1 files changed, 50 insertions, 0 deletions

diff --git a/arch/x86/include/asm/calling.h b/arch/x86/include/asm/calling.h
index 0fa675033912..cb4c73bfeb48 100644
--- a/arch/x86/include/asm/calling.h
+++ b/arch/x86/include/asm/calling.h
@@ -48,6 +48,8 @@ For 32-bit we have the following conventions - kernel is built with
 
 #include <asm/dwarf2.h>
 
+#ifdef CONFIG_X86_64
+
 /*
  * 64-bit system call stack frame layout defines and helpers,
  * for assembly code:
@@ -192,3 +194,51 @@ For 32-bit we have the following conventions - kernel is built with
         .macro icebp
         .byte 0xf1
         .endm
+
+#else /* CONFIG_X86_64 */
+
+/*
+ * For 32bit only simplified versions of SAVE_ALL/RESTORE_ALL. These
+ * are different from the entry_32.S versions in not changing the segment
+ * registers. So only suitable for in kernel use, not when transitioning
+ * from or to user space. The resulting stack frame is not a standard
+ * pt_regs frame. The main use case is calling C code from assembler
+ * when all the registers need to be preserved.
+ */
+
+        .macro SAVE_ALL
+        pushl_cfi %eax
+        CFI_REL_OFFSET eax, 0
+        pushl_cfi %ebp
+        CFI_REL_OFFSET ebp, 0
+        pushl_cfi %edi
+        CFI_REL_OFFSET edi, 0
+        pushl_cfi %esi
+        CFI_REL_OFFSET esi, 0
+        pushl_cfi %edx
+        CFI_REL_OFFSET edx, 0
+        pushl_cfi %ecx
+        CFI_REL_OFFSET ecx, 0
+        pushl_cfi %ebx
+        CFI_REL_OFFSET ebx, 0
+        .endm
+
+        .macro RESTORE_ALL
+        popl_cfi %ebx
+        CFI_RESTORE ebx
+        popl_cfi %ecx
+        CFI_RESTORE ecx
+        popl_cfi %edx
+        CFI_RESTORE edx
+        popl_cfi %esi
+        CFI_RESTORE esi
+        popl_cfi %edi
+        CFI_RESTORE edi
+        popl_cfi %ebp
+        CFI_RESTORE ebp
+        popl_cfi %eax
+        CFI_RESTORE eax
+        .endm
+
+#endif /* CONFIG_X86_64 */
+