From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Nowicki Subject: Re: [PATCH V7 1/8] ACPI: I/O Remapping Table (IORT) initial support Date: Wed, 22 Jun 2016 15:52:36 +0200 Message-ID: <576A9824.1060400@semihalf.com> References: <1466420541-20101-2-git-send-email-tn@semihalf.com> <1466598909-27504-1-git-send-email-tn@semihalf.com> <576A91CC.3000101@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <576A91CC.3000101@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Marc Zyngier , tglx@linutronix.de, jason@lakedaemon.net, rjw@rjwysocki.net, bhelgaas@google.com, lorenzo.pieralisi@arm.com, robert.richter@caviumnetworks.com, shijie.huang@arm.com, Suravee.Suthikulpanit@amd.com, hanjun.guo@linaro.org Cc: al.stone@linaro.org, graeme.gregory@linaro.org, Catalin.Marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, okaya@codeaurora.org, linux-acpi@vger.kernel.org, ddaney.cavm@gmail.com, linux-pci@vger.kernel.org, mw@semihalf.com, andrea.gallo@linaro.org, linux-arm-kernel@lists.infradead.org List-Id: linux-acpi@vger.kernel.org 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 Would you mind to fix that (s/kfree/acpi_os_free) before merging ? Thanks, Tomasz From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751959AbcFVNx6 (ORCPT ); Wed, 22 Jun 2016 09:53:58 -0400 Received: from mail-lf0-f46.google.com ([209.85.215.46]:34947 "EHLO mail-lf0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751146AbcFVNx4 (ORCPT ); Wed, 22 Jun 2016 09:53:56 -0400 Subject: Re: [PATCH V7 1/8] ACPI: I/O Remapping Table (IORT) initial support To: Marc Zyngier , tglx@linutronix.de, jason@lakedaemon.net, rjw@rjwysocki.net, bhelgaas@google.com, lorenzo.pieralisi@arm.com, robert.richter@caviumnetworks.com, shijie.huang@arm.com, Suravee.Suthikulpanit@amd.com, hanjun.guo@linaro.org References: <1466420541-20101-2-git-send-email-tn@semihalf.com> <1466598909-27504-1-git-send-email-tn@semihalf.com> <576A91CC.3000101@arm.com> Cc: al.stone@linaro.org, mw@semihalf.com, graeme.gregory@linaro.org, Catalin.Marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, ddaney.cavm@gmail.com, okaya@codeaurora.org, andrea.gallo@linaro.org, linux-pci@vger.kernel.org From: Tomasz Nowicki Message-ID: <576A9824.1060400@semihalf.com> Date: Wed, 22 Jun 2016 15:52:36 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Firefox/38.0 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: <576A91CC.3000101@arm.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Would you mind to fix that (s/kfree/acpi_os_free) before merging ? Thanks, Tomasz From mboxrd@z Thu Jan 1 00:00:00 1970 From: tn@semihalf.com (Tomasz Nowicki) Date: Wed, 22 Jun 2016 15:52:36 +0200 Subject: [PATCH V7 1/8] ACPI: I/O Remapping Table (IORT) initial support In-Reply-To: <576A91CC.3000101@arm.com> References: <1466420541-20101-2-git-send-email-tn@semihalf.com> <1466598909-27504-1-git-send-email-tn@semihalf.com> <576A91CC.3000101@arm.com> Message-ID: <576A9824.1060400@semihalf.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 Would you mind to fix that (s/kfree/acpi_os_free) before merging ? Thanks, Tomasz