forked from Minki/linux
677 lines
14 KiB
ArmAsm
677 lines
14 KiB
ArmAsm
/*
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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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/* Stack offsets. */
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#define SP_OFF 184
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#define SWITCH_STACK_SIZE 320
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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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#define SAVE_ALL \
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subq $sp, SP_OFF, $sp; \
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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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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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#define 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:; \
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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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/*
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* Non-syscall kernel entry points.
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*/
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.align 4
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.globl entInt
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.ent entInt
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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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.end entInt
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.align 4
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.globl entArith
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.ent entArith
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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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.end entArith
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.align 4
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.globl entMM
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.ent entMM
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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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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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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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/* finish up the syscall as normal. */
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br ret_from_sys_call
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.end entMM
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.align 4
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.globl entIF
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.ent entIF
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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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.end entIF
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.align 4
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.globl entUna
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.ent entUna
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entUna:
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lda $sp, -256($sp)
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stq $0, 0($sp)
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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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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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call_pal PAL_rti
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.end entUna
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.align 4
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.ent entUnaUser
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entUnaUser:
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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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SAVE_ALL /* setup normal kernel stack */
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lda $sp, -56($sp)
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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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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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br ret_from_sys_call
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.end entUnaUser
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.align 4
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.globl entDbg
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.ent entDbg
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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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.end 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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.globl ret_from_sys_call
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.ent entSys
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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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blbs $3, strace
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beq $4, 1f
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ldq $27, 0($5)
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1: jsr $26, ($27), alpha_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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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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ret_from_sys_call:
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cmovne $26, 0, $18 /* $18 = 0 => non-restartable */
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ldq $0, SP_OFF($sp)
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and $0, 8, $0
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beq $0, ret_to_kernel
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ret_to_user:
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/* Make sure need_resched and sigpending don't change between
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sampling and the rti. */
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lda $16, 7
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call_pal PAL_swpipl
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ldl $17, TI_FLAGS($8)
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and $17, _TIF_WORK_MASK, $2
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bne $2, work_pending
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restore_all:
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RESTORE_ALL
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call_pal PAL_rti
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ret_to_kernel:
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lda $16, 7
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call_pal PAL_swpipl
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br restore_all
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.align 3
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$syscall_error:
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/*
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* Some system calls (e.g., ptrace) can return arbitrary
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* values which might normally be mistaken as error numbers.
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* Those functions must zero $0 (v0) directly in the stack
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* frame to indicate that a negative return value wasn't an
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* error number..
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*/
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ldq $18, 0($sp) /* old syscall nr (zero if success) */
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beq $18, $ret_success
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ldq $19, 72($sp) /* .. and this a3 */
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subq $31, $0, $0 /* with error in v0 */
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addq $31, 1, $1 /* set a3 for errno return */
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stq $0, 0($sp)
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mov $31, $26 /* tell "ret_from_sys_call" we can restart */
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stq $1, 72($sp) /* a3 for return */
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br ret_from_sys_call
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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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br ret_from_sys_call
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.end entSys
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/*
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* Do all cleanup when returning from all interrupts and system calls.
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*
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* Arguments:
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* $8: current.
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* $17: TI_FLAGS.
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* $18: The old syscall number, or zero if this is not a return
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* from a syscall that errored and is possibly restartable.
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* $19: The old a3 value
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*/
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.align 4
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.ent work_pending
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work_pending:
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and $17, _TIF_NOTIFY_RESUME | _TIF_SIGPENDING, $2
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bne $2, $work_notifysig
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$work_resched:
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/*
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* We can get here only if we returned from syscall without SIGPENDING
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* or got through work_notifysig already. Either case means no syscall
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* restarts for us, so let $18 and $19 burn.
