xref: /openbmc/linux/lib/test_hmm_uapi.h (revision b737eecd)
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  */
23 struct 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		_IOWR('H', 0x02, struct hmm_dmirror_cmd)
35 #define HMM_DMIRROR_SNAPSHOT		_IOWR('H', 0x03, struct hmm_dmirror_cmd)
36 
37 /*
38  * Values returned in hmm_dmirror_cmd.ptr for HMM_DMIRROR_SNAPSHOT.
39  * HMM_DMIRROR_PROT_ERROR: no valid mirror PTE for this page
40  * HMM_DMIRROR_PROT_NONE: unpopulated PTE or PTE with no access
41  * HMM_DMIRROR_PROT_READ: read-only PTE
42  * HMM_DMIRROR_PROT_WRITE: read/write PTE
43  * HMM_DMIRROR_PROT_PMD: PMD sized page is fully mapped by same permissions
44  * HMM_DMIRROR_PROT_PUD: PUD sized page is fully mapped by same permissions
45  * HMM_DMIRROR_PROT_ZERO: special read-only zero page
46  * HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL: Migrated device private page on the
47  *					device the ioctl() is made
48  * HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE: Migrated device private page on some
49  *					other device
50  */
51 enum {
52 	HMM_DMIRROR_PROT_ERROR			= 0xFF,
53 	HMM_DMIRROR_PROT_NONE			= 0x00,
54 	HMM_DMIRROR_PROT_READ			= 0x01,
55 	HMM_DMIRROR_PROT_WRITE			= 0x02,
56 	HMM_DMIRROR_PROT_PMD			= 0x04,
57 	HMM_DMIRROR_PROT_PUD			= 0x08,
58 	HMM_DMIRROR_PROT_ZERO			= 0x10,
59 	HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL	= 0x20,
60 	HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE	= 0x30,
61 };
62 
63 #endif /* _LIB_TEST_HMM_UAPI_H */
64