vulkan: Add EXT_acquire_xlib_display [v5]

This extension adds the ability to borrow an X RandR output for
temporary use directly by a Vulkan application. For DRM, we use the
Linux resource leasing mechanism.

v2:
	Clean up xlib_lease detection

	* Use separate temporary '_xlib_lease' variable to hold the
	  option value to avoid changin the type of a variable.

	* Use boolean expressions instead of additional if statements
	  to compute resulting with_xlib_lease value.

	* Simplify addition of VK_USE_PLATFORM_XLIB_XRANDR_KHR to
          vulkan_wsi_args

	  Suggested-by: Eric Engestrom <[email protected]>

	Move mode list from wsi_display to wsi_display_connector

	Fix scope for wsi_display_mode and wsi_display_connector allocs

	  Suggested-by: Jason Ekstrand <[email protected]>

v3:
	Adopt Jason Ekstrand's coding conventions

	Declare variables at first use, eliminate extra whitespace
	between types and names. Wrap lines to 80 columns.

	Explicitly forbid multiple DRM leases. Making the code support
	this looks tricky and will require additional thought.

	Use xcb_randr_output_t throughout the internals of the
	implementation. Convert at the public API
	(wsi_get_randr_output_display).

	Clean up check for usable active_crtc (possible when only the
	desired output is connected to the crtc).

	Suggested-by: Jason Ekstrand <[email protected]>

v4:
	Move output resource fetching closer to use in
	wsi_display_get_output. This simplifies the error returns in
	earlier parts of the code a bit.

	Return VK_ERROR_INITIALIZATION_FAILED from
	wsi_acquire_xlib_display. Jason says this is the right error
	message.

	Suggested-by: Jason Ekstrand <[email protected]>

v5:
	randr doesn't pass vscan over the wire, so we set vscan to 0
	for randr-acquired modes, and test wsi modes for vscan <= 1
	when comparing against randr modes.

    	Suggested-by: Jason Ekstrand <[email protected]>

Signed-off-by: Keith Packard <[email protected]>
Reviewed-by: Jason Ekstrand <[email protected]>

4 files changed, 515 insertions, 0 deletions

diff --git a/src/vulkan/Makefile.am b/src/vulkan/Makefile.am
index 352cfacab31..9deb6e18ff0 100644
--- a/src/vulkan/Makefile.am
+++ b/src/vulkan/Makefile.am
@@ -61,6 +61,11 @@ AM_CPPFLAGS += \
 VULKAN_WSI_SOURCES += $(VULKAN_WSI_DISPLAY_FILES)
 endif
 
+if HAVE_XLIB_LEASE
+AM_CPPFLAGS += \
+	-DVK_USE_PLATFORM_XLIB_XRANDR_EXT
+endif
+
 CLEANFILES = \
 	$(VULKAN_UTIL_GENERATED_FILES) \
 	$(VULKAN_WSI_WAYLAND_GENERATED_FILES)
diff --git a/src/vulkan/wsi/meson.build b/src/vulkan/wsi/meson.build
index 53306295ee3..3501a864e18 100644
--- a/src/vulkan/wsi/meson.build
+++ b/src/vulkan/wsi/meson.build
@@ -67,6 +67,11 @@ if with_platform_drm
   )
 endif
 
+if with_xlib_lease
+  vulkan_wsi_deps += dep_xcb_xrandr
+  vulkan_wsi_args += '-DVK_USE_PLATFORM_XLIB_XRANDR_EXT'
+endif
+
 libvulkan_wsi = static_library(
   'vulkan_wsi',
   files_vulkan_wsi,
diff --git a/src/vulkan/wsi/wsi_common_display.c b/src/vulkan/wsi/wsi_common_display.c
index d9569981ab5..4f52e8087a6 100644
--- a/src/vulkan/wsi/wsi_common_display.c
+++ b/src/vulkan/wsi/wsi_common_display.c
@@ -33,6 +33,10 @@
 #include <xf86drm.h>
 #include <xf86drmMode.h>
 #include <drm_fourcc.h>
+#ifdef VK_USE_PLATFORM_XLIB_XRANDR_EXT
+#include <xcb/randr.h>
+#include <X11/Xlib-xcb.h>
+#endif
 #include "util/hash_table.h"
 #include "util/list.h"
 
