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-rw-r--r--arch/powerpc/crypto/sha256_spe_glue.c275
1 files changed, 275 insertions, 0 deletions
diff --git a/arch/powerpc/crypto/sha256_spe_glue.c b/arch/powerpc/crypto/sha256_spe_glue.c
new file mode 100644
index 000000000000..f4a616fe1a82
--- /dev/null
+++ b/arch/powerpc/crypto/sha256_spe_glue.c
@@ -0,0 +1,275 @@
+/*
+ * Glue code for SHA-256 implementation for SPE instructions (PPC)
+ *
+ * Based on generic implementation. The assembler module takes care
+ * about the SPE registers so it can run from interrupt context.
+ *
+ * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
+ *
+ * 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.
+ *
+ */
+
+#include <crypto/internal/hash.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/cryptohash.h>
+#include <linux/types.h>
+#include <crypto/sha.h>
+#include <asm/byteorder.h>
+#include <asm/switch_to.h>
+#include <linux/hardirq.h>
+
+/*
+ * MAX_BYTES defines the number of bytes that are allowed to be processed
+ * between preempt_disable() and preempt_enable(). SHA256 takes ~2,000
+ * operations per 64 bytes. e500 cores can issue two arithmetic instructions
+ * per clock cycle using one 32/64 bit unit (SU1) and one 32 bit unit (SU2).
+ * Thus 1KB of input data will need an estimated maximum of 18,000 cycles.
+ * Headroom for cache misses included. Even with the low end model clocked
+ * at 667 MHz this equals to a critical time window of less than 27us.
+ *
+ */
+#define MAX_BYTES 1024
+
+extern void ppc_spe_sha256_transform(u32 *state, const u8 *src, u32 blocks);
+
+static void spe_begin(void)
+{
+ /* We just start SPE operations and will save SPE registers later. */
+ preempt_disable();
+ enable_kernel_spe();
+}
+
+static void spe_end(void)
+{
+ /* reenable preemption */
+ preempt_enable();
+}
+
+static inline void ppc_sha256_clear_context(struct sha256_state *sctx)
+{
+ int count = sizeof(struct sha256_state) >> 2;
+ u32 *ptr = (u32 *)sctx;
+
+ /* make sure we can clear the fast way */
+ BUILD_BUG_ON(sizeof(struct sha256_state) % 4);
+ do { *ptr++ = 0; } while (--count);
+}
+
+static int ppc_spe_sha256_init(struct shash_desc *desc)
+{
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+
+ sctx->state[0] = SHA256_H0;
+ sctx->state[1] = SHA256_H1;
+ sctx->state[2] = SHA256_H2;
+ sctx->state[3] = SHA256_H3;
+ sctx->state[4] = SHA256_H4;
+ sctx->state[5] = SHA256_H5;
+ sctx->state[6] = SHA256_H6;
+ sctx->state[7] = SHA256_H7;
+ sctx->count = 0;
+
+ return 0;
+}
+
+static int ppc_spe_sha224_init(struct shash_desc *desc)
+{
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+
+ sctx->state[0] = SHA224_H0;
+ sctx->state[1] = SHA224_H1;
+ sctx->state[2] = SHA224_H2;
+ sctx->state[3] = SHA224_H3;
+ sctx->state[4] = SHA224_H4;
+ sctx->state[5] = SHA224_H5;
+ sctx->state[6] = SHA224_H6;
+ sctx->state[7] = SHA224_H7;
+ sctx->count = 0;
+
+ return 0;
+}
+
+static int ppc_spe_sha256_update(struct shash_desc *desc, const u8 *data,
+ unsigned int len)
+{
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+ const unsigned int offset = sctx->count & 0x3f;
+ const unsigned int avail = 64 - offset;
+ unsigned int bytes;
+ const u8 *src = data;
+
+ if (avail > len) {
+ sctx->count += len;
+ memcpy((char *)sctx->buf + offset, src, len);
+ return 0;
+ }
+
+ sctx->count += len;
+
+ if (offset) {
+ memcpy((char *)sctx->buf + offset, src, avail);
+
+ spe_begin();
+ ppc_spe_sha256_transform(sctx->state, (const u8 *)sctx->buf, 1);
+ spe_end();
+
+ len -= avail;
+ src += avail;
+ }
+
+ while (len > 63) {
+ /* cut input data into smaller blocks */
+ bytes = (len > MAX_BYTES) ? MAX_BYTES : len;
+ bytes = bytes & ~0x3f;
+
