[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/fs/jffs2/compr_rubin.c b/src/kernel/linux/v4.14/fs/jffs2/compr_rubin.c
new file mode 100644
index 0000000..556de10
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/jffs2/compr_rubin.c
@@ -0,0 +1,452 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright © 2001-2007 Red Hat, Inc.
+ * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
+ *
+ * Created by Arjan van de Ven <arjanv@redhat.com>
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/jffs2.h>
+#include <linux/errno.h>
+#include "compr.h"
+
+
+#define RUBIN_REG_SIZE 16
+#define UPPER_BIT_RUBIN (((long) 1)<<(RUBIN_REG_SIZE-1))
+#define LOWER_BITS_RUBIN ((((long) 1)<<(RUBIN_REG_SIZE-1))-1)
+
+
+#define BIT_DIVIDER_MIPS 1043
+static int bits_mips[8] = { 277, 249, 290, 267, 229, 341, 212, 241};
+
+struct pushpull {
+ unsigned char *buf;
+ unsigned int buflen;
+ unsigned int ofs;
+ unsigned int reserve;
+};
+
+struct rubin_state {
+ unsigned long p;
+ unsigned long q;
+ unsigned long rec_q;
+ long bit_number;
+ struct pushpull pp;
+ int bit_divider;
+ int bits[8];
+};
+
+static inline void init_pushpull(struct pushpull *pp, char *buf,
+ unsigned buflen, unsigned ofs,
+ unsigned reserve)
+{
+ pp->buf = buf;
+ pp->buflen = buflen;
+ pp->ofs = ofs;
+ pp->reserve = reserve;
+}
+
+static inline int pushbit(struct pushpull *pp, int bit, int use_reserved)
+{
+ if (pp->ofs >= pp->buflen - (use_reserved?0:pp->reserve))
+ return -ENOSPC;
+
+ if (bit)
+ pp->buf[pp->ofs >> 3] |= (1<<(7-(pp->ofs & 7)));
+ else
+ pp->buf[pp->ofs >> 3] &= ~(1<<(7-(pp->ofs & 7)));
+
+ pp->ofs++;
+
+ return 0;
+}
+
+static inline int pushedbits(struct pushpull *pp)
+{
+ return pp->ofs;
+}
+
+static inline int pullbit(struct pushpull *pp)
+{
+ int bit;
+
+ bit = (pp->buf[pp->ofs >> 3] >> (7-(pp->ofs & 7))) & 1;
+
+ pp->ofs++;
+ return bit;
+}
+
+
+static void init_rubin(struct rubin_state *rs, int div, int *bits)
+{
+ int c;
+
+ rs->q = 0;
+ rs->p = (long) (2 * UPPER_BIT_RUBIN);
+ rs->bit_number = (long) 0;
+ rs->bit_divider = div;
+
+ for (c=0; c<8; c++)
+ rs->bits[c] = bits[c];
+}
+
+
+static int encode(struct rubin_state *rs, long A, long B, int symbol)
+{
+
+ long i0, i1;
+ int ret;
+
+ while ((rs->q >= UPPER_BIT_RUBIN) ||
+ ((rs->p + rs->q) <= UPPER_BIT_RUBIN)) {
+ rs->bit_number++;
+
+ ret = pushbit(&rs->pp, (rs->q & UPPER_BIT_RUBIN) ? 1 : 0, 0);
+ if (ret)
+ return ret;
+ rs->q &= LOWER_BITS_RUBIN;
+ rs->q <<= 1;
+ rs->p <<= 1;
+ }
+ i0 = A * rs->p / (A + B);
+ if (i0 <= 0)
+ i0 = 1;
+
+ if (i0 >= rs->p)
+ i0 = rs->p - 1;
+
+ i1 = rs->p - i0;
+
+ if (symbol == 0)
+ rs->p = i0;
+ else {
+ rs->p = i1;
+ rs->q += i0;
+ }
+ return 0;
+}
+
+
+static void end_rubin(struct rubin_state *rs)
+{
+
+ int i;
+
+ for (i = 0; i < RUBIN_REG_SIZE; i++) {
+ pushbit(&rs->pp, (UPPER_BIT_RUBIN & rs->q) ? 1 : 0, 1);
+ rs->q &= LOWER_BITS_RUBIN;
+ rs->q <<= 1;
+ }
+}
+
+
+static void init_decode(struct rubin_state *rs, int div, int *bits)
+{
+ init_rubin(rs, div, bits);
+
+ /* behalve lower */
+ rs->rec_q = 0;
+
+ for (rs->bit_number = 0; rs->bit_number++ < RUBIN_REG_SIZE;
+ rs->rec_q = rs->rec_q * 2 + (long) (pullbit(&rs->pp)))
+ ;
+}
+
+static void __do_decode(struct rubin_state *rs, unsigned long p,
+ unsigned long q)
+{
+ register unsigned long lower_bits_rubin = LOWER_BITS_RUBIN;
+ unsigned long rec_q;
+ int c, bits = 0;
+
+ /*
+ * First, work out how many bits we need from the input stream.
