1 /* $NetBSD: efi_machdep.c,v 1.13 2022/05/03 20:10:20 skrll Exp $ */ 2 3 /*- 4 * Copyright (c) 2018 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jared McNeill <jmcneill@invisible.ca>. 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 <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: efi_machdep.c,v 1.13 2022/05/03 20:10:20 skrll Exp $"); 34 35 #include <sys/param.h> 36 #include <uvm/uvm_extern.h> 37 38 #include <arm/cpufunc.h> 39 40 #include <arm/arm/efi_runtime.h> 41 42 #include <aarch64/machdep.h> 43 44 static struct { 45 struct faultbuf faultbuf; 46 bool fpu_used; 47 } arm_efirt_state; 48 49 static bool efi_userva = true; 50 51 void 52 arm_efirt_md_map_range(vaddr_t va, paddr_t pa, size_t sz, 53 enum arm_efirt_mem_type type) 54 { 55 int flags = 0; 56 int prot = 0; 57 58 switch (type) { 59 case ARM_EFIRT_MEM_CODE: 60 /* need write permission because fw devs */ 61 prot = VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE; 62 break; 63 case ARM_EFIRT_MEM_DATA: 64 prot = VM_PROT_READ | VM_PROT_WRITE; 65 break; 66 case ARM_EFIRT_MEM_MMIO: 67 prot = VM_PROT_READ | VM_PROT_WRITE; 68 flags = PMAP_DEV; 69 break; 70 default: 71 panic("%s: unsupported type %d", __func__, type); 72 } 73 74 /* even if TBI is disabled, AARCH64_ADDRTOP_TAG means KVA */ 75 bool kva = (va & AARCH64_ADDRTOP_TAG) != 0; 76 if (kva) { 77 if (va < EFI_RUNTIME_VA || 78 va >= EFI_RUNTIME_VA + EFI_RUNTIME_SIZE) { 79 printf("Incorrect EFI mapping address %" PRIxVADDR "\n", va); 80 return; 81 } 82 efi_userva = false; 83 } else { 84 if (!efi_userva) { 85 printf("Can't mix EFI RT address spaces\n"); 86 return; 87 } 88 } 89 90 while (sz != 0) { 91 if (kva) { 92 pmap_kenter_pa(va, pa, prot, flags); 93 } else { 94 pmap_enter(pmap_efirt(), va, pa, prot, flags | PMAP_WIRED); 95 } 96 va += PAGE_SIZE; 97 pa += PAGE_SIZE; 98 sz -= PAGE_SIZE; 99 } 100 if (kva) 101 pmap_update(pmap_kernel()); 102 else 103 pmap_update(pmap_efirt()); 104 } 105 106 int 107 arm_efirt_md_enter(void) 108 { 109 kpreempt_disable(); 110 111 struct lwp * const l = curlwp; 112 113 /* Save FPU state */ 114 arm_efirt_state.fpu_used = fpu_used_p(l) != 0; 115 if (arm_efirt_state.fpu_used) 116 fpu_save(l); 117 118 /* Enable FP access (AArch64 UEFI calling convention) */ 119 reg_cpacr_el1_write(CPACR_FPEN_ALL); 120 isb(); 121 122 /* 123 * Install custom fault handler. EFI lock is held across calls so 124 * shared faultbuf is safe here. 125 */ 126 int err = cpu_set_onfault(&arm_efirt_state.faultbuf); 127 if (err) 128 return err; 129 130 if (efi_userva) { 131 if ((l->l_flag & LW_SYSTEM) == 0) { 132 pmap_deactivate(l); 133 } 134 pmap_activate_efirt(); 135 } 136 137 return 0; 138 } 139 140 void 141 arm_efirt_md_exit(void) 142 { 143 struct lwp * const l = curlwp; 144 145 if (efi_userva) { 146 pmap_deactivate_efirt(); 147 if ((l->l_flag & LW_SYSTEM) == 0) { 148 pmap_activate(l); 149 } 150 } 151 152 /* Disable FP access */ 153 reg_cpacr_el1_write(CPACR_FPEN_NONE); 154 isb(); 155 156 /* Restore FPU state */ 157 if (arm_efirt_state.fpu_used) 158 fpu_load(l); 159 160 /* Remove custom fault handler */ 161 cpu_unset_onfault(); 162 163 kpreempt_enable(); 164 } 165