drm/atomic: Allow for holes in connector state, v2.

Because we record connector_mask using 1 << drm_connector_index now
the connector_mask should stay the same even when other connectors
are removed. This was not the case with MST, in that case when removing
a connector all other connectors may change their index.

This is fixed by waiting until the first get_connector_state to allocate
connector_state, and force reallocation when state is too small.

As a side effect connector arrays no longer have to be preallocated,
and can be allocated on first use which means a less allocations in
the page flip only path.

Changes since v1:
- Whitespace. (Ville)
- Call ida_remove when destroying the connector. (Ville)
- u32 alloc -> int. (Ville)

Fixes: 14de6c44d149 ("drm/atomic: Remove drm_atomic_connectors_for_crtc.")
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Lyude <cpaul@redhat.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 3f74193885f1ff1df95db09fa76e01174f6353b4..9a7b44616b552920b6ef8f62553bd791d36af935 100644 (file)
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -65,8 +65,6 @@ drm_atomic_state_init(struct drm_device *dev, struct drm_atomic_state *state)
         */
        state->allow_modeset = true;
 
-       state->num_connector = ACCESS_ONCE(dev->mode_config.num_connector);
-
        state->crtcs = kcalloc(dev->mode_config.num_crtc,
                               sizeof(*state->crtcs), GFP_KERNEL);
        if (!state->crtcs)
@@ -83,16 +81,6 @@ drm_atomic_state_init(struct drm_device *dev, struct drm_atomic_state *state)
                                      sizeof(*state->plane_states), GFP_KERNEL);
        if (!state->plane_states)
                goto fail;
-       state->connectors = kcalloc(state->num_connector,
-                                   sizeof(*state->connectors),
-                                   GFP_KERNEL);
-       if (!state->connectors)
-               goto fail;
-       state->connector_states = kcalloc(state->num_connector,
-                                         sizeof(*state->connector_states),
-                                         GFP_KERNEL);
-       if (!state->connector_states)
-               goto fail;
 
        state->dev = dev;
 
@@ -823,19 +811,27 @@ drm_atomic_get_connector_state(struct drm_atomic_state *state,
 
        index = drm_connector_index(connector);
 
-       /*
-        * Construction of atomic state updates can race with a connector
-        * hot-add which might overflow. In this case flip the table and just
-        * restart the entire ioctl - no one is fast enough to livelock a cpu
-        * with physical hotplug events anyway.
-        *
-        * Note that we only grab the indexes once we have the right lock to
-        * prevent hotplug/unplugging of connectors. So removal is no problem,
-        * at most the array is a bit too large.
-        */
        if (index >= state->num_connector) {
-               DRM_DEBUG_ATOMIC("Hot-added connector would overflow state array, restarting\n");
-               return ERR_PTR(-EAGAIN);
+               struct drm_connector **c;
+               struct drm_connector_state **cs;
+               int alloc = max(index + 1, config->num_connector);
+
+               c = krealloc(state->connectors, alloc * sizeof(*state->connectors), GFP_KERNEL);
+               if (!c)
+                       return ERR_PTR(-ENOMEM);
+
+               state->connectors = c;
+               memset(&state->connectors[state->num_connector], 0,
+                      sizeof(*state->connectors) * (alloc - state->num_connector));
+
+               cs = krealloc(state->connector_states, alloc * sizeof(*state->connector_states), GFP_KERNEL);
+               if (!cs)
+                       return ERR_PTR(-ENOMEM);
+
+               state->connector_states = cs;
+               memset(&state->connector_states[state->num_connector], 0,
+                      sizeof(*state->connector_states) * (alloc - state->num_connector));
+               state->num_connector = alloc;
        }
 
        if (state->connector_states[index])

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 7c523060a076f715746829004657b227a9308640..4f2d3e161593057bfff2b046c1b1f30a3cc90d41 100644 (file)
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1493,7 +1493,7 @@ void drm_atomic_helper_swap_state(struct drm_device *dev,
 {
        int i;
 
-       for (i = 0; i < dev->mode_config.num_connector; i++) {
+       for (i = 0; i < state->num_connector; i++) {
                struct drm_connector *connector = state->connectors[i];
 
                if (!connector)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index d40bab29747edb0ea989afd81b0e5b5102dfb555..f6191215b2cbc97c11fbfda5eeadb9f61b2387e8 100644 (file)
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -918,12 +918,19 @@ int drm_connector_init(struct drm_device *dev,
        connector->base.properties = &connector->properties;
        connector->dev = dev;
        connector->funcs = funcs;
+
+       connector->connector_id = ida_simple_get(&config->connector_ida, 0, 0, GFP_KERNEL);
+       if (connector->connector_id < 0) {
+               ret = connector->connector_id;
+               goto out_put;
+       }
+
        connector->connector_type = connector_type;
        connector->connector_type_id =
                ida_simple_get(connector_ida, 1, 0, GFP_KERNEL);
        if (connector->connector_type_id < 0) {
                ret = connector->connector_type_id;
-               goto out_put;
+               goto out_put_id;
        }
        connector->name =
                kasprintf(GFP_KERNEL, "%s-%d",
@@ -931,7 +938,7 @@ int drm_connector_init(struct drm_device *dev,
                          connector->connector_type_id);
        if (!connector->name) {
                ret = -ENOMEM;
-               goto out_put;
+               goto out_put_type_id;
        }
 
