1 /* $Id: rtrap.S,v 1.61 2002/02/09 19:49:31 davem Exp $
2 * rtrap.S: Preparing for return from trap on Sparc V9.
4 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
5 * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
8 #include <linux/config.h>
11 #include <asm/pstate.h>
12 #include <asm/ptrace.h>
13 #include <asm/spitfire.h>
15 #include <asm/visasm.h>
16 #include <asm/processor.h>
18 #define RTRAP_PSTATE (PSTATE_RMO|PSTATE_PEF|PSTATE_PRIV|PSTATE_IE)
19 #define RTRAP_PSTATE_IRQOFF (PSTATE_RMO|PSTATE_PEF|PSTATE_PRIV)
20 #define RTRAP_PSTATE_AG_IRQOFF (PSTATE_RMO|PSTATE_PEF|PSTATE_PRIV|PSTATE_AG)
22 /* Register %l6 keeps track of whether we are returning
23 * from a system call or not. It is cleared if we call
24 * do_notify_resume, and it must not be otherwise modified
25 * until we fully commit to returning to userspace.
33 ba,a,pt %xcc, __handle_softirq_continue
37 wrpr %g0, RTRAP_PSTATE, %pstate
38 ba,pt %xcc, __handle_preemption_continue
39 wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate
41 __handle_user_windows:
42 call fault_in_user_windows
43 wrpr %g0, RTRAP_PSTATE, %pstate
44 wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate
45 /* Redo sched+sig checks */
46 ldx [%g6 + TI_FLAGS], %l0
47 andcc %l0, _TIF_NEED_RESCHED, %g0
52 wrpr %g0, RTRAP_PSTATE, %pstate
53 wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate
54 ldx [%g6 + TI_FLAGS], %l0
56 1: andcc %l0, (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING), %g0
57 be,pt %xcc, __handle_user_windows_continue
62 add %sp, PTREGS_OFF, %o1
66 wrpr %g0, RTRAP_PSTATE, %pstate
67 wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate
69 /* Signal delivery can modify pt_regs tstate, so we must
72 ldx [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
73 sethi %hi(0xf << 20), %l4
75 ba,pt %xcc, __handle_user_windows_continue
80 wrpr %g0, RTRAP_PSTATE, %pstate
81 wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate
82 ldub [%g6 + TI_WSAVED], %o2
85 /* Redo userwin+sched+sig checks */
86 call fault_in_user_windows
88 wrpr %g0, RTRAP_PSTATE, %pstate
89 wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate
90 ldx [%g6 + TI_FLAGS], %l0
91 andcc %l0, _TIF_NEED_RESCHED, %g0
96 wrpr %g0, RTRAP_PSTATE, %pstate
97 wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate
98 ldx [%g6 + TI_FLAGS], %l0
99 1: andcc %l0, (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING), %g0
101 be,pt %xcc, __handle_perfctrs_continue
102 sethi %hi(TSTATE_PEF), %o0
106 add %sp, PTREGS_OFF, %o1
108 call do_notify_resume
110 wrpr %g0, RTRAP_PSTATE, %pstate
111 wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate
113 /* Signal delivery can modify pt_regs tstate, so we must
116 ldx [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
117 sethi %hi(0xf << 20), %l4
120 ba,pt %xcc, __handle_perfctrs_continue
122 sethi %hi(TSTATE_PEF), %o0
125 andcc %l5, FPRS_FEF, %g0
126 sethi %hi(TSTATE_PEF), %o0
127 be,a,pn %icc, __handle_userfpu_continue
129 ba,a,pt %xcc, __handle_userfpu_continue
135 add %sp, PTREGS_OFF, %o1
137 call do_notify_resume
138 wrpr %g0, RTRAP_PSTATE, %pstate
139 wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate
142 /* Signal delivery can modify pt_regs tstate, so we must
145 ldx [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
146 sethi %hi(0xf << 20), %l4
148 ba,pt %xcc, __handle_signal_continue
152 .globl rtrap_irq, rtrap_clr_l6, rtrap, irqsz_patchme, rtrap_xcall
154 rtrap_clr_l6: clr %l6
155 rtrap: ldub [%g6 + TI_CPU], %l0
156 sethi %hi(irq_stat), %l2 ! &softirq_active
157 or %l2, %lo(irq_stat), %l2 ! &softirq_active
158 irqsz_patchme: sllx %l0, 0, %l0
159 lduw [%l2 + %l0], %l1 ! softirq_pending
162 /* mm/ultra.S:xcall_report_regs KNOWS about this load. */
163 bne,pn %icc, __handle_softirq
164 ldx [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
165 __handle_softirq_continue:
167 sethi %hi(0xf << 20), %l4
168 andcc %l1, TSTATE_PRIV, %l3
170 bne,pn %icc, to_kernel
173 /* We must hold IRQs off and atomically test schedule+signal
174 * state, then hold them off all the way back to userspace.
175 * If we are returning to kernel, none of this matters.
177 * If we do not do this, there is a window where we would do
178 * the tests, later the signal/resched event arrives but we do
179 * not process it since we are still in kernel mode. It would
180 * take until the next local IRQ before the signal/resched
181 * event would be handled.
183 * This also means that if we have to deal with performance
184 * counters or user windows, we have to redo all of these
185 * sched+signal checks with IRQs disabled.
