linux-stable/include/linux/acpi_viot.h
Eric Auger 3dcb861dbc ACPI: VIOT: Fix ACS setup
Currently acpi_viot_init() gets called after the pci
device has been scanned and pci_enable_acs() has been called.
So pci_request_acs() fails to be taken into account leading
to wrong single iommu group topologies when dealing with
multi-function root ports for instance.

We cannot simply move the acpi_viot_init() earlier, similarly
as the IORT init because the VIOT parsing relies on the pci
scan. However we can detect VIOT is present earlier and in
such a case, request ACS. Introduce a new acpi_viot_early_init()
routine that allows to call pci_request_acs() before the scan.

While at it, guard the call to pci_request_acs() with #ifdef
CONFIG_PCI.

Fixes: 3cf485540e ("ACPI: Add driver for the VIOT table")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reported-by: Jin Liu <jinl@redhat.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Tested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-07-05 20:25:39 +02:00

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C

/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef __ACPI_VIOT_H__
#define __ACPI_VIOT_H__
#include <linux/acpi.h>
#ifdef CONFIG_ACPI_VIOT
void __init acpi_viot_early_init(void);
void __init acpi_viot_init(void);
int viot_iommu_configure(struct device *dev);
#else
static inline void acpi_viot_early_init(void) {}
static inline void acpi_viot_init(void) {}
static inline int viot_iommu_configure(struct device *dev)
{
return -ENODEV;
}
#endif
#endif /* __ACPI_VIOT_H__ */