+ * Note that we have already done the initial check on this
+ * loop prior to calling this function.
+ */
+ do {
+ bits++;
+ q &= lower_bits_rubin;
+ q <<= 1;
+ p <<= 1;
+ } while ((q >= UPPER_BIT_RUBIN) || ((p + q) <= UPPER_BIT_RUBIN));
+
+ rs->p = p;
+ rs->q = q;
+
+ rs->bit_number += bits;
+
+ /*
+ * Now get the bits. We really want this to be "get n bits".
+ */
+ rec_q = rs->rec_q;
+ do {
+ c = pullbit(&rs->pp);
+ rec_q &= lower_bits_rubin;
+ rec_q <<= 1;
+ rec_q += c;
+ } while (--bits);
+ rs->rec_q = rec_q;
+}
+
+static int decode(struct rubin_state *rs, long A, long B)
+{
+ unsigned long p = rs->p, q = rs->q;
+ long i0, threshold;
+ int symbol;
+
+ if (q >= UPPER_BIT_RUBIN || ((p + q) <= UPPER_BIT_RUBIN))
+ __do_decode(rs, p, q);
+
+ i0 = A * rs->p / (A + B);
+ if (i0 <= 0)
+ i0 = 1;
+
+ if (i0 >= rs->p)
+ i0 = rs->p - 1;
+
+ threshold = rs->q + i0;
+ symbol = rs->rec_q >= threshold;
+ if (rs->rec_q >= threshold) {
+ rs->q += i0;
+ i0 = rs->p - i0;
+ }
+
+ rs->p = i0;
+
+ return symbol;
+}
+
+
+
+static int out_byte(struct rubin_state *rs, unsigned char byte)
+{
+ int i, ret;
+ struct rubin_state rs_copy;
+ rs_copy = *rs;
+
+ for (i=0; i<8; i++) {
+ ret = encode(rs, rs->bit_divider-rs->bits[i],
+ rs->bits[i], byte & 1);
+ if (ret) {
+ /* Failed. Restore old state */
+ *rs = rs_copy;
+ return ret;
+ }
+ byte >>= 1 ;
+ }
+ return 0;
+}
+
+static int in_byte(struct rubin_state *rs)
+{
+ int i, result = 0, bit_divider = rs->bit_divider;
+
+ for (i = 0; i < 8; i++)
+ result |= decode(rs, bit_divider - rs->bits[i],
+ rs->bits[i]) << i;
+
+ return result;
+}
+
+
+
+static int rubin_do_compress(int bit_divider, int *bits, unsigned char *data_in,
+ unsigned char *cpage_out, uint32_t *sourcelen,
+ uint32_t *dstlen)
+ {
+ int outpos = 0;
+ int pos=0;
+ struct rubin_state rs;
+
+ init_pushpull(&rs.pp, cpage_out, *dstlen * 8, 0, 32);
+
+ init_rubin(&rs, bit_divider, bits);
+
+ while (pos < (*sourcelen) && !out_byte(&rs, data_in[pos]))
+ pos++;
+
+ end_rubin(&rs);
+
+ if (outpos > pos) {
+ /* We failed */
+ return -1;
+ }
+
+ /* Tell the caller how much we managed to compress,
+ * and how much space it took */
+
+ outpos = (pushedbits(&rs.pp)+7)/8;
+
+ if (outpos >= pos)
+ return -1; /* We didn't actually compress */
+ *sourcelen = pos;
+ *dstlen = outpos;
+ return 0;
+}
+#if 0
+/* _compress returns the compressed size, -1 if bigger */
+int jffs2_rubinmips_compress(unsigned char *data_in, unsigned char *cpage_out,
+ uint32_t *sourcelen, uint32_t *dstlen)
+{
+ return rubin_do_compress(BIT_DIVIDER_MIPS, bits_mips, data_in,
+ cpage_out, sourcelen, dstlen);
+}
+#endif
+static int jffs2_dynrubin_compress(unsigned char *data_in,
+ unsigned char *cpage_out,
+ uint32_t *sourcelen, uint32_t *dstlen)
+{
+ int bits[8];
+ unsigned char histo[256];
+ int i;
+ int ret;
+ uint32_t mysrclen, mydstlen;
+
+ mysrclen = *sourcelen;
+ mydstlen = *dstlen - 8;
+
