gallium: add renderonly library

This a very lightweight library to add basic support for renderonly
GPUs. A kms gallium driver must specify how a renderonly_scanout
objects gets created. Also it must provide file handles to the used
kms device and the used gpu device.

This could look like:
struct renderonly ro = {
   .create_for_resource = renderonly_create_gpu_import_for_resource,
   .kms_fd = fd,
   .gpu_fd = open("/dev/dri/renderD128", O_RDWR | O_CLOEXEC)
};

The renderonly_scanout object exits for two reasons:
 - Do any special treatment for a scanout resource like importing the
   GPU resource into the scanout hw.
 - Make it easier for a gallium driver to detect if anything special
   needs to be done in flush_resource(..) like a resolve to linear.

A GPU gallium driver which gets used as renderonly GPU needs to be
aware of the renderonly library.

This library will likely break android support and hopefully will get
replaced with a better solution based on gbm2.

Changes from V1 -> V2:
 - reworked the lifecycle of renderonly object (suggested by Nicolai Hähnle)
 - killed the midlayer (suggested by Thierry Reding)
 - made the API more explicit regarding gpu and kms fd's
 - added some docs

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Acked-by: Emil Velikov <emil.velikov@collabora.com>
Tested-by: Alexandre Courbot <acourbot@nvidia.com>

src/gallium/Automake.inc

@@ -50,6 +50,11 @@ GALLIUM_COMMON_LIB_DEPS = \
 	$(PTHREAD_LIBS) \
 	$(DLOPEN_LIBS)
 
+if HAVE_LIBDRM
+GALLIUM_COMMON_LIB_DEPS += \
+	$(LIBDRM_LIBS)
+endif
+
 GALLIUM_WINSYS_CFLAGS = \
 	-I$(top_srcdir)/src \
 	-I$(top_srcdir)/include \

src/gallium/auxiliary/Makefile.am

@@ -20,6 +20,16 @@ libgallium_la_SOURCES = \
 	$(NIR_SOURCES) \
 	$(GENERATED_SOURCES)
 
+if HAVE_LIBDRM
+
+AM_CFLAGS += \
+	$(LIBDRM_CFLAGS)
+
+libgallium_la_SOURCES += \
+	$(RENDERONLY_SOURCES)
+
+endif
+
 if HAVE_GALLIUM_LLVM
 
 AM_CFLAGS += \

src/gallium/auxiliary/Makefile.sources

@@ -435,3 +435,7 @@ GALLIVM_SOURCES := \
 	draw/draw_llvm_sample.c \
 	draw/draw_pt_fetch_shade_pipeline_llvm.c \
 	draw/draw_vs_llvm.c
+
+RENDERONLY_SOURCES := \
+	renderonly/renderonly.c \
+	renderonly/renderonly.h

src/gallium/auxiliary/renderonly/renderonly.c

@@ -0,0 +1,175 @@
+/*
+ * Copyright (C) 2016 Christian Gmeiner <christian.gmeiner@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Authors:
+ *    Christian Gmeiner <christian.gmeiner@gmail.com>
+ */
+
+#include "renderonly/renderonly.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <sys/ioctl.h>
+#include <xf86drm.h>
+
+#include "state_tracker/drm_driver.h"
+#include "pipe/p_screen.h"
+#include "util/u_memory.h"
+
+struct renderonly *
+renderonly_dup(const struct renderonly *ro)
+{
+   struct renderonly *copy;
+
+   copy = CALLOC_STRUCT(renderonly);
+   if (!copy)
+      return NULL;
+
+   memcpy(copy, ro, sizeof(*ro));
+
+   return copy;
+}
+
+struct renderonly_scanout *
+renderonly_scanout_for_prime(struct pipe_resource *rsc, struct renderonly *ro)
+{
+   struct renderonly_scanout *scanout;
+
+   scanout = CALLOC_STRUCT(renderonly_scanout);
+   if (!scanout)
+      return NULL;
+
+   scanout->prime = rsc;
+
+   return scanout;
+}
+
+void
+renderonly_scanout_destroy(struct renderonly_scanout *scanout)
+{
+   FREE(scanout);
+}
+
+struct renderonly_scanout *
+renderonly_create_kms_dumb_buffer_for_resource(struct pipe_resource *rsc,
+                                               struct renderonly *ro)
+{
+   struct pipe_screen *screen = rsc->screen;
+   struct renderonly_scanout *scanout;
+   struct winsys_handle handle;
+   int prime_fd, err;
+   struct drm_mode_create_dumb create_dumb = {
+      .width = rsc->width0,
+      .height = rsc->height0,
+      .bpp = 32,
+   };
+   struct drm_mode_destroy_dumb destroy_dumb = { };
+
+   scanout = CALLOC_STRUCT(renderonly_scanout);
+   if (!scanout)
+      return NULL;
+
+   /* create dumb buffer at scanout GPU */
+   err = ioctl(ro->kms_fd, DRM_IOCTL_MODE_CREATE_DUMB, &create_dumb);
+   if (err < 0) {
+      fprintf(stderr, "DRM_IOCTL_MODE_CREATE_DUMB failed: %s\n",
+            strerror(errno));
+      goto free_scanout;
+   }
+
+   scanout->handle = create_dumb.handle;
+   scanout->stride = create_dumb.pitch;
+
+   /* export dumb buffer */
+   err = drmPrimeHandleToFD(ro->kms_fd, create_dumb.handle, O_CLOEXEC,
+         &prime_fd);
+   if (err < 0) {
+      fprintf(stderr, "failed to export dumb buffer: %s\n", strerror(errno));
+      goto free_dumb;
+   }
+
+   /* import dumb buffer */
+   handle.type = DRM_API_HANDLE_TYPE_FD;
+   handle.handle = prime_fd;
+   handle.stride = create_dumb.pitch;
+
+   scanout->prime = screen->resource_from_handle(screen, rsc,
+         &handle, PIPE_HANDLE_USAGE_READ_WRITE);
+
+   if (!scanout->prime) {
+      fprintf(stderr, "failed to create resource_from_handle: %s\n", strerror(errno));
+      goto free_dumb;
+   }
+
+   return scanout;
+
+free_dumb:
+   destroy_dumb.handle = scanout->handle;
+   ioctl(ro->kms_fd, DRM_IOCTL_MODE_DESTROY_DUMB, &destroy_dumb);
+
+free_scanout:
+   FREE(scanout);
+
+   return NULL;
+}
+
+struct renderonly_scanout *
+renderonly_create_gpu_import_for_resource(struct pipe_resource *rsc,
+                                          struct renderonly *ro)
+{
+   struct pipe_screen *screen = rsc->screen;
+   struct renderonly_scanout *scanout;
+   boolean status;
+   int fd, err;
+   struct winsys_handle handle = {
+      .type = DRM_API_HANDLE_TYPE_FD
+   };
+
+   scanout = CALLOC_STRUCT(renderonly_scanout);
+   if (!scanout)
+      return NULL;
+
+   status = screen->resource_get_handle(screen, NULL, rsc, &handle,
+         PIPE_HANDLE_USAGE_READ_WRITE);
+   if (!status)
+      goto free_scanout;
+
+   scanout->stride = handle.stride;
+   fd = handle.handle;
+
+   err = drmPrimeFDToHandle(ro->kms_fd, fd, &scanout->handle);
+   close(fd);
+
+   if (err < 0) {
+      fprintf(stderr, "drmPrimeFDToHandle() failed: %s\n", strerror(errno));
+      goto free_scanout;
+   }
+
+   return scanout;
+
+free_scanout:
+   FREE(scanout);
+
+   return NULL;
+}
+