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*/
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jsr $26, schedule
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mov 0, $18
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br ret_to_user
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$work_notifysig:
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mov $sp, $16
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bsr $1, do_switch_stack
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jsr $26, do_work_pending
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bsr $1, undo_switch_stack
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br restore_all
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.end work_pending
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/*
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* PTRACE syscall handler
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*/
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.align 4
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.ent strace
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strace:
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/* set up signal stack, call syscall_trace */
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bsr $1, do_switch_stack
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jsr $26, syscall_trace_enter /* returns the syscall number */
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bsr $1, undo_switch_stack
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/* get the arguments back.. */
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ldq $16, SP_OFF+24($sp)
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ldq $17, SP_OFF+32($sp)
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ldq $18, SP_OFF+40($sp)
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ldq $19, 72($sp)
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ldq $20, 80($sp)
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ldq $21, 88($sp)
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/* get the system call pointer.. */
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lda $1, NR_SYSCALLS($31)
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lda $2, sys_call_table
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lda $27, alpha_ni_syscall
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cmpult $0, $1, $1
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s8addq $0, $2, $2
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beq $1, 1f
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ldq $27, 0($2)
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1: jsr $26, ($27), sys_gettimeofday
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ret_from_straced:
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ldgp $gp, 0($26)
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/* check return.. */
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blt $0, $strace_error /* the call failed */
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stq $31, 72($sp) /* a3=0 => no error */
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$strace_success:
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stq $0, 0($sp) /* save return value */
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bsr $1, do_switch_stack
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jsr $26, syscall_trace_leave
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bsr $1, undo_switch_stack
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br $31, ret_from_sys_call
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.align 3
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$strace_error:
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ldq $18, 0($sp) /* old syscall nr (zero if success) */
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beq $18, $strace_success
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ldq $19, 72($sp) /* .. and this a3 */
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subq $31, $0, $0 /* with error in v0 */
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addq $31, 1, $1 /* set a3 for errno return */
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stq $0, 0($sp)
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stq $1, 72($sp) /* a3 for return */
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bsr $1, do_switch_stack
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mov $18, $9 /* save old syscall number */
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mov $19, $10 /* save old a3 */
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jsr $26, syscall_trace_leave
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mov $9, $18
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mov $10, $19
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bsr $1, undo_switch_stack
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mov $31, $26 /* tell "ret_from_sys_call" we can restart */
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br ret_from_sys_call
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.end strace
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/*
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* Save and restore the switch stack -- aka the balance of the user context.
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*/
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.align 4
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.ent do_switch_stack
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do_switch_stack:
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lda $sp, -SWITCH_STACK_SIZE($sp)
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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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stq $26, 56($sp)
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stt $f0, 64($sp)
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stt $f1, 72($sp)
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stt $f2, 80($sp)
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stt $f3, 88($sp)
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stt $f4, 96($sp)
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stt $f5, 104($sp)
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stt $f6, 112($sp)
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stt $f7, 120($sp)
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stt $f8, 128($sp)
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stt $f9, 136($sp)
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stt $f10, 144($sp)
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stt $f11, 152($sp)
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stt $f12, 160($sp)
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stt $f13, 168($sp)
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stt $f14, 176($sp)
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stt $f15, 184($sp)
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stt $f16, 192($sp)
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stt $f17, 200($sp)
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stt $f18, 208($sp)
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stt $f19, 216($sp)
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stt $f20, 224($sp)
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stt $f21, 232($sp)
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stt $f22, 240($sp)
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stt $f23, 248($sp)
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stt $f24, 256($sp)
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stt $f25, 264($sp)
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stt $f26, 272($sp)
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stt $f27, 280($sp)
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mf_fpcr $f0 # get fpcr
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stt $f28, 288($sp)
|
||
stt $f29, 296($sp)
|
||
stt $f30, 304($sp)
|
||
stt $f0, 312($sp) # save fpcr in slot of $f31
|
||
ldt $f0, 64($sp) # dont let "do_switch_stack" change fp state.
