[PATCH v3 05/12] iommu/arm-smmu-v3: Enable HTTU for stage1 with io-pgtable mapping

From: Keqian Zhu
Date: Tue Apr 13 2021 - 04:55:45 EST


From: Kunkun Jiang <jiangkunkun@xxxxxxxxxx>

As nested mode is not upstreamed now, we just aim to support dirty
log tracking for stage1 with io-pgtable mapping (means not support
SVA mapping). If HTTU is supported, we enable HA/HD bits in the SMMU
CD, 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@xxxxxxxxxx>
Signed-off-by: Kunkun Jiang <jiangkunkun@xxxxxxxxxx>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 3 +++
drivers/iommu/io-pgtable-arm.c | 7 ++++++-
include/linux/io-pgtable.h | 3 +++
3 files changed, 12 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 b6d965504f44..369c0ea7a104 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1921,6 +1921,7 @@ static int arm_smmu_domain_finalise_s1(struct arm_smmu_domain *smmu_domain,
FIELD_PREP(CTXDESC_CD_0_TCR_ORGN0, tcr->orgn) |
FIELD_PREP(CTXDESC_CD_0_TCR_SH0, tcr->sh) |
FIELD_PREP(CTXDESC_CD_0_TCR_IPS, tcr->ips) |
+ CTXDESC_CD_0_TCR_HA | CTXDESC_CD_0_TCR_HD |
CTXDESC_CD_0_TCR_EPD1 | CTXDESC_CD_0_AA64;
cfg->cd.mair = pgtbl_cfg->arm_lpae_s1_cfg.mair;

@@ -2026,6 +2027,8 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain,

if (smmu_domain->non_strict)
pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT;
+ if (smmu->features & ARM_SMMU_FEAT_HD)
+ pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_ARM_HD;

pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain);
if (!pgtbl_ops)
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 87def58e79b5..94d790b8ed27 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->quirks & IO_PGTABLE_QUIRK_ARM_HD)
+ pte |= ARM_LPAE_PTE_DBM;
+
if (!(prot & IOMMU_PRIV))
pte |= ARM_LPAE_PTE_AP_UNPRIV;
} else {
diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
index a4c9ca2c31f1..64cee6831c97 100644
--- a/include/linux/io-pgtable.h
+++ b/include/linux/io-pgtable.h
@@ -82,6 +82,8 @@ struct io_pgtable_cfg {
*
* IO_PGTABLE_QUIRK_ARM_OUTER_WBWA: Override the outer-cacheability
* attributes set in the TCR for a non-coherent page-table walker.
+ *
+ * IO_PGTABLE_QUIRK_ARM_HD: Support hardware management of dirty status.
*/
#define IO_PGTABLE_QUIRK_ARM_NS BIT(0)
#define IO_PGTABLE_QUIRK_NO_PERMS BIT(1)
@@ -89,6 +91,7 @@ struct io_pgtable_cfg {
#define IO_PGTABLE_QUIRK_NON_STRICT BIT(4)
#define IO_PGTABLE_QUIRK_ARM_TTBR1 BIT(5)
#define IO_PGTABLE_QUIRK_ARM_OUTER_WBWA BIT(6)
+ #define IO_PGTABLE_QUIRK_ARM_HD BIT(7)
unsigned long quirks;
unsigned long pgsize_bitmap;
unsigned int ias;
--
2.19.1