UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity
OpenCloudOS-Kernel/include/linux/acpi_viot.h

22 lines
478 B
C
Raw Normal View History

ACPI: Add driver for the VIOT table The ACPI Virtual I/O Translation Table describes topology of para-virtual platforms, similarly to vendor tables DMAR, IVRS and IORT. For now it describes the relation between virtio-iommu and the endpoints it manages. Three steps are needed to configure DMA of endpoints: (1) acpi_viot_init(): parse the VIOT table, find or create the fwnode associated to each vIOMMU device. This needs to happen after acpi_scan_init(), because it relies on the struct device and their fwnode to be available. (2) When probing the vIOMMU device, the driver registers its IOMMU ops within the IOMMU subsystem. This step doesn't require any intervention from the VIOT driver. (3) viot_iommu_configure(): before binding the endpoint to a driver, find the associated IOMMU ops. Register them, along with the endpoint ID, into the device's iommu_fwspec. If step (3) happens before step (2), it is deferred until the IOMMU is initialized, then retried. Tested-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Acked-by: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20210618152059.1194210-4-jean-philippe@linaro.org Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-06-18 23:20:58 +08:00
/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef __ACPI_VIOT_H__
#define __ACPI_VIOT_H__
#include <linux/acpi.h>
#ifdef CONFIG_ACPI_VIOT
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: 3cf485540e7b ("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>
2022-06-30 17:40:59 +08:00
void __init acpi_viot_early_init(void);
ACPI: Add driver for the VIOT table The ACPI Virtual I/O Translation Table describes topology of para-virtual platforms, similarly to vendor tables DMAR, IVRS and IORT. For now it describes the relation between virtio-iommu and the endpoints it manages. Three steps are needed to configure DMA of endpoints: (1) acpi_viot_init(): parse the VIOT table, find or create the fwnode associated to each vIOMMU device. This needs to happen after acpi_scan_init(), because it relies on the struct device and their fwnode to be available. (2) When probing the vIOMMU device, the driver registers its IOMMU ops within the IOMMU subsystem. This step doesn't require any intervention from the VIOT driver. (3) viot_iommu_configure(): before binding the endpoint to a driver, find the associated IOMMU ops. Register them, along with the endpoint ID, into the device's iommu_fwspec. If step (3) happens before step (2), it is deferred until the IOMMU is initialized, then retried. Tested-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Acked-by: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20210618152059.1194210-4-jean-philippe@linaro.org Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-06-18 23:20:58 +08:00
void __init acpi_viot_init(void);
int viot_iommu_configure(struct device *dev);
#else
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: 3cf485540e7b ("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>
2022-06-30 17:40:59 +08:00
static inline void acpi_viot_early_init(void) {}
ACPI: Add driver for the VIOT table The ACPI Virtual I/O Translation Table describes topology of para-virtual platforms, similarly to vendor tables DMAR, IVRS and IORT. For now it describes the relation between virtio-iommu and the endpoints it manages. Three steps are needed to configure DMA of endpoints: (1) acpi_viot_init(): parse the VIOT table, find or create the fwnode associated to each vIOMMU device. This needs to happen after acpi_scan_init(), because it relies on the struct device and their fwnode to be available. (2) When probing the vIOMMU device, the driver registers its IOMMU ops within the IOMMU subsystem. This step doesn't require any intervention from the VIOT driver. (3) viot_iommu_configure(): before binding the endpoint to a driver, find the associated IOMMU ops. Register them, along with the endpoint ID, into the device's iommu_fwspec. If step (3) happens before step (2), it is deferred until the IOMMU is initialized, then retried. Tested-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Acked-by: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20210618152059.1194210-4-jean-philippe@linaro.org Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-06-18 23:20:58 +08:00
static inline void acpi_viot_init(void) {}
static inline int viot_iommu_configure(struct device *dev)
{
return -ENODEV;
}
#endif
#endif /* __ACPI_VIOT_H__ */