/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 2005-2011. All Rights Reserved.
*
* The contents of this file are subject to the Erlang Public License,
* Version 1.1, (the "License"); you may not use this file except in
* compliance with the License. You should have received a copy of the
* Erlang Public License along with this software. If not, it can be
* retrieved online at http://www.erlang.org/.
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and limitations
* under the License.
*
* %CopyrightEnd%
*/
#define ASM
#include "hipe_arm_asm.h"
#include "hipe_literals.h"
#include "hipe_mode_switch.h"
.text
.p2align 2
/*
* Enter Erlang from C.
* Create a new frame on the C stack.
* Save C callee-save registers in the frame.
* Do not clobber the C argument registers.
* Retrieve the process pointer from the C argument registers.
*
* Our C frame includes:
* - 9*4 == 36 bytes for saving r4-r11 and lr
* - 2*4 == 8 bytes for calls to hipe_bs_put_{big_integer,small_float}.
* They take 5-6 parameter words: 4 in registers and 1-2 on the stack.
* (They take 5 regular parameters, and an additional P parameter on SMP.)
* - 4 bytes to pad the frame size to a multiple of 8
*/
#define ENTER_FROM_C \
stmfd sp!, {r4,r5,r6,r7,r8,r9,r10,r11,lr}; \
sub sp, sp, #12; \
mov P, r0; \
RESTORE_CACHED_STATE
/*
* Return to the calling C function.
* The return value is in r0.
*
* .nosave_exit saves no state
* .flush_exit saves NSP and other cached P state.
* .suspend_exit also saves RA.
*/
.suspend_exit:
/* save RA, so we can be resumed */
str lr, [P, #P_NRA]
.flush_exit:
/* flush cached P state */
SAVE_CACHED_STATE
.nosave_exit:
/* restore callee-save registers, drop frame, return */
add sp, sp, #12
ldmfd sp!, {r4,r5,r6,r7,r8,r9,r10,r11,pc}
/*
* int hipe_arm_call_to_native(Process *p);
* Emulated code recursively calls native code.
*/
.global hipe_arm_call_to_native
hipe_arm_call_to_native:
ENTER_FROM_C
/* get argument registers */
LOAD_ARG_REGS
/* call the target */
mov lr, pc
ldr pc, [P, #P_NCALLEE]
/* FALLTHROUGH
*
* We export this return address so that hipe_mode_switch() can discover
* when native code tailcalls emulated code.
*
* This is where native code returns to emulated code.
*/
.global nbif_return
nbif_return:
str r0, [P, #P_ARG0] /* save retval */
mov r0, #HIPE_MODE_SWITCH_RES_RETURN
b .flush_exit
/*
* int hipe_arm_return_to_native(Process *p);
* Emulated code returns to its native code caller.
*/
.global hipe_arm_return_to_native
hipe_arm_return_to_native:
ENTER_FROM_C
/* get return value */
ldr r0, [P, #P_ARG0]
/*
* Return using the current return address.
* The parameters were popped at the original native-to-emulated
* call (hipe_call_from_native_is_recursive), so a plain ret suffices.
*/
ldr pc, [P, #P_NRA]
/*
* int hipe_arm_tailcall_to_native(Process *p);
* Emulated code tailcalls native code.
*/
.global hipe_arm_tailcall_to_native
hipe_arm_tailcall_to_native:
ENTER_FROM_C
/* get argument registers */
LOAD_ARG_REGS
/* restore return address */
ldr lr, [P, #P_NRA]
/* call the target */
ldr pc, [P, #P_NCALLEE]
/*
* int hipe_arm_throw_to_native(Process *p);
* Emulated code throws an exception to its native code caller.
*/
.global hipe_arm_throw_to_native
hipe_arm_throw_to_native:
ENTER_FROM_C
/* invoke the handler */
ldr pc, [P, #P_NCALLEE] /* set by hipe_find_handler() */
/*
* Native code calls emulated code via a stub
* which should look as follows:
*
* stub for f/N:
* <set r8 to f's export entry address>
* <set r0 to N>
* b nbif_callemu
*
* XXX: Different stubs for different number of register parameters?
