diff options
| author | Jean-Philippe Brucker <jean-philippe@linaro.org> | 2021-06-18 18:20:58 +0300 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2021-06-25 16:02:43 +0300 |
| commit | 3cf485540e7b8550936ce3602edf2f58e4007304 (patch) | |
| tree | 0180e6f4e59823ea625fdbf064e6384dd67c1dba /drivers/acpi/scan.c | |
| parent | 11a8c5e3a94b12848f24d9c63b5c175ce0b80729 (diff) | |
| download | linux-3cf485540e7b8550936ce3602edf2f58e4007304.tar.xz | |
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>
Diffstat (limited to 'drivers/acpi/scan.c')
| -rw-r--r-- | drivers/acpi/scan.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 2a2e690040e9..3e2bb04ab528 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -9,6 +9,7 @@ #include <linux/kernel.h> #include <linux/acpi.h> #include <linux/acpi_iort.h> +#include <linux/acpi_viot.h> #include <linux/iommu.h> #include <linux/signal.h> #include <linux/kthread.h> @@ -1556,6 +1557,8 @@ static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev, return ops; err = iort_iommu_configure_id(dev, id_in); + if (err && err != -EPROBE_DEFER) + err = viot_iommu_configure(dev); /* * If we have reason to believe the IOMMU driver missed the initial |