[PATCH V2 7/7] x86/entry: Convert SWAPGS to swapgs and remove the definition of SWAPGS

[Lai Jiangshan <jiangshanlai@xxxxxxxxx>]

From: Lai Jiangshan <jiangshan.ljs@xxxxxxxxxxxx>

XENPV doesn't use swapgs_restore_regs_and_return_to_usermode(),
error_entry() and entry_SYSENTER_compat(), so the PV-awared SWAPGS in
them can be changed to swapgs.  There is no user of the SWAPGS anymore
after this change.

The INTERRUPT_RETURN in swapgs_restore_regs_and_return_to_usermode()
is also converted.

Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Lai Jiangshan <jiangshan.ljs@xxxxxxxxxxxx>
---
 arch/x86/entry/entry_64.S        | 10 +++++-----
 arch/x86/entry/entry_64_compat.S |  2 +-
 arch/x86/include/asm/irqflags.h  |  2 --
 3 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 88b61f310289..d9c885400034 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -644,8 +644,8 @@ SYM_INNER_LABEL(swapgs_restore_regs_and_return_to_usermode, 
SYM_L_GLOBAL)
 
        /* Restore RDI. */
        popq    %rdi
-       SWAPGS
-       INTERRUPT_RETURN
+       swapgs
+       jmp     native_iret
 
 
 SYM_INNER_LABEL(restore_regs_and_return_to_kernel, SYM_L_GLOBAL)
@@ -1007,7 +1007,7 @@ SYM_CODE_START_LOCAL(error_entry)
         * We entered from user mode or we're pretending to have entered
         * from user mode due to an IRET fault.
         */
-       SWAPGS
+       swapgs
        FENCE_SWAPGS_USER_ENTRY
        /* We have user CR3.  Change to kernel CR3. */
        SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
@@ -1039,7 +1039,7 @@ SYM_CODE_START_LOCAL(error_entry)
         * gsbase and proceed.  We'll fix up the exception and land in
         * .Lgs_change's error handler with kernel gsbase.
         */
-       SWAPGS
+       swapgs
 
        /*
         * Issue an LFENCE to prevent GS speculation, regardless of whether it 
is a
@@ -1060,7 +1060,7 @@ SYM_CODE_START_LOCAL(error_entry)
         * We came from an IRET to user mode, so we have user
         * gsbase and CR3.  Switch to kernel gsbase and CR3:
         */
-       SWAPGS
+       swapgs
        FENCE_SWAPGS_USER_ENTRY
        SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
 
diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
index a4fcea0cab14..72e017c3941f 100644
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -49,7 +49,7 @@
 SYM_CODE_START(entry_SYSENTER_compat)
        UNWIND_HINT_EMPTY
        /* Interrupts are off on entry. */
-       SWAPGS
+       swapgs
 
        pushq   %rax
        SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h
index 87761396e8cc..ac2e4cc47210 100644
--- a/arch/x86/include/asm/irqflags.h
+++ b/arch/x86/include/asm/irqflags.h
@@ -140,13 +140,11 @@ static __always_inline void 
arch_local_irq_restore(unsigned long flags)
 #else
 #ifdef CONFIG_X86_64
 #ifdef CONFIG_XEN_PV
-#define SWAPGS ALTERNATIVE "swapgs", "", X86_FEATURE_XENPV
 #define INTERRUPT_RETURN                                               \
        ANNOTATE_RETPOLINE_SAFE;                                        \
        ALTERNATIVE_TERNARY("jmp *paravirt_iret(%rip);",                \
                X86_FEATURE_XENPV, "jmp xen_iret;", "jmp native_iret;")
 #else
-#define SWAPGS swapgs
 #define INTERRUPT_RETURN       jmp native_iret
 #endif
 #endif
-- 
2.19.1.6.gb485710b