@@ -75,6 +79,9 @@ typedef struct wsi_display_connector {
    struct list_head             display_modes;
    wsi_display_mode             *current_mode;
    drmModeModeInfo              current_drm_mode;
+#ifdef VK_USE_PLATFORM_XLIB_XRANDR_EXT
+   xcb_randr_output_t           output;
+#endif
 } wsi_display_connector;
 
 struct wsi_display {
@@ -1491,5 +1498,486 @@ wsi_release_display(VkPhysicalDevice            physical_device,
       close(wsi->fd);
       wsi->fd = -1;
    }
+#ifdef VK_USE_PLATFORM_XLIB_XRANDR_EXT
+   wsi_display_connector_from_handle(display)->output = None;
+#endif
+
+   return VK_SUCCESS;
+}
+
+#ifdef VK_USE_PLATFORM_XLIB_XRANDR_EXT
+
+static struct wsi_display_connector *
+wsi_display_find_output(struct wsi_device *wsi_device,
+                        xcb_randr_output_t output)
+{
+   struct wsi_display *wsi =
+      (struct wsi_display *) wsi_device->wsi[VK_ICD_WSI_PLATFORM_DISPLAY];
+
+   wsi_for_each_connector(connector, wsi) {
+      if (connector->output == output)
+         return connector;
+   }
+
+   return NULL;
+}
+
+/*
+ * Given a RandR output, find the associated kernel connector_id by
+ * looking at the CONNECTOR_ID property provided by the X server
+ */
+
+static uint32_t
+wsi_display_output_to_connector_id(xcb_connection_t *connection,
+                                   xcb_atom_t *connector_id_atom_p,
+                                   xcb_randr_output_t output)
+{
+   uint32_t connector_id = 0;
+   xcb_atom_t connector_id_atom = *connector_id_atom_p;
+
+   if (connector_id_atom == 0) {
+   /* Go dig out the CONNECTOR_ID property */
+      xcb_intern_atom_cookie_t ia_c = xcb_intern_atom(connection,
+                                                          true,
+                                                          12,
+                                                          "CONNECTOR_ID");
+      xcb_intern_atom_reply_t *ia_r = xcb_intern_atom_reply(connection,
+                                                                 ia_c,
+                                                                 NULL);
+      if (ia_r) {
+         *connector_id_atom_p = connector_id_atom = ia_r->atom;
+         free(ia_r);
+      }
+   }
+
+   /* If there's an CONNECTOR_ID atom in the server, then there may be a
+    * CONNECTOR_ID property. Otherwise, there will not be and we don't even
+    * need to bother.
+    */
+   if (connector_id_atom) {
+
+      xcb_randr_query_version_cookie_t qv_c =
+         xcb_randr_query_version(connection, 1, 6);
+      xcb_randr_get_output_property_cookie_t gop_c =
+         xcb_randr_get_output_property(connection,
+                                       output,
+                                       connector_id_atom,
+                                       0,
+                                       0,
+                                       0xffffffffUL,
+                                       0,
+                                       0);
+      xcb_randr_query_version_reply_t *qv_r =
+         xcb_randr_query_version_reply(connection, qv_c, NULL);
+      free(qv_r);
+      xcb_randr_get_output_property_reply_t *gop_r =
+         xcb_randr_get_output_property_reply(connection, gop_c, NULL);
+      if (gop_r) {
+         if (gop_r->num_items == 1 && gop_r->format == 32)
+            memcpy(&connector_id, xcb_randr_get_output_property_data(gop_r), 4);
+         free(gop_r);
+      }
+   }
+   return connector_id;
+}
+
+static bool
+wsi_display_check_randr_version(xcb_connection_t *connection)
+{