*/
.global nbif_callemu
nbif_callemu:
str r8, [P, #P_CALLEE_EXP]
str r0, [P, #P_ARITY]
STORE_ARG_REGS
mov r0, #HIPE_MODE_SWITCH_RES_CALL_EXPORTED
b .suspend_exit
/*
* nbif_apply
*/
.global nbif_apply
nbif_apply:
STORE_ARG_REGS
mov r0, #HIPE_MODE_SWITCH_RES_APPLY
b .suspend_exit
/*
* Native code calls an emulated-mode closure via a stub defined below.
*
* The closure is appended as the last actual parameter, and parameters
* beyond the first few passed in registers are pushed onto the stack in
* left-to-right order.
* Hence, the location of the closure parameter only depends on the number
* of parameters in registers, not the total number of parameters.
*/
#if NR_ARG_REGS >= 6
.global nbif_ccallemu6
nbif_ccallemu6:
str ARG5, [P, #P_ARG5]
#if NR_ARG_REGS > 6
mov ARG5, ARG6
#else
ldr ARG5, [NSP, #0]
#endif
/*FALLTHROUGH*/
#endif
#if NR_ARG_REGS >= 5
.global nbif_ccallemu5
nbif_ccallemu5:
str ARG4, [P, #P_ARG4]
#if NR_ARG_REGS > 5
mov ARG4, ARG5
#else
ldr ARG4, [NSP, #0]
#endif
/*FALLTHROUGH*/
#endif
#if NR_ARG_REGS >= 4
.global nbif_ccallemu4
nbif_ccallemu4:
str ARG3, [P, #P_ARG3]
#if NR_ARG_REGS > 4
mov ARG3, ARG4
#else
ldr ARG3, [NSP, #0]
#endif
/*FALLTHROUGH*/
#endif
#if NR_ARG_REGS >= 3
.global nbif_ccallemu3
nbif_ccallemu3:
str ARG2, [P, #P_ARG2]
#if NR_ARG_REGS > 3
mov ARG2, ARG3
#else
ldr ARG2, [NSP, #0]
#endif
/*FALLTHROUGH*/
#endif
#if NR_ARG_REGS >= 2
.global nbif_ccallemu2
nbif_ccallemu2:
str ARG1, [P, #P_ARG1]
#if NR_ARG_REGS > 2
mov ARG1, ARG2
#else
ldr ARG1, [NSP, #0]
#endif
/*FALLTHROUGH*/
#endif
#if NR_ARG_REGS >= 1
.global nbif_ccallemu1
nbif_ccallemu1:
str ARG0, [P, #P_ARG0]
#if NR_ARG_REGS > 1
mov ARG0, ARG1
#else
ldr ARG0, [NSP, #0]
#endif
/*FALLTHROUGH*/
#endif
.global nbif_ccallemu0
nbif_ccallemu0:
/* We use r1 not ARG0 here because ARG0 is not
defined when NR_ARG_REGS == 0. */
#if NR_ARG_REGS == 0
ldr r1, [NSP, #0] /* get the closure */
#endif
str r1, [P, #P_CLOSURE] /* save the closure */
mov r0, #HIPE_MODE_SWITCH_RES_CALL_CLOSURE
b .suspend_exit
/*
* This is where native code suspends.
*/
.global nbif_suspend_0
nbif_suspend_0:
mov r0, #HIPE_MODE_SWITCH_RES_SUSPEND
b .suspend_exit
/*
* Suspend from a receive (waiting for a message)
*/
.global nbif_suspend_msg
nbif_suspend_msg:
mov r0, #HIPE_MODE_SWITCH_RES_WAIT
b .suspend_exit
/*
* Suspend from a receive with a timeout (waiting for a message)
* if (!(p->flags & F_TIMO)) { suspend }
* else { return 0; }
*/
.global nbif_suspend_msg_timeout
nbif_suspend_msg_timeout:
ldr r1, [P, #P_FLAGS]
mov r0, #HIPE_MODE_SWITCH_RES_WAIT_TIMEOUT
/* this relies on F_TIMO (1<<2) fitting in a uimm16 */
tst r1, #F_TIMO
beq .suspend_exit
/* timeout has occurred */
mov r0, #0
mov pc, lr
/*
* This is the default exception handler for native code.
