1 /*- 2 * Copyright (c) 2014 Andrew Turner 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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. 13 * 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 24 * SUCH DAMAGE. 25 * 26 */ 27 28 #include "opt_platform.h" 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/limits.h> 36 #include <sys/proc.h> 37 #include <sys/sf_buf.h> 38 #include <sys/signal.h> 39 #include <sys/unistd.h> 40 41 #include <vm/vm.h> 42 #include <vm/vm_page.h> 43 #include <vm/vm_map.h> 44 #include <vm/uma.h> 45 #include <vm/uma_int.h> 46 47 #include <machine/armreg.h> 48 #include <machine/cpu.h> 49 #include <machine/md_var.h> 50 #include <machine/pcb.h> 51 #include <machine/frame.h> 52 53 #ifdef VFP 54 #include <machine/vfp.h> 55 #endif 56 57 #ifdef DEV_PSCI 58 #include <dev/psci/psci.h> 59 #endif 60 61 /* 62 * Finish a fork operation, with process p2 nearly set up. 63 * Copy and update the pcb, set up the stack so that the child 64 * ready to run and return to user mode. 65 */ 66 void 67 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) 68 { 69 struct pcb *pcb2; 70 struct trapframe *tf; 71 72 if ((flags & RFPROC) == 0) 73 return; 74 75 if (td1 == curthread) { 76 /* 77 * Save the tpidr_el0 and the vfp state, these normally happen 78 * in cpu_switch, but if userland changes these then forks 79 * this may not have happened. 80 */ 81 td1->td_pcb->pcb_tpidr_el0 = READ_SPECIALREG(tpidr_el0); 82 #ifdef VFP 83 if ((td1->td_pcb->pcb_fpflags & PCB_FP_STARTED) != 0) 84 vfp_save_state(td1, td1->td_pcb); 85 #endif 86 } 87 88 pcb2 = (struct pcb *)(td2->td_kstack + 89 td2->td_kstack_pages * PAGE_SIZE) - 1; 90 91 td2->td_pcb = pcb2; 92 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 93 94 td2->td_pcb->pcb_l0addr = 95 vtophys(vmspace_pmap(td2->td_proc->p_vmspace)->pm_l0); 96 97 tf = (struct trapframe *)STACKALIGN((struct trapframe *)pcb2 - 1); 98 bcopy(td1->td_frame, tf, sizeof(*tf)); 99 tf->tf_x[0] = 0; 100 tf->tf_x[1] = 0; 101 tf->tf_spsr = 0; 102 103 td2->td_frame = tf; 104 105 /* Set the return value registers for fork() */ 106 td2->td_pcb->pcb_x[8] = (uintptr_t)fork_return; 107 td2->td_pcb->pcb_x[9] = (uintptr_t)td2; 108 td2->td_pcb->pcb_x[PCB_LR] = (uintptr_t)fork_trampoline; 109 td2->td_pcb->pcb_sp = (uintptr_t)td2->td_frame; 110 td2->td_pcb->pcb_fpusaved = &td2->td_pcb->pcb_fpustate; 111 td2->td_pcb->pcb_vfpcpu = UINT_MAX; 112 113 /* Setup to release spin count in fork_exit(). */ 114 td2->td_md.md_spinlock_count = 1; 115 td2->td_md.md_saved_daif = 0; 116 } 117 118 void 119 cpu_reset(void) 120 { 121 122 #ifdef DEV_PSCI 123 psci_reset(); 124 #endif 125 126 printf("cpu_reset failed"); 127 while(1) 128 __asm volatile("wfi" ::: "memory"); 129 } 130 131 void 132 cpu_thread_swapin(struct thread *td) 133 { 134 } 135 136 void 137 cpu_thread_swapout(struct thread *td) 138 { 139 } 140 141 void 142 cpu_set_syscall_retval(struct thread *td, int error) 143 { 144 struct trapframe *frame; 145 146 frame = td->td_frame; 147 148 switch (error) { 149 case 0: 150 frame->tf_x[0] = td->td_retval[0]; 151 frame->tf_x[1] = td->td_retval[1]; 152 frame->tf_spsr &= ~PSR_C; /* carry bit */ 153 break; 154 case ERESTART: 155 frame->tf_elr -= 4; 156 break; 157 case EJUSTRETURN: 158 break; 159 default: 160 frame->tf_spsr |= PSR_C; /* carry bit */ 161 frame->tf_x[0] = error; 162 break; 163 } 164 } 165 166 /* 167 * Initialize machine state, mostly pcb and trap frame for a new 168 * thread, about to return to userspace. Put enough state in the new 169 * thread's PCB to get it to go back to the fork_return(), which 170 * finalizes the thread state and handles peculiarities of the first 171 * return to userspace for the new thread. 172 */ 173 void 174 cpu_copy_thread(struct thread *td, struct thread *td0) 175 { 176 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 177 bcopy(td0->td_pcb, td->td_pcb, sizeof(struct pcb)); 178 179 td->td_pcb->pcb_x[8] = (uintptr_t)fork_return; 180 td->td_pcb->pcb_x[9] = (uintptr_t)td; 181 td->td_pcb->pcb_x[PCB_LR] = (uintptr_t)fork_trampoline; 182 td->td_pcb->pcb_sp = (uintptr_t)td->td_frame; 183 td->td_pcb->pcb_fpusaved = &td->td_pcb->pcb_fpustate; 184 td->td_pcb->pcb_vfpcpu = UINT_MAX; 185 186 /* Setup to release spin count in fork_exit(). */ 187 td->td_md.md_spinlock_count = 1; 188 td->td_md.md_saved_daif = 0; 189 } 190 191 /* 192 * Set that machine state for performing an upcall that starts 193 * the entry function with the given argument. 194 */ 195 void 196 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg, 197 stack_t *stack) 198 { 199 struct trapframe *tf = td->td_frame; 200 201 tf->tf_sp = STACKALIGN((uintptr_t)stack->ss_sp + stack->ss_size); 202 tf->tf_elr = (register_t)entry; 203 tf->tf_x[0] = (register_t)arg; 204 } 205 206 int 207 cpu_set_user_tls(struct thread *td, void *tls_base) 208 { 209 struct pcb *pcb; 210 211 if ((uintptr_t)tls_base >= VM_MAXUSER_ADDRESS) 212 return (EINVAL); 213 214 pcb = td->td_pcb; 215 pcb->pcb_tpidr_el0 = (register_t)tls_base; 216 if (td == curthread) 217 WRITE_SPECIALREG(tpidr_el0, tls_base); 218 219 return (0); 220 } 221 222 void 223 cpu_thread_exit(struct thread *td) 224 { 225 } 226 227 void 228 cpu_thread_alloc(struct thread *td) 229 { 230 231 td->td_pcb = (struct pcb *)(td->td_kstack + 232 td->td_kstack_pages * PAGE_SIZE) - 1; 233 td->td_frame = (struct trapframe *)STACKALIGN( 234 td->td_pcb - 1); 235 } 236 237 void 238 cpu_thread_free(struct thread *td) 239 { 240 } 241 242 void 243 cpu_thread_clean(struct thread *td) 244 { 245 } 246 247 /* 248 * Intercept the return address from a freshly forked process that has NOT 249 * been scheduled yet. 250 * 251 * This is needed to make kernel threads stay in kernel mode. 252 */ 253 void 254 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg) 255 { 256 257 td->td_pcb->pcb_x[8] = (uintptr_t)func; 258 td->td_pcb->pcb_x[9] = (uintptr_t)arg; 259 td->td_pcb->pcb_x[PCB_LR] = (uintptr_t)fork_trampoline; 260 td->td_pcb->pcb_sp = (uintptr_t)td->td_frame; 261 td->td_pcb->pcb_fpusaved = &td->td_pcb->pcb_fpustate; 262 td->td_pcb->pcb_vfpcpu = UINT_MAX; 263 } 264 265 void 266 cpu_exit(struct thread *td) 267 { 268 } 269 270 void 271 swi_vm(void *v) 272 { 273 274 if (busdma_swi_pending != 0) 275 busdma_swi(); 276 } 277