+   xcb_randr_query_version_cookie_t qv_c =
+      xcb_randr_query_version(connection, 1, 6);
+   xcb_randr_query_version_reply_t *qv_r =
+      xcb_randr_query_version_reply(connection, qv_c, NULL);
+   bool ret = false;
+
+   if (!qv_r)
+      return false;
+
+   /* Check for version 1.6 or newer */
+   ret = (qv_r->major_version > 1 ||
+          (qv_r->major_version == 1 && qv_r->minor_version >= 6));
+
+   free(qv_r);
+   return ret;
+}
+
+/*
+ * Given a kernel connector id, find the associated RandR output using the
+ * CONNECTOR_ID property
+ */
+
+static xcb_randr_output_t
+wsi_display_connector_id_to_output(xcb_connection_t *connection,
+                                   uint32_t connector_id)
+{
+   if (!wsi_display_check_randr_version(connection))
+      return 0;
+
+   const xcb_setup_t *setup = xcb_get_setup(connection);
+
+   xcb_atom_t connector_id_atom = 0;
+   xcb_randr_output_t output = 0;
+
+   /* Search all of the screens for the provided output */
+   xcb_screen_iterator_t iter;
+   for (iter = xcb_setup_roots_iterator(setup);
+        output == 0 && iter.rem;
+        xcb_screen_next(&iter))
+   {
+      xcb_randr_get_screen_resources_cookie_t gsr_c =
+         xcb_randr_get_screen_resources(connection, iter.data->root);
+      xcb_randr_get_screen_resources_reply_t *gsr_r =
+         xcb_randr_get_screen_resources_reply(connection, gsr_c, NULL);
+
+      if (!gsr_r)
+         return 0;
+
+      xcb_randr_output_t *ro = xcb_randr_get_screen_resources_outputs(gsr_r);
+      int o;
+
+      for (o = 0; o < gsr_r->num_outputs; o++) {
+         if (wsi_display_output_to_connector_id(connection,
+                                                &connector_id_atom, ro[o])
+             == connector_id)
+         {
+            output = ro[o];
+            break;
+         }
+      }
+      free(gsr_r);
+   }
+   return output;
+}
+
+/*
+ * Given a RandR output, find out which screen it's associated with
+ */
+static xcb_window_t
+wsi_display_output_to_root(xcb_connection_t *connection,
+                           xcb_randr_output_t output)
+{
+   if (!wsi_display_check_randr_version(connection))
+      return 0;
+
+   const xcb_setup_t *setup = xcb_get_setup(connection);
+   xcb_window_t root = 0;
+
+   /* Search all of the screens for the provided output */
+   for (xcb_screen_iterator_t iter = xcb_setup_roots_iterator(setup);
+        root == 0 && iter.rem;
+        xcb_screen_next(&iter))
+   {
+      xcb_randr_get_screen_resources_cookie_t gsr_c =
+         xcb_randr_get_screen_resources(connection, iter.data->root);
+      xcb_randr_get_screen_resources_reply_t *gsr_r =
+         xcb_randr_get_screen_resources_reply(connection, gsr_c, NULL);
+
+      if (!gsr_r)
+         return 0;
+
+      xcb_randr_output_t *ro = xcb_randr_get_screen_resources_outputs(gsr_r);
+
+      for (int o = 0; o < gsr_r->num_outputs; o++) {
+         if (ro[o] == output) {
+            root = iter.data->root;
+            break;
+         }
+      }
+      free(gsr_r);
+   }
+   return root;
+}
+
+static bool
+wsi_display_mode_matches_x(struct wsi_display_mode *wsi,
+                           xcb_randr_mode_info_t *xcb)
+{
+   return wsi->clock == (xcb->dot_clock + 500) / 1000 &&
+      wsi->hdisplay == xcb->width &&
+      wsi->hsync_start == xcb->hsync_start &&
+      wsi->hsync_end == xcb->hsync_end &&
+      wsi->htotal == xcb->htotal &&
+      wsi->hskew == xcb->hskew &&
+      wsi->vdisplay == xcb->height &&
+      wsi->vsync_start == xcb->vsync_start &&
+      wsi->vsync_end == xcb->vsync_end &&
