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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 acpi_iort_init() 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@semihalf.com> Acked-by: Rafael J. Wysocki <rjw@rjwysocki.net> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
31 lines
959 B
C
31 lines
959 B
C
/*
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* Copyright (C) 2016, Semihalf
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* Author: Tomasz Nowicki <tn@semihalf.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
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* Place - Suite 330, Boston, MA 02111-1307 USA.
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*/
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#ifndef __ACPI_IORT_H__
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#define __ACPI_IORT_H__
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#include <linux/acpi.h>
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#ifdef CONFIG_ACPI_IORT
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void acpi_iort_init(void);
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#else
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static inline void acpi_iort_init(void) { }
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#endif
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#endif /* __ACPI_IORT_H__ */
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