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linux-zen-server/arch/mips/kernel/genex.S

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2023-08-30 17:53:23 +02:00
/*
* 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.
*
* Copyright (C) 1994 - 2000, 2001, 2003 Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
* Copyright (C) 2002, 2007 Maciej W. Rozycki
* Copyright (C) 2001, 2012 MIPS Technologies, Inc. All rights reserved.
*/
#include <linux/init.h>
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/cacheops.h>
#include <asm/irqflags.h>
#include <asm/regdef.h>
#include <asm/fpregdef.h>
#include <asm/mipsregs.h>
#include <asm/stackframe.h>
#include <asm/sync.h>
#include <asm/thread_info.h>
__INIT
/*
* General exception vector for all other CPUs.
*
* Be careful when changing this, it has to be at most 128 bytes
* to fit into space reserved for the exception handler.
*/
NESTED(except_vec3_generic, 0, sp)
.set push
.set noat
mfc0 k1, CP0_CAUSE
andi k1, k1, 0x7c
#ifdef CONFIG_64BIT
dsll k1, k1, 1
#endif
PTR_L k0, exception_handlers(k1)
jr k0
.set pop
END(except_vec3_generic)
/*
* General exception handler for CPUs with virtual coherency exception.
*
* Be careful when changing this, it has to be at most 256 (as a special
* exception) bytes to fit into space reserved for the exception handler.
*/
NESTED(except_vec3_r4000, 0, sp)
.set push
.set arch=r4000
.set noat
mfc0 k1, CP0_CAUSE
li k0, 31<<2
andi k1, k1, 0x7c
.set push
.set noreorder
.set nomacro
beq k1, k0, handle_vced
li k0, 14<<2
beq k1, k0, handle_vcei
#ifdef CONFIG_64BIT
dsll k1, k1, 1
#endif
.set pop
PTR_L k0, exception_handlers(k1)
jr k0
/*
* Big shit, we now may have two dirty primary cache lines for the same
* physical address. We can safely invalidate the line pointed to by
* c0_badvaddr because after return from this exception handler the
* load / store will be re-executed.
*/
handle_vced:
MFC0 k0, CP0_BADVADDR
li k1, -4 # Is this ...
and k0, k1 # ... really needed?
mtc0 zero, CP0_TAGLO
cache Index_Store_Tag_D, (k0)
cache Hit_Writeback_Inv_SD, (k0)
#ifdef CONFIG_PROC_FS
PTR_LA k0, vced_count
lw k1, (k0)
addiu k1, 1
sw k1, (k0)
#endif
eret
handle_vcei:
MFC0 k0, CP0_BADVADDR
cache Hit_Writeback_Inv_SD, (k0) # also cleans pi
#ifdef CONFIG_PROC_FS
PTR_LA k0, vcei_count
lw k1, (k0)
addiu k1, 1
sw k1, (k0)
#endif
eret
.set pop
END(except_vec3_r4000)
__FINIT
.align 5 /* 32 byte rollback region */
LEAF(__r4k_wait)
.set push
.set noreorder
/* start of rollback region */
LONG_L t0, TI_FLAGS($28)
nop
andi t0, _TIF_NEED_RESCHED
bnez t0, 1f
nop
nop
nop
#ifdef CONFIG_CPU_MICROMIPS
nop
nop
nop
nop
#endif
.set MIPS_ISA_ARCH_LEVEL_RAW
wait
/* end of rollback region (the region size must be power of two) */
1:
jr ra
nop
.set pop
END(__r4k_wait)
.macro BUILD_ROLLBACK_PROLOGUE handler
FEXPORT(rollback_\handler)
.set push
.set noat
MFC0 k0, CP0_EPC
PTR_LA k1, __r4k_wait
ori k0, 0x1f /* 32 byte rollback region */
xori k0, 0x1f
bne k0, k1, \handler
MTC0 k0, CP0_EPC
.set pop
.endm
.align 5
BUILD_ROLLBACK_PROLOGUE handle_int
NESTED(handle_int, PT_SIZE, sp)
.cfi_signal_frame
#ifdef CONFIG_TRACE_IRQFLAGS
/*
* Check to see if the interrupted code has just disabled
* interrupts and ignore this interrupt for now if so.
