Fix the creation of DRI2 buffers for pixmaps

Testing with gnome-shell revealed a problem. We need to migrate
pixmaps into UMP buffers in order to allow the GLESv2 based
compositing manager to actually access the content of redirected
windows, rendered by X11 applications into offscreen pixmaps.

Just to make sure that we don't add any unneeded overhead for 2D
(neither extra CPU cycles nor the increase for unrelated pixmaps
memory footprint), a hash table (currently uthash [1]) is used
for connecting DRI2-enabled pixmaps with UMP buffers. The lookups
are only performed on DRI2 buffer creation and pixmap destruction.

1. http://troydhanson.github.com/uthash/

Reported-by: Michal Suchanek <hramrach@gmail.com>
Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>

src/Makefile.am

@@ -30,6 +30,7 @@ sunxifb_drv_ladir = @moduledir@/drivers
 
 sunxifb_drv_la_SOURCES = \
          compat-api.h \
+         uthash.h \
          fbdev.c \
          fbdev_priv.h \
          sunxi_disp.c \

src/sunxi_mali_ump_dri2.c

@@ -127,17 +127,72 @@ WindowWalker(WindowPtr pWin, pointer value)
     return WT_WALKCHILDREN;
 }
 
+/* Migrate pixmap to UMP buffer */
+static UMPBufferInfoPtr
+MigratePixmapToUMP(PixmapPtr pPixmap)
+{
+    ScreenPtr pScreen = pPixmap->drawable.pScreen;
+    ScrnInfoPtr pScrn = xf86Screens[pScreen->myNum];
+    SunxiMaliDRI2 *self = SUNXI_MALI_UMP_DRI2(pScrn);
+    UMPBufferInfoPtr umpbuf;
+    size_t pitch = ((pPixmap->devKind + 7) / 8) * 8;
+    size_t size = pitch * pPixmap->drawable.height;
+
+    HASH_FIND_PTR(self->HashPixmapToUMP, &pPixmap, umpbuf);
+
+    if (umpbuf) {
+        DebugMsg("MigratePixmapToUMP %p, already exists = %p\n", pPixmap, umpbuf);
+        return umpbuf;
+    }
+
+    /* create the UMP buffer */
+    umpbuf = calloc(1, sizeof(UMPBufferInfoRec));
+    if (!umpbuf) {
+        ErrorF("MigratePixmapToUMP: calloc failed\n");
+        return NULL;
+    }
+    umpbuf->refcount = 1;
+    umpbuf->pPixmap = pPixmap;
+    umpbuf->handle = ump_ref_drv_allocate(size, UMP_REF_DRV_CONSTRAINT_PHYSICALLY_LINEAR);
+    if (umpbuf->handle == UMP_INVALID_MEMORY_HANDLE) {
+        ErrorF("MigratePixmapToUMP: ump_ref_drv_allocate failed\n");
+        free(umpbuf);
+        return NULL;
+    }
+    umpbuf->size = size;
+    umpbuf->addr = ump_mapped_pointer_get(umpbuf->handle);
+    umpbuf->depth = pPixmap->drawable.depth;
+    umpbuf->width = pPixmap->drawable.width;
+    umpbuf->height = pPixmap->drawable.height;
+
+    /* copy the pixel data to the new location */
+    if (pitch == pPixmap->devKind) {
+        memcpy(umpbuf->addr, pPixmap->devPrivate.ptr, size);
+    } else {
+        int y;
+        for (y = 0; y < umpbuf->height; y++) {
+            memcpy(umpbuf->addr + y * pitch, 
+                   pPixmap->devPrivate.ptr + y * pPixmap->devKind,
+                   pPixmap->devKind);
+        }
+    }
+
+    umpbuf->BackupDevKind = pPixmap->devKind;
+    umpbuf->BackupDevPrivatePtr = pPixmap->devPrivate.ptr;
+
+    pPixmap->devKind = pitch;
+    pPixmap->devPrivate.ptr = umpbuf->addr;
+
+    HASH_ADD_PTR(self->HashPixmapToUMP, pPixmap, umpbuf);
+
+    DebugMsg("MigratePixmapToUMP %p, new buf = %p\n", pPixmap, umpbuf);
+    return umpbuf;
+}
+
 static void UpdateOverlay(ScreenPtr pScreen);
 
