[PATCH 03/29] drm/dp: Add support for DP tunneling
Imre Deak
imre.deak at intel.com
Wed Dec 20 00:53:42 UTC 2023
Signed-off-by: Imre Deak <imre.deak at intel.com>
---
drivers/gpu/drm/display/Makefile | 1 +
drivers/gpu/drm/display/drm_dp_tunnel.c | 1679 +++++++++++++++++++++++
include/drm/display/drm_dp_tunnel.h | 106 ++
3 files changed, 1786 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/Makefile b/drivers/gpu/drm/display/Makefile
index 17ac4a1006a80..9a1eaaa26628a 100644
--- a/drivers/gpu/drm/display/Makefile
+++ b/drivers/gpu/drm/display/Makefile
@@ -7,6 +7,7 @@ drm_display_helper-$(CONFIG_DRM_DISPLAY_DP_HELPER) += \
drm_dp_dual_mode_helper.o \
drm_dp_helper.o \
drm_dp_mst_topology.o \
+ drm_dp_tunnel.o \
drm_dsc_helper.o
drm_display_helper-$(CONFIG_DRM_DISPLAY_HDCP_HELPER) += drm_hdcp_helper.o
drm_display_helper-$(CONFIG_DRM_DISPLAY_HDMI_HELPER) += \
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..538b88c442db7
--- /dev/null
+++ b/drivers/gpu/drm/display/drm_dp_tunnel.c
@@ -0,0 +1,1679 @@
+// 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 DPTUN_BW_ARG(__bw) ((__bw) < 0 ? (__bw) : (__bw) * 8 / 1000)
+
+#define __tun_prn(__tunnel, __level, __type, __fmt, ...) \
+ drm_##__level##__type((__tunnel)->group->mgr->dev, \
+ "[%s][DPTUN %s]: " __fmt, \
+ (__tunnel)->aux->name, \
+ drm_dp_tunnel_name(__tunnel), ## \
+ __VA_ARGS__)
+
+#define tun_dbg(__tunnel, __fmt, ...) \
+ __tun_prn(__tunnel, dbg, _kms, __fmt, ## __VA_ARGS__)
+
+#define tun_dbg_atomic(__tunnel, __fmt, ...) \
+ __tun_prn(__tunnel, dbg, _atomic, __fmt, ## __VA_ARGS__)
+
+#define tun_err(__tunnel, __fmt, ...) \
+ __tun_prn(__tunnel, err,, __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 DPTUN_DEBUG_STATE
+ struct ref_tracker *tracker;
+#endif
+ struct drm_dp_aux *aux;
+ char name[8];
+
+ int bw_granularity;
+ 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;
+ 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 DPTUN_DEBUG_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,
+ bool *alloced)
+{
+ 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) {
+ *alloced = false;
+ 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;
+ }
+
+ *alloced = true;
+
+ 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));
+ group->name[sizeof(group->name) - 1] = '\0';
+
+ 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 DPTUN_DEBUG_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)
+{
+ tunnel_put(tunnel);
+ untrack_tunnel_ref(tunnel, tracker);
+}
+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)
+{
+ bool alloced;
+ struct drm_dp_tunnel_group *group =
+ lookup_or_alloc_group(mgr, drv_group_id, &alloced);
+
+ 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->name[sizeof(tunnel->name) - 1] = '\0';
+
+ tunnel->bw_granularity = tunnel_reg_bw_granularity(regs);
+ tunnel->max_dprx_rate = tunnel_reg_max_dprx_rate(regs);
+ tunnel->max_dprx_lane_count = tunnel_reg_max_dprx_lane_count(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);
+}
+
+static void set_tunnel_io_error(struct drm_dp_tunnel *tunnel)
+{
+ tunnel->has_io_error = true;
+}
+
+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) {
+ set_tunnel_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 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;
+
+ tun_dbg(tunnel, "Setting BW alloc mode to %s\n",
+ enable ? "enabled" : "disabled");
+
