From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dennis Chen Subject: Re: [PATCH V8 1/8] ACPI: I/O Remapping Table (IORT) initial support Date: Thu, 18 Aug 2016 18:55:50 +0800 Message-ID: <20160818105549.GB20404@arm.com> References: <1470909998-16710-1-git-send-email-tn@semihalf.com> <1470909998-16710-2-git-send-email-tn@semihalf.com> Mime-Version: 1.0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <1470909998-16710-2-git-send-email-tn@semihalf.com> Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: Tomasz Nowicki Cc: marc.zyngier@arm.com, tglx@linutronix.de, jason@lakedaemon.net, rjw@rjwysocki.net, helgaas@kernel.org, rafael@kernel.org, Lorenzo.Pieralisi@arm.com, will.deacon@arm.com, catalin.marinas@arm.com, hanjun.guo@linaro.org, shijie.huang@arm.com, robert.richter@caviumnetworks.com, mw@semihalf.com, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linaro-acpi@lists.linaro.org, andrea.gallo@linaro.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, al.stone@linaro.org, graeme.gregory@linaro.org, ddaney.cavm@gmail.com, okaya@codeaurora.org, nd@arm.com List-Id: linux-acpi@vger.kernel.org Hi Tomasz, On Thu, Aug 11, 2016 at 12:06:31PM +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. > http://infocenter.arm.com/help/topic/com.arm.doc.den0049b/DEN0049B_IO_Rem= apping_Table.pdf >=20 > 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. >=20 > For the aforementioned reason call iort_table_detect() from acpi_init() > which guarantees acpi_gbl_permanent_mmap to be set at that point. >=20 > 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 provide= s > final translation >=20 > 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. >=20 > Signed-off-by: Tomasz Nowicki > Reviewed-by: Hanjun Guo > --- > drivers/acpi/Kconfig | 5 + > drivers/acpi/Makefile | 2 + > drivers/acpi/arm64/Kconfig | 6 ++ > drivers/acpi/arm64/Makefile | 1 + > drivers/acpi/arm64/iort.c | 218 ++++++++++++++++++++++++++++++++++++++= ++++++ > drivers/acpi/bus.c | 2 + > include/linux/iort.h | 30 ++++++ > 7 files changed, 264 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 >=20 > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig > index 445ce28..6cef2d1 100644 > --- a/drivers/acpi/Kconfig > +++ b/drivers/acpi/Kconfig > @@ -521,4 +521,9 @@ config ACPI_CONFIGFS > =09 userspace. The configurable ACPI groups will be visible under > =09 /config/acpi, assuming configfs is mounted under /config. > =20 > +if ARM64 > +source "drivers/acpi/arm64/Kconfig" > + > +endif > + > endif=09# 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-$(CONFIG_ACPI_CONFIGFS)=09+=3D acpi_configfs.o > =20 > video-objs=09=09=09+=3D acpi_video.o video_detect.o > obj-y=09=09=09=09+=3D dptf/ > + > +obj-$(CONFIG_ARM64)=09=09+=3D arm64/ > diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig > new file mode 100644 > index 0000000..fc818dc > --- /dev/null > +++ b/drivers/acpi/arm64/Kconfig > @@ -0,0 +1,6 @@ > +# > +# ACPI Configuration for ARM64 > +# > + > +config IORT_TABLE > +=09bool > diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile > new file mode 100644 > index 0000000..d01be6f > --- /dev/null > +++ b/drivers/acpi/arm64/Makefile > @@ -0,0 +1 @@ > +obj-$(CONFIG_IORT_TABLE) =09+=3D iort.o > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > new file mode 100644 > index 0000000..f89056e > --- /dev/null > +++ b/drivers/acpi/arm64/iort.c > @@ -0,0 +1,218 @@ > +/* > + * Copyright (C) 2016, Semihalf > + *=09Author: 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 WITHOU= T > + * 