1 /*
2 * Copyright (c) 2014 Wind River Systems, Inc.
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 /**
8 * @file
9 * @brief New thread creation for ARCv2
10 *
11 * Core thread related primitives for the ARCv2 processor architecture.
12 */
13
14 #include <zephyr/kernel.h>
15 #include <ksched.h>
16 #include <offsets_short.h>
17
18 #ifdef CONFIG_USERSPACE
19 #include <zephyr/arch/arc/v2/mpu/arc_core_mpu.h>
20 #endif
21
22 #if defined(CONFIG_ARC_VPX_COOPERATIVE_SHARING) || defined(CONFIG_DSP_SHARING)
23 #include <zephyr/arch/arc/v2/dsp/arc_dsp.h>
24 static struct k_spinlock lock;
25 #endif
26
27 #if defined(CONFIG_ARC_VPX_COOPERATIVE_SHARING)
28 static struct k_sem vpx_sem[CONFIG_MP_MAX_NUM_CPUS];
29 #endif
30
31 /* initial stack frame */
32 struct init_stack_frame {
33 uintptr_t pc;
34 #ifdef CONFIG_ARC_HAS_SECURE
35 uint32_t sec_stat;
36 #endif
37 uintptr_t status32;
38 uintptr_t r3;
39 uintptr_t r2;
40 uintptr_t r1;
41 uintptr_t r0;
42 };
43
44 #ifdef CONFIG_USERSPACE
45 struct user_init_stack_frame {
46 struct init_stack_frame iframe;
47 uint32_t user_sp;
48 };
49
is_user(struct k_thread * thread)50 static bool is_user(struct k_thread *thread)
51 {
52 return (thread->base.user_options & K_USER) != 0;
53 }
54 #endif
55
56 /* Set all stack-related architecture variables for the provided thread */
setup_stack_vars(struct k_thread * thread)57 static void setup_stack_vars(struct k_thread *thread)
58 {
59 #ifdef CONFIG_USERSPACE
60 if (is_user(thread)) {
61 #ifdef CONFIG_GEN_PRIV_STACKS
62 thread->arch.priv_stack_start =
63 (uint32_t)z_priv_stack_find(thread->stack_obj);
64 #else
65 thread->arch.priv_stack_start = (uint32_t)(thread->stack_obj);
66 #endif /* CONFIG_GEN_PRIV_STACKS */
67 thread->arch.priv_stack_start += Z_ARC_STACK_GUARD_SIZE;
68 } else {
69 thread->arch.priv_stack_start = 0;
70 }
71 #endif /* CONFIG_USERSPACE */
72
73 #ifdef CONFIG_ARC_STACK_CHECKING
74 #ifdef CONFIG_USERSPACE
75 if (is_user(thread)) {
76 thread->arch.k_stack_top = thread->arch.priv_stack_start;
77 thread->arch.k_stack_base = (thread->arch.priv_stack_start +
78 CONFIG_PRIVILEGED_STACK_SIZE);
79 thread->arch.u_stack_top = thread->stack_info.start;
80 thread->arch.u_stack_base = (thread->stack_info.start +
81 thread->stack_info.size);
82 } else
83 #endif /* CONFIG_USERSPACE */
84 {
85 thread->arch.k_stack_top = (uint32_t)thread->stack_info.start;
86 thread->arch.k_stack_base = (uint32_t)(thread->stack_info.start +
87 thread->stack_info.size);
88 #ifdef CONFIG_USERSPACE
89 thread->arch.u_stack_top = 0;
90 thread->arch.u_stack_base = 0;
91 #endif /* CONFIG_USERSPACE */
92 }
93 #endif /* CONFIG_ARC_STACK_CHECKING */
94 }
95
96 /* Get the initial stack frame pointer from the thread's stack buffer. */
get_iframe(struct k_thread * thread,char * stack_ptr)97 static struct init_stack_frame *get_iframe(struct k_thread *thread,
98 char *stack_ptr)
99 {
100 #ifdef CONFIG_USERSPACE
101 if (is_user(thread)) {
102 /* Initial stack frame for a user thread is slightly larger;
103 * we land in z_user_thread_entry_wrapper on the privilege
104 * stack, and pop off an additional value for the user
105 * stack pointer.
