[RFC PATCH 08/19] vfio/spapr_tce: Convert accounting to pinned_vm

[Alistair Popple]

Convert from accounting pages against locked_vm to accounting them to
pinned_vm. This allows struct vm_account to be used to track the
mm_struct used to charge the pages. A future change also uses this to
track a cgroup for controlling pinned pages.

Signed-off-by: Alistair Popple <apopple@xxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
Cc: Cornelia Huck <cohuck@xxxxxxxxxx>
Cc: Alexey Kardashevskiy <aik@xxxxxxxxx>
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
---
 arch/powerpc/mm/book3s64/iommu_api.c | 29 ++++++++++++++++++-----------
 drivers/vfio/vfio_iommu_spapr_tce.c  | 15 ++++++++++-----
 2 files changed, 28 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/mm/book3s64/iommu_api.c b/arch/powerpc/mm/book3s64/iommu_api.c
index 7fcfba1..6c57603 100644
--- a/arch/powerpc/mm/book3s64/iommu_api.c
+++ b/arch/powerpc/mm/book3s64/iommu_api.c
@@ -30,6 +30,7 @@ struct mm_iommu_table_group_mem_t {
 	unsigned long used;
 	atomic64_t mapped;
 	unsigned int pageshift;
+	struct vm_account vm_account;
 	u64 ua;			/* userspace address */
 	u64 entries;		/* number of entries in hpas/hpages[] */
 	/*
@@ -62,20 +63,24 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua,
 	unsigned int pageshift;
 	unsigned long entry, chunk;
 
-	if (dev_hpa == MM_IOMMU_TABLE_INVALID_HPA) {
-		ret = account_locked_vm(mm, entries, true);
-		if (ret)
-			return ret;
-
-		locked_entries = entries;
-	}
-
 	mem = kzalloc(sizeof(*mem), GFP_KERNEL);
 	if (!mem) {
 		ret = -ENOMEM;
 		goto unlock_exit;
 	}
 
+	vm_account_init_current(&mem->vm_account);
+	if (dev_hpa == MM_IOMMU_TABLE_INVALID_HPA) {
+		ret = vm_account_pinned(&mem->vm_account, entries);
+		if (ret) {
+			vm_account_release(&mem->vm_account);
+			kfree(mem);
+			return ret;
+		}
+
+		locked_entries = entries;
+	}
+
 	if (dev_hpa != MM_IOMMU_TABLE_INVALID_HPA) {
 		mem->pageshift = __ffs(dev_hpa | (entries << PAGE_SHIFT));
 		mem->dev_hpa = dev_hpa;
@@ -175,10 +180,11 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua,
 	unpin_user_pages(mem->hpages, pinned);
 
 	vfree(mem->hpas);
-	kfree(mem);
 
 unlock_exit:
-	account_locked_vm(mm, locked_entries, false);
+	vm_unaccount_pinned(&mem->vm_account, locked_entries);
+	vm_account_release(&mem->vm_account);
+	kfree(mem);
 
 	return ret;
 }
@@ -229,6 +235,7 @@ static void mm_iommu_do_free(struct mm_iommu_table_group_mem_t *mem)
 
 	mm_iommu_unpin(mem);
 	vfree(mem->hpas);
+	vm_account_release(&mem->vm_account);
 	kfree(mem);
 }
 
@@ -279,7 +286,7 @@ long mm_iommu_put(struct mm_struct *mm, struct mm_iommu_table_group_mem_t *mem)
 unlock_exit:
 	mutex_unlock(&mem_list_mutex);
 
-	account_locked_vm(mm, unlock_entries, false);
+	vm_unaccount_pinned(&mem->vm_account, unlock_entries);
 
 	return ret;
 }
diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index 60a50ce..a58281b 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -67,6 +67,7 @@ struct tce_container {
 	bool def_window_pending;
 	unsigned long locked_pages;
 	struct mm_struct *mm;
+	struct vm_account vm_account;
 	struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES];
 	struct list_head group_list;
 	struct list_head prereg_list;
@@ -82,6 +83,7 @@ static long tce_iommu_mm_set(struct tce_container *container)
 	BUG_ON(!current->mm);
 	container->mm = current->mm;
 	mmgrab(container->mm);
+	vm_account_init_current(&container->vm_account);
 
 	return 0;
 }
@@ -291,7 +293,7 @@ static int tce_iommu_enable(struct tce_container *container)
 		return ret;
 
 	locked = table_group->tce32_size >> PAGE_SHIFT;
-	ret = account_locked_vm(container->mm, locked, true);
+	ret = vm_account_pinned(&container->vm_accounnt, locked);
 	if (ret)
 		return ret;
 
@@ -310,7 +312,7 @@ static void tce_iommu_disable(struct tce_container *container)
 	container->enabled = false;
 
 	BUG_ON(!container->mm);
-	account_locked_vm(container->mm, container->locked_pages, false);
+	vm_account_pinned(&container->vm_account, container->locked_pages);
 }
 
 static void *tce_iommu_open(unsigned long arg)
@@ -372,8 +374,10 @@ static void tce_iommu_release(void *iommu_data)
 		WARN_ON(tce_iommu_prereg_free(container, tcemem));
 
 	tce_iommu_disable(container);
-	if (container->mm)
+	if (container->mm) {
 		mmdrop(container->mm);
+		vm_account_release(&container->vm_account);
+	}
 	mutex_destroy(&container->lock);
 
 	kfree(container);
@@ -619,7 +623,8 @@ static long tce_iommu_create_table(struct tce_container *container,
 	if (!table_size)
 		return -EINVAL;
 
-	ret = account_locked_vm(container->mm, table_size >> PAGE_SHIFT, true);
+	ret = vm_account_pinned(&container->vm_account,
+				table_size >> PAGE_SHIFT);
 	if (ret)
 		return ret;
 
@@ -638,7 +643,7 @@ static void tce_iommu_free_table(struct tce_container *container,
 	unsigned long pages = tbl->it_allocated_size >> PAGE_SHIFT;
 
 	iommu_tce_table_put(tbl);
-	account_locked_vm(container->mm, pages, false);
+	vm_unaccount_pinned(&container->vm_account, pages);
 }
 
 static long tce_iommu_create_window(struct tce_container *container,
-- 
git-series 0.9.1