+ 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:
+ set_tunnel_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 < 0) {
+ set_bw_alloc_mode(tunnel, false);
+
+ goto out;
+ }
+
+ update_dprx_caps(tunnel, ®s);
+
+out:
+ tun_dbg(tunnel,
+ "Enabling BW alloc mode: %s (DPRX:%dx%d err:%d)\n",
+ !err ? "Ok" : "Failed",
+ tunnel->max_dprx_rate / 100, tunnel->max_dprx_lane_count,
+ err);
+
+ 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(tunnel,
+ "Disabling BW alloc mode: %s (err %d)\n",
+ !err ? "Ok" : "Failed",
+ err);
+
+ 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;
+
+ tun_dbg(tunnel, "Allocating %d/%d Mb/s for tunnel\n",
+ DPTUN_BW_ARG(request_bw * tunnel->bw_granularity),
+ DPTUN_BW_ARG(get_max_tunnel_bw(tunnel)));
+
+ /* 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(5000);
+
+ 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(tunnel, "Allocating %d/%d Mb/s for tunnel: %s (Group alloc:%d/%d Mb/s err:%d)\n",
+ DPTUN_BW_ARG(request_bw * tunnel->bw_granularity),
+ DPTUN_BW_ARG(get_max_tunnel_bw(tunnel)),
+ !err ? "Ok" : "Failed",
+ DPTUN_BW_ARG(group_allocated_bw(tunnel->group)),
+ DPTUN_BW_ARG(tunnel->group->available_bw),
+ err);
+
+ if (err == -EIO)
+ set_tunnel_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 calc_group_available_bw(const struct drm_dp_tunnel *tunnel, int estimated_bw)
+{
+ return group_allocated_bw(tunnel->group) -
+ tunnel->allocated_bw +
+ estimated_bw;
+}
+
+static int update_group_available_bw(struct drm_dp_tunnel *tunnel)
+{
+ struct drm_dp_tunnel *tunnel_iter;
+ int group_available_bw;
+ int estimated_bw;
+ bool changed;
+ u8 val;
+
+ if (drm_dp_dpcd_readb(tunnel->aux, DP_ESTIMATED_BW, &val) < 0) {
+ set_tunnel_io_error(tunnel);
+
+ return -EIO;
+ }
+
+ estimated_bw = val * tunnel->bw_granularity;
+
+ if (calc_group_available_bw(tunnel, estimated_bw) ==
+ tunnel->group->available_bw) {
+ tun_dbg(tunnel, "group available BW hasn't changed\n");
+
+ return 0;
+ }
+
+ tun_dbg(tunnel, "group available BW changed, updating\n");
+
+ for_each_tunnel_in_group(tunnel->group, tunnel_iter) {
+ if (tunnel_iter == tunnel)
+ continue;
+
+ if (check_tunnel(tunnel_iter) != 0 ||
+ !tunnel_iter->bw_alloc_enabled)
+ continue;
+
+ if (drm_dp_dpcd_probe(tunnel_iter->aux, DP_DPCD_REV) < 0) {
+ tun_dbg(tunnel, "probe failed, assume disconnected\n");
+ set_tunnel_io_error(tunnel_iter);
+ }
+ }
+
+ group_available_bw = calc_group_available_bw(tunnel, estimated_bw);
+
+ 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 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)
+ return 0;
+
+ if (drm_dp_dpcd_writeb(tunnel->aux, DP_TUNNELING_STATUS, val) < 0)
+ goto out_err;
+
+ return 1;
+
+out_err:
+ set_tunnel_io_error(tunnel);
+
+ return -EIO;
+}
+
+/**
+ * drm_dp_tunnel_update_state: Update DP tunnel SW state with the HW state
+ * @tunnel: Tunnel object
+ * @force_update: Force updating the state
+ *
+ * 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, bool force_update)
+{
+ 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 && !force_update)
+ return 0;
+
+ ret = read_and_verify_tunnel_regs(tunnel, ®s, 0);
+ if (ret < 0)
+ goto out;
+
+ if (update_dprx_caps(tunnel, ®s))
+ changed = true;
+
+ ret = update_group_available_bw(tunnel);
+ if (ret == 1)
+ changed = true;
+
+out:
+ tun_dbg(tunnel,
+ "Status update: %s (Changed:%c DPRX:%dx%d Tunnel alloc:%d/%d Group alloc:%d/%d Mb/s ret:%d)\n",
