drm/i915/bdw: Add WT caching ability

I don't have any insight on what parts can do what. The docs do seem to
suggest WT caching works in at least the same manner as it does on
Haswell.

The addr = 0  is to shut up GCC:
drivers/gpu/drm/i915/i915_gem_gtt.c:80:7: warning: 'addr' may be used
uninitialized in this function [-Wmaybe-uninitialized]

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Reviewed-by: Brad Volkin <bradley.d.volkin@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index d61f6b1e83ac49107cacae4582a3883c749c7531..cc87130e9c7b82c5b764e9aa0ac7a9ef0e2f764b 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1836,12 +1836,13 @@ struct drm_i915_cmd_table {
 #define BLT_RING               (1<<BCS)
 #define VEBOX_RING             (1<<VECS)
 #define BSD2_RING              (1<<VCS2)
-#define HAS_BSD(dev)            (INTEL_INFO(dev)->ring_mask & BSD_RING)
+#define HAS_BSD(dev)           (INTEL_INFO(dev)->ring_mask & BSD_RING)
 #define HAS_BSD2(dev)          (INTEL_INFO(dev)->ring_mask & BSD2_RING)
-#define HAS_BLT(dev)            (INTEL_INFO(dev)->ring_mask & BLT_RING)
-#define HAS_VEBOX(dev)            (INTEL_INFO(dev)->ring_mask & VEBOX_RING)
-#define HAS_LLC(dev)            (INTEL_INFO(dev)->has_llc)
-#define HAS_WT(dev)            (IS_HASWELL(dev) && to_i915(dev)->ellc_size)
+#define HAS_BLT(dev)           (INTEL_INFO(dev)->ring_mask & BLT_RING)
+#define HAS_VEBOX(dev)         (INTEL_INFO(dev)->ring_mask & VEBOX_RING)
+#define HAS_LLC(dev)           (INTEL_INFO(dev)->has_llc)
+#define HAS_WT(dev)            ((IS_HASWELL(dev) || IS_BROADWELL(dev)) && \
+                                to_i915(dev)->ellc_size)
 #define I915_NEED_GFX_HWS(dev) (INTEL_INFO(dev)->need_gfx_hws)
 
 #define HAS_HW_CONTEXTS(dev)   (INTEL_INFO(dev)->gen >= 6)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 0d514ff9b94c4221ccf4ce853a7642a2715fb948..496916298e8a59ef89323e53a97a1beae44d909b 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -68,10 +68,19 @@ static inline gen8_gtt_pte_t gen8_pte_encode(dma_addr_t addr,
 {
        gen8_gtt_pte_t pte = valid ? _PAGE_PRESENT | _PAGE_RW : 0;
        pte |= addr;
-       if (level != I915_CACHE_NONE)
-               pte |= PPAT_CACHED_INDEX;
-       else
+
+       switch (level) {
+       case I915_CACHE_NONE:
                pte |= PPAT_UNCACHED_INDEX;
+               break;
+       case I915_CACHE_WT:
+               pte |= PPAT_DISPLAY_ELLC_INDEX;
+               break;
+       default:
+               pte |= PPAT_CACHED_INDEX;
+               break;
+       }
+
        return pte;
 }
 
@@ -1368,7 +1377,7 @@ static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
                (gen8_gtt_pte_t __iomem *)dev_priv->gtt.gsm + first_entry;
        int i = 0;
        struct sg_page_iter sg_iter;
-       dma_addr_t addr;
+       dma_addr_t addr = 0;
 
        for_each_sg_page(st->sgl, &sg_iter, st->nents, 0) {
                addr = sg_dma_address(sg_iter.sg) +