (!tunnel_state)
> + return 0;
> +
> + return clear_stream_bw(tunnel_state, stream_id);
> + }
> +
> + tunnel_state = get_or_add_tunnel_state(new_group_state, tunnel);
> + if (drm_WARN_ON(state->dev, !tunnel_state))
> + return -EINVAL;
> +
> + err = set_stream_bw(tunnel_state, stream_id, bw);
> + if (err)
> + return err;
> +
> + check_unique_stream_ids(new_group_state);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_atomic_set_stream_bw);
> +
> +int drm_dp_tunnel_atomic_get_tunnel_bw(const struct drm_dp_tunnel_state *tunnel_state)
> +{
> + int tunnel_bw = 0;
> + int i;
> +
> + for (i = 0; i < hweight32(tunnel_state->stream_mask); i++)
> + tunnel_bw += tunnel_state->stream_bw[i];
> +
> + return tunnel_bw;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_atomic_get_tunnel_bw);
> +
> +int drm_dp_tunnel_atomic_get_group_streams_in_state(struct drm_atomic_state *state,
> + const struct drm_dp_tunnel *tunnel,
> + u32 *stream_mask)
> +{
> + struct drm_dp_tunnel_group_state *group_state =
> + drm_dp_tunnel_atomic_get_group_state(state, tunnel);
> + struct drm_dp_tunnel_state *tunnel_state;
> +
> + if (IS_ERR(group_state))
> + return PTR_ERR(group_state);
> +
> + *stream_mask = 0;
> + for_each_tunnel_state(group_state, tunnel_state)
> + *stream_mask |= tunnel_state->stream_mask;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_atomic_get_group_streams_in_state);
> +
> +static int
> +drm_dp_tunnel_atomic_check_group_bw(struct drm_dp_tunnel_group_state *new_group_state,
> + u32 *failed_stream_mask)
> +{
> + struct drm_dp_tunnel_group *group = to_group(new_group_state->base.obj);
> + struct drm_dp_tunnel_state *new_tunnel_state;
> + u32 group_stream_mask = 0;
> + int group_bw = 0;
> +
> + for_each_tunnel_state(new_group_state, new_tunnel_state) {
> + struct drm_dp_tunnel *tunnel = new_tunnel_state->tunnel_ref.tunnel;
> + int max_dprx_bw = get_max_dprx_bw(tunnel);
> + int tunnel_bw = drm_dp_tunnel_atomic_get_tunnel_bw(new_tunnel_state);
> +
> + tun_dbg(tunnel,
> + "%sRequired %d/%d Mb/s total for tunnel.\n",
> + tunnel_bw > max_dprx_bw ? "Not enough BW: " : "",
> + DPTUN_BW_ARG(tunnel_bw),
> + DPTUN_BW_ARG(max_dprx_bw));
> +
> + if (tunnel_bw > max_dprx_bw) {
I'm a bit confused why we're checking this here. Aren't we already
checking this somewhere else?
> + *failed_stream_mask = new_tunnel_state->stream_mask;
> + return -ENOSPC;
> + }
> +
> + group_bw += min(roundup(tunnel_bw, tunnel->bw_granularity),
> + max_dprx_bw);
> + group_stream_mask |= new_tunnel_state->stream_mask;
> + }
> +
> + tun_grp_dbg(group,
> + "%sRequired %d/%d Mb/s total for tunnel group.\n",
> + group_bw > group->available_bw ? "Not enough BW: " : "",
> + DPTUN_BW_ARG(group_bw),
> + DPTUN_BW_ARG(group->available_bw));
> +
> + if (group_bw > group->available_bw) {
> + *failed_stream_mask = group_stream_mask;
> + return -ENOSPC;
> + }
> +
> + return 0;
> +}
> +
> +int drm_dp_tunnel_atomic_check_stream_bws(struct drm_atomic_state *state,
> + u32 *failed_stream_mask)
> +{
> + struct drm_dp_tunnel_group_state *new_group_state;
> + int i;
> +
> + for_each_new_group_in_state(state, new_group_state, i) {
> + int ret;
> +
> + ret = drm_dp_tunnel_atomic_check_group_bw(new_group_state,
> + failed_stream_mask);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_atomic_check_stream_bws);
> +
> +static void destroy_mgr(struct drm_dp_tunnel_mgr *mgr)
> +{
> + int i;
> +
> + for (i = 0; i < mgr->group_count; i++) {
> + cleanup_group(&mgr->groups[i]);
> + drm_WARN_ON(mgr->dev, !list_empty(&mgr->groups[i].tunnels));
> + }
> +
> +#ifdef CONFIG_DRM_DISPLAY_DEBUG_DP_TUNNEL_STATE
> + ref_tracker_dir_exit(&mgr->ref_tracker);
> +#endif
> +
> + kfree(mgr->groups);
> + kfree(mgr);
> +}
> +
> +/**
> + * drm_dp_tunnel_mgr_create - Create a DP tunnel manager
> + * @i915: i915 driver object
> + *
> + * Creates a DP tunnel manager.
