v4.19.13 snapshot.
diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S
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+/*
+ * Copyright (c) 2012 Linaro Limited.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <linux/init.h>
+#include <linux/irqchip/arm-gic-v3.h>
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/virt.h>
+
+#ifndef ZIMAGE
+/*
+ * For the kernel proper, we need to find out the CPU boot mode long after
+ * boot, so we need to store it in a writable variable.
+ *
+ * This is not in .bss, because we set it sufficiently early that the boot-time
+ * zeroing of .bss would clobber it.
+ */
+.data
+ .align 2
+ENTRY(__boot_cpu_mode)
+ .long 0
+.text
+
+ /*
+ * Save the primary CPU boot mode. Requires 3 scratch registers.
+ */
+ .macro store_primary_cpu_mode reg1, reg2, reg3
+ mrs \reg1, cpsr
+ and \reg1, \reg1, #MODE_MASK
+ adr \reg2, .L__boot_cpu_mode_offset
+ ldr \reg3, [\reg2]
+ str \reg1, [\reg2, \reg3]
+ .endm
+
+ /*
+ * Compare the current mode with the one saved on the primary CPU.
+ * If they don't match, record that fact. The Z bit indicates
+ * if there's a match or not.
+ * Requires 3 additionnal scratch registers.
+ */
+ .macro compare_cpu_mode_with_primary mode, reg1, reg2, reg3
+ adr \reg2, .L__boot_cpu_mode_offset
+ ldr \reg3, [\reg2]
+ ldr \reg1, [\reg2, \reg3]
+ cmp \mode, \reg1 @ matches primary CPU boot mode?
+ orrne \reg1, \reg1, #BOOT_CPU_MODE_MISMATCH
+ strne \reg1, [\reg2, \reg3] @ record what happened and give up
+ .endm
+
+#else /* ZIMAGE */
+
+ .macro store_primary_cpu_mode reg1:req, reg2:req, reg3:req
+ .endm
+
+/*
+ * The zImage loader only runs on one CPU, so we don't bother with mult-CPU
+ * consistency checking:
+ */
+ .macro compare_cpu_mode_with_primary mode, reg1, reg2, reg3
+ cmp \mode, \mode
+ .endm
+
+#endif /* ZIMAGE */
+
+/*
+ * Hypervisor stub installation functions.
+ *
+ * These must be called with the MMU and D-cache off.
+ * They are not ABI compliant and are only intended to be called from the kernel
+ * entry points in head.S.
+ */
+@ Call this from the primary CPU
+ENTRY(__hyp_stub_install)
+ store_primary_cpu_mode r4, r5, r6
+ENDPROC(__hyp_stub_install)
+
+ @ fall through...
+
+@ Secondary CPUs should call here
+ENTRY(__hyp_stub_install_secondary)
+ mrs r4, cpsr
+ and r4, r4, #MODE_MASK
+
+ /*
+ * If the secondary has booted with a different mode, give up
+ * immediately.
+ */
+ compare_cpu_mode_with_primary r4, r5, r6, r7
+ retne lr
+
+ /*
+ * Once we have given up on one CPU, we do not try to install the
+ * stub hypervisor on the remaining ones: because the saved boot mode
+ * is modified, it can't compare equal to the CPSR mode field any
+ * more.
+ *
+ * Otherwise...
+ */
+
+ cmp r4, #HYP_MODE
+ retne lr @ give up if the CPU is not in HYP mode
+
+/*
+ * Configure HSCTLR to set correct exception endianness/instruction set
+ * state etc.
+ * Turn off all traps
+ * Eventually, CPU-specific code might be needed -- assume not for now
+ *
+ * This code relies on the "eret" instruction to synchronize the
+ * various coprocessor accesses. This is done when we switch to SVC
+ * (see safe_svcmode_maskall).
