From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Nowicki Subject: Re: [PATCH V6 1/7] ACPI: I/O Remapping Table (IORT) initial support Date: Wed, 15 Jun 2016 15:29:26 +0200 Message-ID: <57615836.9090104@semihalf.com> References: <1465828873-23498-1-git-send-email-tn@semihalf.com> <1465828873-23498-2-git-send-email-tn@semihalf.com> <20160615110427.GD30560@red-moon> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wm0-f46.google.com ([74.125.82.46]:38889 "EHLO mail-wm0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932732AbcFON3a (ORCPT ); Wed, 15 Jun 2016 09:29:30 -0400 Received: by mail-wm0-f46.google.com with SMTP id m124so36613443wme.1 for ; Wed, 15 Jun 2016 06:29:30 -0700 (PDT) In-Reply-To: <20160615110427.GD30560@red-moon> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Lorenzo Pieralisi Cc: marc.zyngier@arm.com, tglx@linutronix.de, jason@lakedaemon.net, rjw@rjwysocki.net, bhelgaas@google.com, robert.richter@caviumnetworks.com, shijie.huang@arm.com, Suravee.Suthikulpanit@amd.com, hanjun.guo@linaro.org, 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 On 15.06.2016 13:04, Lorenzo Pieralisi wrote: > On Mon, Jun 13, 2016 at 04:41:07PM +0200, 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. >> >> Initial support allows to: >> - register ITS MSI chip along with ITS translation ID and domain token >> - deregister ITS MSI chip based on ITS translation ID >> - find registered domain token based on ITS translation ID >> - map MSI RID for a device >> - find domain token for a device >> >> Signed-off-by: Tomasz Nowicki >> --- >> drivers/acpi/Kconfig | 3 + >> drivers/acpi/Makefile | 1 + >> drivers/acpi/iort.c | 386 ++++++++++++++++++++++++++++++++++++++++++++++++++ >> include/linux/iort.h | 38 +++++ >> 4 files changed, 428 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 f98c328..111dd50 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 632e81f..0390f27 100644 >> --- a/drivers/acpi/Makefile >> +++ b/drivers/acpi/Makefile >> @@ -83,6 +83,7 @@ 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/iort.c b/drivers/acpi/iort.c >> new file mode 100644 >> index 0000000..5bccbc8 >> --- /dev/null >> +++ b/drivers/acpi/iort.c >> @@ -0,0 +1,386 @@ >> +/* >> + * 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 >> +#include >> +#include >> + >> +struct iort_its_msi_chip { >> + struct list_head list; >> + struct fwnode_handle *fw_node; >> + u32 translation_id; >> +}; >> + >> +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; > > A question to be sorted out: > > We assume we can rely on the iort_table pointer, obtained through > acpi_get_table(), since we assume acpi_glb_permanent_mmap is set (?), > correct ? > > x86 DMAR code seems to rely on that (without even checking > acpi_gbl_permanent_mmap) and this has consequences on when > we can really start parsing IORT entries through this patch > (because if acpi_gbl_permanent_mmap is not set while using > IORT nodes we would dereference unmapped pointers). > > @Rafael: can you confirm that's the right approach ? > >> +static LIST_HEAD(iort_msi_chip_list); >> +static DEFINE_SPINLOCK(iort_msi_chip_lock); >> + >> +/** >> + * iort_register_domain_token() - register domain token and related ITS ID >> + * to the list from where we can get it back later on. >> + * @translation_id: ITS ID. >> + * @token: Domain token. >> + * >> + * Returns: 0 on success, -ENOMEM if no memory when allocating list element >> + */ >> +int iort_register_domain_token(int trans_id, struct fwnode_handle *fw_node) >> +{ >> + struct iort_its_msi_chip *its_msi_chip; >> + >> + its_msi_chip = kzalloc(sizeof(*its_msi_chip), GFP_KERNEL); >> + if (!its_msi_chip) >> + return -ENOMEM; >> + >> + its_msi_chip->fw_node = fw_node; >> + its_msi_chip->translation_id = trans_id; >> + >> + spin_lock(&iort_msi_chip_lock); >> + list_add(&its_msi_chip->list, &iort_msi_chip_list); >> + spin_unlock(&iort_msi_chip_lock); >> + >> + return 0; >> +} >> + >> +/** >> + * iort_deregister_domain_token() - Deregister domain token based on ITS ID >> + * @translation_id: ITS ID. >> + * >> + * Returns: none. >> + */ >> +void iort_deregister_domain_token(int trans_id) >> +{ >> + struct iort_its_msi_chip *its_msi_chip, *t; >> + >> + spin_lock(&iort_msi_chip_lock); >> + list_for_each_entry_safe(its_msi_chip, t, &iort_msi_chip_list, list) { >> + if (its_msi_chip->translation_id == trans_id) { >> + list_del(&its_msi_chip->list); >> + kfree(its_msi_chip); >> + break; >> + } >> + } >> + spin_unlock(&iort_msi_chip_lock); >> +} >> + >> +/** >> + * iort_find_domain_token() - Find domain token based on given ITS ID >> + * @translation_id: ITS ID. >> + * >> + * Returns: domain token when find on the list, NULL otherwise >> + */ >> +struct fwnode_handle *iort_find_domain_token(int trans_id) >> +{ >> + struct fwnode_handle *fw_node = NULL; >> + struct iort_its_msi_chip *its_msi_chip; >> + >> + spin_lock(&iort_msi_chip_lock); >> + list_for_each_entry(its_msi_chip, &iort_msi_chip_list, list) { >> + if (its_msi_chip->translation_id == trans_id) { >> + fw_node = its_msi_chip->fw_node; >> + break; >> + } >> + } >> + spin_unlock(&iort_msi_chip_lock); >> + >> + return fw_node; >> +} > > You are lumping irq_domain/MSI/ITS code and basic IORT (core) support > in one patch, I would split them in two. OK > >> +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"); >> + break; >> + } >> + >> + if (!strcmp(ncomp->device_name, (char *)buffer.pointer)) >> + return AE_OK; >> + >> + break; >> + } >> + case ACPI_IORT_NODE_PCI_ROOT_COMPLEX: { >> + struct acpi_iort_root_complex *pci_rc; >> + struct pci_bus *bus; >> + >> + bus = to_pci_bus(dev); >> + pci_rc = (struct acpi_iort_root_complex *)node->node_data; >> + >> + /* >> + * It is assumed that PCI segment numbers maps one-to-one >> + * with root complexes. Each segment number can represent only >> + * one root complex. >> + */ >> + if (pci_rc->pci_segment_number == pci_domain_nr(bus)) >> + return AE_OK; >> + >> + break; >> + } >> + } >> + >> + return AE_NOT_FOUND; >> +} >> + >> +static struct acpi_iort_node * >> +iort_node_map_rid(struct acpi_iort_node *node, u32 rid_in, >> + u32 *rid_out, u8 type) >> +{ >> + >> + if (!node) >> + goto out; > > Mmmm..can you explain to me what's the logic here ? As Marc pointed out, the logic is not consistent now. iort_node_map_rid IMO should map rid and return parent node which provide final translation e.g. IORT or SMMU node. In case of any error it should return NULL and provide 1:1 RID mapping (rid_out = rid_in). > >> + /* Go upstream */ >> + while (node->type != type) { >> + struct acpi_iort_id_mapping *id; >> + int i, found = 0; >> + >> + /* Exit when no mapping array */ >> + if (!node->mapping_offset || !node->mapping_count) >> + return NULL; >> + >> + id = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node, >> + node->mapping_offset); >> + >> + for (i = 0, found = 0; i < node->mapping_count; i++, id++) { >> + /* >> + * Single mapping is not translation rule, >> + * lets move on for this case >> + */ >> + if (id->flags & ACPI_IORT_ID_SINGLE_MAPPING) { >> + if (node->type != ACPI_IORT_NODE_SMMU) { > > This is wrong (ie node can be an SMMU v3 and an ITS group). Right, ITS will never get to this point but SMMU v3 can. I will invert condition to: if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT || node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) { [...] } > >> + rid_in = id->output_base; >> + found = 1; >> + break; >> + } >> + >> + pr_warn(FW_BUG "[node %p type %d] SINGLE MAPPING flag not allowed for SMMU node, skipping ID map\n", >> + node, node->type); >> + continue; >> + } >> + >> + if (rid_in < id->input_base || >> + (rid_in > id->input_base + id->id_count)) >> + continue; >> + >> + rid_in = id->output_base + (rid_in - id->input_base); >> + found = 1; >> + break; >> + } >> + > > This inner loop is getting too complicated (and this function with > it) to my taste. Is it reasonable to factor it out in a separate > function ? I will try to put it to another fundtion. > >> + if (!found) >> + return NULL; >> + >> + /* Firmware bug! */ >> + if (!id->output_reference) { >> + pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n", >> + node, node->type); >> + return NULL; >> + } >> + >> + node = ACPI_ADD_PTR(struct acpi_iort_node, iort_table, >> + id->output_reference); >> + } >> + >> +out: >> + if (rid_out) >> + *rid_out = rid_in; >> + return node; >> +} >> + >> +static struct acpi_iort_node * >> +iort_find_dev_node(struct device *dev) >> +{ >> + struct pci_bus *pbus; >> + >> + if (!dev_is_pci(dev)) >> + return iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT, >> + iort_match_node_callback, dev); >> + >> + /* Find a PCI root bus */ >> + pbus = to_pci_dev(dev)->bus; >> + while (!pci_is_root_bus(pbus)) >> + pbus = pbus->parent; >> + >> + return iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX, >> + iort_match_node_callback, &pbus->dev); >> +} >> + >> +/** >> + * iort_msi_map_rid() - Map a MSI requester ID for a device >> + * @dev: The device for which the mapping is to be done. >> + * @req_id: The device requester ID. >> + * >> + * Returns: mapped MSI RID on success, input requester ID otherwise >> + */ >> +u32 iort_msi_map_rid(struct device *dev, u32 req_id) >> +{ >> + struct acpi_iort_node *node; >> + u32 dev_id; >> + >> + if (!iort_table) >> + return req_id; >> + >> + node = iort_find_dev_node(dev); >> + if (!node) { >> + dev_err(dev, "can't find related IORT node\n"); >> + return req_id; >> + } >> + >> + if (!iort_node_map_rid(node, req_id, &dev_id, >> + ACPI_IORT_NODE_ITS_GROUP)) >> + return req_id; >> + >> + return dev_id; >> +} >> + >> +/** >> + * iort_dev_find_its_id() - Find the ITS identifier for a device >> + * @dev: The device. >> + * @idx: Index of the ITS identifier list. >> + * @its_id: ITS identifier. >> + * >> + * Returns: 0 on success, appropriate error value otherwise >> + */ >> +static int >> +iort_dev_find_its_id(struct device *dev, u32 req_id, unsigned int idx, >> + int *its_id) >> +{ >> + struct acpi_iort_its_group *its; >> + struct acpi_iort_node *node; >> + >> + node = iort_find_dev_node(dev); >> + if (!node) { >> + dev_err(dev, "can't find related IORT node\n"); >> + return -ENXIO; >> + } >> + >> + node = iort_node_map_rid(node, req_id, NULL, ACPI_IORT_NODE_ITS_GROUP); >> + if (!node) { >> + dev_err(dev, "can't find related ITS node\n"); >> + return -ENXIO; >> + } >> + >> + /* Move to ITS specific data */ >> + its = (struct acpi_iort_its_group *)node->node_data; >> + if (idx > its->its_count) { >> + dev_err(dev, "requested ITS ID index [%d] is greater than