[PATCH v7 3/9] iommu/arm-smmu-v3: Move the CD generation for S1 domains into a function

Jason Gunthorpe
2024-04-16T19:29:49Z

Introduce arm_smmu_make_s1_cd() to build the CD from the paging S1 domain,
and reorganize all the places programming S1 domain CD table entries to
call it.

Split arm_smmu_update_s1_domain_cd_entry() from
arm_smmu_update_ctx_desc_devices() so that the S1 path has its own call
chain separate from the unrelated SVA path.

arm_smmu_update_s1_domain_cd_entry() only works on S1 domains
attached to RIDs and refreshes all their CDs.

Remove the forced clear of the CD during S1 domain attach,
arm_smmu_write_cd_entry() will do this automatically if necessary.

Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Michael Shavit <mshavit@google.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
.../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 25 +++++++-
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 60 +++++++++++++------
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 9 +++
3 files changed, 76 insertions(+), 18 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index 41b44baef15e80..d159f60480935e 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -53,6 +53,29 @@ static void arm_smmu_update_ctx_desc_devices(struct arm_smmu_domain *smmu_domain
spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
}

+static void
+arm_smmu_update_s1_domain_cd_entry(struct arm_smmu_domain *smmu_domain)
+{
+ struct arm_smmu_master *master;
+ struct arm_smmu_cd target_cd;
+ unsigned long flags;
+
+ spin_lock_irqsave(&smmu_domain->devices_lock, flags);
+ list_for_each_entry(master, &smmu_domain->devices, domain_head) {
+ struct arm_smmu_cd *cdptr;
+
+ /* S1 domains only support RID attachment right now */
+ cdptr = arm_smmu_get_cd_ptr(master, IOMMU_NO_PASID);
+ if (WARN_ON(!cdptr))
+ continue;
+
+ arm_smmu_make_s1_cd(&target_cd, master, smmu_domain);
+ arm_smmu_write_cd_entry(master, IOMMU_NO_PASID, cdptr,
+ &target_cd);
+ }
+ spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
+}
+
/*
* Check if the CPU ASID is available on the SMMU side. If a private context
* descriptor is using it, try to replace it.
@@ -96,7 +119,7 @@ arm_smmu_share_asid(struct mm_struct *mm, u16 asid)
* be some overlap between use of both ASIDs, until we invalidate the
* TLB.
*/
- arm_smmu_update_ctx_desc_devices(smmu_domain, IOMMU_NO_PASID, cd);
+ arm_smmu_update_s1_domain_cd_entry(smmu_domain);

/* Invalidate TLB entries previously associated with that context */
arm_smmu_tlb_inv_asid(smmu, asid);
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 3983de90c2fa01..d24fa13a52b4e0 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1204,8 +1204,8 @@ static void arm_smmu_write_cd_l1_desc(__le64 *dst,
WRITE_ONCE(*dst, cpu_to_le64(val));
}

-static struct arm_smmu_cd *arm_smmu_get_cd_ptr(struct arm_smmu_master *master,
- u32 ssid)
+struct arm_smmu_cd *arm_smmu_get_cd_ptr(struct arm_smmu_master *master,
+ u32 ssid)
{
__le64 *l1ptr;
unsigned int idx;
@@ -1268,9 +1268,9 @@ static const struct arm_smmu_entry_writer_ops arm_smmu_cd_writer_ops = {
.v_bit = cpu_to_le64(CTXDESC_CD_0_V),
};

-static void arm_smmu_write_cd_entry(struct arm_smmu_master *master, int ssid,
- struct arm_smmu_cd *cdptr,
- const struct arm_smmu_cd *target)
+void arm_smmu_write_cd_entry(struct arm_smmu_master *master, int ssid,
+ struct arm_smmu_cd *cdptr,
+ const struct arm_smmu_cd *target)
{
struct arm_smmu_cd_writer cd_writer = {
.writer = {
@@ -1283,6 +1283,32 @@ static void arm_smmu_write_cd_entry(struct arm_smmu_master *master, int ssid,
arm_smmu_write_entry(&cd_writer.writer, cdptr->data, target->data);
}

