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, 95, 96, 99, 2001 Ralf Baechle
7 * Copyright (C) 1994, 1995, 1996 Paul M. Antoine.
8 * Copyright (C) 1999 Silicon Graphics, Inc.
9 * Copyright (C) 2007 Maciej W. Rozycki
11 #ifndef _ASM_STACKFRAME_H
12 #define _ASM_STACKFRAME_H
14 #include <linux/threads.h>
17 #include <asm/asmmacro.h>
18 #include <asm/mipsregs.h>
19 #include <asm/asm-offsets.h>
22 * For SMTC kernel, global IE should be left set, and interrupts
23 * controlled exclusively via IXMT.
25 #ifdef CONFIG_MIPS_MT_SMTC
27 #elif defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
33 #ifdef CONFIG_MIPS_MT_SMTC
34 #include <asm/mipsmtregs.h>
35 #endif /* CONFIG_MIPS_MT_SMTC */
45 #ifdef CONFIG_CPU_HAS_SMARTMIPS
62 LONG_S $
10, PT_R10(sp
)
63 LONG_S $
11, PT_R11(sp
)
64 LONG_S $
12, PT_R12(sp
)
65 LONG_S $
13, PT_R13(sp
)
66 LONG_S $
14, PT_R14(sp
)
67 LONG_S $
15, PT_R15(sp
)
68 LONG_S $
24, PT_R24(sp
)
72 LONG_S $
16, PT_R16(sp
)
73 LONG_S $
17, PT_R17(sp
)
74 LONG_S $
18, PT_R18(sp
)
75 LONG_S $
19, PT_R19(sp
)
76 LONG_S $
20, PT_R20(sp
)
77 LONG_S $
21, PT_R21(sp
)
78 LONG_S $
22, PT_R22(sp
)
79 LONG_S $
23, PT_R23(sp
)
80 LONG_S $
30, PT_R30(sp
)
84 #ifdef CONFIG_MIPS_MT_SMTC
85 #define PTEBASE_SHIFT 19 /* TCBIND */
87 #define PTEBASE_SHIFT 23 /* CONTEXT */
89 .macro get_saved_sp
/* SMP variation */
90 #ifdef CONFIG_MIPS_MT_SMTC
95 #if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
98 lui k1
, %highest(kernelsp
)
99 daddiu k1
, %higher(kernelsp
)
101 daddiu k1
, %hi(kernelsp
)
104 LONG_SRL k0
, PTEBASE_SHIFT
106 LONG_L k1
, %lo(kernelsp
)(k1
)
109 .macro set_saved_sp stackp temp temp2
110 #ifdef CONFIG_MIPS_MT_SMTC
111 mfc0
\temp
, CP0_TCBIND
113 MFC0
\temp
, CP0_CONTEXT
115 LONG_SRL
\temp
, PTEBASE_SHIFT
116 LONG_S \stackp
, kernelsp(\temp
)
119 .macro get_saved_sp
/* Uniprocessor variation */
120 #if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
121 lui k1
, %hi(kernelsp
)
123 lui k1
, %highest(kernelsp
)
124 daddiu k1
, %higher(kernelsp
)
126 daddiu k1
, %hi(kernelsp
)
129 LONG_L k1
, %lo(kernelsp
)(k1
)
132 .macro set_saved_sp stackp temp temp2
133 LONG_S \stackp
, kernelsp
142 sll k0
, 3 /* extract cu0 bit */
147 /* Called from user mode, new stack. */
149 #ifndef CONFIG_CPU_DADDI_WORKAROUNDS
151 PTR_SUBU sp
, k1
, PT_SIZE
154 8: PTR_SUBU k1
, PT_SIZE
159 LONG_S k0
, PT_R29(sp
)
162 * You might think that you don't need to save $0,
163 * but the FPU emulator and gdb remote debug stub
164 * need it to operate correctly
169 LONG_S v1
, PT_STATUS(sp
)
170 #ifdef CONFIG_MIPS_MT_SMTC
172 * Ideally, these instructions would be shuffled in
173 * to cover the pipeline delay.
