On Mon, Sep 5, 2016 at 10:05 PM, Tomasz Nowicki <tn@xxxxxxxxxxxx> 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 > > IORT support is placed under drivers/acpi/arm64/ new directory due to its > ARM64 specific nature. The code there is considered only for ARM64. > The long term plan is to keep all ARM64 specific tables support > in this place e.g. GTDT table. > > Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx> > Reviewed-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx> > Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> Some cosmetic stuff below. > --- > drivers/acpi/Kconfig | 4 + > drivers/acpi/Makefile | 2 + > drivers/acpi/arm64/Kconfig | 6 ++ > drivers/acpi/arm64/Makefile | 1 + > drivers/acpi/arm64/iort.c | 221 ++++++++++++++++++++++++++++++++++++++++++++ > drivers/acpi/bus.c | 2 + > include/linux/iort.h | 30 ++++++ > 7 files changed, 266 insertions(+) > create mode 100644 drivers/acpi/arm64/Kconfig > create mode 100644 drivers/acpi/arm64/Makefile > create mode 100644 drivers/acpi/arm64/iort.c > create mode 100644 include/linux/iort.h > > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig > index 445ce28..d5c0614 100644 > --- a/drivers/acpi/Kconfig > +++ b/drivers/acpi/Kconfig > @@ -521,4 +521,8 @@ config ACPI_CONFIGFS > userspace. The configurable ACPI groups will be visible under > /config/acpi, assuming configfs is mounted under /config. > > +if ARM64 > +source "drivers/acpi/arm64/Kconfig" > +endif > + > endif # ACPI > diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile > index 5ae9d85..e5ada78 100644 > --- a/drivers/acpi/Makefile > +++ b/drivers/acpi/Makefile > @@ -105,3 +105,5 @@ obj-$(CONFIG_ACPI_CONFIGFS) += acpi_configfs.o > > video-objs += acpi_video.o video_detect.o > obj-y += dptf/ > + > +obj-$(CONFIG_ARM64) += arm64/ > diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig > new file mode 100644 > index 0000000..4616da4 > --- /dev/null > +++ b/drivers/acpi/arm64/Kconfig > @@ -0,0 +1,6 @@ > +# > +# ACPI Configuration for ARM64 > +# > + > +config ACPI_IORT > + bool > diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile > new file mode 100644 > index 0000000..72331f2 > --- /dev/null > +++ b/drivers/acpi/arm64/Makefile > @@ -0,0 +1 @@ > +obj-$(CONFIG_ACPI_IORT) += iort.o > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > new file mode 100644 > index 0000000..82d5e7d > --- /dev/null > +++ b/drivers/acpi/arm64/iort.c > @@ -0,0 +1,221 @@ > +/* > + * 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> Do we need a separate header file for this? > +#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, Please do not break function headers like this. Specifically, the return type and the name should be located in the same line. > + iort_find_node_callback callback, void *context) > +{ > + struct acpi_iort_node *iort_node, *iort_end; > + struct acpi_table_iort *iort; > + int i; > + > + if (!iort_table) > + return NULL; > + > + /* 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; It's better to write this as if (iort_node->type == type && 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"); I'd switch the branches so that the one to be executed on success goes first. Also consider using acpi_status variables for things like this. status = acpi_get_name(adev->handle, ACPI_FULL_PATHNAME, &buffer); if (ACPI_SUCCESS(status)) { is much easier to follow than what you are doing here. > + } else { > + int match; > + > + match = !strcmp(ncomp->device_name, buffer.pointer); > + acpi_os_free(buffer.pointer); > + > + if (match) > + return AE_OK; > + } > + > + break; > + } > + case ACPI_IORT_NODE_PCI_ROOT_COMPLEX: { What is the brace for? > + 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 int > +iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in, u32 *rid_out) > +{ > + /* Single mapping does not care for input id */ > + if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) { > + if (type == ACPI_IORT_NODE_NAMED_COMPONENT || > + type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) { > + *rid_out = map->output_base; > + return 0; > + } > + > + pr_warn(FW_BUG "[map %p] SINGLE MAPPING flag not allowed for node type %d, skipping ID map\n", > + map, type); > + return -ENXIO; > + } > + > + if (rid_in < map->input_base || > + (rid_in >= map->input_base + map->id_count)) > + return -ENXIO; > + > + *rid_out = map->output_base + (rid_in - map->input_base); > + return 0; > +} > + > +static struct acpi_iort_node * > +iort_node_map_rid(struct acpi_iort_node *node, u32 rid_in, > + u32 *rid_out, u8 type) > +{ > + u32 rid = rid_in; > + > + /* Parse the ID mapping tree to find specified node type */ > + while (node) { > + struct acpi_iort_id_mapping *map; > + int i; > + > + if (node->type == type) { > + if (rid_out) > + *rid_out = rid; > + return node; > + } > + > + if (!node->mapping_offset || !node->mapping_count) > + goto fail_map; > + > + map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node, > + node->mapping_offset); > + > + /* Firmware bug! */ > + if (!map->output_reference) { > + pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n", > + node, node->type); > + goto fail_map; > + } > + > + /* Do the RID translation */ > + for (i = 0; i < node->mapping_count; i++, map++) { > + if (!iort_id_map(map, node->type, rid, &rid)) > + break; > + } > + > + if (i == node->mapping_count) > + goto fail_map; > + > + node = ACPI_ADD_PTR(struct acpi_iort_node, iort_table, > + map->output_reference); > + } > + > +fail_map: > + /* Map input RID to output RID unchanged on mapping failure*/ > + if (rid_out) > + *rid_out = rid_in; > + > + return NULL; > +} > + > +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); > +} > + > +void __init acpi_iort_init(void) > +{ > + acpi_status status; > + > + 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); > + } > +} > diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c > index 85b7d07..7ddfbf2 100644 > --- a/drivers/acpi/bus.c > +++ b/drivers/acpi/bus.c > @@ -36,6 +36,7 @@ > #ifdef CONFIG_X86 > #include <asm/mpspec.h> > #endif > +#include <linux/iort.h> > #include <linux/pci.h> > #include <acpi/apei.h> > #include <linux/dmi.h> > @@ -1186,6 +1187,7 @@ static int __init acpi_init(void) > } > > pci_mmcfg_late_init(); > + acpi_iort_init(); > acpi_scan_init(); > acpi_ec_init(); > acpi_debugfs_init(); > diff --git a/include/linux/iort.h b/include/linux/iort.h > new file mode 100644 > index 0000000..f4d5d45 > --- /dev/null > +++ b/include/linux/iort.h If the new file header is necessary, it should be called acpi_iort.h IMO. > @@ -0,0 +1,30 @@ > +/* > + * 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. > + * > + * You should have received a copy of the GNU General Public License along with > + * this program; if not, write to the Free Software Foundation, Inc., 59 Temple > + * Place - Suite 330, Boston, MA 02111-1307 USA. > + */ > + > +#ifndef __IORT_H__ > +#define __IORT_H__ > + > +#include <linux/acpi.h> > + > +#ifdef CONFIG_ACPI_IORT > +void acpi_iort_init(void); > +#else > +static inline void acpi_iort_init(void) { } > +#endif But I'm not really sure what would be wrong with putting this into acpi.h TBH. > + > +#endif /* __IORT_H__ */ > -- > 1.9.1 > Thanks, Rafael -- 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
