[PATCH v3 07/11] iommu/vt-d: Acquiring lock in pasid manipulation helpers

Lu Baolu
2022-06-29T07:52:24Z

The iommu->lock is used to protect the per-IOMMU pasid directory table
and pasid table. Move the spinlock acquisition/release into the helpers
to make the code self-contained.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
---
drivers/iommu/intel/iommu.c | 2 -
drivers/iommu/intel/pasid.c | 103 +++++++++++++++++++-----------------
drivers/iommu/intel/svm.c | 3 --
3 files changed, 55 insertions(+), 53 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 5681b8ef11f1..f45a769695c3 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2494,7 +2494,6 @@ static int domain_add_dev_info(struct dmar_domain *domain, struct device *dev)
}

/* Setup the PASID entry for requests without PASID: */
- spin_lock(&iommu->lock);
if (hw_pass_through && domain_type_is_si(domain))
ret = intel_pasid_setup_pass_through(iommu, domain,
dev, PASID_RID2PASID);
@@ -2504,7 +2503,6 @@ static int domain_add_dev_info(struct dmar_domain *domain, struct device *dev)
else
ret = intel_pasid_setup_second_level(iommu, domain,
dev, PASID_RID2PASID);
- spin_unlock(&iommu->lock);
if (ret) {
dev_err(dev, "Setup RID2PASID failed\n");
dmar_remove_one_dev_info(dev);
diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index 43f090381ec7..7792a1b2ebc4 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -450,17 +450,17 @@ void intel_pasid_tear_down_entry(struct intel_iommu *iommu, struct device *dev,
struct pasid_entry *pte;
u16 did, pgtt;

+ spin_lock(&iommu->lock);
pte = intel_pasid_get_entry(dev, pasid);
- if (WARN_ON(!pte))
- return;
-
- if (!pasid_pte_is_present(pte))
+ if (WARN_ON(!pte) || !pasid_pte_is_present(pte)) {
+ spin_unlock(&iommu->lock);
return;
+ }

did = pasid_get_domain_id(pte);
pgtt = pasid_pte_get_pgtt(pte);
-
intel_pasid_clear_entry(dev, pasid, fault_ignore);
+ spin_unlock(&iommu->lock);

if (!ecap_coherent(iommu->ecap))
clflush_cache_range(pte, sizeof(*pte));
@@ -496,22 +496,6 @@ static void pasid_flush_caches(struct intel_iommu *iommu,
}
}

-static inline int pasid_enable_wpe(struct pasid_entry *pte)
-{
-#ifdef CONFIG_X86
- unsigned long cr0 = read_cr0();
-
- /* CR0.WP is normally set but just to be sure */
- if (unlikely(!(cr0 & X86_CR0_WP))) {
- pr_err_ratelimited("No CPU write protect!\n");
- return -EINVAL;
- }
-#endif
- pasid_set_wpe(pte);
-
- return 0;
-};
-
/*
* Set up the scalable mode pasid table entry for first only
* translation type.
@@ -528,39 +512,52 @@ int intel_pasid_setup_first_level(struct intel_iommu *iommu,
return -EINVAL;
}

- pte = intel_pasid_get_entry(dev, pasid);
- if (WARN_ON(!pte))
+ if (flags & PASID_FLAG_SUPERVISOR_MODE) {
+#ifdef CONFIG_X86
+ unsigned long cr0 = read_cr0();
+
+ /* CR0.WP is normally set but just to be sure */
+ if (unlikely(!(cr0 & X86_CR0_WP))) {
+ pr_err("No CPU write protect!\n");
+ return -EINVAL;
+ }
+#endif
+ if (!ecap_srs(iommu->ecap)) {
+ pr_err("No supervisor request support on %s\n",
+ iommu->name);
+ return -EINVAL;
+ }
+ }
+
+ if ((flags & PASID_FLAG_FL5LP) && !cap_5lp_support(iommu->cap)) {
+ pr_err("No 5-level paging support for first-level on %s\n",
+ iommu->name);
return -EINVAL;
+ }

- /* Caller must ensure PASID entry is not in use. */
- if (pasid_pte_is_present(pte))
+ spin_lock(&iommu->lock);
+ pte = intel_pasid_get_entry(dev, pasid);
+ if (!pte) {
+ spin_unlock(&iommu->lock);
+ return -ENODEV;
+ }
+
+ if (pasid_pte_is_present(pte)) {
+ spin_unlock(&iommu->lock);
return -EBUSY;
+ }

pasid_clear_entry(pte);

