From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752073AbcFWBgw (ORCPT ); Wed, 22 Jun 2016 21:36:52 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:65297 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750953AbcFWBgs (ORCPT ); Wed, 22 Jun 2016 21:36:48 -0400 Subject: Re: [PATCH V7 1/8] ACPI: I/O Remapping Table (IORT) initial support To: Marc Zyngier , Tomasz Nowicki , , , , , , , , , References: <1466420541-20101-2-git-send-email-tn@semihalf.com> <1466598909-27504-1-git-send-email-tn@semihalf.com> <576A91CC.3000101@arm.com> <576A9824.1060400@semihalf.com> <576AA603.3080505@arm.com> CC: , , , , , , , , , , , From: Hanjun Guo Message-ID: <576B3CBD.60309@huawei.com> Date: Thu, 23 Jun 2016 09:34:53 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <576AA603.3080505@arm.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.17.188] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A090204.576B3CC9.0160,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 6c7ccdf667bfd0ca9bd2f2958a03de0c Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2016/6/22 22:51, Marc Zyngier wrote: > On 22/06/16 14:52, Tomasz Nowicki wrote: >> On 22.06.2016 15:25, Marc Zyngier wrote: >>> On 22/06/16 13:35, Tomasz Nowicki wrote: >>>> IORT shows representation of IO topology for ARM based systems. >>>> It describes how various components are connected together on >>>> parent-child basis e.g. PCI RC -> SMMU -> ITS. Also see IORT spec. >>>> http://infocenter.arm.com/help/topic/com.arm.doc.den0049b/DEN0049B_IO_Remapping_Table.pdf >>>> >>>> Initial support allows to detect IORT table presence and save its >>>> root pointer obtained through acpi_get_table(). The pointer validity >>>> depends on acpi_gbl_permanent_mmap because if acpi_gbl_permanent_mmap >>>> is not set while using IORT nodes we would dereference unmapped pointers. >>>> >>>> For the aforementioned reason call iort_table_detect() from acpi_init() >>>> which guarantees acpi_gbl_permanent_mmap to be set at that point. >>>> >>>> Add generic helpers which are helpful for scanning and retrieving >>>> information from IORT table content. List of the most important helpers: >>>> - iort_find_dev_node() finds IORT node for a given device >>>> - iort_node_map_rid() maps device RID and returns IORT node which provides >>>> final translation >>>> >>>> Signed-off-by: Tomasz Nowicki >>>> --- >>>> drivers/acpi/Kconfig | 3 + >>>> drivers/acpi/Makefile | 1 + >>>> drivers/acpi/bus.c | 2 + >>>> drivers/acpi/iort.c | 217 ++++++++++++++++++++++++++++++++++++++++++++++++++ >>>> include/linux/iort.h | 30 +++++++ >>>> 5 files changed, 253 insertions(+) >>>> create mode 100644 drivers/acpi/iort.c >>>> create mode 100644 include/linux/iort.h >>>> >>>> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig >>>> index b7e2e77..848471f 100644 >>>> --- a/drivers/acpi/Kconfig >>>> +++ b/drivers/acpi/Kconfig >>>> @@ -57,6 +57,9 @@ config ACPI_SYSTEM_POWER_STATES_SUPPORT >>>> config ACPI_CCA_REQUIRED >>>> bool >>>> >>>> +config IORT_TABLE >>>> + bool >>>> + >>>> config ACPI_DEBUGGER >>>> bool "AML debugger interface" >>>> select ACPI_DEBUG >>>> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile >>>> index 251ce85..c7c9b29 100644 >>>> --- a/drivers/acpi/Makefile >>>> +++ b/drivers/acpi/Makefile >>>> @@ -82,6 +82,7 @@ obj-$(CONFIG_ACPI_CUSTOM_METHOD)+= custom_method.o >>>> obj-$(CONFIG_ACPI_BGRT) += bgrt.o >>>> obj-$(CONFIG_ACPI_CPPC_LIB) += cppc_acpi.o >>>> obj-$(CONFIG_ACPI_DEBUGGER_USER) += acpi_dbg.o >>>> +obj-$(CONFIG_IORT_TABLE) += iort.o >>>> >>>> # processor has its own "processor." module_param namespace >>>> processor-y := processor_driver.o >>>> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c >>>> index 31e8da6..176c17d 100644 >>>> --- a/drivers/acpi/bus.c >>>> +++ b/drivers/acpi/bus.c >>>> @@ -33,6 +33,7 @@ >>>> #ifdef CONFIG_X86 >>>> #include >>>> #endif >>>> +#include >>>> #include >>>> #include >>>> #include >>>> @@ -1118,6 +1119,7 @@ static int __init