available [%d]\n", >> + idx, its->its_count); >> + return -ENXIO; >> + } >> + >> + *its_id = its->identifiers[idx]; >> + return 0; >> +} >> + >> +/** >> + * iort_get_device_domain() - Find MSI domain related to a device >> + * @dev: The device. >> + * @req_id: Requester ID for the device. >> + * >> + * Returns: the MSI domain for this device, NULL otherwise >> + */ >> +struct irq_domain * >> +iort_get_device_domain(struct device *dev, u32 req_id) >> +{ >> + static struct fwnode_handle *handle; >> + int its_id; >> + >> + if (!iort_table) >> + return NULL; >> + >> + if (iort_dev_find_its_id(dev, req_id, 0, &its_id)) > ^ > This is supposed to be an index in the ITS identifiers list and it is > always 0 (I *guess* that's because _any_ identifier in that group > would do but I want to undestand why), please explain :) Well, we do not have infrastructure to decide which index would be better and since any index is fine from the iort_get_device_domain() perspecitive, I just used 0 here. > > One reason more why I think you should split this patch in two > so that it becomes easier for Marc to review the ITS specific > bits: > > - IORT core > - ITS/MSI IORT handling > >> + return NULL; >> + >> + handle = iort_find_domain_token(its_id); >> + if (!handle) >> + return NULL; >> + >> + return irq_find_matching_fwnode(handle, DOMAIN_BUS_PCI_MSI); >> +} >> + >> +static int __init iort_table_detect(void) >> +{ >> + acpi_status status; >> + >> + if (acpi_disabled) >> + return -ENODEV; >> + >> + status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table); >> + if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) { >> + const char *msg = acpi_format_exception(status); >> + pr_err("Failed to get table, %s\n", msg); >> + return -EINVAL; >> + } >> + >> + return 0; >> +} >> +arch_initcall(iort_table_detect); > > To prevent calling it from an initcall we can call it from arch > code (but careful about the iort_table pointer validity, see above). > > We should settle the iort_table pointer validity first, everything > else depends on it. Yes. Thanks, Tomasz From mboxrd@z Thu Jan 1 00:00:00 1970 From: tn@semihalf.com (Tomasz Nowicki) Date: Wed, 15 Jun 2016 15:29:26 +0200 Subject: [PATCH V6 1/7] ACPI: I/O Remapping Table (IORT) initial support In-Reply-To: <20160615110427.GD30560@red-moon> References: <1465828873-23498-1-git-send-email-tn@semihalf.com> <1465828873-23498-2-git-send-email-tn@semihalf.com> <20160615110427.GD30560@red-moon> Message-ID: <57615836.9090104@semihalf.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 15.06.2016 13:04, Lorenzo Pieralisi wrote: > On Mon, Jun 13, 2016 at 04:41:07PM +0200, 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. >> >> Initial support allows to: >> - register ITS MSI chip along with ITS translation ID and domain token >> - deregister ITS MSI chip based on ITS translation ID >> - find registered domain token based on ITS translation ID >> - map MSI RID for a device >> - find domain token for a device >> >> Signed-off-by: Tomasz Nowicki >> --- >> drivers/acpi/Kconfig | 3 + >> drivers/acpi/Makefile | 1 + >> drivers/acpi/iort.c | 386 ++++++++++++++++++++++++++++++++++++++++++++++++++ >> include/linux/iort.h | 38 +++++ >> 4 files changed, 428 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 f98c328..111dd50 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 632e81f..0390f27 100644 >> --- a/drivers/acpi/Makefile >> +++ b/drivers/acpi/Makefile >> @@ -83,6 +83,7 @@ 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/iort.c