        INIT_LIST_HEAD(&connector->probed_modes);
@@ -959,7 +966,12 @@ int drm_connector_init(struct drm_device *dev,
        }
 
        connector->debugfs_entry = NULL;
-
+out_put_type_id:
+       if (ret)
+               ida_remove(connector_ida, connector->connector_type_id);
+out_put_id:
+       if (ret)
+               ida_remove(&config->connector_ida, connector->connector_id);
 out_put:
        if (ret)
                drm_mode_object_put(dev, &connector->base);
@@ -996,6 +1008,9 @@ void drm_connector_cleanup(struct drm_connector *connector)
        ida_remove(&drm_connector_enum_list[connector->connector_type].ida,
                   connector->connector_type_id);
 
+       ida_remove(&dev->mode_config.connector_ida,
+                  connector->connector_id);
+
        kfree(connector->display_info.bus_formats);
        drm_mode_object_put(dev, &connector->base);
        kfree(connector->name);
@@ -1012,32 +1027,6 @@ void drm_connector_cleanup(struct drm_connector *connector)
 }
 EXPORT_SYMBOL(drm_connector_cleanup);
 
-/**
- * drm_connector_index - find the index of a registered connector
- * @connector: connector to find index for
- *
- * Given a registered connector, return the index of that connector within a DRM
- * device's list of connectors.
- */
-unsigned int drm_connector_index(struct drm_connector *connector)
-{
-       unsigned int index = 0;
-       struct drm_connector *tmp;
-       struct drm_mode_config *config = &connector->dev->mode_config;
-
-       WARN_ON(!drm_modeset_is_locked(&config->connection_mutex));
-
-       drm_for_each_connector(tmp, connector->dev) {
-               if (tmp == connector)
-                       return index;
-
-               index++;
-       }
-
-       BUG();
-}
-EXPORT_SYMBOL(drm_connector_index);
-
 /**
  * drm_connector_register - register a connector
  * @connector: the connector to register
@@ -5789,6 +5778,7 @@ void drm_mode_config_init(struct drm_device *dev)
        INIT_LIST_HEAD(&dev->mode_config.plane_list);
        idr_init(&dev->mode_config.crtc_idr);
        idr_init(&dev->mode_config.tile_idr);
+       ida_init(&dev->mode_config.connector_ida);
 
        drm_modeset_lock_all(dev);
        drm_mode_create_standard_properties(dev);
@@ -5869,6 +5859,7 @@ void drm_mode_config_cleanup(struct drm_device *dev)
                crtc->funcs->destroy(crtc);
        }
 
+       ida_destroy(&dev->mode_config.connector_ida);
        idr_destroy(&dev->mode_config.tile_idr);
        idr_destroy(&dev->mode_config.crtc_idr);
        drm_modeset_lock_fini(&dev->mode_config.connection_mutex);

diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index c65a212db77e7a99b26735c262cb31a9b2504195..c5b4b81a831ba733bee1dc8aba8c9a3bb7341739 100644 (file)
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -1166,6 +1166,7 @@ struct drm_connector {
        struct drm_mode_object base;
 
        char *name;
+       int connector_id;
        int connector_type;
        int connector_type_id;
        bool interlace_allowed;
@@ -2047,6 +2048,7 @@ struct drm_mode_config {
        struct list_head fb_list;
 
        int num_connector;
+       struct ida connector_ida;
        struct list_head connector_list;
        int num_encoder;
        struct list_head encoder_list;
@@ -2200,7 +2202,11 @@ int drm_connector_register(struct drm_connector *connector);
 void drm_connector_unregister(struct drm_connector *connector);
 
 extern void drm_connector_cleanup(struct drm_connector *connector);
-extern unsigned int drm_connector_index(struct drm_connector *connector);
+static inline unsigned drm_connector_index(struct drm_connector *connector)
+{
+       return connector->connector_id;
+}
+
 /* helper to unplug all connectors from sysfs for device */
 extern void drm_connector_unplug_all(struct drm_device *dev);