From patchwork Thu Apr 9 11:00:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11481573 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AE34C112C for ; Thu, 9 Apr 2020 11:01:24 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 94F9D20771 for ; Thu, 9 Apr 2020 11:01:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 94F9D20771 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2777E89015; Thu, 9 Apr 2020 11:01:19 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id 36D886E0FE; Thu, 9 Apr 2020 11:01:16 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from build.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 20849840-1500050 for multiple; Thu, 09 Apr 2020 12:01:02 +0100 From: Chris Wilson To: dri-devel@lists.freedesktop.org Subject: [PATCH 1/3] dma-buf: Prettify typecasts for dma-fence-chain Date: Thu, 9 Apr 2020 12:00:59 +0100 Message-Id: <20200409110101.18400-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mika Kuoppala , intel-gfx@lists.freedesktop.org, Chris Wilson Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Inside dma-fence-chain, we use a cmpxchg on an RCU-protected pointer. To avoid the sparse warning for using the RCU pointer directly, we have to cast away the __rcu annotation. However, we don't need to use void* everywhere and can stick to the dma_fence*. Signed-off-by: Chris Wilson Reviewed-by: Mika Kuoppala --- drivers/dma-buf/dma-fence-chain.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/dma-buf/dma-fence-chain.c b/drivers/dma-buf/dma-fence-chain.c index 44a741677d25..3d123502ff12 100644 --- a/drivers/dma-buf/dma-fence-chain.c +++ b/drivers/dma-buf/dma-fence-chain.c @@ -62,7 +62,8 @@ struct dma_fence *dma_fence_chain_walk(struct dma_fence *fence) replacement = NULL; } - tmp = cmpxchg((void **)&chain->prev, (void *)prev, (void *)replacement); + tmp = cmpxchg((struct dma_fence __force **)&chain->prev, + prev, replacement); if (tmp == prev) dma_fence_put(tmp); else From patchwork Thu Apr 9 11:01:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11481579 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 14A0F112C for ; Thu, 9 Apr 2020 11:01:30 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EF94F20771 for ; Thu, 9 Apr 2020 11:01:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EF94F20771 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 33B616E0FE; Thu, 9 Apr 2020 11:01:24 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id E805E6E0FE; Thu, 9 Apr 2020 11:01:21 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from build.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 20849841-1500050 for multiple; Thu, 09 Apr 2020 12:01:03 +0100 From: Chris Wilson To: dri-devel@lists.freedesktop.org Subject: [PATCH 2/3] dma-buf: Report signaled links inside dma-fence-chain Date: Thu, 9 Apr 2020 12:01:00 +0100 Message-Id: <20200409110101.18400-2-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200409110101.18400-1-chris@chris-wilson.co.uk> References: <20200409110101.18400-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org, Venkata Sandeep Dhanalakota , Chris Wilson Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Whenever we walk along the dma-fence-chain, we prune signaled links to keep the chain nice and tidy. This leads to situations where we can prune a link and report the earlier fence as the target seqno -- violating our own consistency checks that the seqno is not more advanced than the last element in a dma-fence-chain. Report a NULL fence and success if the seqno has already been signaled. Signed-off-by: Chris Wilson Tested-by: Venkata Sandeep Dhanalakota Reviewed-by: Venkata Sandeep Dhanalakota --- drivers/dma-buf/dma-fence-chain.