+ spe_begin();
+ ppc_spe_sha256_transform(sctx->state, src, bytes >> 6);
+ spe_end();
+
+ src += bytes;
+ len -= bytes;
+ };
+
+ memcpy((char *)sctx->buf, src, len);
+ return 0;
+}
+
+static int ppc_spe_sha256_final(struct shash_desc *desc, u8 *out)
+{
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+ const unsigned int offset = sctx->count & 0x3f;
+ char *p = (char *)sctx->buf + offset;
+ int padlen;
+ __be64 *pbits = (__be64 *)(((char *)&sctx->buf) + 56);
+ __be32 *dst = (__be32 *)out;
+
+ padlen = 55 - offset;
+ *p++ = 0x80;
+
+ spe_begin();
+
+ if (padlen < 0) {
+ memset(p, 0x00, padlen + sizeof (u64));
+ ppc_spe_sha256_transform(sctx->state, sctx->buf, 1);
+ p = (char *)sctx->buf;
+ padlen = 56;
+ }
+
+ memset(p, 0, padlen);
+ *pbits = cpu_to_be64(sctx->count << 3);
+ ppc_spe_sha256_transform(sctx->state, sctx->buf, 1);
+
+ spe_end();
+
+ dst[0] = cpu_to_be32(sctx->state[0]);
+ dst[1] = cpu_to_be32(sctx->state[1]);
+ dst[2] = cpu_to_be32(sctx->state[2]);
+ dst[3] = cpu_to_be32(sctx->state[3]);
+ dst[4] = cpu_to_be32(sctx->state[4]);
+ dst[5] = cpu_to_be32(sctx->state[5]);
+ dst[6] = cpu_to_be32(sctx->state[6]);
+ dst[7] = cpu_to_be32(sctx->state[7]);
+
+ ppc_sha256_clear_context(sctx);
+ return 0;
+}
+
+static int ppc_spe_sha224_final(struct shash_desc *desc, u8 *out)
+{
+ u32 D[SHA256_DIGEST_SIZE >> 2];
+ __be32 *dst = (__be32 *)out;
+
+ ppc_spe_sha256_final(desc, (u8 *)D);
+
+ /* avoid bytewise memcpy */
+ dst[0] = D[0];
+ dst[1] = D[1];
+ dst[2] = D[2];
+ dst[3] = D[3];
+ dst[4] = D[4];
+ dst[5] = D[5];
+ dst[6] = D[6];
+
+ /* clear sensitive data */
+ memzero_explicit(D, SHA256_DIGEST_SIZE);
+ return 0;
+}
+
+static int ppc_spe_sha256_export(struct shash_desc *desc, void *out)
+{
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+
+ memcpy(out, sctx, sizeof(*sctx));
+ return 0;
+}
+
+static int ppc_spe_sha256_import(struct shash_desc *desc, const void *in)
+{
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+
+ memcpy(sctx, in, sizeof(*sctx));
+ return 0;
+}
+
+static struct shash_alg algs[2] = { {
+ .digestsize = SHA256_DIGEST_SIZE,
+ .init = ppc_spe_sha256_init,
+ .update = ppc_spe_sha256_update,
+ .final = ppc_spe_sha256_final,
+ .export = ppc_spe_sha256_export,
+ .import = ppc_spe_sha256_import,
+ .descsize = sizeof(struct sha256_state),
+ .statesize = sizeof(struct sha256_state),
+ .base = {
+ .cra_name = "sha256",
+ .cra_driver_name= "sha256-ppc-spe",
+ .cra_priority = 300,
+ .cra_flags = CRYPTO_ALG_TYPE_SHASH,
+ .cra_blocksize = SHA256_BLOCK_SIZE,
+ .cra_module = THIS_MODULE,
+ }
+}, {
+ .digestsize = SHA224_DIGEST_SIZE,
+ .init = ppc_spe_sha224_init,
+ .update = ppc_spe_sha256_update,
+ .final = ppc_spe_sha224_final,
+ .export = ppc_spe_sha256_export,
+ .import = ppc_spe_sha256_import,
+ .descsize = sizeof(struct sha256_state),
+ .statesize = sizeof(struct sha256_state),
+ .base = {
+ .cra_name = "sha224",
+ .cra_driver_name= "sha224-ppc-spe",
+ .cra_priority = 300,
+ .cra_flags = CRYPTO_ALG_TYPE_SHASH,
+ .cra_blocksize = SHA224_BLOCK_SIZE,
+ .cra_module = THIS_MODULE,
+ }
+} };
+
+static int __init ppc_spe_sha256_mod_init(void)
+{
+ return crypto_register_shashes(algs, ARRAY_SIZE(algs));
+}
+
+static void __exit ppc_spe_sha256_mod_fini(void)
+{
+ crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
+}
+
+module_init(ppc_spe_sha256_mod_init);
+module_exit(ppc_spe_sha256_mod_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SHA-224 and SHA-256 Secure Hash Algorithm, SPE optimized");
+
+MODULE_ALIAS_CRYPTO("sha224");
+MODULE_ALIAS_CRYPTO("sha224-ppc-spe");
+MODULE_ALIAS_CRYPTO("sha256");
+MODULE_ALIAS_CRYPTO("sha256-ppc-spe");

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