x86/mm: Rename flush_tlb_single() and flush_tlb_one() to __flush_tlb_one_[user|kernel]()

[mirror_ubuntu-bionic-kernel.git] / arch / x86 / include / asm / tlbflush.h

diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index 2b8f18ca58747ae40b515c2bf674f8faced147e8..84137c22fdfade9bc8224c317808b311ec6f3007 100644 (file)
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -140,7 +140,7 @@ static inline unsigned long build_cr3_noflush(pgd_t *pgd, u16 asid)
 #else
 #define __flush_tlb() __native_flush_tlb()
 #define __flush_tlb_global() __native_flush_tlb_global()
-#define __flush_tlb_single(addr) __native_flush_tlb_single(addr)
+#define __flush_tlb_one_user(addr) __native_flush_tlb_one_user(addr)
 #endif
 
 static inline bool tlb_defer_switch_to_init_mm(void)
@@ -400,7 +400,7 @@ static inline void __native_flush_tlb_global(void)
 /*
  * flush one page in the user mapping
  */
-static inline void __native_flush_tlb_single(unsigned long addr)
+static inline void __native_flush_tlb_one_user(unsigned long addr)
 {
        u32 loaded_mm_asid = this_cpu_read(cpu_tlbstate.loaded_mm_asid);
 
@@ -437,18 +437,31 @@ static inline void __flush_tlb_all(void)
 /*
  * flush one page in the kernel mapping
  */
-static inline void __flush_tlb_one(unsigned long addr)
+static inline void __flush_tlb_one_kernel(unsigned long addr)
 {
        count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ONE);
-       __flush_tlb_single(addr);
+
+       /*
+        * If PTI is off, then __flush_tlb_one_user() is just INVLPG or its
+        * paravirt equivalent.  Even with PCID, this is sufficient: we only
+        * use PCID if we also use global PTEs for the kernel mapping, and
+        * INVLPG flushes global translations across all address spaces.
+        *
+        * If PTI is on, then the kernel is mapped with non-global PTEs, and
+        * __flush_tlb_one_user() will flush the given address for the current
+        * kernel address space and for its usermode counterpart, but it does
+        * not flush it for other address spaces.
+        */
+       __flush_tlb_one_user(addr);
 
        if (!static_cpu_has(X86_FEATURE_PTI))
                return;
 
        /*
-        * __flush_tlb_single() will have cleared the TLB entry for this ASID,
-        * but since kernel space is replicated across all, we must also
-        * invalidate all others.
+        * See above.  We need to propagate the flush to all other address
+        * spaces.  In principle, we only need to propagate it to kernelmode
+        * address spaces, but the extra bookkeeping we would need is not
+        * worth it.
         */
        invalidate_other_asid();
 }