1/* Copyright 2019, Adrien Destugues, pulkomandy@pulkomandy.tk
2 * Distributed under the terms of the MIT License.
3 */
4
5
6#include <string.h>
7
8#include <arch_cpu.h>
9#include <arch_debug.h>
10#include <arch/thread.h>
11#include <boot/stage2.h>
12#include <commpage.h>
13#include <kernel.h>
14#include <thread.h>
15#include <team.h>
16#include <vm/vm_types.h>
17#include <vm/VMAddressSpace.h>
18
19#include "RISCV64VMTranslationMap.h"
20
21
22extern "C" void SVecU();
23
24
25status_t
26arch_thread_init(struct kernel_args *args)
27{
28	// Initialize the static initial arch_thread state (sInitialState).
29	// Currently nothing to do, i.e. zero initialized is just fine.
30
31	return B_OK;
32}
33
34
35status_t
36arch_team_init_team_struct(Team *team, bool kernel)
37{
38	// Nothing to do. The structure is empty.
39	return B_OK;
40}
41
42
43status_t
44arch_thread_init_thread_struct(Thread *thread)
45{
46	return B_OK;
47}
48
49
50void
51arch_thread_init_kthread_stack(Thread* thread, void* _stack, void* _stackTop,
52	void (*function)(void*), const void* data)
53{
54	memset(&thread->arch_info.context, 0, sizeof(arch_context));
55	thread->arch_info.context.sp = (addr_t)_stackTop;
56	thread->arch_info.context.s[0] = 0; // fp
57	thread->arch_info.context.s[1] = (addr_t)function;
58	thread->arch_info.context.s[2] = (addr_t)data;
59	thread->arch_info.context.ra = (addr_t)arch_thread_entry;
60
61	memset(&thread->arch_info.fpuContext, 0, sizeof(fpu_context));
62}
63
64
65status_t
66arch_thread_init_tls(Thread *thread)
67{
68	thread->user_local_storage =
69		thread->user_stack_base + thread->user_stack_size;
70	return B_OK;
71}
72
73
74void
75arch_thread_context_switch(Thread *from, Thread *to)
76{
77	/*
78	dprintf("arch_thread_context_switch(%p(%s), %p(%s))\n", from, from->name,
79		to, to->name);
80	*/
81
82	auto fromMap = (RISCV64VMTranslationMap*)from->team->address_space->TranslationMap();
83	auto toMap = (RISCV64VMTranslationMap*)to->team->address_space->TranslationMap();
84
85	int cpu = to->cpu->cpu_num;
86	toMap->ActiveOnCpus().SetBitAtomic(cpu);
87	fromMap->ActiveOnCpus().ClearBitAtomic(cpu);
88
89	// TODO: save/restore FPU only if needed
90	save_fpu(&from->arch_info.fpuContext);
91	restore_fpu(&to->arch_info.fpuContext);
92
93	SetSatp(toMap->Satp());
94	FlushTlbAllAsid(0);
95
96	arch_context_switch(&from->arch_info.context, &to->arch_info.context);
97}
98
99
100void
101arch_thread_dump_info(void *info)
102{
103}
104
105
106status_t
107arch_thread_enter_userspace(Thread *thread, addr_t entry, void *arg1,
108	void *arg2)
109{
110	//dprintf("arch_thread_enter_uspace(%" B_PRId32 "(%s))\n", thread->id, thread->name);
111
112	addr_t commpageAdr = (addr_t)thread->team->commpage_address;
113	addr_t threadExitAddr;
114	ASSERT(user_memcpy(&threadExitAddr,
115		&((addr_t*)commpageAdr)[COMMPAGE_ENTRY_RISCV64_THREAD_EXIT],
116		sizeof(threadExitAddr)) >= B_OK);
117	threadExitAddr += commpageAdr;
118
119	disable_interrupts();
120
121	arch_stack* stackHeader = (arch_stack*)thread->kernel_stack_top - 1;
122	stackHeader->thread = thread;
123
124	iframe frame;
125	memset(&frame, 0, sizeof(frame));
