svn commit: r261530 - head/lib/libstand

[Ian Lepore]

Author: ian
Date: Wed Feb  5 22:53:58 2014
New Revision: 261530
URL: http://svnweb.freebsd.org/changeset/base/261530

Log:
  Set the malloc alignment to 64 bytes on platforms that use the U-Boot API
  device drivers.  Recent versions of u-boot run with the MMU enabled, and
  require DMA-based I/O to be aligned to cache line boundaries.
  
  These changes are based on a patch originally submitted by Juergen Weiss,
  but I reworked them and thus any problems are purely my fault.
  
  Submitted by:	"Juergen Weiss" <weiss at uni-mainz.de>
  Reviewed by:	imp, nwhitehorn, jhb

Modified:
  head/lib/libstand/sbrk.c
  head/lib/libstand/zalloc.c
  head/lib/libstand/zalloc_defs.h
  head/lib/libstand/zalloc_mem.h

Modified: head/lib/libstand/sbrk.c
==============================================================================
--- head/lib/libstand/sbrk.c	Wed Feb  5 22:27:49 2014	(r261529)
+++ head/lib/libstand/sbrk.c	Wed Feb  5 22:53:58 2014	(r261530)
@@ -33,6 +33,7 @@ __FBSDID("$FreeBSD$");
 
 #include <string.h>
 #include "stand.h"
+#include "zalloc_defs.h"
 
 static size_t	maxheap, heapsize = 0;
 static void	*heapbase;
@@ -40,8 +41,9 @@ static void	*heapbase;
 void
 setheap(void *base, void *top)
 {
-    /* Align start address to 16 bytes for the malloc code. Sigh. */
-    heapbase = (void *)(((uintptr_t)base + 15) & ~15);
+    /* Align start address for the malloc code.  Sigh. */
+    heapbase = (void *)(((uintptr_t)base + MALLOCALIGN_MASK) & 
+        ~MALLOCALIGN_MASK);
     maxheap = (char *)top - (char *)heapbase;
 }
 

Modified: head/lib/libstand/zalloc.c
==============================================================================
--- head/lib/libstand/zalloc.c	Wed Feb  5 22:27:49 2014	(r261529)
+++ head/lib/libstand/zalloc.c	Wed Feb  5 22:53:58 2014	(r261530)
@@ -71,6 +71,15 @@ __FBSDID("$FreeBSD$");
 #include "zalloc_defs.h"
 
 /*
+ * Objects in the pool must be aligned to at least the size of struct MemNode.
+ * They must also be aligned to MALLOCALIGN, which should normally be larger
+ * than the struct, so assert that to be so at compile time.
+ */
+typedef char assert_align[(sizeof(struct MemNode) <= MALLOCALIGN) ? 1 : -1];
+
+#define	MEMNODE_SIZE_MASK	MALLOCALIGN_MASK
+
+/*
  * znalloc() -	allocate memory (without zeroing) from pool.  Call reclaim
  *		and retry if appropriate, return NULL if unable to allocate
  *		memory.

Modified: head/lib/libstand/zalloc_defs.h
==============================================================================
--- head/lib/libstand/zalloc_defs.h	Wed Feb  5 22:27:49 2014	(r261529)
+++ head/lib/libstand/zalloc_defs.h	Wed Feb  5 22:53:58 2014	(r261530)
@@ -52,18 +52,26 @@
 #define BLKEXTENDMASK	(BLKEXTEND - 1)
 
 /*
- * required malloc alignment.  Just hardwire to 16.
+ * Required malloc alignment.
  *
- * Note: if we implement a more sophisticated realloc, we should ensure that
- * MALLOCALIGN is at least as large as MemNode.
+ * Embedded platforms using the u-boot API drivers require that all I/O buffers
+ * be on a cache line sized boundary.  The worst case size for that is 64 bytes.
+ * For other platforms, 16 bytes works fine.  The alignment also must be at
+ * least sizeof(struct MemNode); this is asserted in zalloc.c.
  */
 
+#if defined(__arm__) || defined(__mips__) || defined(__powerpc__)
+#define	MALLOCALIGN		64
+#else
+#define	MALLOCALIGN		16
+#endif
+#define	MALLOCALIGN_MASK	(MALLOCALIGN - 1)
+
 typedef struct Guard {
     size_t	ga_Bytes;
     size_t	ga_Magic;	/* must be at least 32 bits */
 } Guard;
 
-#define MALLOCALIGN	16
 #define GAMAGIC		0x55FF44FD
 #define GAFREE		0x5F54F4DF
 

Modified: head/lib/libstand/zalloc_mem.h
==============================================================================
--- head/lib/libstand/zalloc_mem.h	Wed Feb  5 22:27:49 2014	(r261529)
+++ head/lib/libstand/zalloc_mem.h	Wed Feb  5 22:53:58 2014	(r261530)
@@ -48,8 +48,6 @@ typedef struct MemPool {
     uintptr_t		mp_Used;
 } MemPool;
 
-#define MEMNODE_SIZE_MASK       ((sizeof(MemNode) <= 8) ? 7 : 15)
-
 #define ZNOTE_FREE	0
 #define ZNOTE_REUSE	1