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[212.55.6.210]) by smtp.gmail.com with ESMTPSA id h4-20020a056000000400b00327df8fcbd9sm1867041wrx.9.2023.10.05.06.53.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Oct 2023 06:53:34 -0700 (PDT) From: Xabier Marquiegui To: netdev@vger.kernel.org Cc: richardcochran@gmail.com, tglx@linutronix.de, jstultz@google.com, horms@kernel.org, chrony-dev@chrony.tuxfamily.org, mlichvar@redhat.com, reibax@gmail.com, ntp-lists@mattcorallo.com, vinicius.gomes@intel.com, alex.maftei@amd.com, davem@davemloft.net, rrameshbabu@nvidia.com, shuah@kernel.org Subject: [PATCH net-next v4 3/6] ptp: support multiple timestamp event readers Date: Thu, 5 Oct 2023 15:53:13 +0200 Message-Id: <32cf9345e1f06f62ad36b54bdd107baea7b079b6.1696511486.git.reibax@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org Use linked lists to create one event queue per open file. This enables simultaneous readers for timestamp event queues. Signed-off-by: Xabier Marquiegui Suggested-by: Richard Cochran --- v4: - split modifications in different patches for improved organization - simplified release procedures - remove unnecessary checks v3: https://lore.kernel.org/netdev/20230928133544.3642650-3-reibax@gmail.com/ - fix use of safe and non safe linked lists for loops - introduce new posix_clock private_data and ida object ids for better dicrimination of timestamp consumers - safer resource release procedures v2: https://lore.kernel.org/netdev/20230912220217.2008895-2-reibax@gmail.com/ - fix ptp_poll() return value - Style changes to comform to checkpatch strict suggestions - more coherent ptp_read error exit routines v1: https://lore.kernel.org/netdev/20230906104754.1324412-3-reibax@gmail.com/ --- drivers/ptp/ptp_chardev.c | 68 ++++++++++++++++++++++++++++----------- drivers/ptp/ptp_clock.c | 6 ++-- drivers/ptp/ptp_private.h | 1 - drivers/ptp/ptp_sysfs.c | 9 +++--- 4 files changed, 55 insertions(+), 29 deletions(-) diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c index aa1990d2ab46..abe94bb80cf6 100644 --- a/drivers/ptp/ptp_chardev.c +++ b/drivers/ptp/ptp_chardev.c @@ -103,6 +103,31 @@ int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin, int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode) { + struct ptp_clock *ptp = + container_of(pccontext->clk, struct ptp_clock, clock); + struct timestamp_event_queue *queue; + + queue = kzalloc(sizeof(*queue), GFP_KERNEL); + if (!queue) + return -EINVAL; + spin_lock_init(&queue->lock); + list_add_tail(&queue->qlist, &ptp->tsevqs); + pccontext->private_clkdata = queue; + return 0; +} + +int ptp_release(struct posix_clock_context *pccontext) +{ + struct timestamp_event_queue *queue = pccontext->private_clkdata; + unsigned long flags; + + if (queue) { + pccontext->private_clkdata = NULL; + spin_lock_irqsave(&queue->lock, flags); + list_del(&queue->qlist); + spin_unlock_irqrestore(&queue->lock, flags); + kfree(queue); + } return 0; } @@ -441,10 +466,11 @@ __poll_t ptp_poll(struct posix_clock_context *pccontext, struct file *fp, container_of(pccontext->clk, struct ptp_clock, clock); struct timestamp_event_queue *queue; - poll_wait(fp, &ptp->tsev_wq, wait); + queue = pccontext->private_clkdata; + if (!queue) + return EPOLLERR; - /* Extract only the first element in the queue list */ - queue = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue, qlist); + poll_wait(fp, &ptp->tsev_wq, wait); return queue_cnt(queue) ? EPOLLIN : 0; } @@ -462,36 +488,36 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags, size_t qcnt, i; int result; - /* Extract only the first element in the queue list */ - queue = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue, - qlist); + queue = pccontext->private_clkdata; + if (!queue) { + result = -EINVAL; + goto exit; + } - if (cnt % sizeof(struct ptp_extts_event) != 0) - return -EINVAL; + if (cnt % sizeof(struct ptp_extts_event) != 0) { + result = -EINVAL; + goto exit; + } if (cnt > EXTTS_BUFSIZE) cnt = EXTTS_BUFSIZE; cnt = cnt / sizeof(struct ptp_extts_event); - if (mutex_lock_interruptible(&ptp->tsevq_mux)) - return -ERESTARTSYS; - if (wait_event_interruptible(ptp->tsev_wq, ptp->defunct || queue_cnt(queue))) { - mutex_unlock(&ptp->tsevq_mux); return -ERESTARTSYS; } if (ptp->defunct) { - mutex_unlock(&ptp->tsevq_mux); - return -ENODEV; + result = -ENODEV; + goto exit; } event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL); if (!event) { - mutex_unlock(&ptp->tsevq_mux); - return -ENOMEM; + result = -ENOMEM; + goto exit; } spin_lock_irqsave(&queue->lock, flags); @@ -510,12 +536,16 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags, cnt = cnt * sizeof(struct ptp_extts_event); - mutex_unlock(&ptp->tsevq_mux); - result = cnt; - if (copy_to_user(buf, event, cnt)) + if (copy_to_user(buf, event, cnt)) { result = -EFAULT; + goto free_event; + } +free_event: kfree(event); +exit: + if (result < 0) + ptp_release(pccontext); return result; } diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c index 157ef25bc1b1..74f1ce2dbccb 100644 --- a/drivers/ptp/ptp_clock.c +++ b/drivers/ptp/ptp_clock.c @@ -162,6 +162,7 @@ static struct posix_clock_operations ptp_clock_ops = { .clock_settime = ptp_clock_settime, .ioctl = ptp_ioctl, .open = ptp_open, + .release = ptp_release, .poll = ptp_poll, .read = ptp_read, }; @@ -174,7 +175,6 @@ static void ptp_clock_release(struct device *dev) ptp_cleanup_pin_groups(ptp); kfree(ptp->vclock_index); - mutex_destroy(&ptp->tsevq_mux); mutex_destroy(&ptp->pincfg_mux); mutex_destroy(&ptp->n_vclocks_mux); /* Delete first entry */ @@ -242,9 +242,8 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, queue = kzalloc(sizeof(*queue), GFP_KERNEL); if (!queue) goto no_memory_queue; - spin_lock_init(&queue->lock); list_add_tail(&queue->qlist, &ptp->tsevqs); - mutex_init(&ptp->tsevq_mux); + spin_lock_init(&queue->lock); mutex_init(&ptp->pincfg_mux); mutex_init(&ptp->n_vclocks_mux); init_waitqueue_head(&ptp->tsev_wq); @@ -345,7 +344,6 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, if (ptp->kworker) kthread_destroy_worker(ptp->kworker); kworker_err: - mutex_destroy(&ptp->tsevq_mux); mutex_destroy(&ptp->pincfg_mux); mutex_destroy(&ptp->n_vclocks_mux); list_del(&queue->qlist); diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h index cc8186a92eec..9d5f3d95058e 100644 --- a/drivers/ptp/ptp_private.h +++ b/drivers/ptp/ptp_private.h @@ -38,7 +38,6 @@ struct ptp_clock { struct pps_device *pps_source; long dialed_frequency; /* remembers the frequency adjustment */ struct list_head tsevqs; /* timestamp fifo list */ - struct mutex tsevq_mux; /* one process at a time reading the fifo */ struct mutex pincfg_mux; /* protect concurrent info->pin_config access */ wait_queue_head_t tsev_wq; int defunct; /* tells readers to go away when clock is being removed */ diff --git a/drivers/ptp/ptp_sysfs.c b/drivers/ptp/ptp_sysfs.c index 2675f383cd0a..7d023d9d0acb 100644 --- a/drivers/ptp/ptp_sysfs.c +++ b/drivers/ptp/ptp_sysfs.c @@ -81,15 +81,15 @@ static ssize_t extts_fifo_show(struct device *dev, size_t qcnt; int cnt = 0; + cnt = list_count_nodes(&ptp->tsevqs); + if (cnt <= 0) + goto out; + /* The sysfs fifo will always draw from the fist queue */ queue = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue, qlist); memset(&event, 0, sizeof(event)); - - if (mutex_lock_interruptible(&ptp->tsevq_mux)) - return -ERESTARTSYS; - spin_lock_irqsave(&queue->lock, flags); qcnt = queue_cnt(queue); if (qcnt) { @@ -104,7 +104,6 @@ static ssize_t extts_fifo_show(struct device *dev, cnt = snprintf(page, PAGE_SIZE, "%u %lld %u\n", event.index, event.t.sec, event.t.nsec); out: - mutex_unlock(&ptp->tsevq_mux); return cnt; } static DEVICE_ATTR(fifo, 0444, extts_fifo_show, NULL);