--- /dev/null
+/*
+* This file is subject to the terms and conditions of the GNU General Public
+* License. See the file "COPYING" in the main directory of this archive
+* for more details.
+*
+* Main entry point for the guest, exception handling.
+*
+* Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved.
+* Authors: Sanjay Lal <sanjayl@kymasys.com>
+*/
+
+#include <asm/asm.h>
+#include <asm/asmmacro.h>
+#include <asm/regdef.h>
+#include <asm/mipsregs.h>
+#include <asm/stackframe.h>
+#include <asm/asm-offsets.h>
+
+
+#define _C_LABEL(x) x
+#define MIPSX(name) mips32_ ## name
+#define CALLFRAME_SIZ 32
+
+/*
+ * VECTOR
+ * exception vector entrypoint
+ */
+#define VECTOR(x, regmask) \
+ .ent _C_LABEL(x),0; \
+ EXPORT(x);
+
+#define VECTOR_END(x) \
+ EXPORT(x);
+
+/* Overload, Danger Will Robinson!! */
+#define PT_HOST_ASID PT_BVADDR
+#define PT_HOST_USERLOCAL PT_EPC
+
+#define CP0_DDATA_LO $28,3
+#define CP0_EBASE $15,1
+
+#define CP0_INTCTL $12,1
+#define CP0_SRSCTL $12,2
+#define CP0_SRSMAP $12,3
+#define CP0_HWRENA $7,0
+
+/* Resume Flags */
+#define RESUME_FLAG_HOST (1<<1) /* Resume host? */
+
+#define RESUME_GUEST 0
+#define RESUME_HOST RESUME_FLAG_HOST
+
+/*
+ * __kvm_mips_vcpu_run: entry point to the guest
+ * a0: run
+ * a1: vcpu
+ */
+
+FEXPORT(__kvm_mips_vcpu_run)
+ .set push
+ .set noreorder
+ .set noat
+
+ /* k0/k1 not being used in host kernel context */
+ addiu k1,sp, -PT_SIZE
+ LONG_S $0, PT_R0(k1)
+ LONG_S $1, PT_R1(k1)
+ LONG_S $2, PT_R2(k1)
+ LONG_S $3, PT_R3(k1)
+
+ LONG_S $4, PT_R4(k1)
+ LONG_S $5, PT_R5(k1)
+ LONG_S $6, PT_R6(k1)
+ LONG_S $7, PT_R7(k1)
+
+ LONG_S $8, PT_R8(k1)
+ LONG_S $9, PT_R9(k1)
+ LONG_S $10, PT_R10(k1)
+ LONG_S $11, PT_R11(k1)
+ LONG_S $12, PT_R12(k1)
+ LONG_S $13, PT_R13(k1)
+ LONG_S $14, PT_R14(k1)
+ LONG_S $15, PT_R15(k1)
+ LONG_S $16, PT_R16(k1)
+ LONG_S $17, PT_R17(k1)
+
+ LONG_S $18, PT_R18(k1)
+ LONG_S $19, PT_R19(k1)
+ LONG_S $20, PT_R20(k1)
+ LONG_S $21, PT_R21(k1)
+ LONG_S $22, PT_R22(k1)
+ LONG_S $23, PT_R23(k1)
+ LONG_S $24, PT_R24(k1)
+ LONG_S $25, PT_R25(k1)
+
+ /* XXXKYMA k0/k1 not saved, not being used if we got here through an ioctl() */
+
+ LONG_S $28, PT_R28(k1)
+ LONG_S $29, PT_R29(k1)
+ LONG_S $30, PT_R30(k1)
+ LONG_S $31, PT_R31(k1)
+
+ /* Save hi/lo */
+ mflo v0
+ LONG_S v0, PT_LO(k1)
+ mfhi v1
+ LONG_S v1, PT_HI(k1)
+
+ /* Save host status */
+ mfc0 v0, CP0_STATUS
+ LONG_S v0, PT_STATUS(k1)
+
+ /* Save host ASID, shove it into the BVADDR location */
+ mfc0 v1,CP0_ENTRYHI
+ andi v1, 0xff
+ LONG_S v1, PT_HOST_ASID(k1)
+
+ /* Save DDATA_LO, will be used to store pointer to vcpu */
+ mfc0 v1, CP0_DDATA_LO
+ LONG_S v1, PT_HOST_USERLOCAL(k1)
+
+ /* DDATA_LO has pointer to vcpu */
