iommu/ipmmu-vmsa: Allow two bit SL0

Introduce support for two bit SL0 bitfield in IMTTBCR
by using a separate feature flag.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

1 files changed, 13 insertions, 1 deletions

diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
index 49f2c697b108..65ad6910cb70 100644
--- a/drivers/iommu/ipmmu-vmsa.c
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -45,6 +45,7 @@ struct ipmmu_features {
         bool has_cache_leaf_nodes;
         unsigned int number_of_contexts;
         bool setup_imbuscr;
+        bool twobit_imttbcr_sl0;
 };
 
 struct ipmmu_vmsa_device {
@@ -144,6 +145,10 @@ static struct ipmmu_vmsa_device *to_ipmmu(struct device *dev)
 #define IMTTBCR_TSZ0_MASK               (7 << 0)
 #define IMTTBCR_TSZ0_SHIFT              O
 
+#define IMTTBCR_SL0_TWOBIT_LVL_3        (0 << 6)
+#define IMTTBCR_SL0_TWOBIT_LVL_2        (1 << 6)
+#define IMTTBCR_SL0_TWOBIT_LVL_1        (2 << 6)
+
 #define IMBUSCR                         0x000c
 #define IMBUSCR_DVM                     (1 << 2)
 #define IMBUSCR_BUSSEL_SYS              (0 << 0)
@@ -396,6 +401,7 @@ static void ipmmu_domain_free_context(struct ipmmu_vmsa_device *mmu,
 static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
 {
         u64 ttbr;
+        u32 tmp;
         int ret;
 
         /*
@@ -449,9 +455,14 @@ static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
          * We use long descriptors with inner-shareable WBWA tables and allocate
          * the whole 32-bit VA space to TTBR0.
          */
+        if (domain->mmu->features->twobit_imttbcr_sl0)
+                tmp = IMTTBCR_SL0_TWOBIT_LVL_1;
+        else
+                tmp = IMTTBCR_SL0_LVL_1;
+
         ipmmu_ctx_write_root(domain, IMTTBCR, IMTTBCR_EAE |
                              IMTTBCR_SH0_INNER_SHAREABLE | IMTTBCR_ORGN0_WB_WA |
-                             IMTTBCR_IRGN0_WB_WA | IMTTBCR_SL0_LVL_1);
+                             IMTTBCR_IRGN0_WB_WA | tmp);
 
         /* MAIR0 */
         ipmmu_ctx_write_root(domain, IMMAIR0,
@@ -889,6 +900,7 @@ static const struct ipmmu_features ipmmu_features_default = {
         .has_cache_leaf_nodes = false,
         .number_of_contexts = 1, /* software only tested with one context */
         .setup_imbuscr = true,
+        .twobit_imttbcr_sl0 = false,
 };
 
 static const struct of_device_id ipmmu_of_ids[] = {