Commit 99ff06dc authored by Steve Sistare's avatar Steve Sistare Committed by Jason Gunthorpe
Browse files

iommufd: Generalize iopt_pages address 

The starting address in iopt_pages is currently a __user *uptr.
Generalize to allow other types of addresses.  Refactor iopt_alloc_pages()
and iopt_map_user_pages() into address-type specific and common functions.

Link: https://patch.msgid.link/r/1729861919-234514-4-git-send-email-steven.sistare@oracle.com


Suggested-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Signed-off-by: default avatarSteve Sistare <steven.sistare@oracle.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 32383c08

drivers/iommu/iommufd/io_pagetable.c

+34 −21
Original line number Diff line number Diff line
@@ -384,6 +384,34 @@ int iopt_map_pages(struct io_pagetable *iopt, struct list_head *pages_list, 
	return rc;

}



static int iopt_map_common(struct iommufd_ctx *ictx, struct io_pagetable *iopt,

			   struct iopt_pages *pages, unsigned long *iova,

			   unsigned long length, unsigned long start_byte,

			   int iommu_prot, unsigned int flags)

{

	struct iopt_pages_list elm = {};

	LIST_HEAD(pages_list);

	int rc;



	elm.pages = pages;

	elm.start_byte = start_byte;

	if (ictx->account_mode == IOPT_PAGES_ACCOUNT_MM &&

	    elm.pages->account_mode == IOPT_PAGES_ACCOUNT_USER)

		elm.pages->account_mode = IOPT_PAGES_ACCOUNT_MM;

	elm.length = length;

	list_add(&elm.next, &pages_list);



	rc = iopt_map_pages(iopt, &pages_list, length, iova, iommu_prot, flags);

	if (rc) {

		if (elm.area)

			iopt_abort_area(elm.area);

		if (elm.pages)

			iopt_put_pages(elm.pages);

		return rc;

	}

	return 0;

}



/**

 * iopt_map_user_pages() - Map a user VA to an iova in the io page table

 * @ictx: iommufd_ctx the iopt is part of
@@ -408,29 +436,14 @@ int iopt_map_user_pages(struct iommufd_ctx *ictx, struct io_pagetable *iopt, 
			unsigned long length, int iommu_prot,

			unsigned int flags)

{

	struct iopt_pages_list elm = {};

	LIST_HEAD(pages_list);

	int rc;

	struct iopt_pages *pages;



	elm.pages = iopt_alloc_pages(uptr, length, iommu_prot & IOMMU_WRITE);

	if (IS_ERR(elm.pages))

		return PTR_ERR(elm.pages);

	if (ictx->account_mode == IOPT_PAGES_ACCOUNT_MM &&

	    elm.pages->account_mode == IOPT_PAGES_ACCOUNT_USER)

		elm.pages->account_mode = IOPT_PAGES_ACCOUNT_MM;

	elm.start_byte = uptr - elm.pages->uptr;

	elm.length = length;

	list_add(&elm.next, &pages_list);

	pages = iopt_alloc_user_pages(uptr, length, iommu_prot & IOMMU_WRITE);

	if (IS_ERR(pages))

		return PTR_ERR(pages);



	rc = iopt_map_pages(iopt, &pages_list, length, iova, iommu_prot, flags);

	if (rc) {

		if (elm.area)

			iopt_abort_area(elm.area);

		if (elm.pages)

			iopt_put_pages(elm.pages);

		return rc;

	}

	return 0;

	return iopt_map_common(ictx, iopt, pages, iova, length,

			       uptr - pages->uptr, iommu_prot, flags);

}



struct iova_bitmap_fn_arg {

drivers/iommu/iommufd/io_pagetable.h

+10 −3
Original line number Diff line number Diff line
@@ -175,6 +175,10 @@ enum { 
	IOPT_PAGES_ACCOUNT_MM = 2,

