854 lines
18 KiB
ArmAsm
854 lines
18 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* arch/alpha/kernel/entry.S
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*
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* Kernel entry-points.
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*/
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#include <asm/asm-offsets.h>
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#include <asm/thread_info.h>
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#include <asm/pal.h>
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#include <asm/errno.h>
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#include <asm/unistd.h>
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.text
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.set noat
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.cfi_sections .debug_frame
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/* Stack offsets. */
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#define SP_OFF 184
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#define SWITCH_STACK_SIZE 64
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.macro CFI_START_OSF_FRAME func
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.align 4
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.globl \func
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.type \func,@function
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\func:
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.cfi_startproc simple
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.cfi_return_column 64
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.cfi_def_cfa $sp, 48
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.cfi_rel_offset 64, 8
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.cfi_rel_offset $gp, 16
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.cfi_rel_offset $16, 24
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.cfi_rel_offset $17, 32
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.cfi_rel_offset $18, 40
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.endm
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.macro CFI_END_OSF_FRAME func
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.cfi_endproc
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.size \func, . - \func
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.endm
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/*
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* This defines the normal kernel pt-regs layout.
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*
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* regs 9-15 preserved by C code
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* regs 16-18 saved by PAL-code
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* regs 29-30 saved and set up by PAL-code
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* JRP - Save regs 16-18 in a special area of the stack, so that
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* the palcode-provided values are available to the signal handler.
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*/
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.macro SAVE_ALL
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subq $sp, SP_OFF, $sp
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.cfi_adjust_cfa_offset SP_OFF
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stq $0, 0($sp)
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stq $1, 8($sp)
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stq $2, 16($sp)
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stq $3, 24($sp)
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stq $4, 32($sp)
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stq $28, 144($sp)
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.cfi_rel_offset $0, 0
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.cfi_rel_offset $1, 8
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.cfi_rel_offset $2, 16
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.cfi_rel_offset $3, 24
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.cfi_rel_offset $4, 32
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.cfi_rel_offset $28, 144
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lda $2, alpha_mv
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stq $5, 40($sp)
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stq $6, 48($sp)
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stq $7, 56($sp)
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stq $8, 64($sp)
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stq $19, 72($sp)
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stq $20, 80($sp)
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stq $21, 88($sp)
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ldq $2, HAE_CACHE($2)
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stq $22, 96($sp)
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stq $23, 104($sp)
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stq $24, 112($sp)
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stq $25, 120($sp)
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stq $26, 128($sp)
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stq $27, 136($sp)
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stq $2, 152($sp)
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stq $16, 160($sp)
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stq $17, 168($sp)
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stq $18, 176($sp)
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.cfi_rel_offset $5, 40
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.cfi_rel_offset $6, 48
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.cfi_rel_offset $7, 56
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.cfi_rel_offset $8, 64
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.cfi_rel_offset $19, 72
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.cfi_rel_offset $20, 80
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.cfi_rel_offset $21, 88
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.cfi_rel_offset $22, 96
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.cfi_rel_offset $23, 104
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.cfi_rel_offset $24, 112
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.cfi_rel_offset $25, 120
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.cfi_rel_offset $26, 128
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.cfi_rel_offset $27, 136
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.endm
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.macro RESTORE_ALL
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lda $19, alpha_mv
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ldq $0, 0($sp)
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ldq $1, 8($sp)
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ldq $2, 16($sp)
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ldq $3, 24($sp)
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ldq $21, 152($sp)
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ldq $20, HAE_CACHE($19)
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ldq $4, 32($sp)
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ldq $5, 40($sp)
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ldq $6, 48($sp)
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ldq $7, 56($sp)
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subq $20, $21, $20
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ldq $8, 64($sp)
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beq $20, 99f
