drm/i915: remove early fb allocation dependency on CONFIG_FB v2

By stuffing the fb allocation into the crtc, we get mode set lifetime
refcounting for free, but have to handle the initial pin & fence
slightly differently.  It also means we can move the shared fb handling
into the core rather than leaving it out in the fbdev code.

v2: null out crtc->fb on error (Daniel)
    take fbdev fb ref and remove unused error path (Daniel)

Requested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

3 files changed, 105 insertions, 79 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index d3c29116711f..8710496bab4c 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2068,7 +2068,7 @@ int intel_format_to_fourcc(int format)
         }
 }
 
-static void intel_alloc_plane_obj(struct intel_crtc *crtc,
+static bool intel_alloc_plane_obj(struct intel_crtc *crtc,
                                   struct intel_plane_config *plane_config)
 {
         struct drm_device *dev = crtc->base.dev;
@@ -2076,38 +2076,76 @@ static void intel_alloc_plane_obj(struct intel_crtc *crtc,
         struct drm_mode_fb_cmd2 mode_cmd = { 0 };
         u32 base = plane_config->base;
 
-        if (!plane_config->fb)
-                return;
-
         obj = i915_gem_object_create_stolen_for_preallocated(dev, base, base,
                                                              plane_config->size);
         if (!obj)
-                return;
+                return false;
 
         if (plane_config->tiled) {
                 obj->tiling_mode = I915_TILING_X;
-                obj->stride = plane_config->fb->base.pitches[0];
+                obj->stride = crtc->base.fb->pitches[0];
         }
 
-        mode_cmd.pixel_format = plane_config->fb->base.pixel_format;
-        mode_cmd.width = plane_config->fb->base.width;
-        mode_cmd.height = plane_config->fb->base.height;
-        mode_cmd.pitches[0] = plane_config->fb->base.pitches[0];
+        mode_cmd.pixel_format = crtc->base.fb->pixel_format;
+        mode_cmd.width = crtc->base.fb->width;
+        mode_cmd.height = crtc->base.fb->height;
+        mode_cmd.pitches[0] = crtc->base.fb->pitches[0];
 
         mutex_lock(&dev->struct_mutex);
 
-        if (intel_framebuffer_init(dev, plane_config->fb, &mode_cmd, obj)) {
+        if (intel_framebuffer_init(dev, to_intel_framebuffer(crtc->base.fb),
+                                   &mode_cmd, obj)) {
                 DRM_DEBUG_KMS("intel fb init failed\n");
                 goto out_unref_obj;
         }
 
         mutex_unlock(&dev->struct_mutex);
-        DRM_DEBUG_KMS("plane fb obj %p\n", plane_config->fb->obj);
-        return;
+
+        DRM_DEBUG_KMS("plane fb obj %p\n", obj);
+        return true;
 
 out_unref_obj:
         drm_gem_object_unreference(&obj->base);
         mutex_unlock(&dev->struct_mutex);
+        return false;
+}
+
+static void intel_find_plane_obj(struct intel_crtc *intel_crtc,
+                                 struct intel_plane_config *plane_config)
+{
+        struct drm_device *dev = intel_crtc->base.dev;
+        struct drm_crtc *c;
+        struct intel_crtc *i;
+        struct intel_framebuffer *fb;
+
+        if (!intel_crtc->base.fb)
+                return;
+
+        if (intel_alloc_plane_obj(intel_crtc, plane_config))
+                return;
+
+        kfree(intel_crtc->base.fb);
+
+        /*
+         * Failed to alloc the obj, check to see if we should share
+         * an fb with another CRTC instead
+         */
+        list_for_each_entry(c, &dev->mode_config.crtc_list, head) {
+                i = to_intel_crtc(c);
+
+                if (c == &intel_crtc->base)
+                        continue;
+
+                if (!i->active || !c->fb)
+                        continue;
+
+                fb = to_intel_framebuffer(c->fb);
+                if (i915_gem_obj_ggtt_offset(fb->obj) == plane_config->base) {
+                        drm_framebuffer_reference(c->fb);
+                        intel_crtc->base.fb = c->fb;
+                        break;
+                }
+        }
 }
 
 static int i9xx_update_plane(struct drm_crtc *crtc, struct drm_framebuffer *fb,
@@ -5678,8 +5716,8 @@ static void i9xx_get_plane_config(struct intel_crtc *crtc,
         int fourcc, pixel_format;
         int aligned_height;
 
