xen64: add 64-bit assembler

Split xen-asm into 32- and 64-bit files, and implement the 64-bit
variants.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 142 insertions, 1 deletions

diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile
index 2ba2d1649131..59c1e539aed2 100644
--- a/arch/x86/xen/Makefile
+++ b/arch/x86/xen/Makefile
@@ -1,4 +1,4 @@
 obj-y           := enlighten.o setup.o multicalls.o mmu.o \
-                        time.o xen-asm.o grant-table.o suspend.o
+                        time.o xen-asm_$(BITS).o grant-table.o suspend.o
 
 obj-$(CONFIG_SMP)       += smp.o
diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm_32.S
index 2497a30f41de..2497a30f41de 100644
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm_32.S
diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
new file mode 100644
index 000000000000..4ec10827370b
--- /dev/null
+++ b/arch/x86/xen/xen-asm_64.S
@@ -0,0 +1,141 @@
+/*
+        Asm versions of Xen pv-ops, suitable for either direct use or inlining.
+        The inline versions are the same as the direct-use versions, with the
+        pre- and post-amble chopped off.
+
+        This code is encoded for size rather than absolute efficiency,
+        with a view to being able to inline as much as possible.
+
+        We only bother with direct forms (ie, vcpu in pda) of the operations
+        here; the indirect forms are better handled in C, since they're
+        generally too large to inline anyway.
+ */
+
+#include <linux/linkage.h>
+
+#include <asm/asm-offsets.h>
+#include <asm/processor-flags.h>
+
+#include <xen/interface/xen.h>
+
+#define RELOC(x, v)     .globl x##_reloc; x##_reloc=v
+#define ENDPATCH(x)     .globl x##_end; x##_end=.
+
+/* Pseudo-flag used for virtual NMI, which we don't implement yet */
+#define XEN_EFLAGS_NMI  0x80000000
+
+#if 0
+#include <asm/percpu.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)
+        /* 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
+
+2:      call check_events
+1:
+ENDPATCH(xen_irq_enable_direct)
+        ret
+        ENDPROC(xen_irq_enable_direct)
+        RELOC(xen_irq_enable_direct, 2b+1)
+
+/*
+        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)
+ENDPATCH(xen_irq_disable_direct)
+        ret
+        ENDPROC(xen_irq_disable_direct)
+        RELOC(xen_irq_disable_direct, 0)
+
+/*
+        (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
+ENDPATCH(xen_save_fl_direct)
+        ret
+        ENDPROC(xen_save_fl_direct)
+        RELOC(xen_save_fl_direct, 0)
+
+/*
+        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)
+        testb $X86_EFLAGS_IF>>8, %ah
+        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)
+        jz 1f
+2:      call check_events
+1:
+ENDPATCH(xen_restore_fl_direct)
+        ret
+        ENDPROC(xen_restore_fl_direct)
+        RELOC(xen_restore_fl_direct, 2b+1)
+
+
+/*
+        Force an event check by making a hypercall,
+        but preserve regs before making the call.
+ */
+check_events:
+        push %rax
+        push %rcx
+        push %rdx
+        push %rsi
+        push %rdi
+        push %r8
+        push %r9
+        push %r10
+        push %r11
+        call force_evtchn_callback
+        pop %r11
+        pop %r10
+        pop %r9
+        pop %r8
+        pop %rdi
+        pop %rsi
+        pop %rdx
+        pop %rcx
+        pop %rax
+        ret
+#endif
+
+ENTRY(xen_iret)
+        pushq $0
+        jmp hypercall_page + __HYPERVISOR_iret * 32
+
+ENTRY(xen_sysexit)
+        ud2a