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ldq $20, HAE_REG($19)
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stq $21, HAE_CACHE($19)
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stq $21, 0($20)
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99: ldq $19, 72($sp)
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ldq $20, 80($sp)
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ldq $21, 88($sp)
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ldq $22, 96($sp)
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ldq $23, 104($sp)
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ldq $24, 112($sp)
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ldq $25, 120($sp)
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ldq $26, 128($sp)
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ldq $27, 136($sp)
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ldq $28, 144($sp)
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addq $sp, SP_OFF, $sp
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.cfi_restore $0
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.cfi_restore $1
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.cfi_restore $2
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.cfi_restore $3
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.cfi_restore $4
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.cfi_restore $5
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.cfi_restore $6
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.cfi_restore $7
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.cfi_restore $8
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.cfi_restore $19
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.cfi_restore $20
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.cfi_restore $21
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.cfi_restore $22
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.cfi_restore $23
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.cfi_restore $24
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.cfi_restore $25
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.cfi_restore $26
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.cfi_restore $27
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.cfi_restore $28
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.cfi_adjust_cfa_offset -SP_OFF
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.endm
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.macro DO_SWITCH_STACK
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bsr $1, do_switch_stack
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.cfi_adjust_cfa_offset SWITCH_STACK_SIZE
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.cfi_rel_offset $9, 0
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.cfi_rel_offset $10, 8
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.cfi_rel_offset $11, 16
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.cfi_rel_offset $12, 24
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.cfi_rel_offset $13, 32
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.cfi_rel_offset $14, 40
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.cfi_rel_offset $15, 48
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.endm
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.macro UNDO_SWITCH_STACK
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bsr $1, undo_switch_stack
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.cfi_restore $9
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.cfi_restore $10
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.cfi_restore $11
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.cfi_restore $12
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.cfi_restore $13
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.cfi_restore $14
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.cfi_restore $15
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.cfi_adjust_cfa_offset -SWITCH_STACK_SIZE
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.endm
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/*
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* Non-syscall kernel entry points.
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*/
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CFI_START_OSF_FRAME entInt
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SAVE_ALL
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lda $8, 0x3fff
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lda $26, ret_from_sys_call
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bic $sp, $8, $8
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mov $sp, $19
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jsr $31, do_entInt
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CFI_END_OSF_FRAME entInt
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CFI_START_OSF_FRAME entArith
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SAVE_ALL
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lda $8, 0x3fff
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lda $26, ret_from_sys_call
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bic $sp, $8, $8
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mov $sp, $18
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jsr $31, do_entArith
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CFI_END_OSF_FRAME entArith
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CFI_START_OSF_FRAME entMM
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SAVE_ALL
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/* save $9 - $15 so the inline exception code can manipulate them. */
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subq $sp, 56, $sp
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.cfi_adjust_cfa_offset 56
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stq $9, 0($sp)
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stq $10, 8($sp)
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stq $11, 16($sp)
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stq $12, 24($sp)
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stq $13, 32($sp)
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stq $14, 40($sp)
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stq $15, 48($sp)
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.cfi_rel_offset $9, 0
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.cfi_rel_offset $10, 8
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.cfi_rel_offset $11, 16
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.cfi_rel_offset $12, 24
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.cfi_rel_offset $13, 32
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.cfi_rel_offset $14, 40
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.cfi_rel_offset $15, 48
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addq $sp, 56, $19
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/* handle the fault */
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lda $8, 0x3fff
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bic $sp, $8, $8
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jsr $26, do_page_fault
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/* reload the registers after the exception code played. */
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ldq $9, 0($sp)
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ldq $10, 8($sp)
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ldq $11, 16($sp)
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ldq $12, 24($sp)
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ldq $13, 32($sp)
