From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
[ Upstream commit 2ae86955703e9e6a119af4bbe27f6b6dd7a43131 ]
The TTSEL bit of IMUCTRn register of R-Car Gen3 needs to be set
unused MMU context number even if uTLBs are disabled
(The MMUEN bit of IMUCTRn register = 0).
Since initial values of IMUCTRn.TTSEL on all IPMMU-domains are 0,
this patch adds a new feature "reserved_context" to reserve IPMMU
context number 0 as the unused MMU context.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
drivers/iommu/ipmmu-vmsa.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
index 40ae6e87cb88..559ecdf84729 100644
--- a/drivers/iommu/ipmmu-vmsa.c
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -47,6 +47,7 @@ struct ipmmu_features {
unsigned int number_of_contexts;
bool setup_imbuscr;
bool twobit_imttbcr_sl0;
+ bool reserved_context;
};
struct ipmmu_vmsa_device {
@@ -917,6 +918,7 @@ static const struct ipmmu_features ipmmu_features_default = {
.number_of_contexts = 1, /* software only tested with one context */
.setup_imbuscr = true,
.twobit_imttbcr_sl0 = false,
+ .reserved_context = false,
};
static const struct ipmmu_features ipmmu_features_r8a7795 = {
@@ -925,6 +927,7 @@ static const struct ipmmu_features ipmmu_features_r8a7795 = {
.number_of_contexts = 8,
.setup_imbuscr = false,
.twobit_imttbcr_sl0 = true,
+ .reserved_context = true,
};
static const struct of_device_id ipmmu_of_ids[] = {
@@ -1018,6 +1021,11 @@ static int ipmmu_probe(struct platform_device *pdev)
}
ipmmu_device_reset(mmu);
+
+ if (mmu->features->reserved_context) {
+ dev_info(&pdev->dev, "IPMMU context 0 is reserved\n");
+ set_bit(0, mmu->ctx);
+ }
}
/*
--
2.17.1
