WTF: patch "[PATCH] crypto: qat - add backlog mechanism" was seriously submitted to be applied to the 5.18-stable tree?

The patch below was submitted to be applied to the 5.18-stable tree.

I fail to see how this patch meets the stable kernel rules as found at Documentation/process/stable-kernel-rules.rst.

I could be totally wrong, and if so, please respond to stable@vger.kernel.org and let me know why this patch should be applied. Otherwise, it is now dropped from my patch queues, never to be seen again.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 38682383973280e5be2802ba8a8d4a636d36cb19 Mon Sep 17 00:00:00 2001 From: Giovanni Cabiddu giovanni.cabiddu@intel.com Date: Mon, 9 May 2022 14:34:10 +0100 Subject: [PATCH] crypto: qat - add backlog mechanism

The implementations of the crypto algorithms (aead, skcipher, etc) in the QAT driver do not properly support requests with the CRYPTO_TFM_REQ_MAY_BACKLOG flag set. If the HW queue is full, the driver returns -EBUSY but does not enqueue the request. This can result in applications like dm-crypt waiting indefinitely for the completion of a request that was never submitted to the hardware.

Fix this by adding a software backlog queue: if the ring buffer is more than eighty percent full, then the request is enqueued to a backlog list and the error code -EBUSY is returned back to the caller. Requests in the backlog queue are resubmitted at a later time, in the context of the callback of a previously submitted request. The request for which -EBUSY is returned is then marked as -EINPROGRESS once submitted to the HW queues.

The submission loop inside the function qat_alg_send_message() has been modified to decide which submission policy to use based on the request flags. If the request does not have the CRYPTO_TFM_REQ_MAY_BACKLOG set, the previous behaviour has been preserved.

Based on a patch by Vishnu Das Ramachandran vishnu.dasx.ramachandran@intel.com

Cc: stable@vger.kernel.org Fixes: d370cec32194 ("crypto: qat - Intel(R) QAT crypto interface") Reported-by: Mikulas Patocka mpatocka@redhat.com Reported-by: Kyle Sanderson kyle.leet@gmail.com Signed-off-by: Giovanni Cabiddu giovanni.cabiddu@intel.com Reviewed-by: Marco Chiappero marco.chiappero@intel.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au

diff --git a/drivers/crypto/qat/qat_common/adf_transport.c b/drivers/crypto/qat/qat_common/adf_transport.c index 8ba28409fb74..630d0483c4e0 100644 --- a/drivers/crypto/qat/qat_common/adf_transport.c +++ b/drivers/crypto/qat/qat_common/adf_transport.c @@ -8,6 +8,9 @@ #include "adf_cfg.h" #include "adf_common_drv.h"

+#define ADF_MAX_RING_THRESHOLD 80 +#define ADF_PERCENT(tot, percent) (((tot) * (percent)) / 100) + static inline u32 adf_modulo(u32 data, u32 shift) { u32 div = data >> shift; @@ -77,6 +80,11 @@ static void adf_disable_ring_irq(struct adf_etr_bank_data *bank, u32 ring) bank->irq_mask); }

+bool adf_ring_nearly_full(struct adf_etr_ring_data *ring) +{ + return atomic_read(ring->inflights) > ring->threshold; +} + int adf_send_message(struct adf_etr_ring_data *ring, u32 *msg) { struct adf_hw_csr_ops *csr_ops = GET_CSR_OPS(ring->bank->accel_dev); @@ -217,6 +225,7 @@ int adf_create_ring(struct adf_accel_dev *accel_dev, const char *section, struct adf_etr_bank_data *bank; struct adf_etr_ring_data *ring; char val[ADF_CFG_MAX_VAL_LEN_IN_BYTES]; + int max_inflights; u32 ring_num; int ret;

