// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * Synchronous Compression operations
   *
   * Copyright 2015 LG Electronics Inc.
   * Copyright (c) 2016, Intel Corporation
   * Author: Giovanni Cabiddu <giovanni.cabiddu@intel.com>

   */
  #include <linux/errno.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/seq_file.h>
  #include <linux/slab.h>
  #include <linux/string.h>
  #include <linux/crypto.h>

  #include <linux/compiler.h>

  #include <linux/vmalloc.h>
  #include <crypto/algapi.h>
  #include <linux/cryptouser.h>
  #include <net/netlink.h>
  #include <linux/scatterlist.h>
  #include <crypto/scatterwalk.h>
  #include <crypto/internal/acompress.h>
  #include <crypto/internal/scompress.h>
  #include "internal.h"

  struct scomp_scratch {
  	spinlock_t	lock;
  	void		*src;
  	void		*dst;
  };
  
  static DEFINE_PER_CPU(struct scomp_scratch, scomp_scratch) = {
  	.lock = __SPIN_LOCK_UNLOCKED(scomp_scratch.lock),
  };

  static const struct crypto_type crypto_scomp_type;

  static int scomp_scratch_users;
  static DEFINE_MUTEX(scomp_lock);
  
  #ifdef CONFIG_NET
  static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
  {
  	struct crypto_report_comp rscomp;

  	memset(&rscomp, 0, sizeof(rscomp));

  	strscpy(rscomp.type, "scomp", sizeof(rscomp.type));

  	return nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
  		       sizeof(rscomp), &rscomp);

  }
  #else
  static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
  {
  	return -ENOSYS;
  }
  #endif
  
  static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)

  	__maybe_unused;

  
  static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
  {
  	seq_puts(m, "type         : scomp
  ");
  }

  static void crypto_scomp_free_scratches(void)

  {

  	struct scomp_scratch *scratch;

  	int i;

  	for_each_possible_cpu(i) {

  		scratch = per_cpu_ptr(&scomp_scratch, i);

  		vfree(scratch->src);
  		vfree(scratch->dst);
  		scratch->src = NULL;
  		scratch->dst = NULL;
  	}

  }

  static int crypto_scomp_alloc_scratches(void)

  {

  	struct scomp_scratch *scratch;

  	int i;

  	for_each_possible_cpu(i) {

  		void *mem;

  		scratch = per_cpu_ptr(&scomp_scratch, i);

  		mem = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
  		if (!mem)
  			goto error;
  		scratch->src = mem;
  		mem = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
  		if (!mem)
  			goto error;
  		scratch->dst = mem;

  	}
  	return 0;

  error:
  	crypto_scomp_free_scratches();
  	return -ENOMEM;

  }

  static int crypto_scomp_init_tfm(struct crypto_tfm *tfm)
  {

  	int ret = 0;

  
  	mutex_lock(&scomp_lock);

  	if (!scomp_scratch_users++)
  		ret = crypto_scomp_alloc_scratches();

  	mutex_unlock(&scomp_lock);
  
  	return ret;
  }

  static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
  {
  	struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
  	void **tfm_ctx = acomp_tfm_ctx(tfm);
  	struct crypto_scomp *scomp = *tfm_ctx;
  	void **ctx = acomp_request_ctx(req);

  	struct scomp_scratch *scratch;

  	int ret;

  	if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE)
  		return -EINVAL;

  	if (req->dst && !req->dlen)
  		return -EINVAL;

  
  	if (!req->dlen || req->dlen > SCOMP_SCRATCH_SIZE)
  		req->dlen = SCOMP_SCRATCH_SIZE;

  	scratch = raw_cpu_ptr(&scomp_scratch);
  	spin_lock(&scratch->lock);
  
  	scatterwalk_map_and_copy(scratch->src, req->src, 0, req->slen, 0);

  	if (dir)

  		ret = crypto_scomp_compress(scomp, scratch->src, req->slen,
  					    scratch->dst, &req->dlen, *ctx);

  	else

  		ret = crypto_scomp_decompress(scomp, scratch->src, req->slen,
  					      scratch->dst, &req->dlen, *ctx);

  	if (!ret) {
  		if (!req->dst) {

  			req->dst = sgl_alloc(req->dlen, GFP_ATOMIC, NULL);

  			if (!req->dst) {
  				ret = -ENOMEM;

  				goto out;

