--- /dev/null
+/*
+ * Cryptographic API for the NX-842 hardware compression.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * Copyright (C) IBM Corporation, 2011-2015
+ *
+ * Original Authors: Robert Jennings <rcj@linux.vnet.ibm.com>
+ * Seth Jennings <sjenning@linux.vnet.ibm.com>
+ *
+ * Rewrite: Dan Streetman <ddstreet@ieee.org>
+ *
+ * This is an interface to the NX-842 compression hardware in PowerPC
+ * processors. Most of the complexity of this drvier is due to the fact that
+ * the NX-842 compression hardware requires the input and output data buffers
+ * to be specifically aligned, to be a specific multiple in length, and within
+ * specific minimum and maximum lengths. Those restrictions, provided by the
+ * nx-842 driver via nx842_constraints, mean this driver must use bounce
+ * buffers and headers to correct misaligned in or out buffers, and to split
+ * input buffers that are too large.
+ *
+ * This driver will fall back to software decompression if the hardware
+ * decompression fails, so this driver's decompression should never fail as
+ * long as the provided compressed buffer is valid. Any compressed buffer
+ * created by this driver will have a header (except ones where the input
+ * perfectly matches the constraints); so users of this driver cannot simply
+ * pass a compressed buffer created by this driver over to the 842 software
+ * decompression library. Instead, users must use this driver to decompress;
+ * if the hardware fails or is unavailable, the compressed buffer will be
+ * parsed and the header removed, and the raw 842 buffer(s) passed to the 842
+ * software decompression library.
+ *
+ * This does not fall back to software compression, however, since the caller
+ * of this function is specifically requesting hardware compression; if the
+ * hardware compression fails, the caller can fall back to software
+ * compression, and the raw 842 compressed buffer that the software compressor
+ * creates can be passed to this driver for hardware decompression; any
+ * buffer without our specific header magic is assumed to be a raw 842 buffer
+ * and passed directly to the hardware. Note that the software compression
+ * library will produce a compressed buffer that is incompatible with the
+ * hardware decompressor if the original input buffer length is not a multiple
+ * of 8; if such a compressed buffer is passed to this driver for
+ * decompression, the hardware will reject it and this driver will then pass
+ * it over to the software library for decompression.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/crypto.h>
+#include <linux/vmalloc.h>
+#include <linux/nx842.h>
+#include <linux/sw842.h>
+#include <linux/ratelimit.h>
+
+/* The first 5 bits of this magic are 0x1f, which is an invalid 842 5-bit
+ * template (see lib/842/842.h), so this magic number will never appear at
+ * the start of a raw 842 compressed buffer. That is important, as any buffer
+ * passed to us without this magic is assumed to be a raw 842 compressed
+ * buffer, and passed directly to the hardware to decompress.
+ */
+#define NX842_CRYPTO_MAGIC (0xf842)
+#define NX842_CRYPTO_GROUP_MAX (0x20)
+#define NX842_CRYPTO_HEADER_SIZE(g) \
+ (sizeof(struct nx842_crypto_header) + \
