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 <tn@xxxxxxxxxxxx> >>> --- >>> 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 <asm/mpspec.h> >>> #endif >>> +#include <linux/iort.h> >>> #include <linux/pci.h> >>> #include <acpi/apei.h> >>> #include <linux/dmi.h> >>> @@ -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 <tn@xxxxxxxxxxxx> >>> + * >>> + * 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 <linux/iort.h> >>> +#include <linux/kernel.h> >>> +#include <linux/pci.h> >>> + >>> +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 ? Sure. M. -- Jazz is not dead. It just smells funny... -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