+      wsi->vtotal == xcb->vtotal &&
+      wsi->vscan <= 1 &&
+      wsi->flags == xcb->mode_flags;
+}
+
+static struct wsi_display_mode *
+wsi_display_find_x_mode(struct wsi_device *wsi_device,
+                        struct wsi_display_connector *connector,
+                        xcb_randr_mode_info_t *mode)
+{
+   wsi_for_each_display_mode(display_mode, connector) {
+      if (wsi_display_mode_matches_x(display_mode, mode))
+         return display_mode;
+   }
+   return NULL;
+}
+
+static VkResult
+wsi_display_register_x_mode(struct wsi_device *wsi_device,
+                            struct wsi_display_connector *connector,
+                            xcb_randr_mode_info_t *x_mode,
+                            bool preferred)
+{
+   struct wsi_display *wsi =
+      (struct wsi_display *) wsi_device->wsi[VK_ICD_WSI_PLATFORM_DISPLAY];
+   struct wsi_display_mode *display_mode =
+      wsi_display_find_x_mode(wsi_device, connector, x_mode);
+
+   if (display_mode) {
+      display_mode->valid = true;
+      return VK_SUCCESS;
+   }
+
+   display_mode = vk_zalloc(wsi->alloc, sizeof (struct wsi_display_mode),
+                            8, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
+   if (!display_mode)
+      return VK_ERROR_OUT_OF_HOST_MEMORY;
+
+   display_mode->connector = connector;
+   display_mode->valid = true;
+   display_mode->preferred = preferred;
+   display_mode->clock = (x_mode->dot_clock + 500) / 1000; /* kHz */
+   display_mode->hdisplay = x_mode->width;
+   display_mode->hsync_start = x_mode->hsync_start;
+   display_mode->hsync_end = x_mode->hsync_end;
+   display_mode->htotal = x_mode->htotal;
+   display_mode->hskew = x_mode->hskew;
+   display_mode->vdisplay = x_mode->height;
+   display_mode->vsync_start = x_mode->vsync_start;
+   display_mode->vsync_end = x_mode->vsync_end;
+   display_mode->vtotal = x_mode->vtotal;
+   display_mode->vscan = 0;
+   display_mode->flags = x_mode->mode_flags;
+
+   list_addtail(&display_mode->list, &connector->display_modes);
+   return VK_SUCCESS;
+}
+
+static struct wsi_display_connector *
+wsi_display_get_output(struct wsi_device *wsi_device,
+                       xcb_connection_t *connection,
+                       xcb_randr_output_t output)
+{
+   struct wsi_display *wsi =
+      (struct wsi_display *) wsi_device->wsi[VK_ICD_WSI_PLATFORM_DISPLAY];
+   struct wsi_display_connector *connector;
+   uint32_t connector_id;
+
+   xcb_window_t root = wsi_display_output_to_root(connection, output);
+   if (!root)
+      return NULL;
+
+   /* See if we already have a connector for this output */
+   connector = wsi_display_find_output(wsi_device, output);
+
+   if (!connector) {
+      xcb_atom_t connector_id_atom = 0;
+
+      /*
+       * Go get the kernel connector ID for this X output
+       */
+      connector_id = wsi_display_output_to_connector_id(connection,
+                                                        &connector_id_atom,
+                                                        output);
+
+      /* Any X server with lease support will have this atom */
+      if (!connector_id) {
+         return NULL;
+      }
+
+      /* See if we already have a connector for this id */
+      connector = wsi_display_find_connector(wsi_device, connector_id);
+
+      if (connector == NULL) {
+         connector = wsi_display_alloc_connector(wsi, connector_id);
+         if (!connector) {
+            return NULL;
+         }
+         list_addtail(&connector->list, &wsi->connectors);
+      }
+      connector->output = output;
