libubb/physmem.c: new function physmem_flush to flush cached writes to memory

This is mainly a wrapper for the "cacheflush" system call.

libubb/Makefile

@@ -15,7 +15,7 @@ TARGET = mipsel-openwrt-linux-
 CC = $(TARGET)gcc
 LD = $(TARGET)ld
 
-CFLAGS = -g -Wall -fPIC -Iinclude
+CFLAGS = -g -Wall -fPIC -march=mips32 -Iinclude
 LIB = libubb.a
 SHLIB = libubb.so
 

libubb/include/ubb/physmem.h

@@ -0,0 +1,24 @@
+/*
+ * physmem.h - Physical memory translator and allocator
+ *
+ * Written 2013 by Werner Almesberger
+ * Copyright 2013 Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef UBB_PHYSMEM_H
+#define	UBB_PHYSMEM_H
+
+#include <sys/types.h>
+
+
+void *physmem_malloc(size_t size);
+void *physmem_calloc(size_t size);
+unsigned long physmem_xlat(void *v);
+int physmem_flush(const void *data, size_t size);
+
+#endif /* !UBB_PHYSMEM_H */

libubb/physmem.c

@@ -19,6 +19,7 @@
 #include <fcntl.h>
 #include <errno.h>
 #include <sys/types.h>
+#include <asm/cachectl.h>
 
 #include <ubb/physmem.h>
 
@@ -34,6 +35,9 @@
 #define	ALIGN		32	/* DMA transfer size */
 
 
+extern int cacheflush(char *addr, int nbytes, int cache);
+
+
 static void *align_brk(int alignment)
 {
 	void *initial;
@@ -138,3 +142,12 @@ unsigned long physmem_xlat(void *v)
 	close(fd);
 	return res;
 }
+
+
+int physmem_flush(const void *v, size_t size)
+{
+	if (cacheflush((void *) v, size, DCACHE))
+		return -1;
+	asm("sync");	/* flush the write buffer */
+	return 0;
+}