> + *
> + * Returns a pointer to the tunnel manager if created successfully or NULL in
> + * case of an error.
> + */
> +struct drm_dp_tunnel_mgr *
> +drm_dp_tunnel_mgr_create(struct drm_device *dev, int max_group_count)
> +{
> + struct drm_dp_tunnel_mgr *mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
> + int i;
> +
> + if (!mgr)
> + return NULL;
> +
> + mgr->dev = dev;
> + init_waitqueue_head(&mgr->bw_req_queue);
> +
> + mgr->groups = kcalloc(max_group_count, sizeof(*mgr->groups), GFP_KERNEL);
> + if (!mgr->groups) {
> + kfree(mgr);
> +
> + return NULL;
> + }
> +
> +#ifdef CONFIG_DRM_DISPLAY_DEBUG_DP_TUNNEL_STATE
> + ref_tracker_dir_init(&mgr->ref_tracker, 16, "dptun");
> +#endif
> +
> + for (i = 0; i < max_group_count; i++) {
> + if (!init_group(mgr, &mgr->groups[i])) {
> + destroy_mgr(mgr);
> +
> + return NULL;
> + }
> +
> + mgr->group_count++;
> + }
> +
> + return mgr;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_mgr_create);
> +
> +/**
> + * drm_dp_tunnel_mgr_destroy - Destroy DP tunnel manager
> + * @mgr: Tunnel manager object
> + *
> + * Destroy the tunnel manager.
> + */
> +void drm_dp_tunnel_mgr_destroy(struct drm_dp_tunnel_mgr *mgr)
> +{
> + destroy_mgr(mgr);
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_mgr_destroy);
> diff --git a/include/drm/display/drm_dp.h b/include/drm/display/drm_dp.h
> index 281afff6ee4e5..8bfd5d007be8d 100644
> --- a/include/drm/display/drm_dp.h
> +++ b/include/drm/display/drm_dp.h
> @@ -1382,6 +1382,66 @@
> #define DP_HDCP_2_2_REG_STREAM_TYPE_OFFSET 0x69494
> #define DP_HDCP_2_2_REG_DBG_OFFSET 0x69518
>
> +/* DP-tunneling */
> +#define DP_TUNNELING_OUI 0xe0000
> +#define DP_TUNNELING_OUI_BYTES 3
> +
> +#define DP_TUNNELING_DEV_ID 0xe0003
> +#define DP_TUNNELING_DEV_ID_BYTES 6
> +
> +#define DP_TUNNELING_HW_REV 0xe0009
> +#define DP_TUNNELING_HW_REV_MAJOR_SHIFT 4
> +#define DP_TUNNELING_HW_REV_MAJOR_MASK (0xf << DP_TUNNELING_HW_REV_MAJOR_SHIFT)
> +#define DP_TUNNELING_HW_REV_MINOR_SHIFT 0
> +#define DP_TUNNELING_HW_REV_MINOR_MASK (0xf << DP_TUNNELING_HW_REV_MINOR_SHIFT)
> +
> +#define DP_TUNNELING_SW_REV_MAJOR 0xe000a
> +#define DP_TUNNELING_SW_REV_MINOR 0xe000b
> +
> +#define DP_TUNNELING_CAPABILITIES 0xe000d
> +#define DP_IN_BW_ALLOCATION_MODE_SUPPORT (1 << 7)
> +#define DP_PANEL_REPLAY_OPTIMIZATION_SUPPORT (1 << 6)
> +#define DP_TUNNELING_SUPPORT (1 << 0)
> +
> +#define DP_IN_ADAPTER_INFO 0xe000e
> +#define DP_IN_ADAPTER_NUMBER_BITS 7
> +#define DP_IN_ADAPTER_NUMBER_MASK ((1 << DP_IN_ADAPTER_NUMBER_BITS) - 1)
> +
> +#define DP_USB4_DRIVER_ID 0xe000f
> +#define DP_USB4_DRIVER_ID_BITS 4
> +#define DP_USB4_DRIVER_ID_MASK ((1 << DP_USB4_DRIVER_ID_BITS) - 1)
> +
> +#define DP_USB4_DRIVER_BW_CAPABILITY 0xe0020
> +#define DP_USB4_DRIVER_BW_ALLOCATION_MODE_SUPPORT (1 << 7)
> +
> +#define DP_IN_ADAPTER_TUNNEL_INFORMATION 0xe0021
> +#define DP_GROUP_ID_BITS 3
> +#define DP_GROUP_ID_MASK ((1 << DP_GROUP_ID_BITS) - 1)
> +
> +#define DP_BW_GRANULARITY 0xe0022
