drm/vmwgfx: Get maximum mob size from register SVGA_REG_MOB_MAX_SIZE

This patch queries the register SVGA_REG_MOB_MAX_SIZE for the
maximum size of a single mob.
Signed-off-by: Charmaine Lee <charmainel@vmware.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>

drivers/gpu/drm/vmwgfx/svga_reg.h

@@ -169,10 +169,17 @@ enum {
    SVGA_REG_TRACES = 45,            /* Enable trace-based updates even when FIFO is on */
    SVGA_REG_GMRS_MAX_PAGES = 46,    /* Maximum number of 4KB pages for all GMRs */
    SVGA_REG_MEMORY_SIZE = 47,       /* Total dedicated device memory excluding FIFO */
+   SVGA_REG_COMMAND_LOW = 48,       /* Lower 32 bits and submits commands */
+   SVGA_REG_COMMAND_HIGH = 49,      /* Upper 32 bits of command buffer PA */
    SVGA_REG_MAX_PRIMARY_BOUNDING_BOX_MEM = 50,   /* Max primary memory */
    SVGA_REG_SUGGESTED_GBOBJECT_MEM_SIZE_KB = 51, /* Suggested limit on mob mem */
    SVGA_REG_DEV_CAP = 52,           /* Write dev cap index, read value */
-   SVGA_REG_TOP = 53,               /* Must be 1 more than the last register */
+   SVGA_REG_CMD_PREPEND_LOW = 53,
+   SVGA_REG_CMD_PREPEND_HIGH = 54,
+   SVGA_REG_SCREENTARGET_MAX_WIDTH = 55,
+   SVGA_REG_SCREENTARGET_MAX_HEIGHT = 56,
+   SVGA_REG_MOB_MAX_SIZE = 57,
+   SVGA_REG_TOP = 58,               /* Must be 1 more than the last register */
 
    SVGA_PALETTE_BASE = 1024,        /* Base of SVGA color map */
    /* Next 768 (== 256*3) registers exist for colormap */

drivers/gpu/drm/vmwgfx/vmwgfx_drv.c

@@ -667,6 +667,7 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
 		dev_priv->memory_size = 512*1024*1024;
 	}
 	dev_priv->max_mob_pages = 0;
+	dev_priv->max_mob_size = 0;
 	if (dev_priv->capabilities & SVGA_CAP_GBOBJECTS) {
 		uint64_t mem_size =
 			vmw_read(dev_priv,
@@ -676,6 +677,8 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
 		dev_priv->prim_bb_mem =
 			vmw_read(dev_priv,
 				 SVGA_REG_MAX_PRIMARY_BOUNDING_BOX_MEM);
+		dev_priv->max_mob_size =
+			vmw_read(dev_priv, SVGA_REG_MOB_MAX_SIZE);
 	} else
 		dev_priv->prim_bb_mem = dev_priv->vram_size;
 

drivers/gpu/drm/vmwgfx/vmwgfx_drv.h

@@ -386,6 +386,7 @@ struct vmw_private {
 	uint32_t max_gmr_ids;
 	uint32_t max_gmr_pages;
 	uint32_t max_mob_pages;
+	uint32_t max_mob_size;
 	uint32_t memory_size;
 	bool has_gmr;
 	bool has_mob;

drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c

@@ -102,6 +102,9 @@ int vmw_getparam_ioctl(struct drm_device *dev, void *data,
 		vmw_fp->gb_aware = true;
 		param->value = dev_priv->max_mob_pages * PAGE_SIZE;
 		break;
+	case DRM_VMW_PARAM_MAX_MOB_SIZE:
+		param->value = dev_priv->max_mob_size;
+		break;
 	default:
 		DRM_ERROR("Illegal vmwgfx get param request: %d\n",
 			  param->param);

include/uapi/drm/vmwgfx_drm.h

@@ -87,6 +87,7 @@
 #define DRM_VMW_PARAM_MAX_SURF_MEMORY  7
 #define DRM_VMW_PARAM_3D_CAPS_SIZE     8
 #define DRM_VMW_PARAM_MAX_MOB_MEMORY   9
+#define DRM_VMW_PARAM_MAX_MOB_SIZE     10
 
 /**
  * struct drm_vmw_getparam_arg