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 .arch armv7-a 13 14 #ifndef ZIMAGE 15 /* 16 * For the kernel proper, we need to find out the CPU boot mode long after 17 * boot, so we need to store it in a writable variable. 18 * 19 * This is not in .bss, because we set it sufficiently early that the boot-time 20 * zeroing of .bss would clobber it. 21 */ 22 .data 23 .align 2 24 ENTRY(__boot_cpu_mode) 25 .long 0 26 .text 27 28 /* 29 * Save the primary CPU boot mode. Requires 2 scratch registers. 30 */ 31 .macro store_primary_cpu_mode reg1, reg2 32 mrs \reg1, cpsr 33 and \reg1, \reg1, #MODE_MASK 34 str_l \reg1, __boot_cpu_mode, \reg2 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 2 additional scratch registers. 42 */ 43 .macro compare_cpu_mode_with_primary mode, reg1, reg2 44 adr_l \reg2, __boot_cpu_mode 45 ldr \reg1, [\reg2] 46 cmp \mode, \reg1 @ matches primary CPU boot mode? 47 orrne \reg1, \reg1, #BOOT_CPU_MODE_MISMATCH 48 strne \reg1, [\reg2] @ record what happened and give up 49 .endm 50 51 #else /* ZIMAGE */ 52 53 .macro store_primary_cpu_mode reg1:req, reg2:req 54 .endm 55 56 /* 57 * The zImage loader only runs on one CPU, so we don't bother with mult-CPU 58 * consistency checking: 59 */ 60 .macro compare_cpu_mode_with_primary mode, reg1, reg2 61 cmp \mode, \mode 62 .endm 63 64 #endif /* ZIMAGE */ 65 66 /* 67 * Hypervisor stub installation functions. 68 * 69 * These must be called with the MMU and D-cache off. 70 * They are not ABI compliant and are only intended to be called from the kernel 71 * entry points in head.S. 72 */ 73 @ Call this from the primary CPU 74 ENTRY(__hyp_stub_install) 75 store_primary_cpu_mode r4, r5 76 ENDPROC(__hyp_stub_install) 77 78 @ fall through... 79 80 @ Secondary CPUs should call here 81 ENTRY(__hyp_stub_install_secondary) 82 mrs r4, cpsr 83 and r4, r4, #MODE_MASK 84 85 /* 86 * If the secondary has booted with a different mode, give up 87 * immediately. 88 */ 89 compare_cpu_mode_with_primary r4, r5, r6 90 retne lr 91 92 /* 93 * Once we have given up on one CPU, we do not try to install the 94 * stub hypervisor on the remaining ones: because the saved boot mode 95 * is modified, it can't compare equal to the CPSR mode field any 96 * more. 97 * 98 * Otherwise... 99 */ 100 101 cmp r4, #HYP_MODE 102 retne lr @ give up if the CPU is not in HYP mode 103 104 /* 105 * Configure HSCTLR to set correct exception endianness/instruction set 106 * state etc. 107 * Turn off all traps 108 * Eventually, CPU-specific code might be needed -- assume not for now 109 * 110 * This code relies on the "eret" instruction to synchronize the 111 * various coprocessor accesses. This is done when we switch to SVC 112 * (see safe_svcmode_maskall). 