+   }
+
+   xcb_randr_get_screen_resources_cookie_t src =
+      xcb_randr_get_screen_resources(connection, root);
+   xcb_randr_get_output_info_cookie_t oic =
+      xcb_randr_get_output_info(connection, output, XCB_CURRENT_TIME);
+   xcb_randr_get_screen_resources_reply_t *srr =
+      xcb_randr_get_screen_resources_reply(connection, src, NULL);
+   xcb_randr_get_output_info_reply_t *oir =
+      xcb_randr_get_output_info_reply(connection, oic, NULL);
+
+   if (oir && srr) {
+      /* Get X modes and add them */
+
+      connector->connected =
+         oir->connection != XCB_RANDR_CONNECTION_DISCONNECTED;
+
+      wsi_display_invalidate_connector_modes(wsi_device, connector);
+
+      xcb_randr_mode_t *x_modes = xcb_randr_get_output_info_modes(oir);
+      for (int m = 0; m < oir->num_modes; m++) {
+         xcb_randr_mode_info_iterator_t i =
+            xcb_randr_get_screen_resources_modes_iterator(srr);
+         while (i.rem) {
+            xcb_randr_mode_info_t *mi = i.data;
+            if (mi->id == x_modes[m]) {
+               VkResult result = wsi_display_register_x_mode(
+                  wsi_device, connector, mi, m < oir->num_preferred);
+               if (result != VK_SUCCESS) {
+                  free(oir);
+                  free(srr);
+                  return NULL;
+               }
+               break;
+            }
+            xcb_randr_mode_info_next(&i);
+         }
+      }
+   }
+
+   free(oir);
+   free(srr);
+   return connector;
+}
+
+static xcb_randr_crtc_t
+wsi_display_find_crtc_for_output(xcb_connection_t *connection,
+                                 xcb_window_t root,
+                                 xcb_randr_output_t output)
+{
+   xcb_randr_get_screen_resources_cookie_t gsr_c =
+      xcb_randr_get_screen_resources(connection, root);
+   xcb_randr_get_screen_resources_reply_t *gsr_r =
+      xcb_randr_get_screen_resources_reply(connection, gsr_c, NULL);
+
+   if (!gsr_r)
+      return 0;
+
+   xcb_randr_crtc_t *rc = xcb_randr_get_screen_resources_crtcs(gsr_r);
+   xcb_randr_crtc_t idle_crtc = 0;
+   xcb_randr_crtc_t active_crtc = 0;
+
+   /* Find either a crtc already connected to the desired output or idle */
+   for (int c = 0; active_crtc == 0 && c < gsr_r->num_crtcs; c++) {
+      xcb_randr_get_crtc_info_cookie_t gci_c =
+         xcb_randr_get_crtc_info(connection, rc[c], gsr_r->config_timestamp);
+      xcb_randr_get_crtc_info_reply_t *gci_r =
+         xcb_randr_get_crtc_info_reply(connection, gci_c, NULL);
+
+      if (gci_r) {
+         if (gci_r->mode) {
+            int num_outputs = xcb_randr_get_crtc_info_outputs_length(gci_r);
+            xcb_randr_output_t *outputs =
+               xcb_randr_get_crtc_info_outputs(gci_r);
+
+            if (num_outputs == 1 && outputs[0] == output)
+               active_crtc = rc[c];
+
+         } else if (idle_crtc == 0) {
+            int num_possible = xcb_randr_get_crtc_info_possible_length(gci_r);
+            xcb_randr_output_t *possible =
+               xcb_randr_get_crtc_info_possible(gci_r);
+
+            for (int p = 0; p < num_possible; p++)
+               if (possible[p] == output) {
+                  idle_crtc = rc[c];
+                  break;
+               }
+         }
+         free(gci_r);
+      }
+   }
+   free(gsr_r);
+
+   if (active_crtc)
+      return active_crtc;
+   return idle_crtc;
+}
+
+VkResult
+wsi_acquire_xlib_display(VkPhysicalDevice physical_device,
+                         struct wsi_device *wsi_device,
+                         Display *dpy,
