From: Alexandru Porosanu Subject: RE: [PATCH] crypto: caam: add backlogging support Date: Tue, 10 May 2016 14:59:03 +0000 Message-ID: References: <1462540733-2170-1-git-send-email-cata.vasile@nxp.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Cc: "linux-crypto-owner@vger.kernel.org" , Scott Wood To: Horia Ioan Geanta Neag , Catalin Vasile , "linux-crypto@vger.kernel.org" Return-path: Received: from mail-am1on0072.outbound.protection.outlook.com ([157.56.112.72]:34848 "EHLO emea01-am1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751054AbcEJPa5 convert rfc822-to-8bit (ORCPT ); Tue, 10 May 2016 11:30:57 -0400 In-Reply-To: Content-Language: en-US Sender: linux-crypto-owner@vger.kernel.org List-ID: Hi, > -----Original Message----- > From: Horia Ioan Geanta Neag > Sent: Monday, May 09, 2016 5:51 PM > To: Catalin Vasile ; linux-crypto@vger.kernel.org > Cc: linux-crypto-owner@vger.kernel.org; Alexandru Porosanu > ; Scott Wood > Subject: Re: [PATCH] crypto: caam: add backlogging support > > On 5/6/2016 4:19 PM, Catalin Vasile wrote: > > caam_jr_enqueue() function returns -EBUSY once there are no more slots > > available in the JR, but it doesn't actually save the current request. > > This breaks the functionality of users that expect that even if there > > is no more space for the request, it is at least queued for later > > execution. In other words, all crypto transformations that request > > backlogging (i.e. have CRYPTO_TFM_REQ_MAY_BACKLOG set), will hang. > > Such an example is dm-crypt. The current patch solves this issue by > > setting a threshold after which caam_jr_enqueue() returns -EBUSY, but > > since the HW job ring isn't actually full, the job is enqueued. > > > The commit message should mention that *both* number of tfms / Job Ring > *and* the number of available Job Ring slots (configured by > CRYPTO_DEV_FSL_CAAM_RINGSIZE) is being limited by JOBR_THRESH: > tfms / Job Ring < JOBR_THRESH > available (free) Job Ring slots >= JOBR_THRESH [AP] I'm not sure that we need to confuse the user even more; setting the # of slots is anyhow not so obvious. On the other hand, we have a self-imposed limitation for the # of slots (power of two). I'd like to run some benchmarks and see if the cpu load is affected that much when giving up this constraint. If so, then we can go up to 1023 slots per JR. > > Shouldn't caam_jr_enqueue() from key_gen.c be changed too? > Generating a split key is supposed to be done on behalf of the underlying > tfm, thus the MAY_BACKLOG flag should be checked here too. [AP] I'd actually like to fail the tunnel creation in case split key fails. Either way, the code needs to be adjusted. > > > Signed-off-by: Alexandru Porosanu > > Tested-by: Catalin Vasile > > --- > > drivers/crypto/caam/caamalg.c | 88 ++++++++++++++++-- > > drivers/crypto/caam/caamhash.c | 101 +++++++++++++++++++-- > > drivers/crypto/caam/intern.h | 7 ++ > > drivers/crypto/caam/jr.c | 196 > +++++++++++++++++++++++++++++++++-------- > > drivers/crypto/caam/jr.h | 5 ++ > > 5 files changed, 343 insertions(+), 54 deletions(-) > > > > diff --git a/drivers/crypto/caam/caamalg.c > > b/drivers/crypto/caam/caamalg.c index ea8189f..62bce17 100644 > > --- a/drivers/crypto/caam/caamalg.c > > +++ b/drivers/crypto/caam/caamalg.c > > @@ -1921,6 +1921,9 @@ static void aead_encrypt_done(struct device > > *jrdev, u32 *desc, u32 err, > > > > edesc = container_of(desc, struct aead_edesc, hw_desc[0]); > > > > + if (err == -EINPROGRESS) > > + goto out_bklogged; > > Checking that err is -EINPROGRESS should be the first thing to do in *_done > callbacks. > > > + > > if (err) > > caam_jr_strstatus(jrdev, err); > > > > @@ -1928,6 +1931,7 @@ static void aead_encrypt_done(struct device > > *jrdev, u32 *desc, u32 err, > > > > kfree(edesc); > > > > +out_bklogged: > > aead_request_complete(req, err); > > } > > > > @@ -1943,6 +1947,9 @@ static void aead_decrypt_done(struct device > > *jrdev, u32 *desc, u32 err, > > > > edesc = container_of(desc, struct aead_edesc, hw_desc[0]); > > > > + if (err == -EINPROGRESS) > > + goto out_bklogged; > > + > > if (err) > > caam_jr_strstatus(jrdev, err); > > > > @@ -1956,6 +1963,7 @@ static void aead_decrypt_done(struct device > > *jrdev, u32 *desc, u32 err, > > > > kfree(edesc); > > > > +out_bklogged: > > aead_request_complete(req, err); > > } > > > > @@ -1974,6 +1982,9 @@ static void ablkcipher_encrypt_done(struct > device *jrdev, u32 *desc, u32 err, > > edesc = (struct ablkcipher_edesc *)((char *)desc - > > offsetof(struct ablkcipher_edesc, hw_desc)); > > > > + if (err == -EINPROGRESS) > > + goto out_bklogged; > > + > > if (err) > > caam_jr_strstatus(jrdev, err); > > > > @@ -1989,6 +2000,7 @@ static void ablkcipher_encrypt_done(struct > device *jrdev, u32 *desc, u32 err, > > ablkcipher_unmap(jrdev, edesc, req); > > kfree(edesc); > > > > +out_bklogged: > > ablkcipher_request_complete(req, err); } > > > > @@ -2006,6 +2018,10 @@ static void ablkcipher_decrypt_done(struct > > device *jrdev, u32 *desc, u32 err, > > > > edesc = (struct ablkcipher_edesc *)((char *)desc - > > offsetof(struct ablkcipher_edesc, hw_desc)); > > + > > + if (err == -EINPROGRESS) > > + goto out_bklogged; > > + > > if (err) > > caam_jr_strstatus(jrdev, err); > > > > @@ -2021,6 +2037,7 @@ static void ablkcipher_decrypt_done(struct > device *jrdev, u32 *desc, u32 err, > > ablkcipher_unmap(jrdev, edesc, req); > > kfree(edesc); > > > > +out_bklogged: > > ablkcipher_request_complete(req, err); } > > > > @@ -2394,7 +2411,15 @@ static int gcm_encrypt(struct aead_request > > *req) #endif > > > > desc = edesc->hw_desc; > > - ret = caam_jr_enqueue(jrdev, desc, aead_encrypt_done, req); > > + if (req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG) { > > + ret = caam_jr_enqueue_bklog(jrdev, desc, > aead_encrypt_done, > > + req); > > + if (ret == -EBUSY) > > + return ret; > > + } else { > > + ret = caam_jr_enqueue(jrdev, desc, aead_encrypt_done, > req); > > + } > > + > > if (!ret) { > > ret = -EINPROGRESS; > > } else { > > @@ -2438,7 +2463,15 @@ static int aead_encrypt(struct aead_request > > *req) #endif > > > > desc = edesc->hw_desc; > > - ret = caam_jr_enqueue(jrdev, desc, aead_encrypt_done, req); > > + if (req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG) { > > + ret = caam_jr_enqueue_bklog(jrdev, desc, > aead_encrypt_done, > > + req); > > + if (ret == -EBUSY) > > + return ret; > > + } else { > > + ret = caam_jr_enqueue(jrdev, desc, aead_encrypt_done, > req); > > + } > > + > > if (!ret) { > > ret = -EINPROGRESS; > > } else { > > @@ -2473,7 +2506,15 @@ static int gcm_decrypt(struct aead_request > > *req) #endif > > > > desc = edesc->hw_desc; > > - ret = caam_jr_enqueue(jrdev, desc, aead_decrypt_done, req); > > + if (req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG) { > > + ret = caam_jr_enqueue_bklog(jrdev, desc, > aead_decrypt_done, > > + req); > > + if (ret == -EBUSY) > > + return ret; > > + } else { > > + ret = caam_jr_enqueue(jrdev, desc, aead_decrypt_done, > req); > > + } > > + > > if (!ret) { > > ret = -EINPROGRESS; > > } else { > > @@ -2523,7 +2564,15 @@ static int aead_decrypt(struct aead_request > > *req) #endif > > > > desc = edesc->hw_desc; > > - ret = caam_jr_enqueue(jrdev, desc, aead_decrypt_done, req); > > + if (req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG) { > > + ret = caam_jr_enqueue_bklog(jrdev, desc, > aead_decrypt_done, > > + req); > > + if (ret == -EBUSY) > > + return ret; > > + } else { > > + ret = caam_jr_enqueue(jrdev, desc, aead_decrypt_done, > req); > > + } > > + > > if (!ret) { > > ret = -EINPROGRESS; > > } else { > > @@ -2672,7 +2721,15 @@ static int ablkcipher_encrypt(struct > ablkcipher_request *req) > > desc_bytes(edesc->hw_desc), 1); #endif > > desc = edesc->hw_desc; > > - ret = caam_jr_enqueue(jrdev, desc, ablkcipher_encrypt_done, req); > > + if (req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG) { > > + ret = caam_jr_enqueue_bklog(jrdev, desc, > > + ablkcipher_encrypt_done, req); > > + if (ret == -EBUSY) > > + return ret; > > + } else { > > + ret = caam_jr_enqueue(jrdev, desc, > ablkcipher_encrypt_done, > > + req); > > + } > > > > if (!ret) { > > ret = -EINPROGRESS; > > @@ -2710,7 +2767,16 @@ static int ablkcipher_decrypt(struct > ablkcipher_request *req) > > desc_bytes(edesc->hw_desc), 1); #endif > > > > - ret = caam_jr_enqueue(jrdev, desc, ablkcipher_decrypt_done, req); > > + if (req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG) { > > + ret = caam_jr_enqueue_bklog(jrdev, desc, > > + ablkcipher_decrypt_done, req); > > + if (ret == -EBUSY) > > + return ret; > > + } else { > > + ret = caam_jr_enqueue(jrdev, desc, > ablkcipher_decrypt_done, > > + req); > > + } > > + > > if (!ret) { > > ret = -EINPROGRESS; > > } else { > > @@ -2851,7 +2917,15 @@ static int ablkcipher_givencrypt(struct > skcipher_givcrypt_request *creq) > > desc_bytes(edesc->hw_desc), 1); #endif > > desc = edesc->hw_desc; > > - ret = caam_jr_enqueue(jrdev, desc, ablkcipher_encrypt_done, req); > > + if (req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG) { > > + ret = caam_jr_enqueue_bklog(jrdev, desc, > > + ablkcipher_encrypt_done, req); > > + if (ret == -EBUSY) > > + return ret; > > + } else { > > + ret = caam_jr_enqueue(jrdev, desc, > ablkcipher_encrypt_done, > > + req); > > + } > > > > if (!ret) { > > ret = -EINPROGRESS; > > diff --git a/drivers/crypto/caam/caamhash.c > > b/drivers/crypto/caam/caamhash.c index 5845d4a..910a350 100644 > > --- a/drivers/crypto/caam/caamhash.c > > +++ b/drivers/crypto/caam/caamhash.c > > @@ -650,6 +650,10 @@ static void ahash_done(struct device *jrdev, u32 > > *desc, u32 err, > > > > edesc = (struct ahash_edesc *)((char *)desc - > > offsetof(struct ahash_edesc, hw_desc)); > > + > > + if (err == -EINPROGRESS) > > + goto out_bklogged; > > + > > if (err) > > caam_jr_strstatus(jrdev, err); > > > > @@ -666,6 +670,7 @@ static void ahash_done(struct device *jrdev, u32 > *desc, u32 err, > > digestsize, 1); > > #endif > > > > +out_bklogged: > > req->base.complete(&req->base, err); } > > > > @@ -685,6 +690,10 @@ static void ahash_done_bi(struct device *jrdev, > > u32 *desc, u32 err, > > > > edesc = (struct ahash_edesc *)((char *)desc - > > offsetof(struct ahash_edesc, hw_desc)); > > + > > + if (err == -EINPROGRESS) > > + goto out_bklogged; > > + > > if (err) > > caam_jr_strstatus(jrdev, err); > > > > @@ -701,6 +710,7 @@ static void ahash_done_bi(struct device *jrdev, u32 > *desc, u32 err, > > digestsize, 1); > > #endif > > > > +out_bklogged: > > req->base.complete(&req->base, err); } > > > > @@ -720,6 +730,10 @@ static void ahash_done_ctx_src(struct device > > *jrdev, u32 *desc, u32 err, > > > > edesc = (struct ahash_edesc *)((char *)desc - > > offsetof(struct ahash_edesc, hw_desc)); > > + > > + if (err == -EINPROGRESS) > > + goto out_bklogged; > > + > > if (err) > > caam_jr_strstatus(jrdev, err); > > > > @@ -736,6 +750,7 @@ static void ahash_done_ctx_src(struct device > *jrdev, u32 *desc, u32 err, > > digestsize, 1); > > #endif > > > > +out_bklogged: > > req->base.complete(&req->base, err); } > > > > @@ -755,6 +770,10 @@ static void ahash_done_ctx_dst(struct device > > *jrdev, u32 *desc, u32 err, > > > > edesc = (struct ahash_edesc *)((char *)desc - > > offsetof(struct ahash_edesc, hw_desc)); > > + > > + if (err == -EINPROGRESS) > > + goto out_bklogged; > > + > > if (err) > > caam_jr_strstatus(jrdev, err); > > > > @@ -771,6 +790,7 @@ static void ahash_done_ctx_dst(struct device > *jrdev, u32 *desc, u32 err, > > digestsize, 1); > > #endif > > > > +out_bklogged: > > req->base.complete(&req->base, err); } > > > > @@ -876,7 +896,15 @@ static int ahash_update_ctx(struct ahash_request > *req) > > desc_bytes(desc), 1); > > #endif > > > > - ret = caam_jr_enqueue(jrdev, desc, ahash_done_bi, req); > > + if (req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG) { > > + ret = caam_jr_enqueue_bklog(jrdev, desc, > ahash_done_bi, > > + req); > > + if (ret == -EBUSY) > > + return ret; > > + } else { > > + ret = caam_jr_enqueue(jrdev, desc, ahash_done_bi, > req); > > + } > > + > > if (!ret) { > > ret = -EINPROGRESS; > > } else { > > @@ -973,7 +1001,15 @@ static int ahash_final_ctx(struct ahash_request > *req) > > DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc), > 1); > > #endif > > > > - ret = caam_jr_enqueue(jrdev, desc, ahash_done_ctx_src, req); > > + if (req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG) { > > + ret = caam_jr_enqueue_bklog(jrdev, desc, > ahash_done_ctx_src, > > + req); > > + if (ret == -EBUSY) > > + return ret; > > + } else { > > + ret = caam_jr_enqueue(jrdev, desc, ahash_done_ctx_src, > req); > > + } > > + > > if (!ret) { > > ret = -EINPROGRESS; > > } else { > > @@ -1065,7 +1101,15 @@ static int ahash_finup_ctx(struct ahash_request > *req) > > DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc), > 1); > > #endif > > > > - ret = caam_jr_enqueue(jrdev, desc, ahash_done_ctx_src, req); > > + if (req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG) { > > + ret = caam_jr_enqueue_bklog(jrdev, desc, > ahash_done_ctx_src, > > + req); > > + if (ret == -EBUSY) > > + return ret; > > + } else { > > + ret = caam_jr_enqueue(jrdev, desc, ahash_done_ctx_src, > req); > > + } > > + > > if (!ret) { > > ret = -EINPROGRESS; > > } else { > > @@ -1145,7 +1189,14 @@ static int ahash_digest(struct ahash_request > *req) > > DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc), > 1); > > #endif > > > > - ret = caam_jr_enqueue(jrdev, desc, ahash_done, req); > > + if (req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG) { > > + ret = caam_jr_enqueue_bklog(jrdev, desc, ahash_done, > req); > > + if (ret == -EBUSY) > > + return ret; > > + } else { > > + ret = caam_jr_enqueue(jrdev, desc, ahash_done, req); > > + } > > + > > if (!ret) { > > ret = -EINPROGRESS; > > } else { > > @@ -1207,7 +1258,14 @@ static int ahash_final_no_ctx(struct > ahash_request *req) > > DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc), > 1); > > #endif > > > > - ret = caam_jr_enqueue(jrdev, desc, ahash_done, req); > > + if (req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG) { > > + ret = caam_jr_enqueue_bklog(jrdev, desc, ahash_done, > req); > > + if (ret == -EBUSY) > > + return ret; > > + } else { > > + ret = caam_jr_enqueue(jrdev, desc, ahash_done, req); > > + } > > + > > if (!ret) { > > ret = -EINPROGRESS; > > } else { > > @@ -1308,7 +1366,16 @@ static int ahash_update_no_ctx(struct > ahash_request *req) > > desc_bytes(desc), 1); > > #endif > > > > - ret = caam_jr_enqueue(jrdev, desc, ahash_done_ctx_dst, > req); > > + if (req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG) { > > + ret = caam_jr_enqueue_bklog(jrdev, desc, > > + ahash_done_ctx_dst, req); > > + if (ret == -EBUSY) > > + return ret; > > + } else { > > + ret = caam_jr_enqueue(jrdev, desc, > ahash_done_ctx_dst, > > + req); > > + } > > + > > if (!ret) { > > ret = -EINPROGRESS; > > state->update = ahash_update_ctx; > > @@ -1411,7 +1478,15 @@ static int ahash_finup_no_ctx(struct > ahash_request *req) > > DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc), > 1); > > #endif > > > > - ret = caam_jr_enqueue(jrdev, desc, ahash_done, req); > > + if (req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG) { > > + ret = caam_jr_enqueue_bklog(jrdev, desc, ahash_done, > > + req); > > + if (ret == -EBUSY) > > + return ret; > > + } else { > > + ret = caam_jr_enqueue(jrdev, desc, ahash_done, req); > > + } > > + > > if (!ret) { > > ret = -EINPROGRESS; > > } else { > > @@ -1514,8 +1589,16 @@ static int ahash_update_first(struct > ahash_request *req) > > desc_bytes(desc), 1); > > #endif > > > > - ret = caam_jr_enqueue(jrdev, desc, ahash_done_ctx_dst, > > - req); > > + if (req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG) { > > + ret = caam_jr_enqueue_bklog(jrdev, desc, > > + ahash_done_ctx_dst, req); > > + if (ret == -EBUSY) > > + return ret; > > + } else { > > + ret = caam_jr_enqueue(jrdev, desc, > ahash_done_ctx_dst, > > + req); > > + } > > + > > if (!ret) { > > ret = -EINPROGRESS; > > state->update = ahash_update_ctx; > > diff --git a/drivers/crypto/caam/intern.h > > b/drivers/crypto/caam/intern.h index e2bcacc..aa4e257 100644 > > --- a/drivers/crypto/caam/intern.h > > +++ b/drivers/crypto/caam/intern.h > > @@ -11,6 +11,12 @@ > > > > /* Currently comes from Kconfig param as a ^2 (driver-required) */ > > #define JOBR_DEPTH (1 << CONFIG_CRYPTO_DEV_FSL_CAAM_RINGSIZE) > > +/* > > + * If the user tries to enqueue a job and the number of slots > > +available > > + * is less than this value, then the job will be backlogged (if the > > +user > > + * allows for it) or it will be dropped. > > + */ > > +#define JOBR_THRESH (JOBR_DEPTH / 2 - 1) > > > > /* Kconfig params for interrupt coalescing if selected (else zero) */ > > #ifdef CONFIG_CRYPTO_DEV_FSL_CAAM_INTC @@ -33,6 +39,7 @@ struct > > caam_jrentry_info { > > u32 *desc_addr_virt; /* Stored virt addr for postprocessing */ > > dma_addr_t desc_addr_dma; /* Stored bus addr for done matching > */ > > u32 desc_size; /* Stored size for postprocessing, header derived */ > > + bool is_backlogged; /* True if the request has been backlogged */ > > }; > > > > /* Private sub-storage for a single JobR */ diff --git > > a/drivers/crypto/caam/jr.c b/drivers/crypto/caam/jr.c index > > 5ef4be2..49790e1 100644 > > --- a/drivers/crypto/caam/jr.c > > +++ b/drivers/crypto/caam/jr.c > > @@ -168,6 +168,7 @@ static void caam_jr_dequeue(unsigned long devarg) > > void (*usercall)(struct device *dev, u32 *desc, u32 status, void *arg); > > u32 *userdesc, userstatus; > > void *userarg; > > + bool is_backlogged; > > > > while (rd_reg32(&jrp->rregs->outring_used)) { > > > > @@ -201,6 +202,9 @@ static void caam_jr_dequeue(unsigned long devarg) > > userarg = jrp->entinfo[sw_idx].cbkarg; > > userdesc = jrp->entinfo[sw_idx].desc_addr_virt; > > userstatus = jrp->outring[hw_idx].jrstatus; > > + is_backlogged = jrp->entinfo[sw_idx].is_backlogged; > > + /* Reset backlogging status here */ > > + jrp->entinfo[sw_idx].is_backlogged = false; > > > > /* > > * Make sure all information from the job has been obtained > @@ > > -231,6 +235,20 @@ static void caam_jr_dequeue(unsigned long devarg) > > > > spin_unlock(&jrp->outlock); > > > > + if (is_backlogged) > > + /* > > + * For backlogged requests, the user callback needs > to > > + * be called twice: once when starting to process it > > + * (with a status of -EINPROGRESS and once when it's > ^ paranthesis not closed > > > + * done. Since SEC cheats by enqueuing the request > in > > + * its HW ring but returning -EBUSY, the time when > the > > + * request's processing has started is not known. > > + * Thus notify here the user. The second call is on the > > + * normal path (i.e. the one that is called even for > > + * non-backlogged requests). > > + */ > > + usercall(dev, userdesc, -EINPROGRESS, userarg); > > + > > /* Finally, execute user's callback */ > > usercall(dev, userdesc, userstatus, userarg); > > } > > @@ -261,6 +279,15 @@ struct device *caam_jr_alloc(void) > > > > list_for_each_entry(jrpriv, &driver_data.jr_list, list_node) { > > tfm_cnt = atomic_read(&jrpriv->tfm_count); > > + > > + /* > > + * Don't allow more than JOBR_THRES jobs on this JR. If more > > What's being limited here is not the number of jobs, but the number of tfms. > > > + * are allowed, then backlogging API contract won't work > (each > > + * "backloggable" tfm must allow for at least 1 enqueue. > > + */ > > + if (tfm_cnt == JOBR_THRESH) > > + continue; > > + > > if (tfm_cnt < min_tfm_cnt) { > > min_tfm_cnt = tfm_cnt; > > min_jrpriv = jrpriv; > > @@ -292,6 +319,80 @@ void caam_jr_free(struct device *rdev) } > > EXPORT_SYMBOL(caam_jr_free); > > > > +static inline int __caam_jr_enqueue(struct caam_drv_private_jr *jrp, u32 > *desc, > > + int desc_size, dma_addr_t desc_dma, > > + void (*cbk)(struct device *dev, u32 *desc, > > + u32 status, void *areq), > > + void *areq, > > + bool can_be_backlogged) > > +{ > > + int head, tail; > > + struct caam_jrentry_info *head_entry; > > + int ret = 0, hw_slots, sw_slots; > > + > > + spin_lock_bh(&jrp->inplock); > > + > > + head = jrp->head; > > + tail = ACCESS_ONCE(jrp->tail); > > + > > + head_entry = &jrp->entinfo[head]; > > + > > + hw_slots = rd_reg32(&jrp->rregs->inpring_avail); > > + sw_slots = CIRC_SPACE(head, tail, JOBR_DEPTH); > > + > > + if (hw_slots <= JOBR_THRESH || sw_slots <= JOBR_THRESH) { > > + /* > > + * The state below can be reached in three cases: > > + * 1) A badly behaved backlogging user doesn't back off when > > + * told so by the -EBUSY return code > > + * 2) More than JOBR_THRESH backlogging users requests > > AFAICS, this case is no longer