On Sun, Nov 12, 2023 at 09:44:18AM -0800, Moritz Fischer wrote:
> On Fri, Nov 03, 2023 at 01:44:55PM -0300, Jason Gunthorpe wrote:
> > This call chain is using dev->iommu->fwspec to pass around the fwspec
> > between the three parts (acpi_iommu_configure(), acpi_iommu_fwspec_init(),
> > iommu_probe_device()).
> >
> > However there is no locking around the accesses to dev->iommu, so this is
> > all racy.
> >
> > Allocate a clean, local, fwspec at the start of acpu_iommu_configure(),
> Nit: s/acpu_iommu_configure/acpi_iommu_configure_id() ?
Yep
Thanks
Jason
> > pass it through all functions on the stack to fill it with data, and
> > finally pass it into iommu_probe_device_fwspec() which will load it into
> > dev->iommu under a lock.
> >
> > Signed-off-by: Jason Gunthorpe
>
> Reviewed-by: Moritz Fischer
> > ---
> > drivers/acpi/arm64/iort.c | 39 -
> > drivers/acpi/scan.c | 89 ++-
> > drivers/acpi/viot.c | 44 ++-
> > drivers/iommu/iommu.c | 5 +--
> > include/acpi/acpi_bus.h | 8 ++--
> > include/linux/acpi_iort.h | 3 +-
> > include/linux/acpi_viot.h | 5 ++-
> > include/linux/iommu.h | 2 +
> > 8 files changed, 97 insertions(+), 98 deletions(-)
> >
> > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> > index 6496ff5a6ba20d..accd01dcfe93f5 100644
> > --- a/drivers/acpi/arm64/iort.c
> > +++ b/drivers/acpi/arm64/iort.c
> > @@ -1218,10 +1218,9 @@ static bool iort_pci_rc_supports_ats(struct
> > acpi_iort_node *node)
> > return pci_rc->ats_attribute & ACPI_IORT_ATS_SUPPORTED;
> > }
> >
> > -static int iort_iommu_xlate(struct device *dev, struct acpi_iort_node
> > *node,
> > - u32 streamid)
> > +static int iort_iommu_xlate(struct iommu_fwspec *fwspec, struct device
> > *dev,
> > + struct acpi_iort_node *node, u32 streamid)
> > {
> > - const struct iommu_ops *ops;
> > struct fwnode_handle *iort_fwnode;
> >
> > if (!node)
> > @@ -1239,17 +1238,14 @@ static int iort_iommu_xlate(struct device *dev,
> > struct acpi_iort_node *node,
> > * in the kernel or not, defer the IOMMU configuration
> > * or just abort it.
> > */
> > - ops = iommu_ops_from_fwnode(iort_fwnode);
> > - if (!ops)
> > - return iort_iommu_driver_enabled(node->type) ?
> > - -EPROBE_DEFER : -ENODEV;
> > -
> > - return acpi_iommu_fwspec_init(dev, streamid, iort_fwnode, ops);
> > + return acpi_iommu_fwspec_init(fwspec, dev, streamid, iort_fwnode,
> > + iort_iommu_driver_enabled(node->type));
> > }
> >
> > struct iort_pci_alias_info {
> > struct device *dev;
> > struct acpi_iort_node *node;
> > + struct iommu_fwspec *fwspec;
> > };
> >
> > static int iort_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data)
> > @@ -1260,7 +1256,7 @@ static int iort_pci_iommu_init(struct pci_dev *pdev,
> > u16 alias, void *data)
> >
> > parent = iort_node_map_id(info->node, alias, &streamid,
> > IORT_IOMMU_TYPE);
> > - return iort_iommu_xlate(info->dev, parent, streamid);
> > + return iort_iommu_xlate(info->fwspec, info->dev, parent, streamid);
> > }
> >
> > static void iort_named_component_init(struct device *dev,
> > @@ -1280,7 +1276,8 @@ static void iort_named_component_init(struct device
> > *dev,
> > dev_warn(dev, "Could not add device properties\n");
> > }
> >
> > -static int iort_nc_iommu_map(struct device *dev, struct acpi_iort_node
> > *node)
> > +static int iort_nc_iommu_map(struct iommu_fwspec *fwspec, struct device
> > *dev,
> > +struct acpi_iort_node *node)
> > {
> > struct acpi_iort_node *parent;
> > int err = -ENODEV, i = 0;
> > @@ -1293,13 +1290,13 @@ static int iort_nc_iommu_map(struct device *dev,
> > struct acpi_iort_node *node)
> >i++);
> >
> > if (parent)
> > - err = iort_iommu_xlate(dev, parent, streamid);
> > + err = iort_iommu_xlate(fwspec, dev, parent, streamid);
> > } while (parent && !err);
> >
> > return err;
> > }
> >
> > -static int iort_nc_iommu_map_id(struct device *dev,
> > +static int iort_nc_iommu_map_id(struct iommu_fwspec *fwspec, struct device
> > *dev,
> > struct acpi_iort_node *node,
> > const u32 *in_id)
> > {
> > @@ -1308,7 +1305,7 @@ static int iort_nc_iommu_map_id(struct device *dev,
> >
> > parent = iort_node_map_id(node, *in_id, &streamid, IORT_IOMMU_TYPE);
> > if (parent)
> > - return iort_iommu_xlate(dev, parent, streamid);
> > + return iort_iommu_xlate(fwspec, dev, parent, streamid);
> >
> > return -ENODEV;
> > }
> > @@ -1322,15 +1319,16 @@ static int iort_nc_iommu_map_id(struct device *dev,
> > *
> > * Returns: 0 on success, <0
