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-rw-r--r--lib/test_hmm_uapi.h59
1 files changed, 59 insertions, 0 deletions
diff --git a/lib/test_hmm_uapi.h b/lib/test_hmm_uapi.h
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index 000000000000..67b3b2e6ff5d
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+++ b/lib/test_hmm_uapi.h
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+/* 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 _IOWR('H', 0x02, struct hmm_dmirror_cmd)
+#define HMM_DMIRROR_SNAPSHOT _IOWR('H', 0x03, struct hmm_dmirror_cmd)
+
+/*
+ * 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_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
+ */
+enum {
+ HMM_DMIRROR_PROT_ERROR = 0xFF,
+ HMM_DMIRROR_PROT_NONE = 0x00,
+ HMM_DMIRROR_PROT_READ = 0x01,
+ HMM_DMIRROR_PROT_WRITE = 0x02,
+ HMM_DMIRROR_PROT_ZERO = 0x10,
+ HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL = 0x20,
+ HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE = 0x30,
+};
+
+#endif /* _LIB_TEST_HMM_UAPI_H */