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linux-pinenote/arch/arm/kvm/interrupts_head.S
Marc Zyngier c7e3ba64ba ARM: KVM: arch_timers: Add timer world switch 
Do the necessary save/restore dance for the timers in the world
switch code. In the process, allow the guest to read the physical
counter, which is useful for its own clock_event_device.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-02-11 19:05:38 +00:00

605 lines
14 KiB
ArmAsm
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#include <linux/irqchip/arm-gic.h>
#define VCPU_USR_REG(_reg_nr) (VCPU_USR_REGS + (_reg_nr * 4))
#define VCPU_USR_SP (VCPU_USR_REG(13))
#define VCPU_USR_LR (VCPU_USR_REG(14))
#define CP15_OFFSET(_cp15_reg_idx) (VCPU_CP15 + (_cp15_reg_idx * 4))
/*
* Many of these macros need to access the VCPU structure, which is always
* held in r0. These macros should never clobber r1, as it is used to hold the
* exception code on the return path (except of course the macro that switches
* all the registers before the final jump to the VM).
*/
vcpu .req r0 @ vcpu pointer always in r0
/* Clobbers {r2-r6} */
.macro store_vfp_state vfp_base
@ The VFPFMRX and VFPFMXR macros are the VMRS and VMSR instructions
VFPFMRX r2, FPEXC
@ Make sure VFP is enabled so we can touch the registers.
orr r6, r2, #FPEXC_EN
VFPFMXR FPEXC, r6
VFPFMRX r3, FPSCR
tst r2, #FPEXC_EX @ Check for VFP Subarchitecture
beq 1f
@ If FPEXC_EX is 0, then FPINST/FPINST2 reads are upredictable, so
@ we only need to save them if FPEXC_EX is set.
VFPFMRX r4, FPINST
tst r2, #FPEXC_FP2V
VFPFMRX r5, FPINST2, ne @ vmrsne
bic r6, r2, #FPEXC_EX @ FPEXC_EX disable
VFPFMXR FPEXC, r6
1:
VFPFSTMIA \vfp_base, r6 @ Save VFP registers
stm \vfp_base, {r2-r5} @ Save FPEXC, FPSCR, FPINST, FPINST2
.endm
/* Assume FPEXC_EN is on and FPEXC_EX is off, clobbers {r2-r6} */
.macro restore_vfp_state vfp_base
VFPFLDMIA \vfp_base, r6 @ Load VFP registers
ldm \vfp_base, {r2-r5} @ Load FPEXC, FPSCR, FPINST, FPINST2
VFPFMXR FPSCR, r3
tst r2, #FPEXC_EX @ Check for VFP Subarchitecture
beq 1f
VFPFMXR FPINST, r4
tst r2, #FPEXC_FP2V
VFPFMXR FPINST2, r5, ne
1:
VFPFMXR FPEXC, r2 @ FPEXC (last, in case !EN)
.endm
/* These are simply for the macros to work - value don't have meaning */
.equ usr, 0
.equ svc, 1
.equ abt, 2
.equ und, 3
.equ irq, 4
.equ fiq, 5
.macro push_host_regs_mode mode
mrs r2, SP_\mode
mrs r3, LR_\mode
mrs r4, SPSR_\mode
push {r2, r3, r4}
.endm
/*
* Store all host persistent registers on the stack.
* Clobbers all registers, in all modes, except r0 and r1.
*/
.macro save_host_regs
/* Hyp regs. Only ELR_hyp (SPSR_hyp already saved) */
mrs r2, ELR_hyp
push {r2}
/* usr regs */
push {r4-r12} @ r0-r3 are always clobbered
mrs r2, SP_usr
mov r3, lr
push {r2, r3}
push_host_regs_mode svc
push_host_regs_mode abt
push_host_regs_mode und
push_host_regs_mode irq
/* fiq regs */
mrs r2, r8_fiq
mrs r3, r9_fiq
mrs r4, r10_fiq
mrs r5, r11_fiq
mrs r6, r12_fiq
mrs r7, SP_fiq
mrs r8, LR_fiq
mrs r9, SPSR_fiq
push {r2-r9}
.endm
.macro pop_host_regs_mode mode
pop {r2, r3, r4}
msr SP_\mode, r2
msr LR_\mode, r3
msr SPSR_\mode, r4
.endm
/*
* Restore all host registers from the stack.
