On Tue, 2024-01-23 at 12:28 +0200, Imre Deak wrote:
> Add support for Display Port DP tunneling. For now this includes the
> support for Bandwidth Allocation Mode, leaving adding Panel Replay
> support for later.
>
> BWA allows using displays that share the same (Thunderbolt) link with
> their maximum resolution. Atm, this may not be possible due to the
> coarse granularity of partitioning the link BW among the displays on
> the
> link: the BW allocation policy is in a SW/FW/HW component on the link
> (on Thunderbolt it's the SW or FW Connection Manager), independent of
> the driver. This policy will set the DPRX maximum rate and lane count
> DPCD registers the GFX driver will see (0x00000, 0x00001, 0x02200,
> 0x02201) based on the available link BW.
>
> The granularity of the current BW allocation policy is course, based
> on
> the required link rate in the 1.62Gbs..8.1Gbps range and it may
> prevent
> using higher resolutions all together: the display connected first
> will
> get a share of the link BW which corresponds to its full DPRX
> capability
> (regardless of the actual mode it uses). A subsequent display
> connected
> will only get the remaining BW, which could be well below its full
> capability.
>
> BWA solves the above course granularity (reducing it to a
> 250Mbs..1Gps
> range) and first-come/first-served issues by letting the driver
> request
> the BW for each display on a link which reflects the actual modes the
> displays use.
>
> This patch adds the DRM core helper functions, while a follow-up
> change
> in the patchset takes them into use in the i915 driver.
>
> Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
> ---
> drivers/gpu/drm/display/Kconfig | 17 +
> drivers/gpu/drm/display/Makefile | 2 +
> drivers/gpu/drm/display/drm_dp_tunnel.c | 1715
> +++++++++++++++++++++++
> include/drm/display/drm_dp.h | 60 +
> include/drm/display/drm_dp_tunnel.h | 270 ++++
> 5 files changed, 2064 insertions(+)
> create mode 100644 drivers/gpu/drm/display/drm_dp_tunnel.c
> create mode 100644 include/drm/display/drm_dp_tunnel.h
>
> diff --git a/drivers/gpu/drm/display/Kconfig
> b/drivers/gpu/drm/display/Kconfig
> index 09712b88a5b83..b024a84b94c1c 100644
> --- a/drivers/gpu/drm/display/Kconfig
> +++ b/drivers/gpu/drm/display/Kconfig
> @@ -17,6 +17,23 @@ config DRM_DISPLAY_DP_HELPER
> help
> DRM display helpers for DisplayPort.
>
> +config DRM_DISPLAY_DP_TUNNEL
> + bool
> + select DRM_DISPLAY_DP_HELPER
> + help
> + Enable support for DisplayPort tunnels.
> +
> +config DRM_DISPLAY_DEBUG_DP_TUNNEL_STATE
> + bool "Enable debugging the DP tunnel state"
> + depends on REF_TRACKER
> + depends on DRM_DISPLAY_DP_TUNNEL
> + depends on DEBUG_KERNEL
> + depends on EXPERT
> + help
> + Enables debugging the DP tunnel manager's status.
> +
> + If in doubt, say "N".
