2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 1994 - 2000, 2001, 2003 Ralf Baechle
7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
8 * Copyright (C) 2001 MIPS Technologies, Inc.
12 #include <asm/asmmacro.h>
13 #include <asm/regdef.h>
14 #include <asm/mipsregs.h>
15 #include <asm/stackframe.h>
16 #include <asm/isadep.h>
17 #include <asm/thread_info.h>
19 #ifdef CONFIG_MIPS_MT_SMTC
20 #include <asm/mipsmtregs.h>
23 #ifndef CONFIG_PREEMPT
24 #define resume_kernel restore_all
26 #define __ret_from_irq ret_from_exception
31 #ifndef CONFIG_PREEMPT
32 FEXPORT(ret_from_exception)
33 local_irq_disable # preempt stop
37 LONG_S s0, TI_REGS($28)
38 FEXPORT(__ret_from_irq)
40 * We can be coming here from a syscall done in the kernel space,
41 * e.g. a failed kernel_execve().
43 resume_userspace_check:
44 LONG_L t0, PT_STATUS(sp) # returning to kernel mode?
46 beqz t0, resume_kernel
49 local_irq_disable # make sure we dont miss an
50 # interrupt setting need_resched
51 # between sampling and return
52 LONG_L a2, TI_FLAGS($28) # current->work
53 andi t0, a2, _TIF_WORK_MASK # (ignoring syscall_trace)
60 lw t0, TI_PRE_COUNT($28)
63 LONG_L t0, TI_FLAGS($28)
64 andi t1, t0, _TIF_NEED_RESCHED
66 LONG_L t0, PT_STATUS(sp) # Interrupts off?
69 jal preempt_schedule_irq
73 FEXPORT(ret_from_fork)
74 jal schedule_tail # a0 = struct task_struct *prev
77 local_irq_disable # make sure need_resched and
78 # signals dont change between
80 LONG_L a2, TI_FLAGS($28) # current->work
81 li t0, _TIF_ALLWORK_MASK
83 bnez t0, syscall_exit_work
85 restore_all: # restore full frame
86 #ifdef CONFIG_MIPS_MT_SMTC
87 #ifdef CONFIG_MIPS_MT_SMTC_IM_BACKSTOP
88 /* Re-arm any temporarily masked interrupts not explicitly "acked" */
90 ori v1, v0, TCSTATUS_IXMT
92 andi v0, TCSTATUS_IXMT
94 mfc0 t0, CP0_TCCONTEXT
102 andi t1, t1, VPECONTROL_TE
106 mfc0 v1, CP0_TCSTATUS
107 /* We set IXMT above, XOR should clear it here */
108 xori v1, v1, TCSTATUS_IXMT
110 mtc0 v1, CP0_TCSTATUS
113 mtc0 t0, CP0_TCCONTEXT
114 #endif /* CONFIG_MIPS_MT_SMTC_IM_BACKSTOP */
115 /* Detect and execute deferred IPI "interrupts" */
116 LONG_L s0, TI_REGS($28)
117 LONG_S sp, TI_REGS($28)
118 jal deferred_smtc_ipi
119 LONG_S s0, TI_REGS($28)
120 #endif /* CONFIG_MIPS_MT_SMTC */
125 restore_partial: # restore partial frame
126 #ifdef CONFIG_TRACE_IRQFLAGS
130 LONG_L v0, PT_STATUS(sp)
131 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
137 jal trace_hardirqs_on
139 1: jal trace_hardirqs_off
150 andi t0, a2, _TIF_NEED_RESCHED # a2 is preloaded with TI_FLAGS
151 beqz t0, work_notifysig
155 local_irq_disable # make sure need_resched and
156 # signals dont change between
157 # sampling and return
158 LONG_L a2, TI_FLAGS($28)
159 andi t0, a2, _TIF_WORK_MASK # is there any work to be done
160 # other than syscall tracing?
162 andi t0, a2, _TIF_NEED_RESCHED
163 bnez t0, work_resched
165 work_notifysig: # deal with pending signals and
166 # notify-resume requests
169 jal do_notify_resume # a2 already loaded
170 j resume_userspace_check
172 FEXPORT(syscall_exit_partial)
173 local_irq_disable # make sure need_resched doesn't
174 # change between and return
175 LONG_L a2, TI_FLAGS($28) # current->work
176 li t0, _TIF_ALLWORK_MASK
178 beqz t0, restore_partial
181 LONG_L t0, PT_STATUS(sp) # returning to kernel mode?
183 beqz t0, resume_kernel
184 li t0, _TIF_WORK_SYSCALL_EXIT
185 and t0, a2 # a2 is preloaded with TI_FLAGS
186 beqz t0, work_pending # trace bit set?
187 local_irq_enable # could let syscall_trace_leave()
188 # call schedule() instead
190 jal syscall_trace_leave
193 #if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_MIPS_MT)
196 * MIPS32R2 Instruction Hazard Barrier - must be called
198 * For C code use the inline version named instruction_hazard().
206 #endif /* CONFIG_CPU_MIPSR2 or CONFIG_MIPS_MT */