/* Setup the first level page table pointer: */
pasid_set_flptr(pte, (u64)__pa(pgd));
if (flags & PASID_FLAG_SUPERVISOR_MODE) {
- if (!ecap_srs(iommu->ecap)) {
- pr_err("No supervisor request support on %s\n",
- iommu->name);
- return -EINVAL;
- }
pasid_set_sre(pte);
- if (pasid_enable_wpe(pte))
- return -EINVAL;
-
+ pasid_set_wpe(pte);
}

- if (flags & PASID_FLAG_FL5LP) {
- if (cap_5lp_support(iommu->cap)) {
- pasid_set_flpm(pte, 1);
- } else {
- pr_err("No 5-level paging support for first-level\n");
- pasid_clear_entry(pte);
- return -EINVAL;
- }
- }
+ if (flags & PASID_FLAG_FL5LP)
+ pasid_set_flpm(pte, 1);

if (flags & PASID_FLAG_PAGE_SNOOP)
pasid_set_pgsnp(pte);
@@ -572,6 +569,8 @@ int intel_pasid_setup_first_level(struct intel_iommu *iommu,
/* Setup Present and PASID Granular Transfer Type: */
pasid_set_translation_type(pte, PASID_ENTRY_PGTT_FL_ONLY);
pasid_set_present(pte);
+ spin_unlock(&iommu->lock);
+
pasid_flush_caches(iommu, pte, pasid, did);

return 0;
@@ -629,15 +628,17 @@ int intel_pasid_setup_second_level(struct intel_iommu *iommu,
pgd_val = virt_to_phys(pgd);
did = domain->iommu_did[iommu->seq_id];

+ spin_lock(&iommu->lock);
pte = intel_pasid_get_entry(dev, pasid);
if (!pte) {
- dev_err(dev, "Failed to get pasid entry of PASID %d\n", pasid);
+ spin_unlock(&iommu->lock);
return -ENODEV;
}

- /* Caller must ensure PASID entry is not in use. */
- if (pasid_pte_is_present(pte))
+ if (pasid_pte_is_present(pte)) {
+ spin_unlock(&iommu->lock);
return -EBUSY;
+ }

pasid_clear_entry(pte);
pasid_set_domain_id(pte, did);
@@ -654,6 +655,8 @@ int intel_pasid_setup_second_level(struct intel_iommu *iommu,
if (pasid != PASID_RID2PASID)
pasid_set_sre(pte);
pasid_set_present(pte);
+ spin_unlock(&iommu->lock);
+
pasid_flush_caches(iommu, pte, pasid, did);

return 0;
@@ -669,15 +672,17 @@ int intel_pasid_setup_pass_through(struct intel_iommu *iommu,
u16 did = FLPT_DEFAULT_DID;
struct pasid_entry *pte;

+ spin_lock(&iommu->lock);
pte = intel_pasid_get_entry(dev, pasid);
if (!pte) {
- dev_err(dev, "Failed to get pasid entry of PASID %d\n", pasid);
+ spin_unlock(&iommu->lock);
return -ENODEV;
}

- /* Caller must ensure PASID entry is not in use. */
- if (pasid_pte_is_present(pte))
+ if (pasid_pte_is_present(pte)) {
+ spin_unlock(&iommu->lock);
return -EBUSY;
+ }

pasid_clear_entry(pte);
pasid_set_domain_id(pte, did);
@@ -692,6 +697,8 @@ int intel_pasid_setup_pass_through(struct intel_iommu *iommu,
*/
pasid_set_sre(pte);
pasid_set_present(pte);
+ spin_unlock(&iommu->lock);
+
pasid_flush_caches(iommu, pte, pasid, did);

return 0;
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 82288a50660d..64072e628bbd 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -394,11 +394,8 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu,
sflags = (flags & SVM_FLAG_SUPERVISOR_MODE) ?
PASID_FLAG_SUPERVISOR_MODE : 0;
sflags |= cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0;
- spin_lock(&iommu->lock);
ret = intel_pasid_setup_first_level(iommu, dev, mm->pgd, mm->pasid,
FLPT_DEFAULT_DID, sflags);
- spin_unlock(&iommu->lock);
-
if (ret)
goto free_sdev;

--
2.25.1