linux/lib/test_hmm_uapi.h

/* 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 { … };

/* Expose the address space of the calling process through hmm device file */
#define HMM_DMIRROR_READ …
#define HMM_DMIRROR_WRITE …
#define HMM_DMIRROR_MIGRATE_TO_DEV …
#define HMM_DMIRROR_MIGRATE_TO_SYS …
#define HMM_DMIRROR_SNAPSHOT …
#define HMM_DMIRROR_EXCLUSIVE …
#define HMM_DMIRROR_CHECK_EXCLUSIVE …
#define HMM_DMIRROR_RELEASE …

/*
 * 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 { … };

enum { … };

#endif /* _LIB_TEST_HMM_UAPI_H */