xref: /haiku/src/system/kernel/arch/ppc/arch_thread.cpp (revision 3be9edf8da228afd9fec0390f408c964766122aa)
1 /*
2  * Copyright 2003-2007, Haiku Inc. All rights reserved.
3  * Distributed under the terms of the MIT License.
4  *
5  * Authors:
6  * 		Axel Dörfler <axeld@pinc-software.de>
7  * 		Ingo Weinhold <bonefish@cs.tu-berlin.de>
8  *
9  * Copyright 2001, Travis Geiselbrecht. All rights reserved.
10  * Distributed under the terms of the NewOS License.
11  */
12 
13 #include <arch_thread.h>
14 
15 #include <arch_cpu.h>
16 #include <arch/thread.h>
17 #include <boot/stage2.h>
18 #include <kernel.h>
19 #include <thread.h>
20 #include <vm_types.h>
21 //#include <arch/vm_translation_map.h>
22 
23 #include <string.h>
24 
25 // Valid initial arch_thread state. We just memcpy() it when initializing
26 // a new thread structure.
27 static struct arch_thread sInitialState;
28 
29 // Helper function for thread creation, defined in arch_asm.S.
30 extern "C" void ppc_kernel_thread_root();
31 
32 extern "C" void ppc_switch_stack_and_call(addr_t newKstack, void (*func)(void *),
33 	void *arg);
34 
35 
36 void
37 ppc_push_iframe(struct iframe_stack *stack, struct iframe *frame)
38 {
39 	ASSERT(stack->index < IFRAME_TRACE_DEPTH);
40 	stack->frames[stack->index++] = frame;
41 }
42 
43 
44 void
45 ppc_pop_iframe(struct iframe_stack *stack)
46 {
47 	ASSERT(stack->index > 0);
48 	stack->index--;
49 }
50 
51 
52 /**	Returns the current iframe structure of the running thread.
53  *	This function must only be called in a context where it's actually
54  *	sure that such iframe exists; ie. from syscalls, but usually not
55  *	from standard kernel threads.
56  */
57 static struct iframe *
58 ppc_get_current_iframe(void)
59 {
60 	struct thread *thread = thread_get_current_thread();
61 
62 	ASSERT(thread->arch_info.iframes.index >= 0);
63 	return thread->arch_info.iframes.frames[thread->arch_info.iframes.index - 1];
64 }
65 
66 
67 /** \brief Returns the current thread's topmost (i.e. most recent)
68  *  userland->kernel transition iframe (usually the first one, save for
69  *  interrupts in signal handlers).
70  *  \return The iframe, or \c NULL, if there is no such iframe (e.g. when
71  *          the thread is a kernel thread).
72  */
73 struct iframe *
74 ppc_get_user_iframe(void)
75 {
76 	struct thread *thread = thread_get_current_thread();
77 	int i;
78 
79 	for (i = thread->arch_info.iframes.index - 1; i >= 0; i--) {
80 		struct iframe *frame = thread->arch_info.iframes.frames[i];
81 		if (frame->srr1 & MSR_PRIVILEGE_LEVEL)
82 			return frame;
83 	}
84 
85 	return NULL;
86 }
87 
88 
89 // #pragma mark -
90 
91 
92 status_t
93 arch_thread_init(struct kernel_args *args)
94 {
95 	// Initialize the static initial arch_thread state (sInitialState).
96 	// Currently nothing to do, i.e. zero initialized is just fine.
97 
98 	return B_OK;
99 }
100 
101 
102 status_t
103 arch_team_init_team_struct(struct team *team, bool kernel)
104 {
105 	// Nothing to do. The structure is empty.
