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. */ Thanks, 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
