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/sysent.h> 40 #include <sys/unistd.h> 41 42 #include <vm/vm.h> 43 #include <vm/vm_page.h> 44 #include <vm/vm_map.h> 45 #include <vm/uma.h> 46 #include <vm/uma_int.h> 47 48 #include <machine/armreg.h> 49 #include <machine/cpu.h> 50 #include <machine/md_var.h> 51 #include <machine/pcb.h> 52 #include <machine/frame.h> 53 54 #ifdef VFP 55 #include <machine/vfp.h> 56 #endif 57 58 #include <dev/psci/psci.h> 59 60 /* 61 * Finish a fork operation, with process p2 nearly set up. 62 * Copy and update the pcb, set up the stack so that the child 63 * ready to run and return to user mode. 64 */ 65 void 66 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) 67 { 68 struct pcb *pcb2; 69 struct trapframe *tf; 70 71 if ((flags & RFPROC) == 0) 72 return; 73 74 if (td1 == curthread) { 75 /* 76 * Save the tpidr_el0 and the vfp state, these normally happen 77 * in cpu_switch, but if userland changes these then forks 78 * this may not have happened. 79 */ 80 td1->td_pcb->pcb_tpidr_el0 = READ_SPECIALREG(tpidr_el0); 81 td1->td_pcb->pcb_tpidrro_el0 = READ_SPECIALREG(tpidrro_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_proc->p_md.md_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 = td1->td_frame->tf_spsr & PSR_M_32; 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 = td1->td_md.md_saved_daif & ~DAIF_I_MASKED; 116 } 117 118 void 119 cpu_reset(void) 120 { 121 122 psci_reset(); 123 124 printf("cpu_reset failed"); 125 while(1) 126 __asm volatile("wfi" ::: "memory"); 127 } 128 129 void 130 cpu_thread_swapin(struct thread *td) 131 { 132 } 133 134 void 135 cpu_thread_swapout(struct thread *td) 136 { 137 } 138 139 void 140 cpu_set_syscall_retval(struct thread *td, int error) 141 { 142 struct trapframe *frame; 143 144 frame = td->td_frame; 145 146 switch (error) { 147 case 0: 148 frame->tf_x[0] = td->td_retval[0]; 149 frame->tf_x[1] = td->td_retval[1]; 150 frame->tf_spsr &= ~PSR_C; /* carry bit */ 151 break; 152 case ERESTART: 153 frame->tf_elr -= 4; 154 break; 155 case EJUSTRETURN: 156 break; 157 default: 158 frame->tf_spsr |= PSR_C; /* carry bit */ 159 frame->tf_x[0] = SV_ABI_ERRNO(td->td_proc, error); 160 break; 161 } 162 } 163 164 /* 165 * Initialize machine state, mostly pcb and trap frame for a new 166 * thread, about to return to userspace. Put enough state in the new 167 * thread's PCB to get it to go back to the fork_return(), which 168 * finalizes the thread state and handles peculiarities of the first 169 * return to userspace for the new thread. 170 */ 171 void 172 cpu_copy_thread(struct thread *td, struct thread *td0) 173 { 174 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 175 bcopy(td0->td_pcb, td->td_pcb, sizeof(struct pcb)); 176 177 td->td_pcb->pcb_x[8] = (uintptr_t)fork_return; 178 td->td_pcb->pcb_x[9] = (uintptr_t)td; 179 td->td_pcb->pcb_x[PCB_LR] = (uintptr_t)fork_trampoline; 180 td->td_pcb->pcb_sp = (uintptr_t)td->td_frame; 181 td->td_pcb->pcb_fpusaved = &td->td_pcb->pcb_fpustate; 182 td->td_pcb->pcb_vfpcpu = UINT_MAX; 183 184 /* Setup to release spin count in fork_exit(). */ 185 td->td_md.md_spinlock_count = 1; 186 td->td_md.md_saved_daif = td0->td_md.md_saved_daif & ~DAIF_I_MASKED; 187 } 188 189 /* 190 * Set that machine state for performing an upcall that starts 191 * the entry function with the given argument. 192 */ 193 void 194 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg, 195 stack_t *stack) 196 { 197 struct trapframe *tf = td->td_frame; 198 199 /* 32bits processes use r13 for sp */ 200 if (td->td_frame->tf_spsr & PSR_M_32) 201 tf->tf_x[13] = STACKALIGN((uintptr_t)stack->ss_sp + stack->ss_size); 202 else 203 tf->tf_sp = STACKALIGN((uintptr_t)stack->ss_sp + stack->ss_size); 204 tf->tf_elr = (register_t)entry; 205 tf->tf_x[0] = (register_t)arg; 206 } 207 208 int 209 cpu_set_user_tls(struct thread *td, void *tls_base) 210 { 211 struct pcb *pcb; 212 213 if ((uintptr_t)tls_base >= VM_MAXUSER_ADDRESS) 214 return (EINVAL); 215 216 pcb = td->td_pcb; 217 if (td->td_frame->tf_spsr & PSR_M_32) { 218 /* 32bits arm stores the user TLS into tpidrro */ 219 pcb->pcb_tpidrro_el0 = (register_t)tls_base; 220 pcb->pcb_tpidr_el0 = (register_t)tls_base; 221 if (td == curthread) { 222 WRITE_SPECIALREG(tpidrro_el0, tls_base); 223 WRITE_SPECIALREG(tpidr_el0, tls_base); 224 } 225 } else { 226 pcb->pcb_tpidr_el0 = (register_t)tls_base; 227 if (td == curthread) 228 WRITE_SPECIALREG(tpidr_el0, tls_base); 229 } 230 231 return (0); 232 } 233 234 void 235 cpu_thread_exit(struct thread *td) 236 { 237 } 238 239 void 240 cpu_thread_alloc(struct thread *td) 241 { 242 243 td->td_pcb = (struct pcb *)(td->td_kstack + 244 td->td_kstack_pages * PAGE_SIZE) - 1; 245 td->td_frame = (struct trapframe *)STACKALIGN( 246 (struct trapframe *)td->td_pcb - 1); 247 } 248 249 void 250 cpu_thread_free(struct thread *td) 251 { 252 } 253 254 void 255 cpu_thread_clean(struct thread *td) 256 { 257 } 258 259 /* 260 * Intercept the return address from a freshly forked process that has NOT 261 * been scheduled yet. 262 * 263 * This is needed to make kernel threads stay in kernel mode. 264 */ 265 void 266 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg) 267 { 268 269 td->td_pcb->pcb_x[8] = (uintptr_t)func; 270 td->td_pcb->pcb_x[9] = (uintptr_t)arg; 271 td->td_pcb->pcb_x[PCB_LR] = (uintptr_t)fork_trampoline; 272 td->td_pcb->pcb_sp = (uintptr_t)td->td_frame; 273 td->td_pcb->pcb_fpusaved = &td->td_pcb->pcb_fpustate; 274 td->td_pcb->pcb_vfpcpu = UINT_MAX; 275 } 276 277 void 278 cpu_exit(struct thread *td) 279 { 280 } 281 282 void 283 swi_vm(void *v) 284 { 285 286 if (busdma_swi_pending != 0) 287 busdma_swi(); 288 } 289