+ mtc0 a1,CP0_DDATA_LO
+
+ /* Offset into vcpu->arch */
+ addiu k1, a1, VCPU_HOST_ARCH
+
+ /* Save the host stack to VCPU, used for exception processing when we exit from the Guest */
+ LONG_S sp, VCPU_HOST_STACK(k1)
+
+ /* Save the kernel gp as well */
+ LONG_S gp, VCPU_HOST_GP(k1)
+
+ /* Setup status register for running the guest in UM, interrupts are disabled */
+ li k0,(ST0_EXL | KSU_USER| ST0_BEV)
+ mtc0 k0,CP0_STATUS
+ ehb
+
+ /* load up the new EBASE */
+ LONG_L k0, VCPU_GUEST_EBASE(k1)
+ mtc0 k0,CP0_EBASE
+
+ /* Now that the new EBASE has been loaded, unset BEV, set interrupt mask as it was
+ * but make sure that timer interrupts are enabled
+ */
+ li k0,(ST0_EXL | KSU_USER | ST0_IE)
+ andi v0, v0, ST0_IM
+ or k0, k0, v0
+ mtc0 k0,CP0_STATUS
+ ehb
+
+
+ /* Set Guest EPC */
+ LONG_L t0, VCPU_PC(k1)
+ mtc0 t0, CP0_EPC
+
+FEXPORT(__kvm_mips_load_asid)
+ /* Set the ASID for the Guest Kernel */
+ sll t0, t0, 1 /* with kseg0 @ 0x40000000, kernel */
+ /* addresses shift to 0x80000000 */
+ bltz t0, 1f /* If kernel */
+ addiu t1, k1, VCPU_GUEST_KERNEL_ASID /* (BD) */
+ addiu t1, k1, VCPU_GUEST_USER_ASID /* else user */
+1:
+ /* t1: contains the base of the ASID array, need to get the cpu id */
+ LONG_L t2, TI_CPU($28) /* smp_processor_id */
+ sll t2, t2, 2 /* x4 */
+ addu t3, t1, t2
+ LONG_L k0, (t3)
+ andi k0, k0, 0xff
+ mtc0 k0,CP0_ENTRYHI
+ ehb
+
+ /* Disable RDHWR access */
+ mtc0 zero, CP0_HWRENA
+
+ /* Now load up the Guest Context from VCPU */
+ LONG_L $1, VCPU_R1(k1)
+ LONG_L $2, VCPU_R2(k1)
+ LONG_L $3, VCPU_R3(k1)
+
+ LONG_L $4, VCPU_R4(k1)
+ LONG_L $5, VCPU_R5(k1)
+ LONG_L $6, VCPU_R6(k1)
+ LONG_L $7, VCPU_R7(k1)
+
+ LONG_L $8, VCPU_R8(k1)
+ LONG_L $9, VCPU_R9(k1)
+ LONG_L $10, VCPU_R10(k1)
+ LONG_L $11, VCPU_R11(k1)
+ LONG_L $12, VCPU_R12(k1)
+ LONG_L $13, VCPU_R13(k1)
+ LONG_L $14, VCPU_R14(k1)
+ LONG_L $15, VCPU_R15(k1)
+ LONG_L $16, VCPU_R16(k1)
+ LONG_L $17, VCPU_R17(k1)
+ LONG_L $18, VCPU_R18(k1)
+ LONG_L $19, VCPU_R19(k1)
+ LONG_L $20, VCPU_R20(k1)
+ LONG_L $21, VCPU_R21(k1)
+ LONG_L $22, VCPU_R22(k1)
+ LONG_L $23, VCPU_R23(k1)
+ LONG_L $24, VCPU_R24(k1)
+ LONG_L $25, VCPU_R25(k1)
+
+ /* k0/k1 loaded up later */
+
+ LONG_L $28, VCPU_R28(k1)
+ LONG_L $29, VCPU_R29(k1)
+ LONG_L $30, VCPU_R30(k1)
+ LONG_L $31, VCPU_R31(k1)
+
+ /* Restore hi/lo */
+ LONG_L k0, VCPU_LO(k1)
+ mtlo k0
+
+ LONG_L k0, VCPU_HI(k1)
+ mthi k0
+
+FEXPORT(__kvm_mips_load_k0k1)
+ /* Restore the guest's k0/k1 registers */
+ LONG_L k0, VCPU_R26(k1)
+ LONG_L k1, VCPU_R27(k1)
+
+ /* Jump to guest */
+ eret
+ .set pop
+
+VECTOR(MIPSX(exception), unknown)
+/*
+ * Find out what mode we came from and jump to the proper handler.