*
* local_irq_disable() disables interrupts and then calls
* trace_hardirqs_off() to track the state. If an interrupt is taken
* after interrupts are disabled but before the state is updated
* it will appear to restore_all that it is incorrectly returning with
* interrupts disabled
*/
.set push
.set noat
mfc0 k0, CP0_STATUS
#if defined(CONFIG_CPU_R3000)
and k0, ST0_IEP
bnez k0, 1f
mfc0 k0, CP0_EPC
.set noreorder
j k0
rfe
#else
and k0, ST0_IE
bnez k0, 1f
eret
#endif
1:
.set pop
#endif
SAVE_ALL docfi=1
CLI
TRACE_IRQS_OFF
LONG_L s0, TI_REGS($28)
LONG_S sp, TI_REGS($28)
/*
* SAVE_ALL ensures we are using a valid kernel stack for the thread.
* Check if we are already using the IRQ stack.
*/
move s1, sp # Preserve the sp
/* Get IRQ stack for this CPU */
ASM_CPUID_MFC0 k0, ASM_SMP_CPUID_REG
#if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
lui k1, %hi(irq_stack)
#else
lui k1, %highest(irq_stack)
daddiu k1, %higher(irq_stack)
dsll k1, 16
daddiu k1, %hi(irq_stack)
dsll k1, 16
#endif
LONG_SRL k0, SMP_CPUID_PTRSHIFT
LONG_ADDU k1, k0
LONG_L t0, %lo(irq_stack)(k1)
# Check if already on IRQ stack
PTR_LI t1, ~(_THREAD_SIZE-1)
and t1, t1, sp
beq t0, t1, 2f
/* Switch to IRQ stack */
li t1, _IRQ_STACK_START
PTR_ADD sp, t0, t1
/* Save task's sp on IRQ stack so that unwinding can follow it */
LONG_S s1, 0(sp)
2:
jal plat_irq_dispatch
/* Restore sp */
move sp, s1
j ret_from_irq
#ifdef CONFIG_CPU_MICROMIPS
nop
#endif
END(handle_int)
__INIT
/*
* Special interrupt vector for MIPS64 ISA & embedded MIPS processors.
* This is a dedicated interrupt exception vector which reduces the
* interrupt processing overhead. The jump instruction will be replaced
* at the initialization time.
*
* Be careful when changing this, it has to be at most 128 bytes
* to fit into space reserved for the exception handler.
*/
NESTED(except_vec4, 0, sp)
1: j 1b /* Dummy, will be replaced */
END(except_vec4)
/*
* EJTAG debug exception handler.
* The EJTAG debug exception entry point is 0xbfc00480, which
* normally is in the boot PROM, so the boot PROM must do an
* unconditional jump to this vector.
*/
NESTED(except_vec_ejtag_debug, 0, sp)
j ejtag_debug_handler
#ifdef CONFIG_CPU_MICROMIPS
nop
#endif
END(except_vec_ejtag_debug)
__FINIT
/*
* Vectored interrupt handler.
* This prototype is copied to ebase + n*IntCtl.VS and patched
* to invoke the handler
*/
BUILD_ROLLBACK_PROLOGUE except_vec_vi
NESTED(except_vec_vi, 0, sp)
SAVE_SOME docfi=1
SAVE_AT docfi=1
.set push
.set noreorder
PTR_LA v1, except_vec_vi_handler
FEXPORT(except_vec_vi_lui)
lui v0, 0 /* Patched */
jr v1
FEXPORT(except_vec_vi_ori)
ori v0, 0 /* Patched */
.set pop
END(except_vec_vi)
EXPORT(except_vec_vi_end)
/*
* Common Vectored Interrupt code
* Complete the register saves and invoke the handler which is passed in $v0
*/
NESTED(except_vec_vi_handler, 0, sp)
SAVE_TEMP
SAVE_STATIC
CLI
#ifdef CONFIG_TRACE_IRQFLAGS
move s0, v0
TRACE_IRQS_OFF
move v0, s0
#endif
LONG_L s0, TI_REGS($28)
LONG_S sp, TI_REGS($28)
/*
* SAVE_ALL ensures we are using a valid kernel stack for the thread.
