diff mbox series

[v4,3/5] x86/gsseg: make asm_load_gs_index() take an u16

Message ID 20221019102310.1543-4-xin3.li@intel.com
State New
Headers
Series x86: Enable LKGS instruction |

Commit Message

Li, Xin3 Oct. 19, 2022, 10:23 a.m. UTC 
  From: "H. Peter Anvin (Intel)" <hpa@zytor.com>

Let gcc know that only the low 16 bits of load_gs_index() argument
actually matter. It might allow it to create slightly better
code. However, do not propagate this into the prototypes of functions
that end up being paravirtualized, to avoid unnecessary changes.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
---
 arch/x86/entry/entry_64.S            | 2 +-
 arch/x86/include/asm/special_insns.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 9953d966d124..e0c48998d2fb 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -779,7 +779,7 @@  _ASM_NOKPROBE(common_interrupt_return)
 
 /*
  * Reload gs selector with exception handling
- * edi:  new selector
+ *  di:  new selector
  *
  * Is in entry.text as it shouldn't be instrumented.
  */
diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h
index 35f709f619fb..a71d0e8d4684 100644
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -120,7 +120,7 @@  static inline void native_wbinvd(void)
 	asm volatile("wbinvd": : :"memory");
 }
 
-extern asmlinkage void asm_load_gs_index(unsigned int selector);
+extern asmlinkage void asm_load_gs_index(u16 selector);
 
 static inline void native_load_gs_index(unsigned int selector)
 {