diff options
Diffstat (limited to 'arch/alpha/kernel/entry.S')
| -rw-r--r-- | arch/alpha/kernel/entry.S | 155 |
1 files changed, 45 insertions, 110 deletions
diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S index ec0da0567ab..a7607832dd4 100644 --- a/arch/alpha/kernel/entry.S +++ b/arch/alpha/kernel/entry.S @@ -311,7 +311,7 @@ entSys: .align 4 ret_from_sys_call: - cmovne $26, 0, $19 /* $19 = 0 => non-restartable */ + cmovne $26, 0, $18 /* $18 = 0 => non-restartable */ ldq $0, SP_OFF($sp) and $0, 8, $0 beq $0, ret_to_kernel @@ -320,8 +320,8 @@ ret_to_user: sampling and the rti. */ lda $16, 7 call_pal PAL_swpipl - ldl $5, TI_FLAGS($8) - and $5, _TIF_WORK_MASK, $2 + ldl $17, TI_FLAGS($8) + and $17, _TIF_WORK_MASK, $2 bne $2, work_pending restore_all: RESTORE_ALL @@ -341,10 +341,10 @@ $syscall_error: * frame to indicate that a negative return value wasn't an * error number.. */ - ldq $19, 0($sp) /* old syscall nr (zero if success) */ - beq $19, $ret_success + ldq $18, 0($sp) /* old syscall nr (zero if success) */ + beq $18, $ret_success - ldq $20, 72($sp) /* .. and this a3 */ + 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) @@ -362,51 +362,35 @@ $ret_success: * Do all cleanup when returning from all interrupts and system calls. * * Arguments: - * $5: TI_FLAGS. * $8: current. - * $19: The old syscall number, or zero if this is not a return + * $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. - * $20: The old a3 value + * $19: The old a3 value */ .align 4 .ent work_pending work_pending: - and $5, _TIF_NEED_RESCHED, $2 - beq $2, $work_notifysig + and $17, _TIF_NOTIFY_RESUME | _TIF_SIGPENDING, $2 + bne $2, $work_notifysig $work_resched: - subq $sp, 16, $sp - stq $19, 0($sp) /* save syscall nr */ - stq $20, 8($sp) /* and error indication (a3) */ + /* + * 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 - ldq $19, 0($sp) - ldq $20, 8($sp) - addq $sp, 16, $sp - /* Make sure need_resched and sigpending don't change between - sampling and the rti. */ - lda $16, 7 - call_pal PAL_swpipl - ldl $5, TI_FLAGS($8) - and $5, _TIF_WORK_MASK, $2 - beq $2, restore_all - and $5, _TIF_NEED_RESCHED, $2 - bne $2, $work_resched + mov 0, $18 + br ret_to_user $work_notifysig: mov $sp, $16 bsr $1, do_switch_stack - mov $sp, $17 - mov $5, $18 - mov $19, $9 /* save old syscall number */ - mov $20, $10 /* save old a3 */ - and $5, _TIF_SIGPENDING, $2 - cmovne $2, 0, $9 /* we don't want double syscall restarts */ - jsr $26, do_notify_resume - mov $9, $19 - mov $10, $20 + jsr $26, do_work_pending bsr $1, undo_switch_stack - br ret_to_user + br restore_all .end work_pending /* @@ -418,11 +402,10 @@ $work_notifysig: strace: /* set up signal stack, call syscall_trace */ bsr $1, do_switch_stack - jsr $26, syscall_trace + jsr $26, syscall_trace_enter /* returns the syscall number */ bsr $1, undo_switch_stack - /* get the system call number and the arguments back.. */ - ldq $0, 0($sp) + /* get the arguments back.. */ ldq $16, SP_OFF+24($sp) ldq $17, SP_OFF+32($sp) ldq $18, SP_OFF+40($sp) @@ -449,15 +432,15 @@ $strace_success: stq $0, 0($sp) /* save