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ldq $14, 40($sp)
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ldq $15, 48($sp)
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addq $sp, 56, $sp
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.cfi_restore $9
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.cfi_restore $10
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.cfi_restore $11
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.cfi_restore $12
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.cfi_restore $13
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.cfi_restore $14
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.cfi_restore $15
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.cfi_adjust_cfa_offset -56
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/* finish up the syscall as normal. */
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br ret_from_sys_call
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CFI_END_OSF_FRAME entMM
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CFI_START_OSF_FRAME entIF
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SAVE_ALL
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lda $8, 0x3fff
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lda $26, ret_from_sys_call
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bic $sp, $8, $8
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mov $sp, $17
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jsr $31, do_entIF
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CFI_END_OSF_FRAME entIF
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CFI_START_OSF_FRAME entUna
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lda $sp, -256($sp)
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.cfi_adjust_cfa_offset 256
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stq $0, 0($sp)
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.cfi_rel_offset $0, 0
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.cfi_remember_state
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ldq $0, 256($sp) /* get PS */
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stq $1, 8($sp)
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stq $2, 16($sp)
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stq $3, 24($sp)
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and $0, 8, $0 /* user mode? */
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stq $4, 32($sp)
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bne $0, entUnaUser /* yup -> do user-level unaligned fault */
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stq $5, 40($sp)
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stq $6, 48($sp)
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stq $7, 56($sp)
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stq $8, 64($sp)
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stq $9, 72($sp)
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stq $10, 80($sp)
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stq $11, 88($sp)
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stq $12, 96($sp)
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stq $13, 104($sp)
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stq $14, 112($sp)
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stq $15, 120($sp)
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/* 16-18 PAL-saved */
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stq $19, 152($sp)
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stq $20, 160($sp)
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stq $21, 168($sp)
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stq $22, 176($sp)
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stq $23, 184($sp)
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stq $24, 192($sp)
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stq $25, 200($sp)
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stq $26, 208($sp)
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stq $27, 216($sp)
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stq $28, 224($sp)
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mov $sp, $19
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stq $gp, 232($sp)
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.cfi_rel_offset $1, 1*8
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.cfi_rel_offset $2, 2*8
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.cfi_rel_offset $3, 3*8
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.cfi_rel_offset $4, 4*8
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.cfi_rel_offset $5, 5*8
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.cfi_rel_offset $6, 6*8
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.cfi_rel_offset $7, 7*8
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.cfi_rel_offset $8, 8*8
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.cfi_rel_offset $9, 9*8
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.cfi_rel_offset $10, 10*8
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.cfi_rel_offset $11, 11*8
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.cfi_rel_offset $12, 12*8
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.cfi_rel_offset $13, 13*8
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.cfi_rel_offset $14, 14*8
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.cfi_rel_offset $15, 15*8
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.cfi_rel_offset $19, 19*8
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.cfi_rel_offset $20, 20*8
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.cfi_rel_offset $21, 21*8
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.cfi_rel_offset $22, 22*8
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.cfi_rel_offset $23, 23*8
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.cfi_rel_offset $24, 24*8
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.cfi_rel_offset $25, 25*8
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.cfi_rel_offset $26, 26*8
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.cfi_rel_offset $27, 27*8
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.cfi_rel_offset $28, 28*8
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.cfi_rel_offset $29, 29*8
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lda $8, 0x3fff
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stq $31, 248($sp)
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bic $sp, $8, $8
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jsr $26, do_entUna
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ldq $0, 0($sp)
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ldq $1, 8($sp)
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ldq $2, 16($sp)
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ldq $3, 24($sp)
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ldq $4, 32($sp)
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ldq $5, 40($sp)
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ldq $6, 48($sp)
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ldq $7, 56($sp)
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ldq $8, 64($sp)
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ldq $9, 72($sp)
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ldq $10, 80($sp)
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ldq $11, 88($sp)
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ldq $12, 96($sp)
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ldq $13, 104($sp)
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ldq $14, 112($sp)
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ldq $15, 120($sp)
