/* * 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 propogate 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; BUG_ON(!sg); 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; } BUG_ON(sg_add); 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);