@@ -263,6 +272,8 @@ int adf_create_ring(struct adf_accel_dev *accel_dev, const char *section, ring->ring_size = adf_verify_ring_size(msg_size, num_msgs); ring->head = 0; ring->tail = 0; + max_inflights = ADF_MAX_INFLIGHTS(ring->ring_size, ring->msg_size); + ring->threshold = ADF_PERCENT(max_inflights, ADF_MAX_RING_THRESHOLD); atomic_set(ring->inflights, 0); ret = adf_init_ring(ring); if (ret) diff --git a/drivers/crypto/qat/qat_common/adf_transport.h b/drivers/crypto/qat/qat_common/adf_transport.h index 2c95f1697c76..e6ef6f9b7691 100644 --- a/drivers/crypto/qat/qat_common/adf_transport.h +++ b/drivers/crypto/qat/qat_common/adf_transport.h @@ -14,6 +14,7 @@ int adf_create_ring(struct adf_accel_dev *accel_dev, const char *section, const char *ring_name, adf_callback_fn callback, int poll_mode, struct adf_etr_ring_data **ring_ptr);

+bool adf_ring_nearly_full(struct adf_etr_ring_data *ring); int adf_send_message(struct adf_etr_ring_data *ring, u32 *msg); void adf_remove_ring(struct adf_etr_ring_data *ring); #endif diff --git a/drivers/crypto/qat/qat_common/adf_transport_internal.h b/drivers/crypto/qat/qat_common/adf_transport_internal.h index 501bcf0f1809..8b2c92ba7ca1 100644 --- a/drivers/crypto/qat/qat_common/adf_transport_internal.h +++ b/drivers/crypto/qat/qat_common/adf_transport_internal.h @@ -22,6 +22,7 @@ struct adf_etr_ring_data { spinlock_t lock; /* protects ring data struct */ u16 head; u16 tail; + u32 threshold; u8 ring_number; u8 ring_size; u8 msg_size; diff --git a/drivers/crypto/qat/qat_common/qat_algs.c b/drivers/crypto/qat/qat_common/qat_algs.c index 6017ae82c713..873533dc43a7 100644 --- a/drivers/crypto/qat/qat_common/qat_algs.c +++ b/drivers/crypto/qat/qat_common/qat_algs.c @@ -935,19 +935,25 @@ void qat_alg_callback(void *resp) struct icp_qat_fw_la_resp *qat_resp = resp; struct qat_crypto_request *qat_req = (void *)(__force long)qat_resp->opaque_data; + struct qat_instance_backlog *backlog = qat_req->alg_req.backlog;

qat_req->cb(qat_resp, qat_req); + + qat_alg_send_backlog(backlog); }

static int qat_alg_send_sym_message(struct qat_crypto_request *qat_req, - struct qat_crypto_instance *inst) + struct qat_crypto_instance *inst, + struct crypto_async_request *base) { - struct qat_alg_req req; + struct qat_alg_req *alg_req = &qat_req->alg_req;

- req.fw_req = (u32 *)&qat_req->req; - req.tx_ring = inst->sym_tx; + alg_req->fw_req = (u32 *)&qat_req->req; + alg_req->tx_ring = inst->sym_tx; + alg_req->base = base; + alg_req->backlog = &inst->backlog;

- return qat_alg_send_message(&req); + return qat_alg_send_message(alg_req); }

static int qat_alg_aead_dec(struct aead_request *areq) @@ -987,7 +993,7 @@ static int qat_alg_aead_dec(struct aead_request *areq) auth_param->auth_off = 0; auth_param->auth_len = areq->assoclen + cipher_param->cipher_length;

- ret = qat_alg_send_sym_message(qat_req, ctx->inst); + ret = qat_alg_send_sym_message(qat_req, ctx->inst, &areq->base); if (ret == -ENOSPC) qat_alg_free_bufl(ctx->inst, qat_req);

@@ -1031,7 +1037,7 @@ static int qat_alg_aead_enc(struct aead_request *areq) auth_param->auth_off = 0; auth_param->auth_len = areq->assoclen + areq->cryptlen;

- ret = qat_alg_send_sym_message(qat_req, ctx->inst); + ret = qat_alg_send_sym_message(qat_req, ctx->inst, &areq->base); if (ret == -ENOSPC) qat_alg_free_bufl(ctx->inst, qat_req);

@@ -1212,7 +1218,7 @@ static int qat_alg_skcipher_encrypt(struct skcipher_request *req)

qat_alg_set_req_iv(qat_req);

- ret = qat_alg_send_sym_message(qat_req, ctx->inst); + ret = qat_alg_send_sym_message(qat_req, ctx->inst, &req->base); if (ret == -ENOSPC) qat_alg_free_bufl(ctx->inst, qat_req);

