On Thu, 27 Apr 2006 23:29:04 +0900 (JST), Atsushi Nemoto <anemo@xxxxxxxxxxxxx> wrote: > This is actually irrelevant to kgdb. Without this fix, _save_fp() in > 64-bit kernel is seriously broken. > > ffffffff8010bec0 <_save_fp>: > ffffffff8010bec0: 400d6000 mfc0 t1,c0_status > ffffffff8010bec4: 000c7140 sll t2,t0,0x5 > ffffffff8010bec8: 05c10011 bgez t2,ffffffff8010bf10 <_save_fp+0x50> > ffffffff8010becc: 00000000 nop > ffffffff8010bed0: f4810328 sdc1 $f1,808(a0) > ... ping. Fix register usage in fpu_save_double() and make fpu_restore_double() more symmetric with fpu_save_double(). Signed-off-by: Atsushi Nemoto <anemo@xxxxxxxxxxxxx> diff --git a/arch/mips/kernel/r4k_switch.S b/arch/mips/kernel/r4k_switch.S index 0b1b54a..db94e55 100644 --- a/arch/mips/kernel/r4k_switch.S +++ b/arch/mips/kernel/r4k_switch.S @@ -75,8 +75,8 @@ and t0, t0, t1 LONG_S t0, ST_OFF(t3) - fpu_save_double a0 t1 t0 t2 # c0_status passed in t1 - # clobbers t0 and t2 + fpu_save_double a0 t0 t1 # c0_status passed in t0 + # clobbers t1 1: /* @@ -129,9 +129,9 @@ */ LEAF(_save_fp) #ifdef CONFIG_64BIT - mfc0 t1, CP0_STATUS + mfc0 t0, CP0_STATUS #endif - fpu_save_double a0 t1 t0 t2 # clobbers t1 + fpu_save_double a0 t0 t1 # clobbers t1 jr ra END(_save_fp) @@ -139,7 +139,10 @@ LEAF(_save_fp) * Restore a thread's fp context. */ LEAF(_restore_fp) - fpu_restore_double a0, t1 # clobbers t1 +#ifdef CONFIG_64BIT + mfc0 t0, CP0_STATUS +#endif + fpu_restore_double a0 t0 t1 # clobbers t1 jr ra END(_restore_fp) diff --git a/include/asm-mips/asmmacro-32.h b/include/asm-mips/asmmacro-32.h index 11daf5c..5de3963 100644 --- a/include/asm-mips/asmmacro-32.h +++ b/include/asm-mips/asmmacro-32.h @@ -12,7 +12,7 @@ #include <asm/fpregdef.h> #include <asm/mipsregs.h> - .macro fpu_save_double thread status tmp1=t0 tmp2 + .macro fpu_save_double thread status tmp1=t0 cfc1 \tmp1, fcr31 sdc1 $f0, THREAD_FPR0(\thread) sdc1 $f2, THREAD_FPR2(\thread) @@ -70,7 +70,7 @@ sw \tmp, THREAD_FCR31(\thread) .endm - .macro fpu_restore_double thread tmp=t0 + .macro fpu_restore_double thread status tmp=t0 lw \tmp, THREAD_FCR31(\thread) ldc1 $f0, THREAD_FPR0(\thread) ldc1 $f2, THREAD_FPR2(\thread) diff --git a/include/asm-mips/asmmacro-64.h b/include/asm-mips/asmmacro-64.h index 559c355..225feef 100644 --- a/include/asm-mips/asmmacro-64.h +++ b/include/asm-mips/asmmacro-64.h @@ -53,12 +53,12 @@ sdc1 $f31, THREAD_FPR31(\thread) .endm - .macro fpu_save_double thread status tmp1 tmp2 - sll \tmp2, \tmp1, 5 - bgez \tmp2, 2f + .macro fpu_save_double thread status tmp + sll \tmp, \status, 5 + bgez \tmp, 2f fpu_save_16odd \thread 2: - fpu_save_16even \thread \tmp1 # clobbers t1 + fpu_save_16even \thread \tmp .endm .macro fpu_restore_16even thread tmp=t0 @@ -101,13 +101,12 @@ ldc1 $f31, THREAD_FPR31(\thread) .endm - .macro fpu_restore_double thread tmp - mfc0 t0, CP0_STATUS - sll t1, t0, 5 - bgez t1, 1f # 16 register mode? + .macro fpu_restore_double thread status tmp + sll \tmp, \status, 5 + bgez \tmp, 1f # 16 register mode? - fpu_restore_16odd a0 -1: fpu_restore_16even a0, t0 # clobbers t0 + fpu_restore_16odd \thread +1: fpu_restore_16even \thread \tmp .endm .macro cpu_save_nonscratch thread