+void arm_smmu_make_s1_cd(struct arm_smmu_cd *target,
+ struct arm_smmu_master *master,
+ struct arm_smmu_domain *smmu_domain)
+{
+ struct arm_smmu_ctx_desc *cd = &smmu_domain->cd;
+
+ memset(target, 0, sizeof(*target));
+
+ target->data[0] = cpu_to_le64(
+ cd->tcr |
+#ifdef __BIG_ENDIAN
+ CTXDESC_CD_0_ENDI |
+#endif
+ CTXDESC_CD_0_V |
+ CTXDESC_CD_0_AA64 |
+ (master->stall_enabled ? CTXDESC_CD_0_S : 0) |
+ CTXDESC_CD_0_R |
+ CTXDESC_CD_0_A |
+ CTXDESC_CD_0_ASET |
+ FIELD_PREP(CTXDESC_CD_0_ASID, cd->asid)
+ );
+
+ target->data[1] = cpu_to_le64(cd->ttbr & CTXDESC_CD_1_TTB0_MASK);
+ target->data[3] = cpu_to_le64(cd->mair);
+}
+
static void arm_smmu_clean_cd_entry(struct arm_smmu_cd *target)
{
struct arm_smmu_cd used = {};
@@ -2644,29 +2670,29 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);

switch (smmu_domain->stage) {
- case ARM_SMMU_DOMAIN_S1:
+ case ARM_SMMU_DOMAIN_S1: {
+ struct arm_smmu_cd target_cd;
+ struct arm_smmu_cd *cdptr;
+
if (!master->cd_table.cdtab) {
ret = arm_smmu_alloc_cd_tables(master);
if (ret)
goto out_list_del;
- } else {
- /*
- * arm_smmu_write_ctx_desc() relies on the entry being
- * invalid to work, clear any existing entry.
- */
- ret = arm_smmu_write_ctx_desc(master, IOMMU_NO_PASID,
- NULL);
- if (ret)
- goto out_list_del;
}

- ret = arm_smmu_write_ctx_desc(master, IOMMU_NO_PASID, &smmu_domain->cd);
- if (ret)
+ cdptr = arm_smmu_get_cd_ptr(master, IOMMU_NO_PASID);
+ if (!cdptr) {
+ ret = -ENOMEM;
goto out_list_del;
+ }

+ arm_smmu_make_s1_cd(&target_cd, master, smmu_domain);
+ arm_smmu_write_cd_entry(master, IOMMU_NO_PASID, cdptr,
+ &target_cd);
arm_smmu_make_cdtable_ste(&target, master);
arm_smmu_install_ste_for_dev(master, &target);
break;
+ }
case ARM_SMMU_DOMAIN_S2:
arm_smmu_make_s2_domain_ste(&target, master, smmu_domain);
arm_smmu_install_ste_for_dev(master, &target);
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index 4b767e0eeeb682..bb08f087ba39e4 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -751,6 +751,15 @@ extern struct xarray arm_smmu_asid_xa;
extern struct mutex arm_smmu_asid_lock;
extern struct arm_smmu_ctx_desc quiet_cd;

+struct arm_smmu_cd *arm_smmu_get_cd_ptr(struct arm_smmu_master *master,
+ u32 ssid);
+void arm_smmu_make_s1_cd(struct arm_smmu_cd *target,
+ struct arm_smmu_master *master,
+ struct arm_smmu_domain *smmu_domain);
+void arm_smmu_write_cd_entry(struct arm_smmu_master *master, int ssid,
+ struct arm_smmu_cd *cdptr,
+ const struct arm_smmu_cd *target);
+
int arm_smmu_write_ctx_desc(struct arm_smmu_master *smmu_master, int ssid,
struct arm_smmu_ctx_desc *cd);
void arm_smmu_tlb_inv_asid(struct arm_smmu_device *smmu, u16 asid);
--
2.43.2