-        plane_config->fb = kzalloc(sizeof(*plane_config->fb), GFP_KERNEL);
-        if (!plane_config->fb) {
+        crtc->base.fb = kzalloc(sizeof(struct intel_framebuffer), GFP_KERNEL);
+        if (!crtc->base.fb) {
                 DRM_DEBUG_KMS("failed to alloc fb\n");
                 return;
         }
@@ -5692,8 +5730,8 @@ static void i9xx_get_plane_config(struct intel_crtc *crtc,
 
         pixel_format = val & DISPPLANE_PIXFORMAT_MASK;
         fourcc = intel_format_to_fourcc(pixel_format);
-        plane_config->fb->base.pixel_format = fourcc;
-        plane_config->fb->base.bits_per_pixel =
+        crtc->base.fb->pixel_format = fourcc;
+        crtc->base.fb->bits_per_pixel =
                 drm_format_plane_cpp(fourcc, 0) * 8;
 
         if (INTEL_INFO(dev)->gen >= 4) {
@@ -5708,23 +5746,23 @@ static void i9xx_get_plane_config(struct intel_crtc *crtc,
         plane_config->base = base;
 
         val = I915_READ(PIPESRC(pipe));
-        plane_config->fb->base.width = ((val >> 16) & 0xfff) + 1;
-        plane_config->fb->base.height = ((val >> 0) & 0xfff) + 1;
+        crtc->base.fb->width = ((val >> 16) & 0xfff) + 1;
+        crtc->base.fb->height = ((val >> 0) & 0xfff) + 1;
 
         val = I915_READ(DSPSTRIDE(pipe));
-        plane_config->fb->base.pitches[0] = val & 0xffffff80;
+        crtc->base.fb->pitches[0] = val & 0xffffff80;
 
-        aligned_height = intel_align_height(dev, plane_config->fb->base.height,
+        aligned_height = intel_align_height(dev, crtc->base.fb->height,
                                             plane_config->tiled);
 
-        plane_config->size = ALIGN(plane_config->fb->base.pitches[0] *
+        plane_config->size = ALIGN(crtc->base.fb->pitches[0] *
                                    aligned_height, PAGE_SIZE);
 
         DRM_DEBUG_KMS("pipe/plane %d/%d with fb: size=%dx%d@%d, offset=%x, pitch %d, size 0x%x\n",
-                      pipe, plane, plane_config->fb->base.width,
-                      plane_config->fb->base.height,
-                      plane_config->fb->base.bits_per_pixel, base,
-                      plane_config->fb->base.pitches[0],
+                      pipe, plane, crtc->base.fb->width,
+                      crtc->base.fb->height,
+                      crtc->base.fb->bits_per_pixel, base,
+                      crtc->base.fb->pitches[0],
                       plane_config->size);
 
 }
@@ -6686,8 +6724,8 @@ static void ironlake_get_plane_config(struct intel_crtc *crtc,
         int fourcc, pixel_format;
         int aligned_height;
 