src/gallium/auxiliary/renderonly/renderonly.h

@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2016 Christian Gmeiner <christian.gmeiner@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Authors:
+ *    Christian Gmeiner <christian.gmeiner@gmail.com>
+ */
+
+#ifndef RENDERONLY_H
+#define RENDERONLY_H
+
+#include <stdint.h>
+#include "state_tracker/drm_driver.h"
+#include "pipe/p_state.h"
+
+struct renderonly_scanout {
+   uint32_t handle;
+   uint32_t stride;
+
+   struct pipe_resource *prime;
+};
+
+struct renderonly {
+   /**
+    * Create a renderonly_scanout object for scanout resource.
+    *
+    * This function creates a renderonly_scanout object based on the provided
+    * resource. The library is designed that the driver specific pipe_resource
+    * struct holds a pointer to a renderonly_scanout struct.
+    *
+    * struct driver_resource {
+    *    struct pipe_resource base;
+    *    struct renderonly_scanout *scanout;
+    *   ...
+    * };
+    *
+    * The renderonly_scanout object exits for two reasons:
+    * - Do any special treatment for a scanout resource like importing the GPU
+    *   resource into the scanout hw.
+    * - Make it easier for a gallium driver to detect if anything special needs
+    *   to be done in flush_resource(..) like a resolve to linear.
+    */
+   struct renderonly_scanout *(*create_for_resource)(struct pipe_resource *rsc,
+                                                     struct renderonly *ro);
+   int kms_fd;
+   int gpu_fd;
+};
+
+struct renderonly *
+renderonly_dup(const struct renderonly *ro);
+
+static inline struct renderonly_scanout *
+renderonly_scanout_for_resource(struct pipe_resource *rsc, struct renderonly *ro)
+{
+   return ro->create_for_resource(rsc, ro);
+}
+
+struct renderonly_scanout *
+renderonly_scanout_for_prime(struct pipe_resource *rsc, struct renderonly *ro);
+
+void
+renderonly_scanout_destroy(struct renderonly_scanout *scanout);
+
+static inline boolean
+renderonly_get_handle(struct renderonly_scanout *scanout,
+      struct winsys_handle *handle)
+{
+   if (!scanout)
+      return FALSE;
+
+   handle->handle = scanout->handle;
+   handle->stride = scanout->stride;
+
+   return TRUE;
+}
+
+/**
+ * Create a dumb buffer object for a resource at scanout hw.
+ */
+struct renderonly_scanout *
+renderonly_create_kms_dumb_buffer_for_resource(struct pipe_resource *rsc,
+                                               struct renderonly *ro);
+
+/**
+ * Import GPU resource into scanout hw.
+ */
+struct renderonly_scanout *
+renderonly_create_gpu_import_for_resource(struct pipe_resource *rsc,
+                                          struct renderonly *ro);
+
+#endif /* RENDERONLY_H_ */