> +
> config DRM_DISPLAY_HDCP_HELPER
> bool
> depends on DRM_DISPLAY_HELPER
> diff --git a/drivers/gpu/drm/display/Makefile
> b/drivers/gpu/drm/display/Makefile
> index 17ac4a1006a80..7ca61333c6696 100644
> --- a/drivers/gpu/drm/display/Makefile
> +++ b/drivers/gpu/drm/display/Makefile
> @@ -8,6 +8,8 @@ drm_display_helper-$(CONFIG_DRM_DISPLAY_DP_HELPER) +=
> \
> drm_dp_helper.o \
> drm_dp_mst_topology.o \
> drm_dsc_helper.o
> +drm_display_helper-$(CONFIG_DRM_DISPLAY_DP_TUNNEL) += \
> + drm_dp_tunnel.o
> drm_display_helper-$(CONFIG_DRM_DISPLAY_HDCP_HELPER) +=
> drm_hdcp_helper.o
> drm_display_helper-$(CONFIG_DRM_DISPLAY_HDMI_HELPER) += \
> drm_hdmi_helper.o \
> diff --git a/drivers/gpu/drm/display/drm_dp_tunnel.c
> b/drivers/gpu/drm/display/drm_dp_tunnel.c
> new file mode 100644
> index 0000000000000..58f6330db7d9d
> --- /dev/null
> +++ b/drivers/gpu/drm/display/drm_dp_tunnel.c
> @@ -0,0 +1,1715 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2023 Intel Corporation
> + */
> +
> +#include <linux/ref_tracker.h>
> +#include <linux/types.h>
> +
> +#include <drm/drm_atomic_state_helper.h>
> +
> +#include <drm/drm_atomic.h>
> +#include <drm/drm_print.h>
> +#include <drm/display/drm_dp.h>
> +#include <drm/display/drm_dp_helper.h>
> +#include <drm/display/drm_dp_tunnel.h>
> +
> +#define to_group(__private_obj) \
> + container_of(__private_obj, struct drm_dp_tunnel_group, base)
> +
> +#define to_group_state(__private_state) \
> + container_of(__private_state, struct
> drm_dp_tunnel_group_state, base)
> +
> +#define is_dp_tunnel_private_obj(__obj) \
> + ((__obj)->funcs == &tunnel_group_funcs)
> +
> +#define for_each_new_group_in_state(__state, __new_group_state, __i)
> \
> + for ((__i) = 0; \
> + (__i) < (__state)->num_private_objs; \
> + (__i)++) \
> + for_each_if ((__state)->private_objs[__i].ptr && \
> + is_dp_tunnel_private_obj((__state)-
> >private_objs[__i].ptr) && \
> + ((__new_group_state) = \
> + to_group_state((__state)-
> >private_objs[__i].new_state), 1))
> +
> +#define for_each_old_group_in_state(__state, __old_group_state, __i)
> \
> + for ((__i) = 0; \
> + (__i) < (__state)->num_private_objs; \
> + (__i)++) \
> + for_each_if ((__state)->private_objs[__i].ptr && \
> + is_dp_tunnel_private_obj((__state)-
> >private_objs[__i].ptr) && \
> + ((__old_group_state) = \
> + to_group_state((__state)-
> >private_objs[__i].old_state), 1))
> +
> +#define for_each_tunnel_in_group(__group, __tunnel) \
> + list_for_each_entry(__tunnel, &(__group)->tunnels, node)
> +
> +#define for_each_tunnel_state(__group_state, __tunnel_state) \
> + list_for_each_entry(__tunnel_state, &(__group_state)-
> >tunnel_states, node)
> +
> +#define for_each_tunnel_state_safe(__group_state, __tunnel_state,
> __tunnel_state_tmp) \
> + list_for_each_entry_safe(__tunnel_state, __tunnel_state_tmp,
> \
> + &(__group_state)->tunnel_states,
> node)
> +
> +#define kbytes_to_mbits(__kbytes) \
> + DIV_ROUND_UP((__kbytes) * 8, 1000)
> +
> +#define DPTUN_BW_ARG(__bw) ((__bw) < 0 ? (__bw) :
> kbytes_to_mbits(__bw))
> +
> +#define __tun_prn(__tunnel, __level, __type, __fmt, ...) \
> + drm_##__level##__type((__tunnel)->group->mgr->dev, \