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/* 16-18 PAL-saved */
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ldq $19, 152($sp)
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ldq $20, 160($sp)
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ldq $21, 168($sp)
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ldq $22, 176($sp)
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ldq $23, 184($sp)
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ldq $24, 192($sp)
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ldq $25, 200($sp)
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ldq $26, 208($sp)
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ldq $27, 216($sp)
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ldq $28, 224($sp)
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ldq $gp, 232($sp)
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lda $sp, 256($sp)
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.cfi_restore $1
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.cfi_restore $2
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.cfi_restore $3
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.cfi_restore $4
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.cfi_restore $5
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.cfi_restore $6
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.cfi_restore $7
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.cfi_restore $8
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.cfi_restore $9
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.cfi_restore $10
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.cfi_restore $11
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.cfi_restore $12
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.cfi_restore $13
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.cfi_restore $14
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.cfi_restore $15
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.cfi_restore $19
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.cfi_restore $20
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.cfi_restore $21
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.cfi_restore $22
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.cfi_restore $23
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.cfi_restore $24
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.cfi_restore $25
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.cfi_restore $26
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.cfi_restore $27
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.cfi_restore $28
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.cfi_restore $29
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.cfi_adjust_cfa_offset -256
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call_pal PAL_rti
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.align 4
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entUnaUser:
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.cfi_restore_state
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ldq $0, 0($sp) /* restore original $0 */
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lda $sp, 256($sp) /* pop entUna's stack frame */
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.cfi_restore $0
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.cfi_adjust_cfa_offset -256
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SAVE_ALL /* setup normal kernel stack */
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lda $sp, -56($sp)
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.cfi_adjust_cfa_offset 56
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stq $9, 0($sp)
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stq $10, 8($sp)
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stq $11, 16($sp)
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stq $12, 24($sp)
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stq $13, 32($sp)
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stq $14, 40($sp)
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stq $15, 48($sp)
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.cfi_rel_offset $9, 0
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.cfi_rel_offset $10, 8
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.cfi_rel_offset $11, 16
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.cfi_rel_offset $12, 24
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.cfi_rel_offset $13, 32
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.cfi_rel_offset $14, 40
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.cfi_rel_offset $15, 48
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lda $8, 0x3fff
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addq $sp, 56, $19
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bic $sp, $8, $8
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jsr $26, do_entUnaUser
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ldq $9, 0($sp)
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ldq $10, 8($sp)
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ldq $11, 16($sp)
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ldq $12, 24($sp)
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ldq $13, 32($sp)
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ldq $14, 40($sp)
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ldq $15, 48($sp)
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lda $sp, 56($sp)
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.cfi_restore $9
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.cfi_restore $10
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.cfi_restore $11
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.cfi_restore $12
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.cfi_restore $13
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.cfi_restore $14
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.cfi_restore $15
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.cfi_adjust_cfa_offset -56
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br ret_from_sys_call
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CFI_END_OSF_FRAME entUna
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CFI_START_OSF_FRAME entDbg
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SAVE_ALL
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lda $8, 0x3fff
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lda $26, ret_from_sys_call
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bic $sp, $8, $8
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mov $sp, $16
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jsr $31, do_entDbg
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CFI_END_OSF_FRAME entDbg
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/*
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* The system call entry point is special. Most importantly, it looks
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* like a function call to userspace as far as clobbered registers. We
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* do preserve the argument registers (for syscall restarts) and $26
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* (for leaf syscall functions).
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*
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* So much for theory. We don't take advantage of this yet.
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*
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* Note that a0-a2 are not saved by PALcode as with the other entry points.
