[PATCH 19/29] Staging: yaffs2: yaffs_packedtags2: Add files

[Tracey Dent <tdent48227@gmail.com>]

Adding files to yaffs2 directory.

Signed-off-by: Tracey Dent <tdent48227@gmail.com>
---
 drivers/staging/yaffs2/yaffs_packedtags2.c |  198 ++++++++++++++++++++++++++++
 drivers/staging/yaffs2/yaffs_packedtags2.h |   43 ++++++
 2 files changed, 241 insertions(+), 0 deletions(-)
 create mode 100644 drivers/staging/yaffs2/yaffs_packedtags2.c
 create mode 100644 drivers/staging/yaffs2/yaffs_packedtags2.h

diff --git a/drivers/staging/yaffs2/yaffs_packedtags2.c b/drivers/staging/yaffs2/yaffs_packedtags2.c
new file mode 100644
index 0000000..4873f78
--- /dev/null
+++ b/drivers/staging/yaffs2/yaffs_packedtags2.c
@@ -0,0 +1,198 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_packedtags2.h"
+#include "yportenv.h"
+#include "yaffs_trace.h"
+#include "yaffs_tagsvalidity.h"
+
+/* This code packs a set of extended tags into a binary structure for
+ * NAND storage
+ */
+
+/* Some of the information is "extra" struff which can be packed in to
+ * speed scanning
+ * This is defined by having the EXTRA_HEADER_INFO_FLAG set.
+ */
+
+/* Extra flags applied to chunk_id */
+
+#define EXTRA_HEADER_INFO_FLAG	0x80000000
+#define EXTRA_SHRINK_FLAG	0x40000000
+#define EXTRA_SHADOWS_FLAG	0x20000000
+#define EXTRA_SPARE_FLAGS	0x10000000
+
+#define ALL_EXTRA_FLAGS		0xF0000000
+
+/* Also, the top 4 bits of the object Id are set to the object type. */
+#define EXTRA_OBJECT_TYPE_SHIFT (28)
+#define EXTRA_OBJECT_TYPE_MASK  ((0x0F) << EXTRA_OBJECT_TYPE_SHIFT)
+
+
+static void yaffs_dump_packed_tags2_tags_only(const yaffs_packed_tags2_tags_only *ptt)
+{
+	T(YAFFS_TRACE_MTD,
+	  (TSTR("packed tags obj %d chunk %d byte %d seq %d" TENDSTR),
+	   ptt->obj_id, ptt->chunk_id, ptt->n_bytes,
+	   ptt->seq_number));
+}
+static void yaffs_dump_packed_tags2(const yaffs_packed_tags2 *pt)
+{
+	yaffs_dump_packed_tags2_tags_only(&pt->t);
+}
+
+static void yaffs_dump_tags2(const yaffs_ext_tags *t)
+{
+	T(YAFFS_TRACE_MTD,
+	  (TSTR
+	   ("ext.tags eccres %d blkbad %d chused %d obj %d chunk%d byte %d del %d ser %d seq %d"
+	    TENDSTR), t->ecc_result, t->block_bad, t->chunk_used, t->obj_id,
+	   t->chunk_id, t->n_bytes, t->is_deleted, t->serial_number,
+	   t->seq_number));
+
+}
+
+void yaffs_pack_tags2_tags_only(yaffs_packed_tags2_tags_only *ptt,
+		const yaffs_ext_tags *t)
+{
+	ptt->chunk_id = t->chunk_id;
+	ptt->seq_number = t->seq_number;
+	ptt->n_bytes = t->n_bytes;
+	ptt->obj_id = t->obj_id;
+
+	if (t->chunk_id == 0 && t->extra_available) {
+		/* Store the extra header info instead */
+		/* We save the parent object in the chunk_id */
+		ptt->chunk_id = EXTRA_HEADER_INFO_FLAG
+			| t->extra_parent_id;
+		if (t->extra_is_shrink)
+			ptt->chunk_id |= EXTRA_SHRINK_FLAG;
+		if (t->extra_shadows)
+			ptt->chunk_id |= EXTRA_SHADOWS_FLAG;
+
+		ptt->obj_id &= ~EXTRA_OBJECT_TYPE_MASK;
+		ptt->obj_id |=
+		    (t->extra_obj_type << EXTRA_OBJECT_TYPE_SHIFT);
+
+		if (t->extra_obj_type == YAFFS_OBJECT_TYPE_HARDLINK)
+			ptt->n_bytes = t->extra_equiv_id;
+		else if (t->extra_obj_type == YAFFS_OBJECT_TYPE_FILE)
+			ptt->n_bytes = t->extra_length;
+		else
+			ptt->n_bytes = 0;
+	}
+
+	yaffs_dump_packed_tags2_tags_only(ptt);
+	yaffs_dump_tags2(t);
+}
+
+
+void yaffs_pack_tags2(yaffs_packed_tags2 *pt, const yaffs_ext_tags *t, int tags_ecc)
+{
+	yaffs_pack_tags2_tags_only(&pt->t, t);
+
+	if(tags_ecc)