> + "[DPTUN %s][%s] " __fmt, \
> + drm_dp_tunnel_name(__tunnel), \
> + (__tunnel)->aux->name, ## \
> + __VA_ARGS__)
> +
> +#define tun_dbg(__tunnel, __fmt, ...) \
> + __tun_prn(__tunnel, dbg, _kms, __fmt, ## __VA_ARGS__)
> +
> +#define tun_dbg_stat(__tunnel, __err, __fmt, ...) do { \
> + if (__err) \
> + __tun_prn(__tunnel, dbg, _kms, __fmt " (Failed, err:
> %pe)\n", \
> + ## __VA_ARGS__, ERR_PTR(__err)); \
> + else \
> + __tun_prn(__tunnel, dbg, _kms, __fmt " (Ok)\n", \
> + ## __VA_ARGS__); \
> +} while (0)
> +
> +#define tun_dbg_atomic(__tunnel, __fmt, ...) \
> + __tun_prn(__tunnel, dbg, _atomic, __fmt, ## __VA_ARGS__)
> +
> +#define tun_grp_dbg(__group, __fmt, ...) \
> + drm_dbg_kms((__group)->mgr->dev, \
> + "[DPTUN %s] " __fmt, \
> + drm_dp_tunnel_group_name(__group), ## \
> + __VA_ARGS__)
> +
> +#define DP_TUNNELING_BASE DP_TUNNELING_OUI
> +
> +#define __DPTUN_REG_RANGE(start, size) \
> + GENMASK_ULL(start + size - 1, start)
> +
> +#define DPTUN_REG_RANGE(addr, size) \
> + __DPTUN_REG_RANGE((addr) - DP_TUNNELING_BASE, size)
> +
> +#define DPTUN_REG(addr) DPTUN_REG_RANGE(addr, 1)
> +
> +#define DPTUN_INFO_REG_MASK ( \
> + DPTUN_REG_RANGE(DP_TUNNELING_OUI, DP_TUNNELING_OUI_BYTES) | \
> + DPTUN_REG_RANGE(DP_TUNNELING_DEV_ID,
> DP_TUNNELING_DEV_ID_BYTES) | \
> + DPTUN_REG(DP_TUNNELING_HW_REV) | \
> + DPTUN_REG(DP_TUNNELING_SW_REV_MAJOR) | \
> + DPTUN_REG(DP_TUNNELING_SW_REV_MINOR) | \
> + DPTUN_REG(DP_TUNNELING_CAPABILITIES) | \
> + DPTUN_REG(DP_IN_ADAPTER_INFO) | \
> + DPTUN_REG(DP_USB4_DRIVER_ID) | \
> + DPTUN_REG(DP_USB4_DRIVER_BW_CAPABILITY) | \
> + DPTUN_REG(DP_IN_ADAPTER_TUNNEL_INFORMATION) | \
> + DPTUN_REG(DP_BW_GRANULARITY) | \
> + DPTUN_REG(DP_ESTIMATED_BW) | \
> + DPTUN_REG(DP_ALLOCATED_BW) | \
> + DPTUN_REG(DP_TUNNELING_MAX_LINK_RATE) | \
> + DPTUN_REG(DP_TUNNELING_MAX_LANE_COUNT) | \
> + DPTUN_REG(DP_DPTX_BW_ALLOCATION_MODE_CONTROL))
> +
> +static const DECLARE_BITMAP(dptun_info_regs, 64) = {
> + DPTUN_INFO_REG_MASK & -1UL,
> +#if BITS_PER_LONG == 32
> + DPTUN_INFO_REG_MASK >> 32,
> +#endif
> +};
> +
> +struct drm_dp_tunnel_regs {
> + u8 buf[HWEIGHT64(DPTUN_INFO_REG_MASK)];
> +};
> +
> +struct drm_dp_tunnel_group;
> +
> +struct drm_dp_tunnel {
> + struct drm_dp_tunnel_group *group;
> +
> + struct list_head node;
> +
> + struct kref kref;
> +#ifdef CONFIG_DRM_DISPLAY_DEBUG_DP_TUNNEL_STATE
> + struct ref_tracker *tracker;
> +#endif
> + struct drm_dp_aux *aux;
> + char name[8];
> +
> + int bw_granularity;
> + int estimated_bw;
> + int allocated_bw;
> +
> + int max_dprx_rate;
> + u8 max_dprx_lane_count;
> +
> + u8 adapter_id;
> +
> + bool bw_alloc_supported:1;
> + bool bw_alloc_enabled:1;
> + bool has_io_error:1;
> + bool destroyed:1;
> +};
> +
> +struct drm_dp_tunnel_group_state;
> +
> +struct drm_dp_tunnel_state {
> + struct drm_dp_tunnel_group_state *group_state;
> +
> + struct drm_dp_tunnel_ref tunnel_ref;
> +
> + struct list_head node;
> +
> + u32 stream_mask;
I'm wondering if drm_dp_tunnel_state can really contain several streams
and what kind of scenario this would be? From i915 point of view I
would understand that several pipes are routed to DP tunnel. Is it
bigjoiner case?
