linux_dsm_epyc7002/arch/x86/xen/xen-asm.S
Juergen Gross edcb5cf84f x86/paravirt/xen: Remove xen_patch()
Xen's paravirt patch function xen_patch() does some special casing for
irq_ops functions to apply relocations when those functions can be
patched inline instead of calls.

Unfortunately none of the special case function replacements is small
enough to be patched inline, so the special case never applies.

As xen_patch() will call paravirt_patch_default() in all cases it can
be just dropped. xen-asm.h doesn't seem necessary without xen_patch()
as the only thing left in it would be the definition of XEN_EFLAGS_NMI
used only once. So move that definition and remove xen-asm.h.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boris.ostrovsky@oracle.com
Cc: lguest@lists.ozlabs.org
Cc: rusty@rustcorp.com.au
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20170816173157.8633-2-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-24 09:57:24 +02:00

137 lines
3.1 KiB
ArmAsm

/*
* Asm versions of Xen pv-ops, suitable for direct use.
*
* We only bother with direct forms (ie, vcpu in percpu data) of the
* operations here; the indirect forms are better handled in C.
*/
#include <asm/asm-offsets.h>
#include <asm/percpu.h>
#include <asm/processor-flags.h>
#include <asm/frame.h>
#include <linux/linkage.h>
/*
* Enable events. This clears the event mask and tests the pending
* event status with one and operation. If there are pending events,
* then enter the hypervisor to get them handled.
*/
ENTRY(xen_irq_enable_direct)
FRAME_BEGIN
/* Unmask events */
movb $0, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask
/*
* Preempt here doesn't matter because that will deal with any
* pending interrupts. The pending check may end up being run
* on the wrong CPU, but that doesn't hurt.
*/
/* Test for pending */
testb $0xff, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_pending
jz 1f
call check_events
1:
FRAME_END
ret
ENDPROC(xen_irq_enable_direct)
/*
* Disabling events is simply a matter of making the event mask
* non-zero.
*/
ENTRY(xen_irq_disable_direct)
movb $1, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask
ret
ENDPROC(xen_irq_disable_direct)
/*
* (xen_)save_fl is used to get the current interrupt enable status.
* Callers expect the status to be in X86_EFLAGS_IF, and other bits
* may be set in the return value. We take advantage of this by
* making sure that X86_EFLAGS_IF has the right value (and other bits
* in that byte are 0), but other bits in the return value are
* undefined. We need to toggle the state of the bit, because Xen and
* x86 use opposite senses (mask vs enable).
*/
ENTRY(xen_save_fl_direct)
testb $0xff, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask
setz %ah
addb %ah, %ah
ret
ENDPROC(xen_save_fl_direct)
/*
* In principle the caller should be passing us a value return from
* xen_save_fl_direct, but for robustness sake we test only the
* X86_EFLAGS_IF flag rather than the whole byte. After setting the
* interrupt mask state, it checks for unmasked pending events and
* enters the hypervisor to get them delivered if so.
*/
ENTRY(xen_restore_fl_direct)
FRAME_BEGIN
#ifdef CONFIG_X86_64
testw $X86_EFLAGS_IF, %di
#else
testb $X86_EFLAGS_IF>>8, %ah
#endif
setz PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask
/*
* Preempt here doesn't matter because that will deal with any
* pending interrupts. The pending check may end up being run
* on the wrong CPU, but that doesn't hurt.
*/
/* check for unmasked and pending */
cmpw $0x0001, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_pending
jnz 1f
call check_events
1:
FRAME_END
ret
ENDPROC(xen_restore_fl_direct)
/*
* Force an event check by making a hypercall, but preserve regs
* before making the call.
*/
ENTRY(check_events)
FRAME_BEGIN
#ifdef CONFIG_X86_32
push %eax
push %ecx
push %edx
call xen_force_evtchn_callback
pop %edx
pop %ecx
pop %eax
#else
push %rax
push %rcx
push %rdx
push %rsi
push %rdi
push %r8
push %r9
push %r10
push %r11
call xen_force_evtchn_callback
pop %r11
pop %r10
pop %r9
pop %r8
pop %rdi
pop %rsi
pop %rdx
pop %rcx
pop %rax
#endif
FRAME_END
ret
ENDPROC(check_events)