[PATCH 4/5] x86/mm/kaiser: Remove superfluous SWITCH_TO_KERNEL

[Peter Zijlstra]

We never use this code-path with KAISER enabled.

Fixes: ("Prepare the x86/entry assembly code for entry/exit CR3 switching")
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
 arch/x86/entry/entry_64.S |    8 --------
 1 file changed, 8 deletions(-)

--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -201,14 +201,6 @@ ENTRY(entry_SYSCALL_64)
 
 	swapgs
 	movq	%rsp, PER_CPU_VAR(rsp_scratch)
-
-	/*
-	 * The kernel CR3 is needed to map the process stack, but we
-	 * need a scratch register to be able to load CR3.  %rsp is
-	 * clobberable right now, so use it as a scratch register.
-	 * %rsp will look crazy here for a couple instructions.
-	 */
-	SWITCH_TO_KERNEL_CR3 scratch_reg=%rsp
 	movq	PER_CPU_VAR(cpu_current_top_of_stack), %rsp
 
 	/* Construct struct pt_regs on stack */