| /* |
| * This file is subject to the terms and conditions of the GNU General Public |
| * License. See the file "COPYING" in the main directory of this archive |
| * for more details. |
| * |
| * Copyright (C) 1994, 1995, 1996, 1998, 1999, 2002, 2003 Ralf Baechle |
| * Copyright (C) 1996 David S. Miller (davem@davemloft.net) |
| * Copyright (C) 1994, 1995, 1996, by Andreas Busse |
| * Copyright (C) 1999 Silicon Graphics, Inc. |
| * Copyright (C) 2000 MIPS Technologies, Inc. |
| * written by Carsten Langgaard, carstenl@mips.com |
| */ |
| #include <asm/asm.h> |
| #include <asm/cachectl.h> |
| #include <asm/fpregdef.h> |
| #include <asm/mipsregs.h> |
| #include <asm/asm-offsets.h> |
| #include <asm/pgtable-bits.h> |
| #include <asm/regdef.h> |
| #include <asm/stackframe.h> |
| #include <asm/thread_info.h> |
| |
| #include <asm/asmmacro.h> |
| |
| /* |
| * Offset to the current process status flags, the first 32 bytes of the |
| * stack are not used. |
| */ |
| #define ST_OFF (_THREAD_SIZE - 32 - PT_SIZE + PT_STATUS) |
| |
| /* |
| * FPU context is saved iff the process has used it's FPU in the current |
| * time slice as indicated by _TIF_USEDFPU. In any case, the CU1 bit for user |
| * space STATUS register should be 0, so that a process *always* starts its |
| * userland with FPU disabled after each context switch. |
| * |
| * FPU will be enabled as soon as the process accesses FPU again, through |
| * do_cpu() trap. |
| */ |
| |
| /* |
| * task_struct *resume(task_struct *prev, task_struct *next, |
| * struct thread_info *next_ti, int usedfpu) |
| */ |
| .align 5 |
| LEAF(resume) |
| mfc0 t1, CP0_STATUS |
| LONG_S t1, THREAD_STATUS(a0) |
| cpu_save_nonscratch a0 |
| LONG_S ra, THREAD_REG31(a0) |
| |
| /* |
| * check if we need to save FPU registers |
| */ |
| |
| beqz a3, 1f |
| |
| PTR_L t3, TASK_THREAD_INFO(a0) |
| /* |
| * clear saved user stack CU1 bit |
| */ |
| LONG_L t0, ST_OFF(t3) |
| li t1, ~ST0_CU1 |
| and t0, t0, t1 |
| LONG_S t0, ST_OFF(t3) |
| |
| fpu_save_double a0 t0 t1 # c0_status passed in t0 |
| # clobbers t1 |
| 1: |
| |
| #if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP) |
| PTR_L t8, __stack_chk_guard |
| LONG_L t9, TASK_STACK_CANARY(a1) |
| LONG_S t9, 0(t8) |
| #endif |
| |
| /* |
| * The order of restoring the registers takes care of the race |
| * updating $28, $29 and kernelsp without disabling ints. |
| */ |
| move $28, a2 |
| cpu_restore_nonscratch a1 |
| |
| PTR_ADDU t0, $28, _THREAD_SIZE - 32 |
| set_saved_sp t0, t1, t2 |
| #ifdef CONFIG_MIPS_MT_SMTC |
| /* Read-modify-writes of Status must be atomic on a VPE */ |
| mfc0 t2, CP0_TCSTATUS |
| ori t1, t2, TCSTATUS_IXMT |
| mtc0 t1, CP0_TCSTATUS |
| andi t2, t2, TCSTATUS_IXMT |
| _ehb |
| DMT 8 # dmt t0 |
| move t1,ra |
| jal mips_ihb |
| move ra,t1 |
| #endif /* CONFIG_MIPS_MT_SMTC */ |
| mfc0 t1, CP0_STATUS /* Do we really need this? */ |
| li a3, 0xff01 |
| and t1, a3 |
| LONG_L a2, THREAD_STATUS(a1) |
| nor a3, $0, a3 |
