From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Mon, 7 Dec 2020 20:55:13 +0000 (-0500)
Subject: maple_tree: Remove slot shift calculations.
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=b81fb7bd008a267c1260772ee3347935a0bdac4b;p=users%2Fjedix%2Flinux-maple.git

maple_tree: Remove slot shift calculations.

Slot shift is always 3 now, so don't calculate it.

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index f6cbf8d92fcc..bdc2a1c1b64b 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -259,13 +259,7 @@ static inline bool mt_is_alloc(struct maple_tree *mt)
 	return (mt->ma_flags & MAPLE_ALLOC_RANGE);
 }
 
-
-static inline unsigned int mte_parent_shift(unsigned long parent)
-{
-	if (!(parent & 2))
-		return 2; // maple_range_16
-	return 3;
-}
+#define MAPLE_PARENT_SHIFT 3
 
 static inline enum maple_type mte_parent_range_enum(unsigned long parent)
 {
@@ -287,12 +281,10 @@ static inline enum maple_type mas_parent_enum(struct ma_state *mas,
 		struct maple_enode *node)
 {
 	unsigned long parent = 6;
-	unsigned long slot_shift;
 
-	if (!mte_is_root(mas->node)) {
+	if (likely(!mte_is_root(mas->node))) {
 		parent = (unsigned long) mte_to_node(node)->parent;
-		slot_shift = mte_parent_shift(parent);
-		parent &= (1 << slot_shift) - 1;
+		parent &= (1 << MAPLE_PARENT_SHIFT) - 1;
 	}
 
 	if (mt_is_alloc(mas->tree))
@@ -310,7 +302,7 @@ static inline enum maple_type mas_parent_enum(struct ma_state *mas,
  * Type is encoded in the enode->parent
  * bit 0: 1 = root, 0 otherwise
  * bit 1: Reserved.
- * bit 2: 0 = range 32, 1 = [a]range 64 | lowest bit of range_16's slot.
+ * bit 2: 0 = range 32, 1 = [a]range 64
  *
  * Slot number is encoded in the enode->parent
  * range_32, slot number is encoded in bits 3-6
@@ -321,22 +313,20 @@ static inline void mte_set_parent(struct maple_enode *enode,
 				 unsigned char slot)
 {
 	unsigned long bitmask = 0x78;
-	unsigned long slot_shift = 3;
 	unsigned long val = (unsigned long) parent;
 	unsigned long type = 0;
 
 	switch (mte_node_type(parent)) {
 	case maple_range_64:
 	case maple_arange_64:
-		type |= 4;
-		type |= 2;
+		type = 6;
 		break;
 	default:
 		break;
 	}
 
 	val &= ~bitmask; // Remove any old slot number.
-	val |= (slot << slot_shift); // Set the slot.
+	val |= (slot << MAPLE_PARENT_SHIFT); // Set the slot.
 	val |= type;
 	mte_to_node(enode)->parent = ma_parent_ptr(val);
 }
@@ -351,12 +341,11 @@ static inline unsigned int mte_parent_slot(const struct maple_enode *enode)
 {
 	unsigned long bitmask = 0x7C;
 	unsigned long val = (unsigned long) mte_to_node(enode)->parent;
-	unsigned long slot_shift = mte_parent_shift(val);
 
 	if (val & 1)
 		return 0; // Root.
 
-	return (val & bitmask) >> slot_shift;
+	return (val & bitmask) >> MAPLE_PARENT_SHIFT;
 }
 
 /*