+ sizeof(struct nx842_crypto_header_group) * (g))
+#define NX842_CRYPTO_HEADER_MAX_SIZE \
+ NX842_CRYPTO_HEADER_SIZE(NX842_CRYPTO_GROUP_MAX)
+
+/* bounce buffer size */
+#define BOUNCE_BUFFER_ORDER (2)
+#define BOUNCE_BUFFER_SIZE \
+ ((unsigned int)(PAGE_SIZE << BOUNCE_BUFFER_ORDER))
+
+/* try longer on comp because we can fallback to sw decomp if hw is busy */
+#define COMP_BUSY_TIMEOUT (250) /* ms */
+#define DECOMP_BUSY_TIMEOUT (50) /* ms */
+
+struct nx842_crypto_header_group {
+ __be16 padding; /* unused bytes at start of group */
+ __be32 compressed_length; /* compressed bytes in group */
+ __be32 uncompressed_length; /* bytes after decompression */
+} __packed;
+
+struct nx842_crypto_header {
+ __be16 magic; /* NX842_CRYPTO_MAGIC */
+ __be16 ignore; /* decompressed end bytes to ignore */
+ u8 groups; /* total groups in this header */
+ struct nx842_crypto_header_group group[];
+} __packed;
+
+struct nx842_crypto_param {
+ u8 *in;
+ unsigned int iremain;
+ u8 *out;
+ unsigned int oremain;
+ unsigned int ototal;
+};
+
+static int update_param(struct nx842_crypto_param *p,
+ unsigned int slen, unsigned int dlen)
+{
+ if (p->iremain < slen)
+ return -EOVERFLOW;
+ if (p->oremain < dlen)
+ return -ENOSPC;
+
+ p->in += slen;
+ p->iremain -= slen;
+ p->out += dlen;
+ p->oremain -= dlen;
+ p->ototal += dlen;
+
+ return 0;
+}
+
+struct nx842_crypto_ctx {
+ u8 *wmem;
+ u8 *sbounce, *dbounce;
+
+ struct nx842_crypto_header header;
+ struct nx842_crypto_header_group group[NX842_CRYPTO_GROUP_MAX];
+};
+
+static int nx842_crypto_init(struct crypto_tfm *tfm)
+{
+ struct nx842_crypto_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ ctx->wmem = kmalloc(NX842_MEM_COMPRESS, GFP_KERNEL);
+ ctx->sbounce = (u8 *)__get_free_pages(GFP_KERNEL, BOUNCE_BUFFER_ORDER);
+ ctx->dbounce = (u8 *)__get_free_pages(GFP_KERNEL, BOUNCE_BUFFER_ORDER);
+ if (!ctx->wmem || !ctx->sbounce || !ctx->dbounce) {
+ kfree(ctx->wmem);
+ free_page((unsigned long)ctx->sbounce);
+ free_page((unsigned long)ctx->dbounce);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static void nx842_crypto_exit(struct crypto_tfm *tfm)
+{
+ struct nx842_crypto_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ kfree(ctx->wmem);
+ free_page((unsigned long)ctx->sbounce);
+ free_page((unsigned long)ctx->dbounce);
+}
+
+static int read_constraints(struct nx842_constraints *c)
+{
+ int ret;
+
+ ret = nx842_constraints(c);
+ if (ret) {
+ pr_err_ratelimited("could not get nx842 constraints : %d\n",
+ ret);
+ return ret;
+ }
+
+ /* limit maximum, to always have enough bounce buffer to decompress */
+ if (c->maximum > BOUNCE_BUFFER_SIZE) {
+ c->maximum = BOUNCE_BUFFER_SIZE;
+ pr_info_once("limiting nx842 maximum to %x\n", c->maximum);
+ }
+
+ return 0;
+}
+
+static int nx842_crypto_add_header(struct nx842_crypto_header *hdr, u8 *buf)
+{
+ int s = NX842_CRYPTO_HEADER_SIZE(hdr->groups);
+
+ /* compress should have added space for header */
+ if (s > be16_to_cpu(hdr->group[0].padding)) {
+ pr_err("Internal error: no space for header\n");
+ return -EINVAL;
+ }
+
+ memcpy(buf, hdr, s);
+
+ print_hex_dump_debug("header ", DUMP_PREFIX_OFFSET, 16, 1, buf, s, 0);
+
+ return 0;
+}
+
+static int compress(struct nx842_crypto_ctx *ctx,
+ struct nx842_crypto_param *p,
+ struct nx842_crypto_header_group *g,