*/
.global nbif_fail
nbif_fail:
mov r0, #HIPE_MODE_SWITCH_RES_THROW
b .flush_exit /* no need to save RA */
.global nbif_0_gc_after_bif
.global nbif_1_gc_after_bif
.global nbif_2_gc_after_bif
.global nbif_3_gc_after_bif
nbif_0_gc_after_bif:
mov r1, #0
b .gc_after_bif
nbif_1_gc_after_bif:
mov r1, #1
b .gc_after_bif
nbif_2_gc_after_bif:
mov r1, #2
b .gc_after_bif
nbif_3_gc_after_bif:
mov r1, #3
/*FALLTHROUGH*/
.gc_after_bif:
str r1, [P, #P_NARITY]
str TEMP_LR, [P, #P_NRA]
str NSP, [P, #P_NSP]
mov TEMP_LR, lr
mov r3, #0 /* Pass 0 in arity */
mov r2, #0 /* Pass NULL in regs */
mov r1, r0
mov r0, P
bl erts_gc_after_bif_call
mov lr, TEMP_LR
ldr TEMP_LR, [P, #P_NRA]
mov r1, #0
str r1, [P, #P_NARITY]
mov pc, lr
/*
* We end up here when a BIF called from native signals an
* exceptional condition.
* HP was just read from P.
* NSP has not been saved in P.
* TEMP_LR contains a copy of LR
*/
.global nbif_0_simple_exception
nbif_0_simple_exception:
mov r1, #0
b .nbif_simple_exception
.global nbif_1_simple_exception
nbif_1_simple_exception:
mov r1, #1
b .nbif_simple_exception
.global nbif_2_simple_exception
nbif_2_simple_exception:
mov r1, #2
b .nbif_simple_exception
.global nbif_3_simple_exception
nbif_3_simple_exception:
mov r1, #3
/*FALLTHROUGH*/
.nbif_simple_exception:
ldr r0, [P, #P_FREASON]
cmp r0, #FREASON_TRAP
beq .handle_trap
/*
* Find and invoke catch handler (it must exist).
* HP was just read from P.
* NSP has not been saved in P.
* TEMP_LR should contain the current call's return address.
* r1 should contain the current call's arity.
*/
str NSP, [P, #P_NSP]
str TEMP_LR, [P, #P_NRA]
str r1, [P, #P_NARITY]
/* find and prepare to invoke the handler */
mov r0, P
bl hipe_handle_exception /* Note: hipe_handle_exception() conses */
RESTORE_CACHED_STATE /* NSP updated by hipe_find_handler() */
/* now invoke the handler */
ldr pc, [P, #P_NCALLEE] /* set by hipe_find_handler() */
/*
* A BIF failed with freason TRAP:
* - the BIF's arity is in r1
* - the native RA was saved in TEMP_LR before the BIF call
* - HP was just read from P
* - NSP has not been saved in P
*/
.handle_trap:
mov r0, #HIPE_MODE_SWITCH_RES_TRAP
str NSP, [P, #P_NSP]
str r1, [P, #P_NARITY]
str TEMP_LR, [P, #P_NRA]
b .nosave_exit
/*
* nbif_stack_trap_ra: trap return address for maintaining
* the gray/white stack boundary
*/
.global nbif_stack_trap_ra
nbif_stack_trap_ra: /* a return address, not a function */
# This only handles a single return value.
# If we have more, we need to save them in the PCB.
mov TEMP_ARG0, r0 /* save retval */
str NSP, [P, #P_NSP]
mov r0, P
bl hipe_handle_stack_trap /* must not cons */
mov lr, r0 /* original RA */
mov r0, TEMP_ARG0 /* restore retval */
mov pc, lr /* resume at original RA */
/*
* hipe_arm_inc_stack
* Caller saved its LR in TEMP_LR (== TEMP1) before calling us.
*/
.global hipe_arm_inc_stack
hipe_arm_inc_stack:
STORE_ARG_REGS
mov TEMP_ARG0, lr
str NSP, [P, #P_NSP]
mov r0, P
# hipe_inc_nstack reads and writes NSP and NSP_LIMIT,
# but does not access LR/RA, HP, or FCALLS.
bl hipe_inc_nstack
ldr NSP, [P, #P_NSP]
LOAD_ARG_REGS
# this relies on LOAD_ARG_REGS not clobbering TEMP_ARG0
mov pc, TEMP_ARG0
#if defined(__linux__) && defined(__ELF__)
.section .note.GNU-stack,"",%progbits
#endif
