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/*
* Copyright (C) 2012 - Virtual Open Systems and Columbia University
* Author: Christoffer Dall <c.dall@virtualopensystems.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* 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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/unified.h>
#include <asm/asm-offsets.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_mmu.h>
/********************************************************************
* Hypervisor initialization
* - should be called with:
* r0 = top of Hyp stack (kernel VA)
* r1 = pointer to hyp vectors
* r2,r3 = Hypervisor pgd pointer
*
* The init scenario is:
* - We jump in HYP with four parameters: boot HYP pgd, runtime HYP pgd,
* runtime stack, runtime vectors
* - Enable the MMU with the boot pgd
* - Jump to a target into the trampoline page (remember, this is the same
* physical page!)
* - Now switch to the runtime pgd (same VA, and still the same physical
* page!)
* - Invalidate TLBs
* - Set stack and vectors
* - Profit! (or eret, if you only care about the code).
*
* As we only have four registers available to pass parameters (and we
* need six), we split the init in two phases:
* - Phase 1: r0 = 0, r1 = 0, r2,r3 contain the boot PGD.
* Provides the basic HYP init, and enable the MMU.
* - Phase 2: r0 = ToS, r1 = vectors, r2,r3 contain the runtime PGD.
* Switches to the runtime PGD, set stack and vectors.
*/
.text
.pushsection .hyp.idmap.text,"ax"
.align 5
__kvm_hyp_init:
.globl __kvm_hyp_init
@ Hyp-mode exception vector
W(b) .
W(b) .
W(b) .
W(b) .
W(b) .
W(b) __do_hyp_init
W(b) .
W(b) .
__do_hyp_init:
cmp r0, #0 @ We have a SP?
bne phase2 @ Yes, second stage init
@ Set the HTTBR to point to the hypervisor PGD pointer passed
mcrr p15, 4, rr_lo_hi(r2, r3), c2
@ Set the HTCR and VTCR to the same shareability and cacheability
@ settings as the non-secure TTBCR and with T0SZ == 0.
mrc p15, 4, r0, c2, c0, 2 @ HTCR
ldr r2, =HTCR_MASK
bic r0, r0, r2
mrc p15, 0, r1, c2, c0, 2 @ TTBCR
and r1, r1, #(HTCR_MASK & ~TTBCR_T0SZ)
orr r0, r0, r1
mcr p15, 4, r0, c2, c0, 2 @ HTCR
@ Use the same memory attributes for hyp. accesses as the kernel
@ (copy MAIRx ro HMAIRx).
mrc p15, 0, r0, c10, c2, 0
mcr p15, 4, r0, c10, c2, 0
mrc p15, 0, r0, c10, c2, 1
mcr p15, 4, r0, c10, c2, 1
@ Invalidate the stale TLBs from Bootloader
mcr p15, 4, r0, c8, c7, 0 @ TLBIALLH
dsb ish
@ Set the HSCTLR to:
@ - ARM/THUMB exceptions: Kernel config (Thumb-2 kernel)
@ - Endianness: Kernel config
@ - Fast Interrupt Features: Kernel config
@ - Write permission implies XN: disabled
@ - Instruction cache: enabled
@ - Data/Unified cache: enabled
@ - Memory alignment checks: enabled
@ - MMU: enabled (this code must be run from an identity mapping)
mrc p15, 4, r0, c1, c0, 0 @ HSCR
ldr r2, =HSCTLR_MASK
bic r0, r0, r2
mrc p15, 0, r1, c1, c0, 0 @ SCTLR
ldr r2, =(HSCTLR_EE | HSCTLR_FI | HSCTLR_I | HSCTLR_C)
and r1, r1, r2
ARM( ldr r2, =(HSCTLR_M | HSCTLR_A) )
THUMB( ldr r2, =(HSCTLR_M | HSCTLR_A | HSCTLR_TE) )
orr r1, r1, r2
orr r0, r0, r1
isb
mcr p15, 4, r0, c1, c0, 0 @ HSCR
@ End of init phase-1
eret
phase2:
@ Set stack pointer
mov sp, r0
@ Set HVBAR to point to the HYP vectors
mcr p15, 4, r1, c12, c0, 0 @ HVBAR
@ Jump to the trampoline page
ldr r0, =TRAMPOLINE_VA
adr r1, target
bfi r0, r1, #0, #PAGE_SHIFT
ret r0
target: @ We're now in the trampoline code, switch page tables
mcrr p15, 4, rr_lo_hi(r2, r3), c2
isb
@ Invalidate the old TLBs
mcr p15, 4, r0, c8, c7, 0 @ TLBIALLH
dsb ish
eret
.ltorg
.globl __kvm_hyp_init_end
__kvm_hyp_init_end:
.popsection
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