[PATCH 4/4] modesetting: Add support for using shadow buffers

[Jason Ekstrand]

This replaces the stubs for shadow buffer creation/allocation with actual
functions and adds a shadow_destroy function.  With this, we actually get
shadow buffers and RandR now works properly.  Most of this is copied from
the xf86-video-intel driver and modified for modesetting.

Signed-off-by: Jason Ekstrand <jason.ekstrand at intel.com>
---
 hw/xfree86/drivers/modesetting/drmmode_display.c | 116 ++++++++++++++++++++++-
 1 file changed, 114 insertions(+), 2 deletions(-)

diff --git a/hw/xfree86/drivers/modesetting/drmmode_display.c b/hw/xfree86/drivers/modesetting/drmmode_display.c
index 5648d7b..8ac5c77 100644
--- a/hw/xfree86/drivers/modesetting/drmmode_display.c
+++ b/hw/xfree86/drivers/modesetting/drmmode_display.c
@@ -510,13 +510,124 @@ drmmode_set_scanout_pixmap(xf86CrtcPtr crtc, PixmapPtr ppix)
 static void *
 drmmode_shadow_allocate(xf86CrtcPtr crtc, int width, int height)
 {
-    return NULL;
+    drmmode_crtc_private_ptr drmmode_crtc = crtc->driver_private;
+    drmmode_ptr drmmode = drmmode_crtc->drmmode;
+    int ret;
+
+    if (!drmmode_create_bo(drmmode, &drmmode->shadow_bo,
+                           width, height, drmmode->cpp)) {
+        xf86DrvMsg(crtc->scrn->scrnIndex, X_ERROR,
+               "Couldn't allocate shadow memory for rotated CRTC\n");
+        return NULL;
+    }
+
+    ret = drmModeAddFB(drmmode->fd, width, height, crtc->scrn->depth,
+                       crtc->scrn->bitsPerPixel,
+                       drmmode_bo_get_pitch(&drmmode->shadow_bo),
+                       drmmode_bo_get_handle(&drmmode->shadow_bo),
+                       &drmmode_crtc->rotate_fb_id);
+
+    if (ret) {
+        ErrorF("failed to add rotate fb\n");
+        drmmode_bo_destroy(drmmode, &drmmode->shadow_bo);
+        return NULL;
+    }
+
+#ifdef GLAMOR_HAS_GBM
+    if (drmmode->gbm)
+        return drmmode->shadow_bo.gbm;
+#endif
+    return drmmode->shadow_bo.dumb;
+}
+
+static PixmapPtr
+drmmode_create_pixmap_header(ScreenPtr pScreen, int width, int height,
+                             int depth, int bitsPerPixel, int devKind,
+                             void *pPixData)
+{
+    PixmapPtr pixmap;
+
+    /* width and height of 0 means don't allocate any pixmap data */
+    pixmap = (*pScreen->CreatePixmap)(pScreen, 0, 0, depth, 0);
+
+    if (pixmap) {
+        if ((*pScreen->ModifyPixmapHeader)(pixmap, width, height, depth,
+                                           bitsPerPixel, devKind, pPixData))
+            return pixmap;
+        (*pScreen->DestroyPixmap)(pixmap);
+    }
+    return NullPixmap;
 }
 
+static Bool
+drmmode_set_pixmap_bo(drmmode_ptr drmmode, PixmapPtr pixmap, drmmode_bo *bo);
+
 static PixmapPtr
 drmmode_shadow_create(xf86CrtcPtr crtc, void *data, int width, int height)
 {
-    return NULL;
+    ScrnInfoPtr scrn = crtc->scrn;
+    drmmode_crtc_private_ptr drmmode_crtc = crtc->driver_private;
+    drmmode_ptr drmmode = drmmode_crtc->drmmode;
+    uint32_t shadow_pitch;
+    PixmapPtr shadow_pixmap;
+
+    if (!data) {
+        data = drmmode_shadow_allocate(crtc, width, height);
+        if (!data) {
+            xf86DrvMsg(scrn->scrnIndex, X_ERROR,
+                       "Couldn't allocate shadow pixmap for rotated CRTC\n");
+            return NULL;
+        }
+    }
+
+    if (drmmode->shadow_bo.gbm == NULL && drmmode->shadow_bo.dumb == NULL) {
+        xf86DrvMsg(scrn->scrnIndex, X_ERROR,
+                   "Couldn't allocate shadow pixmap for rotated CRTC\n");
+        return NULL;
+    }
+
+    shadow_pitch = drmmode_bo_get_pitch(&drmmode->shadow_bo),
+
+    shadow_pixmap = drmmode_create_pixmap_header(scrn->pScreen,
+                                                 width, height,
+                                                 scrn->depth,
+                                                 scrn->bitsPerPixel,
+                                                 shadow_pitch,
+                                                 NULL);
+
+    if (shadow_pixmap == NULL) {
+        xf86DrvMsg(scrn->scrnIndex, X_ERROR,
+                   "Couldn't allocate shadow pixmap for rotated CRTC\n");
+        return NULL;
+    }
+
+    drmmode_set_pixmap_bo(drmmode, shadow_pixmap, &drmmode->shadow_bo);
+
+    drmmode->shadow_enable = TRUE;
+
+    return shadow_pixmap;
+}
+
+static void
+drmmode_shadow_destroy(xf86CrtcPtr crtc, PixmapPtr shadow_pixmap, void *data)
+{
+    drmmode_crtc_private_ptr drmmode_crtc = crtc->driver_private;
+    drmmode_ptr drmmode = drmmode_crtc->drmmode;
+
+    if (shadow_pixmap) {
+        drmmode_set_pixmap_bo(drmmode, shadow_pixmap, NULL);
+        shadow_pixmap->drawable.pScreen->DestroyPixmap(shadow_pixmap);
+    }
+
+    if (data) {
+        drmModeRmFB(drmmode->fd, drmmode_crtc->rotate_fb_id);
+        drmmode_crtc->rotate_fb_id = 0;
+
+        drmmode_bo_destroy(drmmode, &drmmode->shadow_bo);
+        memset(&drmmode->shadow_bo, 0, sizeof drmmode->shadow_bo);
+    }
+
+    drmmode->shadow_enable = FALSE;
 }
 
 static const xf86CrtcFuncsRec drmmode_crtc_funcs = {
@@ -533,6 +644,7 @@ static const xf86CrtcFuncsRec drmmode_crtc_funcs = {
     .set_scanout_pixmap = drmmode_set_scanout_pixmap,
     .shadow_allocate = drmmode_shadow_allocate,
     .shadow_create = drmmode_shadow_create,
+    .shadow_destroy = drmmode_shadow_destroy,
 };
 
 static uint32_t
-- 
2.2.0