BR,
Jouni Högander
> + int *stream_bw;
> +};
> +
> +struct drm_dp_tunnel_group_state {
> + struct drm_private_state base;
> +
> + struct list_head tunnel_states;
> +};
> +
> +struct drm_dp_tunnel_group {
> + struct drm_private_obj base;
> + struct drm_dp_tunnel_mgr *mgr;
> +
> + struct list_head tunnels;
> +
> + int available_bw; /* available BW including the
> allocated_bw of all tunnels */
> + int drv_group_id;
> +
> + char name[8];
> +
> + bool active:1;
> +};
> +
> +struct drm_dp_tunnel_mgr {
> + struct drm_device *dev;
> +
> + int group_count;
> + struct drm_dp_tunnel_group *groups;
> + wait_queue_head_t bw_req_queue;
> +
> +#ifdef CONFIG_DRM_DISPLAY_DEBUG_DP_TUNNEL_STATE
> + struct ref_tracker_dir ref_tracker;
> +#endif
> +};
> +
> +static int next_reg_area(int *offset)
> +{
> + *offset = find_next_bit(dptun_info_regs, 64, *offset);
> +
> + return find_next_zero_bit(dptun_info_regs, 64, *offset + 1) -
> *offset;
> +}
> +
> +#define tunnel_reg_ptr(__regs, __address) ({ \
> + WARN_ON(!test_bit((__address) - DP_TUNNELING_BASE,
> dptun_info_regs)); \
> + &(__regs)->buf[bitmap_weight(dptun_info_regs, (__address) -
> DP_TUNNELING_BASE)]; \
> +})
> +
> +static int read_tunnel_regs(struct drm_dp_aux *aux, struct
> drm_dp_tunnel_regs *regs)
> +{
> + int offset = 0;
> + int len;
> +
> + while ((len = next_reg_area(&offset))) {
> + int address = DP_TUNNELING_BASE + offset;
> +
> + if (drm_dp_dpcd_read(aux, address,
> tunnel_reg_ptr(regs, address), len) < 0)
> + return -EIO;
> +
> + offset += len;
> + }
> +
> + return 0;
> +}
> +
> +static u8 tunnel_reg(const struct drm_dp_tunnel_regs *regs, int
> address)
> +{
> + return *tunnel_reg_ptr(regs, address);
> +}
> +
> +static int tunnel_reg_drv_group_id(const struct drm_dp_tunnel_regs
> *regs)
> +{
> + int drv_id = tunnel_reg(regs, DP_USB4_DRIVER_ID) &
> DP_USB4_DRIVER_ID_MASK;
> + int group_id = tunnel_reg(regs,
> DP_IN_ADAPTER_TUNNEL_INFORMATION) & DP_GROUP_ID_MASK;
> +
> + if (!group_id)
> + return 0;
> +
> + return (drv_id << DP_GROUP_ID_BITS) | group_id;
> +}
> +
> +/* Return granularity in kB/s units */
> +static int tunnel_reg_bw_granularity(const struct drm_dp_tunnel_regs
> *regs)
> +{
> + int gr = tunnel_reg(regs, DP_BW_GRANULARITY) &
> DP_BW_GRANULARITY_MASK;
> +
> + WARN_ON(gr > 2);
> +
> + return (250000 << gr) / 8;
> +}
> +
> +static int tunnel_reg_max_dprx_rate(const struct drm_dp_tunnel_regs
> *regs)
> +{
> + u8 bw_code = tunnel_reg(regs, DP_TUNNELING_MAX_LINK_RATE);
> +
> + return drm_dp_bw_code_to_link_rate(bw_code);
> +}
> +
> +static int tunnel_reg_max_dprx_lane_count(const struct
> drm_dp_tunnel_regs *regs)
> +{
> + u8 lane_count = tunnel_reg(regs, DP_TUNNELING_MAX_LANE_COUNT)
> &
> + DP_TUNNELING_MAX_LANE_COUNT_MASK;
> +
> + return lane_count;
> +}
> +
> +static bool tunnel_reg_bw_alloc_supported(const struct
> drm_dp_tunnel_regs *regs)
> +{
> + u8 cap_mask = DP_TUNNELING_SUPPORT |
> DP_IN_BW_ALLOCATION_MODE_SUPPORT;
> +
> + if ((tunnel_reg(regs, DP_TUNNELING_CAPABILITIES) & cap_mask)
> != cap_mask)
> + return false;
> +
> + return tunnel_reg(regs, DP_USB4_DRIVER_BW_CAPABILITY) &
> + DP_USB4_DRIVER_BW_ALLOCATION_MODE_SUPPORT;
> +}
> +
> +static bool tunnel_reg_bw_alloc_enabled(const struct
> drm_dp_tunnel_regs *regs)
> +{
> + return tunnel_reg(regs, DP_DPTX_BW_ALLOCATION_MODE_CONTROL) &
> + DP_DISPLAY_DRIVER_BW_ALLOCATION_MODE_ENABLE;
> +}
> +
> +static int tunnel_group_drv_id(int drv_group_id)
> +{
> + return drv_group_id >> DP_GROUP_ID_BITS;
> +}
> +
> +static int tunnel_group_id(int drv_group_id)
> +{
> + return drv_group_id & DP_GROUP_ID_MASK;
> +}
> +
> +const char *drm_dp_tunnel_name(const struct drm_dp_tunnel *tunnel)
> +{
> + return tunnel->name;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_name);
> +
> +static const char *drm_dp_tunnel_group_name(const struct
> drm_dp_tunnel_group *group)
> +{
> + return group->name;
> +}
> +
> +static struct drm_dp_tunnel_group *
> +lookup_or_alloc_group(struct drm_dp_tunnel_mgr *mgr, int
> drv_group_id)
> +{
> + struct drm_dp_tunnel_group *group = NULL;
> + int i;
> +
> + for (i = 0; i < mgr->group_count; i++) {
> + /*
> + * A tunnel group with 0 group ID shouldn't have more
> than one
> + * tunnels.
