[POWERPC] Add simple memory allocator to bootwrapper

Provide primitive malloc, free, and realloc functions for bootwrapper.

Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

2 files changed, 150 insertions, 1 deletions

diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index 62435d951dbd..9731c25c54a1 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -41,7 +41,7 @@ $(addprefix $(obj)/,$(zlib) main.o): $(addprefix $(obj)/,$(zliblinuxheader)) \
                 $(addprefix $(obj)/,$(zlibheader))
 
 src-wlib := string.S stdio.c main.c flatdevtree.c flatdevtree_misc.c \
-                ns16550.c serial.c div64.S util.S $(zlib)
+                ns16550.c serial.c simple_alloc.c div64.S util.S $(zlib)
 src-plat := of.c
 src-boot := crt0.S $(src-wlib) $(src-plat) empty.c
 
diff --git a/arch/powerpc/boot/simple_alloc.c b/arch/powerpc/boot/simple_alloc.c
new file mode 100644
index 000000000000..cfe3a7505ba0
--- /dev/null
+++ b/arch/powerpc/boot/simple_alloc.c
@@ -0,0 +1,149 @@
+/*
+ * Implement primitive realloc(3) functionality.
+ *
+ * Author: Mark A. Greer <mgreer@mvista.com>
+ *
+ * 2006 (c) MontaVista, Software, Inc.  This file is licensed under
+ * the terms of the GNU General Public License version 2.  This program
+ * is licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ */
+
+#include <stddef.h>
+#include "types.h"
+#include "page.h"
+#include "string.h"
+#include "ops.h"
+
+#define ENTRY_BEEN_USED 0x01
+#define ENTRY_IN_USE    0x02
+
+static struct alloc_info {
+        u32     flags;
+        u32     base;
+        u32     size;
+} *alloc_tbl;
+
+static u32 tbl_entries;
+static u32 alloc_min;
+static u32 next_base;
+static u32 space_left;
+
+/*
+ * First time an entry is used, its base and size are set.
+ * An entry can be freed and re-malloc'd but its base & size don't change.
+ * Should be smart enough for needs of bootwrapper.
+ */
+static void *simple_malloc(u32 size)
+{
+        u32 i;
+        struct alloc_info *p = alloc_tbl;
+
+        if (size == 0)
+                goto err_out;
+
+        size = _ALIGN_UP(size, alloc_min);
+
+        for (i=0; i<tbl_entries; i++, p++)
+                if (!(p->flags & ENTRY_BEEN_USED)) { /* never been used */
+                        if (size <= space_left) {
+                                p->base = next_base;
+                                p->size = size;
+                                p->flags = ENTRY_BEEN_USED | ENTRY_IN_USE;
+                                next_base += size;
+                                space_left -= size;
+                                return (void *)p->base;
+                        }
+                        goto err_out; /* not enough space left */
+                }
+                /* reuse an entry keeping same base & size */
+                else if (!(p->flags & ENTRY_IN_USE) && (size <= p->size)) {
+                        p->flags |= ENTRY_IN_USE;
+                        return (void *)p->base;
+                }
+err_out:
+        return NULL;
+}
+
+static struct alloc_info *simple_find_entry(void *ptr)
+{
+        u32 i;
+        struct alloc_info *p = alloc_tbl;
+
+        for (i=0; i<tbl_entries; i++,p++) {
+                if (!(p->flags & ENTRY_BEEN_USED))
+                        break;
+                if ((p->flags & ENTRY_IN_USE) && (p->base == (u32)ptr))
+                        return p;
+        }
+        return NULL;
+}
+
+static void simple_free(void *ptr)
+{
+        struct alloc_info *p = simple_find_entry(ptr);
+
+        if (p != NULL)
+                p->flags &= ~ENTRY_IN_USE;
+}
+
+/*
+ * Change size of area pointed to by 'ptr' to 'size'.
+ * If 'ptr' is NULL, then its a malloc().  If 'size' is 0, then its a free().
+ * 'ptr' must be NULL or a pointer to a non-freed area previously returned by
+ * simple_realloc() or simple_malloc().
+ */
+static void *simple_realloc(void *ptr, unsigned long size)
+{
+        struct alloc_info *p;
+        void *new;
+
+        if (size == 0) {
+                simple_free(ptr);
+                return NULL;
+        }
+
+        if (ptr == NULL)
+                return simple_malloc(size);
+
+        p = simple_find_entry(ptr);
+        if (p == NULL) /* ptr not from simple_malloc/simple_realloc */
+                return NULL;
+        if (size <= p->size) /* fits in current block */
+                return ptr;
+
+        new = simple_malloc(size);
+        memcpy(new, ptr, p->size);
+        simple_free(ptr);
+        return new;
+}
+
+/*
+ * Returns addr of first byte after heap so caller can see if it took
+ * too much space.  If so, change args & try again.
+ */
+void *simple_alloc_init(char *base, u32 heap_size, u32 granularity,
+                u32 max_allocs)
+{
+        u32 heap_base, tbl_size;
+
+        heap_size = _ALIGN_UP(heap_size, granularity);
+        alloc_min = granularity;
+        tbl_entries = max_allocs;
+
+        tbl_size = tbl_entries * sizeof(struct alloc_info);
+
+        alloc_tbl = (struct alloc_info *)_ALIGN_UP((unsigned long)base, 8);
+        memset(alloc_tbl, 0, tbl_size);
+
+        heap_base = _ALIGN_UP((u32)alloc_tbl + tbl_size, alloc_min);
+
+        next_base = heap_base;
+        space_left = heap_size;
+
+        platform_ops.malloc = simple_malloc;
+        platform_ops.free = simple_free;
+        platform_ops.realloc = simple_realloc;
+
+        return (void *)(heap_base + heap_size);
+}