blob: e0380e59c361f3624af6d61caaa7efc47a0986ee [file] [log] [blame]
/*
* AMD Cryptographic Coprocessor (CCP) crypto API support
*
* Copyright (C) 2013 Advanced Micro Devices, Inc.
*
* Author: Tom Lendacky <thomas.lendacky@amd.com>
*
* 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.
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/ccp.h>
#include <linux/scatterlist.h>
#include <crypto/internal/hash.h>
#include "ccp-crypto.h"
MODULE_AUTHOR("Tom Lendacky <thomas.lendacky@amd.com>");
MODULE_LICENSE("GPL");
MODULE_VERSION("1.0.0");
MODULE_DESCRIPTION("AMD Cryptographic Coprocessor crypto API support");
static unsigned int aes_disable;
module_param(aes_disable, uint, 0444);
MODULE_PARM_DESC(aes_disable, "Disable use of AES - any non-zero value");
static unsigned int sha_disable;
module_param(sha_disable, uint, 0444);
MODULE_PARM_DESC(sha_disable, "Disable use of SHA - any non-zero value");
/* List heads for the supported algorithms */
static LIST_HEAD(hash_algs);
static LIST_HEAD(cipher_algs);
/* For any tfm, requests for that tfm must be returned on the order
* received. With multiple queues available, the CCP can process more
* than one cmd at a time. Therefore we must maintain a cmd list to insure
* the proper ordering of requests on a given tfm.
*/
struct ccp_crypto_queue {
struct list_head cmds;
struct list_head *backlog;
unsigned int cmd_count;
};
#define CCP_CRYPTO_MAX_QLEN 100
static struct ccp_crypto_queue req_queue;
static spinlock_t req_queue_lock;
struct ccp_crypto_cmd {
struct list_head entry;
struct ccp_cmd *cmd;
/* Save the crypto_tfm and crypto_async_request addresses
* separately to avoid any reference to a possibly invalid
* crypto_async_request structure after invoking the request
* callback
*/
struct crypto_async_request *req;
struct crypto_tfm *tfm;
/* Used for held command processing to determine state */
int ret;
};
struct ccp_crypto_cpu {
struct work_struct work;
struct completion completion;
struct ccp_crypto_cmd *crypto_cmd;
int err;
};
static inline bool ccp_crypto_success(int err)
{
if (err && (err != -EINPROGRESS) && (err != -EBUSY))
return false;
return true;
}
static struct ccp_crypto_cmd *ccp_crypto_cmd_complete(
struct ccp_crypto_cmd *crypto_cmd, struct ccp_crypto_cmd **backlog)
{
struct ccp_crypto_cmd *held = NULL, *tmp;
unsigned long flags;
*backlog = NULL;
spin_lock_irqsave(&req_queue_lock, flags);
/* Held cmds will be after the current cmd in the queue so start
* searching for a cmd with a matching tfm for submission.
*/
tmp = crypto_cmd;
list_for_each_entry_continue(tmp, &req_queue.cmds, entry) {
if (crypto_cmd->tfm != tmp->tfm)
continue;
held = tmp;
break;
}
/* Process the backlog:
* Because cmds can be executed from any point in the cmd list
* special precautions have to be taken when handling the backlog.
