linux-next/include/linux/acpi_iort.h
Lorenzo Pieralisi 34ceea275f ACPI/IORT: Introduce linker section for IORT entries probing
Since commit e647b532275b ("ACPI: Add early device probing
infrastructure") the kernel has gained the infrastructure that allows
adding linker script section entries to execute ACPI driver callbacks
(ie probe routines) for all subsystems that register a table entry
in the respective kernel section (eg clocksource, irqchip).

Since ARM IOMMU devices data is described through IORT tables when
booting with ACPI, the ARM IOMMU drivers must be made able to hook ACPI
callback routines that are called to probe IORT entries and initialize
the respective IOMMU devices.

To avoid adding driver specific hooks into IORT table initialization
code (breaking therefore code modularity - ie ACPI IORT code must be made
aware of ARM SMMU drivers ACPI init callbacks), this patch adds code
that allows ARM SMMU drivers to take advantage of the ACPI early probing
infrastructure, so that they can add linker script section entries
containing drivers callback to be executed on IORT tables detection.

Since IORT nodes are differentiated by a type, the callback routines
can easily parse the IORT table entries, check the IORT nodes and
carry out some actions whenever the IORT node type associated with
the driver specific callback is matched.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Reviewed-by: Tomasz Nowicki <tn@semihalf.com>
Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Tested-by: Tomasz Nowicki <tn@semihalf.com>
Cc: Tomasz Nowicki <tn@semihalf.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-11-29 15:57:42 +00:00

46 lines
1.6 KiB
C

/*
* Copyright (C) 2016, Semihalf
* Author: Tomasz Nowicki <tn@semihalf.com>
*
* 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 __ACPI_IORT_H__
#define __ACPI_IORT_H__
#include <linux/acpi.h>
#include <linux/fwnode.h>
#include <linux/irqdomain.h>
int iort_register_domain_token(int trans_id, struct fwnode_handle *fw_node);
void iort_deregister_domain_token(int trans_id);
struct fwnode_handle *iort_find_domain_token(int trans_id);
#ifdef CONFIG_ACPI_IORT
void acpi_iort_init(void);
u32 iort_msi_map_rid(struct device *dev, u32 req_id);
struct irq_domain *iort_get_device_domain(struct device *dev, u32 req_id);
#else
static inline void acpi_iort_init(void) { }
static inline u32 iort_msi_map_rid(struct device *dev, u32 req_id)
{ return req_id; }
static inline struct irq_domain *iort_get_device_domain(struct device *dev,
u32 req_id)
{ return NULL; }
#endif
#define IORT_ACPI_DECLARE(name, table_id, fn) \
ACPI_DECLARE_PROBE_ENTRY(iort, name, table_id, 0, NULL, 0, fn)
#endif /* __ACPI_IORT_H__ */