1 /* $NetBSD: vm_machdep.c,v 1.15 2023/12/20 06:13:58 thorpej Exp $ */ 2 3 /*- 4 * Copyright (c) 2014 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Matt Thomas of 3am Software Foundry. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include "opt_compat_netbsd32.h" 33 #include "opt_ddb.h" 34 35 #include <sys/cdefs.h> 36 __KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.15 2023/12/20 06:13:58 thorpej Exp $"); 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/proc.h> 41 #include <sys/vnode.h> 42 #include <sys/cpu.h> 43 #include <sys/buf.h> 44 #include <sys/exec.h> 45 #include <sys/syslog.h> 46 47 #include <uvm/uvm_extern.h> 48 49 #include <aarch64/pcb.h> 50 #include <aarch64/frame.h> 51 #include <aarch64/machdep.h> 52 #include <aarch64/armreg.h> 53 54 /* 55 * Special compilation symbols: 56 * 57 * STACKCHECKS - Fill undefined and supervisor stacks with a known pattern 58 * on forking and check the pattern on exit, reporting 59 * the amount of stack used. 60 */ 61 62 void 63 cpu_proc_fork(struct proc *p1, struct proc *p2) 64 { 65 } 66 67 /* 68 * Finish a fork operation, with LWP l2 nearly set up. 69 * 70 * Copy and update the pcb and trapframe, making the child ready to run. 71 * 72 * Rig the child's kernel stack so that it will start out in 73 * lwp_trampoline() which will call the specified func with the argument arg. 74 * 75 * If an alternate user-level stack is requested (with non-zero values 76 * in both the stack and stacksize args), set up the user stack pointer 77 * accordingly. 78 */ 79 void 80 cpu_lwp_fork(struct lwp *l1, struct lwp *l2, void *stack, size_t stacksize, 81 void (*func)(void *), void *arg) 82 { 83 const struct pcb * const pcb1 = lwp_getpcb(l1); 84 struct pcb * const pcb2 = lwp_getpcb(l2); 85 86 #if 0 87 printf("cpu_lwp_fork: lwp1=%p, lwp2=%p, curlwp=%p, lwp0=%p\n", 88 l1, l2, curlwp, &lwp0); 89 #endif 90 91 /* Copy the pcb */ 92 *pcb2 = *pcb1; 93 94 /* 95 * Disable FP for a newly created LWP but remember if the 96 * FP state is valid. 97 */ 98 l2->l_md.md_cpacr = CPACR_FPEN_NONE; 99 KASSERT(l2->l_md.md_astpending == 0); 100 101 #ifdef ARMV83_PAC 102 /* 103 * Temporary kern PAC key, not really strong, but better than zero. 104 * The real key gets generated by the new thread in lwp_trampoline(). 105 * 106 * The reason we defer the generation, is because cpu_lwp_fork() can 107 * be called early at boot time, when the CPRNG subsystem hasn't yet 108 * been initialized. 109 */ 110 l2->l_md.md_ia_kern[0] = (uintptr_t)l2; 111 l2->l_md.md_ia_kern[1] = (uintptr_t)stack; 112 113 /* inherit user PAC key */ 114 memcpy(l2->l_md.md_ia_user, l1->l_md.md_ia_user, 115 sizeof(l2->l_md.md_ia_user)); 116 memcpy(l2->l_md.md_ib_user, l1->l_md.md_ib_user, 117 sizeof(l2->l_md.md_ib_user)); 118 memcpy(l2->l_md.md_da_user, l1->l_md.md_da_user, 119 sizeof(l2->l_md.md_da_user)); 120 memcpy(l2->l_md.md_db_user, l1->l_md.md_db_user, 121 sizeof(l2->l_md.md_db_user)); 122 memcpy(l2->l_md.md_ga_user, l1->l_md.md_ga_user, 123 sizeof(l2->l_md.md_ga_user)); 124 #endif 125 126 /* 127 * Set up the kernel stack for the process. 128 * Note: this stack is not in use if we are forking from p1 129 */ 130 vaddr_t uv = uvm_lwp_getuarea(l2); 131 132 #ifdef STACKCHECKS 133 #define PCB_END(l) ((char *)lwp_getpcb((l)) + sizeof(struct pcb)) 134 #define UAREA_END(l) ((char *)uvm_lwp_getuarea((l)) + USPACE) 135 /* fill 0xdd for STACKCHECKS */ 136 memset(PCB_END(l2), 0xdd, UAREA_END(l2) - PCB_END(l2)); 137 printf("lwp %p: pcb=%p, stack=%p-%p\n", l2, lwp_getpcb(l2), 138 PCB_END(l2), UAREA_END(l2)); 139 #endif 140 141 struct trapframe * const utf = (struct trapframe *)(uv + USPACE) - 1; 142 l2->l_md.md_utf = utf; 143 144 *utf = *l1->l_md.md_utf; 145 146 /* 147 * If specified, give the child a different stack (make sure it's 148 * 16- or 8-byte aligned for 64- or 32-bit processes, respectively). 