/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
 * This is a module to test the HMM (Heterogeneous Memory Management) API
 * of the kernel. It allows a userspace program to expose its entire address
 * space through the HMM test module device file.
 */
#ifndef _LIB_TEST_HMM_UAPI_H
#define _LIB_TEST_HMM_UAPI_H

#include <linux/types.h>
#include <linux/ioctl.h>

/*
 * Structure to pass to the HMM test driver to mimic a device accessing
 * system memory and ZONE_DEVICE private memory through device page tables.
 *
 * @addr: (in) user address the device will read/write
 * @ptr: (in) user address where device data is copied to/from
 * @npages: (in) number of pages to read/write
 * @cpages: (out) number of pages copied
 * @faults: (out) number of device page faults seen
 */
struct hmm_dmirror_cmd {
        __u64           addr;
        __u64           ptr;
        __u64           npages;
        __u64           cpages;
        __u64           faults;
};

/* Expose the address space of the calling process through hmm device file */
#define HMM_DMIRROR_READ                _IOWR('H', 0x00, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_WRITE               _IOWR('H', 0x01, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_MIGRATE_TO_DEV      _IOWR('H', 0x02, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_MIGRATE_TO_SYS      _IOWR('H', 0x03, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_SNAPSHOT            _IOWR('H', 0x04, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_EXCLUSIVE           _IOWR('H', 0x05, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_CHECK_EXCLUSIVE     _IOWR('H', 0x06, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_RELEASE             _IOWR('H', 0x07, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_FLAGS               _IOWR('H', 0x08, struct hmm_dmirror_cmd)

#define HMM_DMIRROR_FLAG_FAIL_ALLOC     (1ULL << 0)

/*
 * Values returned in hmm_dmirror_cmd.ptr for HMM_DMIRROR_SNAPSHOT.
 * HMM_DMIRROR_PROT_ERROR: no valid mirror PTE for this page
 * HMM_DMIRROR_PROT_NONE: unpopulated PTE or PTE with no access
 * HMM_DMIRROR_PROT_READ: read-only PTE
 * HMM_DMIRROR_PROT_WRITE: read/write PTE
 * HMM_DMIRROR_PROT_PMD: PMD sized page is fully mapped by same permissions
 * HMM_DMIRROR_PROT_PUD: PUD sized page is fully mapped by same permissions
 * HMM_DMIRROR_PROT_ZERO: special read-only zero page
 * HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL: Migrated device private page on the
 *                                      device the ioctl() is made
 * HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE: Migrated device private page on some
 *                                      other device
 * HMM_DMIRROR_PROT_DEV_COHERENT: Migrate device coherent page on the device
 *                                the ioctl() is made
 */
enum {
        HMM_DMIRROR_PROT_ERROR                  = 0xFF,
        HMM_DMIRROR_PROT_NONE                   = 0x00,
        HMM_DMIRROR_PROT_READ                   = 0x01,
        HMM_DMIRROR_PROT_WRITE                  = 0x02,
        HMM_DMIRROR_PROT_PMD                    = 0x04,
        HMM_DMIRROR_PROT_PUD                    = 0x08,
        HMM_DMIRROR_PROT_ZERO                   = 0x10,
        HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL      = 0x20,
        HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE     = 0x30,
        HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL     = 0x40,
        HMM_DMIRROR_PROT_DEV_COHERENT_REMOTE    = 0x50,
};

enum {
        /* 0 is reserved to catch uninitialized type fields */
        HMM_DMIRROR_MEMORY_DEVICE_PRIVATE = 1,
        HMM_DMIRROR_MEMORY_DEVICE_COHERENT,
};

#endif /* _LIB_TEST_HMM_UAPI_H */