> +#define DP_BW_GRANULARITY_MASK 0x3
> +
> +#define DP_ESTIMATED_BW 0xe0023
> +#define DP_ALLOCATED_BW 0xe0024
> +
> +#define DP_TUNNELING_STATUS 0xe0025
> +#define DP_BW_ALLOCATION_CAPABILITY_CHANGED (1 << 3)
> +#define DP_ESTIMATED_BW_CHANGED (1 << 2)
> +#define DP_BW_REQUEST_SUCCEEDED (1 << 1)
> +#define DP_BW_REQUEST_FAILED (1 << 0)
> +
> +#define DP_TUNNELING_MAX_LINK_RATE 0xe0028
> +
> +#define DP_TUNNELING_MAX_LANE_COUNT 0xe0029
> +#define DP_TUNNELING_MAX_LANE_COUNT_MASK 0x1f
> +
> +#define DP_DPTX_BW_ALLOCATION_MODE_CONTROL 0xe0030
> +#define DP_DISPLAY_DRIVER_BW_ALLOCATION_MODE_ENABLE (1 << 7)
> +#define DP_UNMASK_BW_ALLOCATION_IRQ (1 << 6)
> +
> +#define DP_REQUEST_BW 0xe0031
> +#define MAX_DP_REQUEST_BW 255
> +
> /* LTTPR: Link Training (LT)-tunable PHY Repeaters */
> #define DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV 0xf0000 /* 1.3 */
> #define DP_MAX_LINK_RATE_PHY_REPEATER 0xf0001 /* 1.4a */
> diff --git a/include/drm/display/drm_dp_tunnel.h b/include/drm/display/drm_dp_tunnel.h
> new file mode 100644
> index 0000000000000..f6449b1b4e6e9
> --- /dev/null
> +++ b/include/drm/display/drm_dp_tunnel.h
> @@ -0,0 +1,270 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2023 Intel Corporation
> + */
> +
> +#ifndef __DRM_DP_TUNNEL_H__
> +#define __DRM_DP_TUNNEL_H__
> +
> +#include <linux/err.h>
> +#include <linux/errno.h>
> +#include <linux/types.h>
> +
> +struct drm_dp_aux;
> +
> +struct drm_device;
> +
> +struct drm_atomic_state;
> +struct drm_dp_tunnel_mgr;
> +struct drm_dp_tunnel_state;
> +
> +struct ref_tracker;
> +
> +struct drm_dp_tunnel_ref {
> + struct drm_dp_tunnel *tunnel;
> +#ifdef CONFIG_DRM_DISPLAY_DEBUG_DP_TUNNEL_STATE
> + struct ref_tracker *tracker;
> +#endif
> +};
> +
> +#ifdef CONFIG_DRM_DISPLAY_DP_TUNNEL
> +
> +struct drm_dp_tunnel *
> +drm_dp_tunnel_get_untracked(struct drm_dp_tunnel *tunnel);
> +void drm_dp_tunnel_put_untracked(struct drm_dp_tunnel *tunnel);
> +
> +#ifdef CONFIG_DRM_DISPLAY_DEBUG_DP_TUNNEL_STATE
> +struct drm_dp_tunnel *
> +drm_dp_tunnel_get(struct drm_dp_tunnel *tunnel, struct ref_tracker **tracker);
> +
> +void
> +drm_dp_tunnel_put(struct drm_dp_tunnel *tunnel, struct ref_tracker **tracker);
> +#else
> +#define drm_dp_tunnel_get(tunnel, tracker) \
> + drm_dp_tunnel_get_untracked(tunnel)
> +
> +#define drm_dp_tunnel_put(tunnel, tracker) \
> + drm_dp_tunnel_put_untracked(tunnel)
> +
> +#endif
> +
> +static inline void drm_dp_tunnel_ref_get(struct drm_dp_tunnel *tunnel,
> + struct drm_dp_tunnel_ref *tunnel_ref)
> +{
> + tunnel_ref->tunnel = drm_dp_tunnel_get(tunnel, &tunnel_ref->tracker);
> +}
> +
> +static inline void drm_dp_tunnel_ref_put(struct drm_dp_tunnel_ref *tunnel_ref)
> +{
> + drm_dp_tunnel_put(tunnel_ref->tunnel, &tunnel_ref->tracker);
> +}
> +
> +struct drm_dp_tunnel *
> +drm_dp_tunnel_detect(struct drm_dp_tunnel_mgr *mgr,
> + struct drm_dp_aux *aux);
> +int drm_dp_tunnel_destroy(struct drm_dp_tunnel *tunnel);
> +
