Commit ec400ddeff20 ("x86/microcode_intel_early.c: Early update ucode on Intel's CPU") grubbed into tlbflush internals without coherent explanation. Since it says its precaution and the SDM doesn't mention anything like this, take it out back. Cc: hpa@zytor.com Cc: fenghua.yu@intel.com Cc: bp@alien8.de Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/include/asm/tlbflush.h | 19 ++++++------------- arch/x86/kernel/cpu/microcode/intel.c | 13 ------------- 2 files changed, 6 insertions(+), 26 deletions(-) --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -394,20 +394,9 @@ static inline void __native_flush_tlb(vo preempt_enable(); } -static inline void __native_flush_tlb_global_irq_disabled(void) -{ - unsigned long cr4; - - cr4 = this_cpu_read(cpu_tlbstate.cr4); - /* clear PGE */ - native_write_cr4(cr4 & ~X86_CR4_PGE); - /* write old PGE again and flush TLBs */ - native_write_cr4(cr4); -} - static inline void __native_flush_tlb_global(void) { - unsigned long flags; + unsigned long cr4, flags; if (static_cpu_has(X86_FEATURE_INVPCID)) { /* @@ -427,7 +416,11 @@ static inline void __native_flush_tlb_gl */ raw_local_irq_save(flags); - __native_flush_tlb_global_irq_disabled(); + cr4 = this_cpu_read(cpu_tlbstate.cr4); + /* toggle PGE */ + native_write_cr4(cr4 ^ X86_CR4_PGE); + /* write old PGE again and flush TLBs */ + native_write_cr4(cr4); raw_local_irq_restore(flags); } --- a/arch/x86/kernel/cpu/microcode/intel.c +++ b/arch/x86/kernel/cpu/microcode/intel.c @@ -565,15 +565,6 @@ static void print_ucode(struct ucode_cpu } #else -/* - * Flush global tlb. We only do this in x86_64 where paging has been enabled - * already and PGE should be enabled as well. - */ -static inline void flush_tlb_early(void) -{ - __native_flush_tlb_global_irq_disabled(); -} - static inline void print_ucode(struct ucode_cpu_info *uci) { struct microcode_intel *mc; @@ -602,10 +593,6 @@ static int apply_microcode_early(struct if (rev != mc->hdr.rev) return -1; -#ifdef CONFIG_X86_64 - /* Flush global tlb. This is precaution. */ - flush_tlb_early(); -#endif uci->cpu_sig.rev = rev; if (early)