| and a2, a3 |
| or a2, t1 |
| mtc0 a2, CP0_STATUS |
| #ifdef CONFIG_MIPS_MT_SMTC |
| _ehb |
| andi t0, t0, VPECONTROL_TE |
| beqz t0, 1f |
| emt |
| 1: |
| mfc0 t1, CP0_TCSTATUS |
| xori t1, t1, TCSTATUS_IXMT |
| or t1, t1, t2 |
| mtc0 t1, CP0_TCSTATUS |
| _ehb |
| #endif /* CONFIG_MIPS_MT_SMTC */ |
| move v0, a0 |
| jr ra |
| END(resume) |
| |
| /* |
| * Save a thread's fp context. |
| */ |
| LEAF(_save_fp) |
| #ifdef CONFIG_64BIT |
| mfc0 t0, CP0_STATUS |
| #endif |
| fpu_save_double a0 t0 t1 # clobbers t1 |
| jr ra |
| END(_save_fp) |
| |
| /* |
| * Restore a thread's fp context. |
| */ |
| LEAF(_restore_fp) |
| #ifdef CONFIG_64BIT |
| mfc0 t0, CP0_STATUS |
| #endif |
| fpu_restore_double a0 t0 t1 # clobbers t1 |
| jr ra |
| END(_restore_fp) |
| |
| /* |
| * Load the FPU with signalling NANS. This bit pattern we're using has |
| * the property that no matter whether considered as single or as double |
| * precision represents signaling NANS. |
| * |
| * We initialize fcr31 to rounding to nearest, no exceptions. |
| */ |
| |
| #define FPU_DEFAULT 0x00000000 |
| |
| LEAF(_init_fpu) |
| #ifdef CONFIG_MIPS_MT_SMTC |
| /* Rather than manipulate per-VPE Status, set per-TC bit in TCStatus */ |
| mfc0 t0, CP0_TCSTATUS |
| /* Bit position is the same for Status, TCStatus */ |
| li t1, ST0_CU1 |
| or t0, t1 |
| mtc0 t0, CP0_TCSTATUS |
| #else /* Normal MIPS CU1 enable */ |
| mfc0 t0, CP0_STATUS |
| li t1, ST0_CU1 |
| or t0, t1 |
| mtc0 t0, CP0_STATUS |
| #endif /* CONFIG_MIPS_MT_SMTC */ |
| enable_fpu_hazard |
| |
| li t1, FPU_DEFAULT |
| ctc1 t1, fcr31 |
| |
| li t1, -1 # SNaN |
| |
| #ifdef CONFIG_64BIT |
| sll t0, t0, 5 |
| bgez t0, 1f # 16 / 32 register mode? |
| |
| dmtc1 t1, $f1 |
| dmtc1 t1, $f3 |
| dmtc1 t1, $f5 |
| dmtc1 t1, $f7 |
| dmtc1 t1, $f9 |
| dmtc1 t1, $f11 |
| dmtc1 t1, $f13 |
| dmtc1 t1, $f15 |
| dmtc1 t1, $f17 |
| dmtc1 t1, $f19 |
| dmtc1 t1, $f21 |
| dmtc1 t1, $f23 |
| dmtc1 t1, $f25 |
| dmtc1 t1, $f27 |
| dmtc1 t1, $f29 |
| dmtc1 t1, $f31 |
| 1: |
| #endif |
| |
| #ifdef CONFIG_CPU_MIPS32 |
| mtc1 t1, $f0 |
| mtc1 t1, $f1 |
| mtc1 t1, $f2 |
| mtc1 t1, $f3 |
| mtc1 t1, $f4 |
| mtc1 t1, $f5 |
| mtc1 t1, $f6 |
| mtc1 t1, $f7 |
| mtc1 t1, $f8 |
| mtc1 t1, $f9 |
| mtc1 t1, $f10 |
| mtc1 t1, $f11 |
| mtc1 t1, $f12 |
| mtc1 t1, $f13 |
| mtc1 t1, $f14 |
| mtc1 t1, $f15 |
| mtc1 t1, $f16 |
| mtc1 t1, $f17 |
| mtc1 t1, $f18 |
| mtc1 t1, $f19 |
| mtc1 t1, $f20 |
| mtc1 t1, $f21 |
| mtc1 t1, $f22 |
| mtc1 t1, $f23 |
| mtc1 t1, $f24 |
| mtc1 t1, $f25 |
| mtc1 t1, $f26 |
| mtc1 t1, $f27 |
| mtc1 t1, $f28 |
| mtc1 t1, $f29 |
| mtc1 t1, $f30 |
| mtc1 t1, $f31 |
| #else |
| .set mips3 |
| dmtc1 t1, $f0 |
| dmtc1 t1, $f2 |
| dmtc1 t1, $f4 |
| dmtc1 t1, $f6 |
| dmtc1 t1, $f8 |
| dmtc1 t1, $f10 |
| dmtc1 t1, $f12 |
| dmtc1 t1, $f14 |
| dmtc1 t1, $f16 |
| dmtc1 t1, $f18 |
| dmtc1 t1, $f20 |
| dmtc1 t1, $f22 |
| dmtc1 t1, $f24 |
| dmtc1 t1, $f26 |
| dmtc1 t1, $f28 |
| dmtc1 t1, $f30 |
| #endif |
| jr ra |
| END(_init_fpu) |
