1/* SPDX-License-Identifier: GPL-2.0-or-later */ 2/* 3 * Copyright (c) 2012 Linaro Limited. 4 */ 5 6#include <linux/init.h> 7#include <linux/irqchip/arm-gic-v3.h> 8#include <linux/linkage.h> 9#include <asm/assembler.h> 10#include <asm/virt.h> 11 12#ifndef ZIMAGE 13/* 14 * For the kernel proper, we need to find out the CPU boot mode long after 15 * boot, so we need to store it in a writable variable. 16 * 17 * This is not in .bss, because we set it sufficiently early that the boot-time 18 * zeroing of .bss would clobber it. 19 */ 20.data 21 .align 2 22ENTRY(__boot_cpu_mode) 23 .long 0 24.text 25 26 /* 27 * Save the primary CPU boot mode. Requires 3 scratch registers. 28 */ 29 .macro store_primary_cpu_mode reg1, reg2, reg3 30 mrs \reg1, cpsr 31 and \reg1, \reg1, #MODE_MASK 32 adr \reg2, .L__boot_cpu_mode_offset 33 ldr \reg3, [\reg2] 34 str \reg1, [\reg2, \reg3] 35 .endm 36 37 /* 38 * Compare the current mode with the one saved on the primary CPU. 39 * If they don't match, record that fact. The Z bit indicates 40 * if there's a match or not. 41 * Requires 3 additionnal scratch registers. 42 */ 43 .macro compare_cpu_mode_with_primary mode, reg1, reg2, reg3 44 adr \reg2, .L__boot_cpu_mode_offset 45 ldr \reg3, [\reg2] 46 ldr \reg1, [\reg2, \reg3] 47 cmp \mode, \reg1 @ matches primary CPU boot mode? 48 orrne \reg1, \reg1, #BOOT_CPU_MODE_MISMATCH 49 strne \reg1, [\reg2, \reg3] @ record what happened and give up 50 .endm 51 52#else /* ZIMAGE */ 53 54 .macro store_primary_cpu_mode reg1:req, reg2:req, reg3:req 55 .endm 56 57/* 58 * The zImage loader only runs on one CPU, so we don't bother with mult-CPU 59 * consistency checking: 60 */ 61 .macro compare_cpu_mode_with_primary mode, reg1, reg2, reg3 62 cmp \mode, \mode 63 .endm 64 65#endif /* ZIMAGE */ 66 67/* 68 * Hypervisor stub installation functions. 69 * 70 * These must be called with the MMU and D-cache off. 71 * They are not ABI compliant and are only intended to be called from the kernel 72 * entry points in head.S. 73 */ 74@ Call this from the primary CPU 75ENTRY(__hyp_stub_install) 76 store_primary_cpu_mode r4, r5, r6 77ENDPROC(__hyp_stub_install) 78 79 @ fall through... 80 81@ Secondary CPUs should call here 82ENTRY(__hyp_stub_install_secondary) 83 mrs r4, cpsr 84 and r4, r4, #MODE_MASK 85 86 /* 87 * If the secondary has booted with a different mode, give up 88 * immediately. 89 */ 90 compare_cpu_mode_with_primary r4, r5, r6, r7 91 retne lr 92 93 /* 94 * Once we have given up on one CPU, we do not try to install the 95 * stub hypervisor on the remaining ones: because the saved boot mode 96 * is modified, it can't compare equal to the CPSR mode field any 97 * more. 98 * 99 * Otherwise... 100 */ 101 102 cmp r4, #HYP_MODE 103 retne lr @ give up if the CPU is not in HYP mode 104 105/* 106 * Configure HSCTLR to set correct exception endianness/instruction set 107 * state etc. 108 * Turn off all traps 109 * Eventually, CPU-specific code might be needed -- assume not for now 110 * 111 * This code relies on the "eret" instruction to synchronize the 112 * various coprocessor accesses. This is done when we switch to SVC 113 * (see safe_svcmode_maskall). 114 */ 115 @ Now install the hypervisor stub: 116 W(adr) r7, __hyp_stub_vectors 117 mcr p15, 4, r7, c12, c0, 0 @ set hypervisor vector base (HVBAR) 118 119 @ Disable all traps, so we don't get any nasty surprise 120 mov r7, #0 121 mcr p15, 4, r7, c1, c1, 0 @ HCR 122 mcr p15, 4, r7, c1, c1, 2 @ HCPTR 123 mcr p15, 4, r7, c1, c1, 3 @ HSTR 124 125THUMB( orr r7, #(1 << 30) ) @ HSCTLR.TE 126ARM_BE8(orr r7, r7, #(1 << 25)) @ HSCTLR.EE 127 mcr p15, 4, r7, c1, c0, 0 @ HSCTLR 128 129 mrc p15, 4, r7, c1, c1, 1 @ HDCR 130 and r7, #0x1f @ Preserve HPMN 131 mcr p15, 4, r7, c1, c1, 1 @ HDCR 132 133 @ Make sure NS-SVC is initialised appropriately 134 mrc p15, 0, r7, c1, c0, 0 @ SCTLR 135 orr