possible, since the number of "users" > (tfms) is being limited to JOBR_THRESH in caam_jr_alloc(). > > > + * 3) Due to the high system load, the entries reserved for > the > > + * backlogging users are being filled (slowly) in between > > + * the successive calls to the user callback (the first one > > + * with -EINPROGRESS and the 2nd one with the real result. > > + * The code below is a last-resort measure which will DROP > > + * any request if there is physically no more space. This will > > + * lead to data-loss for disk-related users. > ^^^^^^^^^^^^^^^^^^^^^^^^^^ > This should be enough to reject the solution. > It's way too easy / probable to start losing data, when compared with a SW- > only queue that is bounded only by system memory. > > > + */ > > + if (!hw_slots || !sw_slots) { > > + ret = -EIO; > > + goto out_unlock; > > + } > > + > > + ret = -EBUSY; > > + if (!can_be_backlogged) > > + goto out_unlock; > > + > > + head_entry->is_backlogged = true; > > + } > > + > > + head_entry->desc_addr_virt = desc; > > + head_entry->desc_size = desc_size; > > + head_entry->callbk = (void *)cbk; > > + head_entry->cbkarg = areq; > > + head_entry->desc_addr_dma = desc_dma; > > + > > + jrp->inpring[jrp->inp_ring_write_index] = desc_dma; > > + > > + /* > > + * Guarantee that the descriptor's DMA address has been written to > > + * the next slot in the ring before the write index is updated, since > > + * other cores may update this index independently. > > + */ > > + smp_wmb(); > > + > > + jrp->inp_ring_write_index = (jrp->inp_ring_write_index + 1) & > > + (JOBR_DEPTH - 1); > > + jrp->head = (head + 1) & (JOBR_DEPTH - 1); > > + > > + wr_reg32(&jrp->rregs->inpring_jobadd, 1); > > + > > +out_unlock: > > + spin_unlock_bh(&jrp->inplock); > > + > > + return ret; > > +} > > + > > /** > > * caam_jr_enqueue() - Enqueue a job descriptor head. Returns 0 if OK, > > * -EBUSY if the queue is full, -EIO if it cannot map the caller's @@ > > -326,8 +427,7 @@ int caam_jr_enqueue(struct device *dev, u32 *desc, > > void *areq) > > { > > struct caam_drv_private_jr *jrp = dev_get_drvdata(dev); > > - struct caam_jrentry_info *head_entry; > > - int head, tail, desc_size; > > + int desc_size, ret; > > dma_addr_t desc_dma; > > > > desc_size = (*desc & HDR_JD_LENGTH_MASK) * sizeof(u32); @@ - > 337,51 > > +437,71 @@ int caam_jr_enqueue(struct device *dev, u32 *desc, > > return -EIO; > > } > > > > - spin_lock_bh(&jrp->inplock); > > - > > - head = jrp->head; > > - tail = ACCESS_ONCE(jrp->tail); > > - > > - if (!rd_reg32(&jrp->rregs->inpring_avail) || > > - CIRC_SPACE(head, tail, JOBR_DEPTH) <= 0) { > > - spin_unlock_bh(&jrp->inplock); > > + ret = __caam_jr_enqueue(jrp, desc, desc_size, desc_dma, cbk, areq, > > + false); > > + if (unlikely(ret)) > > dma_unmap_single(dev, desc_dma, desc_size, > DMA_TO_DEVICE); > > - return -EBUSY; > > - } > > > > - head_entry = &jrp->entinfo[head]; > > - head_entry->desc_addr_virt = desc; > > - head_entry->desc_size = desc_size; > > - head_entry->callbk = (void *)cbk; > > - head_entry->cbkarg = areq; > > - head_entry->desc_addr_dma = desc_dma; > > - > > - jrp->inpring[jrp->inp_ring_write_index] = desc_dma; > > + return 0; > > +} > > +EXPORT_SYMBOL(caam_jr_enqueue); > > > > - /* > > - * Guarantee that the descriptor's DMA address has been written to > > - * the next slot in the ring before the write index is updated, since > > - * other cores may update this index independently. > > - */ > > - smp_wmb(); > > +/** > > + * caam_jr_enqueue_bklog() - Enqueue a job descriptor head, returns 0 > > +if OK, or > > + * -EBUSY if the number of available entries in the Job Ring is less > > + * than the threshold configured through JOBR_THRESH, and -EIO if it > > +cannot map > > + * the caller's descriptor or if there is really no more space in the > > +hardware > > + * job ring. > > + * @dev: device of the job ring to be used. This device should have > > + * been assigned prior by caam_jr_register(). > > + * @desc: points to a job descriptor that execute our request. All > > + * descriptors (and all referenced data) must be in a DMAable > > + * region, and all data references must be physical addresses > > + * accessible to CAAM (i.e. within a PAMU window granted > > + * to it). > > + * @cbk: pointer to a callback function to be invoked upon completion > > + * of this request. This has the form: > > + * callback(struct device *dev, u32 *desc, u32 stat, void *arg) > > + * where: > > + * @dev: contains the job ring device that processed this > > + * response. > > + * @desc: descriptor that initiated the request, same as > > + * "desc" being argued to caam_jr_enqueue(). > > + * @status: untranslated status received from CAAM. See the > > + * reference manual for a detailed description of > > + * error meaning, or see the JRSTA definitions in the > > + * register header file > > + * @areq: optional pointer to an argument passed with the > > + * original request > > + * @areq: optional pointer to a user argument for use at callback > > + * time. > > + **/ > > +int caam_jr_enqueue_bklog(struct device *dev, u32 *desc, > > + void (*cbk)(struct device *dev, u32 *desc, > > + u32 status, void *areq), > > + void *areq) > > +{ > > + struct caam_drv_private_jr *jrp = dev_get_drvdata(dev); > > + int desc_size, ret; > > + dma_addr_t desc_dma; > > > > - jrp->inp_ring_write_index = (jrp->inp_ring_write_index + 1) & > > - (JOBR_DEPTH - 1); > > - jrp->head = (head + 1) & (JOBR_DEPTH - 1); > > > > - /* > > - * Ensure that all job information has been written before > > - * notifying CAAM that a new job was added to the input ring. > > - */ > > - wmb(); > > + desc_size = (*desc & HDR_JD_LENGTH_MASK) * sizeof(u32); > > + desc_dma = dma_map_single(dev, desc, desc_size, > DMA_TO_DEVICE); > > + if (dma_mapping_error(dev, desc_dma)) { > > + dev_err(dev, "caam_jr_enqueue(): can't map jobdesc\n"); > > + return -EIO; > > + } > > > > - wr_reg32(&jrp->rregs->inpring_jobadd, 1); > > + ret = __caam_jr_enqueue(jrp, desc, desc_size, desc_dma, cbk, areq, > > + true); > > + if (unlikely(ret && (ret != -EBUSY))) > > + dma_unmap_single(dev, desc_dma, desc_size, > DMA_TO_DEVICE); > > > > - spin_unlock_bh(&jrp->inplock); > > + return ret; > > > > - return 0; > > } > > -EXPORT_SYMBOL(caam_jr_enqueue); > > +EXPORT_SYMBOL(caam_jr_enqueue_bklog); > > > > /* > > * Init JobR independent of platform property detection diff --git > > a/drivers/crypto/caam/jr.h b/drivers/crypto/caam/jr.h index > > 97113a6..21558df 100644 > > --- a/drivers/crypto/caam/jr.h > > +++ b/drivers/crypto/caam/jr.h > > @@ -15,4 +15,9 @@ int caam_jr_enqueue(struct device *dev, u32 *desc, > > void *areq), > > void *areq); > > > > +int caam_jr_enqueue_bklog(struct device *dev, u32 *desc, > > + void (*cbk)(struct device *dev, u32 *desc, u32 > status, > > + void *areq), > > + void *areq); > > + > > #endif /* JR_H */ > > > > Regards, > Horia BR, Alex P.