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authorLinus Torvalds <torvalds@linux-foundation.org>2018-06-05 10:48:05 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-06-05 10:48:05 -0700
commit25d80be86c5d7f53df41ec5ce96f6c6543cac245 (patch)
treea18fe8d5281d0ed44c049d5a59da499278bb6e3e /include
parenta74e0c4c9cb02d44bc5ec1a70a6ba599366fb130 (diff)
parent45888b40d2a6221d46bb69959e2600ddba71cc1f (diff)
downloadlinux-25d80be86c5d7f53df41ec5ce96f6c6543cac245.tar.bz2
Merge tag 'rslib-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull reed-salomon library updates from Kees Cook: "Refactors rslib and callers to provide a per-instance allocation area instead of performing VLAs on the stack" * tag 'rslib-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: rslib: Allocate decoder buffers to avoid VLAs mtd: rawnand: diskonchip: Allocate rs control per instance rslib: Split rs control struct rslib: Simplify error path rslib: Remove GPL boilerplate rslib: Add SPDX identifiers rslib: Cleanup top level comments rslib: Cleanup whitespace damage dm/verity_fec: Use GFP aware reed solomon init rslib: Add GFP aware init function
Diffstat (limited to 'include')
-rw-r--r--include/linux/rslib.h74
1 files changed, 48 insertions, 26 deletions
diff --git a/include/linux/rslib.h b/include/linux/rslib.h
index 746580c1939c..5974cedd008c 100644
--- a/include/linux/rslib.h
+++ b/include/linux/rslib.h
@@ -1,28 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
/*
- * include/linux/rslib.h
- *
- * Overview:
- * Generic Reed Solomon encoder / decoder library
+ * Generic Reed Solomon encoder / decoder library
*
* Copyright (C) 2004 Thomas Gleixner (tglx@linutronix.de)
*
* RS code lifted from reed solomon library written by Phil Karn
* Copyright 2002 Phil Karn, KA9Q
- *
- * $Id: rslib.h,v 1.4 2005/11/07 11:14:52 gleixner Exp $
- *
- * 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.
*/
-
#ifndef _RSLIB_H_
#define _RSLIB_H_
#include <linux/list.h>
+#include <linux/types.h> /* for gfp_t */
+#include <linux/gfp.h> /* for GFP_KERNEL */
/**
- * struct rs_control - rs control structure
+ * struct rs_codec - rs codec data
*
* @mm: Bits per symbol
* @nn: Symbols per block (= (1<<mm)-1)
@@ -36,24 +29,34 @@
* @gfpoly: The primitive generator polynominal
* @gffunc: Function to generate the field, if non-canonical representation
* @users: Users of this structure
- * @list: List entry for the rs control list
+ * @list: List entry for the rs codec list
*/
-struct rs_control {
- int mm;
- int nn;
+struct rs_codec {
+ int mm;
+ int nn;
uint16_t *alpha_to;
uint16_t *index_of;
uint16_t *genpoly;
- int nroots;
- int fcr;
- int prim;
- int iprim;
+ int nroots;
+ int fcr;
+ int prim;
+ int iprim;
int gfpoly;
int (*gffunc)(int);
int users;
struct list_head list;
};
+/**
+ * struct rs_control - rs control structure per instance
+ * @codec: The codec used for this instance
+ * @buffers: Internal scratch buffers used in calls to decode_rs()
+ */
+struct rs_control {
+ struct rs_codec *codec;
+ uint16_t buffers[0];
+};
+
/* General purpose RS codec, 8-bit data width, symbol width 1-15 bit */
#ifdef CONFIG_REED_SOLOMON_ENC8
int encode_rs8(struct rs_control *rs, uint8_t *data, int len, uint16_t *par,
@@ -76,18 +79,37 @@ int decode_rs16(struct rs_control *rs, uint16_t *data, uint16_t *par, int len,
uint16_t *corr);
#endif
-/* Create or get a matching rs control structure */
-struct rs_control *init_rs(int symsize, int gfpoly, int fcr, int prim,
- int nroots);
+struct rs_control *init_rs_gfp(int symsize, int gfpoly, int fcr, int prim,
+ int nroots, gfp_t gfp);
+
+/**
+ * init_rs - Create a RS control struct and initialize it
+ * @symsize: the symbol size (number of bits)
+ * @gfpoly: the extended Galois field generator polynomial coefficients,
+ * with the 0th coefficient in the low order bit. The polynomial
+ * must be primitive;
+ * @fcr: the first consecutive root of the rs code generator polynomial
+ * in index form
+ * @prim: primitive element to generate polynomial roots
+ * @nroots: RS code generator polynomial degree (number of roots)
+ *
+ * Allocations use GFP_KERNEL.
+ */
+static inline struct rs_control *init_rs(int symsize, int gfpoly, int fcr,
+ int prim, int nroots)
+{
+ return init_rs_gfp(symsize, gfpoly, fcr, prim, nroots, GFP_KERNEL);
+}
+
struct rs_control *init_rs_non_canonical(int symsize, int (*func)(int),
- int fcr, int prim, int nroots);
+ int fcr, int prim, int nroots);
/* Release a rs control structure */
void free_rs(struct rs_control *rs);
/** modulo replacement for galois field arithmetics
*
- * @rs: the rs control structure
+ * @rs: Pointer to the RS codec
* @x: the value to reduce
*
* where
@@ -97,7 +119,7 @@ void free_rs(struct rs_control *rs);
* Simple arithmetic modulo would return a wrong result for values
* >= 3 * rs->nn
*/
-static inline int rs_modnn(struct rs_control *rs, int x)
+static inline int rs_modnn(struct rs_codec *rs, int x)
{
while (x >= rs->nn) {
x -= rs->nn;