* Clobbers all registers, in all modes, except r0 and r1.
*/
.macro restore_host_regs
pop {r2-r9}
msr r8_fiq, r2
msr r9_fiq, r3
msr r10_fiq, r4
msr r11_fiq, r5
msr r12_fiq, r6
msr SP_fiq, r7
msr LR_fiq, r8
msr SPSR_fiq, r9
pop_host_regs_mode irq
pop_host_regs_mode und
pop_host_regs_mode abt
pop_host_regs_mode svc
pop {r2, r3}
msr SP_usr, r2
mov lr, r3
pop {r4-r12}
pop {r2}
msr ELR_hyp, r2
.endm
/*
* Restore SP, LR and SPSR for a given mode. offset is the offset of
* this mode's registers from the VCPU base.
*
* Assumes vcpu pointer in vcpu reg
*
* Clobbers r1, r2, r3, r4.
*/
.macro restore_guest_regs_mode mode, offset
add r1, vcpu, \offset
ldm r1, {r2, r3, r4}
msr SP_\mode, r2
msr LR_\mode, r3
msr SPSR_\mode, r4
.endm
/*
* Restore all guest registers from the vcpu struct.
*
* Assumes vcpu pointer in vcpu reg
*
* Clobbers *all* registers.
*/
.macro restore_guest_regs
restore_guest_regs_mode svc, #VCPU_SVC_REGS
restore_guest_regs_mode abt, #VCPU_ABT_REGS
restore_guest_regs_mode und, #VCPU_UND_REGS
restore_guest_regs_mode irq, #VCPU_IRQ_REGS
add r1, vcpu, #VCPU_FIQ_REGS
ldm r1, {r2-r9}
msr r8_fiq, r2
msr r9_fiq, r3
msr r10_fiq, r4
msr r11_fiq, r5
msr r12_fiq, r6
msr SP_fiq, r7
msr LR_fiq, r8
msr SPSR_fiq, r9
@ Load return state
ldr r2, [vcpu, #VCPU_PC]
ldr r3, [vcpu, #VCPU_CPSR]
msr ELR_hyp, r2
msr SPSR_cxsf, r3
@ Load user registers
ldr r2, [vcpu, #VCPU_USR_SP]
ldr r3, [vcpu, #VCPU_USR_LR]
msr SP_usr, r2
mov lr, r3
add vcpu, vcpu, #(VCPU_USR_REGS)
ldm vcpu, {r0-r12}
.endm
/*
* Save SP, LR and SPSR for a given mode. offset is the offset of
* this mode's registers from the VCPU base.
*
* Assumes vcpu pointer in vcpu reg
*
* Clobbers r2, r3, r4, r5.
*/
.macro save_guest_regs_mode mode, offset
add r2, vcpu, \offset
mrs r3, SP_\mode
mrs r4, LR_\mode
mrs r5, SPSR_\mode
stm r2, {r3, r4, r5}
.endm
/*
* Save all guest registers to the vcpu struct
* Expects guest's r0, r1, r2 on the stack.
*
* Assumes vcpu pointer in vcpu reg
*
* Clobbers r2, r3, r4, r5.