113 */ 114 @ Now install the hypervisor stub: 115 W(adr) r7, __hyp_stub_vectors 116 mcr p15, 4, r7, c12, c0, 0 @ set hypervisor vector base (HVBAR) 117 118 @ Disable all traps, so we don't get any nasty surprise 119 mov r7, #0 120 mcr p15, 4, r7, c1, c1, 0 @ HCR 121 mcr p15, 4, r7, c1, c1, 2 @ HCPTR 122 mcr p15, 4, r7, c1, c1, 3 @ HSTR 123 124 THUMB( orr r7, #(1 << 30) ) @ HSCTLR.TE 125 ARM_BE8(orr r7, r7, #(1 << 25)) @ HSCTLR.EE 126 mcr p15, 4, r7, c1, c0, 0 @ HSCTLR 127 128 mrc p15, 4, r7, c1, c1, 1 @ HDCR 129 and r7, #0x1f @ Preserve HPMN 130 mcr p15, 4, r7, c1, c1, 1 @ HDCR 131 132 @ Make sure NS-SVC is initialised appropriately 133 mrc p15, 0, r7, c1, c0, 0 @ SCTLR 134 orr r7, #(1 << 5) @ CP15 barriers enabled 135 bic r7, #(3 << 7) @ Clear SED/ITD for v8 (RES0 for v7) 136 bic r7, #(3 << 19) @ WXN and UWXN disabled 137 mcr p15, 0, r7, c1, c0, 0 @ SCTLR 138 139 mrc p15, 0, r7, c0, c0, 0 @ MIDR 140 mcr p15, 4, r7, c0, c0, 0 @ VPIDR 141 142 mrc p15, 0, r7, c0, c0, 5 @ MPIDR 143 mcr p15, 4, r7, c0, c0, 5 @ VMPIDR 144 145 #if !defined(ZIMAGE) && defined(CONFIG_ARM_ARCH_TIMER) 146 @ make CNTP_* and CNTPCT accessible from PL1 147 mrc p15, 0, r7, c0, c1, 1 @ ID_PFR1 148 ubfx r7, r7, #16, #4 149 teq r7, #0 150 beq 1f 151 mrc p15, 4, r7, c14, c1, 0 @ CNTHCTL 152 orr r7, r7, #3 @ PL1PCEN | PL1PCTEN 153 mcr p15, 4, r7, c14, c1, 0 @ CNTHCTL 154 mov r7, #0 155 mcrr p15, 4, r7, r7, c14 @ CNTVOFF 156 157 @ Disable virtual timer in case it was counting 158 mrc p15, 0, r7, c14, c3, 1 @ CNTV_CTL 159 bic r7, #1 @ Clear ENABLE 160 mcr p15, 0, r7, c14, c3, 1 @ CNTV_CTL 161 1: 162 #endif 163 164 #ifdef CONFIG_ARM_GIC_V3 165 @ Check whether GICv3 system registers are available 166 mrc p15, 0, r7, c0, c1, 1 @ ID_PFR1 167 ubfx r7, r7, #28, #4 168 teq r7, #0 169 beq 2f 170 171 @ Enable system register accesses 172 mrc p15, 4, r7, c12, c9, 5 @ ICC_HSRE 173 orr r7, r7, #(ICC_SRE_EL2_ENABLE | ICC_SRE_EL2_SRE) 174 mcr p15, 4, r7, c12, c9, 5 @ ICC_HSRE 175 isb 176 177 @ SRE bit could be forced to 0 by firmware. 178 @ Check whether it sticks before accessing any other sysreg 179 mrc p15, 4, r7, c12, c9, 5 @ ICC_HSRE 180 tst r7, #ICC_SRE_EL2_SRE 181 beq 2f 182 mov r7, #0 183 mcr p15, 4, r7, c12, c11, 0 @ ICH_HCR 184 2: 185 #endif 186 187 bx lr @ The boot CPU mode is left in r4. 188 ENDPROC(__hyp_stub_install_secondary) 189 190 __hyp_stub_do_trap: 191 #ifdef ZIMAGE 192 teq r0, #HVC_SET_VECTORS 193 bne 1f 194 /* Only the ZIMAGE stubs can change the HYP vectors */ 195 mcr p15, 4, r1, c12, c0, 0 @ set HVBAR 196 b __hyp_stub_exit 197 #endif 198 199 1: teq r0, #HVC_SOFT_RESTART 200 bne 2f 201 bx r1 202 203 2: ldr r0, =HVC_STUB_ERR 204 __ERET 205 206 __hyp_stub_exit: 207 mov r0, #0 208 __ERET 209 ENDPROC(__hyp_stub_do_trap) 210 211 /* 212 * __hyp_set_vectors is only used when ZIMAGE must bounce between HYP 213 * and SVC. For the kernel itself, the vectors are set once and for 214 * all by the stubs. 215 */ 216 ENTRY(__hyp_set_vectors) 217 mov r1, r0 218 mov r0, #HVC_SET_VECTORS 219 __HVC(0) 220 ret lr 221 ENDPROC(__hyp_set_vectors) 222 223 ENTRY(__hyp_soft_restart) 224 mov r1, r0 225 mov r0, #HVC_SOFT_RESTART 226 __HVC(0) 227 ret lr 228 ENDPROC(__hyp_soft_restart) 229 230 .align 5 231 ENTRY(__hyp_stub_vectors) 232 __hyp_stub_reset: W(b) . 233 __hyp_stub_und: W(b) . 234 __hyp_stub_svc: W(b) . 235 __hyp_stub_pabort: W(b) . 236 __hyp_stub_dabort: W(b) . 237 __hyp_stub_trap: W(b) __hyp_stub_do_trap 238 __hyp_stub_irq: W(b) . 239 __hyp_stub_fiq: W(b) . 240 ENDPROC(__hyp_stub_vectors) 241
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.