1/*
2 * Copyright 2021-2022 Haiku, Inc. All rights reserved.
3 * Released under the terms of the MIT License.
4 *
5 * Copyright 2008, Dustin Howett, dustin.howett@gmail.com. All rights reserved.
6 * Copyright 2004-2010, Axel D��rfler, axeld@pinc-software.de.
7 * Distributed under the terms of the MIT License.
8 *
9 * Copyright 2001, Travis Geiselbrecht. All rights reserved.
10 * Distributed under the terms of the NewOS License.
11 */
12
13
14#include "arch_smp.h"
15
16#include <boot/stage2.h>
17
18
19//#define TRACE_SMP
20#ifdef TRACE_SMP
21#	define TRACE(x...) dprintf(x)
22#else
23#	define TRACE(x...) ;
24#endif
25
26
27extern "C" void long_smp_trampoline(void);
28extern "C" void long_smp_trampoline_args(void);
29extern "C" void long_smp_trampoline_end(void);
30extern "C" uint64 gLongGDTR;
31
32struct gdtr {
33    uint16 limit;
34    uint32 base;
35    unsigned char null[8];
36    unsigned char code[8];
37    unsigned char data[8];
38} __attribute__((packed));
39
40// Arguments passed to the SMP trampoline.
41struct long_trampoline_args {
42	uint32 trampoline;        // Trampoline address
43	uint32 gdt32;             // 32-bit GDTR
44	uint32 pml4;              // 64-bit PML4
45	uint32 gdt64;             // 64-bit GDTR
46	uint64 kernel_entry;      // Kernel entry point
47	uint64 kernel_args;       // Kernel arguments
48	uint64 current_cpu;       // CPU number
49	uint64 stack_top;         // Kernel stack
50	volatile uint64 sentinel; // Sentinel, AP sets to 0 when finished
51
52	// smp_boot_other_cpus puts the GDTR here.
53	struct gdtr gdtr;
54};
55
56
57void
58copy_trampoline_code(uint64 trampolineCode, uint64 trampolineStack)
59{
60	TRACE("copying the trampoline code to %p from %p\n", (char*)trampolineCode, (const void*)&long_smp_trampoline);
61	TRACE("size of trampoline code = %" PRIu64 " bytes\n", (uint64)&long_smp_trampoline_end - (uint64)&long_smp_trampoline);
62	memcpy((char *)trampolineCode, (const void*)&long_smp_trampoline,
63		(uint64)&long_smp_trampoline_end - (uint64)&long_smp_trampoline);
64}
65
66
67void
68prepare_trampoline_args(uint64 trampolineCode, uint64 trampolineStack,
69	uint32 pagedir, uint64 kernelEntry, addr_t virtKernelArgs,
70	uint32 currentCpu)
71{
72	long_trampoline_args* args = (long_trampoline_args *)trampolineStack;
73	args->trampoline = trampolineCode;
74
75	args->gdt32 = (uint64) &args->gdtr;
76	args->gdtr.limit = 23;
77	args->gdtr.base = (uint32)(uint64)args->gdtr.null;
78	#define COPY_ARRAY(A, X0, X1, X2, X3, X4, X5, X6, X7) \
79		{ A[0] = X0; A[1] = X1; A[2] = X2; A[3] = X3; A[4] = X4; A[5] = X5; A[6] = X6; A[7] = X7; }
80	COPY_ARRAY(args->gdtr.null, 0, 0, 0, 0, 0, 0, 0, 0);
81	COPY_ARRAY(args->gdtr.code, 0xff, 0xff, 0, 0, 0, 0x9a, 0xcf, 0);
82	COPY_ARRAY(args->gdtr.data, 0xff, 0xff, 0, 0, 0, 0x92, 0xcf, 0);
83	#undef COPY_ARRAY
84	args->gdt64 = (uint32_t)(uint64_t)&gLongGDTR;
85
86	args->pml4 = pagedir;
87	args->kernel_entry = kernelEntry;
88	args->kernel_args = virtKernelArgs;
89	args->current_cpu = currentCpu;
90	args->stack_top = gKernelArgs.cpu_kstack[currentCpu].start
91		+ gKernelArgs.cpu_kstack[currentCpu].size;
92	args->sentinel = 1;
93
94	// put the args in the right place
95	uint32 * args_ptr =
96		(uint32 *)(trampolineCode + (uint64)long_smp_trampoline_args - (uint64)long_smp_trampoline);
97	*args_ptr = (uint32)trampolineStack;
98}
99
100
101uint32
102get_sentinel(uint64 trampolineStack)
103{
104	long_trampoline_args* args = (long_trampoline_args *)trampolineStack;
105	return args->sentinel;
106}
107