iommu/ipmmu-vmsa: Restrict IOMMU Domain Geometry to 32-bit address space

geertu · joergroedel · commit 3b6bb5b705a4 · 2017-02-06T13:09:43.000+01:00
Currently, the IPMMU/VMSA driver supports 32-bit I/O Virtual Addresses
only, and thus sets io_pgtable_cfg.ias = 32.  However, it doesn't force
a 32-bit IOVA space through the IOMMU Domain Geometry.

Hence if a device (e.g. SYS-DMAC) rightfully configures a 40-bit DMA
mask, it will still be handed out a 40-bit IOVA, outside the 32-bit IOVA
space, leading to out-of-bounds accesses of the PGD when mapping the
IOVA.

Force a 32-bit IOMMU Domain Geometry to fix this.

Signed-off-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Reviewed-by: Laurent Pinchart &lt;laurent.pinchart@ideasonboard.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
@@ -313,6 +313,8 @@ static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
 	domain->cfg.ias = 32;
 	domain->cfg.oas = 40;
 	domain->cfg.tlb = &ipmmu_gather_ops;
+	domain->io_domain.geometry.aperture_end = DMA_BIT_MASK(32);
+	domain->io_domain.geometry.force_aperture = true;
 	/*
 	 * TODO: Add support for coherent walk through CCI with DVM and remove
 	 * cache handling. For now, delegate it to the io-pgtable code.