};



enum iopt_address_type {

	IOPT_ADDRESS_USER = 0,

};



/*

 * This holds a pinned page list for multiple areas of IO address space. The

 * pages always originate from a linear chunk of userspace VA. Multiple
@@ -195,7 +199,10 @@ struct iopt_pages { 
	struct task_struct *source_task;

	struct mm_struct *source_mm;

	struct user_struct *source_user;

	void __user *uptr;

	enum iopt_address_type type;

	union {

		void __user *uptr;		/* IOPT_ADDRESS_USER */

	};

	bool writable:1;

	u8 account_mode;
@@ -206,8 +213,8 @@ struct iopt_pages { 
	struct rb_root_cached domains_itree;

};



struct iopt_pages *iopt_alloc_pages(void __user *uptr, unsigned long length,

				    bool writable);

struct iopt_pages *iopt_alloc_user_pages(void __user *uptr,

					 unsigned long length, bool writable);

void iopt_release_pages(struct kref *kref);

static inline void iopt_put_pages(struct iopt_pages *pages)

{

drivers/iommu/iommufd/pages.c

+23 −8
Original line number Diff line number Diff line
@@ -1139,11 +1139,11 @@ static int pfn_reader_first(struct pfn_reader *pfns, struct iopt_pages *pages, 
	return 0;

}



struct iopt_pages *iopt_alloc_pages(void __user *uptr, unsigned long length,

static struct iopt_pages *iopt_alloc_pages(unsigned long start_byte,

					   unsigned long length,

					   bool writable)

{

	struct iopt_pages *pages;

	unsigned long end;



	/*

	 * The iommu API uses size_t as the length, and protect the DIV_ROUND_UP
@@ -1152,9 +1152,6 @@ struct iopt_pages *iopt_alloc_pages(void __user *uptr, unsigned long length, 
	if (length > SIZE_MAX - PAGE_SIZE || length == 0)

		return ERR_PTR(-EINVAL);



	if (check_add_overflow((unsigned long)uptr, length, &end))

		return ERR_PTR(-EOVERFLOW);



	pages = kzalloc(sizeof(*pages), GFP_KERNEL_ACCOUNT);

	if (!pages)

		return ERR_PTR(-ENOMEM);
@@ -1164,8 +1161,7 @@ struct iopt_pages *iopt_alloc_pages(void __user *uptr, unsigned long length, 
	mutex_init(&pages->mutex);

	pages->source_mm = current->mm;

	mmgrab(pages->source_mm);

	pages->uptr = (void __user *)ALIGN_DOWN((uintptr_t)uptr, PAGE_SIZE);

	pages->npages = DIV_ROUND_UP(length + (uptr - pages->uptr), PAGE_SIZE);

	pages->npages = DIV_ROUND_UP(length + start_byte, PAGE_SIZE);

	pages->access_itree = RB_ROOT_CACHED;

	pages->domains_itree = RB_ROOT_CACHED;

	pages->writable = writable;
@@ -1179,6 +1175,25 @@ struct iopt_pages *iopt_alloc_pages(void __user *uptr, unsigned long length, 
	return pages;

}



struct iopt_pages *iopt_alloc_user_pages(void __user *uptr,

					 unsigned long length, bool writable)

{

	struct iopt_pages *pages;

	unsigned long end;

	void __user *uptr_down =

		(void __user *) ALIGN_DOWN((uintptr_t)uptr, PAGE_SIZE);



	if (check_add_overflow((unsigned long)uptr, length, &end))

		return ERR_PTR(-EOVERFLOW);



	pages = iopt_alloc_pages(uptr - uptr_down, length, writable);

	if (IS_ERR(pages))

		return pages;

	pages->uptr = uptr_down;

	pages->type = IOPT_ADDRESS_USER;

	return pages;

}



void iopt_release_pages(struct kref *kref)

{

	struct iopt_pages *pages = container_of(kref, struct iopt_pages, kref);