149 */ 150 if (stack != NULL) { 151 utf->tf_sp = (vaddr_t)(stack) + stacksize; 152 #ifdef COMPAT_NETBSD32 153 if (__predict_false(l2->l_proc->p_flag & PK_32)) { 154 utf->tf_sp &= -8; 155 utf->tf_reg[13] = utf->tf_sp; 156 } else 157 #endif 158 utf->tf_sp &= -16; 159 } 160 161 /* build a new switchframe */ 162 struct trapframe * const ktf = utf - 1; 163 ktf->tf_reg[27] = (uint64_t)func; 164 ktf->tf_reg[28] = (uint64_t)arg; 165 ktf->tf_lr = (uintptr_t)lwp_trampoline; 166 #ifdef DDB 167 ktf->tf_reg[29] = (uint64_t)utf; 168 ktf->tf_pc = (uint64_t)&&backtrace_here; 169 ktf->tf_sp = 0; /* mark as switchframe */ 170 backtrace_here: 171 #endif 172 173 pcb2->pcb_tf = ktf; 174 } 175 176 /* 177 * cpu_exit is called as the last action during exit. 178 * 179 * We clean up a little and then call switch_exit() with the old proc as an 180 * argument. switch_exit() first switches to lwp0's context, and finally 181 * jumps into switch() to wait for another process to wake up. 182 */ 183 void 184 cpu_lwp_free(struct lwp *l, int proc) 185 { 186 #ifdef STACKCHECKS 187 /* Report how much stack has been used - debugging */ 188 u_char *stop, *sbottom, *ptr; 189 u_int cnt; 190 191 stop = PCB_END(l); 192 sbottom = UAREA_END(l); 193 for (cnt = 0, ptr = stop; *ptr == 0xdd && ptr <= sbottom; cnt++, ptr++) 194 ; 195 log(LOG_INFO, "lwp %p: %u/%ld bytes are used for EL1 stack\n", 196 l, cnt, sbottom - stop); 197 #endif 198 } 199 200 void 201 cpu_lwp_free2(struct lwp *l) 202 { 203 } 204 205 /* 206 * Map a user I/O request into kernel virtual address space. 207 * Note: the pages are already locked by uvm_vslock(), so we 208 * do not need to pass an access_type to pmap_enter(). 209 */ 210 int 211 vmapbuf(struct buf *bp, vsize_t len) 212 { 213 vaddr_t faddr, taddr, off; 214 paddr_t fpa; 215 216 217 if ((bp->b_flags & B_PHYS) == 0) 218 panic("vmapbuf"); 219 220 bp->b_saveaddr = bp->b_data; 221 faddr = trunc_page((vaddr_t)bp->b_data); 222 off = (vaddr_t)bp->b_data - faddr; 223 len = round_page(off + len); 224 taddr = uvm_km_alloc(phys_map, len, atop(faddr) & uvmexp.colormask, 225 UVM_KMF_VAONLY | UVM_KMF_WAITVA | UVM_KMF_COLORMATCH); 226 bp->b_data = (void *)(taddr + off); 227 228 /* 229 * The region is locked, so we expect that pmap_extract() will return 230 * true. 231 */ 232 while (len) { 233 (void)pmap_extract(vm_map_pmap(&bp->b_proc->p_vmspace->vm_map), 234 faddr, &fpa); 235 pmap_enter(pmap_kernel(), taddr, fpa, 236 VM_PROT_READ | VM_PROT_WRITE, 237 VM_PROT_READ | VM_PROT_WRITE | PMAP_WIRED); 238 faddr += PAGE_SIZE; 239 taddr += PAGE_SIZE; 240 len -= PAGE_SIZE; 241 } 242 pmap_update(pmap_kernel()); 243 244 return 0; 245 } 246 247 /* 248 * Unmap a previously-mapped user I/O request. 249 */ 250 void 251 vunmapbuf(struct buf *bp, vsize_t len) 252 { 253 vaddr_t addr, off; 254 255 if ((bp->b_flags & B_PHYS) == 0) 256 panic("vunmapbuf"); 257 258 /* 259 * Make sure the cache does not have dirty data for the 260 * pages we had mapped. 261 */ 262 addr = trunc_page((vaddr_t)bp->b_data); 263 off = (vaddr_t)bp->b_data - addr; 264 len = round_page(off + len); 265 266 pmap_remove(pmap_kernel(), addr, addr + len); 267 pmap_update(pmap_kernel()); 268 uvm_km_free(phys_map, addr, len, UVM_KMF_VAONLY); 269 bp->b_data = bp->b_saveaddr; 270 bp->b_saveaddr = 0; 271 } 272
Indexes created Sun Oct 25 00:26:45 UTC 2026