As it stands chacha cannot do chaining.  That is, it has to handle
each request as a whole.  This patch adds support for chaining when
the CRYPTO_TFM_REQ_MORE flag is set.
    
Signed-off-by: Herbert Xu <[email protected]>
---

 arch/x86/crypto/chacha_glue.c |   55 +++++++++++++++++++++++++++++-------------
 1 file changed, 39 insertions(+), 16 deletions(-)

diff --git a/arch/x86/crypto/chacha_glue.c b/arch/x86/crypto/chacha_glue.c
index e67a59130025e..96cbdcbfe4f8f 100644
--- a/arch/x86/crypto/chacha_glue.c
+++ b/arch/x86/crypto/chacha_glue.c
@@ -6,14 +6,16 @@
  * Copyright (C) 2015 Martin Willi
  */
 
-#include <crypto/algapi.h>
 #include <crypto/internal/chacha.h>
 #include <crypto/internal/simd.h>
-#include <crypto/internal/skcipher.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <asm/simd.h>
 
+#define CHACHA_STATE_ALIGN 16
+#define CHACHA_REQSIZE sizeof(struct chacha_reqctx) + \
+                      ((CHACHA_STATE_ALIGN - 1) & ~(CRYPTO_MINALIGN - 1))
+
 asmlinkage void chacha_block_xor_ssse3(u32 *state, u8 *dst, const u8 *src,
                                       unsigned int len, int nrounds);
 asmlinkage void chacha_4block_xor_ssse3(u32 *state, u8 *dst, const u8 *src,
@@ -38,6 +40,12 @@ static __ro_after_init 
DEFINE_STATIC_KEY_FALSE(chacha_use_simd);
 static __ro_after_init DEFINE_STATIC_KEY_FALSE(chacha_use_avx2);
 static __ro_after_init DEFINE_STATIC_KEY_FALSE(chacha_use_avx512vl);
 
+static inline struct chacha_reqctx *chacha_request_ctx(
+       struct skcipher_request *req)
+{
+       return PTR_ALIGN(skcipher_request_ctx(req), CHACHA_STATE_ALIGN);
+}
+
 static unsigned int chacha_advance(unsigned int len, unsigned int maxblocks)
 {
        len = min(len, maxblocks * CHACHA_BLOCK_SIZE);
@@ -159,16 +167,16 @@ void chacha_crypt_arch(u32 *state, u8 *dst, const u8 
*src, unsigned int bytes,
 }
 EXPORT_SYMBOL(chacha_crypt_arch);
 
-static int chacha_simd_stream_xor(struct skcipher_request *req,
-                                 const struct chacha_ctx *ctx, const u8 *iv)
+static int chacha_simd_stream_xor(struct skcipher_request *req, int nrounds)
 {
-       u32 state[CHACHA_STATE_WORDS] __aligned(8);
+       struct chacha_reqctx *rctx = chacha_request_ctx(req);
        struct skcipher_walk walk;
+       u32 *state = rctx->state;
        int err;
 
-       err = skcipher_walk_virt(&walk, req, false);
+       rctx->init = req->base.flags & CRYPTO_TFM_REQ_MORE;
 
-       chacha_init_generic(state, ctx->key, iv);
+       err = skcipher_walk_virt(&walk, req, false);
 
        while (walk.nbytes > 0) {
                unsigned int nbytes = walk.nbytes;
@@ -180,12 +188,12 @@ static int chacha_simd_stream_xor(struct skcipher_request 
*req,
                    !crypto_simd_usable()) {
                        chacha_crypt_generic(state, walk.dst.virt.addr,
                                             walk.src.virt.addr, nbytes,
-                                            ctx->nrounds);
+                                            nrounds);
                } else {
                        kernel_fpu_begin();
                        chacha_dosimd(state, walk.dst.virt.addr,
                                      walk.src.virt.addr, nbytes,
-                                     ctx->nrounds);
+                                     nrounds);
                        kernel_fpu_end();
                }
                err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
@@ -197,33 +205,45 @@ static int chacha_simd_stream_xor(struct skcipher_request 
*req,
 static int chacha_simd(struct skcipher_request *req)
 {
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+       struct chacha_reqctx *rctx = chacha_request_ctx(req);
        struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
 
-       return chacha_simd_stream_xor(req, ctx, req->iv);
+       if (!rctx->init)
+               chacha_init_generic(rctx->state, ctx->key, req->iv);
+
+       return chacha_simd_stream_xor(req, ctx->nrounds);
 }
 
 static int xchacha_simd(struct skcipher_request *req)
 {
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+       struct chacha_reqctx *rctx = chacha_request_ctx(req);
        struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
-       u32 state[CHACHA_STATE_WORDS] __aligned(8);
-       struct chacha_ctx subctx;
+       int nrounds = ctx->nrounds;
+       u32 *state = rctx->state;
        u8 real_iv[16];
+       u32 key[8];
+
+       if (rctx->init)
+               goto skip_init;
 
        chacha_init_generic(state, ctx->key, req->iv);
 
        if (req->cryptlen > CHACHA_BLOCK_SIZE && crypto_simd_usable()) {
                kernel_fpu_begin();
-               hchacha_block_ssse3(state, subctx.key, ctx->nrounds);
+               hchacha_block_ssse3(state, key, nrounds);
                kernel_fpu_end();
        } else {
-               hchacha_block_generic(state, subctx.key, ctx->nrounds);
+               hchacha_block_generic(state, key, nrounds);
        }
-       subctx.nrounds = ctx->nrounds;
 
        memcpy(&real_iv[0], req->iv + 24, 8);
        memcpy(&real_iv[8], req->iv + 16, 8);
-       return chacha_simd_stream_xor(req, &subctx, real_iv);
+
+       chacha_init_generic(state, key, real_iv);
+
+skip_init:
+       return chacha_simd_stream_xor(req, nrounds);
 }
 
 static struct skcipher_alg algs[] = {
@@ -239,6 +259,7 @@ static struct skcipher_alg algs[] = {
                .max_keysize            = CHACHA_KEY_SIZE,
                .ivsize                 = CHACHA_IV_SIZE,
                .chunksize              = CHACHA_BLOCK_SIZE,
+               .reqsize                = CHACHA_REQSIZE,
                .setkey                 = chacha20_setkey,
                .encrypt                = chacha_simd,
                .decrypt                = chacha_simd,
@@ -254,6 +275,7 @@ static struct skcipher_alg algs[] = {
                .max_keysize            = CHACHA_KEY_SIZE,
                .ivsize                 = XCHACHA_IV_SIZE,
                .chunksize              = CHACHA_BLOCK_SIZE,
+               .reqsize                = CHACHA_REQSIZE,
                .setkey                 = chacha20_setkey,
                .encrypt                = xchacha_simd,
                .decrypt                = xchacha_simd,
@@ -269,6 +291,7 @@ static struct skcipher_alg algs[] = {
                .max_keysize            = CHACHA_KEY_SIZE,
                .ivsize                 = XCHACHA_IV_SIZE,
                .chunksize              = CHACHA_BLOCK_SIZE,
+               .reqsize                = CHACHA_REQSIZE,
                .setkey                 = chacha12_setkey,
                .encrypt                = xchacha_simd,
                .decrypt                = xchacha_simd,

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