From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D54DC4338F for ; Fri, 20 Aug 2021 15:07:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EE3E661053 for ; Fri, 20 Aug 2021 15:07:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241002AbhHTPIJ (ORCPT ); Fri, 20 Aug 2021 11:08:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:50360 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240956AbhHTPIG (ORCPT ); Fri, 20 Aug 2021 11:08:06 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4D18D60FDA for ; Fri, 20 Aug 2021 15:07:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629472048; bh=tWufcxFkKtxB7AT4OiAkVQ5Q/bP625jdgo4IPuIhtJA=; h=From:To:Subject:Date:In-Reply-To:References:From; b=OBjnP7LuhmV64IZcPMGG04g7VUPDl1VbuV7uz+aedQv3j8x7qIXPSOtRxAz1i1Zd5 0lCWMozyWnIF2/FoygycH6z0gZ0GmMFpnfCOGPIanJoYARu6OVsUtA/QSY1TvH05PB GgTvNFLz45n6cCWHwyd62F9MGjIjVt+iZw1AojZx/OAxdu6VpRNCO08WevD3tvIfBM hUWFiXRLzu+KfctrktC2coKh00652kvPqRHsgBe7qSeNTLv5fD6nhRXKQ+a2PjZKOO h4l8xDh0NktYy1DXwNAyfyJq9QP6CWWvZzAVPP5c3kqp7xws0HlBZP+GONRexX9ZiX X7sFalt4+ZN5A== From: Oded Gabbay To: linux-kernel@vger.kernel.org Subject: [PATCH 2/4] habanalabs: disable IRQ in user interrupts spinlock Date: Fri, 20 Aug 2021 18:07:17 +0300 Message-Id: <20210820150719.67934-2-ogabbay@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210820150719.67934-1-ogabbay@kernel.org> References: <20210820150719.67934-1-ogabbay@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Because this spinlock is taken in an interrupt handler, we must use the spin_lock_irqsave/irqrestore version to disable the interrupts on the local CPU. Otherwise, we can have a potential deadlock (if the interrupt handler is scheduled to run on the same cpu that the code who took the lock was running on). Signed-off-by: Oded Gabbay --- .../habanalabs/common/command_submission.c | 25 ++++++++++--------- 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/drivers/misc/habanalabs/common/command_submission.c b/drivers/misc/habanalabs/common/command_submission.c index 3a67265312ee..8a2f75de6df8 100644 --- a/drivers/misc/habanalabs/common/command_submission.c +++ b/drivers/misc/habanalabs/common/command_submission.c @@ -923,13 +923,14 @@ static void wake_pending_user_interrupt_threads(struct hl_user_interrupt *interrupt) { struct hl_user_pending_interrupt *pend; + unsigned long flags; - spin_lock(&interrupt->wait_list_lock); + spin_lock_irqsave(&interrupt->wait_list_lock, flags); list_for_each_entry(pend, &interrupt->wait_list_head, wait_list_node) { pend->fence.error = -EIO; complete_all(&pend->fence.completion); } - spin_unlock(&interrupt->wait_list_lock); + spin_unlock_irqrestore(&interrupt->wait_list_lock, flags); } void hl_release_pending_user_interrupts(struct hl_device *hdev) @@ -2714,9 +2715,9 @@ static int _hl_interrupt_wait_ioctl(struct hl_device *hdev, struct hl_ctx *ctx, { struct hl_user_pending_interrupt *pend; struct hl_user_interrupt *interrupt; - unsigned long timeout; - long completion_rc; + unsigned long timeout, flags; u32 completion_value; + long completion_rc; int rc = 0; if (timeout_us == U32_MAX) @@ -2739,7 +2740,7 @@ static int _hl_interrupt_wait_ioctl(struct hl_device *hdev, struct hl_ctx *ctx, else interrupt = &hdev->user_interrupt[interrupt_offset]; - spin_lock(&interrupt->wait_list_lock); + spin_lock_irqsave(&interrupt->wait_list_lock, flags); if (!hl_device_operational(hdev, NULL)) { rc = -EPERM; goto unlock_and_free_fence; @@ -2765,7 +2766,7 @@ static int _hl_interrupt_wait_ioctl(struct hl_device *hdev, struct hl_ctx *ctx, * handler to monitor */ list_add_tail(&pend->wait_list_node, &interrupt->wait_list_head); - spin_unlock(&interrupt->wait_list_lock); + spin_unlock_irqrestore(&interrupt->wait_list_lock, flags); wait_again: /* Wait for interrupt handler to signal completion */ @@ -2777,12 +2778,12 @@ static int _hl_interrupt_wait_ioctl(struct hl_device *hdev, struct hl_ctx *ctx, * If comparison fails, keep waiting until timeout expires */ if (completion_rc > 0) { - spin_lock(&interrupt->wait_list_lock); + spin_lock_irqsave(&interrupt->wait_list_lock, flags); if (copy_from_user(&completion_value, u64_to_user_ptr(user_address), 4)) { - spin_unlock(&interrupt->wait_list_lock); + spin_unlock_irqrestore(&interrupt->wait_list_lock, flags); dev_err(hdev->dev, "Failed to copy completion value from user\n"); @@ -2792,13 +2793,13 @@ static int _hl_interrupt_wait_ioctl(struct hl_device *hdev, struct hl_ctx *ctx, } if (completion_value >= target_value) { - spin_unlock(&interrupt->wait_list_lock); + spin_unlock_irqrestore(&interrupt->wait_list_lock, flags); *status = CS_WAIT_STATUS_COMPLETED; } else { reinit_completion(&pend->fence.completion); timeout = completion_rc; - spin_unlock(&interrupt->wait_list_lock); + spin_unlock_irqrestore(&interrupt->wait_list_lock, flags); goto wait_again; } } else if (completion_rc == -ERESTARTSYS) { @@ -2812,11 +2813,11 @@ static int _hl_interrupt_wait_ioctl(struct hl_device *hdev, struct hl_ctx *ctx, } remove_pending_user_interrupt: - spin_lock(&interrupt->wait_list_lock); + spin_lock_irqsave(&interrupt->wait_list_lock, flags); list_del(&pend->wait_list_node); unlock_and_free_fence: - spin_unlock(&interrupt->wait_list_lock); + spin_unlock_irqrestore(&interrupt->wait_list_lock, flags); kfree(pend); hl_ctx_put(ctx); -- 2.17.1