Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932747AbdIRPbh (ORCPT ); Mon, 18 Sep 2017 11:31:37 -0400 Received: from mga01.intel.com ([192.55.52.88]:35539 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932594AbdIRPbb (ORCPT ); Mon, 18 Sep 2017 11:31:31 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.42,413,1500966000"; d="scan'208";a="312962859" From: Mika Westerberg To: Greg Kroah-Hartman , "David S . Miller" Cc: Andreas Noever , Michael Jamet , Yehezkel Bernat , Amir Levy , Mario.Limonciello@dell.com, Lukas Wunner , Andy Shevchenko , Mika Westerberg , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH 12/16] thunderbolt: Use spinlock in NHI serialization Date: Mon, 18 Sep 2017 18:30:45 +0300 Message-Id: <20170918153049.44185-13-mika.westerberg@linux.intel.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170918153049.44185-1-mika.westerberg@linux.intel.com> References: <20170918153049.44185-1-mika.westerberg@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6166 Lines: 204 This is needed because ring polling functionality can be called from atomic contexts when networking and other high-speed traffic is transferred over a Thunderbolt cable. Signed-off-by: Mika Westerberg Reviewed-by: Michael Jamet Reviewed-by: Yehezkel Bernat --- drivers/thunderbolt/nhi.c | 75 +++++++++++++++++++++++++-------------------- include/linux/thunderbolt.h | 2 +- 2 files changed, 42 insertions(+), 35 deletions(-) diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c index d1ad37c6eccf..cf1397afa72f 100644 --- a/drivers/thunderbolt/nhi.c +++ b/drivers/thunderbolt/nhi.c @@ -327,21 +327,9 @@ static struct tb_ring *tb_ring_alloc(struct tb_nhi *nhi, u32 hop, int size, if (transmit && hop == RING_E2E_UNUSED_HOPID) return NULL; - mutex_lock(&nhi->lock); - if (hop >= nhi->hop_count) { - dev_WARN(&nhi->pdev->dev, "invalid hop: %d\n", hop); - goto err; - } - if (transmit && nhi->tx_rings[hop]) { - dev_WARN(&nhi->pdev->dev, "TX hop %d already allocated\n", hop); - goto err; - } else if (!transmit && nhi->rx_rings[hop]) { - dev_WARN(&nhi->pdev->dev, "RX hop %d already allocated\n", hop); - goto err; - } ring = kzalloc(sizeof(*ring), GFP_KERNEL); if (!ring) - goto err; + return NULL; spin_lock_init(&ring->lock); INIT_LIST_HEAD(&ring->queue); @@ -359,25 +347,45 @@ static struct tb_ring *tb_ring_alloc(struct tb_nhi *nhi, u32 hop, int size, ring->tail = 0; ring->running = false; - if (ring_request_msix(ring, flags & RING_FLAG_NO_SUSPEND)) - goto err; - ring->descriptors = dma_alloc_coherent(&ring->nhi->pdev->dev, size * sizeof(*ring->descriptors), &ring->descriptors_dma, GFP_KERNEL | __GFP_ZERO); if (!ring->descriptors) - goto err; + goto err_free_ring; + if (ring_request_msix(ring, flags & RING_FLAG_NO_SUSPEND)) + goto err_free_descs; + + spin_lock_irq(&nhi->lock); + if (hop >= nhi->hop_count) { + dev_WARN(&nhi->pdev->dev, "invalid hop: %d\n", hop); + goto err_release_msix; + } + if (transmit && nhi->tx_rings[hop]) { + dev_WARN(&nhi->pdev->dev, "TX hop %d already allocated\n", hop); + goto err_release_msix; + } else if (!transmit && nhi->rx_rings[hop]) { + dev_WARN(&nhi->pdev->dev, "RX hop %d already allocated\n", hop); + goto err_release_msix; + } if (transmit) nhi->tx_rings[hop] = ring; else nhi->rx_rings[hop] = ring; - mutex_unlock(&nhi->lock); + spin_unlock_irq(&nhi->lock); + return ring; -err: +err_release_msix: + spin_unlock_irq(&nhi->lock); + ring_release_msix(ring); +err_free_descs: + dma_free_coherent(&ring->nhi->pdev->dev, + ring->size * sizeof(*ring->descriptors), + ring->descriptors, ring->descriptors_dma); +err_free_ring: kfree(ring); - mutex_unlock(&nhi->lock); + return NULL; } @@ -421,8 +429,8 @@ void tb_ring_start(struct tb_ring *ring) u16 frame_size; u32 flags; - mutex_lock(&ring->nhi->lock); - spin_lock_irq(&ring->lock); + spin_lock_irq(&ring->nhi->lock); + spin_lock(&ring->lock); if (ring->nhi->going_away) goto err; if (ring->running) { @@ -469,8 +477,8 @@ void tb_ring_start(struct tb_ring *ring) ring_interrupt_active(ring, true); ring->running = true; err: - spin_unlock_irq(&ring->lock); - mutex_unlock(&ring->nhi->lock); + spin_unlock(&ring->lock); + spin_unlock_irq(&ring->nhi->lock); } EXPORT_SYMBOL_GPL(tb_ring_start); @@ -489,8 +497,8 @@ EXPORT_SYMBOL_GPL(tb_ring_start); */ void tb_ring_stop(struct tb_ring *ring) { - mutex_lock(&ring->nhi->lock); - spin_lock_irq(&ring->lock); + spin_lock_irq(&ring->nhi->lock); + spin_lock(&ring->lock); dev_info(&ring->nhi->pdev->dev, "stopping %s %d\n", RING_TYPE(ring), ring->hop); if (ring->nhi->going_away) @@ -511,8 +519,8 @@ void tb_ring_stop(struct tb_ring *ring) ring->running = false; err: - spin_unlock_irq(&ring->lock); - mutex_unlock(&ring->nhi->lock); + spin_unlock(&ring->lock); + spin_unlock_irq(&ring->nhi->lock); /* * schedule ring->work to invoke callbacks on all remaining frames. @@ -534,7 +542,7 @@ EXPORT_SYMBOL_GPL(tb_ring_stop); */ void tb_ring_free(struct tb_ring *ring) { - mutex_lock(&ring->nhi->lock); + spin_lock_irq(&ring->nhi->lock); /* * Dissociate the ring from the NHI. This also ensures that * nhi_interrupt_work cannot reschedule ring->work. @@ -564,7 +572,7 @@ void tb_ring_free(struct tb_ring *ring) RING_TYPE(ring), ring->hop); - mutex_unlock(&ring->nhi->lock); + spin_unlock_irq(&ring->nhi->lock); /** * ring->work can no longer be scheduled (it is scheduled only * by nhi_interrupt_work, ring_stop and ring_msix). Wait for it @@ -639,7 +647,7 @@ static void nhi_interrupt_work(struct work_struct *work) int type = 0; /* current interrupt type 0: TX, 1: RX, 2: RX overflow */ struct tb_ring *ring; - mutex_lock(&nhi->lock); + spin_lock_irq(&nhi->lock); /* * Starting at REG_RING_NOTIFY_BASE there are three status bitfields @@ -677,7 +685,7 @@ static void nhi_interrupt_work(struct work_struct *work) /* we do not check ring->running, this is done in ring->work */ schedule_work(&ring->work); } - mutex_unlock(&nhi->lock); + spin_unlock_irq(&nhi->lock); } static irqreturn_t nhi_msi(int irq, void *data) @@ -766,7 +774,6 @@ static void nhi_shutdown(struct tb_nhi *nhi) devm_free_irq(&nhi->pdev->dev, nhi->pdev->irq, nhi); flush_work(&nhi->interrupt_work); } - mutex_destroy(&nhi->lock); ida_destroy(&nhi->msix_ida); } @@ -855,7 +862,7 @@ static int nhi_probe(struct pci_dev *pdev, const struct pci_device_id *id) return res; } - mutex_init(&nhi->lock); + spin_lock_init(&nhi->lock); pci_set_master(pdev); diff --git a/include/linux/thunderbolt.h b/include/linux/thunderbolt.h index 51af0a5fa52f..62adb97d77f1 100644 --- a/include/linux/thunderbolt.h +++ b/include/linux/thunderbolt.h @@ -415,7 +415,7 @@ static inline struct tb_xdomain *tb_service_parent(struct tb_service *svc) * @hop_count: Number of rings (end point hops) supported by NHI. */ struct tb_nhi { - struct mutex lock; + spinlock_t lock; struct pci_dev *pdev; void __iomem *iobase; struct tb_ring **tx_rings; -- 2.13.5