2 * Copyright (c) 2014 Andrew Turner
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/limits.h>
35 #include <sys/sf_buf.h>
36 #include <sys/signal.h>
37 #include <sys/unistd.h>
40 #include <vm/vm_page.h>
41 #include <vm/vm_map.h>
43 #include <vm/uma_int.h>
45 #include <machine/armreg.h>
46 #include <machine/cpu.h>
47 #include <machine/md_var.h>
48 #include <machine/pcb.h>
49 #include <machine/frame.h>
52 #include <machine/vfp.h>
56 * Finish a fork operation, with process p2 nearly set up.
57 * Copy and update the pcb, set up the stack so that the child
58 * ready to run and return to user mode.
61 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
66 if ((flags & RFPROC) == 0)
69 if (td1 == curthread) {
71 * Save the tpidr_el0 and the vfp state, these normally happen
72 * in cpu_switch, but if userland changes these then forks
73 * this may not have happened.
75 td1->td_pcb->pcb_tpidr_el0 = READ_SPECIALREG(tpidr_el0);
77 if ((td1->td_pcb->pcb_fpflags & PCB_FP_STARTED) != 0)
78 vfp_save_state(td1, td1->td_pcb);
82 pcb2 = (struct pcb *)(td2->td_kstack +
83 td2->td_kstack_pages * PAGE_SIZE) - 1;
86 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
88 td2->td_pcb->pcb_l0addr =
89 vtophys(vmspace_pmap(td2->td_proc->p_vmspace)->pm_l0);
91 tf = (struct trapframe *)STACKALIGN((struct trapframe *)pcb2 - 1);
92 bcopy(td1->td_frame, tf, sizeof(*tf));
99 /* Set the return value registers for fork() */
100 td2->td_pcb->pcb_x[8] = (uintptr_t)fork_return;
101 td2->td_pcb->pcb_x[9] = (uintptr_t)td2;
102 td2->td_pcb->pcb_x[PCB_LR] = (uintptr_t)fork_trampoline;
103 td2->td_pcb->pcb_sp = (uintptr_t)td2->td_frame;
104 td2->td_pcb->pcb_vfpcpu = UINT_MAX;
106 /* Setup to release spin count in fork_exit(). */
107 td2->td_md.md_spinlock_count = 1;
108 td2->td_md.md_saved_daif = 0;
117 __asm volatile("wfi" ::: "memory");
121 cpu_thread_swapin(struct thread *td)
126 cpu_thread_swapout(struct thread *td)
131 cpu_set_syscall_retval(struct thread *td, int error)
133 struct trapframe *frame;
135 frame = td->td_frame;
139 frame->tf_x[0] = td->td_retval[0];
140 frame->tf_x[1] = td->td_retval[1];
141 frame->tf_spsr &= ~PSR_C; /* carry bit */
149 frame->tf_spsr |= PSR_C; /* carry bit */
150 frame->tf_x[0] = error;
156 * Initialize machine state, mostly pcb and trap frame for a new
157 * thread, about to return to userspace. Put enough state in the new
158 * thread's PCB to get it to go back to the fork_return(), which
159 * finalizes the thread state and handles peculiarities of the first
160 * return to userspace for the new thread.
163 cpu_copy_thread(struct thread *td, struct thread *td0)
165 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
166 bcopy(td0->td_pcb, td->td_pcb, sizeof(struct pcb));
168 td->td_pcb->pcb_x[8] = (uintptr_t)fork_return;
169 td->td_pcb->pcb_x[9] = (uintptr_t)td;
170 td->td_pcb->pcb_x[PCB_LR] = (uintptr_t)fork_trampoline;
171 td->td_pcb->pcb_sp = (uintptr_t)td->td_frame;
172 td->td_pcb->pcb_vfpcpu = UINT_MAX;
174 /* Setup to release spin count in fork_exit(). */
175 td->td_md.md_spinlock_count = 1;
176 td->td_md.md_saved_daif = 0;
180 * Set that machine state for performing an upcall that starts
181 * the entry function with the given argument.
184 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg,
187 struct trapframe *tf = td->td_frame;
189 tf->tf_sp = STACKALIGN((uintptr_t)stack->ss_sp + stack->ss_size);
190 tf->tf_elr = (register_t)entry;
191 tf->tf_x[0] = (register_t)arg;
195 cpu_set_user_tls(struct thread *td, void *tls_base)
199 if ((uintptr_t)tls_base >= VM_MAXUSER_ADDRESS)
203 pcb->pcb_tpidr_el0 = (register_t)tls_base;
205 WRITE_SPECIALREG(tpidr_el0, tls_base);
211 cpu_thread_exit(struct thread *td)
216 cpu_thread_alloc(struct thread *td)
219 td->td_pcb = (struct pcb *)(td->td_kstack +
220 td->td_kstack_pages * PAGE_SIZE) - 1;
221 td->td_frame = (struct trapframe *)STACKALIGN(
226 cpu_thread_free(struct thread *td)
231 cpu_thread_clean(struct thread *td)
236 * Intercept the return address from a freshly forked process that has NOT
237 * been scheduled yet.
239 * This is needed to make kernel threads stay in kernel mode.
242 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg)
245 td->td_pcb->pcb_x[8] = (uintptr_t)func;
246 td->td_pcb->pcb_x[9] = (uintptr_t)arg;
247 td->td_pcb->pcb_x[PCB_LR] = (uintptr_t)fork_trampoline;
248 td->td_pcb->pcb_sp = (uintptr_t)td->td_frame;
249 td->td_pcb->pcb_vfpcpu = UINT_MAX;
253 cpu_exit(struct thread *td)
261 if (busdma_swi_pending != 0)