176 mfc0 v1
, CP0_TCSTATUS
178 LONG_S v1
, PT_TCSTATUS(sp
)
179 #endif /* CONFIG_MIPS_MT_SMTC */
183 LONG_S v1
, PT_CAUSE(sp
)
191 LONG_S v1
, PT_EPC(sp
)
192 LONG_S $
25, PT_R25(sp
)
193 LONG_S $
28, PT_R28(sp
)
194 LONG_S $
31, PT_R31(sp
)
195 ori $
28, sp
, _THREAD_MASK
196 xori $
28, _THREAD_MASK
197 #ifdef CONFIG_CPU_CAVIUM_OCTEON
199 pref
0, 0($
28) /* Prefetch the current pointer */
200 pref
0, PT_R31(sp
) /* Prefetch the $31(ra) */
201 /* The Octeon multiplier state is affected by general multiply
202 instructions. It must be saved before and kernel code might
205 LONG_L v1
, 0($
28) /* Load the current pointer */
206 /* Restore $31(ra) that was changed by the jal */
207 LONG_L ra
, PT_R31(sp
)
208 pref
0, 0(v1
) /* Prefetch the current thread */
228 #ifdef CONFIG_CPU_HAS_SMARTMIPS
229 LONG_L $
24, PT_ACX(sp
)
231 LONG_L $
24, PT_HI(sp
)
233 LONG_L $
24, PT_LO(sp
)
236 LONG_L $
24, PT_LO(sp
)
238 LONG_L $
24, PT_HI(sp
)
245 LONG_L $
10, PT_R10(sp
)
246 LONG_L $
11, PT_R11(sp
)
247 LONG_L $
12, PT_R12(sp
)
248 LONG_L $
13, PT_R13(sp
)
249 LONG_L $
14, PT_R14(sp
)
250 LONG_L $
15, PT_R15(sp
)
251 LONG_L $
24, PT_R24(sp
)
254 .macro RESTORE_STATIC
255 LONG_L $
16, PT_R16(sp
)
256 LONG_L $
17, PT_R17(sp
)
257 LONG_L $
18, PT_R18(sp
)
258 LONG_L $
19, PT_R19(sp
)
259 LONG_L $
20, PT_R20(sp
)
260 LONG_L $
21, PT_R21(sp
)
261 LONG_L $
22, PT_R22(sp
)
262 LONG_L $
23, PT_R23(sp
)
263 LONG_L $
30, PT_R30(sp
)
266 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
278 LONG_L v0
, PT_STATUS(sp
)
283 LONG_L $
31, PT_R31(sp
)
284 LONG_L $
28, PT_R28(sp
)
285 LONG_L $
25, PT_R25(sp
)
295 .macro RESTORE_SP_AND_RET
298 LONG_L k0
, PT_EPC(sp
)
299 LONG_L sp
, PT_R29(sp
)
310 #ifdef CONFIG_MIPS_MT_SMTC
313 * We need to make sure the read-modify-write
314 * of Status below isn't perturbed by an interrupt
315 * or cross-TC access, so we need to do at least a DMT,
316 * protected by an interrupt-inhibit. But setting IXMT
317 * also creates a few-cycle window where an IPI could
318 * be queued and not be detected before potentially
319 * returning to a WAIT or user-mode loop. It must be
322 * We're in the middle of a context switch, and
323 * we can't dispatch it directly without trashing
324 * some registers, so we'll try to detect this unlikely
325 * case and program a software interrupt in the VPE,
326 * as would be done for a cross-VPE IPI. To accomodate
327 * the handling of that case, we're doing a DVPE instead
328 * of just a DMT here to protect against other threads.
329 * This is a lot of cruft to cover a tiny window.
330 * If you can find a better design, implement it!
333 mfc0 v0
, CP0_TCSTATUS
334 ori v0
, TCSTATUS_IXMT
335 mtc0 v0
, CP0_TCSTATUS
339 #endif /* CONFIG_MIPS_MT_SMTC */
340 #ifdef CONFIG_CPU_CAVIUM_OCTEON
341 /* Restore the Octeon multiplier state */
342 jal octeon_mult_restore
350 LONG_L v0
, PT_STATUS(sp
)
355 #ifdef CONFIG_MIPS_MT_SMTC
357 * Only after EXL/ERL have been restored to status can we
358 * restore TCStatus.IXMT.
360 LONG_L v1
, PT_TCSTATUS(sp
)
362 mfc0 a0
, CP0_TCSTATUS
363 andi v1
, TCSTATUS_IXMT
367 * We'd like to detect any IPIs queued in the tiny window
368 * above and request an software interrupt to service them
371 * Computing the offset into the IPIQ array of the executing
372 * TC's IPI queue in-line would be tedious. We use part of
373 * the TCContext register to hold 16 bits of offset that we
374 * can add in-line to find the queue head.
376 mfc0 v0
, CP0_TCCONTEXT
383 * If we have a queue, provoke dispatch within the VPE by setting C_SW1
390 * This test should really never branch but
391 * let's be prudent here. Having atomized
392 * the shared register modifications, we can
393 * now EVPE, and must do so before interrupts
394 * are potentially re-enabled.
