2 * Copyright (c) 2015-2018 Ruslan Bukin <br@bsdpad.com>
5 * Portions of this software were developed by SRI International and the
6 * University of Cambridge Computer Laboratory under DARPA/AFRL contract
7 * FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme.
9 * Portions of this software were developed by the University of Cambridge
10 * Computer Laboratory as part of the CTSRD Project, with support from the
11 * UK Higher Education Innovation Fund (HEIF).
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/limits.h>
42 #include <sys/sf_buf.h>
43 #include <sys/signal.h>
44 #include <sys/unistd.h>
47 #include <vm/vm_page.h>
48 #include <vm/vm_map.h>
50 #include <vm/uma_int.h>
52 #include <machine/riscvreg.h>
53 #include <machine/cpu.h>
54 #include <machine/pcb.h>
55 #include <machine/frame.h>
56 #include <machine/sbi.h>
58 #if __riscv_xlen == 64
59 #define TP_OFFSET 16 /* sizeof(struct tcb) */
63 * Finish a fork operation, with process p2 nearly set up.
64 * Copy and update the pcb, set up the stack so that the child
65 * ready to run and return to user mode.
68 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
73 if ((flags & RFPROC) == 0)
76 /* RISCVTODO: save the FPU state here */
78 pcb2 = (struct pcb *)(td2->td_kstack +
79 td2->td_kstack_pages * PAGE_SIZE) - 1;
82 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
84 tf = (struct trapframe *)STACKALIGN((struct trapframe *)pcb2 - 1);
85 bcopy(td1->td_frame, tf, sizeof(*tf));
87 /* Clear syscall error flag */
90 /* Arguments for child */
93 tf->tf_sstatus |= (SSTATUS_SPIE); /* Enable interrupts. */
94 tf->tf_sstatus &= ~(SSTATUS_SPP); /* User mode. */
98 /* Set the return value registers for fork() */
99 td2->td_pcb->pcb_s[0] = (uintptr_t)fork_return;
100 td2->td_pcb->pcb_s[1] = (uintptr_t)td2;
101 td2->td_pcb->pcb_ra = (uintptr_t)fork_trampoline;
102 td2->td_pcb->pcb_sp = (uintptr_t)td2->td_frame;
104 /* Setup to release spin count in fork_exit(). */
105 td2->td_md.md_spinlock_count = 1;
106 td2->td_md.md_saved_sstatus_ie = (SSTATUS_SIE);
119 cpu_thread_swapin(struct thread *td)
124 cpu_thread_swapout(struct thread *td)
129 cpu_set_syscall_retval(struct thread *td, int error)
131 struct trapframe *frame;
133 frame = td->td_frame;
137 frame->tf_a[0] = td->td_retval[0];
138 frame->tf_a[1] = td->td_retval[1];
139 frame->tf_t[0] = 0; /* syscall succeeded */
142 frame->tf_sepc -= 4; /* prev instruction */
147 frame->tf_a[0] = error;
148 frame->tf_t[0] = 1; /* syscall error */
154 * Initialize machine state, mostly pcb and trap frame for a new
155 * thread, about to return to userspace. Put enough state in the new
156 * thread's PCB to get it to go back to the fork_return(), which
157 * finalizes the thread state and handles peculiarities of the first
158 * return to userspace for the new thread.
161 cpu_copy_thread(struct thread *td, struct thread *td0)
164 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
165 bcopy(td0->td_pcb, td->td_pcb, sizeof(struct pcb));
167 td->td_pcb->pcb_s[0] = (uintptr_t)fork_return;
168 td->td_pcb->pcb_s[1] = (uintptr_t)td;
169 td->td_pcb->pcb_ra = (uintptr_t)fork_trampoline;
170 td->td_pcb->pcb_sp = (uintptr_t)td->td_frame;
172 /* Setup to release spin count in fork_exit(). */
173 td->td_md.md_spinlock_count = 1;
174 td->td_md.md_saved_sstatus_ie = (SSTATUS_SIE);
178 * Set that machine state for performing an upcall that starts
179 * the entry function with the given argument.
182 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg,
185 struct trapframe *tf;
189 tf->tf_sp = STACKALIGN((uintptr_t)stack->ss_sp + stack->ss_size);
190 tf->tf_sepc = (register_t)entry;
191 tf->tf_a[0] = (register_t)arg;
195 cpu_set_user_tls(struct thread *td, void *tls_base)
198 if ((uintptr_t)tls_base >= VM_MAXUSER_ADDRESS)
202 * The user TLS is set by modifying the trapframe's tp value, which
203 * will be restored when returning to userspace.
205 td->td_frame->tf_tp = (register_t)tls_base + TP_OFFSET;
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(
222 (caddr_t)td->td_pcb - 8 - sizeof(struct trapframe));
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_s[0] = (uintptr_t)func;
246 td->td_pcb->pcb_s[1] = (uintptr_t)arg;
247 td->td_pcb->pcb_ra = (uintptr_t)fork_trampoline;
248 td->td_pcb->pcb_sp = (uintptr_t)td->td_frame;
252 cpu_exit(struct thread *td)
257 cpu_exec_vmspace_reuse(struct proc *p __unused, vm_map_t map __unused)
264 cpu_procctl(struct thread *td __unused, int idtype __unused, id_t id __unused,
265 int com __unused, void *data __unused)
275 /* Nothing to do here - busdma bounce buffers are not implemented. */