126
127	SstatusReg status{.val = Sstatus()};
128	status.pie = (1 << modeS); // enable interrupts when enter userspace
129	status.spp = modeU;
130
131	frame.status = status.val;
132	frame.epc = entry;
133	frame.a0 = (addr_t)arg1;
134	frame.a1 = (addr_t)arg2;
135	frame.ra = threadExitAddr;
136	frame.sp = thread->user_stack_base + thread->user_stack_size;
137	frame.tp = thread->user_local_storage;
138
139	arch_load_user_iframe(stackHeader, &frame);
140
141	// never return
142	return B_ERROR;
143}
144
145
146bool
147arch_on_signal_stack(Thread *thread)
148{
149	struct iframe* frame = thread->arch_info.userFrame;
150	if (frame == NULL) {
151		panic("arch_on_signal_stack(): No user iframe!");
152		return false;
153	}
154
155	return frame->sp >= thread->signal_stack_base
156		&& frame->sp < thread->signal_stack_base
157			+ thread->signal_stack_size;
158}
159
160
161static uint8*
162get_signal_stack(Thread* thread, struct iframe* frame,
163	struct sigaction* action, size_t spaceNeeded)
164{
165	// use the alternate signal stack if we should and can
166	if (
167		thread->signal_stack_enabled &&
168		(action->sa_flags & SA_ONSTACK) != 0 && (
169			frame->sp < thread->signal_stack_base ||
170			frame->sp >= thread->signal_stack_base + thread->signal_stack_size
171		)
172	) {
173		addr_t stackTop = thread->signal_stack_base
174			+ thread->signal_stack_size;
175		return (uint8*)ROUNDDOWN(stackTop - spaceNeeded, 16);
176	}
177	return (uint8*)ROUNDDOWN(frame->sp - spaceNeeded, 16);
178}
179
180
181status_t
182arch_setup_signal_frame(Thread *thread, struct sigaction *sa,
183	struct signal_frame_data *signalFrameData)
184{
185	// dprintf("%s(%" B_PRId32 "(%s))\n", __func__, thread->id, thread->name);
186	iframe* frame = thread->arch_info.userFrame;
187
188	// fill signal context
189	signalFrameData->context.uc_mcontext.x[ 0] = frame->ra;
190	signalFrameData->context.uc_mcontext.x[ 1] = frame->sp;
191	signalFrameData->context.uc_mcontext.x[ 2] = frame->gp;
192	signalFrameData->context.uc_mcontext.x[ 3] = frame->tp;
193	signalFrameData->context.uc_mcontext.x[ 4] = frame->t0;
194	signalFrameData->context.uc_mcontext.x[ 5] = frame->t1;
195	signalFrameData->context.uc_mcontext.x[ 6] = frame->t2;
196	signalFrameData->context.uc_mcontext.x[ 7] = frame->fp;
197	signalFrameData->context.uc_mcontext.x[ 8] = frame->s1;
198	signalFrameData->context.uc_mcontext.x[ 9] = frame->a0;
199	signalFrameData->context.uc_mcontext.x[10] = frame->a1;
200	signalFrameData->context.uc_mcontext.x[11] = frame->a2;
201	signalFrameData->context.uc_mcontext.x[12] = frame->a3;
202	signalFrameData->context.uc_mcontext.x[13] = frame->a4;
203	signalFrameData->context.uc_mcontext.x[14] = frame->a5;
204	signalFrameData->context.uc_mcontext.x[15] = frame->a6;
205	signalFrameData->context.uc_mcontext.x[16] = frame->a7;
206	signalFrameData->context.uc_mcontext.x[17] = frame->s2;
207	signalFrameData->context.uc_mcontext.x[18] = frame->s3;
208	signalFrameData->context.uc_mcontext.x[19] = frame->s4;
209	signalFrameData->context.uc_mcontext.x[20] = frame->s5;
210	signalFrameData->context.uc_mcontext.x[21] = frame->s6;