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)=09"ACPI: IORT: " fmt > + > +#include > +#include > +#include > + > +typedef acpi_status (*iort_find_node_callback) > +=09(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, > +=09 iort_find_node_callback callback, void *context) > +{ > +=09struct acpi_iort_node *iort_node, *iort_end; > +=09struct acpi_table_iort *iort; > +=09int i; > + > +=09/* Get the first IORT node */ > +=09iort =3D (struct acpi_table_iort *)iort_table; > Here, the same as I comments on Lorenzo's patch. If IORT is missed in the f= irmware, then iort_table will be NULL, result in kernel panic in the codes followed. Thanks, Dennis > +=09iort_node =3D ACPI_ADD_PTR(struct acpi_iort_node, iort, > +=09=09=09=09 iort->node_offset); > +=09iort_end =3D ACPI_ADD_PTR(struct acpi_iort_node, iort_table, > +=09=09=09=09iort_table->length); > + > +=09for (i =3D 0; i < iort->node_count; i++) { > +=09=09if (WARN_TAINT(iort_node >=3D iort_end, TAINT_FIRMWARE_WORKAROUND, > +=09=09=09 "IORT node pointer overflows, bad table!\n")) > +=09=09=09return NULL; > + > +=09=09if (iort_node->type =3D=3D type) { > +=09=09=09if (ACPI_SUCCESS(callback(iort_node, context))) > +=09=09=09=09return iort_node; > +=09=09} > + > +=09=09iort_node =3D ACPI_ADD_PTR(struct acpi_iort_node, iort_node, > +=09=09=09=09=09 iort_node->length); > +=09} > + > +=09return NULL; > +} > + > +static acpi_status > +iort_match_node_callback(struct acpi_iort_node *node, void *context) > +{ > +=09struct device *dev =3D context; > + > +=09switch (node->type) { > +=09case ACPI_IORT_NODE_NAMED_COMPONENT: { > +=09=09struct acpi_buffer buffer =3D { ACPI_ALLOCATE_BUFFER, NULL }; > +=09=09struct acpi_device *adev =3D to_acpi_device_node(dev->fwnode); > +=09=09struct acpi_iort_named_component *ncomp; > + > +=09=09if (!adev) > +=09=09=09break; > + > +=09=09ncomp =3D (struct acpi_iort_named_component *)node->node_data; > + > +=09=09if (ACPI_FAILURE(acpi_get_name(adev->handle, > +=09=09=09=09=09 ACPI_FULL_PATHNAME, &buffer))) { > +=09=09=09dev_warn(dev, "Can't get device full path name\n"); > +=09=09} else { > +=09=09=09int match; > + > +=09=09=09match =3D !strcmp(ncomp->device_name, buffer.pointer); > +=09=09=09acpi_os_free(buffer.pointer); > + > +=09=09=09if (match) > +=09=09=09=09return AE_OK; > +=09=09} > + > +=09=09break; > +=09} > +=09case ACPI_IORT_NODE_PCI_ROOT_COMPLEX: { > +=09=09struct acpi_iort_root_complex *pci_rc; > +=09=09struct pci_bus *bus; > + > +=09=09bus =3D to_pci_bus(dev); > +=09=09pci_rc =3D (struct acpi_iort_root_complex *)node->node_data; > + > +=09=09/* > +=09=09 * It is assumed that PCI segment numbers maps one-to-one > +=09=09 * with root complexes. Each segment number can represent only > +=09=09 * one root complex. > +=09=09 */ > +=09=09if (pci_rc->pci_segment_number =3D=3D pci_domain_nr(bus)) > +=09=09=09return AE_OK; > + > +=09=09break; > +=09} > +=09} > + > +=09return AE_NOT_FOUND; > +} > + > +static int > +iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in, u32 *= rid_out) > +{ > +=09/* Single mapping does not care for input id */ > +=09if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) { > +=09=09if (type =3D=3D ACPI_IORT_NODE_NAMED_COMPONENT || > +=09=09 type =3D=3D ACPI_IORT_NODE_PCI_ROOT_COMPLEX) { > +=09=09=09*rid_out =3D map->output_base; > +=09=09=09return 0; > +=09=09} > + > +=09=09pr_warn(FW_BUG "[map %p] SINGLE MAPPING flag not allowed for node = type %d, skipping ID map\n", > +=09=09=09map, type); > +=09=09return -ENXIO; > +=09} > + > +=09if (rid_in < map->input_base || > +=09 (rid_in >=3D map->input_base + map->id_count)) > +=09=09return -ENXIO; > + > +=09*rid_out =3D map->output_base + (rid_in - map->input_base); > +=09return 0; > +} > + > +static struct acpi_iort_node * > +iort_node_map_rid(struct acpi_iort_node *node, u32 rid_in, > +=09=09 u32 *rid_out, u8 type) > +{ > +=09u32 rid =3D rid_in; > + > +=09/* Parse the ID mapping tree to find specified node type */ > +=09while (node) { > +=09=09struct acpi_iort_id_mapping *map; > +=09=09int i; > + > +=09=09if (node->type =3D=3D type) { > +=09=09=09if (rid_out) > +=09=09=09=09*rid_out =3D rid; > +=09=09=09return node; > +=09=09} > + > +=09=09if (!node->mapping_offset || !node->mapping_count) > +=09=09=09goto fail_map; > + > +=09=09map =3D ACPI_ADD_PTR(struct acpi_iort_id_mapping, node, > +=09=09=09=09 node->mapping_offset); > + > +=09=09/* Firmware bug! */ > +=09=09if (!map->output_reference) { > +=09=09=09pr_err(FW_BUG "[node %p type %d] ID map has NULL parent referen= ce\n", > +=09=09=09 node, node->type); > +=09=09=09goto fail_map; > +=09=09} > + > +=09=09/* Do the RID translation */ > +=09=09for (i =3D 0; i < node->mapping_count; i++, map++) { > +=09=09=09if (!iort_id_map(map, node->type, rid, &rid)) > +=09=09=09=09break; > +=09=09} > + > +=09=09if (i =3D=3D node->mapping_count) > +=09=09=09goto fail_map; > + > +=09=09node =3D ACPI_ADD_PTR(struct acpi_iort_node, iort_table, > +=09=09=09=09 map->output_reference); > +=09} > + > +fail_map: > +=09/* Map input RID to output RID unchanged on mapping failure*/ > +=09if (rid_out) > +=09=09*rid_out =3D rid_in; > + > +=09return NULL; > +} > + > +static struct acpi_iort_node * > +iort_find_dev_node(struct device *dev) > +{ > +=09struct pci_bus *pbus; > + > +=09if (!dev_is_pci(dev)) > +=09=09return iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT, > +=09=09=09=09 iort_match_node_callback, dev); > + > +=09/* Find a PCI root bus */ > +=09pbus =3D to_pci_dev(dev)->bus; > +=09while (!pci_is_root_bus(pbus)) > +=09=09pbus =3D pbus->parent; > + > +=09return iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX, > +=09=09=09 iort_match_node_callback, &pbus->dev); > +} > + > +void __init iort_table_detect(void) > +{ > +=09acpi_status status; > + > +=09status =3D acpi_get_table(ACPI_SIG_IORT, 0, &iort_table); > +=09if (ACPI_FAILURE(status) && status !=3D AE_NOT_FOUND) { > +=09=09const char *msg =3D acpi_format_exception(status); > +=09=09pr_err("Failed to get table, %s\n", msg); > +=09} > +} > diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c > index 85b7d07..55a84da 100644 > --- a/drivers/acpi/bus.c > +++ b/drivers/acpi/bus.c > @@ -36,6 +36,7 @@ > #ifdef CONFIG_X86 > #include > #endif > +#include > #include > #include > #include > @@ -1186,6 +1187,7 @@ static int __init acpi_init(void) > =09} > =20 > =09pci_mmcfg_late_init(); > +=09iort_table_detect(); > =09acpi_scan_init(); > =09acpi_ec_init(); > =09acpi_debugfs_init(); > diff --git a/include/linux/iort.h b/include/linux/iort.h > new file mode 100644 > index 0000000..cde6809 > --- /dev/null > +++ b/include/linux/iort.h > @@ -0,0 +1,30 @@ > +/* > + * Copyright (C) 2016, Semihalf > + *=09Author: 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 WITHOU= T > + * 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 alo= ng 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 > + > +#ifdef CONFIG_IORT_TABLE > +void iort_table_detect(void); > +#else > +static inline void iort_table_detect(void) { } > +#endif > + > +#endif /* __IORT_H__ */ > --=20 > 1.9.1 >=20 > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >=20