67870eb120
In banked-sr.c, we use a top-level '__asm__(".arch_extension virt")'
statement to allow compilation of a multi-CPU kernel for ARMv6
and older ARMv7-A that don't normally support access to the banked
registers.
This is considered to be a programming error by the gcc developers
and will no longer work in gcc-8, where we now get a build error:
/tmp/cc4Qy7GR.s:34: Error: Banked registers are not available with this architecture. -- `mrs r3,SP_usr'
/tmp/cc4Qy7GR.s:41: Error: Banked registers are not available with this architecture. -- `mrs r3,ELR_hyp'
/tmp/cc4Qy7GR.s:55: Error: Banked registers are not available with this architecture. -- `mrs r3,SP_svc'
/tmp/cc4Qy7GR.s:62: Error: Banked registers are not available with this architecture. -- `mrs r3,LR_svc'
/tmp/cc4Qy7GR.s:69: Error: Banked registers are not available with this architecture. -- `mrs r3,SPSR_svc'
/tmp/cc4Qy7GR.s:76: Error: Banked registers are not available with this architecture. -- `mrs r3,SP_abt'
Passign the '-march-armv7ve' flag to gcc works, and is ok here, because
we know the functions won't ever be called on pre-ARMv7VE machines.
Unfortunately, older compiler versions (4.8 and earlier) do not understand
that flag, so we still need to keep the asm around.
Backporting to stable kernels (4.6+) is needed to allow those to be built
with future compilers as well.
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84129
Fixes: 33280b4cd1 ("ARM: KVM: Add banked registers save/restore")
Cc: stable@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
82 lines
3.6 KiB
C
82 lines
3.6 KiB
C
/*
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* Original code:
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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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* Mostly rewritten in C by Marc Zyngier <marc.zyngier@arm.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, see <http://www.gnu.org/licenses/>.
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*/
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#include <asm/kvm_hyp.h>
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/*
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* gcc before 4.9 doesn't understand -march=armv7ve, so we have to
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* trick the assembler.
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*/
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__asm__(".arch_extension virt");
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void __hyp_text __banked_save_state(struct kvm_cpu_context *ctxt)
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{
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ctxt->gp_regs.usr_regs.ARM_sp = read_special(SP_usr);
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ctxt->gp_regs.usr_regs.ARM_pc = read_special(ELR_hyp);
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ctxt->gp_regs.usr_regs.ARM_cpsr = read_special(SPSR);
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ctxt->gp_regs.KVM_ARM_SVC_sp = read_special(SP_svc);
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ctxt->gp_regs.KVM_ARM_SVC_lr = read_special(LR_svc);
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ctxt->gp_regs.KVM_ARM_SVC_spsr = read_special(SPSR_svc);
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ctxt->gp_regs.KVM_ARM_ABT_sp = read_special(SP_abt);
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ctxt->gp_regs.KVM_ARM_ABT_lr = read_special(LR_abt);
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ctxt->gp_regs.KVM_ARM_ABT_spsr = read_special(SPSR_abt);
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ctxt->gp_regs.KVM_ARM_UND_sp = read_special(SP_und);
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ctxt->gp_regs.KVM_ARM_UND_lr = read_special(LR_und);
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ctxt->gp_regs.KVM_ARM_UND_spsr = read_special(SPSR_und);
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ctxt->gp_regs.KVM_ARM_IRQ_sp = read_special(SP_irq);
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ctxt->gp_regs.KVM_ARM_IRQ_lr = read_special(LR_irq);
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ctxt->gp_regs.KVM_ARM_IRQ_spsr = read_special(SPSR_irq);
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ctxt->gp_regs.KVM_ARM_FIQ_r8 = read_special(R8_fiq);
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ctxt->gp_regs.KVM_ARM_FIQ_r9 = read_special(R9_fiq);
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ctxt->gp_regs.KVM_ARM_FIQ_r10 = read_special(R10_fiq);
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ctxt->gp_regs.KVM_ARM_FIQ_fp = read_special(R11_fiq);
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ctxt->gp_regs.KVM_ARM_FIQ_ip = read_special(R12_fiq);
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ctxt->gp_regs.KVM_ARM_FIQ_sp = read_special(SP_fiq);
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ctxt->gp_regs.KVM_ARM_FIQ_lr = read_special(LR_fiq);
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ctxt->gp_regs.KVM_ARM_FIQ_spsr = read_special(SPSR_fiq);
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}
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void __hyp_text __banked_restore_state(struct kvm_cpu_context *ctxt)
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{
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write_special(ctxt->gp_regs.usr_regs.ARM_sp, SP_usr);
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write_special(ctxt->gp_regs.usr_regs.ARM_pc, ELR_hyp);
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write_special(ctxt->gp_regs.usr_regs.ARM_cpsr, SPSR_cxsf);
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write_special(ctxt->gp_regs.KVM_ARM_SVC_sp, SP_svc);
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write_special(ctxt->gp_regs.KVM_ARM_SVC_lr, LR_svc);
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write_special(ctxt->gp_regs.KVM_ARM_SVC_spsr, SPSR_svc);
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write_special(ctxt->gp_regs.KVM_ARM_ABT_sp, SP_abt);
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write_special(ctxt->gp_regs.KVM_ARM_ABT_lr, LR_abt);
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write_special(ctxt->gp_regs.KVM_ARM_ABT_spsr, SPSR_abt);
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write_special(ctxt->gp_regs.KVM_ARM_UND_sp, SP_und);
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write_special(ctxt->gp_regs.KVM_ARM_UND_lr, LR_und);
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write_special(ctxt->gp_regs.KVM_ARM_UND_spsr, SPSR_und);
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write_special(ctxt->gp_regs.KVM_ARM_IRQ_sp, SP_irq);
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write_special(ctxt->gp_regs.KVM_ARM_IRQ_lr, LR_irq);
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write_special(ctxt->gp_regs.KVM_ARM_IRQ_spsr, SPSR_irq);
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write_special(ctxt->gp_regs.KVM_ARM_FIQ_r8, R8_fiq);
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write_special(ctxt->gp_regs.KVM_ARM_FIQ_r9, R9_fiq);
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write_special(ctxt->gp_regs.KVM_ARM_FIQ_r10, R10_fiq);
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write_special(ctxt->gp_regs.KVM_ARM_FIQ_fp, R11_fiq);
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write_special(ctxt->gp_regs.KVM_ARM_FIQ_ip, R12_fiq);
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write_special(ctxt->gp_regs.KVM_ARM_FIQ_sp, SP_fiq);
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write_special(ctxt->gp_regs.KVM_ARM_FIQ_lr, LR_fiq);
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write_special(ctxt->gp_regs.KVM_ARM_FIQ_spsr, SPSR_fiq);
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}
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