@@ -1278,7 +1284,7 @@ static int qat_alg_skcipher_decrypt(struct skcipher_request *req) qat_alg_set_req_iv(qat_req); qat_alg_update_iv(qat_req);

- ret = qat_alg_send_sym_message(qat_req, ctx->inst); + ret = qat_alg_send_sym_message(qat_req, ctx->inst, &req->base); if (ret == -ENOSPC) qat_alg_free_bufl(ctx->inst, qat_req);

diff --git a/drivers/crypto/qat/qat_common/qat_algs_send.c b/drivers/crypto/qat/qat_common/qat_algs_send.c index 78f1bb8c26c0..ff5b4347f783 100644 --- a/drivers/crypto/qat/qat_common/qat_algs_send.c +++ b/drivers/crypto/qat/qat_common/qat_algs_send.c @@ -6,7 +6,7 @@

#define ADF_MAX_RETRIES 20

-int qat_alg_send_message(struct qat_alg_req *req) +static int qat_alg_send_message_retry(struct qat_alg_req *req) { int ret = 0, ctr = 0;

@@ -19,3 +19,68 @@ int qat_alg_send_message(struct qat_alg_req *req)

return -EINPROGRESS; } + +void qat_alg_send_backlog(struct qat_instance_backlog *backlog) +{ + struct qat_alg_req *req, *tmp; + + spin_lock_bh(&backlog->lock); + list_for_each_entry_safe(req, tmp, &backlog->list, list) { + if (adf_send_message(req->tx_ring, req->fw_req)) { + /* The HW ring is full. Do nothing. + * qat_alg_send_backlog() will be invoked again by + * another callback. + */ + break; + } + list_del(&req->list); + req->base->complete(req->base, -EINPROGRESS); + } + spin_unlock_bh(&backlog->lock); +} + +static void qat_alg_backlog_req(struct qat_alg_req *req, + struct qat_instance_backlog *backlog) +{ + INIT_LIST_HEAD(&req->list); + + spin_lock_bh(&backlog->lock); + list_add_tail(&req->list, &backlog->list); + spin_unlock_bh(&backlog->lock); +} + +static int qat_alg_send_message_maybacklog(struct qat_alg_req *req) +{ + struct qat_instance_backlog *backlog = req->backlog; + struct adf_etr_ring_data *tx_ring = req->tx_ring; + u32 *fw_req = req->fw_req; + + /* If any request is already backlogged, then add to backlog list */ + if (!list_empty(&backlog->list)) + goto enqueue; + + /* If ring is nearly full, then add to backlog list */ + if (adf_ring_nearly_full(tx_ring)) + goto enqueue; + + /* If adding request to HW ring fails, then add to backlog list */ + if (adf_send_message(tx_ring, fw_req)) + goto enqueue; + + return -EINPROGRESS; + +enqueue: + qat_alg_backlog_req(req, backlog); + + return -EBUSY; +} + +int qat_alg_send_message(struct qat_alg_req *req) +{ + u32 flags = req->base->flags; + + if (flags & CRYPTO_TFM_REQ_MAY_BACKLOG) + return qat_alg_send_message_maybacklog(req); + else + return qat_alg_send_message_retry(req); +} diff --git a/drivers/crypto/qat/qat_common/qat_algs_send.h b/drivers/crypto/qat/qat_common/qat_algs_send.h index 3fa685d0c293..5ce9f4f69d8f 100644 --- a/drivers/crypto/qat/qat_common/qat_algs_send.h +++ b/drivers/crypto/qat/qat_common/qat_algs_send.h @@ -6,5 +6,6 @@ #include "qat_crypto.h"

int qat_alg_send_message(struct qat_alg_req *req); +void qat_alg_send_backlog(struct qat_instance_backlog *backlog);

#endif diff --git a/drivers/crypto/qat/qat_common/qat_asym_algs.c b/drivers/crypto/qat/qat_common/qat_asym_algs.c index 08b8d83e070a..ff7249c093c9 100644 --- a/drivers/crypto/qat/qat_common/qat_asym_algs.c +++ b/drivers/crypto/qat/qat_common/qat_asym_algs.c @@ -136,17 +136,21 @@ struct qat_asym_request { } areq; int err; void (*cb)(struct icp_qat_fw_pke_resp *resp); + struct qat_alg_req alg_req; } __aligned(64);

static int qat_alg_send_asym_message(struct qat_asym_request *qat_req, - struct qat_crypto_instance *inst) + struct qat_crypto_instance *inst, + struct crypto_async_request *base) { - struct qat_alg_req req; + struct qat_alg_req *alg_req = &qat_req->alg_req;

