xref: /openbmc/linux/io_uring/filetable.h (revision 453b329b)
1 // SPDX-License-Identifier: GPL-2.0
2 #ifndef IOU_FILE_TABLE_H
3 #define IOU_FILE_TABLE_H
4 
5 struct io_ring_ctx;
6 
7 /*
8  * FFS_SCM is only available on 64-bit archs, for 32-bit we just define it as 0
9  * and define IO_URING_SCM_ALL. For this case, we use SCM for all files as we
10  * can't safely always dereference the file when the task has exited and ring
11  * cleanup is done. If a file is tracked and part of SCM, then unix gc on
12  * process exit may reap it before __io_sqe_files_unregister() is run.
13  */
14 #define FFS_NOWAIT		0x1UL
15 #define FFS_ISREG		0x2UL
16 #if defined(CONFIG_64BIT)
17 #define FFS_SCM			0x4UL
18 #else
19 #define IO_URING_SCM_ALL
20 #define FFS_SCM			0x0UL
21 #endif
22 #define FFS_MASK		~(FFS_NOWAIT|FFS_ISREG|FFS_SCM)
23 
24 struct io_fixed_file {
25 	/* file * with additional FFS_* flags */
26 	unsigned long file_ptr;
27 };
28 
29 struct io_file_table {
30 	struct io_fixed_file *files;
31 	unsigned long *bitmap;
32 	unsigned int alloc_hint;
33 };
34 
35 bool io_alloc_file_tables(struct io_file_table *table, unsigned nr_files);
36 void io_free_file_tables(struct io_file_table *table);
37 int io_file_bitmap_get(struct io_ring_ctx *ctx);
38 
39 static inline void io_file_bitmap_clear(struct io_file_table *table, int bit)
40 {
41 	__clear_bit(bit, table->bitmap);
42 	table->alloc_hint = bit;
43 }
44 
45 static inline void io_file_bitmap_set(struct io_file_table *table, int bit)
46 {
47 	WARN_ON_ONCE(test_bit(bit, table->bitmap));
48 	__set_bit(bit, table->bitmap);
49 	table->alloc_hint = bit + 1;
50 }
51 
52 static inline struct io_fixed_file *
53 io_fixed_file_slot(struct io_file_table *table, unsigned i)
54 {
55 	return &table->files[i];
56 }
57 
58 #endif
59