+ */
+ @ Now install the hypervisor stub:
+ W(adr) r7, __hyp_stub_vectors
+ mcr p15, 4, r7, c12, c0, 0 @ set hypervisor vector base (HVBAR)
+
+ @ Disable all traps, so we don't get any nasty surprise
+ mov r7, #0
+ mcr p15, 4, r7, c1, c1, 0 @ HCR
+ mcr p15, 4, r7, c1, c1, 2 @ HCPTR
+ mcr p15, 4, r7, c1, c1, 3 @ HSTR
+
+THUMB( orr r7, #(1 << 30) ) @ HSCTLR.TE
+ARM_BE8(orr r7, r7, #(1 << 25)) @ HSCTLR.EE
+ mcr p15, 4, r7, c1, c0, 0 @ HSCTLR
+
+ mrc p15, 4, r7, c1, c1, 1 @ HDCR
+ and r7, #0x1f @ Preserve HPMN
+ mcr p15, 4, r7, c1, c1, 1 @ HDCR
+
+ @ Make sure NS-SVC is initialised appropriately
+ mrc p15, 0, r7, c1, c0, 0 @ SCTLR
+ orr r7, #(1 << 5) @ CP15 barriers enabled
+ bic r7, #(3 << 7) @ Clear SED/ITD for v8 (RES0 for v7)
+ bic r7, #(3 << 19) @ WXN and UWXN disabled
+ mcr p15, 0, r7, c1, c0, 0 @ SCTLR
+
+ mrc p15, 0, r7, c0, c0, 0 @ MIDR
+ mcr p15, 4, r7, c0, c0, 0 @ VPIDR
+
+ mrc p15, 0, r7, c0, c0, 5 @ MPIDR
+ mcr p15, 4, r7, c0, c0, 5 @ VMPIDR
+
+#if !defined(ZIMAGE) && defined(CONFIG_ARM_ARCH_TIMER)
+ @ make CNTP_* and CNTPCT accessible from PL1
+ mrc p15, 0, r7, c0, c1, 1 @ ID_PFR1
+ lsr r7, #16
+ and r7, #0xf
+ cmp r7, #1
+ bne 1f
+ mrc p15, 4, r7, c14, c1, 0 @ CNTHCTL
+ orr r7, r7, #3 @ PL1PCEN | PL1PCTEN
+ mcr p15, 4, r7, c14, c1, 0 @ CNTHCTL
+ mov r7, #0
+ mcrr p15, 4, r7, r7, c14 @ CNTVOFF
+
+ @ Disable virtual timer in case it was counting
+ mrc p15, 0, r7, c14, c3, 1 @ CNTV_CTL
+ bic r7, #1 @ Clear ENABLE
+ mcr p15, 0, r7, c14, c3, 1 @ CNTV_CTL
+1:
+#endif
+
+#ifdef CONFIG_ARM_GIC_V3
+ @ Check whether GICv3 system registers are available
+ mrc p15, 0, r7, c0, c1, 1 @ ID_PFR1
+ ubfx r7, r7, #28, #4
+ cmp r7, #1
+ bne 2f
+
+ @ Enable system register accesses
+ mrc p15, 4, r7, c12, c9, 5 @ ICC_HSRE
+ orr r7, r7, #(ICC_SRE_EL2_ENABLE | ICC_SRE_EL2_SRE)
+ mcr p15, 4, r7, c12, c9, 5 @ ICC_HSRE
+ isb
+
+ @ SRE bit could be forced to 0 by firmware.
+ @ Check whether it sticks before accessing any other sysreg
+ mrc p15, 4, r7, c12, c9, 5 @ ICC_HSRE
+ tst r7, #ICC_SRE_EL2_SRE
+ beq 2f
+ mov r7, #0
+ mcr p15, 4, r7, c12, c11, 0 @ ICH_HCR
+2:
+#endif
+
+ bx lr @ The boot CPU mode is left in r4.
+ENDPROC(__hyp_stub_install_secondary)
+
+__hyp_stub_do_trap:
+ teq r0, #HVC_SET_VECTORS
+ bne 1f
+ mcr p15, 4, r1, c12, c0, 0 @ set HVBAR
+ b __hyp_stub_exit
+
+1: teq r0, #HVC_SOFT_RESTART
+ bne 1f
+ bx r1
+
+1: teq r0, #HVC_RESET_VECTORS
+ beq __hyp_stub_exit
+
+ ldr r0, =HVC_STUB_ERR
+ __ERET
+
+__hyp_stub_exit:
+ mov r0, #0
+ __ERET
+ENDPROC(__hyp_stub_do_trap)
+
+/*
+ * __hyp_set_vectors: Call this after boot to set the initial hypervisor
+ * vectors as part of hypervisor installation. On an SMP system, this should
+ * be called on each CPU.
+ *
+ * r0 must be the physical address of the new vector table (which must lie in
+ * the bottom 4GB of physical address space.
+ *
+ * r0 must be 32-byte aligned.
+ *
+ * Before calling this, you must check that the stub hypervisor is installed
+ * everywhere, by waiting for any secondary CPUs to be brought up and then
+ * checking that BOOT_CPU_MODE_HAVE_HYP(__boot_cpu_mode) is true.
+ *
+ * If not, there is a pre-existing hypervisor, some CPUs failed to boot, or
+ * something else went wrong... in such cases, trying to install a new
+ * hypervisor is unlikely to work as desired.
+ *
+ * When you call into your shiny new hypervisor, sp_hyp will contain junk,
+ * so you will need to set that to something sensible at the new hypervisor's
+ * initialisation entry point.
+ */
+ENTRY(__hyp_set_vectors)
+ mov r1, r0
+ mov r0, #HVC_SET_VECTORS
+ __HVC(0)
+ ret lr
+ENDPROC(__hyp_set_vectors)
+
+ENTRY(__hyp_soft_restart)
+ mov r1, r0
+ mov r0, #HVC_SOFT_RESTART
+ __HVC(0)
+ ret lr
+ENDPROC(__hyp_soft_restart)
+
+ENTRY(__hyp_reset_vectors)
+ mov r0, #HVC_RESET_VECTORS
+ __HVC(0)
+ ret lr
+ENDPROC(__hyp_reset_vectors)
+
+#ifndef ZIMAGE
+.align 2
+.L__boot_cpu_mode_offset:
+ .long __boot_cpu_mode - .
+#endif
+
+.align 5
+ENTRY(__hyp_stub_vectors)
+__hyp_stub_reset: W(b) .
+__hyp_stub_und: W(b) .
+__hyp_stub_svc: W(b) .
+__hyp_stub_pabort: W(b) .
+__hyp_stub_dabort: W(b) .
+__hyp_stub_trap: W(b) __hyp_stub_do_trap
+__hyp_stub_irq: W(b) .
+__hyp_stub_fiq: W(b) .
+ENDPROC(__hyp_stub_vectors)
+