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d5e528136c
Linux contains quite some bits of code to load FPU, Altivec and VSX lazily for a task. It calls those bits in real mode, coming from an interrupt handler. For KVM we better reuse those, so let's wrap a bit of trampoline magic around them and then we can call them from normal module code. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
205 lines
5.2 KiB
ArmAsm
205 lines
5.2 KiB
ArmAsm
/*
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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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* Copyright SUSE Linux Products GmbH 2009
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*
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* Authors: Alexander Graf <agraf@suse.de>
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*/
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#include <asm/ppc_asm.h>
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#include <asm/kvm_asm.h>
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#include <asm/reg.h>
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#include <asm/page.h>
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#include <asm/asm-offsets.h>
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#include <asm/exception-64s.h>
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/*****************************************************************************
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* *
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* Real Mode handlers that need to be in low physical memory *
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* *
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****************************************************************************/
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.macro INTERRUPT_TRAMPOLINE intno
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.global kvmppc_trampoline_\intno
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kvmppc_trampoline_\intno:
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mtspr SPRN_SPRG_SCRATCH0, r13 /* Save r13 */
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/*
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* First thing to do is to find out if we're coming
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* from a KVM guest or a Linux process.
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*
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* To distinguish, we check a magic byte in the PACA
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*/
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mfspr r13, SPRN_SPRG_PACA /* r13 = PACA */
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std r12, PACA_KVM_SCRATCH0(r13)
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mfcr r12
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stw r12, PACA_KVM_SCRATCH1(r13)
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lbz r12, PACA_KVM_IN_GUEST(r13)
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cmpwi r12, KVM_GUEST_MODE_NONE
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bne ..kvmppc_handler_hasmagic_\intno
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/* No KVM guest? Then jump back to the Linux handler! */
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lwz r12, PACA_KVM_SCRATCH1(r13)
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mtcr r12
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ld r12, PACA_KVM_SCRATCH0(r13)
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mfspr r13, SPRN_SPRG_SCRATCH0 /* r13 = original r13 */
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b kvmppc_resume_\intno /* Get back original handler */
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/* Now we know we're handling a KVM guest */
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..kvmppc_handler_hasmagic_\intno:
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/* Should we just skip the faulting instruction? */
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cmpwi r12, KVM_GUEST_MODE_SKIP
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beq kvmppc_handler_skip_ins
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/* Let's store which interrupt we're handling */
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li r12, \intno
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/* Jump into the SLB exit code that goes to the highmem handler */
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b kvmppc_handler_trampoline_exit
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.endm
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_SYSTEM_RESET
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_MACHINE_CHECK
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_DATA_STORAGE
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_DATA_SEGMENT
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_INST_STORAGE
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_INST_SEGMENT
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_EXTERNAL
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_ALIGNMENT
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_PROGRAM
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_FP_UNAVAIL
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_DECREMENTER
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_SYSCALL
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_TRACE
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_PERFMON
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_ALTIVEC
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_VSX
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/*
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* Bring us back to the faulting code, but skip the
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* faulting instruction.
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*
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* This is a generic exit path from the interrupt
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* trampolines above.
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*
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* Input Registers:
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*
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* R12 = free
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* R13 = PACA
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* PACA.KVM.SCRATCH0 = guest R12
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* PACA.KVM.SCRATCH1 = guest CR
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* SPRG_SCRATCH0 = guest R13
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*
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*/
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kvmppc_handler_skip_ins:
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/* Patch the IP to the next instruction */
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mfsrr0 r12
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addi r12, r12, 4
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mtsrr0 r12
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/* Clean up all state */
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lwz r12, PACA_KVM_SCRATCH1(r13)
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mtcr r12
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ld r12, PACA_KVM_SCRATCH0(r13)
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mfspr r13, SPRN_SPRG_SCRATCH0
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/* And get back into the code */
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RFI
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/*
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* This trampoline brings us back to a real mode handler
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*
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* Input Registers:
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*
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* R5 = SRR0
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* R6 = SRR1
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* LR = real-mode IP
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*
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*/
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.global kvmppc_handler_lowmem_trampoline
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kvmppc_handler_lowmem_trampoline:
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mtsrr0 r5
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mtsrr1 r6
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blr
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kvmppc_handler_lowmem_trampoline_end:
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/*
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* Call a function in real mode
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*
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* Input Registers:
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*
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* R3 = function
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* R4 = MSR
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* R5 = CTR
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*
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*/
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_GLOBAL(kvmppc_rmcall)
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mtmsr r4 /* Disable relocation, so mtsrr
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doesn't get interrupted */
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mtctr r5
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mtsrr0 r3
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mtsrr1 r4
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RFI
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/*
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* Activate current's external feature (FPU/Altivec/VSX)
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*/
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#define define_load_up(what) \
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\
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_GLOBAL(kvmppc_load_up_ ## what); \
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subi r1, r1, INT_FRAME_SIZE; \
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mflr r3; \
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std r3, _LINK(r1); \
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mfmsr r4; \
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std r31, GPR3(r1); \
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mr r31, r4; \
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li r5, MSR_DR; \
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oris r5, r5, MSR_EE@h; \
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andc r4, r4, r5; \
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mtmsr r4; \
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\
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bl .load_up_ ## what; \
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\
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mtmsr r31; \
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ld r3, _LINK(r1); \
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ld r31, GPR3(r1); \
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addi r1, r1, INT_FRAME_SIZE; \
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mtlr r3; \
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blr
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define_load_up(fpu)
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#ifdef CONFIG_ALTIVEC
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define_load_up(altivec)
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#endif
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#ifdef CONFIG_VSX
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define_load_up(vsx)
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#endif
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.global kvmppc_trampoline_lowmem
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kvmppc_trampoline_lowmem:
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.long kvmppc_handler_lowmem_trampoline - _stext
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.global kvmppc_trampoline_enter
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kvmppc_trampoline_enter:
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.long kvmppc_handler_trampoline_enter - _stext
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#include "book3s_64_slb.S"
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