*/
if (req_queue.backlog != &req_queue.cmds) {
/* Skip over this cmd if it is the next backlog cmd */
if (req_queue.backlog == &crypto_cmd->entry)
req_queue.backlog = crypto_cmd->entry.next;
*backlog = container_of(req_queue.backlog,
struct ccp_crypto_cmd, entry);
req_queue.backlog = req_queue.backlog->next;
/* Skip over this cmd if it is now the next backlog cmd */
if (req_queue.backlog == &crypto_cmd->entry)
req_queue.backlog = crypto_cmd->entry.next;
}
/* Remove the cmd entry from the list of cmds */
req_queue.cmd_count--;
list_del(&crypto_cmd->entry);
spin_unlock_irqrestore(&req_queue_lock, flags);
return held;
}
static void ccp_crypto_complete(void *data, int err)
{
struct ccp_crypto_cmd *crypto_cmd = data;
struct ccp_crypto_cmd *held, *next, *backlog;
struct crypto_async_request *req = crypto_cmd->req;
struct ccp_ctx *ctx = crypto_tfm_ctx(req->tfm);
int ret;
if (err == -EINPROGRESS) {
/* Only propagate the -EINPROGRESS if necessary */
if (crypto_cmd->ret == -EBUSY) {
crypto_cmd->ret = -EINPROGRESS;
req->complete(req, -EINPROGRESS);
}
return;
}
/* Operation has completed - update the queue before invoking
* the completion callbacks and retrieve the next cmd (cmd with
* a matching tfm) that can be submitted to the CCP.
*/
held = ccp_crypto_cmd_complete(crypto_cmd, &backlog);
if (backlog) {
backlog->ret = -EINPROGRESS;
backlog->req->complete(backlog->req, -EINPROGRESS);
}
/* Transition the state from -EBUSY to -EINPROGRESS first */
if (crypto_cmd->ret == -EBUSY)
req->complete(req, -EINPROGRESS);
/* Completion callbacks */
ret = err;
if (ctx->complete)
ret = ctx->complete(req, ret);
req->complete(req, ret);
/* Submit the next cmd */
while (held) {
/* Since we have already queued the cmd, we must indicate that
* we can backlog so as not to "lose" this request.
*/
held->cmd->flags |= CCP_CMD_MAY_BACKLOG;
ret = ccp_enqueue_cmd(held->cmd);
if (ccp_crypto_success(ret))
break;
/* Error occurred, report it and get the next entry */
ctx = crypto_tfm_ctx(held->req->tfm);
if (ctx->complete)
ret = ctx->complete(held->req, ret);
held->req->complete(held->req, ret);
next = ccp_crypto_cmd_complete(held, &backlog);
if (backlog) {
backlog->ret = -EINPROGRESS;
backlog->req->complete(backlog->req, -EINPROGRESS);
}
kfree(held);
held = next;
}
kfree(crypto_cmd);
}
static int ccp_crypto_enqueue_cmd(struct ccp_crypto_cmd *crypto_cmd)
{
struct ccp_crypto_cmd *active = NULL, *tmp;
unsigned long flags;
bool free_cmd = true;
int ret;
spin_lock_irqsave(&req_queue_lock, flags);
/* Check if the cmd can/should be queued */
if (req_queue.cmd_count >= CCP_CRYPTO_MAX_QLEN) {
ret = -EBUSY;
if (!(crypto_cmd->cmd->flags & CCP_CMD_MAY_BACKLOG))
goto e_lock;
}
/* Look for an entry with the same tfm. If there is a cmd
* with the same tfm in the list then the current cmd cannot
* be submitted to the CCP yet.