396 andi a1
, a1
, MVPCONTROL_EVP
400 /* We know that TCStatua.IXMT should be set from above */
401 xori a0
, a0
, TCSTATUS_IXMT
403 mtc0 a0
, CP0_TCSTATUS
407 #endif /* CONFIG_MIPS_MT_SMTC */
408 LONG_L v1
, PT_EPC(sp
)
410 LONG_L $
31, PT_R31(sp
)
411 LONG_L $
28, PT_R28(sp
)
412 LONG_L $
25, PT_R25(sp
)
426 .macro RESTORE_SP_AND_RET
427 LONG_L sp
, PT_R29(sp
)
436 LONG_L sp
, PT_R29(sp
)
447 .macro RESTORE_ALL_AND_RET
456 * Move to kernel mode and disable interrupts.
457 * Set cp0 enable bit as sign that we're running on the kernel stack
460 #if !defined(CONFIG_MIPS_MT_SMTC)
462 li t1
, ST0_CU0
| STATMASK
466 #else /* CONFIG_MIPS_MT_SMTC */
468 * For SMTC, we need to set privilege
469 * and disable interrupts only for the
470 * current TC, using the TCStatus register.
472 mfc0 t0
, CP0_TCSTATUS
473 /* Fortunately CU 0 is in the same place in both registers */
474 /* Set TCU0, TMX, TKSU (for later inversion) and IXMT */
475 li t1
, ST0_CU0
| 0x08001c00
477 /* Clear TKSU, leave IXMT */
479 mtc0 t0
, CP0_TCSTATUS
481 /* We need to leave the global IE bit set, but clear EXL...*/
483 ori t0
, ST0_EXL
| ST0_ERL
484 xori t0
, ST0_EXL
| ST0_ERL
486 #endif /* CONFIG_MIPS_MT_SMTC */
491 * Move to kernel mode and enable interrupts.
492 * Set cp0 enable bit as sign that we're running on the kernel stack
495 #if !defined(CONFIG_MIPS_MT_SMTC)
497 li t1
, ST0_CU0
| STATMASK
499 xori t0
, STATMASK
& ~1
501 #else /* CONFIG_MIPS_MT_SMTC */
503 * For SMTC, we need to set privilege
504 * and enable interrupts only for the
505 * current TC, using the TCStatus register.
508 mfc0 t0
, CP0_TCSTATUS
509 /* Fortunately CU 0 is in the same place in both registers */
510 /* Set TCU0, TKSU (for later inversion) and IXMT */
511 li t1
, ST0_CU0
| 0x08001c00
513 /* Clear TKSU *and* IXMT */
515 mtc0 t0
, CP0_TCSTATUS
517 /* We need to leave the global IE bit set, but clear EXL...*/
522 /* irq_enable_hazard below should expand to EHB for 24K/34K cpus */
523 #endif /* CONFIG_MIPS_MT_SMTC */
528 * Just move to kernel mode and leave interrupts as they are. Note
529 * for the R3000 this means copying the previous enable from IEp.
530 * Set cp0 enable bit as sign that we're running on the kernel stack
533 #ifdef CONFIG_MIPS_MT_SMTC
535 * This gets baroque in SMTC. We want to
536 * protect the non-atomic clearing of EXL
537 * with DMT/EMT, but we don't want to take
538 * an interrupt while DMT is still in effect.
541 /* KMODE gets invoked from both reorder and noreorder code */
545 mfc0 v0
, CP0_TCSTATUS
546 andi v1
, v0
, TCSTATUS_IXMT
547 ori v0
, TCSTATUS_IXMT
548 mtc0 v0
, CP0_TCSTATUS
552 * We don't know a priori if ra is "live"
558 #endif /* CONFIG_MIPS_MT_SMTC */
560 li t1
, ST0_CU0
| (STATMASK
& ~1)
561 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
567 xori t0
, STATMASK
& ~1
569 #ifdef CONFIG_MIPS_MT_SMTC
571 andi v0
, v0
, VPECONTROL_TE
576 mfc0 v0
, CP0_TCSTATUS
577 /* Clear IXMT, then OR in previous value */
578 ori v0
, TCSTATUS_IXMT
579 xori v0
, TCSTATUS_IXMT
581 mtc0 v0
, CP0_TCSTATUS
583 * irq_disable_hazard below should expand to EHB
587 #endif /* CONFIG_MIPS_MT_SMTC */
591 #endif /* _ASM_STACKFRAME_H */