* Check if we are already using the IRQ stack.
*/
move s1, sp # Preserve the sp
/* Get IRQ stack for this CPU */
ASM_CPUID_MFC0 k0, ASM_SMP_CPUID_REG
#if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
lui k1, %hi(irq_stack)
#else
lui k1, %highest(irq_stack)
daddiu k1, %higher(irq_stack)
dsll k1, 16
daddiu k1, %hi(irq_stack)
dsll k1, 16
#endif
LONG_SRL k0, SMP_CPUID_PTRSHIFT
LONG_ADDU k1, k0
LONG_L t0, %lo(irq_stack)(k1)
# Check if already on IRQ stack
PTR_LI t1, ~(_THREAD_SIZE-1)
and t1, t1, sp
beq t0, t1, 2f
/* Switch to IRQ stack */
li t1, _IRQ_STACK_START
PTR_ADD sp, t0, t1
/* Save task's sp on IRQ stack so that unwinding can follow it */
LONG_S s1, 0(sp)
2:
jalr v0
/* Restore sp */
move sp, s1
j ret_from_irq
END(except_vec_vi_handler)
/*
* EJTAG debug exception handler.
*/
NESTED(ejtag_debug_handler, PT_SIZE, sp)
.set push
.set noat
MTC0 k0, CP0_DESAVE
mfc0 k0, CP0_DEBUG
andi k0, k0, MIPS_DEBUG_DBP # Check for SDBBP.
beqz k0, ejtag_return
#ifdef CONFIG_SMP
1: PTR_LA k0, ejtag_debug_buffer_spinlock
__SYNC(full, loongson3_war)
2: ll k0, 0(k0)
bnez k0, 2b
PTR_LA k0, ejtag_debug_buffer_spinlock
sc k0, 0(k0)
beqz k0, 1b
# ifdef CONFIG_WEAK_REORDERING_BEYOND_LLSC
sync
# endif
PTR_LA k0, ejtag_debug_buffer
LONG_S k1, 0(k0)
ASM_CPUID_MFC0 k1, ASM_SMP_CPUID_REG
PTR_SRL k1, SMP_CPUID_PTRSHIFT
PTR_SLL k1, LONGLOG
PTR_LA k0, ejtag_debug_buffer_per_cpu
PTR_ADDU k0, k1
PTR_LA k1, ejtag_debug_buffer
LONG_L k1, 0(k1)
LONG_S k1, 0(k0)
PTR_LA k0, ejtag_debug_buffer_spinlock
sw zero, 0(k0)
#else
PTR_LA k0, ejtag_debug_buffer
LONG_S k1, 0(k0)
#endif
SAVE_ALL
move a0, sp
jal ejtag_exception_handler
RESTORE_ALL
#ifdef CONFIG_SMP
ASM_CPUID_MFC0 k1, ASM_SMP_CPUID_REG
PTR_SRL k1, SMP_CPUID_PTRSHIFT
PTR_SLL k1, LONGLOG
PTR_LA k0, ejtag_debug_buffer_per_cpu
PTR_ADDU k0, k1
LONG_L k1, 0(k0)
#else
PTR_LA k0, ejtag_debug_buffer
LONG_L k1, 0(k0)
#endif
ejtag_return:
back_to_back_c0_hazard
MFC0 k0, CP0_DESAVE
.set mips32
deret
.set pop
END(ejtag_debug_handler)
/*
* This buffer is reserved for the use of the EJTAG debug
* handler.
*/
.data
EXPORT(ejtag_debug_buffer)
.fill LONGSIZE
#ifdef CONFIG_SMP
EXPORT(ejtag_debug_buffer_spinlock)
.fill LONGSIZE
EXPORT(ejtag_debug_buffer_per_cpu)
.fill LONGSIZE * NR_CPUS
#endif
.previous
__INIT
/*
* NMI debug exception handler for MIPS reference boards.