*/
list_for_each_entry(tmp, &req_queue.cmds, entry) {
if (crypto_cmd->tfm != tmp->tfm)
continue;
active = tmp;
break;
}
ret = -EINPROGRESS;
if (!active) {
ret = ccp_enqueue_cmd(crypto_cmd->cmd);
if (!ccp_crypto_success(ret))
goto e_lock; /* Error, don't queue it */
if ((ret == -EBUSY) &&
!(crypto_cmd->cmd->flags & CCP_CMD_MAY_BACKLOG))
goto e_lock; /* Not backlogging, don't queue it */
}
if (req_queue.cmd_count >= CCP_CRYPTO_MAX_QLEN) {
ret = -EBUSY;
if (req_queue.backlog == &req_queue.cmds)
req_queue.backlog = &crypto_cmd->entry;
}
crypto_cmd->ret = ret;
req_queue.cmd_count++;
list_add_tail(&crypto_cmd->entry, &req_queue.cmds);
free_cmd = false;
e_lock:
spin_unlock_irqrestore(&req_queue_lock, flags);
if (free_cmd)
kfree(crypto_cmd);
return ret;
}
/**
* ccp_crypto_enqueue_request - queue an crypto async request for processing
* by the CCP
*
* @req: crypto_async_request struct to be processed
* @cmd: ccp_cmd struct to be sent to the CCP
*/
int ccp_crypto_enqueue_request(struct crypto_async_request *req,
struct ccp_cmd *cmd)
{
struct ccp_crypto_cmd *crypto_cmd;
gfp_t gfp;
gfp = req->flags & CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL : GFP_ATOMIC;
crypto_cmd = kzalloc(sizeof(*crypto_cmd), gfp);
if (!crypto_cmd)
return -ENOMEM;
/* The tfm pointer must be saved and not referenced from the
* crypto_async_request (req) pointer because it is used after
* completion callback for the request and the req pointer
* might not be valid anymore.
*/
crypto_cmd->cmd = cmd;
crypto_cmd->req = req;
crypto_cmd->tfm = req->tfm;
cmd->callback = ccp_crypto_complete;
cmd->data = crypto_cmd;
if (req->flags & CRYPTO_TFM_REQ_MAY_BACKLOG)
cmd->flags |= CCP_CMD_MAY_BACKLOG;
else
cmd->flags &= ~CCP_CMD_MAY_BACKLOG;
return ccp_crypto_enqueue_cmd(crypto_cmd);
}
struct scatterlist *ccp_crypto_sg_table_add(struct sg_table *table,
struct scatterlist *sg_add)
{
struct scatterlist *sg, *sg_last = NULL;
for (sg = table->sgl; sg; sg = sg_next(sg))
if (!sg_page(sg))
break;
if (WARN_ON(!sg))
return NULL;
for (; sg && sg_add; sg = sg_next(sg), sg_add = sg_next(sg_add)) {
sg_set_page(sg, sg_page(sg_add), sg_add->length,
sg_add->offset);
sg_last = sg;
}
if (WARN_ON(sg_add))
return NULL;
return sg_last;
}
static int ccp_register_algs(void)
{
int ret;
if (!aes_disable) {
ret = ccp_register_aes_algs(&cipher_algs);
if (ret)
return ret;
ret = ccp_register_aes_cmac_algs(&hash_algs);
if (ret)
return ret;
ret = ccp_register_aes_xts_algs(&cipher_algs);
if (ret)
return ret;
}
if (!sha_disable) {
ret = ccp_register_sha_algs(&hash_algs);
if (ret)
return ret;
}
return 0;
}
static void ccp_unregister_algs(void)
{
struct ccp_crypto_ahash_alg *ahash_alg, *ahash_tmp;
struct ccp_crypto_ablkcipher_alg *ablk_alg, *ablk_tmp;
list_for_each_entry_safe(ahash_alg, ahash_tmp, &hash_algs, entry) {
crypto_unregister_ahash(&ahash_alg->alg);
list_del(&ahash_alg->entry);
kfree(ahash_alg);
}
list_for_each_entry_safe(ablk_alg, ablk_tmp, &cipher_algs, entry) {
crypto_unregister_alg(&ablk_alg->alg);
list_del(&ablk_alg->entry);
kfree(ablk_alg);
}
}
static int ccp_crypto_init(void)
{
int ret;
ret = ccp_present();
if (ret)
return ret;
spin_lock_init(&req_queue_lock);
INIT_LIST_HEAD(&req_queue.cmds);
req_queue.backlog = &req_queue.cmds;
req_queue.cmd_count = 0;
ret = ccp_register_algs();
if (ret)
ccp_unregister_algs();
return ret;
}
static void ccp_crypto_exit(void)
{
ccp_unregister_algs();
}
module_init(ccp_crypto_init);
module_exit(ccp_crypto_exit);