+                         VkDisplayKHR display)
+{
+   struct wsi_display *wsi =
+      (struct wsi_display *) wsi_device->wsi[VK_ICD_WSI_PLATFORM_DISPLAY];
+   xcb_connection_t *connection = XGetXCBConnection(dpy);
+   struct wsi_display_connector *connector =
+      wsi_display_connector_from_handle(display);
+   xcb_window_t root;
+
+   /* XXX no support for multiple leases yet */
+   if (wsi->fd >= 0)
+      return VK_ERROR_INITIALIZATION_FAILED;
+
+   if (!connector->output) {
+      connector->output = wsi_display_connector_id_to_output(connection,
+                                                             connector->id);
+
+      /* Check and see if we found the output */
+      if (!connector->output)
+         return VK_ERROR_INITIALIZATION_FAILED;
+   }
+
+   root = wsi_display_output_to_root(connection, connector->output);
+   if (!root)
+      return VK_ERROR_INITIALIZATION_FAILED;
+
+   xcb_randr_crtc_t crtc = wsi_display_find_crtc_for_output(connection,
+                                                            root,
+                                                            connector->output);
+
+   if (!crtc)
+      return VK_ERROR_INITIALIZATION_FAILED;
+
+   xcb_randr_lease_t lease = xcb_generate_id(connection);
+   xcb_randr_create_lease_cookie_t cl_c =
+      xcb_randr_create_lease(connection, root, lease, 1, 1,
+                             &crtc, &connector->output);
+   xcb_randr_create_lease_reply_t *cl_r =
+      xcb_randr_create_lease_reply(connection, cl_c, NULL);
+   if (!cl_r)
+      return VK_ERROR_INITIALIZATION_FAILED;
+
+   int fd = -1;
+   if (cl_r->nfd > 0) {
+      int *rcl_f = xcb_randr_create_lease_reply_fds(connection, cl_r);
+
+      fd = rcl_f[0];
+   }
+   free (cl_r);
+   if (fd < 0)
+      return VK_ERROR_INITIALIZATION_FAILED;
+
+   wsi->fd = fd;
+
+   return VK_SUCCESS;
+}
+
+VkResult
+wsi_get_randr_output_display(VkPhysicalDevice physical_device,
+                             struct wsi_device *wsi_device,
+                             Display *dpy,
+                             RROutput output,
+                             VkDisplayKHR *display)
+{
+   xcb_connection_t *connection = XGetXCBConnection(dpy);
+   struct wsi_display_connector *connector =
+      wsi_display_get_output(wsi_device, connection, (xcb_randr_output_t) output);
+
+   if (connector)
+      *display = wsi_display_connector_to_handle(connector);
+   else
+      *display = NULL;
    return VK_SUCCESS;
 }
+
+#endif
diff --git a/src/vulkan/wsi/wsi_common_display.h b/src/vulkan/wsi/wsi_common_display.h
index f1e53484bac..eaa0ba727b0 100644
--- a/src/vulkan/wsi/wsi_common_display.h
+++ b/src/vulkan/wsi/wsi_common_display.h
@@ -87,4 +87,21 @@ wsi_release_display(VkPhysicalDevice            physical_device,
                     struct wsi_device           *wsi_device,
                     VkDisplayKHR                display);
 
+
+#if VK_USE_PLATFORM_XLIB_XRANDR_EXT
+VkResult
+wsi_acquire_xlib_display(VkPhysicalDevice       physical_device,
+                         struct wsi_device      *wsi_device,
+                         Display                *dpy,
+                         VkDisplayKHR           display);
+
+VkResult
+wsi_get_randr_output_display(VkPhysicalDevice   physical_device,
+                             struct wsi_device  *wsi_device,
+                             Display            *dpy,
+                             RROutput           output,
+                             VkDisplayKHR       *display);
+
+#endif /* VK_USE_PLATFORM_XLIB_XRANDR_EXT */
+
 #endif