-typedef struct
-{
-    ump_handle   handle;
-    size_t       size;
-    uint8_t *    addr;
-    int          depth;
-    size_t       width;
-    size_t       height;
-} MaliDRI2BufferPrivateRec, *MaliDRI2BufferPrivatePtr;
+typedef UMPBufferInfoRec MaliDRI2BufferPrivateRec;
+typedef UMPBufferInfoPtr MaliDRI2BufferPrivatePtr;
 
 static DRI2Buffer2Ptr MaliDRI2CreateBuffer(DrawablePtr  pDraw,
                                            unsigned int attachment,
@@ -145,21 +200,44 @@ static DRI2Buffer2Ptr MaliDRI2CreateBuffer(DrawablePtr  pDraw,
 {
     ScreenPtr                pScreen  = pDraw->pScreen;
     ScrnInfoPtr              pScrn    = xf86Screens[pScreen->myNum];
-    DRI2Buffer2Ptr           buffer   = calloc(1, sizeof *buffer);
-    MaliDRI2BufferPrivatePtr privates = calloc(1, sizeof *privates);
+    DRI2Buffer2Ptr           buffer;
+    MaliDRI2BufferPrivatePtr privates;
     ump_handle               handle;
     SunxiMaliDRI2 *private = SUNXI_MALI_UMP_DRI2(pScrn);
     sunxi_disp_t            *disp = SUNXI_DISP(pScrn);
     Bool                     can_use_overlay = TRUE;
 
-    if (!buffer || !privates) {
+    if (!(buffer = calloc(1, sizeof *buffer))) {
+        ErrorF("MaliDRI2CreateBuffer: calloc failed\n");
+        return NULL;
+    }
+
+    /* If it is a pixmap, just migrate this pixmap to UMP buffer */
+    if (pDraw->type == DRAWABLE_PIXMAP)
+    {
+        if (!(privates = MigratePixmapToUMP((PixmapPtr)pDraw))) {
+            ErrorF("MaliDRI2CreateBuffer: MigratePixmapToUMP failed\n");
             free(buffer);
-        free(privates);
-        ErrorF("MaliDRI2CreateBuffer: calloc failed\n\n");
             return NULL;
         }
+        privates->refcount++;
+        buffer->attachment    = attachment;
+        buffer->driverPrivate = privates;
+        buffer->format        = format;
+        buffer->flags         = 0;
+        buffer->cpp           = pDraw->bitsPerPixel / 8;
+        buffer->pitch         = ((PixmapPtr)pDraw)->devKind;
+        buffer->name = ump_secure_id_get(privates->handle);
+        return buffer;
+    }
 
-    /* The drawable must be a window */
+    if (!(privates = calloc(1, sizeof *privates))) {
+        ErrorF("MaliDRI2CreateBuffer: calloc failed\n");
+        free(buffer);
+        return NULL;
+    }
+
+    /* The drawable must be a window for using hardware overlays */
     if (pDraw->type != DRAWABLE_WINDOW)
         can_use_overlay = FALSE;
 
@@ -253,11 +331,17 @@ static void MaliDRI2DestroyBuffer(DrawablePtr pDraw, DRI2Buffer2Ptr buffer)
 
     if (buffer != NULL) {
         privates = (MaliDRI2BufferPrivatePtr)buffer->driverPrivate;
+        if (!privates->pPixmap) {
+            /* If pPixmap != 0, then these are freed in DestroyPixmap */
             if (privates->handle != UMP_INVALID_MEMORY_HANDLE) {
                 ump_mapped_pointer_release(privates->handle);
                 ump_reference_release(privates->handle);
             }
+        }
+        if (--privates->refcount <= 0) {
+            DebugMsg("free(privates)\n");
             free(privates);
+        }
         free(buffer);
     }
 }
@@ -479,6 +563,42 @@ GetImage(DrawablePtr pDrawable, int x, int y, int w, int h,
     }
 }
 