+ ret < 0 ? "Failed" : "Ok",
+ 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),
+ ret);
+
+ 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)
+{
+ if (tunnel->group->available_bw < 0)
+ return tunnel->group->available_bw;
+
+ return tunnel->group->available_bw * 8 / 10;
+}
+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_group_state *
+drm_dp_tunnel_atomic_get_new_group_state(struct drm_atomic_state *state,
+ const struct drm_dp_tunnel *tunnel)
+{
+ return (struct drm_dp_tunnel_group_state *)
+ drm_atomic_get_new_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;
+
+ 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);
+
+ tun_dbg_atomic(tunnel, "Adding DP tunnel state\n");
+
+ return tunnel_state;
+}
+
+void drm_dp_tunnel_atomic_clear_state(struct drm_dp_tunnel_state *tunnel_state)
+{
+ 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);
+}
+
+static int stream_id_to_idx(u32 stream_mask, u8 stream_id)
+{
+ return hweight32(stream_mask & (BIT(stream_id) - 1));
+}
+
+static int set_stream_bw(struct drm_dp_tunnel_state *tunnel_state,
+ u8 stream_id, int bw)
+{
+ struct drm_dp_tunnel *tunnel = tunnel_state->tunnel_ref.tunnel;
+ unsigned long old_mask = tunnel_state->stream_mask;
+
+ if (drm_WARN_ON(tunnel->group->mgr->dev,
+ stream_id > BITS_PER_TYPE(tunnel_state->stream_mask)))
+ return -EINVAL;
+
+ if (!test_bit(stream_id, &old_mask)) {
+ unsigned long new_mask = old_mask | BIT(stream_id);
+ int *new_bws;
+ int old_id;
+
+ new_bws = kcalloc(hweight32(new_mask), sizeof(*new_bws), GFP_KERNEL);
+ if (!new_bws)
+ return -ENOMEM;
+
+ for_each_set_bit(old_id, &old_mask, BITS_PER_TYPE(old_mask))
+ new_bws[stream_id_to_idx(new_mask, old_id)] =
+ tunnel_state->stream_bw[stream_id_to_idx(old_mask, old_id)];
+
+ kfree(tunnel_state->stream_bw);
+ tunnel_state->stream_bw = new_bws;
+ tunnel_state->stream_mask = new_mask;
+ }
+
+ tunnel_state->stream_bw[stream_id_to_idx(tunnel_state->stream_mask, stream_id)] = bw;
+
+ tun_dbg(tunnel,
+ "Required %d Mb/s for stream %d\n",
+ DPTUN_BW_ARG(bw), stream_id);
+
+ return 0;
+}
+
+#ifdef DPTUN_DEBUG_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
+
+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_new_group_state(state, tunnel);
+ struct drm_dp_tunnel_state *new_tunnel_state =
+ get_or_add_tunnel_state(new_group_state, tunnel);
+ int err;
+
+ if (drm_WARN_ON(state->dev, !new_tunnel_state))
+ return -EINVAL;
+
+ err = set_stream_bw(new_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 DPTUN_DEBUG_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 DPTUN_DEBUG_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_tunnel.h b/include/drm/display/drm_dp_tunnel.h
new file mode 100644
index 0000000000000..a85c3141ebc44
--- /dev/null
+++ b/include/drm/display/drm_dp_tunnel.h
@@ -0,0 +1,106 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#ifndef __DRM_DP_TUNNEL_H__
+#define __DRM_DP_TUNNEL_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;
+
+#define DPTUN_DEBUG_STATE 1
+
+struct drm_dp_tunnel_ref {
+ struct drm_dp_tunnel *tunnel;
+#ifdef DPTUN_DEBUG_STATE
+ struct ref_tracker *tracker;
+#endif
+};
+
+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 DPTUN_DEBUG_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, bool force);
+
+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);
+
+#endif
--
2.39.2
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