/*
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* Copyright (C) 2012 - Virtual Open Systems and Columbia University
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* Author: Christoffer Dall <c.dall@virtualopensystems.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License, version 2, as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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#include <linux/linkage.h>
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#include <asm/assembler.h>
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#include <asm/unified.h>
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#include <asm/asm-offsets.h>
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#include <asm/kvm_asm.h>
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#include <asm/kvm_arm.h>
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#include <asm/kvm_mmu.h>
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#include <asm/virt.h>
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/********************************************************************
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* Hypervisor initialization
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* - should be called with:
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* r0 = top of Hyp stack (kernel VA)
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* r1 = pointer to hyp vectors
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* r2,r3 = Hypervisor pgd pointer
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*
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* The init scenario is:
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* - We jump in HYP with 3 parameters: runtime HYP pgd, runtime stack,
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* runtime vectors
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* - Invalidate TLBs
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* - Set stack and vectors
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* - Setup the page tables
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* - Enable the MMU
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* - Profit! (or eret, if you only care about the code).
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*
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* Another possibility is to get a HYP stub hypercall.
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* We discriminate between the two by checking if r0 contains a value
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* that is less than HVC_STUB_HCALL_NR.
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*/
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.text
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.pushsection .hyp.idmap.text,"ax"
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.align 5
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__kvm_hyp_init:
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.globl __kvm_hyp_init
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@ Hyp-mode exception vector
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W(b) .
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W(b) .
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W(b) .
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W(b) .
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W(b) .
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W(b) __do_hyp_init
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W(b) .
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W(b) .
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__do_hyp_init:
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@ Check for a stub hypercall
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cmp r0, #HVC_STUB_HCALL_NR
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blo __kvm_handle_stub_hvc
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@ Set stack pointer
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mov sp, r0
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@ Set HVBAR to point to the HYP vectors
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mcr p15, 4, r1, c12, c0, 0 @ HVBAR
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@ Set the HTTBR to point to the hypervisor PGD pointer passed
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mcrr p15, 4, rr_lo_hi(r2, r3), c2
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@ Set the HTCR and VTCR to the same shareability and cacheability
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@ settings as the non-secure TTBCR and with T0SZ == 0.
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mrc p15, 4, r0, c2, c0, 2 @ HTCR
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ldr r2, =HTCR_MASK
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bic r0, r0, r2
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mrc p15, 0, r1, c2, c0, 2 @ TTBCR
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and r1, r1, #(HTCR_MASK & ~TTBCR_T0SZ)
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orr r0, r0, r1
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mcr p15, 4, r0, c2, c0, 2 @ HTCR
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@ Use the same memory attributes for hyp. accesses as the kernel
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@ (copy MAIRx ro HMAIRx).
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mrc p15, 0, r0, c10, c2, 0
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mcr p15, 4, r0, c10, c2, 0
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mrc p15, 0, r0, c10, c2, 1
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mcr p15, 4, r0, c10, c2, 1
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@ Invalidate the stale TLBs from Bootloader
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mcr p15, 4, r0, c8, c7, 0 @ TLBIALLH
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dsb ish
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@ Set the HSCTLR to:
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@ - ARM/THUMB exceptions: Kernel config (Thumb-2 kernel)
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@ - Endianness: Kernel config
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@ - Fast Interrupt Features: Kernel config
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@ - Write permission implies XN: disabled
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@ - Instruction cache: enabled
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@ - Data/Unified cache: enabled
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@ - MMU: enabled (this code must be run from an identity mapping)
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mrc p15, 4, r0, c1, c0, 0 @ HSCR
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ldr r2, =HSCTLR_MASK
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bic r0, r0, r2
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mrc p15, 0, r1, c1, c0, 0 @ SCTLR
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ldr r2, =(HSCTLR_EE | HSCTLR_FI | HSCTLR_I | HSCTLR_C)
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and r1, r1, r2
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ARM( ldr r2, =(HSCTLR_M) )
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THUMB( ldr r2, =(HSCTLR_M | HSCTLR_TE) )
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orr r1, r1, r2
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orr r0, r0, r1
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mcr p15, 4, r0, c1, c0, 0 @ HSCR
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isb
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eret
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ENTRY(__kvm_handle_stub_hvc)
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cmp r0, #HVC_SOFT_RESTART
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bne 1f
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/* The target is expected in r1 */
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msr ELR_hyp, r1
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mrs r0, cpsr
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bic r0, r0, #MODE_MASK
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orr r0, r0, #HYP_MODE
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THUMB( orr r0, r0, #PSR_T_BIT )
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msr spsr_cxsf, r0
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b reset
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1: cmp r0, #HVC_RESET_VECTORS
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bne 1f
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reset:
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/* We're now in idmap, disable MMU */
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mrc p15, 4, r1, c1, c0, 0 @ HSCTLR
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ldr r0, =(HSCTLR_M | HSCTLR_A | HSCTLR_C | HSCTLR_I)
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bic r1, r1, r0
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mcr p15, 4, r1, c1, c0, 0 @ HSCTLR
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/*
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* Install stub vectors, using ardb's VA->PA trick.
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*/
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0: adr r0, 0b @ PA(0)
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movw r1, #:lower16:__hyp_stub_vectors - 0b @ VA(stub) - VA(0)
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movt r1, #:upper16:__hyp_stub_vectors - 0b
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add r1, r1, r0 @ PA(stub)
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mcr p15, 4, r1, c12, c0, 0 @ HVBAR
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b exit
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1: ldr r0, =HVC_STUB_ERR
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eret
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exit:
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mov r0, #0
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eret
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ENDPROC(__kvm_handle_stub_hvc)
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.ltorg
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.globl __kvm_hyp_init_end
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__kvm_hyp_init_end:
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.popsection
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