106 */
107 struct user_init_stack_frame *uframe;
108
109 uframe = Z_STACK_PTR_TO_FRAME(struct user_init_stack_frame,
110 thread->arch.priv_stack_start +
111 CONFIG_PRIVILEGED_STACK_SIZE);
112 uframe->user_sp = (uint32_t)stack_ptr;
113 return &uframe->iframe;
114 }
115 #endif
116 return Z_STACK_PTR_TO_FRAME(struct init_stack_frame, stack_ptr);
117 }
118
119 /*
120 * Pre-populate values in the registers inside _callee_saved_stack struct
121 * so these registers have pre-defined values when new thread begins
122 * execution. For example, setting up the thread pointer for thread local
123 * storage here so the thread starts with thread pointer already set up.
124 */
arch_setup_callee_saved_regs(struct k_thread * thread,uintptr_t stack_ptr)125 static inline void arch_setup_callee_saved_regs(struct k_thread *thread,
126 uintptr_t stack_ptr)
127 {
128 _callee_saved_stack_t *regs = UINT_TO_POINTER(stack_ptr);
129
130 ARG_UNUSED(regs);
131
132 /* GCC uses tls pointer cached in register, MWDT just call for _mwget_tls */
133 #if defined(CONFIG_THREAD_LOCAL_STORAGE) && !defined(__CCAC__)
134 #ifdef CONFIG_ISA_ARCV2
135 #if __ARC_TLS_REGNO__ <= 0
136 #error Compiler not configured for thread local storage
137 #endif
138 #define TLSREG _CONCAT(r, __ARC_TLS_REGNO__)
139 /* __ARC_TLS_REGNO__ is used for thread pointer for ARCv2 */
140 regs->TLSREG = thread->tls;
141 #else
142 /* R30 is used for thread pointer for ARCv3 */
143 regs->r30 = thread->tls;
144 #endif /* CONFIG_ISA_ARCV2 */
145 #endif
146 }
147
148 /*
149 * The initial context is a basic stack frame that contains arguments for
150 * z_thread_entry() return address, that points at z_thread_entry()
151 * and status register.
152 */
arch_new_thread(struct k_thread * thread,k_thread_stack_t * stack,char * stack_ptr,k_thread_entry_t entry,void * p1,void * p2,void * p3)153 void arch_new_thread(struct k_thread *thread, k_thread_stack_t *stack,
154 char *stack_ptr, k_thread_entry_t entry,
155 void *p1, void *p2, void *p3)
156 {
157 struct init_stack_frame *iframe;
158
159 setup_stack_vars(thread);
160
161 /* Set up initial stack frame */
162 iframe = get_iframe(thread, stack_ptr);
163
164 #ifdef CONFIG_USERSPACE
165 /* enable US bit, US is read as zero in user mode. This will allow user
166 * mode sleep instructions, and it enables a form of denial-of-service
167 * attack by putting the processor in sleep mode, but since interrupt
168 * level/mask can't be set from user space that's not worse than
169 * executing a loop without yielding.
