radeon: avoid using hw pixmaps when we have little VRAM.

This patch returns NULL for pixmap creation when we are using
mixed pixmaps and the pixmap has a size.

The size check is necessary for the front buffer.

We add a flag to force pixmap creation for certain pixmaps
that need to be hw, like the DRI2 and Xv ones.

Idea from Michel and workarounds from Ben Skeggs.

v2: add Option "EXALowVRAM" to allow configuring this, value in MBs.

Signed-off-by: Dave Airlie <airlied@redhat.com>

6 files changed, 50 insertions, 1 deletions

diff --git a/man/radeon.man b/man/radeon.man
index 47fa9f5e..5f6d9fb0 100644
--- a/man/radeon.man
+++ b/man/radeon.man
@@ -606,6 +606,15 @@ The default is
 This option enables modesetting on R/RV4xx chips using atombios.
 The default is
 .B off.
+.TP 
+.BI "Option \*qEXALowVRAM\*q \*q" integer \*q
+(KMS Only) Under kernel modesetting to avoid thrashing pixmaps in/out
+of VRAM on low memory cards, we set a threshhold for the amount of VRAM
+a GPU should have before we start using VRAM to accelerate pixmaps that
+aren't required to be used by the GPU. Value is in MB. This shouldn't
+really be changed apart from testing.
+The default is
+.B 32.
 
 .SH TEXTURED VIDEO ATTRIBUTES
 The driver supports the following X11 Xv attributes for Textured Video.
diff --git a/src/radeon.h b/src/radeon.h
index 1e479f4e..0dbaa52a 100644
--- a/src/radeon.h
+++ b/src/radeon.h
@@ -173,6 +173,7 @@ typedef enum {
     OPTION_PCIAPER_SIZE,
 #ifdef USE_EXA
     OPTION_ACCEL_DFS,
+    OPTION_EXA_LOW_VRAM,
 #endif
 #endif
     OPTION_IGNORE_EDID,
@@ -894,6 +895,7 @@ typedef struct {
     Bool              accelOn;
     Bool              useEXA;
 #ifdef USE_EXA
+    Bool              exa_force_create;
     XF86ModReqInfo    exaReq;
 #endif
 #ifdef USE_XAA
@@ -1004,6 +1006,7 @@ typedef struct {
     uint64_t vram_size;
     uint64_t gart_size;
     drmmode_rec drmmode;
+    int exa_low_vram_threshhold_mb;
 #else
     /* fake bool */
     Bool cs;
diff --git a/src/radeon_dri2.c b/src/radeon_dri2.c
index db46d27a..56c00a32 100644
--- a/src/radeon_dri2.c
+++ b/src/radeon_dri2.c
@@ -65,6 +65,8 @@ radeon_dri2_create_buffers(DrawablePtr drawable,
                            int count)
 {
     ScreenPtr pScreen = drawable->pScreen;
+    ScrnInfoPtr pScrn = xf86Screens[pScreen->myNum];
+    RADEONInfoPtr info = RADEONPTR(pScrn);
     BufferPtr buffers;
     struct dri2_buffer_priv *privates;
     PixmapPtr pixmap, depth_pixmap;
@@ -120,7 +122,9 @@ radeon_dri2_create_buffers(DrawablePtr drawable,
         if (attachments[i] == DRI2BufferDepth) {
             depth_pixmap = pixmap;
         }
+	info->exa_force_create = TRUE;
 	exaMoveInPixmap(pixmap);
+	info->exa_force_create = FALSE;
         driver_priv = exaGetPixmapDriverPrivate(pixmap);
 	r = radeon_gem_get_kernel_name(driver_priv->bo, &buffers[i].name);
 	if (r)
@@ -143,6 +147,8 @@ radeon_dri2_create_buffer(DrawablePtr drawable,
                           unsigned int format)
 {
     ScreenPtr pScreen = drawable->pScreen;
+    ScrnInfoPtr pScrn = xf86Screens[pScreen->myNum];
+    RADEONInfoPtr info = RADEONPTR(pScrn);
     BufferPtr buffers;
     struct dri2_buffer_priv *privates;
     PixmapPtr pixmap, depth_pixmap;
@@ -198,7 +204,9 @@ radeon_dri2_create_buffer(DrawablePtr drawable,
     if (attachment == DRI2BufferDepth) {
         depth_pixmap = pixmap;
     }
+    info->exa_force_create = TRUE;
     exaMoveInPixmap(pixmap);
+    info->exa_force_create = FALSE;
     driver_priv = exaGetPixmapDriverPrivate(pixmap);
     r = radeon_gem_get_kernel_name(driver_priv->bo, &buffers->name);
     if (r)
diff --git a/src/radeon_exa.c b/src/radeon_exa.c
index 99a93a4e..b2456c87 100644
--- a/src/radeon_exa.c
+++ b/src/radeon_exa.c
@@ -391,6 +391,12 @@ void *RADEONEXACreatePixmap(ScreenPtr pScreen, int size, int align)
     RADEONInfoPtr info = RADEONPTR(pScrn);
     struct radeon_exa_pixmap_priv *new_priv;
 
