From 8c938f9fae887f6e180bf802aa1c33cf74712aff Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 20 Feb 2009 22:12:18 +0100 Subject: [PATCH] x86, mm: fault.c, factor out the vm86 fault check Impact: cleanup Instead of an ugly, open-coded, #ifdef-ed vm86 related legacy check in do_page_fault(), put it into the check_v8086_mode() helper function and merge it with an existing #ifdef. Also, simplify the code flow a tiny bit in the helper. No code changed: arch/x86/mm/fault.o: text data bss dec hex filename 2711 12 12 2735 aaf fault.o.before 2711 12 12 2735 aaf fault.o.after Cc: Linus Torvalds Signed-off-by: Ingo Molnar --- arch/x86/mm/fault.c | 43 +++++++++++++++++++++++++++++++------------ 1 file changed, 31 insertions(+), 12 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 72973c7682ba..7dc0615c3cfe 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -328,14 +328,41 @@ static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address) return pmd_k; } -#endif -#ifdef CONFIG_X86_64 +/* + * Did it hit the DOS screen memory VA from vm86 mode? + */ +static inline void +check_v8086_mode(struct pt_regs *regs, unsigned long address, + struct task_struct *tsk) +{ + unsigned long bit; + + if (!v8086_mode(regs)) + return; + + bit = (address - 0xA0000) >> PAGE_SHIFT; + if (bit < 32) + tsk->thread.screen_bitmap |= 1 << bit; +} + +#else /* CONFIG_X86_64: */ + static const char errata93_warning[] = KERN_ERR "******* Your BIOS seems to not contain a fix for K8 errata #93\n" KERN_ERR "******* Working around it, but it may cause SEGVs or burn power.\n" KERN_ERR "******* Please consider a BIOS update.\n" KERN_ERR "******* Disabling USB legacy in the BIOS may also help.\n"; + +/* + * No vm86 mode in 64-bit mode: + */ +static inline void +check_v8086_mode(struct pt_regs *regs, unsigned long address, + struct task_struct *tsk) +{ +} + #endif /* @@ -1091,16 +1118,8 @@ good_area: else tsk->min_flt++; -#ifdef CONFIG_X86_32 - /* - * Did it hit the DOS screen memory VA from vm86 mode? - */ - if (v8086_mode(regs)) { - unsigned long bit = (address - 0xA0000) >> PAGE_SHIFT; - if (bit < 32) - tsk->thread.screen_bitmap |= 1 << bit; - } -#endif + check_v8086_mode(regs, address, tsk); + up_read(&mm->mmap_sem); } -- 2.20.1