+ */
+ .set push
+ .set noat
+ .set noreorder
+ mtc0 k0, CP0_ERROREPC #01: Save guest k0
+ ehb #02:
+
+ mfc0 k0, CP0_EBASE #02: Get EBASE
+ srl k0, k0, 10 #03: Get rid of CPUNum
+ sll k0, k0, 10 #04
+ LONG_S k1, 0x3000(k0) #05: Save k1 @ offset 0x3000
+ addiu k0, k0, 0x2000 #06: Exception handler is installed @ offset 0x2000
+ j k0 #07: jump to the function
+ nop #08: branch delay slot
+ .set push
+VECTOR_END(MIPSX(exceptionEnd))
+.end MIPSX(exception)
+
+/*
+ * Generic Guest exception handler. We end up here when the guest
+ * does something that causes a trap to kernel mode.
+ *
+ */
+NESTED (MIPSX(GuestException), CALLFRAME_SIZ, ra)
+ .set push
+ .set noat
+ .set noreorder
+
+ /* Get the VCPU pointer from DDTATA_LO */
+ mfc0 k1, CP0_DDATA_LO
+ addiu k1, k1, VCPU_HOST_ARCH
+
+ /* Start saving Guest context to VCPU */
+ LONG_S $0, VCPU_R0(k1)
+ LONG_S $1, VCPU_R1(k1)
+ LONG_S $2, VCPU_R2(k1)
+ LONG_S $3, VCPU_R3(k1)
+ LONG_S $4, VCPU_R4(k1)
+ LONG_S $5, VCPU_R5(k1)
+ LONG_S $6, VCPU_R6(k1)
+ LONG_S $7, VCPU_R7(k1)
+ LONG_S $8, VCPU_R8(k1)
+ LONG_S $9, VCPU_R9(k1)
+ LONG_S $10, VCPU_R10(k1)
+ LONG_S $11, VCPU_R11(k1)
+ LONG_S $12, VCPU_R12(k1)
+ LONG_S $13, VCPU_R13(k1)
+ LONG_S $14, VCPU_R14(k1)
+ LONG_S $15, VCPU_R15(k1)
+ LONG_S $16, VCPU_R16(k1)
+ LONG_S $17,VCPU_R17(k1)
+ LONG_S $18, VCPU_R18(k1)
+ LONG_S $19, VCPU_R19(k1)
+ LONG_S $20, VCPU_R20(k1)
+ LONG_S $21, VCPU_R21(k1)
+ LONG_S $22, VCPU_R22(k1)
+ LONG_S $23, VCPU_R23(k1)
+ LONG_S $24, VCPU_R24(k1)
+ LONG_S $25, VCPU_R25(k1)
+
+ /* Guest k0/k1 saved later */
+
+ LONG_S $28, VCPU_R28(k1)
+ LONG_S $29, VCPU_R29(k1)
+ LONG_S $30, VCPU_R30(k1)
+ LONG_S $31, VCPU_R31(k1)
+
+ /* We need to save hi/lo and restore them on
+ * the way out
+ */
+ mfhi t0
+ LONG_S t0, VCPU_HI(k1)
+
+ mflo t0
+ LONG_S t0, VCPU_LO(k1)
+
+ /* Finally save guest k0/k1 to VCPU */
+ mfc0 t0, CP0_ERROREPC
+ LONG_S t0, VCPU_R26(k1)
+
+ /* Get GUEST k1 and save it in VCPU */
+ la t1, ~0x2ff
+ mfc0 t0, CP0_EBASE
+ and t0, t0, t1
+ LONG_L t0, 0x3000(t0)
+ LONG_S t0, VCPU_R27(k1)
+
+ /* Now that context has been saved, we can use other registers */
+
+ /* Restore vcpu */
+ mfc0 a1, CP0_DDATA_LO
+ move s1, a1
+
+ /* Restore run (vcpu->run) */
+ LONG_L a0, VCPU_RUN(a1)
+ /* Save pointer to run in s0, will be saved by the compiler */
+ move s0, a0
+
+
+ /* Save Host level EPC, BadVaddr and Cause to VCPU, useful to process the exception */
+ mfc0 k0,CP0_EPC
+ LONG_S k0, VCPU_PC(k1)
+
+ mfc0 k0, CP0_BADVADDR
+ LONG_S k0, VCPU_HOST_CP0_BADVADDR(k1)
+
+ mfc0 k0, CP0_CAUSE
+ LONG_S k0, VCPU_HOST_CP0_CAUSE(k1)
+
+ mfc0 k0, CP0_ENTRYHI
+ LONG_S k0, VCPU_HOST_ENTRYHI(k1)
+
+ /* Now restore the host state just enough to run the handlers */
+
+ /* Swtich EBASE to the one used by Linux */