> + */
> + if (tunnel_group_id(drv_group_id) &&
> + mgr->groups[i].drv_group_id == drv_group_id)
> + return &mgr->groups[i];
> +
> + if (!group && !mgr->groups[i].active)
> + group = &mgr->groups[i];
> + }
> +
> + if (!group) {
> + drm_dbg_kms(mgr->dev,
> + "DPTUN: Can't allocate more tunnel
> groups\n");
> + return NULL;
> + }
> +
> + group->drv_group_id = drv_group_id;
> + group->active = true;
> +
> + snprintf(group->name, sizeof(group->name), "%d:%d:*",
> + tunnel_group_drv_id(drv_group_id) & ((1 <<
> DP_GROUP_ID_BITS) - 1),
> + tunnel_group_id(drv_group_id) & ((1 <<
> DP_USB4_DRIVER_ID_BITS) - 1));
> +
> + return group;
> +}
> +
> +static void free_group(struct drm_dp_tunnel_group *group)
> +{
> + struct drm_dp_tunnel_mgr *mgr = group->mgr;
> +
> + if (drm_WARN_ON(mgr->dev, !list_empty(&group->tunnels)))
> + return;
> +
> + group->drv_group_id = 0;
> + group->available_bw = -1;
> + group->active = false;
> +}
> +
> +static struct drm_dp_tunnel *
> +tunnel_get(struct drm_dp_tunnel *tunnel)
> +{
> + kref_get(&tunnel->kref);
> +
> + return tunnel;
> +}
> +
> +static void free_tunnel(struct kref *kref)
> +{
> + struct drm_dp_tunnel *tunnel = container_of(kref,
> typeof(*tunnel), kref);
> + struct drm_dp_tunnel_group *group = tunnel->group;
> +
> + list_del(&tunnel->node);
> + if (list_empty(&group->tunnels))
> + free_group(group);
> +
> + kfree(tunnel);
> +}
> +
> +static void tunnel_put(struct drm_dp_tunnel *tunnel)
> +{
> + kref_put(&tunnel->kref, free_tunnel);
> +}
> +
> +#ifdef CONFIG_DRM_DISPLAY_DEBUG_DP_TUNNEL_STATE
> +static void track_tunnel_ref(struct drm_dp_tunnel *tunnel,
> + struct ref_tracker **tracker)
> +{
> + ref_tracker_alloc(&tunnel->group->mgr->ref_tracker,
> + tracker, GFP_KERNEL);
> +}
> +
> +static void untrack_tunnel_ref(struct drm_dp_tunnel *tunnel,
> + struct ref_tracker **tracker)
> +{
> + ref_tracker_free(&tunnel->group->mgr->ref_tracker,
> + tracker);
> +}
> +
> +struct drm_dp_tunnel *
> +drm_dp_tunnel_get_untracked(struct drm_dp_tunnel *tunnel)
> +{
> + track_tunnel_ref(tunnel, NULL);
> +
> + return tunnel_get(tunnel);
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_get_untracked);
> +
> +void drm_dp_tunnel_put_untracked(struct drm_dp_tunnel *tunnel)
> +{
> + tunnel_put(tunnel);
> + untrack_tunnel_ref(tunnel, NULL);
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_put_untracked);
> +
> +struct drm_dp_tunnel *
> +drm_dp_tunnel_get(struct drm_dp_tunnel *tunnel,
> + struct ref_tracker **tracker)
> +{
> + track_tunnel_ref(tunnel, tracker);
> +
> + return tunnel_get(tunnel);
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_get);
> +
> +void drm_dp_tunnel_put(struct drm_dp_tunnel *tunnel,
> + struct ref_tracker **tracker)
> +{
> + untrack_tunnel_ref(tunnel, tracker);
> + tunnel_put(tunnel);
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_put);
> +#else
> +#define track_tunnel_ref(tunnel, tracker) do {} while (0)