b/drivers/acpi/iort.c >> new file mode 100644 >> index 0000000..5bccbc8 >> --- /dev/null >> +++ b/drivers/acpi/iort.c >> @@ -0,0 +1,386 @@ >> +/* >> + * 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 >> +#include >> +#include >> + >> +struct iort_its_msi_chip { >> + struct list_head list; >> + struct fwnode_handle *fw_node; >> + u32 translation_id; >> +}; >> + >> +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; > > A question to be sorted out: > > We assume we can rely on the iort_table pointer, obtained through > acpi_get_table(), since we assume acpi_glb_permanent_mmap is set (?), > correct ? > > x86 DMAR code seems to rely on that (without even checking > acpi_gbl_permanent_mmap) and this has consequences on when > we can really start parsing IORT entries through this patch > (because if acpi_gbl_permanent_mmap is not set while using > IORT nodes we would dereference unmapped pointers). > > @Rafael: can you confirm that's the right approach ? > >> +static LIST_HEAD(iort_msi_chip_list); >> +static DEFINE_SPINLOCK(iort_msi_chip_lock); >> + >> +/** >> + * iort_register_domain_token() - register domain token and related ITS ID >> + * to the list from where we can get it back later on. >> + * @translation_id: ITS ID. >> + * @token: Domain token. >> + * >> + * Returns: 0 on success, -ENOMEM if no memory when allocating list element >> + */ >> +int iort_register_domain_token(int trans_id, struct fwnode_handle *fw_node) >> +{ >> + struct iort_its_msi_chip *its_msi_chip; >> + >> + its_msi_chip = kzalloc(sizeof(*its_msi_chip), GFP_KERNEL); >> + if (!its_msi_chip) >> + return -ENOMEM; >> + >> + its_msi_chip->fw_node = fw_node; >> + its_msi_chip->translation_id = trans_id; >> + >> + spin_lock(&iort_msi_chip_lock); >> + list_add(&its_msi_chip->list, &iort_msi_chip_list); >> + spin_unlock(&iort_msi_chip_lock); >> + >> + return 0; >> +} >> + >> +/** >> + * iort_deregister_domain_token() - Deregister domain token based on ITS ID >> + * @translation_id: ITS ID. >> + * >> + * Returns: none. >> + */ >> +void iort_deregister_domain_token(int trans_id) >> +{ >> + struct iort_its_msi_chip *its_msi_chip, *t; >> + >> + spin_lock(&iort_msi_chip_lock); >> + list_for_each_entry_safe(its_msi_chip, t, &iort_msi_chip_list, list) { >> + if (its_msi_chip->translation_id == trans_id) { >> + list_del(&its_msi_chip->list); >> + kfree(its_msi_chip); >> + break; >> + } >> + } >> + spin_unlock(&iort_msi_chip_lock); >> +} >> + >> +/** >> + * iort_find_domain_token() - Find domain token based on given ITS ID >> + * @translation_id: ITS ID. >> + * >> + * Returns: domain token when find on the list, NULL otherwise >> + */ >> +struct fwnode_handle *iort_find_domain_token(int trans_id) >> +{ >> + struct fwnode_handle *fw_node = NULL; >> + struct iort_its_msi_chip *its_msi_chip; >> + >> + spin_lock(&iort_msi_chip_lock); >> + list_for_each_entry(its_msi_chip, &iort_msi_chip_list, list) { >> + if (its_msi_chip->translation_id == trans_id) { >> + fw_node = its_msi_chip->fw_node; >> + break; >> + } >> + } >> + spin_unlock(&iort_msi_chip_lock); >> + >> + return fw_node; >> +} > > You are lumping irq_domain/MSI/ITS code and basic IORT (core) support > in one patch, I would split them in two. OK > >> +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"); >> + break; >> + } >> + >> + if (!strcmp(ncomp->device_name, (char *)buffer.pointer)) >> + return AE_OK; >> + >> + break; >> + } >> + case ACPI_IORT_NODE_PCI_ROOT_COMPLEX: { >> + struct acpi_iort_root_complex *pci_rc; >> + struct pci_bus *bus; >> + >> + bus = to_pci_bus(dev); >> + pci_rc = (struct acpi_iort_root_complex *)node->node_data; >> + >> + /* >> + * It is assumed that PCI segment numbers maps one-to-one >> + * with root complexes. Each segment number can represent only >> + * one root complex. >> + */ >> + if (pci_rc->pci_segment_number == pci_domain_nr(bus)) >> + return AE_OK; >> + >> + break; >> + } >> + } >> + >> + return AE_NOT_FOUND; >> +} >> + >> +static struct acpi_iort_node * >> +iort_node_map_rid(struct acpi_iort_node *node, u32 rid_in, >> + u32 *rid_out, u8 type) >> +{ >> + >> + if (!node) >> + goto out; > > Mmmm..can you explain to me what's the logic here ? As Marc pointed out, the logic is not consistent now. iort_node_map_rid IMO should map rid and return parent node which provide final translation e.g. IORT or SMMU node. In case of any error it should return NULL and provide 1:1 RID mapping (rid_out = rid_in). > >> + /* Go upstream */ >> + while (node->type != type) { >> + struct acpi_iort_id_mapping *id; >> + int i, found = 0; >> + >> + /* Exit when no mapping array */ >> + if (!node->mapping_offset || !node->mapping_count) >> + return NULL; >> + >> + id = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node, >> + node->mapping_offset); >> + >> + for (i = 0, found = 0; i < node->mapping_count; i++, id++) { >> + /* >> + * Single mapping is not translation rule, >> + * lets move on for this case >> + */ >> + if (id->flags & ACPI_IORT_ID_SINGLE_MAPPING) { >> + if (node->type != ACPI_IORT_NODE_SMMU) { > > This is wrong (ie node can be an SMMU v3 and an ITS group). Right, ITS will never get to this point but SMMU v3 can. I will invert condition to: if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT || node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) { [...] } > >> + rid_in = id->output_base; >> + found = 1; >> + break; >> + } >> + >> + pr_warn(FW_BUG "[node %p type %d] SINGLE MAPPING flag not allowed for SMMU node, skipping ID map\n", >> + node, node->type); >> + continue; >> + } >> + >> + if (rid_in < id->input_base || >> + (rid_in > id->input_base + id->id_count)) >> + continue; >> + >> + rid_in = id->output_base + (rid_in - id->input_base); >> + found = 1; >> + break; >> + } >> + > > This inner loop is getting too complicated (and this function with > it) to my taste. Is it reasonable to factor it out in a separate > function ? I will try to put it to another fundtion. > >> + if (!found) >> + return NULL; >> + >> + /* Firmware bug! */ >> + if (!id->output_reference) { >> + pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n", >> + node, node->type); >> + return NULL; >> + } >> + >> + node = ACPI_ADD_PTR(struct acpi_iort_node, iort_table, >> + id->output_reference); >> + } >> + >> +out: >> + if (rid_out) >> + *rid_out = rid_in; >> + return node; >> +} >> + >> +static struct acpi_iort_node * >> +iort_find_dev_node(struct device *dev) >> +{ >> + struct pci_bus *pbus; >> + >> + if (!dev_is_pci(dev)) >> + return iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT, >> + iort_match_node_callback, dev); >> + >> + /* Find a PCI root bus */ >> + pbus = to_pci_dev(dev)->bus; >> + while (!pci_is_root_bus(pbus)) >> + pbus = pbus->parent; >> + >> + return iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX, >> + iort_match_node_callback, &pbus->dev); >> +} >> + >> +/** >> + * iort_msi_map_rid() - Map a MSI requester ID for a device >> + * @dev: The device for which the mapping is to be done. >> + * @req_id: The device requester ID. >> + * >> + * Returns: mapped MSI RID on