+ struct nx842_constraints *c,
+ u16 *ignore,
+ unsigned int hdrsize)
+{
+ unsigned int slen = p->iremain, dlen = p->oremain, tmplen;
+ unsigned int adj_slen = slen;
+ u8 *src = p->in, *dst = p->out;
+ int ret, dskip = 0;
+ ktime_t timeout;
+
+ if (p->iremain == 0)
+ return -EOVERFLOW;
+
+ if (p->oremain == 0 || hdrsize + c->minimum > dlen)
+ return -ENOSPC;
+
+ if (slen % c->multiple)
+ adj_slen = round_up(slen, c->multiple);
+ if (slen < c->minimum)
+ adj_slen = c->minimum;
+ if (slen > c->maximum)
+ adj_slen = slen = c->maximum;
+ if (adj_slen > slen || (u64)src % c->alignment) {
+ adj_slen = min(adj_slen, BOUNCE_BUFFER_SIZE);
+ slen = min(slen, BOUNCE_BUFFER_SIZE);
+ if (adj_slen > slen)
+ memset(ctx->sbounce + slen, 0, adj_slen - slen);
+ memcpy(ctx->sbounce, src, slen);
+ src = ctx->sbounce;
+ slen = adj_slen;
+ pr_debug("using comp sbounce buffer, len %x\n", slen);
+ }
+
+ dst += hdrsize;
+ dlen -= hdrsize;
+
+ if ((u64)dst % c->alignment) {
+ dskip = (int)(PTR_ALIGN(dst, c->alignment) - dst);
+ dst += dskip;
+ dlen -= dskip;
+ }
+ if (dlen % c->multiple)
+ dlen = round_down(dlen, c->multiple);
+ if (dlen < c->minimum) {
+nospc:
+ dst = ctx->dbounce;
+ dlen = min(p->oremain, BOUNCE_BUFFER_SIZE);
+ dlen = round_down(dlen, c->multiple);
+ dskip = 0;
+ pr_debug("using comp dbounce buffer, len %x\n", dlen);
+ }
+ if (dlen > c->maximum)
+ dlen = c->maximum;
+
+ tmplen = dlen;
+ timeout = ktime_add_ms(ktime_get(), COMP_BUSY_TIMEOUT);
+ do {
+ dlen = tmplen; /* reset dlen, if we're retrying */
+ ret = nx842_compress(src, slen, dst, &dlen, ctx->wmem);
+ /* possibly we should reduce the slen here, instead of
+ * retrying with the dbounce buffer?
+ */
+ if (ret == -ENOSPC && dst != ctx->dbounce)
+ goto nospc;
+ } while (ret == -EBUSY && ktime_before(ktime_get(), timeout));
+ if (ret)
+ return ret;
+
+ dskip += hdrsize;
+
+ if (dst == ctx->dbounce)
+ memcpy(p->out + dskip, dst, dlen);
+
+ g->padding = cpu_to_be16(dskip);
+ g->compressed_length = cpu_to_be32(dlen);
+ g->uncompressed_length = cpu_to_be32(slen);
+
+ if (p->iremain < slen) {
+ *ignore = slen - p->iremain;
+ slen = p->iremain;
+ }
+
+ pr_debug("compress slen %x ignore %x dlen %x padding %x\n",
+ slen, *ignore, dlen, dskip);
+
+ return update_param(p, slen, dskip + dlen);
+}
+
+static int nx842_crypto_compress(struct crypto_tfm *tfm,
+ const u8 *src, unsigned int slen,
+ u8 *dst, unsigned int *dlen)
+{
+ struct nx842_crypto_ctx *ctx = crypto_tfm_ctx(tfm);
+ struct nx842_crypto_header *hdr = &ctx->header;
+ struct nx842_crypto_param p;
+ struct nx842_constraints c;
+ unsigned int groups, hdrsize, h;
+ int ret, n;
+ bool add_header;
+ u16 ignore = 0;
+
+ if (!tfm || !src || !slen || !dst || !dlen)
+ return -EINVAL;
+
+ p.in = (u8 *)src;
+ p.iremain = slen;
+ p.out = dst;
+ p.oremain = *dlen;
+ p.ototal = 0;
+
+ *dlen = 0;
+
+ ret = read_constraints(&c);
+ if (ret)
+ return ret;
+
+ groups = min_t(unsigned int, NX842_CRYPTO_GROUP_MAX,
+ DIV_ROUND_UP(p.iremain, c.maximum));
+ hdrsize = NX842_CRYPTO_HEADER_SIZE(groups);
+
+ /* skip adding header if the buffers meet all constraints */
+ add_header = (p.iremain % c.multiple ||
+ p.iremain < c.minimum ||
+ p.iremain > c.maximum ||
+ (u64)p.in % c.alignment ||
+ p.oremain % c.multiple ||
