From patchwork Thu Jun 20 10:31:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Garry X-Patchwork-Id: 167317 Delivered-To: patch@linaro.org Received: by 2002:ac9:6410:0:0:0:0:0 with SMTP id r16csp1665004ock; Thu, 20 Jun 2019 03:33:42 -0700 (PDT) X-Google-Smtp-Source: APXvYqzDQRxroGe+f8lpkMnhnLnK/r9QQk2jbgSIiZtkunynT6qCAjdAvwQKOTLqhO4RP/LmlP9z X-Received: by 2002:a62:e910:: with SMTP id j16mr28335669pfh.123.1561026822649; Thu, 20 Jun 2019 03:33:42 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1561026822; cv=none; d=google.com; s=arc-20160816; b=JwiVwf8MYMnON7buZmNqu96f4LlJNU8vEjt+J/8alS2F45SlQey4H1ZKHgE9TzfHvq yqkmwqLY1K7MuPBXJKo+09iNEYG/bsezT0Ic/xxeBFhQDF3ZEiWJc3zD7zxC2dOzqWC/ iPoVdq7c5xUKfUYRCCqKpXwrTyBFOsw8AdPoSuaTWHaE16BBsFkwj3Ir5s4vXk468Ef6 PmEbjlkxvDlx1a+EnB7M+7T9rt3AIfbtAif/n6l0EQ0XUCzyJRhXPHgwKmpZddc7/OWz i/gvk9Q+WTBNlYTBsA61xTvi2o75XtiCFwgpiv0zGVKMaWYlAcFTtRt1ichpR8TnU/cP HYgA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from; bh=ta+NRQcA1wumpPFE5rSDQql9RlIhpY74xnzbHacfSJo=; b=x6H0RqbFwDn85+bIrz8OKhp7+aq+1p/yMUEtXhPkDdIPlhvNJHSrFiP+xBhp1pL0or 44y6uvb41uKjI4OcGfCWSch6hxwihdCj0brD+tkMszr1FlyFGPYvXBcW2Evkija5PYQH sWRwmuoQRH70/UpuTHHTxKlDrbFN0uJmECXHaF5kPk7WnSUp1QtyMtdOQdF1Agdl4+AV A/R0ku97Y2KlqkLeK6JipMNJNJmA7V9GnWb7wNTIhj8+B/ioYi9C9zN367/P6hfDxaVL 2jYnzAhnBlp486uEQuOohkKKEoq3KE/5LIQMW7/Rcq+lq0stguQHI8h7zOvFlYed+aIr KyEw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id f17si5513824pgv.338.2019.06.20.03.33.42; Thu, 20 Jun 2019 03:33:42 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731563AbfFTKdk (ORCPT + 30 others); Thu, 20 Jun 2019 06:33:40 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:18646 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726081AbfFTKdf (ORCPT ); Thu, 20 Jun 2019 06:33:35 -0400 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id DCC7BD826ACA1CC4E4BC; Thu, 20 Jun 2019 18:33:32 +0800 (CST) Received: from localhost.localdomain (10.67.212.75) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.439.0; Thu, 20 Jun 2019 18:33:26 +0800 From: John Garry To: CC: , , , , , , John Garry Subject: [PATCH 4/5] bus: hisi_lpc: Add .remove method to avoid driver unbind crash Date: Thu, 20 Jun 2019 18:31:55 +0800 Message-ID: <1561026716-140537-5-git-send-email-john.garry@huawei.com> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1561026716-140537-1-git-send-email-john.garry@huawei.com> References: <1561026716-140537-1-git-send-email-john.garry@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.212.75] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The original driver author seemed to be under the impression that a driver cannot be removed if it does not have a .remove method. Or maybe if it is a built-in platform driver. This is not true. This crash can be created: root@ubuntu:/sys/bus/platform/drivers/hisi-lpc# echo HISI0191\:00 > unbind root@ubuntu:/sys/bus/platform/drivers/hisi-lpc# ipmitool raw 6 1 Unable to handle kernel paging request at virtual address ffff000010035010 Mem abort info: ESR = 0x96000047 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000047 CM = 0, WnR = 1 swapper pgtable: 4k pages, 48-bit VAs, pgdp=000000000118b000 [ffff000010035010] pgd=0000041ffbfff003, pud=0000041ffbffe003, pmd=0000041ffbffd003, pte=0000000000000000 Internal error: Oops: 96000047 [#1] PREEMPT SMP Modules linked in: CPU: 17 PID: 1473 Comm: ipmitool Not tainted 5.2.0-rc5-00003-gf68c53b414a3-dirty #198 Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon D05 IT21 Nemo 2.0 RC0 04/18/2018 pstate: 20000085 (nzCv daIf -PAN -UAO) pc : hisi_lpc_target_in+0x7c/0x120 