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*/
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.align 4
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.globl entSys
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.type entSys, @function
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.cfi_startproc simple
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.cfi_return_column 64
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.cfi_def_cfa $sp, 48
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.cfi_rel_offset 64, 8
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.cfi_rel_offset $gp, 16
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entSys:
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SAVE_ALL
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lda $8, 0x3fff
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bic $sp, $8, $8
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lda $4, NR_syscalls($31)
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stq $16, SP_OFF+24($sp)
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lda $5, sys_call_table
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lda $27, sys_ni_syscall
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cmpult $0, $4, $4
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ldl $3, TI_FLAGS($8)
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stq $17, SP_OFF+32($sp)
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s8addq $0, $5, $5
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stq $18, SP_OFF+40($sp)
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.cfi_rel_offset $16, SP_OFF+24
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.cfi_rel_offset $17, SP_OFF+32
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.cfi_rel_offset $18, SP_OFF+40
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#ifdef CONFIG_AUDITSYSCALL
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lda $6, _TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT
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and $3, $6, $3
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bne $3, strace
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#else
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blbs $3, strace /* check for SYSCALL_TRACE in disguise */
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#endif
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beq $4, 1f
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ldq $27, 0($5)
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1: jsr $26, ($27), sys_ni_syscall
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ldgp $gp, 0($26)
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blt $0, $syscall_error /* the call failed */
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$ret_success:
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stq $0, 0($sp)
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stq $31, 72($sp) /* a3=0 => no error */
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.align 4
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.globl ret_from_sys_call
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ret_from_sys_call:
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cmovne $26, 0, $18 /* $18 = 0 => non-restartable */
|
||
ldq $0, SP_OFF($sp)
|
||
and $0, 8, $0
|
||
beq $0, ret_to_kernel
|
||
ret_to_user:
|
||
/* Make sure need_resched and sigpending don't change between
|
||
sampling and the rti. */
|
||
lda $16, 7
|
||
call_pal PAL_swpipl
|
||
ldl $17, TI_FLAGS($8)
|
||
and $17, _TIF_WORK_MASK, $2
|
||
bne $2, work_pending
|
||
restore_all:
|
||
ldl $2, TI_STATUS($8)
|
||
and $2, TS_SAVED_FP | TS_RESTORE_FP, $3
|
||
bne $3, restore_fpu
|
||
restore_other:
|
||
.cfi_remember_state
|
||
RESTORE_ALL
|
||
call_pal PAL_rti
|
||
|
||
ret_to_kernel:
|
||
.cfi_restore_state
|
||
lda $16, 7
|
||
call_pal PAL_swpipl
|
||
br restore_other
|
||
|
||
.align 3
|
||
$syscall_error:
|
||
/*
|
||
* Some system calls (e.g., ptrace) can return arbitrary
|
||
* values which might normally be mistaken as error numbers.
|
||
* Those functions must zero $0 (v0) directly in the stack
|
||
* frame to indicate that a negative return value wasn't an
|
||
* error number..
|
||
*/
|
||
ldq $18, 0($sp) /* old syscall nr (zero if success) */
|
||
beq $18, $ret_success
|
||
|
||
ldq $19, 72($sp) /* .. and this a3 */
|
||
subq $31, $0, $0 /* with error in v0 */
|
||
addq $31, 1, $1 /* set a3 for errno return */
|
||
stq $0, 0($sp)
|
||
mov $31, $26 /* tell "ret_from_sys_call" we can restart */
|
||
stq $1, 72($sp) /* a3 for return */
|
||
br ret_from_sys_call
|
||
|
||
/*
|
||
* Do all cleanup when returning from all interrupts and system calls.
|
||
*
|
||
* Arguments:
|
||
* $8: current.
|
||
* $17: TI_FLAGS.
|
||
* $18: The old syscall number, or zero if this is not a return
|
||
* from a syscall that errored and is possibly restartable.
|
||
* $19: The old a3 value
|
||
*/
|
||
|
||
.align 4
|
||
.type work_pending, @function
|
||
work_pending:
|
||
and $17, _TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL, $2
|
||
bne $2, $work_notifysig
|
||
|
||
$work_resched:
|
||
/*
|
||
* We can get here only if we returned from syscall without SIGPENDING
|
||
* or got through work_notifysig already. Either case means no syscall
|
||
* restarts for us, so let $18 and $19 burn.