187 to_user: wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate
189 __handle_preemption_continue:
190 ldx [%g6 + TI_FLAGS], %l0
191 sethi %hi(_TIF_USER_WORK_MASK), %o0
192 or %o0, %lo(_TIF_USER_WORK_MASK), %o0
194 sethi %hi(TSTATE_PEF), %o0
195 be,pt %xcc, user_nowork
197 andcc %l0, _TIF_NEED_RESCHED, %g0
198 bne,pn %xcc, __handle_preemption
199 andcc %l0, (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING), %g0
200 bne,pn %xcc, __handle_signal
201 __handle_signal_continue:
202 ldub [%g6 + TI_WSAVED], %o2
203 brnz,pn %o2, __handle_user_windows
205 __handle_user_windows_continue:
206 ldx [%g6 + TI_FLAGS], %l5
207 andcc %l5, _TIF_PERFCTR, %g0
208 sethi %hi(TSTATE_PEF), %o0
209 bne,pn %xcc, __handle_perfctrs
210 __handle_perfctrs_continue:
213 /* This fpdepth clear is necessary for non-syscall rtraps only */
215 bne,pn %xcc, __handle_userfpu
216 stb %g0, [%g6 + TI_FPDEPTH]
217 __handle_userfpu_continue:
219 rt_continue: ldx [%sp + PTREGS_OFF + PT_V9_G1], %g1
220 ldx [%sp + PTREGS_OFF + PT_V9_G2], %g2
222 ldx [%sp + PTREGS_OFF + PT_V9_G3], %g3
223 ldx [%sp + PTREGS_OFF + PT_V9_G4], %g4
224 ldx [%sp + PTREGS_OFF + PT_V9_G5], %g5
225 ldx [%sp + PTREGS_OFF + PT_V9_G6], %g6
226 ldx [%sp + PTREGS_OFF + PT_V9_G7], %g7
227 wrpr %g0, RTRAP_PSTATE_AG_IRQOFF, %pstate
228 ldx [%sp + PTREGS_OFF + PT_V9_I0], %i0
229 ldx [%sp + PTREGS_OFF + PT_V9_I1], %i1
231 ldx [%sp + PTREGS_OFF + PT_V9_I2], %i2
232 ldx [%sp + PTREGS_OFF + PT_V9_I3], %i3
233 ldx [%sp + PTREGS_OFF + PT_V9_I4], %i4
234 ldx [%sp + PTREGS_OFF + PT_V9_I5], %i5
235 ldx [%sp + PTREGS_OFF + PT_V9_I6], %i6
236 ldx [%sp + PTREGS_OFF + PT_V9_I7], %i7
237 ldx [%sp + PTREGS_OFF + PT_V9_TPC], %l2
238 ldx [%sp + PTREGS_OFF + PT_V9_TNPC], %o2
240 ld [%sp + PTREGS_OFF + PT_V9_Y], %o3
245 wrpr %l1, %g0, %tstate
249 brnz,pn %l3, kern_rtt
250 mov PRIMARY_CONTEXT, %l7
251 ldxa [%l7 + %l7] ASI_DMMU, %l0
252 stxa %l0, [%l7] ASI_DMMU
258 wrpr %l2, %g0, %canrestore
259 wrpr %l1, %g0, %wstate
260 wrpr %g0, %g0, %otherwin
262 rdpr %canrestore, %g1
263 wrpr %g1, 0x0, %cleanwin
270 #ifdef CONFIG_PREEMPT
271 ldsw [%g6 + TI_PRE_COUNT], %l5
272 brnz %l5, kern_fpucheck
273 ldx [%g6 + TI_FLAGS], %l5
274 andcc %l5, _TIF_NEED_RESCHED, %g0
275 be,pt %xcc, kern_fpucheck
278 bne,pn %xcc, kern_fpucheck
279 sethi %hi(PREEMPT_ACTIVE), %l6
280 stw %l6, [%g6 + TI_PRE_COUNT]
284 stw %g0, [%g6 + TI_PRE_COUNT]
286 kern_fpucheck: ldub [%g6 + TI_FPDEPTH], %l5
287 brz,pt %l5, rt_continue
289 add %g6, TI_FPSAVED, %l6
290 ldub [%l6 + %o0], %l2
294 andcc %l2, (FPRS_FEF|FPRS_DU), %g0
296 and %l2, FPRS_DL, %l6
297 andcc %l2, FPRS_FEF, %g0
302 wr %g5, FPRS_FEF, %fprs
304 add %g6, TI_XFSR, %o1
305 membar #StoreLoad | #LoadLoad
307 add %g6, TI_FPREGS, %o3
309 add %g6, TI_FPREGS+0x40, %o4
311 ldda [%o3 + %o2] ASI_BLK_P, %f0
312 ldda [%o4 + %o2] ASI_BLK_P, %f16
313 1: andcc %l2, FPRS_DU, %g0
317 ldda [%o3 + %o2] ASI_BLK_P, %f32
318 ldda [%o4 + %o2] ASI_BLK_P, %f48
321 ldx [%o1 + %o5], %fsr
322 2: stb %l5, [%g6 + TI_FPDEPTH]
323 ba,pt %xcc, rt_continue
325 5: wr %g0, FPRS_FEF, %fprs
326 membar #StoreLoad | #LoadLoad
329 add %g6, TI_FPREGS+0x80, %o3
330 add %g6, TI_FPREGS+0xc0, %o4
331 ldda [%o3 + %o2] ASI_BLK_P, %f32
332 ldda [%o4 + %o2] ASI_BLK_P, %f48
334 wr %g0, FPRS_DU, %fprs
335 ba,pt %xcc, rt_continue
336 stb %l5, [%g6 + TI_FPDEPTH]