+ /* load up the host EBASE */
+ mfc0 v0, CP0_STATUS
+
+ .set at
+ or k0, v0, ST0_BEV
+ .set noat
+
+ mtc0 k0, CP0_STATUS
+ ehb
+
+ LONG_L k0, VCPU_HOST_EBASE(k1)
+ mtc0 k0,CP0_EBASE
+
+
+ /* Now that the new EBASE has been loaded, unset BEV and KSU_USER */
+ .set at
+ and v0, v0, ~(ST0_EXL | KSU_USER | ST0_IE)
+ or v0, v0, ST0_CU0
+ .set noat
+ mtc0 v0, CP0_STATUS
+ ehb
+
+ /* Load up host GP */
+ LONG_L gp, VCPU_HOST_GP(k1)
+
+ /* Need a stack before we can jump to "C" */
+ LONG_L sp, VCPU_HOST_STACK(k1)
+
+ /* Saved host state */
+ addiu sp,sp, -PT_SIZE
+
+ /* XXXKYMA do we need to load the host ASID, maybe not because the
+ * kernel entries are marked GLOBAL, need to verify
+ */
+
+ /* Restore host DDATA_LO */
+ LONG_L k0, PT_HOST_USERLOCAL(sp)
+ mtc0 k0, CP0_DDATA_LO
+
+ /* Restore RDHWR access */
+ la k0, 0x2000000F
+ mtc0 k0, CP0_HWRENA
+
+ /* Jump to handler */
+FEXPORT(__kvm_mips_jump_to_handler)
+ /* XXXKYMA: not sure if this is safe, how large is the stack?? */
+ /* Now jump to the kvm_mips_handle_exit() to see if we can deal with this in the kernel */
+ la t9,kvm_mips_handle_exit
+ jalr.hb t9
+ addiu sp,sp, -CALLFRAME_SIZ /* BD Slot */
+
+ /* Return from handler Make sure interrupts are disabled */
+ di
+ ehb
+
+ /* XXXKYMA: k0/k1 could have been blown away if we processed an exception
+ * while we were handling the exception from the guest, reload k1
+ */
+ move k1, s1
+ addiu k1, k1, VCPU_HOST_ARCH
+
+ /* Check return value, should tell us if we are returning to the host (handle I/O etc)
+ * or resuming the guest
+ */
+ andi t0, v0, RESUME_HOST
+ bnez t0, __kvm_mips_return_to_host
+ nop
+
+__kvm_mips_return_to_guest:
+ /* Put the saved pointer to vcpu (s1) back into the DDATA_LO Register */
+ mtc0 s1, CP0_DDATA_LO
+
+ /* Load up the Guest EBASE to minimize the window where BEV is set */
+ LONG_L t0, VCPU_GUEST_EBASE(k1)
+
+ /* Switch EBASE back to the one used by KVM */
+ mfc0 v1, CP0_STATUS
+ .set at
+ or k0, v1, ST0_BEV
+ .set noat
+ mtc0 k0, CP0_STATUS
+ ehb
+ mtc0 t0,CP0_EBASE
+
+ /* Setup status register for running guest in UM */
+ .set at
+ or v1, v1, (ST0_EXL | KSU_USER | ST0_IE)
+ and v1, v1, ~ST0_CU0
+ .set noat
+ mtc0 v1, CP0_STATUS
+ ehb
+
+
+ /* Set Guest EPC */
+ LONG_L t0, VCPU_PC(k1)
+ mtc0 t0, CP0_EPC
+
+ /* Set the ASID for the Guest Kernel */
+ sll t0, t0, 1 /* with kseg0 @ 0x40000000, kernel */
+ /* addresses shift to 0x80000000 */
+ bltz t0, 1f /* If kernel */
+ addiu t1, k1, VCPU_GUEST_KERNEL_ASID /* (BD) */
+ addiu t1, k1, VCPU_GUEST_USER_ASID /* else user */
+1:
+ /* t1: contains the base of the ASID array, need to get the cpu id */
+ LONG_L t2, TI_CPU($28) /* smp_processor_id */
+ sll t2, t2, 2 /* x4 */
+ addu t3, t1, t2
+ LONG_L k0, (t3)
