1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2/*
3 * This is a module to test the HMM (Heterogeneous Memory Management) API
4 * of the kernel. It allows a userspace program to expose its entire address
5 * space through the HMM test module device file.
6 */
7#ifndef _LIB_TEST_HMM_UAPI_H
8#define _LIB_TEST_HMM_UAPI_H
9
10#include <linux/types.h>
11#include <linux/ioctl.h>
12
13/*
14 * Structure to pass to the HMM test driver to mimic a device accessing
15 * system memory and ZONE_DEVICE private memory through device page tables.
16 *
17 * @addr: (in) user address the device will read/write
18 * @ptr: (in) user address where device data is copied to/from
19 * @npages: (in) number of pages to read/write
20 * @cpages: (out) number of pages copied
21 * @faults: (out) number of device page faults seen
22 */
23struct hmm_dmirror_cmd {
24 __u64 addr;
25 __u64 ptr;
26 __u64 npages;
27 __u64 cpages;
28 __u64 faults;
29};
30
31/* Expose the address space of the calling process through hmm device file */
32#define HMM_DMIRROR_READ _IOWR('H', 0x00, struct hmm_dmirror_cmd)
33#define HMM_DMIRROR_WRITE _IOWR('H', 0x01, struct hmm_dmirror_cmd)
34#define HMM_DMIRROR_MIGRATE_TO_DEV _IOWR('H', 0x02, struct hmm_dmirror_cmd)
35#define HMM_DMIRROR_MIGRATE_TO_SYS _IOWR('H', 0x03, struct hmm_dmirror_cmd)
36#define HMM_DMIRROR_SNAPSHOT _IOWR('H', 0x04, struct hmm_dmirror_cmd)
37#define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd)
38#define HMM_DMIRROR_CHECK_EXCLUSIVE _IOWR('H', 0x06, struct hmm_dmirror_cmd)
39#define HMM_DMIRROR_RELEASE _IOWR('H', 0x07, struct hmm_dmirror_cmd)
40
41/*
42 * Values returned in hmm_dmirror_cmd.ptr for HMM_DMIRROR_SNAPSHOT.
43 * HMM_DMIRROR_PROT_ERROR: no valid mirror PTE for this page
44 * HMM_DMIRROR_PROT_NONE: unpopulated PTE or PTE with no access
45 * HMM_DMIRROR_PROT_READ: read-only PTE
46 * HMM_DMIRROR_PROT_WRITE: read/write PTE
47 * HMM_DMIRROR_PROT_PMD: PMD sized page is fully mapped by same permissions
48 * HMM_DMIRROR_PROT_PUD: PUD sized page is fully mapped by same permissions
49 * HMM_DMIRROR_PROT_ZERO: special read-only zero page
50 * HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL: Migrated device private page on the
51 * device the ioctl() is made
52 * HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE: Migrated device private page on some
53 * other device
54 * HMM_DMIRROR_PROT_DEV_COHERENT: Migrate device coherent page on the device
55 * the ioctl() is made
56 */
57enum {
58 HMM_DMIRROR_PROT_ERROR = 0xFF,
59 HMM_DMIRROR_PROT_NONE = 0x00,
60 HMM_DMIRROR_PROT_READ = 0x01,
61 HMM_DMIRROR_PROT_WRITE = 0x02,
62 HMM_DMIRROR_PROT_PMD = 0x04,
63 HMM_DMIRROR_PROT_PUD = 0x08,
64 HMM_DMIRROR_PROT_ZERO = 0x10,
65 HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL = 0x20,
66 HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE = 0x30,
67 HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL = 0x40,
68 HMM_DMIRROR_PROT_DEV_COHERENT_REMOTE = 0x50,
69};
70
71enum {
72 /* 0 is reserved to catch uninitialized type fields */
73 HMM_DMIRROR_MEMORY_DEVICE_PRIVATE = 1,
74 HMM_DMIRROR_MEMORY_DEVICE_COHERENT,
75};
76
77#endif /* _LIB_TEST_HMM_UAPI_H */
78

source code of linux/lib/test_hmm_uapi.h