-        plane_config->fb = kzalloc(sizeof(*plane_config->fb), GFP_KERNEL);
-        if (!plane_config->fb) {
+        crtc->base.fb = kzalloc(sizeof(struct intel_framebuffer), GFP_KERNEL);
+        if (!crtc->base.fb) {
                 DRM_DEBUG_KMS("failed to alloc fb\n");
                 return;
         }
@@ -6700,8 +6738,8 @@ static void ironlake_get_plane_config(struct intel_crtc *crtc,
 
         pixel_format = val & DISPPLANE_PIXFORMAT_MASK;
         fourcc = intel_format_to_fourcc(pixel_format);
-        plane_config->fb->base.pixel_format = fourcc;
-        plane_config->fb->base.bits_per_pixel =
+        crtc->base.fb->pixel_format = fourcc;
+        crtc->base.fb->bits_per_pixel =
                 drm_format_plane_cpp(fourcc, 0) * 8;
 
         base = I915_READ(DSPSURF(plane)) & 0xfffff000;
@@ -6716,23 +6754,23 @@ static void ironlake_get_plane_config(struct intel_crtc *crtc,
         plane_config->base = base;
 
         val = I915_READ(PIPESRC(pipe));
-        plane_config->fb->base.width = ((val >> 16) & 0xfff) + 1;
-        plane_config->fb->base.height = ((val >> 0) & 0xfff) + 1;
+        crtc->base.fb->width = ((val >> 16) & 0xfff) + 1;
+        crtc->base.fb->height = ((val >> 0) & 0xfff) + 1;
 
         val = I915_READ(DSPSTRIDE(pipe));
-        plane_config->fb->base.pitches[0] = val & 0xffffff80;
+        crtc->base.fb->pitches[0] = val & 0xffffff80;
 
-        aligned_height = intel_align_height(dev, plane_config->fb->base.height,
+        aligned_height = intel_align_height(dev, crtc->base.fb->height,
                                             plane_config->tiled);
 
-        plane_config->size = ALIGN(plane_config->fb->base.pitches[0] *
+        plane_config->size = ALIGN(crtc->base.fb->pitches[0] *
                                    aligned_height, PAGE_SIZE);
 
         DRM_DEBUG_KMS("pipe/plane %d/%d with fb: size=%dx%d@%d, offset=%x, pitch %d, size 0x%x\n",
-                      pipe, plane, plane_config->fb->base.width,
-                      plane_config->fb->base.height,
-                      plane_config->fb->base.bits_per_pixel, base,
-                      plane_config->fb->base.pitches[0],
+                      pipe, plane, crtc->base.fb->width,
+                      crtc->base.fb->height,
+                      crtc->base.fb->bits_per_pixel, base,
+                      crtc->base.fb->pitches[0],
                       plane_config->size);
 }
 
@@ -11290,10 +11328,7 @@ void intel_modeset_init(struct drm_device *dev)
                 if (!crtc->active)
                         continue;
 
-#if IS_ENABLED(CONFIG_FB)
                 /*
-                 * We don't have a good way of freeing the buffer w/o the FB
-                 * layer owning it...
                  * Note that reserving the BIOS fb up front prevents us
                  * from stuffing other stolen allocations like the ring
                  * on top.  This prevents some ugliness at boot time, and
@@ -11307,9 +11342,8 @@ void intel_modeset_init(struct drm_device *dev)
                          * If the fb is shared between multiple heads, we'll
                          * just get the first one.
                          */
-                        intel_alloc_plane_obj(crtc, &crtc->plane_config);
+                        intel_find_plane_obj(crtc, &crtc->plane_config);
                 }
-#endif
         }
 }
 
@@ -11680,9 +11714,32 @@ void intel_modeset_setup_hw_state(struct drm_device *dev,
 
 void intel_modeset_gem_init(struct drm_device *dev)
 {
+        struct drm_crtc *c;
+        struct intel_framebuffer *fb;
+
         intel_modeset_init_hw(dev);
 
