diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2017-12-05 13:34:51 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-12-22 20:13:03 +0100 |
| commit | 23cb7d46f371844c004784ad9552a57446f73e5a (patch) | |
| tree | dd20a872135a37d11436300ef93e099ec62b7d54 /arch | |
| parent | 3e46e0f5ee3643a1239be9046c7ba6c66ca2b329 (diff) | |
| download | linux-23cb7d46f371844c004784ad9552a57446f73e5a.tar.bz2 | |
x86/microcode: Dont abuse the TLB-flush interface
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 a precaution and the SDM doesn't mention anything like
this, take it out back.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: fenghua.yu@intel.com
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/tlbflush.h | 19 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/microcode/intel.c | 13 |
2 files changed, 6 insertions, 26 deletions
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h index 509046cfa5ce..c2e45da4e540 100644 --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -246,20 +246,9 @@ static inline void __native_flush_tlb(void) 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)) { /* @@ -277,7 +266,11 @@ static inline void __native_flush_tlb_global(void) */ 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); } diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c index 7dbcb7adf797..8ccdca6d3f9e 100644 --- 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_info *uci) } #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 ucode_cpu_info *uci, bool early) 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) |