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/dma-buf/dma-fence-chain.c b/drivers/dma-buf/dma-fence-chain.c index 3d123502ff12..c435bbba851c 100644 --- a/drivers/dma-buf/dma-fence-chain.c +++ b/drivers/dma-buf/dma-fence-chain.c @@ -99,6 +99,12 @@ int dma_fence_chain_find_seqno(struct dma_fence **pfence, uint64_t seqno) return -EINVAL; dma_fence_chain_for_each(*pfence, &chain->base) { + if ((*pfence)->seqno < seqno) { /* already signaled */ + dma_fence_put(*pfence); + *pfence = NULL; + break; + } + if ((*pfence)->context != chain->base.context || to_dma_fence_chain(*pfence)->prev_seqno < seqno) break; @@ -222,6 +228,7 @@ EXPORT_SYMBOL(dma_fence_chain_ops); * @chain: the chain node to initialize * @prev: the previous fence * @fence: the current fence + * @seqno: the sequence number (syncpt) of the fence within the chain * * Initialize a new chain node and either start a new chain or add the node to * the existing chain of the previous fence. From patchwork Thu Apr 9 11:01:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11481575 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 18E6E112C for ; Thu, 9 Apr 2020 11:01:27 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F3F0820771 for ; Thu, 9 Apr 2020 11:01:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F3F0820771 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2A5F289FF9; Thu, 9 Apr 2020 11:01:21 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id DBBCF6E0FF; Thu, 9 Apr 2020 11:01:17 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from build.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 20849844-1500050 for multiple; Thu, 09 Apr 2020 12:01:03 +0100 From: Chris Wilson To: dri-devel@lists.freedesktop.org Subject: [PATCH 3/3] dma-buf: Exercise dma-fence-chain under selftests Date: Thu, 9 Apr 2020 12:01:01 +0100 Message-Id: <20200409110101.18400-3-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200409110101.18400-1-chris@chris-wilson.co.uk> References: <20200409110101.18400-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org, Venkata Sandeep Dhanalakota , Chris Wilson Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" A few very simple testcases to exercise the dma-fence-chain API. Signed-off-by: Chris Wilson Reviewed-by: Venkata Sandeep Dhanalakota --- drivers/dma-buf/Makefile | 3 +- drivers/dma-buf/selftests.h | 1 + drivers/dma-buf/st-dma-fence-chain.c | 713 +++++++++++++++++++++++++++ 3 files changed, 716 insertions(+), 1 deletion(-) create mode 100644 drivers/dma-buf/st-dma-fence-chain.c diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile index 9c190026bfab..995e05f609ff 100644 --- a/drivers/dma-buf/Makefile +++ b/drivers/dma-buf/Makefile @@ -9,6 +9,7 @@ obj-$(CONFIG_UDMABUF) += udmabuf.o dmabuf_selftests-y := \ selftest.o \ - st-dma-fence.o + st-dma-fence.o \ + st-dma-fence-chain.o obj-$(CONFIG_DMABUF_SELFTESTS) += dmabuf_selftests.o diff --git a/drivers/dma-buf/selftests.h b/drivers/dma-buf/selftests.h index 5320386f02e5..55918ef9adab 100644 --- a/drivers/dma-buf/selftests.h +++ b/drivers/dma-buf/selftests.h @@ -11,3 +11,4 @@ */ selftest(sanitycheck, __sanitycheck__) /* keep first (igt selfcheck) */ selftest(dma_fence, dma_fence) +selftest(dma_fence_chain, dma_fence_chain) diff --git