From 5323180db75d562a287cb2020b07c9422df13df6 Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Sat, 14 Apr 2007 02:37:26 +0900 Subject: [MIPS] Disallow CpU exception in kernel again. The commit 4d40bff7110e9e1a97ff8c01bdd6350e9867cc10 ("Allow CpU exception in kernel partially") was broken. The commit was to fix theoretical problem but broke usual case. Revert it for now. Signed-off-by: Atsushi Nemoto Signed-off-by: Ralf Baechle --- include/asm-mips/fpu.h | 16 ---------------- 1 file changed, 16 deletions(-) (limited to 'include/asm-mips/fpu.h') diff --git a/include/asm-mips/fpu.h b/include/asm-mips/fpu.h index 4e12d1f9534f..71436f90203f 100644 --- a/include/asm-mips/fpu.h +++ b/include/asm-mips/fpu.h @@ -68,8 +68,6 @@ do { \ /* We don't care about the c0 hazard here */ \ } while (0) -#define __fpu_enabled() (read_c0_status() & ST0_CU1) - #define enable_fpu() \ do { \ if (cpu_has_fpu) \ @@ -162,18 +160,4 @@ static inline fpureg_t *get_fpu_regs(struct task_struct *tsk) return tsk->thread.fpu.fpr; } -static inline void enable_fp_in_kernel(void) -{ - set_thread_flag(TIF_ALLOW_FP_IN_KERNEL); - /* make sure CU1 and FPU ownership are consistent */ - if (!__is_fpu_owner() && __fpu_enabled()) - __disable_fpu(); -} - -static inline void disable_fp_in_kernel(void) -{ - BUG_ON(!__is_fpu_owner() && __fpu_enabled()); - clear_thread_flag(TIF_ALLOW_FP_IN_KERNEL); -} - #endif /* _ASM_FPU_H */ -- cgit v1.2.2 From faea62346444ce5b1dba8fb5291d95b676522c42 Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Mon, 16 Apr 2007 23:19:44 +0900 Subject: [MIPS] Retry {save,restore}_fp_context if failed in atomic context. The save_fp_context()/restore_fp_context() might sleep on accessing user stack and therefore might lose FPU ownership in middle of them. If these function failed due to "in_atomic" test in do_page_fault, touch the sigcontext area in non-atomic context and retry these save/restore operation. This is a replacement of a (broken) fix which was titled "Allow CpU exception in kernel partially". Signed-off-by: Atsushi Nemoto Signed-off-by: Ralf Baechle --- include/asm-mips/fpu.h | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'include/asm-mips/fpu.h') diff --git a/include/asm-mips/fpu.h b/include/asm-mips/fpu.h index 71436f90203f..b414a7d9db43 100644 --- a/include/asm-mips/fpu.h +++ b/include/asm-mips/fpu.h @@ -100,14 +100,19 @@ static inline void __own_fpu(void) set_thread_flag(TIF_USEDFPU); } -static inline void own_fpu(int restore) +static inline void own_fpu_inatomic(int restore) { - preempt_disable(); if (cpu_has_fpu && !__is_fpu_owner()) { __own_fpu(); if (restore) _restore_fp(current); } +} + +static inline void own_fpu(int restore) +{ + preempt_disable(); + own_fpu_inatomic(restore); preempt_enable(); } -- cgit v1.2.2