*/
.macro save_guest_regs
@ Store usr registers
add r2, vcpu, #VCPU_USR_REG(3)
stm r2, {r3-r12}
add r2, vcpu, #VCPU_USR_REG(0)
pop {r3, r4, r5} @ r0, r1, r2
stm r2, {r3, r4, r5}
mrs r2, SP_usr
mov r3, lr
str r2, [vcpu, #VCPU_USR_SP]
str r3, [vcpu, #VCPU_USR_LR]
@ Store return state
mrs r2, ELR_hyp
mrs r3, spsr
str r2, [vcpu, #VCPU_PC]
str r3, [vcpu, #VCPU_CPSR]
@ Store other guest registers
save_guest_regs_mode svc, #VCPU_SVC_REGS
save_guest_regs_mode abt, #VCPU_ABT_REGS
save_guest_regs_mode und, #VCPU_UND_REGS
save_guest_regs_mode irq, #VCPU_IRQ_REGS
.endm
/* Reads cp15 registers from hardware and stores them in memory
* @store_to_vcpu: If 0, registers are written in-order to the stack,
* otherwise to the VCPU struct pointed to by vcpup
*
* Assumes vcpu pointer in vcpu reg
*
* Clobbers r2 - r12
*/
.macro read_cp15_state store_to_vcpu
mrc p15, 0, r2, c1, c0, 0 @ SCTLR
mrc p15, 0, r3, c1, c0, 2 @ CPACR
mrc p15, 0, r4, c2, c0, 2 @ TTBCR
mrc p15, 0, r5, c3, c0, 0 @ DACR
mrrc p15, 0, r6, r7, c2 @ TTBR 0
mrrc p15, 1, r8, r9, c2 @ TTBR 1
mrc p15, 0, r10, c10, c2, 0 @ PRRR
mrc p15, 0, r11, c10, c2, 1 @ NMRR
mrc p15, 2, r12, c0, c0, 0 @ CSSELR
.if \store_to_vcpu == 0
push {r2-r12} @ Push CP15 registers
.else
str r2, [vcpu, #CP15_OFFSET(c1_SCTLR)]
str r3, [vcpu, #CP15_OFFSET(c1_CPACR)]
str r4, [vcpu, #CP15_OFFSET(c2_TTBCR)]
str r5, [vcpu, #CP15_OFFSET(c3_DACR)]
add r2, vcpu, #CP15_OFFSET(c2_TTBR0)
strd r6, r7, [r2]
add r2, vcpu, #CP15_OFFSET(c2_TTBR1)
strd r8, r9, [r2]
str r10, [vcpu, #CP15_OFFSET(c10_PRRR)]
str r11, [vcpu, #CP15_OFFSET(c10_NMRR)]
str r12, [vcpu, #CP15_OFFSET(c0_CSSELR)]
.endif
mrc p15, 0, r2, c13, c0, 1 @ CID
mrc p15, 0, r3, c13, c0, 2 @ TID_URW
mrc p15, 0, r4, c13, c0, 3 @ TID_URO
mrc p15, 0, r5, c13, c0, 4 @ TID_PRIV
mrc p15, 0, r6, c5, c0, 0 @ DFSR
mrc p15, 0, r7, c5, c0, 1 @ IFSR
mrc p15, 0, r8, c5, c1, 0 @ ADFSR
mrc p15, 0, r9, c5, c1, 1 @ AIFSR
mrc p15, 0, r10, c6, c0, 0 @ DFAR
mrc p15, 0, r11, c6, c0, 2 @ IFAR
mrc p15, 0, r12, c12, c0, 0 @ VBAR
.if \store_to_vcpu == 0
push {r2-r12} @ Push CP15 registers
.else
str r2, [vcpu, #CP15_OFFSET(c13_CID)]
str r3, [vcpu, #CP15_OFFSET(c13_TID_URW)]
str r4, [vcpu, #CP15_OFFSET(c13_TID_URO)]
str r5, [vcpu, #CP15_OFFSET(c13_TID_PRIV)]
str r6, [vcpu, #CP15_OFFSET(c5_DFSR)]
str r7, [vcpu, #CP15_OFFSET(c5_IFSR)]
str r8, [vcpu, #CP15_OFFSET(c5_ADFSR)]
str r9, [vcpu, #CP15_OFFSET(c5_AIFSR)]
str r10, [vcpu, #CP15_OFFSET(c6_DFAR)]