> +int drm_dp_tunnel_enable_bw_alloc(struct drm_dp_tunnel *tunnel);
> +int drm_dp_tunnel_disable_bw_alloc(struct drm_dp_tunnel *tunnel);
> +bool drm_dp_tunnel_bw_alloc_is_enabled(const struct drm_dp_tunnel *tunnel);
> +int drm_dp_tunnel_alloc_bw(struct drm_dp_tunnel *tunnel, int bw);
> +int drm_dp_tunnel_check_state(struct drm_dp_tunnel *tunnel);
> +int drm_dp_tunnel_update_state(struct drm_dp_tunnel *tunnel);
> +
> +void drm_dp_tunnel_set_io_error(struct drm_dp_tunnel *tunnel);
> +
> +int drm_dp_tunnel_handle_irq(struct drm_dp_tunnel_mgr *mgr,
> + struct drm_dp_aux *aux);
> +
> +int drm_dp_tunnel_max_dprx_rate(const struct drm_dp_tunnel *tunnel);
> +int drm_dp_tunnel_max_dprx_lane_count(const struct drm_dp_tunnel *tunnel);
> +int drm_dp_tunnel_available_bw(const struct drm_dp_tunnel *tunnel);
> +
> +const char *drm_dp_tunnel_name(const struct drm_dp_tunnel *tunnel);
> +
> +struct drm_dp_tunnel_state *
> +drm_dp_tunnel_atomic_get_state(struct drm_atomic_state *state,
> + struct drm_dp_tunnel *tunnel);
> +struct drm_dp_tunnel_state *
> +drm_dp_tunnel_atomic_get_new_state(struct drm_atomic_state *state,
> + const struct drm_dp_tunnel *tunnel);
> +
> +void drm_dp_tunnel_atomic_clear_state(struct drm_dp_tunnel_state *tunnel_state);
> +
> +int drm_dp_tunnel_atomic_set_stream_bw(struct drm_atomic_state *state,
> + struct drm_dp_tunnel *tunnel,
> + u8 stream_id, int bw);
> +int drm_dp_tunnel_atomic_get_group_streams_in_state(struct drm_atomic_state *state,
> + const struct drm_dp_tunnel *tunnel,
> + u32 *stream_mask);
> +
> +int drm_dp_tunnel_atomic_check_stream_bws(struct drm_atomic_state *state,
> + u32 *failed_stream_mask);
> +
> +int drm_dp_tunnel_atomic_get_tunnel_bw(const struct drm_dp_tunnel_state *tunnel_state);
> +
> +struct drm_dp_tunnel_mgr *
> +drm_dp_tunnel_mgr_create(struct drm_device *dev, int max_group_count);
> +void drm_dp_tunnel_mgr_destroy(struct drm_dp_tunnel_mgr *mgr);
> +
> +#else
> +
> +static inline struct drm_dp_tunnel *
> +drm_dp_tunnel_get_untracked(struct drm_dp_tunnel *tunnel)
> +{
> + return NULL;
> +}
> +
> +static inline void
> +drm_dp_tunnel_put_untracked(struct drm_dp_tunnel *tunnel) {}
> +
> +static inline struct drm_dp_tunnel *
> +drm_dp_tunnel_get(struct drm_dp_tunnel *tunnel, struct ref_tracker **tracker)
> +{
> + return NULL;
> +}
> +
> +static inline void
> +drm_dp_tunnel_put(struct drm_dp_tunnel *tunnel, struct ref_tracker **tracker) {}
> +
> +static inline void drm_dp_tunnel_ref_get(struct drm_dp_tunnel *tunnel,
> + struct drm_dp_tunnel_ref *tunnel_ref) {}
> +static inline void drm_dp_tunnel_ref_put(struct drm_dp_tunnel_ref *tunnel_ref) {}
> +
> +static inline struct drm_dp_tunnel *
> +drm_dp_tunnel_detect(struct drm_dp_tunnel_mgr *mgr,
> + struct drm_dp_aux *aux)
> +{
> + return ERR_PTR(-EOPNOTSUPP);
> +}
> +
> +static inline int
> +drm_dp_tunnel_destroy(struct drm_dp_tunnel *tunnel)
> +{
> + return 0;
> +}
> +
