diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/boot/Makefile | 2 | ||||
| -rw-r--r-- | arch/powerpc/boot/simple_alloc.c | 149 |
2 files changed, 150 insertions, 1 deletions
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile index 62435d951db..9731c25c54a 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 00000000000..cfe3a7505ba --- /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); +} |