|
||
*/
|
||
jsr $26, schedule
|
||
mov 0, $18
|
||
br ret_to_user
|
||
|
||
$work_notifysig:
|
||
mov $sp, $16
|
||
DO_SWITCH_STACK
|
||
jsr $26, do_work_pending
|
||
UNDO_SWITCH_STACK
|
||
br restore_all
|
||
|
||
/*
|
||
* PTRACE syscall handler
|
||
*/
|
||
|
||
.align 4
|
||
.type strace, @function
|
||
strace:
|
||
/* set up signal stack, call syscall_trace */
|
||
// NB: if anyone adds preemption, this block will need to be protected
|
||
ldl $1, TI_STATUS($8)
|
||
and $1, TS_SAVED_FP, $3
|
||
or $1, TS_SAVED_FP, $2
|
||
bne $3, 1f
|
||
stl $2, TI_STATUS($8)
|
||
bsr $26, __save_fpu
|
||
1:
|
||
DO_SWITCH_STACK
|
||
jsr $26, syscall_trace_enter /* returns the syscall number */
|
||
UNDO_SWITCH_STACK
|
||
|
||
/* get the arguments back.. */
|
||
ldq $16, SP_OFF+24($sp)
|
||
ldq $17, SP_OFF+32($sp)
|
||
ldq $18, SP_OFF+40($sp)
|
||
ldq $19, 72($sp)
|
||
ldq $20, 80($sp)
|
||
ldq $21, 88($sp)
|
||
|
||
/* get the system call pointer.. */
|
||
lda $1, NR_syscalls($31)
|
||
lda $2, sys_call_table
|
||
lda $27, sys_ni_syscall
|
||
cmpult $0, $1, $1
|
||
s8addq $0, $2, $2
|
||
beq $1, 1f
|
||
ldq $27, 0($2)
|
||
1: jsr $26, ($27), sys_gettimeofday
|
||
ret_from_straced:
|
||
ldgp $gp, 0($26)
|
||
|
||
/* check return.. */
|
||
blt $0, $strace_error /* the call failed */
|
||
$strace_success:
|
||
stq $31, 72($sp) /* a3=0 => no error */
|
||
stq $0, 0($sp) /* save return value */
|
||
|
||
DO_SWITCH_STACK
|
||
jsr $26, syscall_trace_leave
|
||
UNDO_SWITCH_STACK
|
||
br $31, ret_from_sys_call
|
||
|
||
.align 3
|
||
$strace_error:
|
||
ldq $18, 0($sp) /* old syscall nr (zero if success) */
|
||
beq $18, $strace_success
|
||
ldq $19, 72($sp) /* .. and this a3 */
|
||
|
||
subq $31, $0, $0 /* with error in v0 */
|
||
addq $31, 1, $1 /* set a3 for errno return */
|
||
stq $0, 0($sp)
|
||
stq $1, 72($sp) /* a3 for return */
|
||
|
||
DO_SWITCH_STACK
|
||
mov $18, $9 /* save old syscall number */
|
||
mov $19, $10 /* save old a3 */
|
||
jsr $26, syscall_trace_leave
|
||
mov $9, $18
|
||
mov $10, $19
|
||
UNDO_SWITCH_STACK
|
||
|
||
mov $31, $26 /* tell "ret_from_sys_call" we can restart */
|
||
br ret_from_sys_call
|
||
CFI_END_OSF_FRAME entSys
|
||
|
||
/*
|
||
* Save and restore the switch stack -- aka the balance of the user context.