> +#define untrack_tunnel_ref(tunnel, tracker) do {} while (0)
> +
> +struct drm_dp_tunnel *
> +drm_dp_tunnel_get_untracked(struct drm_dp_tunnel *tunnel)
> +{
> + return tunnel_get(tunnel);
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_get_untracked);
> +
> +void drm_dp_tunnel_put_untracked(struct drm_dp_tunnel *tunnel)
> +{
> + tunnel_put(tunnel);
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_put_untracked);
> +#endif
> +
> +static bool add_tunnel_to_group(struct drm_dp_tunnel_mgr *mgr,
> + int drv_group_id,
> + struct drm_dp_tunnel *tunnel)
> +{
> + struct drm_dp_tunnel_group *group =
> + lookup_or_alloc_group(mgr, drv_group_id);
> +
> + if (!group)
> + return false;
> +
> + tunnel->group = group;
> + list_add(&tunnel->node, &group->tunnels);
> +
> + return true;
> +}
> +
> +static struct drm_dp_tunnel *
> +create_tunnel(struct drm_dp_tunnel_mgr *mgr,
> + struct drm_dp_aux *aux,
> + const struct drm_dp_tunnel_regs *regs)
> +{
> + int drv_group_id = tunnel_reg_drv_group_id(regs);
> + struct drm_dp_tunnel *tunnel;
> +
> + tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
> + if (!tunnel)
> + return NULL;
> +
> + INIT_LIST_HEAD(&tunnel->node);
> +
> + kref_init(&tunnel->kref);
> +
> + tunnel->aux = aux;
> +
> + tunnel->adapter_id = tunnel_reg(regs, DP_IN_ADAPTER_INFO) &
> DP_IN_ADAPTER_NUMBER_MASK;
> +
> + snprintf(tunnel->name, sizeof(tunnel->name), "%d:%d:%d",
> + tunnel_group_drv_id(drv_group_id) & ((1 <<
> DP_GROUP_ID_BITS) - 1),
> + tunnel_group_id(drv_group_id) & ((1 <<
> DP_USB4_DRIVER_ID_BITS) - 1),
> + tunnel->adapter_id & ((1 <<
> DP_IN_ADAPTER_NUMBER_BITS) - 1));
> +
> + tunnel->bw_granularity = tunnel_reg_bw_granularity(regs);
> + tunnel->allocated_bw = tunnel_reg(regs, DP_ALLOCATED_BW) *
> + tunnel->bw_granularity;
> +
> + tunnel->bw_alloc_supported =
> tunnel_reg_bw_alloc_supported(regs);
> + tunnel->bw_alloc_enabled = tunnel_reg_bw_alloc_enabled(regs);
> +
> + if (!add_tunnel_to_group(mgr, drv_group_id, tunnel)) {
> + kfree(tunnel);
> +
> + return NULL;
> + }
> +
> + track_tunnel_ref(tunnel, &tunnel->tracker);
> +
> + return tunnel;
> +}
> +
> +static void destroy_tunnel(struct drm_dp_tunnel *tunnel)
> +{
> + untrack_tunnel_ref(tunnel, &tunnel->tracker);
> + tunnel_put(tunnel);
> +}
> +
> +void drm_dp_tunnel_set_io_error(struct drm_dp_tunnel *tunnel)
> +{
> + tunnel->has_io_error = true;
> +}
> +EXPORT_SYMBOL(drm_dp_tunnel_set_io_error);
> +
> +static char yes_no_chr(int val)
> +{
> + return val ? 'Y' : 'N';
> +}
> +
> +#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.
> + */
> +
> + 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),
> + 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;
> +}
> +
> +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(tun
> nel_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) {
> + *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__ */
