On 2/15/25 01:07, Jason Gunthorpe wrote:
These are called in a lot of places and are not trivial. Move them to the
core module.
Tidy some of the comments and function arguments, fold
__iommu_alloc_account() into its only caller, change
__iommu_free_account() into __iommu_free_page() to remove some
duplication.
Signed-off-by: Jason Gunthorpe<jgg@xxxxxxxxxx>
---
drivers/iommu/Makefile | 1 +
drivers/iommu/iommu-pages.c | 84 +++++++++++++++++++++++++++++
drivers/iommu/iommu-pages.h | 103 ++----------------------------------
3 files changed, 90 insertions(+), 98 deletions(-)
create mode 100644 drivers/iommu/iommu-pages.c
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 5e5a83c6c2aae2..fe91d770abe16c 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
obj-y += amd/ intel/ arm/ iommufd/ riscv/
obj-$(CONFIG_IOMMU_API) += iommu.o
+obj-$(CONFIG_IOMMU_SUPPORT) += iommu-pages.o
obj-$(CONFIG_IOMMU_API) += iommu-traces.o
obj-$(CONFIG_IOMMU_API) += iommu-sysfs.o
obj-$(CONFIG_IOMMU_DEBUGFS) += iommu-debugfs.o
diff --git a/drivers/iommu/iommu-pages.c b/drivers/iommu/iommu-pages.c
new file mode 100644
index 00000000000000..dbf7205bb23dcc
--- /dev/null
+++ b/drivers/iommu/iommu-pages.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024, Google LLC.
+ * Pasha Tatashin<pasha.tatashin@xxxxxxxxxx>
+ */
+#include "iommu-pages.h"
+#include <linux/gfp.h>
+#include <linux/mm.h>
+
+/**
+ * iommu_alloc_pages_node - Allocate a zeroed page of a given order from
+ * specific NUMA node
+ * @nid: memory NUMA node id
+ * @gfp: buddy allocator flags
+ * @order: page order
+ *
+ * Returns the virtual address of the allocated page. The page must be
+ * freed either by calling iommu_free_page() or via iommu_put_pages_list().
nit: ... by calling iommu_free_pages() ...
and
s/page/pages/g in above comments?
+ */
+void *iommu_alloc_pages_node(int nid, gfp_t gfp, unsigned int order)
+{
+ const unsigned long pgcnt = 1UL << order;
+ struct page *page;
+
+ page = alloc_pages_node(nid, gfp | __GFP_ZERO | __GFP_COMP, order);
+ if (unlikely(!page))
+ return NULL;
+
+ /*
+ * All page allocations that should be reported to as "iommu-pagetables"
+ * to userspace must use one of the functions below. This includes
+ * allocations of page-tables and other per-iommu_domain configuration
+ * structures.
+ *
+ * This is necessary for the proper accounting as IOMMU state can be
+ * rather large, i.e. multiple gigabytes in size.
+ */
+ mod_node_page_state(page_pgdat(page), NR_IOMMU_PAGES, pgcnt);
+ mod_lruvec_page_state(page, NR_SECONDARY_PAGETABLE, pgcnt);
+
+ return page_address(page);
+}
+EXPORT_SYMBOL_GPL(iommu_alloc_pages_node);
+
+static void __iommu_free_page(struct page *page)
It's more readable if renaming it to __iommu_free_pages()?
+{
+ unsigned int order = folio_order(page_folio(page));
+ const unsigned long pgcnt = 1UL << order;
+
+ mod_node_page_state(page_pgdat(page), NR_IOMMU_PAGES, -pgcnt);
+ mod_lruvec_page_state(page, NR_SECONDARY_PAGETABLE, -pgcnt);
+ put_page(page);
+}
Thanks,
baolu