+static Bool
+DestroyPixmap(PixmapPtr pPixmap)
+{
+    ScreenPtr pScreen = pPixmap->drawable.pScreen;
+    ScrnInfoPtr pScrn = xf86Screens[pScreen->myNum];
+    SunxiMaliDRI2 *self = SUNXI_MALI_UMP_DRI2(pScrn);
+    Bool result;
+    UMPBufferInfoPtr umpbuf;
+    HASH_FIND_PTR(self->HashPixmapToUMP, &pPixmap, umpbuf);
+
+    if (umpbuf) {
+        DebugMsg("DestroyPixmap %p for migrated UMP pixmap (UMP buffer=%p)\n", pPixmap, umpbuf);
+
+        pPixmap->devKind = umpbuf->BackupDevKind;
+        pPixmap->devPrivate.ptr = umpbuf->BackupDevPrivatePtr;
+
+        ump_mapped_pointer_release(umpbuf->handle);
+        ump_reference_release(umpbuf->handle);
+
+        HASH_DEL(self->HashPixmapToUMP, umpbuf);
+        DebugMsg("umpbuf->refcount=%d\n", umpbuf->refcount);
+        if (--umpbuf->refcount <= 0) {
+            DebugMsg("free(umpbuf)\n");
+            free(umpbuf);
+        }
+    }
+
+    pScreen->DestroyPixmap = self->DestroyPixmap;
+    result = (*pScreen->DestroyPixmap) (pPixmap);
+    self->DestroyPixmap = pScreen->DestroyPixmap;
+    pScreen->DestroyPixmap = DestroyPixmap;
+
+
+    return result;
+}
+
 SunxiMaliDRI2 *SunxiMaliDRI2_Init(ScreenPtr pScreen, Bool bUseOverlay)
 {
     int drm_fd;
@@ -554,6 +674,9 @@ SunxiMaliDRI2 *SunxiMaliDRI2_Init(ScreenPtr pScreen, Bool bUseOverlay)
         /* Wrap the current GetImage function */
         private->GetImage = pScreen->GetImage;
         pScreen->GetImage = GetImage;
+        /* Wrap the current DestroyPixmap function */
+        private->DestroyPixmap = pScreen->DestroyPixmap;
+        pScreen->DestroyPixmap = DestroyPixmap;
 
         private->ump_fb_secure_id = ump_id_fb;
         private->drm_fd = drm_fd;
@@ -570,6 +693,7 @@ void SunxiMaliDRI2_Close(ScreenPtr pScreen)
     pScreen->DestroyWindow    = private->DestroyWindow;
     pScreen->PostValidateTree = private->PostValidateTree;
     pScreen->GetImage         = private->GetImage;
+    pScreen->DestroyPixmap    = private->DestroyPixmap;
 
     drmClose(private->drm_fd);
     DRI2CloseScreen(pScreen);

src/sunxi_mali_ump_dri2.h

@@ -27,6 +27,26 @@
 #include <ump/ump.h>
 #include <ump/ump_ref_drv.h>
 
+#include "uthash.h"
+
+/* Data structure with the information about an UMP buffer */
+typedef struct
+{
+    /* The migrated pixmap (may be NULL if it is a window) */
+    PixmapPtr               pPixmap;
+    int                     BackupDevKind;
+    void                   *BackupDevPrivatePtr;
+    int                     refcount;
+    UT_hash_handle          hh;
+
+    ump_handle              handle;
+    size_t                  size;
+    uint8_t                *addr;
+    int                     depth;
+    size_t                  width;
+    size_t                  height;
+} UMPBufferInfoRec, *UMPBufferInfoPtr;
+
 typedef struct {
     int                     overlay_x;
     int                     overlay_y;
@@ -40,8 +60,11 @@ typedef struct {
     DestroyWindowProcPtr    DestroyWindow;
     PostValidateTreeProcPtr PostValidateTree;
     GetImageProcPtr         GetImage;
+    DestroyPixmapProcPtr    DestroyPixmap;
     ump_secure_id           ump_fb_secure_id;
 
+    UMPBufferInfoPtr        HashPixmapToUMP;
+
     int                     drm_fd;
 } SunxiMaliDRI2;