170 */
171 iframe->status32 = _ARC_V2_STATUS32_US | _ARC_V2_STATUS32_DZ;
172 if (is_user(thread)) {
173 iframe->pc = (uint32_t)z_user_thread_entry_wrapper;
174 } else {
175 iframe->pc = (uint32_t)z_thread_entry_wrapper;
176 }
177 #else
178 iframe->status32 = _ARC_V2_STATUS32_DZ;
179 iframe->pc = ((uintptr_t)z_thread_entry_wrapper);
180 #endif /* CONFIG_USERSPACE */
181 #ifdef CONFIG_ARC_SECURE_FIRMWARE
182 iframe->sec_stat = z_arc_v2_aux_reg_read(_ARC_V2_SEC_STAT);
183 #endif
184 iframe->r0 = (uintptr_t)entry;
185 iframe->r1 = (uintptr_t)p1;
186 iframe->r2 = (uintptr_t)p2;
187 iframe->r3 = (uintptr_t)p3;
188
189 #ifdef CONFIG_ARC_STACK_CHECKING
190 #ifdef CONFIG_ARC_SECURE_FIRMWARE
191 iframe->sec_stat |= _ARC_V2_SEC_STAT_SSC;
192 #else
193 iframe->status32 |= _ARC_V2_STATUS32_SC;
194 #endif /* CONFIG_ARC_SECURE_FIRMWARE */
195 #endif /* CONFIG_ARC_STACK_CHECKING */
196 #ifdef CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS
197 iframe->status32 |= _ARC_V2_STATUS32_AD;
198 #endif
199 /* Set required thread members */
200 thread->switch_handle = thread;
201 thread->arch.relinquish_cause = _CAUSE_COOP;
202 thread->callee_saved.sp =
203 (uintptr_t)iframe - ___callee_saved_stack_t_SIZEOF;
204
205 arch_setup_callee_saved_regs(thread, thread->callee_saved.sp);
206
207 /* initial values in all other regs/k_thread entries are irrelevant */
208 }
209
210 #ifdef CONFIG_MULTITHREADING
z_arch_get_next_switch_handle(struct k_thread ** old_thread)211 void *z_arch_get_next_switch_handle(struct k_thread **old_thread)
212 {
213 *old_thread = arch_current_thread();
214
215 return z_get_next_switch_handle(NULL);
216 }
217 #else
z_arch_get_next_switch_handle(struct k_thread ** old_thread)218 void *z_arch_get_next_switch_handle(struct k_thread **old_thread)
219 {
220 ARG_UNUSED(old_thread);
221
222 return NULL;
223 }
224 #endif
225
226 #ifdef CONFIG_USERSPACE
arch_user_mode_enter(k_thread_entry_t user_entry,void * p1,void * p2,void * p3)227 FUNC_NORETURN void arch_user_mode_enter(k_thread_entry_t user_entry,
228 void *p1, void *p2, void *p3)
229 {
230 setup_stack_vars(arch_current_thread());
231
232 /* possible optimizaiton: no need to load mem domain anymore */
233 /* need to lock cpu here ? */
234 configure_mpu_thread(arch_current_thread());
235
236 z_arc_userspace_enter(user_entry, p1, p2, p3,
237 (uint32_t)arch_current_thread()->stack_info.start,
238 (arch_current_thread()->stack_info.size -
239 arch_current_thread()->stack_info.delta), arch_current_thread());
240 CODE_UNREACHABLE;
241 }
242 #endif
243
244 #if defined(CONFIG_FPU) && defined(CONFIG_FPU_SHARING)
arch_float_disable(struct k_thread * thread)245 int arch_float_disable(struct k_thread *thread)
246 {
247 unsigned int key;
248
249 /* Ensure a preemptive context switch does not occur */
250
251 key = irq_lock();
252
253 /* Disable all floating point capabilities for the thread */
254 thread->base.user_options &= ~K_FP_REGS;
255
256 irq_unlock(key);
257
258 return 0;
259 }
260
261
arch_float_enable(struct k_thread * thread,unsigned int options)262 int arch_float_enable(struct k_thread *thread, unsigned int options)
263 {
264 unsigned int key;
265
266 /* Ensure a preemptive context switch does not occur */
267
268 key = irq_lock();
269
270 /* Enable all floating point capabilities for the thread */
271 thread->base.user_options |= K_FP_REGS;
272
273 irq_unlock(key);
274
275 return 0;
276 }
277 #endif /* CONFIG_FPU && CONFIG_FPU_SHARING */
278
279 #if !defined(CONFIG_MULTITHREADING)
280
281 K_KERNEL_STACK_ARRAY_DECLARE(z_interrupt_stacks, CONFIG_MP_MAX_NUM_CPUS, CONFIG_ISR_STACK_SIZE);
