187 lines
		
	
	
		
			4.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			187 lines
		
	
	
		
			4.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0-only */
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| /*
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|  * Copyright (c) 2024, Google LLC.
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|  * Pasha Tatashin <pasha.tatashin@soleen.com>
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|  */
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| 
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| #ifndef __IOMMU_PAGES_H
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| #define __IOMMU_PAGES_H
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| 
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| #include <linux/vmstat.h>
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| #include <linux/gfp.h>
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| #include <linux/mm.h>
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| 
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| /*
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|  * All page allocations that should be reported to as "iommu-pagetables" to
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|  * userspace must use one of the functions below.  This includes allocations of
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|  * page-tables and other per-iommu_domain configuration structures.
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|  *
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|  * This is necessary for the proper accounting as IOMMU state can be rather
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|  * large, i.e. multiple gigabytes in size.
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|  */
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| 
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| /**
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|  * __iommu_alloc_account - account for newly allocated page.
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|  * @page: head struct page of the page.
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|  * @order: order of the page
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|  */
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| static inline void __iommu_alloc_account(struct page *page, int order)
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| {
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| 	const long pgcnt = 1l << order;
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| 
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| 	mod_node_page_state(page_pgdat(page), NR_IOMMU_PAGES, pgcnt);
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| 	mod_lruvec_page_state(page, NR_SECONDARY_PAGETABLE, pgcnt);
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| }
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| 
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| /**
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|  * __iommu_free_account - account a page that is about to be freed.
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|  * @page: head struct page of the page.
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|  * @order: order of the page
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|  */
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| static inline void __iommu_free_account(struct page *page, int order)
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| {
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| 	const long pgcnt = 1l << order;
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| 
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| 	mod_node_page_state(page_pgdat(page), NR_IOMMU_PAGES, -pgcnt);
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| 	mod_lruvec_page_state(page, NR_SECONDARY_PAGETABLE, -pgcnt);
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| }
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| 
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| /**
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|  * __iommu_alloc_pages - allocate a zeroed page of a given order.
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|  * @gfp: buddy allocator flags
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|  * @order: page order
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|  *
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|  * returns the head struct page of the allocated page.
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|  */
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| static inline struct page *__iommu_alloc_pages(gfp_t gfp, int order)
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| {
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| 	struct page *page;
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| 
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| 	page = alloc_pages(gfp | __GFP_ZERO, order);
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| 	if (unlikely(!page))
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| 		return NULL;
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| 
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| 	__iommu_alloc_account(page, order);
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| 
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| 	return page;
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| }
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| 
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| /**
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|  * __iommu_free_pages - free page of a given order
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|  * @page: head struct page of the page
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|  * @order: page order
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|  */
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| static inline void __iommu_free_pages(struct page *page, int order)
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| {
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| 	if (!page)
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| 		return;
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| 
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| 	__iommu_free_account(page, order);
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| 	__free_pages(page, order);
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| }
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| 
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| /**
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|  * iommu_alloc_pages_node - allocate a zeroed page of a given order from
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|  * specific NUMA node.
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|  * @nid: memory NUMA node id
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|  * @gfp: buddy allocator flags
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|  * @order: page order
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|  *
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|  * returns the virtual address of the allocated page
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|  */
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| static inline void *iommu_alloc_pages_node(int nid, gfp_t gfp, int order)
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| {
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| 	struct page *page = alloc_pages_node(nid, gfp | __GFP_ZERO, order);
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| 
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| 	if (unlikely(!page))
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| 		return NULL;
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| 
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| 	__iommu_alloc_account(page, order);
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| 
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| 	return page_address(page);
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| }
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| 
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| /**
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|  * iommu_alloc_pages - allocate a zeroed page of a given order
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|  * @gfp: buddy allocator flags
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|  * @order: page order
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|  *
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|  * returns the virtual address of the allocated page
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|  */
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| static inline void *iommu_alloc_pages(gfp_t gfp, int order)
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| {
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| 	struct page *page = __iommu_alloc_pages(gfp, order);
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| 
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| 	if (unlikely(!page))
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| 		return NULL;
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| 
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| 	return page_address(page);
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| }
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| 
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| /**
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|  * iommu_alloc_page_node - allocate a zeroed page at specific NUMA node.
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|  * @nid: memory NUMA node id
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|  * @gfp: buddy allocator flags
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|  *
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|  * returns the virtual address of the allocated page
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|  */
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| static inline void *iommu_alloc_page_node(int nid, gfp_t gfp)
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| {
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| 	return iommu_alloc_pages_node(nid, gfp, 0);
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| }
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| 
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| /**
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|  * iommu_alloc_page - allocate a zeroed page
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|  * @gfp: buddy allocator flags
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|  *
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|  * returns the virtual address of the allocated page
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|  */
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| static inline void *iommu_alloc_page(gfp_t gfp)
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| {
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| 	return iommu_alloc_pages(gfp, 0);
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| }
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| 
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| /**
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|  * iommu_free_pages - free page of a given order
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|  * @virt: virtual address of the page to be freed.
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|  * @order: page order
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|  */
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| static inline void iommu_free_pages(void *virt, int order)
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| {
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| 	if (!virt)
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| 		return;
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| 
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| 	__iommu_free_pages(virt_to_page(virt), order);
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| }
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| 
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| /**
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|  * iommu_free_page - free page
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|  * @virt: virtual address of the page to be freed.
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|  */
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| static inline void iommu_free_page(void *virt)
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| {
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| 	iommu_free_pages(virt, 0);
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| }
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| 
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| /**
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|  * iommu_put_pages_list - free a list of pages.
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|  * @page: the head of the lru list to be freed.
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|  *
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|  * There are no locking requirement for these pages, as they are going to be
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|  * put on a free list as soon as refcount reaches 0. Pages are put on this LRU
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|  * list once they are removed from the IOMMU page tables. However, they can
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|  * still be access through debugfs.
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|  */
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| static inline void iommu_put_pages_list(struct list_head *page)
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| {
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| 	while (!list_empty(page)) {
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| 		struct page *p = list_entry(page->prev, struct page, lru);
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| 
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| 		list_del(&p->lru);
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| 		__iommu_free_account(p, 0);
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| 		put_page(p);
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| 	}
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| }
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| 
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| #endif	/* __IOMMU_PAGES_H */
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