  			}

  		}

  		scatterwalk_map_and_copy(scratch->dst, req->dst, 0, req->dlen,

  					 1);
  	}
  out:

  	spin_unlock(&scratch->lock);

  	return ret;
  }
  
  static int scomp_acomp_compress(struct acomp_req *req)
  {
  	return scomp_acomp_comp_decomp(req, 1);
  }
  
  static int scomp_acomp_decompress(struct acomp_req *req)
  {
  	return scomp_acomp_comp_decomp(req, 0);
  }
  
  static void crypto_exit_scomp_ops_async(struct crypto_tfm *tfm)
  {
  	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
  
  	crypto_free_scomp(*ctx);

  
  	mutex_lock(&scomp_lock);

  	if (!--scomp_scratch_users)
  		crypto_scomp_free_scratches();

  	mutex_unlock(&scomp_lock);

  }
  
  int crypto_init_scomp_ops_async(struct crypto_tfm *tfm)
  {
  	struct crypto_alg *calg = tfm->__crt_alg;
  	struct crypto_acomp *crt = __crypto_acomp_tfm(tfm);
  	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
  	struct crypto_scomp *scomp;
  
  	if (!crypto_mod_get(calg))
  		return -EAGAIN;
  
  	scomp = crypto_create_tfm(calg, &crypto_scomp_type);
  	if (IS_ERR(scomp)) {
  		crypto_mod_put(calg);
  		return PTR_ERR(scomp);
  	}
  
  	*ctx = scomp;
  	tfm->exit = crypto_exit_scomp_ops_async;
  
  	crt->compress = scomp_acomp_compress;
  	crt->decompress = scomp_acomp_decompress;

  	crt->dst_free = sgl_free;

  	crt->reqsize = sizeof(void *);
  
  	return 0;
  }
  
  struct acomp_req *crypto_acomp_scomp_alloc_ctx(struct acomp_req *req)
  {
  	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
  	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
  	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
  	struct crypto_scomp *scomp = *tfm_ctx;
  	void *ctx;
  
  	ctx = crypto_scomp_alloc_ctx(scomp);
  	if (IS_ERR(ctx)) {
  		kfree(req);
  		return NULL;
  	}
  
  	*req->__ctx = ctx;
  
  	return req;
  }
  
  void crypto_acomp_scomp_free_ctx(struct acomp_req *req)
  {
  	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
  	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
  	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
  	struct crypto_scomp *scomp = *tfm_ctx;
  	void *ctx = *req->__ctx;
  
  	if (ctx)
  		crypto_scomp_free_ctx(scomp, ctx);
  }
  
  static const struct crypto_type crypto_scomp_type = {
  	.extsize = crypto_alg_extsize,
  	.init_tfm = crypto_scomp_init_tfm,
  #ifdef CONFIG_PROC_FS
  	.show = crypto_scomp_show,
  #endif
  	.report = crypto_scomp_report,
  	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
  	.maskset = CRYPTO_ALG_TYPE_MASK,
  	.type = CRYPTO_ALG_TYPE_SCOMPRESS,
  	.tfmsize = offsetof(struct crypto_scomp, base),
  };
  
  int crypto_register_scomp(struct scomp_alg *alg)
  {
  	struct crypto_alg *base = &alg->base;

  
  	base->cra_type = &crypto_scomp_type;
  	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
  	base->cra_flags |= CRYPTO_ALG_TYPE_SCOMPRESS;

  	return crypto_register_alg(base);

  }
  EXPORT_SYMBOL_GPL(crypto_register_scomp);
  
  int crypto_unregister_scomp(struct scomp_alg *alg)
  {

  	return crypto_unregister_alg(&alg->base);

  }
  EXPORT_SYMBOL_GPL(crypto_unregister_scomp);

  int crypto_register_scomps(struct scomp_alg *algs, int count)
  {
  	int i, ret;
  
  	for (i = 0; i < count; i++) {
  		ret = crypto_register_scomp(&algs[i]);
  		if (ret)
  			goto err;
  	}
  
  	return 0;
  
  err:
  	for (--i; i >= 0; --i)
  		crypto_unregister_scomp(&algs[i]);
  
  	return ret;
  }
  EXPORT_SYMBOL_GPL(crypto_register_scomps);
  
  void crypto_unregister_scomps(struct scomp_alg *algs, int count)
  {
  	int i;
  
  	for (i = count - 1; i >= 0; --i)
  		crypto_unregister_scomp(&algs[i]);
  }
  EXPORT_SYMBOL_GPL(crypto_unregister_scomps);

  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION("Synchronous compression type");