211	signalFrameData->context.uc_mcontext.x[22] = frame->s7;
212	signalFrameData->context.uc_mcontext.x[23] = frame->s8;
213	signalFrameData->context.uc_mcontext.x[24] = frame->s9;
214	signalFrameData->context.uc_mcontext.x[25] = frame->s10;
215	signalFrameData->context.uc_mcontext.x[26] = frame->s11;
216	signalFrameData->context.uc_mcontext.x[27] = frame->t3;
217	signalFrameData->context.uc_mcontext.x[28] = frame->t4;
218	signalFrameData->context.uc_mcontext.x[29] = frame->t5;
219	signalFrameData->context.uc_mcontext.x[30] = frame->t6;
220	signalFrameData->context.uc_mcontext.pc = frame->epc;
221	// TODO: don't assume that kernel code don't use FPU
222	save_fpu((fpu_context*)&signalFrameData->context.uc_mcontext.f[0]);
223	// end of fill signal context
224
225	signal_get_user_stack(frame->sp, &signalFrameData->context.uc_stack);
226/*
227	dprintf("  thread->signal_stack_enabled: %d\n",
228		thread->signal_stack_enabled);
229	if (thread->signal_stack_enabled) {
230		dprintf("  signal stack: 0x%" B_PRIxADDR " - 0x%" B_PRIxADDR "\n",
231			thread->signal_stack_base,
232			thread->signal_stack_base + thread->signal_stack_size
233		);
234	}
235*/
236	signalFrameData->syscall_restart_return_value = thread->arch_info.oldA0;
237
238	uint8* userStack = get_signal_stack(thread, frame, sa,
239		sizeof(*signalFrameData));
240	// dprintf("  user stack: 0x%" B_PRIxADDR "\n", (addr_t)userStack);
241	status_t res = user_memcpy(userStack, signalFrameData,
242		sizeof(*signalFrameData));
243	if (res < B_OK)
244		return res;
245
246	addr_t commpageAdr = (addr_t)thread->team->commpage_address;
247	// dprintf("  commpageAdr: 0x%" B_PRIxADDR "\n", commpageAdr);
248	addr_t signalHandlerAddr;
249	ASSERT(user_memcpy(&signalHandlerAddr,
250		&((addr_t*)commpageAdr)[COMMPAGE_ENTRY_RISCV64_SIGNAL_HANDLER],
251		sizeof(signalHandlerAddr)) >= B_OK);
252	signalHandlerAddr += commpageAdr;
253
254	frame->ra = frame->epc;
255	frame->sp = (addr_t)userStack;
256	frame->epc = signalHandlerAddr;
257	frame->a0 = frame->sp;
258
259	// WriteTrapInfo();
260
261	return B_OK;
262}
263
264
265int64
266arch_restore_signal_frame(struct signal_frame_data* signalFrameData)
267{
268	// dprintf("arch_restore_signal_frame()\n");
269	iframe* frame = thread_get_current_thread()->arch_info.userFrame;
270
271	thread_get_current_thread()->arch_info.oldA0
272		= signalFrameData->syscall_restart_return_value;
273
274	frame->ra  = signalFrameData->context.uc_mcontext.x[ 0];
275	frame->sp  = signalFrameData->context.uc_mcontext.x[ 1];
276	frame->gp  = signalFrameData->context.uc_mcontext.x[ 2];
277	frame->tp  = signalFrameData->context.uc_mcontext.x[ 3];
278	frame->t0  = signalFrameData->context.uc_mcontext.x[ 4];
279	frame->t1  = signalFrameData->context.uc_mcontext.x[ 5];
280	frame->t2  = signalFrameData->context.uc_mcontext.x[ 6];
281	frame->fp  = signalFrameData->context.uc_mcontext.x[ 7];
282	frame->s1  = signalFrameData->context.uc_mcontext.x[ 8];
283	frame->a0  = signalFrameData->context.uc_mcontext.x[ 9];
284	frame->a1  = signalFrameData->context.uc_mcontext.x[10];
285	frame->a2  = signalFrameData->context.uc_mcontext.x[11];