+ if (*dstlen <= 12)
+ return -1;
+
+ memset(histo, 0, 256);
+ for (i=0; i<mysrclen; i++)
+ histo[data_in[i]]++;
+ memset(bits, 0, sizeof(int)*8);
+ for (i=0; i<256; i++) {
+ if (i&128)
+ bits[7] += histo[i];
+ if (i&64)
+ bits[6] += histo[i];
+ if (i&32)
+ bits[5] += histo[i];
+ if (i&16)
+ bits[4] += histo[i];
+ if (i&8)
+ bits[3] += histo[i];
+ if (i&4)
+ bits[2] += histo[i];
+ if (i&2)
+ bits[1] += histo[i];
+ if (i&1)
+ bits[0] += histo[i];
+ }
+
+ for (i=0; i<8; i++) {
+ bits[i] = (bits[i] * 256) / mysrclen;
+ if (!bits[i]) bits[i] = 1;
+ if (bits[i] > 255) bits[i] = 255;
+ cpage_out[i] = bits[i];
+ }
+
+ ret = rubin_do_compress(256, bits, data_in, cpage_out+8, &mysrclen,
+ &mydstlen);
+ if (ret)
+ return ret;
+
+ /* Add back the 8 bytes we took for the probabilities */
+ mydstlen += 8;
+
+ if (mysrclen <= mydstlen) {
+ /* We compressed */
+ return -1;
+ }
+
+ *sourcelen = mysrclen;
+ *dstlen = mydstlen;
+ return 0;
+}
+
+static void rubin_do_decompress(int bit_divider, int *bits,
+ unsigned char *cdata_in,
+ unsigned char *page_out, uint32_t srclen,
+ uint32_t destlen)
+{
+ int outpos = 0;
+ struct rubin_state rs;
+
+ init_pushpull(&rs.pp, cdata_in, srclen, 0, 0);
+ init_decode(&rs, bit_divider, bits);
+
+ while (outpos < destlen)
+ page_out[outpos++] = in_byte(&rs);
+}
+
+
+static int jffs2_rubinmips_decompress(unsigned char *data_in,
+ unsigned char *cpage_out,
+ uint32_t sourcelen, uint32_t dstlen)
+{
+ rubin_do_decompress(BIT_DIVIDER_MIPS, bits_mips, data_in,
+ cpage_out, sourcelen, dstlen);
+ return 0;
+}
+
+static int jffs2_dynrubin_decompress(unsigned char *data_in,
+ unsigned char *cpage_out,
+ uint32_t sourcelen, uint32_t dstlen)
+{
+ int bits[8];
+ int c;
+
+ for (c=0; c<8; c++)
+ bits[c] = data_in[c];
+
+ rubin_do_decompress(256, bits, data_in+8, cpage_out, sourcelen-8,
+ dstlen);
+ return 0;
+}
+
+static struct jffs2_compressor jffs2_rubinmips_comp = {
+ .priority = JFFS2_RUBINMIPS_PRIORITY,
+ .name = "rubinmips",
+ .compr = JFFS2_COMPR_DYNRUBIN,
+ .compress = NULL, /*&jffs2_rubinmips_compress,*/
+ .decompress = &jffs2_rubinmips_decompress,
+#ifdef JFFS2_RUBINMIPS_DISABLED
+ .disabled = 1,
+#else
+ .disabled = 0,
+#endif
+};
+
+int jffs2_rubinmips_init(void)
+{
+ return jffs2_register_compressor(&jffs2_rubinmips_comp);
+}
+
+void jffs2_rubinmips_exit(void)
+{
+ jffs2_unregister_compressor(&jffs2_rubinmips_comp);
+}
+
+static struct jffs2_compressor jffs2_dynrubin_comp = {
+ .priority = JFFS2_DYNRUBIN_PRIORITY,
+ .name = "dynrubin",
+ .compr = JFFS2_COMPR_RUBINMIPS,
+ .compress = jffs2_dynrubin_compress,
+ .decompress = &jffs2_dynrubin_decompress,
+#ifdef JFFS2_DYNRUBIN_DISABLED
+ .disabled = 1,
+#else
+ .disabled = 0,
+#endif
+};
+
+int jffs2_dynrubin_init(void)
+{
+ return jffs2_register_compressor(&jffs2_dynrubin_comp);
+}
+
+void jffs2_dynrubin_exit(void)
+{
+ jffs2_unregister_compressor(&jffs2_dynrubin_comp);
+}