str r11, [vcpu, #CP15_OFFSET(c6_IFAR)]
str r12, [vcpu, #CP15_OFFSET(c12_VBAR)]
.endif
mrc p15, 0, r2, c14, c1, 0 @ CNTKCTL
.if \store_to_vcpu == 0
push {r2}
.else
str r2, [vcpu, #CP15_OFFSET(c14_CNTKCTL)]
.endif
.endm
/*
* Reads cp15 registers from memory and writes them to hardware
* @read_from_vcpu: If 0, registers are read in-order from the stack,
* otherwise from the VCPU struct pointed to by vcpup
*
* Assumes vcpu pointer in vcpu reg
*/
.macro write_cp15_state read_from_vcpu
.if \read_from_vcpu == 0
pop {r2}
.else
ldr r2, [vcpu, #CP15_OFFSET(c14_CNTKCTL)]
.endif
mcr p15, 0, r2, c14, c1, 0 @ CNTKCTL
.if \read_from_vcpu == 0
pop {r2-r12}
.else
ldr r2, [vcpu, #CP15_OFFSET(c13_CID)]
ldr r3, [vcpu, #CP15_OFFSET(c13_TID_URW)]
ldr r4, [vcpu, #CP15_OFFSET(c13_TID_URO)]
ldr r5, [vcpu, #CP15_OFFSET(c13_TID_PRIV)]
ldr r6, [vcpu, #CP15_OFFSET(c5_DFSR)]
ldr r7, [vcpu, #CP15_OFFSET(c5_IFSR)]
ldr r8, [vcpu, #CP15_OFFSET(c5_ADFSR)]
ldr r9, [vcpu, #CP15_OFFSET(c5_AIFSR)]
ldr r10, [vcpu, #CP15_OFFSET(c6_DFAR)]
ldr r11, [vcpu, #CP15_OFFSET(c6_IFAR)]
ldr r12, [vcpu, #CP15_OFFSET(c12_VBAR)]
.endif
mcr p15, 0, r2, c13, c0, 1 @ CID
mcr p15, 0, r3, c13, c0, 2 @ TID_URW
mcr p15, 0, r4, c13, c0, 3 @ TID_URO
mcr p15, 0, r5, c13, c0, 4 @ TID_PRIV
mcr p15, 0, r6, c5, c0, 0 @ DFSR
mcr p15, 0, r7, c5, c0, 1 @ IFSR
mcr p15, 0, r8, c5, c1, 0 @ ADFSR
mcr p15, 0, r9, c5, c1, 1 @ AIFSR
mcr p15, 0, r10, c6, c0, 0 @ DFAR
mcr p15, 0, r11, c6, c0, 2 @ IFAR
mcr p15, 0, r12, c12, c0, 0 @ VBAR
.if \read_from_vcpu == 0
pop {r2-r12}
.else
ldr r2, [vcpu, #CP15_OFFSET(c1_SCTLR)]
ldr r3, [vcpu, #CP15_OFFSET(c1_CPACR)]
ldr r4, [vcpu, #CP15_OFFSET(c2_TTBCR)]
ldr r5, [vcpu, #CP15_OFFSET(c3_DACR)]
add r12, vcpu, #CP15_OFFSET(c2_TTBR0)
ldrd r6, r7, [r12]
add r12, vcpu, #CP15_OFFSET(c2_TTBR1)
ldrd r8, r9, [r12]
ldr r10, [vcpu, #CP15_OFFSET(c10_PRRR)]
ldr r11, [vcpu, #CP15_OFFSET(c10_NMRR)]
ldr r12, [vcpu, #CP15_OFFSET(c0_CSSELR)]
.endif
mcr p15, 0, r2, c1, c0, 0 @ SCTLR
mcr p15, 0, r3, c1, c0, 2 @ CPACR
mcr p15, 0, r4, c2, c0, 2 @ TTBCR
mcr p15, 0, r5, c3, c0, 0 @ DACR
mcrr p15, 0, r6, r7, c2 @ TTBR 0
mcrr p15, 1, r8, r9, c2 @ TTBR 1
mcr p15, 0, r10, c10, c2, 0 @ PRRR
mcr p15, 0, r11, c10, c2, 1 @ NMRR
mcr p15, 2, r12, c0, c0, 0 @ CSSELR
.endm
/*
* Save the VGIC CPU state into memory
*
* Assumes vcpu pointer in vcpu reg
*/
.macro save_vgic_state
#ifdef CONFIG_KVM_ARM_VGIC
/* Get VGIC VCTRL base into r2 */
ldr r2, [vcpu, #VCPU_KVM]
ldr r2, [r2, #KVM_VGIC_VCTRL]