+ andi k0, k0, 0xff
+ mtc0 k0,CP0_ENTRYHI
+ ehb
+
+ /* Disable RDHWR access */
+ mtc0 zero, CP0_HWRENA
+
+ /* load the guest context from VCPU and return */
+ LONG_L $0, VCPU_R0(k1)
+ LONG_L $1, VCPU_R1(k1)
+ LONG_L $2, VCPU_R2(k1)
+ LONG_L $3, VCPU_R3(k1)
+ LONG_L $4, VCPU_R4(k1)
+ LONG_L $5, VCPU_R5(k1)
+ LONG_L $6, VCPU_R6(k1)
+ LONG_L $7, VCPU_R7(k1)
+ LONG_L $8, VCPU_R8(k1)
+ LONG_L $9, VCPU_R9(k1)
+ LONG_L $10, VCPU_R10(k1)
+ LONG_L $11, VCPU_R11(k1)
+ LONG_L $12, VCPU_R12(k1)
+ LONG_L $13, VCPU_R13(k1)
+ LONG_L $14, VCPU_R14(k1)
+ LONG_L $15, VCPU_R15(k1)
+ LONG_L $16, VCPU_R16(k1)
+ LONG_L $17, VCPU_R17(k1)
+ LONG_L $18, VCPU_R18(k1)
+ LONG_L $19, VCPU_R19(k1)
+ LONG_L $20, VCPU_R20(k1)
+ LONG_L $21, VCPU_R21(k1)
+ LONG_L $22, VCPU_R22(k1)
+ LONG_L $23, VCPU_R23(k1)
+ LONG_L $24, VCPU_R24(k1)
+ LONG_L $25, VCPU_R25(k1)
+
+ /* $/k1 loaded later */
+ LONG_L $28, VCPU_R28(k1)
+ LONG_L $29, VCPU_R29(k1)
+ LONG_L $30, VCPU_R30(k1)
+ LONG_L $31, VCPU_R31(k1)
+
+FEXPORT(__kvm_mips_skip_guest_restore)
+ LONG_L k0, VCPU_HI(k1)
+ mthi k0
+
+ LONG_L k0, VCPU_LO(k1)
+ mtlo k0
+
+ LONG_L k0, VCPU_R26(k1)
+ LONG_L k1, VCPU_R27(k1)
+
+ eret
+
+__kvm_mips_return_to_host:
+ /* EBASE is already pointing to Linux */
+ LONG_L k1, VCPU_HOST_STACK(k1)
+ addiu k1,k1, -PT_SIZE
+
+ /* Restore host DDATA_LO */
+ LONG_L k0, PT_HOST_USERLOCAL(k1)
+ mtc0 k0, CP0_DDATA_LO
+
+ /* Restore host ASID */
+ LONG_L k0, PT_HOST_ASID(sp)
+ andi k0, 0xff
+ mtc0 k0,CP0_ENTRYHI
+ ehb
+
+ /* Load context saved on the host stack */
+ LONG_L $0, PT_R0(k1)
+ LONG_L $1, PT_R1(k1)
+
+ /* r2/v0 is the return code, shift it down by 2 (arithmetic) to recover the err code */
+ sra k0, v0, 2
+ move $2, k0
+
+ LONG_L $3, PT_R3(k1)
+ LONG_L $4, PT_R4(k1)
+ LONG_L $5, PT_R5(k1)
+ LONG_L $6, PT_R6(k1)
+ LONG_L $7, PT_R7(k1)
+ LONG_L $8, PT_R8(k1)
+ LONG_L $9, PT_R9(k1)
+ LONG_L $10, PT_R10(k1)
+ LONG_L $11, PT_R11(k1)
+ LONG_L $12, PT_R12(k1)
+ LONG_L $13, PT_R13(k1)
+ LONG_L $14, PT_R14(k1)
+ LONG_L $15, PT_R15(k1)
+ LONG_L $16, PT_R16(k1)
+ LONG_L $17, PT_R17(k1)
+ LONG_L $18, PT_R18(k1)
+ LONG_L $19, PT_R19(k1)
+ LONG_L $20, PT_R20(k1)
+ LONG_L $21, PT_R21(k1)
+ LONG_L $22, PT_R22(k1)
+ LONG_L $23, PT_R23(k1)
+ LONG_L $24, PT_R24(k1)
+ LONG_L $25, PT_R25(k1)
+
+ /* Host k0/k1 were not saved */
+
+ LONG_L $28, PT_R28(k1)
+ LONG_L $29, PT_R29(k1)
+ LONG_L $30, PT_R30(k1)
+
+ LONG_L k0, PT_HI(k1)
+ mthi k0
+
+ LONG_L k0, PT_LO(k1)
+ mtlo k0
+
+ /* Restore RDHWR access */
+ la k0, 0x2000000F
+ mtc0 k0, CP0_HWRENA
+
+
+ /* Restore RA, which is the address we will return to */
+ LONG_L ra, PT_R31(k1)
+ j ra
+ nop
+
+ .set pop
+VECTOR_END(MIPSX(GuestExceptionEnd))
+.end MIPSX(GuestException)
+
+MIPSX(exceptions):
+ ####
+ ##### The exception handlers.
