[RFC PATCH 02/11] iommu/arm-smmu-v3: Enable HTTU for SMMU stage1 mapping

Keqian Zhu
2021-01-28T15:20:54Z

From: jiangkunkun <jiangkunkun@huawei.com>

If HTTU is supported, we enable HA/HD bits in the SMMU CD (stage 1
mapping), and set DBM bit for writable TTD.

The dirty state information is encoded using the access permission
bits AP[2] (stage 1) or S2AP[1] (stage 2) in conjunction with the
DBM (Dirty Bit Modifier) bit, where DBM means writable and AP[2]/
S2AP[1] means dirty.

Co-developed-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Kunkun Jiang <jiangkunkun@huawei.com>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 5 +++++
drivers/iommu/io-pgtable-arm.c | 7 ++++++-
2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 0f0fe71cc10d..8cc9d7536b08 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1036,6 +1036,11 @@ int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain, int ssid,
FIELD_PREP(CTXDESC_CD_0_ASID, cd->asid) |
CTXDESC_CD_0_V;

+ if (smmu->features & ARM_SMMU_FEAT_HTTU_HA)
+ val |= CTXDESC_CD_0_HA;
+ if (smmu->features & ARM_SMMU_FEAT_HTTU_HD)
+ val |= CTXDESC_CD_0_HD;
+
/* STALL_MODEL==0b10 && CD.S==0 is ILLEGAL */
if (smmu->features & ARM_SMMU_FEAT_STALL_FORCE)
val |= CTXDESC_CD_0_S;
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 87def58e79b5..e299a44808ae 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -72,6 +72,7 @@

#define ARM_LPAE_PTE_NSTABLE (((arm_lpae_iopte)1) << 63)
#define ARM_LPAE_PTE_XN (((arm_lpae_iopte)3) << 53)
+#define ARM_LPAE_PTE_DBM (((arm_lpae_iopte)1) << 51)
#define ARM_LPAE_PTE_AF (((arm_lpae_iopte)1) << 10)
#define ARM_LPAE_PTE_SH_NS (((arm_lpae_iopte)0) << 8)
#define ARM_LPAE_PTE_SH_OS (((arm_lpae_iopte)2) << 8)
@@ -81,7 +82,7 @@

#define ARM_LPAE_PTE_ATTR_LO_MASK (((arm_lpae_iopte)0x3ff) << 2)
/* Ignore the contiguous bit for block splitting */
-#define ARM_LPAE_PTE_ATTR_HI_MASK (((arm_lpae_iopte)6) << 52)
+#define ARM_LPAE_PTE_ATTR_HI_MASK (((arm_lpae_iopte)13) << 51)
#define ARM_LPAE_PTE_ATTR_MASK (ARM_LPAE_PTE_ATTR_LO_MASK | \
ARM_LPAE_PTE_ATTR_HI_MASK)
/* Software bit for solving coherency races */
@@ -379,6 +380,7 @@ static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
static arm_lpae_iopte arm_lpae_prot_to_pte(struct arm_lpae_io_pgtable *data,
int prot)
{
+ struct io_pgtable_cfg *cfg = &data->iop.cfg;
arm_lpae_iopte pte;

if (data->iop.fmt == ARM_64_LPAE_S1 ||
@@ -386,6 +388,9 @@ static arm_lpae_iopte arm_lpae_prot_to_pte(struct arm_lpae_io_pgtable *data,
pte = ARM_LPAE_PTE_nG;
if (!(prot & IOMMU_WRITE) && (prot & IOMMU_READ))
pte |= ARM_LPAE_PTE_AP_RDONLY;
+ else if (cfg->httu_hd)
+ pte |= ARM_LPAE_PTE_DBM;
+
if (!(prot & IOMMU_PRIV))
pte |= ARM_LPAE_PTE_AP_UNPRIV;
} else {
--
2.19.1