[coreboot] [PATCH]libpayload: memalign, take 2

[Patrick Georgi]

Hi there,

after the discussion on the list about memalign, I wrote version that's
better integrated with the other memory management stuff, and doesn't
come with its own pool allocator.

Regards,
Patrick Georgi

Signed-off-by: Patrick Georgi

Index: include/libpayload.h
===================================================================
--- include/libpayload.h	(revision 3536)
+++ include/libpayload.h	(working copy)
@@ -164,6 +164,7 @@
 void *malloc(size_t size);
 void *calloc(size_t nmemb, size_t size);
 void *realloc(void *ptr, size_t size);
+void *memalign(size_t align, size_t size);

/* libc/exec.c */
 int exec(long addr, int argc, char **argv);
Index: libc/malloc.c
===================================================================
--- libc/malloc.c	(revision 3536)
+++ libc/malloc.c	(working copy)
@@ -72,7 +72,7 @@
    *((hdrtype_t *) hstart) = FREE_BLOCK(size);
 }

-static void *alloc(int len)
+static void *alloc(int len, int align)
 {
    hdrtype_t header;
    void *ptr = hstart;
@@ -92,13 +92,20 @@
    	header = *((hdrtype_t *) ptr);
    	int size = SIZE(header);

-		if (!HAS_MAGIC(header) || size == 0) {
+		if (!HAS_MAGIC(header)) {
    		printf("memory allocator panic.\n");
    		halt();
    	}

if (header & FLAG_FREE) {
-			if (len <= size) {
+			int realaddr = (int)(ptr + HDRSIZE);
+			int overhead = ((realaddr+align-1) & ~(align-1)) - realaddr;
+			if (len + overhead <= size) {
+				if (overhead != 0) {
+					*((hdrtype_t *) ptr) = FREE_BLOCK(overhead - HDRSIZE);
+					ptr += overhead;
+					size -= overhead;
+				}
    			void *nptr = ptr + (HDRSIZE + len);
    			int nsize = size - (HDRSIZE + len);

@@ -186,13 +193,13 @@

void *malloc(size_t size)
 {
-	return alloc(size);
+	return alloc(size, 1);
 }

void *calloc(size_t nmemb, size_t size)
 {
    size_t total = nmemb * size;
-	void *ptr = alloc(total);
+	void *ptr = alloc(total, 1);

if (ptr)
    	memset(ptr, 0, total);
@@ -206,7 +213,7 @@
    unsigned int osize;

if (ptr == NULL)
-		return alloc(size);
+		return alloc(size, 1);

pptr = ptr - HDRSIZE;

@@ -222,7 +229,7 @@
     * reallocated the new space.
     */
    free(ptr);
-	ret = alloc(size);
+	ret = alloc(size, 1);

/*
     * if ret == NULL, then doh - failure.
@@ -237,6 +244,11 @@
    return ret;
 }

+void *memalign(size_t align, size_t size)
+{
+	return alloc(size, align);
+}
+
 /* This is for debugging purposes. */
 #ifdef TEST
 void print_malloc_map(void)