success, input requester ID otherwise >> + */ >> +u32 iort_msi_map_rid(struct device *dev, u32 req_id) >> +{ >> + struct acpi_iort_node *node; >> + u32 dev_id; >> + >> + if (!iort_table) >> + return req_id; >> + >> + node = iort_find_dev_node(dev); >> + if (!node) { >> + dev_err(dev, "can't find related IORT node\n"); >> + return req_id; >> + } >> + >> + if (!iort_node_map_rid(node, req_id, &dev_id, >> + ACPI_IORT_NODE_ITS_GROUP)) >> + return req_id; >> + >> + return dev_id; >> +} >> + >> +/** >> + * iort_dev_find_its_id() - Find the ITS identifier for a device >> + * @dev: The device. >> + * @idx: Index of the ITS identifier list. >> + * @its_id: ITS identifier. >> + * >> + * Returns: 0 on success, appropriate error value otherwise >> + */ >> +static int >> +iort_dev_find_its_id(struct device *dev, u32 req_id, unsigned int idx, >> + int *its_id) >> +{ >> + struct acpi_iort_its_group *its; >> + struct acpi_iort_node *node; >> + >> + node = iort_find_dev_node(dev); >> + if (!node) { >> + dev_err(dev, "can't find related IORT node\n"); >> + return -ENXIO; >> + } >> + >> + node = iort_node_map_rid(node, req_id, NULL, ACPI_IORT_NODE_ITS_GROUP); >> + if (!node) { >> + dev_err(dev, "can't find related ITS node\n"); >> + return -ENXIO; >> + } >> + >> + /* Move to ITS specific data */ >> + its = (struct acpi_iort_its_group *)node->node_data; >> + if (idx > its->its_count) { >> + dev_err(dev, "requested ITS ID index [%d] is greater than available [%d]\n", >> + idx, its->its_count); >> + return -ENXIO; >> + } >> + >> + *its_id = its->identifiers[idx]; >> + return 0; >> +} >> + >> +/** >> + * iort_get_device_domain() - Find MSI domain related to a device >> + * @dev: The device. >> + * @req_id: Requester ID for the device. >> + * >> + * Returns: the MSI domain for this device, NULL otherwise >> + */ >> +struct irq_domain * >> +iort_get_device_domain(struct device *dev, u32 req_id) >> +{ >> + static struct fwnode_handle *handle; >> + int its_id; >> + >> + if (!iort_table) >> + return NULL; >> + >> + if (iort_dev_find_its_id(dev, req_id, 0, &its_id)) > ^ > This is supposed to be an index in the ITS identifiers list and it is > always 0 (I *guess* that's because _any_ identifier in that group > would do but I want to undestand why), please explain :) Well, we do not have infrastructure to decide which index would be better and since any index is fine from the iort_get_device_domain() perspecitive, I just used 0 here. > > One reason more why I think you should split this patch in two > so that it becomes easier for Marc to review the ITS specific > bits: > > - IORT core > - ITS/MSI IORT handling > >> + return NULL; >> + >> + handle = iort_find_domain_token(its_id); >> + if (!handle) >> + return NULL; >> + >> + return irq_find_matching_fwnode(handle, DOMAIN_BUS_PCI_MSI); >> +} >> + >> +static int __init iort_table_detect(void) >> +{ >> + acpi_status status; >> + >> + if (acpi_disabled) >> + return -ENODEV; >> + >> + status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table); >> + if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) { >> + const char *msg = acpi_format_exception(status); >> + pr_err("Failed to get table, %s\n", msg); >> + return -EINVAL; >> + } >> + >> + return 0; >> +} >> +arch_initcall(iort_table_detect); > > To prevent calling it from an initcall we can call it from arch > code (but careful about the iort_table pointer validity, see above). > > We should settle the iort_table pointer validity first, everything > else depends on it. Yes. Thanks, Tomasz