         intel_setup_overlay(dev);
+
+        /*
+         * Make sure any fbs we allocated at startup are properly
+         * pinned & fenced.  When we do the allocation it's too early
+         * for this.
+         */
+        mutex_lock(&dev->struct_mutex);
+        list_for_each_entry(c, &dev->mode_config.crtc_list, head) {
+                if (!c->fb)
+                        continue;
+
+                fb = to_intel_framebuffer(c->fb);
+                if (intel_pin_and_fence_fb_obj(dev, fb->obj, NULL)) {
+                        DRM_ERROR("failed to pin boot fb on pipe %d\n",
+                                  to_intel_crtc(c)->pipe);
+                        drm_framebuffer_unreference(c->fb);
+                        c->fb = NULL;
+                }
+        }
+        mutex_unlock(&dev->struct_mutex);
 }
 
 void intel_connector_unregister(struct intel_connector *intel_connector)
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 75baa64a357d..5360d1628263 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -220,7 +220,6 @@ typedef struct dpll {
 } intel_clock_t;
 
 struct intel_plane_config {
-        struct intel_framebuffer *fb; /* ends up managed by intel_fbdev.c */
         bool tiled;
         int size;
         u32 base;
diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
index 32a05edc517c..d6d78c86c232 100644
--- a/drivers/gpu/drm/i915/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/intel_fbdev.c
@@ -481,7 +481,7 @@ static bool intel_fbdev_init_bios(struct drm_device *dev,
         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
                 intel_crtc = to_intel_crtc(crtc);
 
-                if (!intel_crtc->active || !intel_crtc->plane_config.fb) {
+                if (!intel_crtc->active || !crtc->fb) {
                         DRM_DEBUG_KMS("pipe %c not active or no fb, skipping\n",
                                       pipe_name(intel_crtc->pipe));
                         continue;
@@ -491,7 +491,7 @@ static bool intel_fbdev_init_bios(struct drm_device *dev,
                         DRM_DEBUG_KMS("found possible fb from plane %c\n",
                                       pipe_name(intel_crtc->pipe));
                         plane_config = &intel_crtc->plane_config;
-                        fb = plane_config->fb;
+                        fb = to_intel_framebuffer(crtc->fb);
                         max_size = plane_config->size;
                 }
         }
@@ -543,43 +543,15 @@ static bool intel_fbdev_init_bios(struct drm_device *dev,
                               max_size, cur_size);
         }
 
-        /* Free unused fbs */
-        list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
-                struct intel_framebuffer *cur_fb;
-
-                intel_crtc = to_intel_crtc(crtc);
-                cur_fb = intel_crtc->plane_config.fb;
-
-                if (cur_fb && cur_fb != fb)
-                        drm_framebuffer_unreference(&cur_fb->base);
-        }
-
         if (!fb) {
                 DRM_DEBUG_KMS("BIOS fb not suitable for all pipes, not using\n");
                 goto out;
         }
 
-        ifbdev->preferred_bpp = plane_config->fb->base.bits_per_pixel;
+        ifbdev->preferred_bpp = fb->base.bits_per_pixel;
         ifbdev->fb = fb;
 
-        /* Assuming a single fb across all pipes here */
-        list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
-                intel_crtc = to_intel_crtc(crtc);
-
-                if (!intel_crtc->active)
-                        continue;
-
-                /*
-                 * This should only fail on the first one so we don't need
-                 * to cleanup any secondary crtc->fbs
-                 */
-                if (intel_pin_and_fence_fb_obj(dev, fb->obj, NULL))
-                        goto out_unref_obj;
-
-                crtc->fb = &fb->base;
-                drm_gem_object_reference(&fb->obj->base);
-                drm_framebuffer_reference(&fb->base);
-        }
+        drm_framebuffer_reference(&ifbdev->fb->base);
 
         /* Final pass to check if any active pipes don't have fbs */
         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
@@ -597,8 +569,6 @@ static bool intel_fbdev_init_bios(struct drm_device *dev,
         DRM_DEBUG_KMS("using BIOS fb for initial console\n");
         return true;
 
-out_unref_obj:
-        drm_framebuffer_unreference(&fb->base);
 out:
 
         return false;