+ p.oremain < c.minimum ||
+ p.oremain > c.maximum ||
+ (u64)p.out % c.alignment);
+
+ hdr->magic = cpu_to_be16(NX842_CRYPTO_MAGIC);
+ hdr->groups = 0;
+ hdr->ignore = 0;
+
+ while (p.iremain > 0) {
+ n = hdr->groups++;
+ if (hdr->groups > NX842_CRYPTO_GROUP_MAX)
+ return -ENOSPC;
+
+ /* header goes before first group */
+ h = !n && add_header ? hdrsize : 0;
+
+ if (ignore)
+ pr_warn("interal error, ignore is set %x\n", ignore);
+
+ ret = compress(ctx, &p, &hdr->group[n], &c, &ignore, h);
+ if (ret)
+ return ret;
+ }
+
+ if (!add_header && hdr->groups > 1) {
+ pr_err("Internal error: No header but multiple groups\n");
+ return -EINVAL;
+ }
+
+ /* ignore indicates the input stream needed to be padded */
+ hdr->ignore = cpu_to_be16(ignore);
+ if (ignore)
+ pr_debug("marked %d bytes as ignore\n", ignore);
+
+ if (add_header)
+ ret = nx842_crypto_add_header(hdr, dst);
+ if (ret)
+ return ret;
+
+ *dlen = p.ototal;
+
+ pr_debug("compress total slen %x dlen %x\n", slen, *dlen);
+
+ return 0;
+}
+
+static int decompress(struct nx842_crypto_ctx *ctx,
+ struct nx842_crypto_param *p,
+ struct nx842_crypto_header_group *g,
+ struct nx842_constraints *c,
+ u16 ignore,
+ bool usehw)
+{
+ unsigned int slen = be32_to_cpu(g->compressed_length);
+ unsigned int required_len = be32_to_cpu(g->uncompressed_length);
+ unsigned int dlen = p->oremain, tmplen;
+ unsigned int adj_slen = slen;
+ u8 *src = p->in, *dst = p->out;
+ u16 padding = be16_to_cpu(g->padding);
+ int ret, spadding = 0, dpadding = 0;
+ ktime_t timeout;
+
+ if (!slen || !required_len)
+ return -EINVAL;
+
+ if (p->iremain <= 0 || padding + slen > p->iremain)
+ return -EOVERFLOW;
+
+ if (p->oremain <= 0 || required_len - ignore > p->oremain)
+ return -ENOSPC;
+
+ src += padding;
+
+ if (!usehw)
+ goto usesw;
+
+ if (slen % c->multiple)
+ adj_slen = round_up(slen, c->multiple);
+ if (slen < c->minimum)
+ adj_slen = c->minimum;
+ if (slen > c->maximum)
+ goto usesw;
+ if (slen < adj_slen || (u64)src % c->alignment) {
+ /* we can append padding bytes because the 842 format defines
+ * an "end" template (see lib/842/842_decompress.c) and will
+ * ignore any bytes following it.
+ */
+ if (slen < adj_slen)
+ memset(ctx->sbounce + slen, 0, adj_slen - slen);
+ memcpy(ctx->sbounce, src, slen);
+ src = ctx->sbounce;
+ spadding = adj_slen - slen;
+ slen = adj_slen;
+ pr_debug("using decomp sbounce buffer, len %x\n", slen);
+ }
+
+ if (dlen % c->multiple)
+ dlen = round_down(dlen, c->multiple);
+ if (dlen < required_len || (u64)dst % c->alignment) {
+ dst = ctx->dbounce;
+ dlen = min(required_len, BOUNCE_BUFFER_SIZE);
+ pr_debug("using decomp dbounce buffer, len %x\n", dlen);
+ }
+ if (dlen < c->minimum)
+ goto usesw;
+ if (dlen > c->maximum)
+ dlen = c->maximum;
+
+ tmplen = dlen;
+ timeout = ktime_add_ms(ktime_get(), DECOMP_BUSY_TIMEOUT);
+ do {
+ dlen = tmplen; /* reset dlen, if we're retrying */
+ ret = nx842_decompress(src, slen, dst, &dlen, ctx->wmem);
+ } while (ret == -EBUSY && ktime_before(ktime_get(), timeout));
+ if (ret) {
+usesw:
+ /* reset everything, sw doesn't have constraints */
+ src = p->in + padding;
+ slen = be32_to_cpu(g->compressed_length);
+ spadding = 0;
+ dst = p->out;
+ dlen = p->oremain;
+ dpadding = 0;
+ if (dlen < required_len) { /* have ignore bytes */