282 K_THREAD_STACK_DECLARE(z_main_stack, CONFIG_MAIN_STACK_SIZE);
283
284 extern void z_main_no_multithreading_entry_wrapper(void *p1, void *p2, void *p3,
285 void *main_stack, void *main_entry);
286
z_arc_switch_to_main_no_multithreading(k_thread_entry_t main_entry,void * p1,void * p2,void * p3)287 FUNC_NORETURN void z_arc_switch_to_main_no_multithreading(k_thread_entry_t main_entry,
288 void *p1, void *p2, void *p3)
289 {
290 _kernel.cpus[0].id = 0;
291 _kernel.cpus[0].irq_stack = (K_KERNEL_STACK_BUFFER(z_interrupt_stacks[0]) +
292 K_KERNEL_STACK_SIZEOF(z_interrupt_stacks[0]));
293
294 void *main_stack = (K_THREAD_STACK_BUFFER(z_main_stack) +
295 K_THREAD_STACK_SIZEOF(z_main_stack));
296
297 arch_irq_unlock(_ARC_V2_INIT_IRQ_LOCK_KEY);
298
299 z_main_no_multithreading_entry_wrapper(p1, p2, p3, main_stack, main_entry);
300
301 CODE_UNREACHABLE; /* LCOV_EXCL_LINE */
302 }
303 #endif /* !CONFIG_MULTITHREADING */
304
305 #if defined(CONFIG_ARC_DSP) && defined(CONFIG_DSP_SHARING)
arc_dsp_disable(struct k_thread * thread,unsigned int options)306 void arc_dsp_disable(struct k_thread *thread, unsigned int options)
307 {
308 /* Ensure a preemptive context switch does not occur */
309 k_spinlock_key_t key = k_spin_lock(&lock);
310
311 /* Disable DSP or AGU capabilities for the thread */
312 thread->base.user_options &= ~(uint8_t)options;
313
314 k_spin_unlock(&lock, key);
315 }
316
arc_dsp_enable(struct k_thread * thread,unsigned int options)317 void arc_dsp_enable(struct k_thread *thread, unsigned int options)
318 {
319 /* Ensure a preemptive context switch does not occur */
320 k_spinlock_key_t key = k_spin_lock(&lock);
321
322 /* Enable dsp or agu capabilities for the thread */
323 thread->base.user_options |= (uint8_t)options;
324
325 k_spin_unlock(&lock, key);
326 }
327 #endif /* CONFIG_ARC_DSP && CONFIG_DSP_SHARING */
328
329 #if defined(CONFIG_ARC_VPX_COOPERATIVE_SHARING)
arc_vpx_lock(k_timeout_t timeout)330 int arc_vpx_lock(k_timeout_t timeout)
331 {
332 k_spinlock_key_t key;
333 unsigned int id;
334
335 key = k_spin_lock(&lock);
336
337 id = _current_cpu->id;
338 #if (CONFIG_MP_MAX_NUM_CPUS > 1) && defined(CONFIG_SCHED_CPU_MASK)
339 __ASSERT(!arch_is_in_isr() && (arch_current_thread()->base.cpu_mask == BIT(id)), "");
340 #endif
341 k_spin_unlock(&lock, key);
342
343 /*
344 * It is assumed that the thread is (still) pinned to
345 * the same CPU identified by <id>.
346 */
347
348 return k_sem_take(&vpx_sem[id], timeout);
349 }
350
arc_vpx_unlock(void)351 void arc_vpx_unlock(void)
352 {
353 k_spinlock_key_t key;
354 unsigned int id;
355
356 key = k_spin_lock(&lock);
357 #if (CONFIG_MP_MAX_NUM_CPUS > 1) && defined(CONFIG_SCHED_CPU_MASK)
358 __ASSERT(!arch_is_in_isr() && (arch_current_thread()->base.cpu_mask == BIT(id)), "");
359 #endif
360 id = _current_cpu->id;
361 k_spin_unlock(&lock, key);
362
363 /*
364 * It is assumed that this thread is (still) pinned to
365 * the CPU identified by <id>, and that it is the same CPU
366 * used by arc_vpx_lock().
367 */
368
369 k_sem_give(&vpx_sem[id]);
370 }
371
arc_vpx_unlock_force(unsigned int id)372 void arc_vpx_unlock_force(unsigned int id)
373 {
374 __ASSERT(id < CONFIG_MP_MAX_NUM_CPUS, "");
375
376 k_sem_give(&vpx_sem[id]);
377 }
378
arc_vpx_sem_init(void)379 static int arc_vpx_sem_init(void)
380 {
381 for (unsigned int i = 0; i < CONFIG_MP_MAX_NUM_CPUS; i++) {
382 k_sem_init(vpx_sem, 1, 1);
383 }
384
385 return 0;
386 }
387
388 SYS_INIT(arc_vpx_sem_init, PRE_KERNEL_2, CONFIG_KERNEL_INIT_PRIORITY_OBJECTS);
389 #endif
390
