lib/test_hmm_uapi.h

   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 */