r7, #(1 << 5) @ CP15 barriers enabled 136 bic r7, #(3 << 7) @ Clear SED/ITD for v8 (RES0 for v7) 137 bic r7, #(3 << 19) @ WXN and UWXN disabled 138 mcr p15, 0, r7, c1, c0, 0 @ SCTLR 139 140 mrc p15, 0, r7, c0, c0, 0 @ MIDR 141 mcr p15, 4, r7, c0, c0, 0 @ VPIDR 142 143 mrc p15, 0, r7, c0, c0, 5 @ MPIDR 144 mcr p15, 4, r7, c0, c0, 5 @ VMPIDR 145 146#if !defined(ZIMAGE) && defined(CONFIG_ARM_ARCH_TIMER) 147 @ make CNTP_* and CNTPCT accessible from PL1 148 mrc p15, 0, r7, c0, c1, 1 @ ID_PFR1 149 lsr r7, #16 150 and r7, #0xf 151 cmp r7, #1 152 bne 1f 153 mrc p15, 4, r7, c14, c1, 0 @ CNTHCTL 154 orr r7, r7, #3 @ PL1PCEN | PL1PCTEN 155 mcr p15, 4, r7, c14, c1, 0 @ CNTHCTL 156 mov r7, #0 157 mcrr p15, 4, r7, r7, c14 @ CNTVOFF 158 159 @ Disable virtual timer in case it was counting 160 mrc p15, 0, r7, c14, c3, 1 @ CNTV_CTL 161 bic r7, #1 @ Clear ENABLE 162 mcr p15, 0, r7, c14, c3, 1 @ CNTV_CTL 1631: 164#endif 165 166#ifdef CONFIG_ARM_GIC_V3 167 @ Check whether GICv3 system registers are available 168 mrc p15, 0, r7, c0, c1, 1 @ ID_PFR1 169 ubfx r7, r7, #28, #4 170 teq r7, #0 171 beq 2f 172 173 @ Enable system register accesses 174 mrc p15, 4, r7, c12, c9, 5 @ ICC_HSRE 175 orr r7, r7, #(ICC_SRE_EL2_ENABLE | ICC_SRE_EL2_SRE) 176 mcr p15, 4, r7, c12, c9, 5 @ ICC_HSRE 177 isb 178 179 @ SRE bit could be forced to 0 by firmware. 180 @ Check whether it sticks before accessing any other sysreg 181 mrc p15, 4, r7, c12, c9, 5 @ ICC_HSRE 182 tst r7, #ICC_SRE_EL2_SRE 183 beq 2f 184 mov r7, #0 185 mcr p15, 4, r7, c12, c11, 0 @ ICH_HCR 1862: 187#endif 188 189 bx lr @ The boot CPU mode is left in r4. 190ENDPROC(__hyp_stub_install_secondary) 191 192__hyp_stub_do_trap: 193 teq r0, #HVC_SET_VECTORS 194 bne 1f 195 mcr p15, 4, r1, c12, c0, 0 @ set HVBAR 196 b __hyp_stub_exit 197 1981: teq r0, #HVC_SOFT_RESTART 199 bne 1f 200 bx r1 201 2021: teq r0, #HVC_RESET_VECTORS 203 beq __hyp_stub_exit 204 205 ldr r0, =HVC_STUB_ERR 206 __ERET 207 208__hyp_stub_exit: 209 mov r0, #0 210 __ERET 211ENDPROC(__hyp_stub_do_trap) 212 213/* 214 * __hyp_set_vectors: Call this after boot to set the initial hypervisor 215 * vectors as part of hypervisor installation. On an SMP system, this should 216 * be called on each CPU. 217 * 218 * r0 must be the physical address of the new vector table (which must lie in 219 * the bottom 4GB of physical address space. 220 * 221 * r0 must be 32-byte aligned. 222 * 223 * Before calling this, you must check that the stub hypervisor is installed 224 * everywhere, by waiting for any secondary CPUs to be brought up and then 225 * checking that BOOT_CPU_MODE_HAVE_HYP(__boot_cpu_mode) is true. 226 * 227 * If not, there is a pre-existing hypervisor, some CPUs failed to boot, or 228 * something else went wrong... in such cases, trying to install a new 229 * hypervisor is unlikely to work as desired. 230 * 231 * When you call into your shiny new hypervisor, sp_hyp will contain junk, 232 * so you will need to set that to something sensible at the new hypervisor's 233 * initialisation entry point. 234 */ 235ENTRY(__hyp_set_vectors) 236 mov r1, r0 237 mov r0, #HVC_SET_VECTORS 238 __HVC(0) 239 ret lr 240ENDPROC(__hyp_set_vectors) 241 242ENTRY(__hyp_soft_restart) 243 mov r1, r0 244 mov r0, #HVC_SOFT_RESTART 245 __HVC(0) 246 ret lr 247ENDPROC(__hyp_soft_restart) 248 249ENTRY(__hyp_reset_vectors) 250 mov r0, #HVC_RESET_VECTORS 251 __HVC(0) 252 ret lr 253ENDPROC(__hyp_reset_vectors) 254 255#ifndef ZIMAGE 256.align 2 257.L__boot_cpu_mode_offset: 258 .long __boot_cpu_mode - . 259#endif 260 261.align 5 262ENTRY(__hyp_stub_vectors) 263__hyp_stub_reset: W(b) . 264__hyp_stub_und: W(b) . 265__hyp_stub_svc: W(b) . 266__hyp_stub_pabort: W(b) . 267__hyp_stub_dabort: W(b) . 268__hyp_stub_trap: W(b) __hyp_stub_do_trap 269__hyp_stub_irq: W(b) . 270__hyp_stub_fiq: W(b) . 271ENDPROC(__hyp_stub_vectors) 272 273