From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dennis Chen Subject: Re: [PATCH V10 1/8] ACPI: I/O Remapping Table (IORT) initial support Date: Fri, 9 Sep 2016 11:09:40 +0800 Message-ID: <20160909030938.GA8544@arm.com> References: <1473152938-17388-1-git-send-email-tn@semihalf.com> <1473152938-17388-2-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: <1473152938-17388-2-git-send-email-tn@semihalf.com> Content-Disposition: inline Sender: linux-pci-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 Tue, Sep 06, 2016 at 11:08:51AM +0200, Tomasz Nowicki wrote: [...] > +static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 ri= d_in, > +=09=09 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 *n= ode, > +=09=09=09=09=09=09u32 rid_in, u32 *rid_out, > +=09=09=09=09=09=09u8 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; If node->mapping_count is zero, then node->mapping_offset must be zero. A f= irmware bug otherwise? > + > +=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} > Just curious about if there is kind of possibility that we can get some red= uplicated DeviceIDs with a deliberate ID mapping design in FW for the SMMU/RC node. For instanc= e, for a system with 2 PCIe RCs both behind an individual SMMU device, how to make sure the Stream= ID mapped is unique=20 across the entire system, the same for DeviceID mapped.=20 Anyway, this is my personal confusion, maybe it's not a problem at all for = current design ;-) Thanks, Dennis > + > +=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 acpi_iort_init(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..e56e643 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(); > +=09acpi_iort_init(); > =09acpi_scan_init(); > =09acpi_ec_init(); > =09acpi_debugfs_init(); > diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h > new file mode 100644 > index 0000000..fcacaf7 > --- /dev/null > +++ b/include/linux/acpi_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 __ACPI_IORT_H__ > +#define __ACPI_IORT_H__ > + > +#include > + > +#ifdef CONFIG_ACPI_IORT > +void acpi_iort_init(void); > +#else > +static inline void acpi_iort_init(void) { } > +#endif > + > +#endif /* __ACPI_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