a/drivers/dma-buf/st-dma-fence-chain.c b/drivers/dma-buf/st-dma-fence-chain.c new file mode 100644 index 000000000000..bd08ba67b03b --- /dev/null +++ b/drivers/dma-buf/st-dma-fence-chain.c @@ -0,0 +1,713 @@ +// SPDX-License-Identifier: MIT + +/* + * Copyright © 2019 Intel Corporation + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "selftest.h" + +static struct kmem_cache *slab_fences; + +static inline struct mock_fence { + struct dma_fence base; + spinlock_t lock; +} *to_mock_fence(struct dma_fence *f) { + return container_of(f, struct mock_fence, base); +} + +static const char *mock_name(struct dma_fence *f) +{ + return "mock"; +} + +static void mock_fence_release(struct dma_fence *f) +{ + kmem_cache_free(slab_fences, to_mock_fence(f)); +} + +static const struct dma_fence_ops mock_ops = { + .get_driver_name = mock_name, + .get_timeline_name = mock_name, + .release = mock_fence_release, +}; + +static struct dma_fence *mock_fence(void) +{ + struct mock_fence *f; + + f = kmem_cache_alloc(slab_fences, GFP_KERNEL); + if (!f) + return NULL; + + spin_lock_init(&f->lock); + dma_fence_init(&f->base, &mock_ops, &f->lock, 0, 0); + + return &f->base; +} + +static inline struct mock_chain { + struct dma_fence_chain base; +} *to_mock_chain(struct dma_fence *f) { + return container_of(f, struct mock_chain, base.base); +} + +static struct dma_fence *mock_chain(struct dma_fence *prev, + struct dma_fence *fence, + u64 seqno) +{ + struct mock_chain *f; + + f = kmalloc(sizeof(*f), GFP_KERNEL); + if (!f) + return NULL; + + dma_fence_chain_init(&f->base, + dma_fence_get(prev), + dma_fence_get(fence), + seqno); + + return &f->base.base; +} + +static int sanitycheck(void *arg) +{ + struct dma_fence *f, *chain; + int err = 0; + + f = mock_fence(); + if (!f) + return -ENOMEM; + + chain = mock_chain(NULL, f, 1); + if (!chain) + err = -ENOMEM; + + dma_fence_signal(f); + dma_fence_put(f); + + dma_fence_put(chain); + + return err; +} + +struct fence_chains { + unsigned int chain_length; + struct dma_fence **fences; + struct dma_fence **chains; + + struct dma_fence *tail; +}; + +static uint64_t seqno_inc(unsigned int i) +{ + return i + 1; +} + +static int fence_chains_init(struct fence_chains *fc, unsigned int count, + uint64_t (*seqno_fn)(unsigned int)) +{ + unsigned int i; + int err = 0; + + fc->chains = kvmalloc_array(count, sizeof(*fc->chains), + GFP_KERNEL | __GFP_ZERO); + if (!fc->chains) + return -ENOMEM; + + fc->fences = kvmalloc_array(count, sizeof(*fc->fences), + GFP_KERNEL | __GFP_ZERO); + if (!fc->fences) { + err = -ENOMEM; + goto err_chains; + } + + fc->tail = NULL; + for (i = 0; i < count; i++) { + fc->fences[i] = mock_fence(); + if (!fc->fences[i]) { + err = -ENOMEM; + goto unwind; + } + + fc->chains[i] = mock_chain(fc->tail, + fc->fences[i], + seqno_fn(i)); + if (!fc->chains[i]) { + err = -ENOMEM; + goto unwind; + } + + fc->tail = fc->chains[i]; + } + + fc->chain_length = i; + return 0; + +unwind: + for (i = 0; i < count; i++) { + dma_fence_put(fc->fences[i]); + dma_fence_put(fc->chains[i]); + } + kvfree(fc->fences); +err_chains: + kvfree(fc->chains); + return err; +} + +static void fence_chains_fini(struct fence_chains *fc) +{ + unsigned int i; + + for (i = 0; i < fc->chain_length; i++) { + dma_fence_signal(fc->fences[i]); + dma_fence_put(fc->fences[i]); + } + kvfree(fc->fences); + + for (i = 0; i < fc->chain_length; i++) + dma_fence_put(fc->chains[i]); + kvfree(fc->chains); +} + +static int find_seqno(void *arg) +{ + struct fence_chains fc; + struct dma_fence *fence; + int err; + int i; + + err = fence_chains_init(&fc, 64, seqno_inc); + if (err) + return err; + + fence = dma_fence_get(fc.tail); + err = dma_fence_chain_find_seqno(&fence, 0); + dma_fence_put(fence); + if (err) { + pr_err("Reported %d for find_seqno(0)!