Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 212 insertions, 0 deletions

diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
new file mode 100644
index 000000000..b78671a8a
--- /dev/null
+++ b/drivers/iommu/iommu-sva.c
@@ -0,0 +1,212 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Helpers for IOMMU drivers implementing SVA
+ */
+#include <linux/mmu_context.h>
+#include <linux/mutex.h>
+#include <linux/sched/mm.h>
+#include <linux/iommu.h>
+
+#include "iommu-sva.h"
+
+static DEFINE_MUTEX(iommu_sva_lock);
+
+/* Allocate a PASID for the mm within range (inclusive) */
+static int iommu_sva_alloc_pasid(struct mm_struct *mm, struct device *dev)
+{
+	ioasid_t pasid;
+	int ret = 0;
+
+	if (!arch_pgtable_dma_compat(mm))
+		return -EBUSY;
+
+	mutex_lock(&iommu_sva_lock);
+	/* Is a PASID already associated with this mm? */
+	if (mm_valid_pasid(mm)) {
+		if (mm->pasid >= dev->iommu->max_pasids)
+			ret = -EOVERFLOW;
+		goto out;
+	}
+
+	pasid = iommu_alloc_global_pasid(dev);
+	if (pasid == IOMMU_PASID_INVALID) {
+		ret = -ENOSPC;
+		goto out;
+	}
+	mm->pasid = pasid;
+	ret = 0;
+out:
+	mutex_unlock(&iommu_sva_lock);
+	return ret;
+}
+
+/**
+ * iommu_sva_bind_device() - Bind a process address space to a device
+ * @dev: the device
+ * @mm: the mm to bind, caller must hold a reference to mm_users
+ *
+ * Create a bond between device and address space, allowing the device to
+ * access the mm using the PASID returned by iommu_sva_get_pasid(). If a
+ * bond already exists between @device and @mm, an additional internal
+ * reference is taken. Caller must call iommu_sva_unbind_device()
+ * to release each reference.
+ *
+ * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to
+ * initialize the required SVA features.
+ *
+ * On error, returns an ERR_PTR value.
+ */
+struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm)
+{
+	struct iommu_domain *domain;
+	struct iommu_sva *handle;
+	int ret;
+
+	/* Allocate mm->pasid if necessary. */
+	ret = iommu_sva_alloc_pasid(mm, dev);
+	if (ret)
+		return ERR_PTR(ret);
+
+	handle = kzalloc(sizeof(*handle), GFP_KERNEL);
+	if (!handle)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_lock(&iommu_sva_lock);
+	/* Search for an existing domain. */
+	domain = iommu_get_domain_for_dev_pasid(dev, mm->pasid,
+						IOMMU_DOMAIN_SVA);
+	if (IS_ERR(domain)) {
+		ret = PTR_ERR(domain);
+		goto out_unlock;
+	}
+
+	if (domain) {
+		domain->users++;
+		goto out;
+	}
+
+	/* Allocate a new domain and set it on device pasid. */
+	domain = iommu_sva_domain_alloc(dev, mm);
+	if (!domain) {
+		ret = -ENOMEM;
+		goto out_unlock;
+	}
+
+	ret = iommu_attach_device_pasid(domain, dev, mm->pasid);
+	if (ret)
+		goto out_free_domain;
+	domain->users = 1;
+out:
+	mutex_unlock(&iommu_sva_lock);
+	handle->dev = dev;
+	handle->domain = domain;
+
+	return handle;
+
+out_free_domain:
+	iommu_domain_free(domain);
+out_unlock:
+	mutex_unlock(&iommu_sva_lock);
+	kfree(handle);
+
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(iommu_sva_bind_device);
+
+/**
+ * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device
+ * @handle: the handle returned by iommu_sva_bind_device()
+ *
+ * Put reference to a bond between device and address space. The device should
+ * not be issuing any more transaction for this PASID. All outstanding page
+ * requests for this PASID must have been flushed to the IOMMU.
+ */
+void iommu_sva_unbind_device(struct iommu_sva *handle)
+{
+	struct iommu_domain *domain = handle->domain;
+	ioasid_t pasid = domain->mm->pasid;
+	struct device *dev = handle->dev;
+
+	mutex_lock(&iommu_sva_lock);
+	if (--domain->users == 0) {
+		iommu_detach_device_pasid(domain, dev, pasid);
+		iommu_domain_free(domain);
+	}
+	mutex_unlock(&iommu_sva_lock);
+	kfree(handle);
+}
+EXPORT_SYMBOL_GPL(iommu_sva_unbind_device);
+
+u32 iommu_sva_get_pasid(struct iommu_sva *handle)
+{
+	struct iommu_domain *domain = handle->domain;
+
+	return domain->mm->pasid;
+}
+EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
+
+/*
+ * I/O page fault handler for SVA
+ */
+enum iommu_page_response_code
+iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
+{
+	vm_fault_t ret;
+	struct vm_area_struct *vma;
+	struct mm_struct *mm = data;
+	unsigned int access_flags = 0;
+	unsigned int fault_flags = FAULT_FLAG_REMOTE;
+	struct iommu_fault_page_request *prm = &fault->prm;
+	enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID;
+
+	if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID))
+		return status;
+
+	if (!mmget_not_zero(mm))
+		return status;
+
+	mmap_read_lock(mm);
+
+	vma = vma_lookup(mm, prm->addr);
+	if (!vma)
+		/* Unmapped area */
+		goto out_put_mm;
+
+	if (prm->perm & IOMMU_FAULT_PERM_READ)
+		access_flags |= VM_READ;
+
+	if (prm->perm & IOMMU_FAULT_PERM_WRITE) {
+		access_flags |= VM_WRITE;
+		fault_flags |= FAULT_FLAG_WRITE;
+	}
+
+	if (prm->perm & IOMMU_FAULT_PERM_EXEC) {
+		access_flags |= VM_EXEC;
+		fault_flags |= FAULT_FLAG_INSTRUCTION;
+	}
+
+	if (!(prm->perm & IOMMU_FAULT_PERM_PRIV))
+		fault_flags |= FAULT_FLAG_USER;
+
+	if (access_flags & ~vma->vm_flags)
+		/* Access fault */
+		goto out_put_mm;
+
+	ret = handle_mm_fault(vma, prm->addr, fault_flags, NULL);
+	status = ret & VM_FAULT_ERROR ? IOMMU_PAGE_RESP_INVALID :
+		IOMMU_PAGE_RESP_SUCCESS;
+
+out_put_mm:
+	mmap_read_unlock(mm);
+	mmput(mm);
+
+	return status;
+}
+
+void mm_pasid_drop(struct mm_struct *mm)
+{
+	if (likely(!mm_valid_pasid(mm)))
+		return;
+
+	iommu_free_global_pasid(mm->pasid);
+}