|
||
*/
|
||
|
||
.align 4
|
||
.type do_switch_stack, @function
|
||
.cfi_startproc simple
|
||
.cfi_return_column 64
|
||
.cfi_def_cfa $sp, 0
|
||
.cfi_register 64, $1
|
||
do_switch_stack:
|
||
lda $sp, -SWITCH_STACK_SIZE($sp)
|
||
.cfi_adjust_cfa_offset SWITCH_STACK_SIZE
|
||
stq $9, 0($sp)
|
||
stq $10, 8($sp)
|
||
stq $11, 16($sp)
|
||
stq $12, 24($sp)
|
||
stq $13, 32($sp)
|
||
stq $14, 40($sp)
|
||
stq $15, 48($sp)
|
||
stq $26, 56($sp)
|
||
ret $31, ($1), 1
|
||
.cfi_endproc
|
||
.size do_switch_stack, .-do_switch_stack
|
||
|
||
.align 4
|
||
.type undo_switch_stack, @function
|
||
.cfi_startproc simple
|
||
.cfi_def_cfa $sp, 0
|
||
.cfi_register 64, $1
|
||
undo_switch_stack:
|
||
ldq $9, 0($sp)
|
||
ldq $10, 8($sp)
|
||
ldq $11, 16($sp)
|
||
ldq $12, 24($sp)
|
||
ldq $13, 32($sp)
|
||
ldq $14, 40($sp)
|
||
ldq $15, 48($sp)
|
||
ldq $26, 56($sp)
|
||
lda $sp, SWITCH_STACK_SIZE($sp)
|
||
ret $31, ($1), 1
|
||
.cfi_endproc
|
||
.size undo_switch_stack, .-undo_switch_stack
|
||
|
||
#define FR(n) n * 8 + TI_FP($8)
|
||
.align 4
|
||
.globl __save_fpu
|
||
.type __save_fpu, @function
|
||
__save_fpu:
|
||
#define V(n) stt $f##n, FR(n)
|
||
V( 0); V( 1); V( 2); V( 3)
|
||
V( 4); V( 5); V( 6); V( 7)
|
||
V( 8); V( 9); V(10); V(11)
|
||
V(12); V(13); V(14); V(15)
|
||
V(16); V(17); V(18); V(19)
|
||
V(20); V(21); V(22); V(23)
|
||
V(24); V(25); V(26); V(27)
|
||
mf_fpcr $f0 # get fpcr
|
||
V(28); V(29); V(30)
|
||
stt $f0, FR(31) # save fpcr in slot of $f31
|
||
ldt $f0, FR(0) # don't let "__save_fpu" change fp state.
|
||
ret
|
||
#undef V
|
||
.size __save_fpu, .-__save_fpu
|
||
|
||
.align 4
|
||
restore_fpu:
|
||
and $3, TS_RESTORE_FP, $3
|
||
bic $2, TS_SAVED_FP | TS_RESTORE_FP, $2
|
||
beq $3, 1f
|
||
#define V(n) ldt $f##n, FR(n)
|
||
ldt $f30, FR(31) # get saved fpcr
|
||
V( 0); V( 1); V( 2); V( 3)
|
||
mt_fpcr $f30 # install saved fpcr
|
||
V( 4); V( 5); V( 6); V( 7)
|
||
V( 8); V( 9); V(10); V(11)
|
||
V(12); V(13); V(14); V(15)
|
||
V(16); V(17); V(18); V(19)
|
||
V(20); V(21); V(22); V(23)
|
||
V(24); V(25); V(26); V(27)
|
||
V(28); V(29); V(30)
|
||
1: stl $2, TI_STATUS($8)
|
||
br restore_other
|
||
#undef V
|
||
|
||
|
||
/*
|
||
* The meat of the context switch code.
|
||
*/
|
||
.align 4
|
||
.globl alpha_switch_to
|
||
.type alpha_switch_to, @function
|
||
.cfi_startproc
|
||
alpha_switch_to:
|
||
DO_SWITCH_STACK
|
||
ldl $1, TI_STATUS($8)
|
||
and $1, TS_RESTORE_FP, $3
|
||
bne $3, 1f
|
||
or $1, TS_RESTORE_FP | TS_SAVED_FP, $2
|
||
and $1, TS_SAVED_FP, $3
|
||
stl $2, TI_STATUS($8)
|
||
bne $3, 1f
|
||
bsr $26, __save_fpu
|
||
1:
|
||
call_pal PAL_swpctx
|
||
lda $8, 0x3fff
|
||
UNDO_SWITCH_STACK
|
||
bic $sp, $8, $8
|
||
mov $17, $0
|
||
ret
|
||
.cfi_endproc
|
||
.size alpha_switch_to, .-alpha_switch_to
|
||
|
||
/*
|
||
* New processes begin life here.