\n", err); + goto err; + } + + for (i = 0; i < fc.chain_length; i++) { + fence = dma_fence_get(fc.tail); + err = dma_fence_chain_find_seqno(&fence, i + 1); + dma_fence_put(fence); + if (err) { + pr_err("Reported %d for find_seqno(%d:%d)!\n", + err, fc.chain_length + 1, i + 1); + goto err; + } + if (fence != fc.chains[i]) { + pr_err("Incorrect fence reported by find_seqno(%d:%d)\n", + fc.chain_length + 1, i + 1); + err = -EINVAL; + goto err; + } + + dma_fence_get(fence); + err = dma_fence_chain_find_seqno(&fence, i + 1); + dma_fence_put(fence); + if (err) { + pr_err("Error reported for finding self\n"); + goto err; + } + if (fence != fc.chains[i]) { + pr_err("Incorrect fence reported by find self\n"); + err = -EINVAL; + goto err; + } + + dma_fence_get(fence); + err = dma_fence_chain_find_seqno(&fence, i + 2); + dma_fence_put(fence); + if (!err) { + pr_err("Error not reported for future fence: find_seqno(%d:%d)!\n", + i + 1, i + 2); + err = -EINVAL; + goto err; + } + + dma_fence_get(fence); + err = dma_fence_chain_find_seqno(&fence, i); + dma_fence_put(fence); + if (err) { + pr_err("Error reported for previous fence!\n"); + goto err; + } + if (i > 0 && fence != fc.chains[i - 1]) { + pr_err("Incorrect fence reported by find_seqno(%d:%d)\n", + i + 1, i); + err = -EINVAL; + goto err; + } + } + +err: + fence_chains_fini(&fc); + return err; +} + +static int find_signaled(void *arg) +{ + struct fence_chains fc; + struct dma_fence *fence; + int err; + + err = fence_chains_init(&fc, 2, seqno_inc); + if (err) + return err; + + dma_fence_signal(fc.fences[0]); + + fence = dma_fence_get(fc.tail); + err = dma_fence_chain_find_seqno(&fence, 1); + dma_fence_put(fence); + if (err) { + pr_err("Reported %d for find_seqno()!\n", err); + goto err; + } + + if (fence && fence != fc.chains[0]) { + pr_err("Incorrect chain-fence.seqno:%lld reported for completed seqno:1\n", + fence->seqno); + + dma_fence_get(fence); + err = dma_fence_chain_find_seqno(&fence, 1); + dma_fence_put(fence); + if (err) + pr_err("Reported %d for finding self!\n", err); + + err = -EINVAL; + } + +err: + fence_chains_fini(&fc); + return err; +} + +static int find_out_of_order(void *arg) +{ + struct fence_chains fc; + struct dma_fence *fence; + int err; + + err = fence_chains_init(&fc, 3, seqno_inc); + if (err) + return err; + + dma_fence_signal(fc.fences[1]); + + fence = dma_fence_get(fc.tail); + err = dma_fence_chain_find_seqno(&fence, 2); + dma_fence_put(fence); + if (err) { + pr_err("Reported %d for find_seqno()!\n", err); + goto err; + } + + if (fence && fence != fc.chains[1]) { + pr_err("Incorrect chain-fence.seqno:%lld reported for completed seqno:2\n", + fence->seqno); + + dma_fence_get(fence); + err = dma_fence_chain_find_seqno(&fence, 2); + dma_fence_put(fence); + if (err) + pr_err("Reported %d for finding self!\n", err); + + err = -EINVAL; + } + +err: + fence_chains_fini(&fc); + return err; +} + +static uint64_t seqno_inc2(unsigned int i) +{ + return 2 * i + 2; +} + +static int find_gap(void *arg) +{ + struct fence_chains fc; + struct dma_fence *fence; + int err; + int i; + + err = fence_chains_init(&fc, 64, seqno_inc2); + if (err) + return err; + + for (i = 0; i < fc.chain_length; i++) { + fence = dma_fence_get(fc.tail); + err = dma_fence_chain_find_seqno(&fence, 2 * i + 1); + dma_fence_put(fence); + if (err) { + pr_err("Reported %d for find_seqno(%d:%d)!