forked from mirrors/linux
33b5c38852
We currently have the HSCTLR.A bit set, trapping unaligned accesses at HYP, but we're not really prepared to deal with it. Since the rest of the kernel is pretty happy about that, let's follow its example and set HSCTLR.A to zero. Modern CPUs don't really care. Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
169 lines
4.3 KiB
ArmAsm
169 lines
4.3 KiB
ArmAsm
/*
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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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