[Intel-gfx] [PATCH 1/2] drm/i915: Redefine ptr_pack_bits() and friends

[Chris Wilson]

Rebrand the current (pointer | bits) pack/unpack utility macros as
explicit bit twiddling for PAGE_SIZE so that we can use the more
flexible underlying macros for different bits.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_cmd_parser.c |  2 +-
 drivers/gpu/drm/i915/i915_gem.c        |  6 +++---
 drivers/gpu/drm/i915/i915_utils.h      | 19 +++++++++++++------
 3 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
index 7af100f84410..1b69a1f9a1ea 100644
--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
+++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
@@ -1284,7 +1284,7 @@ int intel_engine_cmd_parser(struct intel_engine_cs *engine,
 
 		if (*cmd == MI_BATCH_BUFFER_END) {
 			if (needs_clflush_after) {
-				void *ptr = ptr_mask_bits(shadow_batch_obj->mm.mapping);
+				void *ptr = page_mask_bits(shadow_batch_obj->mm.mapping);
 				drm_clflush_virt_range(ptr,
 						       (void *)(cmd + 1) - ptr);
 			}
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index bbc6f1c9f175..82638895ad20 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2228,7 +2228,7 @@ void __i915_gem_object_put_pages(struct drm_i915_gem_object *obj,
 	if (obj->mm.mapping) {
 		void *ptr;
 
-		ptr = ptr_mask_bits(obj->mm.mapping);
+		ptr = page_mask_bits(obj->mm.mapping);
 		if (is_vmalloc_addr(ptr))
 			vunmap(ptr);
 		else
@@ -2560,7 +2560,7 @@ void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj,
 	}
 	GEM_BUG_ON(!obj->mm.pages);
 
-	ptr = ptr_unpack_bits(obj->mm.mapping, has_type);
+	ptr = page_unpack_bits(obj->mm.mapping, has_type);
 	if (ptr && has_type != type) {
 		if (pinned) {
 			ret = -EBUSY;
@@ -2582,7 +2582,7 @@ void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj,
 			goto err_unpin;
 		}
 
-		obj->mm.mapping = ptr_pack_bits(ptr, type);
+		obj->mm.mapping = page_pack_bits(ptr, type);
 	}
 
 out_unlock:
diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h
index c5455d36b617..67b1a1897310 100644
--- a/drivers/gpu/drm/i915/i915_utils.h
+++ b/drivers/gpu/drm/i915/i915_utils.h
@@ -70,20 +70,27 @@
 #define overflows_type(x, T) \
 	(sizeof(x) > sizeof(T) && (x) >> (sizeof(T) * BITS_PER_BYTE))
 
-#define ptr_mask_bits(ptr) ({						\
+#define ptr_mask_bits(ptr, n) ({					\
 	unsigned long __v = (unsigned long)(ptr);			\
-	(typeof(ptr))(__v & PAGE_MASK);					\
+	(typeof(ptr))(__v & -BIT(n));					\
 })
 
-#define ptr_unpack_bits(ptr, bits) ({					\
+#define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
+
+#define ptr_unpack_bits(ptr, bits, n) ({				\
 	unsigned long __v = (unsigned long)(ptr);			\
-	(bits) = __v & ~PAGE_MASK;					\
-	(typeof(ptr))(__v & PAGE_MASK);					\
+	(bits) = __v & (BIT(n) - 1);					\
+	(typeof(ptr))(__v & -BIT(n));					\
 })
 
-#define ptr_pack_bits(ptr, bits)					\
+#define ptr_pack_bits(ptr, bits, n)					\
 	((typeof(ptr))((unsigned long)(ptr) | (bits)))
 
+#define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
+#define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
+#define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
+#define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
+
 #define ptr_offset(ptr, member) offsetof(typeof(*(ptr)), member)
 
 #define fetch_and_zero(ptr) ({						\
-- 
2.11.0