iommu/ipmmu-vmsa: Make IMBUSCTR setup optional
Introduce a feature to allow opt-out of setting up
IMBUSCR. The default case is unchanged.
Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
index 7587017..49f2c69 100644
--- a/drivers/iommu/ipmmu-vmsa.c
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -44,6 +44,7 @@ struct ipmmu_features {
bool use_ns_alias_offset;
bool has_cache_leaf_nodes;
unsigned int number_of_contexts;
+ bool setup_imbuscr;
};
struct ipmmu_vmsa_device {
@@ -457,9 +458,10 @@ static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
domain->cfg.arm_lpae_s1_cfg.mair[0]);
/* IMBUSCR */
- ipmmu_ctx_write_root(domain, IMBUSCR,
- ipmmu_ctx_read_root(domain, IMBUSCR) &
- ~(IMBUSCR_DVM | IMBUSCR_BUSSEL_MASK));
+ if (domain->mmu->features->setup_imbuscr)
+ ipmmu_ctx_write_root(domain, IMBUSCR,
+ ipmmu_ctx_read_root(domain, IMBUSCR) &
+ ~(IMBUSCR_DVM | IMBUSCR_BUSSEL_MASK));
/*
* IMSTR
@@ -886,6 +888,7 @@ static const struct ipmmu_features ipmmu_features_default = {
.use_ns_alias_offset = true,
.has_cache_leaf_nodes = false,
.number_of_contexts = 1, /* software only tested with one context */
+ .setup_imbuscr = true,
};
static const struct of_device_id ipmmu_of_ids[] = {