+ #####
+ .word _C_LABEL(MIPSX(GuestException)) # 0
+ .word _C_LABEL(MIPSX(GuestException)) # 1
+ .word _C_LABEL(MIPSX(GuestException)) # 2
+ .word _C_LABEL(MIPSX(GuestException)) # 3
+ .word _C_LABEL(MIPSX(GuestException)) # 4
+ .word _C_LABEL(MIPSX(GuestException)) # 5
+ .word _C_LABEL(MIPSX(GuestException)) # 6
+ .word _C_LABEL(MIPSX(GuestException)) # 7
+ .word _C_LABEL(MIPSX(GuestException)) # 8
+ .word _C_LABEL(MIPSX(GuestException)) # 9
+ .word _C_LABEL(MIPSX(GuestException)) # 10
+ .word _C_LABEL(MIPSX(GuestException)) # 11
+ .word _C_LABEL(MIPSX(GuestException)) # 12
+ .word _C_LABEL(MIPSX(GuestException)) # 13
+ .word _C_LABEL(MIPSX(GuestException)) # 14
+ .word _C_LABEL(MIPSX(GuestException)) # 15
+ .word _C_LABEL(MIPSX(GuestException)) # 16
+ .word _C_LABEL(MIPSX(GuestException)) # 17
+ .word _C_LABEL(MIPSX(GuestException)) # 18
+ .word _C_LABEL(MIPSX(GuestException)) # 19
+ .word _C_LABEL(MIPSX(GuestException)) # 20
+ .word _C_LABEL(MIPSX(GuestException)) # 21
+ .word _C_LABEL(MIPSX(GuestException)) # 22
+ .word _C_LABEL(MIPSX(GuestException)) # 23
+ .word _C_LABEL(MIPSX(GuestException)) # 24
+ .word _C_LABEL(MIPSX(GuestException)) # 25
+ .word _C_LABEL(MIPSX(GuestException)) # 26
+ .word _C_LABEL(MIPSX(GuestException)) # 27
+ .word _C_LABEL(MIPSX(GuestException)) # 28
+ .word _C_LABEL(MIPSX(GuestException)) # 29
+ .word _C_LABEL(MIPSX(GuestException)) # 30
+ .word _C_LABEL(MIPSX(GuestException)) # 31
+
+
+/* This routine makes changes to the instruction stream effective to the hardware.
+ * It should be called after the instruction stream is written.
+ * On return, the new instructions are effective.
+ * Inputs:
+ * a0 = Start address of new instruction stream
+ * a1 = Size, in bytes, of new instruction stream
+ */
+
+#define HW_SYNCI_Step $1
+LEAF(MIPSX(SyncICache))
+ .set push
+ .set mips32r2
+ beq a1, zero, 20f
+ nop
+ addu a1, a0, a1
+ rdhwr v0, HW_SYNCI_Step
+ beq v0, zero, 20f
+ nop
+
+10:
+ synci 0(a0)
+ addu a0, a0, v0
+ sltu v1, a0, a1
+ bne v1, zero, 10b
+ nop
+ sync
+20:
+ jr.hb ra
+ nop
+ .set pop
+END(MIPSX(SyncICache))