- req.fw_req = (u32 *)&qat_req->req; - req.tx_ring = inst->pke_tx; + alg_req->fw_req = (u32 *)&qat_req->req; + alg_req->tx_ring = inst->pke_tx; + alg_req->base = base; + alg_req->backlog = &inst->backlog;

- return qat_alg_send_message(&req); + return qat_alg_send_message(alg_req); }

static void qat_dh_cb(struct icp_qat_fw_pke_resp *resp) @@ -350,7 +354,7 @@ static int qat_dh_compute_value(struct kpp_request *req) msg->input_param_count = n_input_params; msg->output_param_count = 1;

- ret = qat_alg_send_asym_message(qat_req, ctx->inst); + ret = qat_alg_send_asym_message(qat_req, inst, &req->base); if (ret == -ENOSPC) goto unmap_all;

@@ -557,8 +561,11 @@ void qat_alg_asym_callback(void *_resp) { struct icp_qat_fw_pke_resp *resp = _resp; struct qat_asym_request *areq = (void *)(__force long)resp->opaque; + struct qat_instance_backlog *backlog = areq->alg_req.backlog;

areq->cb(resp); + + qat_alg_send_backlog(backlog); }

#define PKE_RSA_EP_512 0x1c161b21 @@ -748,7 +755,7 @@ static int qat_rsa_enc(struct akcipher_request *req) msg->input_param_count = 3; msg->output_param_count = 1;

- ret = qat_alg_send_asym_message(qat_req, ctx->inst); + ret = qat_alg_send_asym_message(qat_req, inst, &req->base); if (ret == -ENOSPC) goto unmap_all;

@@ -901,7 +908,7 @@ static int qat_rsa_dec(struct akcipher_request *req)

msg->output_param_count = 1;

- ret = qat_alg_send_asym_message(qat_req, ctx->inst); + ret = qat_alg_send_asym_message(qat_req, inst, &req->base); if (ret == -ENOSPC) goto unmap_all;

diff --git a/drivers/crypto/qat/qat_common/qat_crypto.c b/drivers/crypto/qat/qat_common/qat_crypto.c index 67c9588e89df..80d905ed102e 100644 --- a/drivers/crypto/qat/qat_common/qat_crypto.c +++ b/drivers/crypto/qat/qat_common/qat_crypto.c @@ -353,6 +353,9 @@ static int qat_crypto_create_instances(struct adf_accel_dev *accel_dev) &inst->pke_rx); if (ret) goto err; + + INIT_LIST_HEAD(&inst->backlog.list); + spin_lock_init(&inst->backlog.lock); } return 0; err: diff --git a/drivers/crypto/qat/qat_common/qat_crypto.h b/drivers/crypto/qat/qat_common/qat_crypto.h index 0dcba6fc358c..245b6d9a3650 100644 --- a/drivers/crypto/qat/qat_common/qat_crypto.h +++ b/drivers/crypto/qat/qat_common/qat_crypto.h @@ -9,9 +9,17 @@ #include "adf_accel_devices.h" #include "icp_qat_fw_la.h"

+struct qat_instance_backlog { + struct list_head list; + spinlock_t lock; /* protects backlog list */ +}; + struct qat_alg_req { u32 *fw_req; struct adf_etr_ring_data *tx_ring; + struct crypto_async_request *base; + struct list_head list; + struct qat_instance_backlog *backlog; };

struct qat_crypto_instance { @@ -24,6 +32,7 @@ struct qat_crypto_instance { unsigned long state; int id; atomic_t refctr; + struct qat_instance_backlog backlog; };

#define QAT_MAX_BUFF_DESC 4 @@ -82,6 +91,7 @@ struct qat_crypto_request { u8 iv[AES_BLOCK_SIZE]; }; bool encryption; + struct qat_alg_req alg_req; };

static inline bool adf_hw_dev_has_crypto(struct adf_accel_dev *accel_dev)