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| author |  Eric Auger <eric.auger@redhat.com>
| 2022-06-30 11:40:59 +0200 |
|---|---|---|
| committer |  Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| 2022-07-05 20:25:39 +0200 |
| commit | 3dcb861dbc6ab101838a1548b1efddd00ca3c3ec (patch) | |
| tree | 206893bed229a01f88b40ae49984ec31688c1b2d /drivers/acpi | |
| parent | Linux 5.19-rc5 (diff) | |
| download | linux-3dcb861dbc6ab101838a1548b1efddd00ca3c3ec.tar.gz linux-3dcb861dbc6ab101838a1548b1efddd00ca3c3ec.tar.bz2 linux-3dcb861dbc6ab101838a1548b1efddd00ca3c3ec.zip | |
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>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/bus.c | 1 | ||||
| -rw-r--r-- | drivers/acpi/viot.c | 26 |
2 files changed, 21 insertions, 6 deletions
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index 86fa61a21826..906ad8153fd9 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -1400,6 +1400,7 @@ static int __init acpi_init(void) pci_mmcfg_late_init(); acpi_iort_init(); + acpi_viot_early_init(); acpi_hest_init(); acpi_ghes_init(); acpi_scan_init(); diff --git a/drivers/acpi/viot.c b/drivers/acpi/viot.c index d2256326c73a..647f11cf165d 100644 --- a/drivers/acpi/viot.c +++ b/drivers/acpi/viot.c @@ -249,6 +249,26 @@ err_free: } /** + * acpi_viot_early_init - Test the presence of VIOT and enable ACS + * + * If the VIOT does exist, ACS must be enabled. This cannot be + * done in acpi_viot_init() which is called after the bus scan + */ +void __init acpi_viot_early_init(void) +{ +#ifdef CONFIG_PCI + acpi_status status; + struct acpi_table_header *hdr; + + status = acpi_get_table(ACPI_SIG_VIOT, 0, &hdr); + if (ACPI_FAILURE(status)) + return; + pci_request_acs(); + acpi_put_table(hdr); +#endif +} + +/** * acpi_viot_init - Parse the VIOT table * * Parse the VIOT table, prepare the list of endpoints to be used during DMA @@ -319,12 +339,6 @@ static int viot_pci_dev_iommu_init(struct pci_dev *pdev, u16 dev_id, void *data) epid = ((domain_nr - ep->segment_start) << 16) + dev_id - ep->bdf_start + ep->endpoint_id; - /* - * If we found a PCI range managed by the viommu, we're - * the one that has to request ACS. - */ - pci_request_acs(); - return viot_dev_iommu_init(&pdev->dev, ep->viommu, epid); } |