\n", + err, fc.chain_length + 1, 2 * i + 1); + goto err; + } + if (fence != fc.chains[i]) { + pr_err("Incorrect fence.seqno:%lld reported by find_seqno(%d:%d)\n", + fence->seqno, + fc.chain_length + 1, + 2 * i + 1); + err = -EINVAL; + goto err; + } + + dma_fence_get(fence); + err = dma_fence_chain_find_seqno(&fence, 2 * i + 2); + dma_fence_put(fence); + if (err) { + pr_err("Error reported for finding self\n"); + goto err; + } + if (fence != fc.chains[i]) { + pr_err("Incorrect fence reported by find self\n"); + err = -EINVAL; + goto err; + } + } + +err: + fence_chains_fini(&fc); + return err; +} + +struct find_race { + struct fence_chains fc; + atomic_t children; +}; + +static int __find_race(void *arg) +{ + struct find_race *data = arg; + int err = 0; + + while (!kthread_should_stop()) { + struct dma_fence *fence = dma_fence_get(data->fc.tail); + int seqno; + + seqno = prandom_u32_max(data->fc.chain_length) + 1; + + err = dma_fence_chain_find_seqno(&fence, seqno); + if (err) { + pr_err("Failed to find fence seqno:%d\n", + seqno); + dma_fence_put(fence); + break; + } + if (!fence) + goto signal; + + err = dma_fence_chain_find_seqno(&fence, seqno); + if (err) { + pr_err("Reported an invalid fence for find-self:%d\n", + seqno); + dma_fence_put(fence); + break; + } + + if (fence->seqno < seqno) { + pr_err("Reported an earlier fence.seqno:%lld for seqno:%d\n", + fence->seqno, seqno); + err = -EINVAL; + dma_fence_put(fence); + break; + } + + dma_fence_put(fence); + +signal: + seqno = prandom_u32_max(data->fc.chain_length - 1); + dma_fence_signal(data->fc.fences[seqno]); + cond_resched(); + } + + if (atomic_dec_and_test(&data->children)) + wake_up_var(&data->children); + return err; +} + +static int find_race(void *arg) +{ + struct find_race data; + int ncpus = num_online_cpus(); + struct task_struct **threads; + unsigned long count; + int err; + int i; + + err = fence_chains_init(&data.fc, 64 << 10, seqno_inc); + if (err) + return err; + + threads = kmalloc_array(ncpus, sizeof(*threads), GFP_KERNEL); + if (!threads) { + err = -ENOMEM; + goto err; + } + + atomic_set(&data.children, 0); + for (i = 0; i < ncpus; i++) { + threads[i] = kthread_run(__find_race, &data, "dmabuf/%d", i); + if (IS_ERR(threads[i])) { + ncpus = i; + break; + } + atomic_inc(&data.children); + get_task_struct(threads[i]); + } + + wait_var_event_timeout(&data.children, + !atomic_read(&data.children), + 5 * HZ); + + for (i = 0; i < ncpus; i++) { + int ret; + + ret = kthread_stop(threads[i]); + if (ret && !err) + err = ret; + put_task_struct(threads[i]); + } + kfree(threads); + + count = 0; + for (i = 0; i < data.fc.chain_length; i++) + if (dma_fence_is_signaled(data.fc.fences[i])) + count++; + pr_info("Completed %lu cycles\n", count); + +err: + fence_chains_fini(&data.fc); + return err; +} + +static int signal_forward(void *arg) +{ + struct fence_chains fc; + int err; + int i; + + err = fence_chains_init(&fc, 64, seqno_inc); + if (err) + return err; + + for (i = 0; i < fc.chain_length; i++) { + dma_fence_signal(fc.fences[i]); + + if (!dma_fence_is_signaled(fc.chains[i])) { + pr_err("chain[%d] not signaled!\n", i); + err = -EINVAL; + goto err; + } + + if (i + 1 < fc.chain_length && + dma_fence_is_signaled(fc.chains[i + 1])) { + pr_err("chain[%d] is signaled!