cmp r2, #0
beq 2f
/* Compute the address of struct vgic_cpu */
add r11, vcpu, #VCPU_VGIC_CPU
/* Save all interesting registers */
ldr r3, [r2, #GICH_HCR]
ldr r4, [r2, #GICH_VMCR]
ldr r5, [r2, #GICH_MISR]
ldr r6, [r2, #GICH_EISR0]
ldr r7, [r2, #GICH_EISR1]
ldr r8, [r2, #GICH_ELRSR0]
ldr r9, [r2, #GICH_ELRSR1]
ldr r10, [r2, #GICH_APR]
str r3, [r11, #VGIC_CPU_HCR]
str r4, [r11, #VGIC_CPU_VMCR]
str r5, [r11, #VGIC_CPU_MISR]
str r6, [r11, #VGIC_CPU_EISR]
str r7, [r11, #(VGIC_CPU_EISR + 4)]
str r8, [r11, #VGIC_CPU_ELRSR]
str r9, [r11, #(VGIC_CPU_ELRSR + 4)]
str r10, [r11, #VGIC_CPU_APR]
/* Clear GICH_HCR */
mov r5, #0
str r5, [r2, #GICH_HCR]
/* Save list registers */
add r2, r2, #GICH_LR0
add r3, r11, #VGIC_CPU_LR
ldr r4, [r11, #VGIC_CPU_NR_LR]
1: ldr r6, [r2], #4
str r6, [r3], #4
subs r4, r4, #1
bne 1b
2:
#endif
.endm
/*
* Restore the VGIC CPU state from memory
*
* Assumes vcpu pointer in vcpu reg
*/
.macro restore_vgic_state
#ifdef CONFIG_KVM_ARM_VGIC
/* Get VGIC VCTRL base into r2 */
ldr r2, [vcpu, #VCPU_KVM]
ldr r2, [r2, #KVM_VGIC_VCTRL]
cmp r2, #0
beq 2f
/* Compute the address of struct vgic_cpu */
add r11, vcpu, #VCPU_VGIC_CPU
/* We only restore a minimal set of registers */
ldr r3, [r11, #VGIC_CPU_HCR]
ldr r4, [r11, #VGIC_CPU_VMCR]
ldr r8, [r11, #VGIC_CPU_APR]
str r3, [r2, #GICH_HCR]
str r4, [r2, #GICH_VMCR]
str r8, [r2, #GICH_APR]
/* Restore list registers */
add r2, r2, #GICH_LR0
add r3, r11, #VGIC_CPU_LR
ldr r4, [r11, #VGIC_CPU_NR_LR]
1: ldr r6, [r3], #4
str r6, [r2], #4
subs r4, r4, #1
bne 1b
2:
#endif
.endm
#define CNTHCTL_PL1PCTEN (1 << 0)
#define CNTHCTL_PL1PCEN (1 << 1)
/*
* Save the timer state onto the VCPU and allow physical timer/counter access
* for the host.
*
* Assumes vcpu pointer in vcpu reg
* Clobbers r2-r5
*/
.macro save_timer_state
#ifdef CONFIG_KVM_ARM_TIMER
ldr r4, [vcpu, #VCPU_KVM]
ldr r2, [r4, #KVM_TIMER_ENABLED]
cmp r2, #0
beq 1f
mrc p15, 0, r2, c14, c3, 1 @ CNTV_CTL
str r2, [vcpu, #VCPU_TIMER_CNTV_CTL]
bic r2, #1 @ Clear ENABLE
mcr p15, 0, r2, c14, c3, 1 @ CNTV_CTL
isb
mrrc p15, 3, r2, r3, c14 @ CNTV_CVAL
ldr r4, =VCPU_TIMER_CNTV_CVAL
add r5, vcpu, r4
strd r2, r3, [r5]
1:
#endif
@ Allow physical timer/counter access for the host
mrc p15, 4, r2, c14, c1, 0 @ CNTHCTL
orr r2, r2, #(CNTHCTL_PL1PCEN | CNTHCTL_PL1PCTEN)
mcr p15, 4, r2, c14, c1, 0 @ CNTHCTL
.endm
/*
* Load the timer state from the VCPU and deny physical timer/counter access
* for the host.