286	frame->a3  = signalFrameData->context.uc_mcontext.x[12];
287	frame->a4  = signalFrameData->context.uc_mcontext.x[13];
288	frame->a5  = signalFrameData->context.uc_mcontext.x[14];
289	frame->a6  = signalFrameData->context.uc_mcontext.x[15];
290	frame->a7  = signalFrameData->context.uc_mcontext.x[16];
291	frame->s2  = signalFrameData->context.uc_mcontext.x[17];
292	frame->s3  = signalFrameData->context.uc_mcontext.x[18];
293	frame->s4  = signalFrameData->context.uc_mcontext.x[19];
294	frame->s5  = signalFrameData->context.uc_mcontext.x[20];
295	frame->s6  = signalFrameData->context.uc_mcontext.x[21];
296	frame->s7  = signalFrameData->context.uc_mcontext.x[22];
297	frame->s8  = signalFrameData->context.uc_mcontext.x[23];
298	frame->s9  = signalFrameData->context.uc_mcontext.x[24];
299	frame->s10 = signalFrameData->context.uc_mcontext.x[25];
300	frame->s11 = signalFrameData->context.uc_mcontext.x[26];
301	frame->t3  = signalFrameData->context.uc_mcontext.x[27];
302	frame->t4  = signalFrameData->context.uc_mcontext.x[28];
303	frame->t5  = signalFrameData->context.uc_mcontext.x[29];
304	frame->t6  = signalFrameData->context.uc_mcontext.x[30];
305	frame->epc = signalFrameData->context.uc_mcontext.pc;
306	restore_fpu((fpu_context*)&signalFrameData->context.uc_mcontext.f[0]);
307
308	return frame->a0;
309}
310
311
312/**	Saves everything needed to restore the frame in the child fork in the
313 *	arch_fork_arg structure to be passed to arch_restore_fork_frame().
314 *	Also makes sure to return the right value.
315 */
316
317void
318arch_store_fork_frame(struct arch_fork_arg *arg)
319{
320/*
321	dprintf("arch_store_fork_frame()\n");
322	dprintf("  arg: %p\n", arg);
323	dprintf("  userFrame: %p\n",
324		thread_get_current_thread()->arch_info.userFrame);
325*/
326	memcpy(&arg->frame, thread_get_current_thread()->arch_info.userFrame,
327		sizeof(iframe));
328	arg->frame.a0 = 0; // fork return value
329}
330
331
332/** Restores the frame from a forked team as specified by the provided
333 *	arch_fork_arg structure.
334 *	Needs to be called from within the child team, ie. instead of
335 *	arch_thread_enter_uspace() as thread "starter".
336 *	This function does not return to the caller, but will enter userland
337 *	in the child team at the same position where the parent team left of.
338 */
339
340void
341arch_restore_fork_frame(struct arch_fork_arg *arg)
342{
343	//dprintf("arch_restore_fork_frame(%p)\n", arg);
344	//dprintf("  thread: %" B_PRId32 "(%s))\n", thread_get_current_thread()->id,
345	//	thread_get_current_thread()->name);
346	//dprintf("  kernel SP: %#" B_PRIxADDR "\n", thread_get_current_thread()->kernel_stack_top);
347	//dprintf("  user PC: "); WritePC(arg->frame.epc); dprintf("\n");
348
349	disable_interrupts();
350
351	arch_stack* stackHeader = (arch_stack*)thread_get_current_thread()->kernel_stack_top - 1;
352	stackHeader->thread = thread_get_current_thread();
353	SstatusReg status{.val = Sstatus()};
354	status.pie = (1 << modeS); // enable interrupts when enter userspace
355	status.spp = modeU;
356	arg->frame.status = status.val;
357	arch_load_user_iframe(stackHeader, &arg->frame);
358}
359