\n", i); + err = -EINVAL; + goto err; + } + } + +err: + fence_chains_fini(&fc); + return err; +} + +static int signal_backward(void *arg) +{ + struct fence_chains fc; + int err; + int i; + + err = fence_chains_init(&fc, 64, seqno_inc); + if (err) + return err; + + for (i = fc.chain_length; i--; ) { + dma_fence_signal(fc.fences[i]); + + if (i > 0 && dma_fence_is_signaled(fc.chains[i])) { + pr_err("chain[%d] is signaled!\n", i); + err = -EINVAL; + goto err; + } + } + + for (i = 0; i < fc.chain_length; i++) { + if (!dma_fence_is_signaled(fc.chains[i])) { + pr_err("chain[%d] was not signaled!\n", i); + err = -EINVAL; + goto err; + } + } + +err: + fence_chains_fini(&fc); + return err; +} + +static int __wait_fence_chains(void *arg) +{ + struct fence_chains *fc = arg; + + if (dma_fence_wait(fc->tail, false)) + return -EIO; + + return 0; +} + +static int wait_forward(void *arg) +{ + struct fence_chains fc; + struct task_struct *tsk; + int err; + int i; + + err = fence_chains_init(&fc, 64 << 10, seqno_inc); + if (err) + return err; + + tsk = kthread_run(__wait_fence_chains, &fc, "dmabuf/wait"); + if (IS_ERR(tsk)) { + err = PTR_ERR(tsk); + goto err; + } + get_task_struct(tsk); + yield_to(tsk, true); + + for (i = 0; i < fc.chain_length; i++) + dma_fence_signal(fc.fences[i]); + + err = kthread_stop(tsk); + put_task_struct(tsk); + +err: + fence_chains_fini(&fc); + return err; +} + +static int wait_backward(void *arg) +{ + struct fence_chains fc; + struct task_struct *tsk; + int err; + int i; + + err = fence_chains_init(&fc, 64 << 10, seqno_inc); + if (err) + return err; + + tsk = kthread_run(__wait_fence_chains, &fc, "dmabuf/wait"); + if (IS_ERR(tsk)) { + err = PTR_ERR(tsk); + goto err; + } + get_task_struct(tsk); + yield_to(tsk, true); + + for (i = fc.chain_length; i--; ) + dma_fence_signal(fc.fences[i]); + + err = kthread_stop(tsk); + put_task_struct(tsk); + +err: + fence_chains_fini(&fc); + return err; +} + +static void randomise_fences(struct fence_chains *fc) +{ + unsigned int count = fc->chain_length; + + /* Fisher-Yates shuffle courtesy of Knuth */ + while (--count) { + unsigned int swp; + + swp = prandom_u32_max(count + 1); + if (swp == count) + continue; + + swap(fc->fences[count], fc->fences[swp]); + } +} + +static int wait_random(void *arg) +{ + struct fence_chains fc; + struct task_struct *tsk; + int err; + int i; + + err = fence_chains_init(&fc, 64 << 10, seqno_inc); + if (err) + return err; + + randomise_fences(&fc); + + tsk = kthread_run(__wait_fence_chains, &fc, "dmabuf/wait"); + if (IS_ERR(tsk)) { + err = PTR_ERR(tsk); + goto err; + } + get_task_struct(tsk); + yield_to(tsk, true); + + for (i = 0; i < fc.chain_length; i++) + dma_fence_signal(fc.fences[i]); + + err = kthread_stop(tsk); + put_task_struct(tsk); + +err: + fence_chains_fini(&fc); + return err; +} + +int dma_fence_chain(void) +{ + static const struct subtest tests[] = { + SUBTEST(sanitycheck), + SUBTEST(find_seqno), + SUBTEST(find_signaled), + SUBTEST(find_out_of_order), + SUBTEST(find_gap), + SUBTEST(find_race), + SUBTEST(signal_forward), + SUBTEST(signal_backward), + SUBTEST(wait_forward), + SUBTEST(wait_backward), + SUBTEST(wait_random), + }; + int ret; + + pr_info("sizeof(dma_fence_chain)=%zu\n", + sizeof(struct dma_fence_chain)); + + slab_fences = KMEM_CACHE(mock_fence, + SLAB_TYPESAFE_BY_RCU | + SLAB_HWCACHE_ALIGN); + if (!slab_fences) + return -ENOMEM; + + ret = subtests(tests, NULL); + + kmem_cache_destroy(slab_fences); + return ret; +}