memranges: Change align attribute to be log2 of required alignment

This change updates the align attribute of memranges to be represented
as log2 of the required alignment. This makes it consistent with how
alignment is stored in struct resource as well.

Additionally, since memranges only allow power of 2 alignments, this
change allows getting rid of checks at runtime and hence failure cases
for non-power of 2 alignments.

This change also updates the type of align to be unsigned char.

BUG=b:149186922

Signed-off-by: Furquan Shaikh <furquan@google.com>
Change-Id: Ie4d3868cdff55b2c7908b9b3ccd5f30a5288e62f
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39810
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 10 insertions, 19 deletions

diff --git a/src/lib/memrange.c b/src/lib/memrange.c
index 5fb40dfca7..fd7a4d6489 100644
--- a/src/lib/memrange.c
+++ b/src/lib/memrange.c
@@ -230,12 +230,12 @@ static void do_action(struct memranges *ranges,
 	if (size == 0)
 		return;
 
-	/* The addresses are aligned to 4096 bytes: the begin address is
+	/* The addresses are aligned to (1ULL << ranges->align): the begin address is
 	 * aligned down while the end address is aligned up to be conservative
 	 * about the full range covered. */
-	begin = ALIGN_DOWN(base, ranges->align);
+	begin = ALIGN_DOWN(base, POWER_OF_2(ranges->align));
 	end = begin + size + (base - begin);
-	end = ALIGN_UP(end, ranges->align) - 1;
+	end = ALIGN_UP(end, POWER_OF_2(ranges->align)) - 1;
 	action(ranges, begin, end, tag);
 }
 
@@ -294,13 +294,10 @@ void memranges_add_resources(struct memranges *ranges,
 
 void memranges_init_empty_with_alignment(struct memranges *ranges,
 					 struct range_entry *to_free,
-					 size_t num_free, size_t align)
+					 size_t num_free, unsigned char align)
 {
 	size_t i;
 
-	/* Alignment must be a power of 2. */
-	assert(IS_POWER_OF_2(align));
-
 	ranges->entries = NULL;
 	ranges->free_list = NULL;
 	ranges->align = align;
@@ -311,7 +308,7 @@ void memranges_init_empty_with_alignment(struct memranges *ranges,
 
 void memranges_init_with_alignment(struct memranges *ranges,
 				   unsigned long mask, unsigned long match,
-				   unsigned long tag, size_t align)
+				   unsigned long tag, unsigned char align)
 {
 	memranges_init_empty_with_alignment(ranges, NULL, 0, align);
 	memranges_add_resources(ranges, mask, match, tag);
@@ -395,7 +392,7 @@ struct range_entry *memranges_next_entry(struct memranges *ranges,
  * required alignment, is big enough, does not exceed the limit and has a matching tag. */
 static const struct range_entry *memranges_find_entry(struct memranges *ranges,
 						      resource_t limit, resource_t size,
-						      size_t align, unsigned long tag)
+						      unsigned char align, unsigned long tag)
 {
 	const struct range_entry *r;
 	resource_t base, end;
@@ -403,18 +400,12 @@ static const struct range_entry *memranges_find_entry(struct memranges *ranges,
 	if (size == 0)
 		return NULL;
 
-	if (!IS_POWER_OF_2(align))
-		return NULL;
-
-	if (!IS_ALIGNED(align, ranges->align))
-		return NULL;
-
 	memranges_each_entry(r, ranges) {
 
 		if (r->tag != tag)
 			continue;
 
-		base = ALIGN_UP(r->begin, align);
+		base = ALIGN_UP(r->begin, POWER_OF_2(align));
 		end = base + size - 1;
 
 		if (end > r->end)
@@ -429,8 +420,8 @@ static const struct range_entry *memranges_find_entry(struct memranges *ranges,
 	return NULL;
 }
 
-bool memranges_steal(struct memranges *ranges, resource_t limit, resource_t size, size_t align,
-		     unsigned long tag, resource_t *stolen_base)
+bool memranges_steal(struct memranges *ranges, resource_t limit, resource_t size,
+			unsigned char align, unsigned long tag, resource_t *stolen_base)
 {
 	resource_t base;
 	const struct range_entry *r = memranges_find_entry(ranges, limit, size, align, tag);
@@ -438,7 +429,7 @@ bool memranges_steal(struct memranges *ranges, resource_t limit, resource_t size
 	if (r == NULL)
 		return false;
 
-	base = ALIGN_UP(r->begin, align);
+	base = ALIGN_UP(r->begin, POWER_OF_2(align));
 
 	memranges_create_hole(ranges, base, size);
 	*stolen_base = base;