x86/paravirt: Make read_cr2() CALLEE_SAVE
authorPeter Zijlstra <peterz@infradead.org>
Thu, 11 Jul 2019 11:40:55 +0000 (13:40 +0200)
committerThomas Gleixner <tglx@linutronix.de>
Wed, 17 Jul 2019 21:17:37 +0000 (23:17 +0200)
commit55aedddb6149ab71bec9f050846855113977b033
treed9154c2a76eea96bdb139f1862a6f0ec72613a2d
parent406de552c2be6ded524c75d14a73cf7f027f587e
x86/paravirt: Make read_cr2() CALLEE_SAVE

The one paravirt read_cr2() implementation (Xen) is actually quite trivial
and doesn't need to clobber anything other than the return register.

Making read_cr2() CALLEE_SAVE avoids all the PUSH/POP nonsense and allows
more convenient use from assembly.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: bp@alien8.de
Cc: rostedt@goodmis.org
Cc: luto@kernel.org
Cc: torvalds@linux-foundation.org
Cc: hpa@zytor.com
Cc: dave.hansen@linux.intel.com
Cc: zhe.he@windriver.com
Cc: joel@joelfernandes.org
Cc: devel@etsukata.com
Link: https://lkml.kernel.org/r/20190711114335.887392493@infradead.org
arch/x86/entry/calling.h
arch/x86/include/asm/paravirt.h
arch/x86/include/asm/paravirt_types.h
arch/x86/kernel/asm-offsets.c
arch/x86/kernel/head_64.S
arch/x86/kernel/paravirt.c
arch/x86/xen/enlighten_pv.c
arch/x86/xen/mmu_pv.c
arch/x86/xen/xen-asm.S
arch/x86/xen/xen-ops.h