*
* Assumes vcpu pointer in vcpu reg
* Clobbers r2-r5
*/
.macro restore_timer_state
@ Disallow physical timer access for the guest
@ Physical counter access is allowed
mrc p15, 4, r2, c14, c1, 0 @ CNTHCTL
orr r2, r2, #CNTHCTL_PL1PCTEN
bic r2, r2, #CNTHCTL_PL1PCEN
mcr p15, 4, r2, c14, c1, 0 @ CNTHCTL
#ifdef CONFIG_KVM_ARM_TIMER
ldr r4, [vcpu, #VCPU_KVM]
ldr r2, [r4, #KVM_TIMER_ENABLED]
cmp r2, #0
beq 1f
ldr r2, [r4, #KVM_TIMER_CNTVOFF]
ldr r3, [r4, #(KVM_TIMER_CNTVOFF + 4)]
mcrr p15, 4, r2, r3, c14 @ CNTVOFF
ldr r4, =VCPU_TIMER_CNTV_CVAL
add r5, vcpu, r4
ldrd r2, r3, [r5]
mcrr p15, 3, r2, r3, c14 @ CNTV_CVAL
isb
ldr r2, [vcpu, #VCPU_TIMER_CNTV_CTL]
and r2, r2, #3
mcr p15, 0, r2, c14, c3, 1 @ CNTV_CTL
1:
#endif
.endm
.equ vmentry, 0
.equ vmexit, 1
/* Configures the HSTR (Hyp System Trap Register) on entry/return
* (hardware reset value is 0) */
.macro set_hstr operation
mrc p15, 4, r2, c1, c1, 3
ldr r3, =HSTR_T(15)
.if \operation == vmentry
orr r2, r2, r3 @ Trap CR{15}
.else
bic r2, r2, r3 @ Don't trap any CRx accesses
.endif
mcr p15, 4, r2, c1, c1, 3
.endm
/* Configures the HCPTR (Hyp Coprocessor Trap Register) on entry/return
* (hardware reset value is 0). Keep previous value in r2. */
.macro set_hcptr operation, mask
mrc p15, 4, r2, c1, c1, 2
ldr r3, =\mask
.if \operation == vmentry
orr r3, r2, r3 @ Trap coproc-accesses defined in mask
.else
bic r3, r2, r3 @ Don't trap defined coproc-accesses
.endif
mcr p15, 4, r3, c1, c1, 2
.endm
/* Configures the HDCR (Hyp Debug Configuration Register) on entry/return
* (hardware reset value is 0) */
.macro set_hdcr operation
mrc p15, 4, r2, c1, c1, 1
ldr r3, =(HDCR_TPM|HDCR_TPMCR)
.if \operation == vmentry
orr r2, r2, r3 @ Trap some perfmon accesses
.else
bic r2, r2, r3 @ Don't trap any perfmon accesses
.endif
mcr p15, 4, r2, c1, c1, 1
.endm
/* Enable/Disable: stage-2 trans., trap interrupts, trap wfi, trap smc */
.macro configure_hyp_role operation
mrc p15, 4, r2, c1, c1, 0 @ HCR
bic r2, r2, #HCR_VIRT_EXCP_MASK
ldr r3, =HCR_GUEST_MASK
.if \operation == vmentry
orr r2, r2, r3
ldr r3, [vcpu, #VCPU_IRQ_LINES]
orr r2, r2, r3
.else
bic r2, r2, r3
.endif
mcr p15, 4, r2, c1, c1, 0
.endm
.macro load_vcpu
mrc p15, 4, vcpu, c13, c0, 2 @ HTPIDR
.endm
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