[PATCH v3 13/16] x86/paravirt: Prepare support of MSR instruction interfaces

[Juergen Gross]

Make the paravirt callee-save infrastructure more generic by allowing
arbitrary register interfaces via prologue and epilogue helper macros.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
V3:
- carved out from patch 5 of V1
---
 arch/x86/include/asm/paravirt_types.h     | 43 ++++++++++++++---------
 arch/x86/include/asm/qspinlock_paravirt.h |  4 +--
 2 files changed, 29 insertions(+), 18 deletions(-)

diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index 1e7188247c1f..999a5abe54ed 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -457,27 +457,38 @@ extern struct paravirt_patch_template pv_ops;
 #define PV_SAVE_ALL_CALLER_REGS		"pushl %ecx;"
 #define PV_RESTORE_ALL_CALLER_REGS	"popl  %ecx;"
 #else
+/* Save and restore caller-save registers, except %rax, %rcx and %rdx. */
+#define PV_SAVE_COMMON_CALLER_REGS	\
+	"push %rsi;"			\
+	"push %rdi;"			\
+	"push %r8;"			\
+	"push %r9;"			\
+	"push %r10;"			\
+	"push %r11;"
+
+#define PV_RESTORE_COMMON_CALLER_REGS	\
+	"pop %r11;"			\
+	"pop %r10;"			\
+	"pop %r9;"			\
+	"pop %r8;"			\
+	"pop %rdi;"			\
+	"pop %rsi;"
+
 /* save and restore all caller-save registers, except return value */
 #define PV_SAVE_ALL_CALLER_REGS						\
 	"push %rcx;"							\
 	"push %rdx;"							\
-	"push %rsi;"							\
-	"push %rdi;"							\
-	"push %r8;"							\
-	"push %r9;"							\
-	"push %r10;"							\
-	"push %r11;"
+	PV_SAVE_COMMON_CALLER_REGS
+
 #define PV_RESTORE_ALL_CALLER_REGS					\
-	"pop %r11;"							\
-	"pop %r10;"							\
-	"pop %r9;"							\
-	"pop %r8;"							\
-	"pop %rdi;"							\
-	"pop %rsi;"							\
+	PV_RESTORE_COMMON_CALLER_REGS					\
 	"pop %rdx;"							\
 	"pop %rcx;"
 #endif
 
+#define PV_PROLOGUE_ALL(func)	PV_SAVE_ALL_CALLER_REGS
+#define PV_EPILOGUE_ALL(func)	PV_RESTORE_ALL_CALLER_REGS
+
 /*
  * Generate a thunk around a function which saves all caller-save
  * registers except for the return value.  This allows C functions to
@@ -491,7 +502,7 @@ extern struct paravirt_patch_template pv_ops;
  * functions.
  */
 #define PV_THUNK_NAME(func) "__raw_callee_save_" #func
-#define __PV_CALLEE_SAVE_REGS_THUNK(func, section)			\
+#define __PV_CALLEE_SAVE_REGS_THUNK(func, section, helper)		\
 	extern typeof(func) __raw_callee_save_##func;			\
 									\
 	asm(".pushsection " section ", \"ax\";"				\
@@ -501,16 +512,16 @@ extern struct paravirt_patch_template pv_ops;
 	    PV_THUNK_NAME(func) ":"					\
 	    ASM_ENDBR							\
 	    FRAME_BEGIN							\
-	    PV_SAVE_ALL_CALLER_REGS					\
+	    PV_PROLOGUE_##helper(func)					\
 	    "call " #func ";"						\
-	    PV_RESTORE_ALL_CALLER_REGS					\
+	    PV_EPILOGUE_##helper(func)					\
 	    FRAME_END							\
 	    ASM_RET							\
 	    ".size " PV_THUNK_NAME(func) ", .-" PV_THUNK_NAME(func) ";"	\
 	    ".popsection")
 
 #define PV_CALLEE_SAVE_REGS_THUNK(func)			\
-	__PV_CALLEE_SAVE_REGS_THUNK(func, ".text")
+	__PV_CALLEE_SAVE_REGS_THUNK(func, ".text", ALL)
 
 /* Get a reference to a callee-save function */
 #define PV_CALLEE_SAVE(func)						\
diff --git a/arch/x86/include/asm/qspinlock_paravirt.h b/arch/x86/include/asm/qspinlock_paravirt.h
index 0a985784be9b..002b17f0735e 100644
--- a/arch/x86/include/asm/qspinlock_paravirt.h
+++ b/arch/x86/include/asm/qspinlock_paravirt.h
@@ -14,7 +14,7 @@ void __lockfunc __pv_queued_spin_unlock_slowpath(struct qspinlock *lock, u8 lock
  */
 #ifdef CONFIG_64BIT
 
-__PV_CALLEE_SAVE_REGS_THUNK(__pv_queued_spin_unlock_slowpath, ".spinlock.text");
+__PV_CALLEE_SAVE_REGS_THUNK(__pv_queued_spin_unlock_slowpath, ".spinlock.text", ALL);
 #define __pv_queued_spin_unlock	__pv_queued_spin_unlock
 
 /*
@@ -61,7 +61,7 @@ DEFINE_ASM_FUNC(__raw_callee_save___pv_queued_spin_unlock,
 #else /* CONFIG_64BIT */
 
 extern void __lockfunc __pv_queued_spin_unlock(struct qspinlock *lock);
-__PV_CALLEE_SAVE_REGS_THUNK(__pv_queued_spin_unlock, ".spinlock.text");
+__PV_CALLEE_SAVE_REGS_THUNK(__pv_queued_spin_unlock, ".spinlock.text", ALL);
 
 #endif /* CONFIG_64BIT */
 #endif
-- 
2.53.0