iommu/io-pgtable-arm: Rationalise TCR handling

Although it's conceptually nice for the io_pgtable_cfg to provide a
standard VMSA TCR value, the reality is that no VMSA-compliant IOMMU
looks exactly like an Arm CPU, and they all have various other TCR
controls which io-pgtable can't be expected to understand. Thus since
there is an expectation that drivers will have to add to the given TCR
value anyway, let's strip it down to just the essentials that are
directly relevant to io-pgtable's inner workings - namely the various
sizes and the walk attributes.

Tested-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[will: Add missing include of bitfield.h]
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 8 insertions, 1 deletions

diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
index 53bca5343f52..6ae104cedfd7 100644
--- a/include/linux/io-pgtable.h
+++ b/include/linux/io-pgtable.h
@@ -101,7 +101,14 @@ struct io_pgtable_cfg {
 	union {
 		struct {
 			u64	ttbr;
-			u64	tcr;
+			struct {
+				u32	ips:3;
+				u32	tg:2;
+				u32	sh:2;
+				u32	orgn:2;
+				u32	irgn:2;
+				u32	tsz:6;
+			}	tcr;
 			u64	mair;
 		} arm_lpae_s1_cfg;