|
||
ret $31, ($1), 1
|
||
.end do_switch_stack
|
||
|
||
.align 4
|
||
.ent undo_switch_stack
|
||
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)
|
||
ldt $f30, 312($sp) # get saved fpcr
|
||
ldt $f0, 64($sp)
|
||
ldt $f1, 72($sp)
|
||
ldt $f2, 80($sp)
|
||
ldt $f3, 88($sp)
|
||
mt_fpcr $f30 # install saved fpcr
|
||
ldt $f4, 96($sp)
|
||
ldt $f5, 104($sp)
|
||
ldt $f6, 112($sp)
|
||
ldt $f7, 120($sp)
|
||
ldt $f8, 128($sp)
|
||
ldt $f9, 136($sp)
|
||
ldt $f10, 144($sp)
|
||
ldt $f11, 152($sp)
|
||
ldt $f12, 160($sp)
|
||
ldt $f13, 168($sp)
|
||
ldt $f14, 176($sp)
|
||
ldt $f15, 184($sp)
|
||
ldt $f16, 192($sp)
|
||
ldt $f17, 200($sp)
|
||
ldt $f18, 208($sp)
|
||
ldt $f19, 216($sp)
|
||
ldt $f20, 224($sp)
|
||
ldt $f21, 232($sp)
|
||
ldt $f22, 240($sp)
|
||
ldt $f23, 248($sp)
|
||
ldt $f24, 256($sp)
|
||
ldt $f25, 264($sp)
|
||
ldt $f26, 272($sp)
|
||
ldt $f27, 280($sp)
|
||
ldt $f28, 288($sp)
|
||
ldt $f29, 296($sp)
|
||
ldt $f30, 304($sp)
|
||
lda $sp, SWITCH_STACK_SIZE($sp)
|
||
ret $31, ($1), 1
|
||
.end undo_switch_stack
|
||
|
||
/*
|
||
* The meat of the context switch code.
|
||
*/
|
||
|
||
.align 4
|
||
.globl alpha_switch_to
|
||
.ent alpha_switch_to
|
||
alpha_switch_to:
|
||
.prologue 0
|
||
bsr $1, do_switch_stack
|
||
call_pal PAL_swpctx
|
||
lda $8, 0x3fff
|
||
bsr $1, undo_switch_stack
|
||
bic $sp, $8, $8
|
||
mov $17, $0
|
||
ret
|
||
.end alpha_switch_to
|
||
|
||
/*
|
||
* New processes begin life here.
|
||
*/
|
||
|
||
.globl ret_from_fork
|
||
.align 4
|
||
.ent ret_from_fork
|
||
ret_from_fork:
|
||
lda $26, ret_from_sys_call
|
||
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)
|
||
mov $31, $19 /* to disable syscall restarts */
|
||
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 or in some way use the pt_regs struct.
|
||
*/
|
||
|
||
.macro fork_like name
|
||
.align 4
|
||
.globl alpha_\name
|
||
.ent alpha_\name
|
||
alpha_\name:
|
||
.prologue 0
|
||
bsr $1, do_switch_stack
|
||
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
|
||
|
||
.align 4
|
||
.globl sys_sigreturn
|
||
.ent sys_sigreturn
|
||
sys_sigreturn:
|
||
.prologue 0
|
||
lda $9, ret_from_straced
|
||
cmpult $26, $9, $9
|
||
lda $sp, -SWITCH_STACK_SIZE($sp)
|
||
jsr $26, do_sigreturn
|
||
bne $9, 1f
|
||
jsr $26, syscall_trace_leave
|
||
1: br $1, undo_switch_stack
|
||
br ret_from_sys_call
|
||
.end sys_sigreturn
|
||
|
||
.align 4
|
||
.globl sys_rt_sigreturn
|
||
.ent sys_rt_sigreturn
|
||
sys_rt_sigreturn:
|
||
.prologue 0
|
||
lda $9, ret_from_straced
|
||
cmpult $26, $9, $9
|
||
lda $sp, -SWITCH_STACK_SIZE($sp)
|
||
jsr $26, do_rt_sigreturn
|
||
bne $9, 1f
|
||
jsr $26, syscall_trace_leave
|
||
1: br $1, undo_switch_stack
|
||
br ret_from_sys_call
|
||
.end sys_rt_sigreturn
|
||
|
||
.align 4
|
||
.globl alpha_ni_syscall
|
||
.ent alpha_ni_syscall
|
||
alpha_ni_syscall:
|
||
.prologue 0
|
||
/* Special because it also implements overflow handling via
|
||
syscall number 0. And if you recall, zero is a special
|
||
trigger for "not an error". Store large non-zero there. */
|
||
lda $0, -ENOSYS
|
||
unop
|
||
stq $0, 0($sp)
|
||
ret
|
||
.end alpha_ni_syscall
|