acpi_init(void) >>>> } >>>> >>>> pci_mmcfg_late_init(); >>>> + iort_table_detect(); >>>> acpi_scan_init(); >>>> acpi_ec_init(); >>>> acpi_debugfs_init(); >>>> diff --git a/drivers/acpi/iort.c b/drivers/acpi/iort.c >>>> new file mode 100644 >>>> index 0000000..fcfa008f >>>> --- /dev/null >>>> +++ b/drivers/acpi/iort.c >>>> @@ -0,0 +1,217 @@ >>>> +/* >>>> + * Copyright (C) 2016, Semihalf >>>> + * Author: Tomasz Nowicki >>>> + * >>>> + * This program is free software; you can redistribute it and/or modify it >>>> + * under the terms and conditions of the GNU General Public License, >>>> + * version 2, as published by the Free Software Foundation. >>>> + * >>>> + * This program is distributed in the hope it will be useful, but WITHOUT >>>> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or >>>> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for >>>> + * more details. >>>> + * >>>> + * This file implements early detection/parsing of I/O mapping >>>> + * reported to OS through firmware via I/O Remapping Table (IORT) >>>> + * IORT document number: ARM DEN 0049A >>>> + */ >>>> + >>>> +#define pr_fmt(fmt) "ACPI: IORT: " fmt >>>> + >>>> +#include >>>> +#include >>>> +#include >>>> + >>>> +typedef acpi_status (*iort_find_node_callback) >>>> + (struct acpi_iort_node *node, void *context); >>>> + >>>> +/* Root pointer to the mapped IORT table */ >>>> +static struct acpi_table_header *iort_table; >>>> + >>>> +static struct acpi_iort_node * >>>> +iort_scan_node(enum acpi_iort_node_type type, >>>> + iort_find_node_callback callback, void *context) >>>> +{ >>>> + struct acpi_iort_node *iort_node, *iort_end; >>>> + struct acpi_table_iort *iort; >>>> + int i; >>>> + >>>> + /* Get the first IORT node */ >>>> + iort = (struct acpi_table_iort *)iort_table; >>>> + iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort, >>>> + iort->node_offset); >>>> + iort_end = ACPI_ADD_PTR(struct acpi_iort_node, iort_table, >>>> + iort_table->length); >>>> + >>>> + for (i = 0; i < iort->node_count; i++) { >>>> + if (WARN_TAINT(iort_node >= iort_end, TAINT_FIRMWARE_WORKAROUND, >>>> + "IORT node pointer overflows, bad table!\n")) >>>> + return NULL; >>>> + >>>> + if (iort_node->type == type) { >>>> + if (ACPI_SUCCESS(callback(iort_node, context))) >>>> + return iort_node; >>>> + } >>>> + >>>> + iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node, >>>> + iort_node->length); >>>> + } >>>> + >>>> + return NULL; >>>> +} >>>> + >>>> +static acpi_status >>>> +iort_match_node_callback(struct acpi_iort_node *node, void *context) >>>> +{ >>>> + struct device *dev = context; >>>> + >>>> + switch (node->type) { >>>> + case ACPI_IORT_NODE_NAMED_COMPONENT: { >>>> + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; >>>> + struct acpi_device *adev = to_acpi_device_node(dev->fwnode); >>>> + struct acpi_iort_named_component *ncomp; >>>> + >>>> + if (!adev) >>>> + break; >>>> + >>>> + ncomp = (struct acpi_iort_named_component *)node->node_data; >>>> + >>>> + if (ACPI_FAILURE(acpi_get_name(adev->handle, >>>> + ACPI_FULL_PATHNAME, &buffer))) { >>>> + dev_warn(dev, "Can't get device full path name\n"); >>>> + } else { >>>> + int match; >>>> + >>>> + match = !strcmp(ncomp->device_name, buffer.pointer); >>>> + kfree(buffer.pointer); >>> Why did you change this to a naked kfree? The ACPI code clearly states: >>> >>> /* >>> * Allocate a new buffer. We directectly call acpi_os_allocate here to >>> * purposefully bypass the (optionally enabled) internal allocation >>> * tracking mechanism since we only want to track internal >>> * allocations. Note: The caller should use acpi_os_free to free this >>> * buffer created via ACPI_ALLOCATE_BUFFER. >>> */ >> Yes we should use symmetric free function to acpi_os_allocate here, >> which means acpi_os_free should be used here. >> >> My main motivation was to free buffer.pointer instead of &buffer It needs to be free buffer.pointer. >> >> Would you mind to fix that (s/kfree/acpi_os_free) before merging ? > Sure. I tracked Marc's tree on git.kernel.org, it's acpi_os_free(buffer.pointer) there so my worry is gone :) Thanks Hanjun