* The NMI debug exception entry point is 0xbfc00000, which
* normally is in the boot PROM, so the boot PROM must do a
* unconditional jump to this vector.
*/
NESTED(except_vec_nmi, 0, sp)
j nmi_handler
#ifdef CONFIG_CPU_MICROMIPS
nop
#endif
END(except_vec_nmi)
__FINIT
NESTED(nmi_handler, PT_SIZE, sp)
.cfi_signal_frame
.set push
.set noat
/*
* Clear ERL - restore segment mapping
* Clear BEV - required for page fault exception handler to work
*/
mfc0 k0, CP0_STATUS
ori k0, k0, ST0_EXL
li k1, ~(ST0_BEV | ST0_ERL)
and k0, k0, k1
mtc0 k0, CP0_STATUS
_ehb
SAVE_ALL
move a0, sp
jal nmi_exception_handler
/* nmi_exception_handler never returns */
.set pop
END(nmi_handler)
.macro __build_clear_none
.endm
.macro __build_clear_sti
TRACE_IRQS_ON
STI
.endm
.macro __build_clear_cli
CLI
TRACE_IRQS_OFF
.endm
.macro __build_clear_fpe
CLI
TRACE_IRQS_OFF
.set push
/* gas fails to assemble cfc1 for some archs (octeon).*/ \
.set mips1
.set hardfloat
cfc1 a1, fcr31
.set pop
.endm
.macro __build_clear_msa_fpe
CLI
TRACE_IRQS_OFF
_cfcmsa a1, MSA_CSR
.endm
.macro __build_clear_ade
MFC0 t0, CP0_BADVADDR
PTR_S t0, PT_BVADDR(sp)
KMODE
.endm
.macro __build_clear_gsexc
.set push
/*
* We need to specify a selector to access the CP0.Diag1 (GSCause)
* register. All GSExc-equipped processors have MIPS32.
*/
.set mips32
mfc0 a1, CP0_DIAGNOSTIC1
.set pop
TRACE_IRQS_ON
STI
.endm
.macro __BUILD_silent exception
.endm
/* Gas tries to parse the ASM_PRINT argument as a string containing
string escapes and emits bogus warnings if it believes to
recognize an unknown escape code. So make the arguments
start with an n and gas will believe \n is ok ... */
.macro __BUILD_verbose nexception
LONG_L a1, PT_EPC(sp)
#ifdef CONFIG_32BIT
ASM_PRINT("Got \nexception at %08lx\012")
#endif
#ifdef CONFIG_64BIT
ASM_PRINT("Got \nexception at %016lx\012")
#endif
.endm
.macro __BUILD_count exception
LONG_L t0,exception_count_\exception
LONG_ADDIU t0, 1
LONG_S t0,exception_count_\exception
.comm exception_count\exception, 8, 8
.endm
.macro __BUILD_HANDLER exception handler clear verbose ext
.align 5
NESTED(handle_\exception, PT_SIZE, sp)
.cfi_signal_frame
.set noat
SAVE_ALL
FEXPORT(handle_\exception\ext)
__build_clear_\clear
.set at
__BUILD_\verbose \exception
move a0, sp
jal do_\handler
j ret_from_exception
END(handle_\exception)
.endm
.macro BUILD_HANDLER exception handler clear verbose
__BUILD_HANDLER \exception \handler \clear \verbose _int
.endm
BUILD_HANDLER adel ade ade silent /* #4 */
BUILD_HANDLER ades ade ade silent /* #5 */
BUILD_HANDLER ibe be cli silent /* #6 */
BUILD_HANDLER dbe be cli silent /* #7 */
BUILD_HANDLER bp bp sti silent /* #9 */
BUILD_HANDLER ri ri sti silent /* #10 */
BUILD_HANDLER cpu cpu sti silent /* #11 */
BUILD_HANDLER ov ov sti silent /* #12 */
BUILD_HANDLER tr tr sti silent /* #13 */
BUILD_HANDLER msa_fpe msa_fpe msa_fpe silent /* #14 */
#ifdef CONFIG_MIPS_FP_SUPPORT
BUILD_HANDLER fpe fpe fpe silent /* #15 */
#endif
BUILD_HANDLER ftlb ftlb none silent /* #16 */
BUILD_HANDLER gsexc gsexc gsexc silent /* #16 */
BUILD_HANDLER msa msa sti silent /* #21 */
BUILD_HANDLER mdmx mdmx sti silent /* #22 */
#ifdef CONFIG_HARDWARE_WATCHPOINTS
/*
* For watch, interrupts will be enabled after the watch
* registers are read.