+    if (info->accel_state->exa->flags & EXA_MIXED_PIXMAPS) {
+        if (size != 0 && !info->exa_force_create &&
+	    info->vram_size <= (info->exa_low_vram_threshhold_mb*1024*1024))
+            return NULL;
+    }
+	    
     new_priv = xcalloc(1, sizeof(struct radeon_exa_pixmap_priv));
     if (!new_priv)
 	return NULL;
@@ -421,7 +427,13 @@ void *RADEONEXACreatePixmap2(ScreenPtr pScreen, int width, int height,
     uint32_t size;
     uint32_t tiling = 0;
     int pixmap_align = 0;
-    
+
+    if (info->accel_state->exa->flags & EXA_MIXED_PIXMAPS) {
+	if (width != 0 && height != 0 && !info->exa_force_create &&
+	    info->vram_size <= (info->exa_low_vram_threshhold_mb*1024*1024))
+            return NULL;
+    }
+
     if (usage_hint) {
 	if (info->allowColorTiling) {
     	    if (usage_hint & RADEON_CREATE_PIXMAP_TILING_MACRO)
diff --git a/src/radeon_kms.c b/src/radeon_kms.c
index 5a4255f9..e624f86d 100644
--- a/src/radeon_kms.c
+++ b/src/radeon_kms.c
@@ -67,6 +67,7 @@ const OptionInfoRec RADEONOptions_KMS[] = {
     { OPTION_DRI,            "DRI",       	 OPTV_BOOLEAN, {0}, FALSE },
     { OPTION_TVSTD,          "TVStandard",         OPTV_STRING,  {0}, FALSE },
     { OPTION_EXA_VSYNC,         "EXAVSync",        OPTV_BOOLEAN, {0}, FALSE },
+    { OPTION_EXA_LOW_VRAM,   "EXALowVRAM",	OPTV_INTEGER,   {0}, FALSE },
     { -1,                    NULL,               OPTV_NONE,    {0}, FALSE }
 };
 
@@ -450,6 +451,20 @@ Bool RADEONPreInit_KMS(ScrnInfoPtr pScrn, int flags)
 		       (unsigned long long)mminfo.vram_visible);
 	}
     }
+
+    info->exa_low_vram_threshhold_mb = 32;
+    if (xf86GetOptValInteger(info->Options, OPTION_EXA_LOW_VRAM,
+			     &(info->exa_low_vram_threshhold_mb))) {
+	if (info->exa_low_vram_threshhold_mb < 0 ||
+	    info->exa_low_vram_threshhold_mb > (info->vram_size * 1024 * 1024)) {
+	    xf86DrvMsg(pScrn->scrnIndex, X_ERROR,
+		       "Illegal Low VRAM limit selected %d, total %lld\n",
+		       info->exa_low_vram_threshhold_mb,
+		       info->vram_size / (1024*1024));
+	    info->exa_low_vram_threshhold_mb = 32;
+	}
+    }
+    
     RADEONSetPitch(pScrn);
 
     /* Set display resolution */
diff --git a/src/radeon_textured_video.c b/src/radeon_textured_video.c
index 39c75749..7396f6f0 100644
--- a/src/radeon_textured_video.c
+++ b/src/radeon_textured_video.c
@@ -349,7 +349,9 @@ RADEONPutImageTextured(ScrnInfoPtr pScrn,
 #ifdef USE_EXA
     if (info->useEXA) {
 	/* Force the pixmap into framebuffer so we can draw to it. */
+	info->exa_force_create = TRUE;
 	exaMoveInPixmap(pPriv->pPixmap);
+	info->exa_force_create = FALSE;
     }
 #endif