Skip to contentSkip to conversation

drm/i915/bdw: Add WT caching ability

PATCH In review Ben Widawsky 2 participants 3 messages Mar 29, 2014

Subsystems (2)
lore
Share & tools
lore
#0 lore raw

PATCH 1/2 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 doesn't 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]

---
 drivers/gpu/drm/i915/i915_drv.h     | 11 ++++++-----
 drivers/gpu/drm/i915/i915_gem_gtt.c | 17 +++++++++++++----
 2 files changed, 19 insertions(+), 9 deletions(-)
drivers/gpu/drm/i915/i915_drv.h +6 -5
index e23bb73..896fe8e 100644
@@ -1822,11 +1822,12 @@ struct drm_i915_cmd_table {
 #define BSD_RING		(1<<VCS)
 #define BLT_RING		(1<<BCS)
 #define VEBOX_RING		(1<<VECS)
-#define HAS_BSD(dev)            (INTEL_INFO(dev)->ring_mask & BSD_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_BSD(dev)		(INTEL_INFO(dev)->ring_mask & BSD_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) || 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)
drivers/gpu/drm/i915/i915_gem_gtt.c +13 -4
index 4467974..10d00ee 100644
@@ -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;
 }
 
@@ -1367,7 +1376,7 @@ 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) +
Signature · 1 line
1.9.1
#1 lore raw

PATCH 2/2 drm/i915/bdw: enable eDRAM.

The same register exists for querying and programming eDRAM AKA eLLC. So we can simply use it. For now, use all the same defaults as we had for Haswell, since like Haswell, I have no further details.

I do not actually have a part with eDRAM, so I cannot test this.

---
 drivers/gpu/drm/i915/intel_uncore.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/gpu/drm/i915/intel_uncore.c +1 -1
index 823d699..f5e7240 100644
@@ -370,7 +370,7 @@ void intel_uncore_early_sanitize(struct drm_device *dev)
 	if (HAS_FPGA_DBG_UNCLAIMED(dev))
 		__raw_i915_write32(dev_priv, FPGA_DBG, FPGA_DBG_RM_NOCLAIM);
 
-	if (IS_HASWELL(dev) &&
+	if ((IS_HASWELL(dev) || IS_BROADWELL(dev)) &&
 	    (__raw_i915_read32(dev_priv, HSW_EDRAM_PRESENT) == 1)) {
 		/* The docs do not explain exactly how the calculation can be
 		 * made. It is somewhat guessable, but for now, it's always
Signature · 1 line
1.9.1
#2 lore raw
In reply to Ben Widawsky
Quoted 4 lines · Ben Widawsky

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 doesn't on Haswell.

That's a freudian slip... s/doesn't/does/

Quoted 75 lines

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]

---
 drivers/gpu/drm/i915/i915_drv.h     | 11 ++++++-----
 drivers/gpu/drm/i915/i915_gem_gtt.c | 17 +++++++++++++----
 2 files changed, 19 insertions(+), 9 deletions(-)
drivers/gpu/drm/i915/i915_drv.h +6 -5
index e23bb73..896fe8e 100644
@@ -1822,11 +1822,12 @@ struct drm_i915_cmd_table {
 #define BSD_RING		(1<<VCS)
 #define BLT_RING		(1<<BCS)
 #define VEBOX_RING		(1<<VECS)
-#define HAS_BSD(dev)            (INTEL_INFO(dev)->ring_mask & BSD_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_BSD(dev)		(INTEL_INFO(dev)->ring_mask & BSD_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) || 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)
drivers/gpu/drm/i915/i915_gem_gtt.c +13 -4
index 4467974..10d00ee 100644
@@ -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;
 }
 
@@ -1367,7 +1376,7 @@ 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) +
Signature · 6 lines
1.9.1

_______________________________________________
Intel-gfx mailing list
[email protected]
http://lists.freedesktop.org/mailman/listinfo/intel-gfx
Signature · 1 line
Ben Widawsky, Intel Open Source Technology Center