+ dst = ctx->dbounce;
+ dlen = BOUNCE_BUFFER_SIZE;
+ }
+ pr_info_ratelimited("using software 842 decompression\n");
+ ret = sw842_decompress(src, slen, dst, &dlen);
+ }
+ if (ret)
+ return ret;
+
+ slen -= spadding;
+
+ dlen -= ignore;
+ if (ignore)
+ pr_debug("ignoring last %x bytes\n", ignore);
+
+ if (dst == ctx->dbounce)
+ memcpy(p->out, dst, dlen);
+
+ pr_debug("decompress slen %x padding %x dlen %x ignore %x\n",
+ slen, padding, dlen, ignore);
+
+ return update_param(p, slen + padding, dlen);
+}
+
+static int nx842_crypto_decompress(struct crypto_tfm *tfm,
+ const u8 *src, unsigned int slen,
+ u8 *dst, unsigned int *dlen)
+{
+ struct nx842_crypto_ctx *ctx = crypto_tfm_ctx(tfm);
+ struct nx842_crypto_header *hdr;
+ struct nx842_crypto_param p;
+ struct nx842_constraints c;
+ int n, ret, hdr_len;
+ u16 ignore = 0;
+ bool usehw = true;
+
+ if (!tfm || !src || !slen || !dst || !dlen)
+ return -EINVAL;
+
+ p.in = (u8 *)src;
+ p.iremain = slen;
+ p.out = dst;
+ p.oremain = *dlen;
+ p.ototal = 0;
+
+ *dlen = 0;
+
+ if (read_constraints(&c))
+ usehw = false;
+
+ hdr = (struct nx842_crypto_header *)src;
+
+ /* If it doesn't start with our header magic number, assume it's a raw
+ * 842 compressed buffer and pass it directly to the hardware driver
+ */
+ if (be16_to_cpu(hdr->magic) != NX842_CRYPTO_MAGIC) {
+ struct nx842_crypto_header_group g = {
+ .padding = 0,
+ .compressed_length = cpu_to_be32(p.iremain),
+ .uncompressed_length = cpu_to_be32(p.oremain),
+ };
+
+ ret = decompress(ctx, &p, &g, &c, 0, usehw);
+ if (ret)
+ return ret;
+
+ *dlen = p.ototal;
+
+ return 0;
+ }
+
+ if (!hdr->groups) {
+ pr_err("header has no groups\n");
+ return -EINVAL;
+ }
+ if (hdr->groups > NX842_CRYPTO_GROUP_MAX) {
+ pr_err("header has too many groups %x, max %x\n",
+ hdr->groups, NX842_CRYPTO_GROUP_MAX);
+ return -EINVAL;
+ }
+
+ hdr_len = NX842_CRYPTO_HEADER_SIZE(hdr->groups);
+ if (hdr_len > slen)
+ return -EOVERFLOW;
+
+ memcpy(&ctx->header, src, hdr_len);
+ hdr = &ctx->header;
+
+ for (n = 0; n < hdr->groups; n++) {
+ /* ignore applies to last group */
+ if (n + 1 == hdr->groups)
+ ignore = be16_to_cpu(hdr->ignore);
+
+ ret = decompress(ctx, &p, &hdr->group[n], &c, ignore, usehw);
+ if (ret)
+ return ret;
+ }
+
+ *dlen = p.ototal;
+
+ pr_debug("decompress total slen %x dlen %x\n", slen, *dlen);
+
+ return 0;
+}
+
+static struct crypto_alg alg = {
+ .cra_name = "842",
+ .cra_driver_name = "842-nx",
+ .cra_priority = 300,
+ .cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
+ .cra_ctxsize = sizeof(struct nx842_crypto_ctx),
+ .cra_module = THIS_MODULE,
+ .cra_init = nx842_crypto_init,
+ .cra_exit = nx842_crypto_exit,
+ .cra_u = { .compress = {
+ .coa_compress = nx842_crypto_compress,
+ .coa_decompress = nx842_crypto_decompress } }
+};
+
+static int __init nx842_crypto_mod_init(void)
+{
+ return crypto_register_alg(&alg);
+}
+module_init(nx842_crypto_mod_init);
+
+static void __exit nx842_crypto_mod_exit(void)
+{
+ crypto_unregister_alg(&alg);
+}
+module_exit(nx842_crypto_mod_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("IBM PowerPC Nest (NX) 842 Hardware Compression Interface");
+MODULE_ALIAS_CRYPTO("842");
+MODULE_ALIAS_CRYPTO("842-nx");
+MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff