zephyr/arch/arc/core/thread.c

251 lines
6.7 KiB
C

/*
* Copyright (c) 2014 Wind River Systems, Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @brief New thread creation for ARCv2
*
* Core thread related primitives for the ARCv2 processor architecture.
*/
#include <kernel.h>
#include <ksched.h>
#include <offsets_short.h>
#include <wait_q.h>
#ifdef CONFIG_USERSPACE
#include <arch/arc/v2/mpu/arc_core_mpu.h>
#endif
/* initial stack frame */
struct init_stack_frame {
uint32_t pc;
#ifdef CONFIG_ARC_HAS_SECURE
uint32_t sec_stat;
#endif
uint32_t status32;
uint32_t r3;
uint32_t r2;
uint32_t r1;
uint32_t r0;
};
#ifdef CONFIG_USERSPACE
struct user_init_stack_frame {
struct init_stack_frame iframe;
uint32_t user_sp;
};
static bool is_user(struct k_thread *thread)
{
return (thread->base.user_options & K_USER) != 0;
}
#endif
/* Set all stack-related architecture variables for the provided thread */
static void setup_stack_vars(struct k_thread *thread)
{
#ifdef CONFIG_USERSPACE
if (is_user(thread)) {
#ifdef CONFIG_GEN_PRIV_STACKS
thread->arch.priv_stack_start =
(uint32_t)z_priv_stack_find(thread->stack_obj);
#else
thread->arch.priv_stack_start = (uint32_t)(thread->stack_obj);
#endif /* CONFIG_GEN_PRIV_STACKS */
thread->arch.priv_stack_start += Z_ARC_STACK_GUARD_SIZE;
} else {
thread->arch.priv_stack_start = 0;
}
#endif /* CONFIG_USERSPACE */
#ifdef CONFIG_ARC_STACK_CHECKING
#ifdef CONFIG_USERSPACE
if (is_user(thread)) {
thread->arch.k_stack_top = thread->arch.priv_stack_start;
thread->arch.k_stack_base = (thread->arch.priv_stack_start +
CONFIG_PRIVILEGED_STACK_SIZE);
thread->arch.u_stack_top = thread->stack_info.start;
thread->arch.u_stack_base = (thread->stack_info.start +
thread->stack_info.size);
} else
#endif /* CONFIG_USERSPACE */
{
thread->arch.k_stack_top = (uint32_t)thread->stack_info.start;
thread->arch.k_stack_base = (uint32_t)(thread->stack_info.start +
thread->stack_info.size);
#ifdef CONFIG_USERSPACE
thread->arch.u_stack_top = 0;
thread->arch.u_stack_base = 0;
#endif /* CONFIG_USERSPACE */
}
#endif /* CONFIG_ARC_STACK_CHECKING */
}
/* Get the initial stack frame pointer from the thread's stack buffer. */
static struct init_stack_frame *get_iframe(struct k_thread *thread,
char *stack_ptr)
{
#ifdef CONFIG_USERSPACE
if (is_user(thread)) {
/* Initial stack frame for a user thread is slightly larger;
* we land in z_user_thread_entry_wrapper on the privilege
* stack, and pop off an additional value for the user
* stack pointer.
*/
struct user_init_stack_frame *uframe;
uframe = Z_STACK_PTR_TO_FRAME(struct user_init_stack_frame,
thread->arch.priv_stack_start +
CONFIG_PRIVILEGED_STACK_SIZE);
uframe->user_sp = (uint32_t)stack_ptr;
return &uframe->iframe;
}
#endif
return Z_STACK_PTR_TO_FRAME(struct init_stack_frame, stack_ptr);
}
/*
* Pre-populate values in the registers inside _callee_saved_stack struct
* so these registers have pre-defined values when new thread begins
* execution. For example, setting up the thread pointer for thread local
* storage here so the thread starts with thread pointer already set up.
*/
static inline void arch_setup_callee_saved_regs(struct k_thread *thread,
uintptr_t stack_ptr)
{
_callee_saved_stack_t *regs = UINT_TO_POINTER(stack_ptr);
ARG_UNUSED(regs);
#ifdef CONFIG_THREAD_LOCAL_STORAGE
/* R26 is used for thread pointer */
regs->r26 = thread->tls;
#endif
}
/*
* The initial context is a basic stack frame that contains arguments for
* z_thread_entry() return address, that points at z_thread_entry()
* and status register.
*/
void 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)
{
struct init_stack_frame *iframe;
setup_stack_vars(thread);
/* Set up initial stack frame */
iframe = get_iframe(thread, stack_ptr);
#ifdef CONFIG_USERSPACE
/* enable US bit, US is read as zero in user mode. This will allow user
* mode sleep instructions, and it enables a form of denial-of-service
* attack by putting the processor in sleep mode, but since interrupt
* level/mask can't be set from user space that's not worse than
* executing a loop without yielding.
*/
iframe->status32 = _ARC_V2_STATUS32_US | _ARC_V2_STATUS32_DZ;
if (is_user(thread)) {
iframe->pc = (uint32_t)z_user_thread_entry_wrapper;
} else {
iframe->pc = (uint32_t)z_thread_entry_wrapper;
}
#else
iframe->status32 = _ARC_V2_STATUS32_DZ;
iframe->pc = ((uint32_t)z_thread_entry_wrapper);
#endif /* CONFIG_USERSPACE */
#ifdef CONFIG_ARC_SECURE_FIRMWARE
iframe->sec_stat = z_arc_v2_aux_reg_read(_ARC_V2_SEC_STAT);
#endif
iframe->r0 = (uint32_t)entry;
iframe->r1 = (uint32_t)p1;
iframe->r2 = (uint32_t)p2;
iframe->r3 = (uint32_t)p3;
#ifdef CONFIG_ARC_STACK_CHECKING
#ifdef CONFIG_ARC_SECURE_FIRMWARE
iframe->sec_stat |= _ARC_V2_SEC_STAT_SSC;
#else
iframe->status32 |= _ARC_V2_STATUS32_SC;
#endif /* CONFIG_ARC_SECURE_FIRMWARE */
#endif /* CONFIG_ARC_STACK_CHECKING */
#ifdef CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS
iframe->status32 |= _ARC_V2_STATUS32_AD;
#endif
/* Set required thread members */
thread->switch_handle = thread;
thread->arch.relinquish_cause = _CAUSE_COOP;
thread->callee_saved.sp =
(uint32_t)iframe - ___callee_saved_stack_t_SIZEOF;
arch_setup_callee_saved_regs(thread, thread->callee_saved.sp);
/* initial values in all other regs/k_thread entries are irrelevant */
}
void *z_arch_get_next_switch_handle(struct k_thread **old_thread)
{
*old_thread = _current;
return z_get_next_switch_handle(*old_thread);
}
#ifdef CONFIG_USERSPACE
FUNC_NORETURN void arch_user_mode_enter(k_thread_entry_t user_entry,
void *p1, void *p2, void *p3)
{
setup_stack_vars(_current);
/* possible optimizaiton: no need to load mem domain anymore */
/* need to lock cpu here ? */
configure_mpu_thread(_current);
z_arc_userspace_enter(user_entry, p1, p2, p3,
(uint32_t)_current->stack_info.start,
(_current->stack_info.size -
_current->stack_info.delta), _current);
CODE_UNREACHABLE;
}
#endif
#if defined(CONFIG_FPU) && defined(CONFIG_FPU_SHARING)
int arch_float_disable(struct k_thread *thread)
{
unsigned int key;
/* Ensure a preemptive context switch does not occur */
key = irq_lock();
/* Disable all floating point capabilities for the thread */
thread->base.user_options &= ~K_FP_REGS;
irq_unlock(key);
return 0;
}
int arch_float_enable(struct k_thread *thread, unsigned int options)
{
unsigned int key;
/* Ensure a preemptive context switch does not occur */
key = irq_lock();
/* Enable all floating point capabilities for the thread */
thread->base.user_options |= K_FP_REGS;
irq_unlock(key);
return 0;
}
#endif /* CONFIG_FPU && CONFIG_FPU_SHARING */