> +static inline int drm_dp_tunnel_enable_bw_alloc(struct drm_dp_tunnel *tunnel)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline int drm_dp_tunnel_disable_bw_alloc(struct drm_dp_tunnel *tunnel)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline bool drm_dp_tunnel_bw_alloc_is_enabled(const struct drm_dp_tunnel *tunnel)
> +{
> + return false;
> +}
> +
> +static inline int
> +drm_dp_tunnel_alloc_bw(struct drm_dp_tunnel *tunnel, int bw)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline int
> +drm_dp_tunnel_check_state(struct drm_dp_tunnel *tunnel)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline int
> +drm_dp_tunnel_update_state(struct drm_dp_tunnel *tunnel)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline void drm_dp_tunnel_set_io_error(struct drm_dp_tunnel *tunnel) {}
> +static inline int
> +drm_dp_tunnel_handle_irq(struct drm_dp_tunnel_mgr *mgr,
> + struct drm_dp_aux *aux)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline int
> +drm_dp_tunnel_max_dprx_rate(const struct drm_dp_tunnel *tunnel)
> +{
> + return 0;
> +}
> +
> +static inline int
> +drm_dp_tunnel_max_dprx_lane_count(const struct drm_dp_tunnel *tunnel)
> +{
> + return 0;
> +}
> +
> +static inline int
> +drm_dp_tunnel_available_bw(const struct drm_dp_tunnel *tunnel)
> +{
> + return -1;
> +}
> +
> +static inline const char *
> +drm_dp_tunnel_name(const struct drm_dp_tunnel *tunnel)
> +{
> + return NULL;
> +}
> +
> +static inline struct drm_dp_tunnel_state *
> +drm_dp_tunnel_atomic_get_state(struct drm_atomic_state *state,
> + struct drm_dp_tunnel *tunnel)
> +{
> + return ERR_PTR(-EOPNOTSUPP);
> +}
> +
> +static inline struct drm_dp_tunnel_state *
> +drm_dp_tunnel_atomic_get_new_state(struct drm_atomic_state *state,
> + const struct drm_dp_tunnel *tunnel)
> +{
> + return ERR_PTR(-EOPNOTSUPP);
> +}
> +
> +static inline void
> +drm_dp_tunnel_atomic_clear_state(struct drm_dp_tunnel_state *tunnel_state) {}
> +
> +static inline int
> +drm_dp_tunnel_atomic_set_stream_bw(struct drm_atomic_state *state,
> + struct drm_dp_tunnel *tunnel,
> + u8 stream_id, int bw)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline int
> +drm_dp_tunnel_atomic_get_group_streams_in_state(struct drm_atomic_state *state,
> + const struct drm_dp_tunnel *tunnel,
> + u32 *stream_mask)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline int
> +drm_dp_tunnel_atomic_check_stream_bws(struct drm_atomic_state *state,
> + u32 *failed_stream_mask)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline int
> +drm_dp_tunnel_atomic_get_tunnel_bw(const struct drm_dp_tunnel_state *tunnel_state)
> +{
> + return 0;
> +}
> +
> +static inline struct drm_dp_tunnel_mgr *
> +drm_dp_tunnel_mgr_create(struct drm_device *dev, int max_group_count)
> +{
> + return ERR_PTR(-EOPNOTSUPP);
> +}
> +
> +static inline
> +void drm_dp_tunnel_mgr_destroy(struct drm_dp_tunnel_mgr *mgr) {}
> +
> +
> +#endif /* CONFIG_DRM_DISPLAY_DP_TUNNEL */
> +
> +#endif /* __DRM_DP_TUNNEL_H__ */
> --
> 2.39.2
--
Ville Syrjälä
Intel
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