xref: /xnu-11417.140.69/osfmk/mach/vm_reclaim_private.h (revision 43a90889846e00bfb5cf1d255cdc0a701a1e05a4)
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27  */
28 #pragma once
29 #if defined(__LP64__)
30 #include <mach/mach_types.h>
31 #include <mach/vm_reclaim.h>
32 #include <ptrcheck.h>
33 
34 /*
35  * This header exists for the internal implementation in libsyscall/xnu
36  * and for observability with debugging tools. It should _NOT_ be used by
37  * clients.
38  */
39 
40 #define VM_RECLAIM_MAX_BUFFER_SIZE (128ull << 20)
41 #define VM_RECLAIM_MAX_CAPACITY ((VM_RECLAIM_MAX_BUFFER_SIZE - \
42 	offsetof(struct mach_vm_reclaim_ring_s, entries)) / \
43 	sizeof(struct mach_vm_reclaim_entry_s))
44 
45 __BEGIN_DECLS
46 
47 typedef struct mach_vm_reclaim_indices_s {
48 	_Atomic mach_vm_reclaim_id_t head;
49 	_Atomic mach_vm_reclaim_id_t tail;
50 	_Atomic mach_vm_reclaim_id_t busy;
51 } *mach_vm_reclaim_indices_t;
52 
53 typedef struct mach_vm_reclaim_entry_s {
54 	mach_vm_address_t address;
55 	uint32_t size;
56 	mach_vm_reclaim_action_t behavior;
57 	uint8_t _unused[3];
58 } *mach_vm_reclaim_entry_t;
59 
60 /*
61  * Contains the data used for synchronization with the kernel. This structure
62  * should be page-aligned.
63  */
64 struct mach_vm_reclaim_ring_s {
65 	mach_vm_size_t va_in_buffer;
66 	mach_vm_size_t last_accounting_given_to_kernel;
67 	mach_vm_reclaim_count_t len;
68 	mach_vm_reclaim_count_t max_len;
69 	struct mach_vm_reclaim_indices_s indices;
70 	/*
71 	 * The ringbuffer entries themselves populate the remainder of this
72 	 * buffer's vm allocation.
73 	 * NB: the fields preceding `entries` must be aligned to a multiple of
74 	 * the entry size.
75 	 */
76 	struct mach_vm_reclaim_entry_s entries[] __counted_by(len);
77 };
78 
79 __END_DECLS
80 #endif /* __LP64__ */
81