return value */ bsr $1, do_switch_stack - jsr $26, syscall_trace + jsr $26, syscall_trace_leave bsr $1, undo_switch_stack br $31, ret_from_sys_call .align 3 $strace_error: - ldq $19, 0($sp) /* old syscall nr (zero if success) */ - beq $19, $strace_success - ldq $20, 72($sp) /* .. and this a3 */ + 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 */ @@ -465,11 +448,11 @@ $strace_error: stq $1, 72($sp) /* a3 for return */ bsr $1, do_switch_stack - mov $19, $9 /* save old syscall number */ - mov $20, $10 /* save old a3 */ - jsr $26, syscall_trace - mov $9, $19 - mov $10, $20 + mov $18, $9 /* save old syscall number */ + mov $19, $10 /* save old a3 */ + jsr $26, syscall_trace_leave + mov $9, $18 + mov $10, $19 bsr $1, undo_switch_stack mov $31, $26 /* tell "ret_from_sys_call" we can restart */ @@ -609,59 +592,20 @@ ret_from_fork: .end ret_from_fork /* - * kernel_thread(fn, arg, clone_flags) + * ... and new kernel threads - here */ .align 4 - .globl kernel_thread - .ent kernel_thread -kernel_thread: - /* We can be called from a module. */ - ldgp $gp, 0($27) - .prologue 1 - subq $sp, SP_OFF+6*8, $sp - br $1, 2f /* load start address */ - - /* We've now "returned" from a fake system call. */ - unop - blt $0, 1f /* error? */ - ldi $1, 0x3fff - beq $20, 1f /* parent or child? */ - - bic $sp, $1, $8 /* in child. */ - jsr $26, ($27) - ldgp $gp, 0($26) - mov $0, $16 - mov $31, $26 - jmp $31, sys_exit - -1: ret /* in parent. */ - - .align 4 -2: /* Fake a system call stack frame, as we can't do system calls - from kernel space. Note that we store FN and ARG as they - need to be set up in the child for the call. Also store $8 - and $26 for use in the parent. */ - stq $31, SP_OFF($sp) /* ps */ - stq $1, SP_OFF+8($sp) /* pc */ - stq $gp, SP_OFF+16($sp) /* gp */ - stq $16, 136($sp) /* $27; FN for child */ - stq $17, SP_OFF+24($sp) /* $16; ARG for child */ - stq $8, 64($sp) /* $8 */ - stq $26, 128($sp) /* $26 */ - /* Avoid the HAE being gratuitously wrong, to avoid restoring it. */ - ldq $2, alpha_mv+HAE_CACHE - stq $2, 152($sp) /* HAE */ - - /* Shuffle FLAGS to the front; add CLONE_VM. */ - ldi $1, CLONE_VM|CLONE_UNTRACED - or $18, $1, $16 - bsr $26, sys_clone - - /* We don't actually care for a3 success widgetry in the kernel. - Not for positive errno values. */ - stq $0, 0($sp) /* $0 */ - br ret_to_kernel -.end kernel_thread + .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 /* @@ -722,7 +666,7 @@ sys_sigreturn: lda $sp, -SWITCH_STACK_SIZE($sp) jsr $26, do_sigreturn bne $9, 1f - jsr $26, syscall_trace + jsr $26, syscall_trace_leave 1: br $1, undo_switch_stack br ret_from_sys_call .end sys_sigreturn @@ -739,21 +683,12 @@ sys_rt_sigreturn: lda $sp, -SWITCH_STACK_SIZE($sp) jsr $26, do_rt_sigreturn bne $9, 1f - jsr $26, syscall_trace + jsr $26, syscall_trace_leave 1: br $1, undo_switch_stack br ret_from_sys_call .end sys_rt_sigreturn .align 4 - .globl sys_execve - .ent sys_execve -sys_execve: - .prologue 0 - mov $sp, $19 - jmp $31, do_sys_execve -.end sys_execve - - .align 4 .globl alpha_ni_syscall .ent alpha_ni_syscall alpha_ni_syscall: |