+		yaffs_ecc_calc_other((unsigned char *)&pt->t,
+					sizeof(yaffs_packed_tags2_tags_only),
+					&pt->ecc);
+}
+
+
+void yaffs_unpack_tags2_tags_only(yaffs_ext_tags *t,
+		yaffs_packed_tags2_tags_only *ptt)
+{
+
+	memset(t, 0, sizeof(yaffs_ext_tags));
+
+	yaffs_init_tags(t);
+
+	if (ptt->seq_number != 0xFFFFFFFF) {
+		t->block_bad = 0;
+		t->chunk_used = 1;
+		t->obj_id = ptt->obj_id;
+		t->chunk_id = ptt->chunk_id;
+		t->n_bytes = ptt->n_bytes;
+		t->is_deleted = 0;
+		t->serial_number = 0;
+		t->seq_number = ptt->seq_number;
+
+		/* Do extra header info stuff */
+
+		if (ptt->chunk_id & EXTRA_HEADER_INFO_FLAG) {
+			t->chunk_id = 0;
+			t->n_bytes = 0;
+
+			t->extra_available = 1;
+			t->extra_parent_id =
+			    ptt->chunk_id & (~(ALL_EXTRA_FLAGS));
+			t->extra_is_shrink =
+			    (ptt->chunk_id & EXTRA_SHRINK_FLAG) ? 1 : 0;
+			t->extra_shadows =
+			    (ptt->chunk_id & EXTRA_SHADOWS_FLAG) ? 1 : 0;
+			t->extra_obj_type =
+			    ptt->obj_id >> EXTRA_OBJECT_TYPE_SHIFT;
+			t->obj_id &= ~EXTRA_OBJECT_TYPE_MASK;
+
+			if (t->extra_obj_type == YAFFS_OBJECT_TYPE_HARDLINK)
+				t->extra_equiv_id = ptt->n_bytes;
+			else
+				t->extra_length = ptt->n_bytes;
+		}
+	}
+
+	yaffs_dump_packed_tags2_tags_only(ptt);
+	yaffs_dump_tags2(t);
+
+}
+
+
+void yaffs_unpack_tags2(yaffs_ext_tags *t, yaffs_packed_tags2 *pt, int tags_ecc)
+{
+
+	yaffs_ecc_result ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
+
+	if (pt->t.seq_number != 0xFFFFFFFF &&
+	    tags_ecc){
+		/* Chunk is in use and we need to do ECC */
+		
+		yaffs_ecc_other ecc;
+		int result;
+		yaffs_ecc_calc_other((unsigned char *)&pt->t,
+					sizeof(yaffs_packed_tags2_tags_only),
+					&ecc);
+		result = yaffs_ecc_correct_other((unsigned char *)&pt->t,
+						sizeof(yaffs_packed_tags2_tags_only),
+						&pt->ecc, &ecc);
+		switch (result) {
+			case 0:
+				ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
+				break;
+			case 1:
+				ecc_result = YAFFS_ECC_RESULT_FIXED;
+				break;
+			case -1:
+				ecc_result = YAFFS_ECC_RESULT_UNFIXED;
+				break;
+			default:
+				ecc_result = YAFFS_ECC_RESULT_UNKNOWN;
+		}
+	}
+
+	yaffs_unpack_tags2_tags_only(t, &pt->t);
+
+	t->ecc_result = ecc_result;
+
+	yaffs_dump_packed_tags2(pt);
+	yaffs_dump_tags2(t);
+}
+
diff --git a/drivers/staging/yaffs2/yaffs_packedtags2.h b/drivers/staging/yaffs2/yaffs_packedtags2.h
new file mode 100644
index 0000000..fd7a239
--- /dev/null
+++ b/drivers/staging/yaffs2/yaffs_packedtags2.h
@@ -0,0 +1,43 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+/* This is used to pack YAFFS2 tags, not YAFFS1tags. */
+
+#ifndef __YAFFS_PACKEDTAGS2_H__
+#define __YAFFS_PACKEDTAGS2_H__
+
+#include "yaffs_guts.h"
+#include "yaffs_ecc.h"
+
+typedef struct {
+	unsigned seq_number;
+	unsigned obj_id;
+	unsigned chunk_id;
+	unsigned n_bytes;
+} yaffs_packed_tags2_tags_only;
+
+typedef struct {
+	yaffs_packed_tags2_tags_only t;
+	yaffs_ecc_other ecc;
+} yaffs_packed_tags2;
+
+/* Full packed tags with ECC, used for oob tags */
+void yaffs_pack_tags2(yaffs_packed_tags2 *pt, const yaffs_ext_tags *t, int tags_ecc);
+void yaffs_unpack_tags2(yaffs_ext_tags *t, yaffs_packed_tags2 *pt, int tags_ecc);
+
+/* Only the tags part (no ECC for use with inband tags */
+void yaffs_pack_tags2_tags_only(yaffs_packed_tags2_tags_only *pt, const yaffs_ext_tags *t);
+void yaffs_unpack_tags2_tags_only(yaffs_ext_tags *t, yaffs_packed_tags2_tags_only *pt);
+#endif
-- 
1.7.3.2.146.gca209