|
||
*/
|
||
|
||
.globl ret_from_fork
|
||
.align 4
|
||
.ent ret_from_fork
|
||
ret_from_fork:
|
||
lda $26, ret_to_user
|
||
mov $17, $16
|
||
jmp $31, schedule_tail
|
||
.end ret_from_fork
|
||
|
||
/*
|
||
* ... and new kernel threads - here
|
||
*/
|
||
.align 4
|
||
.globl ret_from_kernel_thread
|
||
.ent ret_from_kernel_thread
|
||
ret_from_kernel_thread:
|
||
mov $17, $16
|
||
jsr $26, schedule_tail
|
||
mov $9, $27
|
||
mov $10, $16
|
||
jsr $26, ($9)
|
||
br $31, ret_to_user
|
||
.end ret_from_kernel_thread
|
||
|
||
|
||
/*
|
||
* Special system calls. Most of these are special in that they either
|
||
* have to play switch_stack games.
|
||
*/
|
||
|
||
.macro fork_like name
|
||
.align 4
|
||
.globl alpha_\name
|
||
.ent alpha_\name
|
||
alpha_\name:
|
||
.prologue 0
|
||
bsr $1, do_switch_stack
|
||
// NB: if anyone adds preemption, this block will need to be protected
|
||
ldl $1, TI_STATUS($8)
|
||
and $1, TS_SAVED_FP, $3
|
||
or $1, TS_SAVED_FP, $2
|
||
bne $3, 1f
|
||
stl $2, TI_STATUS($8)
|
||
bsr $26, __save_fpu
|
||
1:
|
||
jsr $26, sys_\name
|
||
ldq $26, 56($sp)
|
||
lda $sp, SWITCH_STACK_SIZE($sp)
|
||
ret
|
||
.end alpha_\name
|
||
.endm
|
||
|
||
fork_like fork
|
||
fork_like vfork
|
||
fork_like clone
|
||
fork_like clone3
|
||
|
||
.macro sigreturn_like name
|
||
.align 4
|
||
.globl sys_\name
|
||
.ent sys_\name
|
||
sys_\name:
|
||
.prologue 0
|
||
lda $9, ret_from_straced
|
||
cmpult $26, $9, $9
|
||
lda $sp, -SWITCH_STACK_SIZE($sp)
|
||
jsr $26, do_\name
|
||
bne $9, 1f
|
||
jsr $26, syscall_trace_leave
|
||
1: br $1, undo_switch_stack
|
||
br ret_from_sys_call
|
||
.end sys_\name
|
||
.endm
|
||
|
||
sigreturn_like sigreturn
|
||
sigreturn_like rt_sigreturn
|
||
|
||
.align 4
|
||
.globl alpha_syscall_zero
|
||
.ent alpha_syscall_zero
|
||
alpha_syscall_zero:
|
||
.prologue 0
|
||
/* Special because it needs to do something opposite to
|
||
force_successful_syscall_return(). We use the saved
|
||
syscall number for that, zero meaning "not an error".
|
||
That works nicely, but for real syscall 0 we need to
|
||
make sure that this logics doesn't get confused.
|
||
Store a non-zero there - -ENOSYS we need in register
|
||
for our return value will do just fine.
|
||
*/
|
||
lda $0, -ENOSYS
|
||
unop
|
||
stq $0, 0($sp)
|
||
ret
|
||
.end alpha_syscall_zero
|