lr : hisi_lpc_target_in+0x70/0x120 sp : ffff00001efe3930 x29: ffff00001efe3930 x28: ffff841f9f599200 x27: 0000000000000002 x26: 0000000000000000 x25: 0000000000000080 x24: 00000000000000e4 x23: 0000000000000000 x22: 0000000000000064 x21: ffff801fb667d280 x20: 0000000000000001 x19: ffff00001efe39ac x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000 x8 : ffff841febe60340 x7 : ffff801fb55c52e8 x6 : 0000000000000000 x5 : 0000000000ffc0e3 x4 : 0000000000000001 x3 : ffff801fb667d280 x2 : 0000000000000001 x1 : ffff000010035010 x0 : ffff000010035000 Call trace: hisi_lpc_target_in+0x7c/0x120 hisi_lpc_comm_in+0x88/0x98 logic_inb+0x5c/0xb8 port_inb+0x18/0x20 bt_event+0x38/0x808 smi_event_handler+0x4c/0x5a0 check_start_timer_thread.part.4+0x40/0x58 sender+0x78/0x88 smi_send.isra.6+0x94/0x108 i_ipmi_request+0x2c4/0x8f8 ipmi_request_settime+0x124/0x160 handle_send_req+0x19c/0x208 ipmi_ioctl+0x2c0/0x990 do_vfs_ioctl+0xb8/0x8f8 ksys_ioctl+0x80/0xb8 __arm64_sys_ioctl+0x1c/0x28 el0_svc_common.constprop.0+0x64/0x160 el0_svc_handler+0x28/0x78 el0_svc+0x8/0xc Code: 941d1511 aa0003f9 f94006a0 91004001 (b9000034) ---[ end trace aa842b86af7069e4 ]--- The problem here is that the host goes away but the associated logical PIO region remains registered, as do the child devices. Fix by adding a .remove method to tidy-up by removing the child devices and unregistering the logical PIO region. Fixes: adf38bb0b595 ("HISI LPC: Support the LPC host on Hip06/Hip07 with DT bindings") Signed-off-by: John Garry --- drivers/bus/hisi_lpc.c | 34 ++++++++++++++++++++++++++++++++-- 1 file changed, 32 insertions(+), 2 deletions(-) -- 2.17.1 diff --git a/drivers/bus/hisi_lpc.c b/drivers/bus/hisi_lpc.c index 6d301aafcad2..0e9f1f141c93 100644 --- a/drivers/bus/hisi_lpc.c +++ b/drivers/bus/hisi_lpc.c @@ -456,6 +456,17 @@ struct hisi_lpc_acpi_cell { size_t pdata_size; }; +static void hisi_lpc_acpi_remove(struct device *hostdev) +{ + struct acpi_device *adev = ACPI_COMPANION(hostdev); + struct acpi_device *child; + + device_for_each_child(hostdev, NULL, hisi_lpc_acpi_remove_subdev); + + list_for_each_entry(child, &adev->children, node) + acpi_device_clear_enumerated(child); +} + /* * hisi_lpc_acpi_probe - probe children for ACPI FW * @hostdev: LPC host device pointer @@ -555,8 +566,7 @@ static int hisi_lpc_acpi_probe(struct device *hostdev) return 0; fail: - device_for_each_child(hostdev, NULL, - hisi_lpc_acpi_remove_subdev); + hisi_lpc_acpi_remove(hostdev); return ret; } @@ -626,6 +636,8 @@ static int hisi_lpc_probe(struct platform_device *pdev) return ret; } + dev_set_drvdata(dev, lpcdev); + io_end = lpcdev->io_host->io_start + lpcdev->io_host->size; dev_info(dev, "registered range [%pa - %pa]\n", &lpcdev->io_host->io_start, &io_end); @@ -633,6 +645,23 @@ static int hisi_lpc_probe(struct platform_device *pdev) return ret; } +static int hisi_lpc_remove(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct acpi_device *acpi_device = ACPI_COMPANION(dev); + struct hisi_lpc_dev *lpcdev = dev_get_drvdata(dev); + struct logic_pio_hwaddr *range = lpcdev->io_host; + + if (acpi_device) + hisi_lpc_acpi_remove(dev); + else + of_platform_depopulate(dev); + + logic_pio_unregister_range(range); + + return 0; +} + static const struct of_device_id hisi_lpc_of_match[] = { { .compatible = "hisilicon,hip06-lpc", }, { .compatible = "hisilicon,hip07-lpc", }, @@ -646,5 +675,6 @@ static struct platform_driver hisi_lpc_driver = { .acpi_match_table = ACPI_PTR(hisi_lpc_acpi_match), }, .probe = hisi_lpc_probe, + .remove = hisi_lpc_remove, }; builtin_platform_driver(hisi_lpc_driver);