*/
BUILD_HANDLER watch watch cli silent /* #23 */
#else
BUILD_HANDLER watch watch sti verbose /* #23 */
#endif
BUILD_HANDLER mcheck mcheck cli verbose /* #24 */
BUILD_HANDLER mt mt sti silent /* #25 */
BUILD_HANDLER dsp dsp sti silent /* #26 */
BUILD_HANDLER reserved reserved sti verbose /* others */
.align 5
LEAF(handle_ri_rdhwr_tlbp)
.set push
.set noat
.set noreorder
/* check if TLB contains a entry for EPC */
MFC0 k1, CP0_ENTRYHI
andi k1, MIPS_ENTRYHI_ASID | MIPS_ENTRYHI_ASIDX
MFC0 k0, CP0_EPC
PTR_SRL k0, _PAGE_SHIFT + 1
PTR_SLL k0, _PAGE_SHIFT + 1
or k1, k0
MTC0 k1, CP0_ENTRYHI
mtc0_tlbw_hazard
tlbp
tlb_probe_hazard
mfc0 k1, CP0_INDEX
.set pop
bltz k1, handle_ri /* slow path */
/* fall thru */
END(handle_ri_rdhwr_tlbp)
LEAF(handle_ri_rdhwr)
.set push
.set noat
.set noreorder
/* MIPS32: 0x7c03e83b: rdhwr v1,$29 */
/* microMIPS: 0x007d6b3c: rdhwr v1,$29 */
MFC0 k1, CP0_EPC
#if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_MIPS32_R2) || defined(CONFIG_CPU_MIPS64_R2)
and k0, k1, 1
beqz k0, 1f
xor k1, k0
lhu k0, (k1)
lhu k1, 2(k1)
ins k1, k0, 16, 16
lui k0, 0x007d
b docheck
ori k0, 0x6b3c
1:
lui k0, 0x7c03
lw k1, (k1)
ori k0, 0xe83b
#else
andi k0, k1, 1
bnez k0, handle_ri
lui k0, 0x7c03
lw k1, (k1)
ori k0, 0xe83b
#endif
.set reorder
docheck:
bne k0, k1, handle_ri /* if not ours */
isrdhwr:
/* The insn is rdhwr. No need to check CAUSE.BD here. */
get_saved_sp /* k1 := current_thread_info */
.set noreorder
MFC0 k0, CP0_EPC
#if defined(CONFIG_CPU_R3000)
ori k1, _THREAD_MASK
xori k1, _THREAD_MASK
LONG_L v1, TI_TP_VALUE(k1)
LONG_ADDIU k0, 4
jr k0
rfe
#else
#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
LONG_ADDIU k0, 4 /* stall on $k0 */
#else
.set at=v1
LONG_ADDIU k0, 4
.set noat
#endif
MTC0 k0, CP0_EPC
/* I hope three instructions between MTC0 and ERET are enough... */
ori k1, _THREAD_MASK
xori k1, _THREAD_MASK
LONG_L v1, TI_TP_VALUE(k1)
.set push
.set arch=r4000
eret
.set pop
#endif
.set pop
END(handle_ri_rdhwr)
#ifdef CONFIG_CPU_R4X00_BUGS64
/* A temporary overflow handler used by check_daddi(). */
__INIT
BUILD_HANDLER daddi_ov daddi_ov none silent /* #12 */
#endif