Implement the iommu_get/put_single_reserved API in arm-smmu.
In order to track which physical address is already mapped we
use the RB tree indexed by PA.
Signed-off-by: Eric Auger <eric.au...@linaro.org>
---
v1 -> v2:
- previously in vfio_iommu_type1.c
---
drivers/iommu/arm-smmu.c | 114 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 114 insertions(+)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 729a4c6..9961bfd 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1563,6 +1563,118 @@ static void arm_smmu_free_reserved_iova_domain(struct
iommu_domain *domain)
mutex_unlock(&smmu_domain->reserved_mutex);
}
+static int arm_smmu_get_single_reserved(struct iommu_domain *domain,
+ phys_addr_t addr, int prot,
+ dma_addr_t *iova)
+{
+ struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
+ unsigned long order = __ffs(domain->ops->pgsize_bitmap);
+ size_t page_size = 1 << order;
+ phys_addr_t mask = page_size - 1;
+ phys_addr_t aligned_addr = addr & ~mask;
+ phys_addr_t offset = addr - aligned_addr;
+ struct arm_smmu_reserved_binding *b;
+ struct iova *p_iova;
+ struct iova_domain *iovad = smmu_domain->reserved_iova_domain;
+ int ret;
+
+ if (!iovad)
+ return -EINVAL;
+
+ mutex_lock(&smmu_domain->reserved_mutex);
+
+ b = find_reserved_binding(smmu_domain, aligned_addr, page_size);
+ if (b) {
+ *iova = b->iova + offset;
+ kref_get(&b->kref);
+ ret = 0;
+ goto unlock;
+ }
+
+ /* there is no existing reserved iova for this pa */
+ p_iova = alloc_iova(iovad, 1, iovad->dma_32bit_pfn, true);
+ if (!p_iova) {
+ ret = -ENOMEM;
+ goto unlock;
+ }
+ *iova = p_iova->pfn_lo << order;
+
+ b = kzalloc(sizeof(*b), GFP_KERNEL);
+ if (!b) {
+ ret = -ENOMEM;
+ goto free_iova_unlock;
+ }
+
+ ret = arm_smmu_map(domain, *iova, aligned_addr, page_size, prot);
+ if (ret)
+ goto free_binding_iova_unlock;
+
+ kref_init(&b->kref);
+ kref_get(&b->kref);
+ b->domain = smmu_domain;
+ b->addr = aligned_addr;
+ b->iova = *iova;
+ b->size = page_size;
+
+ link_reserved_binding(smmu_domain, b);
+
+ *iova += offset;
+ goto unlock;
+
+free_binding_iova_unlock:
+ kfree(b);
+free_iova_unlock:
+ free_iova(smmu_domain->reserved_iova_domain, *iova >> order);
+unlock:
+ mutex_unlock(&smmu_domain->reserved_mutex);
+ return ret;
+}
+
+/* called with reserved_mutex locked */
+static void reserved_binding_release(struct kref *kref)
+{
+ struct arm_smmu_reserved_binding *b =
+ container_of(kref, struct arm_smmu_reserved_binding, kref);
+ struct arm_smmu_domain *smmu_domain = b->domain;
+ struct iommu_domain *d = &smmu_domain->domain;
+ unsigned long order = __ffs(b->size);
+
+
+ arm_smmu_unmap(d, b->iova, b->size);
+ free_iova(smmu_domain->reserved_iova_domain, b->iova >> order);
+ unlink_reserved_binding(smmu_domain, b);
+ kfree(b);
+}
+
+static void arm_smmu_put_single_reserved(struct iommu_domain *domain,
+ dma_addr_t iova)
+{
+ unsigned long order;
+ phys_addr_t aligned_addr;
+ dma_addr_t aligned_iova, page_size, mask, offset;
+ struct arm_smmu_reserved_binding *b;
+ struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
+
+ order = __ffs(domain->ops->pgsize_bitmap);
+ page_size = (uint64_t)1 << order;
+ mask = page_size - 1;
+
+ aligned_iova = iova & ~mask;
+ offset = iova - aligned_iova;
+
+ aligned_addr = iommu_iova_to_phys(domain, aligned_iova);
+
+ mutex_lock(&smmu_domain->reserved_mutex);
+
+ b = find_reserved_binding(smmu_domain, aligned_addr, page_size);
+ if (!b)
+ goto unlock;
+ kref_put(&b->kref, reserved_binding_release);
+
+unlock:
+ mutex_unlock(&smmu_domain->reserved_mutex);
+}
+
static struct iommu_ops arm_smmu_ops = {
.capable = arm_smmu_capable,
.domain_alloc = arm_smmu_domain_alloc,
@@ -1580,6 +1692,8 @@ static struct iommu_ops arm_smmu_ops = {
.domain_set_attr = arm_smmu_domain_set_attr,
.alloc_reserved_iova_domain = arm_smmu_alloc_reserved_iova_domain,
.free_reserved_iova_domain = arm_smmu_free_reserved_iova_domain,
+ .get_single_reserved = arm_smmu_get_single_reserved,
+ .put_single_reserved = arm_smmu_put_single_reserved,
/* Page size bitmap, restricted during device attach */
.pgsize_bitmap = -1UL,
};
--
1.9.1
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