106 	return B_OK;
107 }
108 
109 
110 status_t
111 arch_thread_init_thread_struct(struct thread *thread)
112 {
113 	// set up an initial state (stack & fpu)
114 	memcpy(&thread->arch_info, &sInitialState, sizeof(struct arch_thread));
115 
116 	return B_OK;
117 }
118 
119 
120 status_t
121 arch_thread_init_kthread_stack(struct thread *t, int (*start_func)(void),
122 	void (*entry_func)(void), void (*exit_func)(void))
123 {
124 	addr_t *kstack = (addr_t *)t->kernel_stack_base;
125 	addr_t *kstackTop = (addr_t *)t->kernel_stack_top;
126 
127 	// clear the kernel stack
128 #ifdef DEBUG_KERNEL_STACKS
129 #	ifdef STACK_GROWS_DOWNWARDS
130 	memset((void *)((addr_t)kstack + KERNEL_STACK_GUARD_PAGES * B_PAGE_SIZE), 0,
131 		KERNEL_STACK_SIZE);
132 #	else
133 	memset(kstack, 0, KERNEL_STACK_SIZE);
134 #	endif
135 #else
136 	memset(kstack, 0, KERNEL_STACK_SIZE);
137 #endif
138 
139 	// space for frame pointer and return address, and stack frames must be
140 	// 16 byte aligned
141 	kstackTop -= 2;
142 	kstackTop = (addr_t*)((addr_t)kstackTop & ~0xf);
143 
144 	// LR, CR, r2, r13-r31, f13-f31, as pushed by ppc_context_switch()
145 	kstackTop -= 22 + 2 * 19;
146 
147 	// let LR point to ppc_kernel_thread_root()
148 	kstackTop[0] = (addr_t)&ppc_kernel_thread_root;
149 
150 	// the arguments of ppc_kernel_thread_root() are the functions to call,
151 	// provided in registers r13-r15
152 	kstackTop[3] = (addr_t)entry_func;
153 	kstackTop[4] = (addr_t)start_func;
154 	kstackTop[5] = (addr_t)exit_func;
155 
156 	// save this stack position
157 	t->arch_info.sp = (void *)kstackTop;
158 
159 	return B_OK;
160 }
161 
162 
163 status_t
164 arch_thread_init_tls(struct thread *thread)
165 {
166 	// TODO: Implement!
167 	return B_OK;
168 }
169 
170 
171 void
172 arch_thread_switch_kstack_and_call(struct thread *t, addr_t newKstack,
173 	void (*func)(void *), void *arg)
174 {
175 	ppc_switch_stack_and_call(newKstack, func, arg);
176 }
177 
178 
179 void
180 arch_thread_context_switch(struct thread *t_from, struct thread *t_to)
181 {
182     // set the new kernel stack in the EAR register.
183 	// this is used in the exception handler code to decide what kernel stack to
184 	// switch to if the exception had happened when the processor was in user mode
185 	asm("mtear  %0" :: "g"(t_to->kernel_stack_top - 8));
186 
187     // switch the asids if we need to
188 	if (t_to->team->address_space != NULL) {
189 		// the target thread has is user space
190 		if (t_from->team != t_to->team) {
191 			// switching to a new address space
192 			ppc_translation_map_change_asid(&t_to->team->address_space->translation_map);
193 		}
194 	}
195 
196 	ppc_context_switch(&t_from->arch_info.sp, t_to->arch_info.sp);
197 }
198 
199 
200 void
201 arch_thread_dump_info(void *info)
202 {
203 	struct arch_thread *at = (struct arch_thread *)info;
204 
205 	dprintf("\tsp: %p\n", at->sp);
206 }
207 
208 
209 status_t
210 arch_thread_enter_userspace(struct thread *thread, addr_t entry, void *arg1, void *arg2)
211 {
212 	panic("arch_thread_enter_uspace(): not yet implemented\n");
213 	return B_ERROR;
214 }
215 
216 
217 bool
218 arch_on_signal_stack(struct thread *thread)
219 {
220 	return false;
221 }
222 
223 
224 status_t
225 arch_setup_signal_frame(struct thread *thread, struct sigaction *sa, int sig, int sigMask)
226 {
227 	return B_ERROR;
228 }
229 
230 
231 int64
232 arch_restore_signal_frame(void)
233 {
234 	return 0;
235 }
236 
237 
238 
239 /**	Saves everything needed to restore the frame in the child fork in the
240  *	arch_fork_arg structure to be passed to arch_restore_fork_frame().
241  *	Also makes sure to return the right value.
242  */
243 
244 void
245 arch_store_fork_frame(struct arch_fork_arg *arg)
246 {
247 }
248 
249 
250 /** Restores the frame from a forked team as specified by the provided
251  *	arch_fork_arg structure.
252  *	Needs to be called from within the child team, ie. instead of
253  *	arch_thread_enter_uspace() as thread "starter".
254  *	This function does not return to the caller, but will enter userland
255  *	in the child team at the same position where the parent team left of.
256  */
257 
258 void
259 arch_restore_fork_frame(struct arch_fork_arg *arg)
260 {
261 }
262 
263