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>

1 files changed, 0 insertions, 305 deletions

diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
deleted file mode 100644
index 2497a30f41de..000000000000
--- a/arch/x86/xen/xen-asm.S
+++ /dev/null
@@ -1,305 +0,0 @@
-/*
-        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/thread_info.h>
-#include <asm/percpu.h>
-#include <asm/processor-flags.h>
-#include <asm/segment.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
-
-/*
-        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)
-
-/*
-        We can't use sysexit directly, because we're not running in ring0.
-        But we can easily fake it up using iret.  Assuming xen_sysexit
-        is jumped to with a standard stack frame, we can just strip it
-        back to a standard iret frame and use iret.
- */
-ENTRY(xen_sysexit)
-        movl PT_EAX(%esp), %eax                 /* Shouldn't be necessary? */
-        orl $X86_EFLAGS_IF, PT_EFLAGS(%esp)
-        lea PT_EIP(%esp), %esp
-
-        jmp xen_iret
-ENDPROC(xen_sysexit)
-
-/*
-        This is run where a normal iret would be run, with the same stack setup:
-              8: eflags
-              4: cs
-        esp-> 0: eip
-
-        This attempts to make sure that any pending events are dealt
-        with on return to usermode, but there is a small window in
-        which an event can happen just before entering usermode.  If
-        the nested interrupt ends up setting one of the TIF_WORK_MASK
-        pending work flags, they will not be tested again before
-        returning to usermode. This means that a process can end up
-        with pending work, which will be unprocessed until the process
-        enters and leaves the kernel again, which could be an
-        unbounded amount of time.  This means that a pending signal or
-        reschedule event could be indefinitely delayed.
-
-        The fix is to notice a nested interrupt in the critical
-        window, and if one occurs, then fold the nested interrupt into
-        the current interrupt stack frame, and re-process it
-        iteratively rather than recursively.  This means that it will
-        exit via the normal path, and all pending work will be dealt
-        with appropriately.
-
-        Because the nested interrupt handler needs to deal with the
-        current stack state in whatever form its in, we keep things
-        simple by only using a single register which is pushed/popped
-        on the stack.
- */
-ENTRY(xen_iret)
-        /* test eflags for special cases */
-        testl $(X86_EFLAGS_VM | XEN_EFLAGS_NMI), 8(%esp)
-        jnz hyper_iret
-
-        push %eax
-        ESP_OFFSET=4    # bytes pushed onto stack
-
-        /* Store vcpu_info pointer for easy access.  Do it this
-           way to avoid having to reload %fs */
-#ifdef CONFIG_SMP
-        GET_THREAD_INFO(%eax)
-        movl TI_cpu(%eax),%eax
-        movl __per_cpu_offset(,%eax,4),%eax
-        mov per_cpu__xen_vcpu(%eax),%eax
-#else
-        movl per_cpu__xen_vcpu, %eax
-#endif
-
-        /* check IF state we're restoring */
-        testb $X86_EFLAGS_IF>>8, 8+1+ESP_OFFSET(%esp)
-
-        /* Maybe enable events.  Once this happens we could get a
-           recursive event, so the critical region starts immediately
-           afterwards.  However, if that happens we don't end up
-           resuming the code, so we don't have to be worried about
-           being preempted to another CPU. */
-        setz XEN_vcpu_info_mask(%eax)
-xen_iret_start_crit:
-
-        /* check for unmasked and pending */
-        cmpw $0x0001, XEN_vcpu_info_pending(%eax)
-
-        /* If there's something pending, mask events again so we
-           can jump back into xen_hypervisor_callback */
-        sete XEN_vcpu_info_mask(%eax)
-
-        popl %eax
-
-        /* From this point on the registers are restored and the stack
-           updated, so we don't need to worry about it if we're preempted */
-iret_restore_end:
-
-        /* Jump to hypervisor_callback after fixing up the stack.
-           Events are masked, so jumping out of the critical
-           region is OK. */
-        je xen_hypervisor_callback
-
-1:      iret
-xen_iret_end_crit:
-.section __ex_table,"a"
-        .align 4
-        .long 1b,iret_exc
-.previous
-
-hyper_iret:
-        /* put this out of line since its very rarely used */
-        jmp hypercall_page + __HYPERVISOR_iret * 32
-
-        .globl xen_iret_start_crit, xen_iret_end_crit
-
-/*
-   This is called by xen_hypervisor_callback in entry.S when it sees
-   that the EIP at the time of interrupt was between xen_iret_start_crit
-   and xen_iret_end_crit.  We're passed the EIP in %eax so we can do
-   a more refined determination of what to do.
-
-   The stack format at this point is:
-        ----------------
-         ss             : (ss/esp may be present if we came from usermode)
-         esp            :
-         eflags         }  outer exception info
-         cs             }
-         eip            }
-        ---------------- <- edi (copy dest)
-         eax            :  outer eax if it hasn't been restored
-        ----------------
-         eflags         }  nested exception info
-         cs             }   (no ss/esp because we're nested
-         eip            }    from the same ring)
-         orig_eax       }<- esi (copy src)
-         - - - - - - - -
-         fs             }
-         es             }
-         ds             }  SAVE_ALL state
-         eax            }
-          :             :
-         ebx            }<- esp
-        ----------------
-
-   In order to deliver the nested exception properly, we need to shift
-   everything from the return addr up to the error code so it
-   sits just under the outer exception info.  This means that when we
-   handle the exception, we do it in the context of the outer exception
-   rather than starting a new one.
-
-   The only caveat is that if the outer eax hasn't been
-   restored yet (ie, it's still on stack), we need to insert
-   its value into the SAVE_ALL state before going on, since
-   it's usermode state which we eventually need to restore.
- */
-ENTRY(xen_iret_crit_fixup)
-        /*
-           Paranoia: Make sure we're really coming from kernel space.
-           One could imagine a case where userspace jumps into the
-           critical range address, but just before the CPU delivers a GP,
-           it decides to deliver an interrupt instead.  Unlikely?
-           Definitely.  Easy to avoid?  Yes.  The Intel documents
-           explicitly say that the reported EIP for a bad jump is the
-           jump instruction itself, not the destination, but some virtual
-           environments get this wrong.
-         */
-        movl PT_CS(%esp), %ecx
-        andl $SEGMENT_RPL_MASK, %ecx
-        cmpl $USER_RPL, %ecx
-        je 2f
-
-        lea PT_ORIG_EAX(%esp), %esi
-        lea PT_EFLAGS(%esp), %edi
-
-        /* If eip is before iret_restore_end then stack
-           hasn't been restored yet. */
-        cmp $iret_restore_end, %eax
-        jae 1f
-
-        movl 0+4(%edi),%eax             /* copy EAX (just above top of frame) */
-        movl %eax, PT_EAX(%esp)
-
-        lea ESP_OFFSET(%edi),%edi       /* move dest up over saved regs */
-
-        /* set up the copy */
-1:      std
-        mov $PT_EIP / 4, %ecx           /* saved regs up to orig_eax */
-        rep movsl
-        cld
-
-        lea 4(%edi),%esp                /* point esp to new frame */
-2:      jmp xen_do_upcall
-
-
-/*
-        Force an event check by making a hypercall,
-        but preserve regs before making the call.
- */
-check_events:
-        push %eax
-        push %ecx
-        push %edx
-        call force_evtchn_callback
-        pop %edx
-        pop %ecx
-        pop %eax
-        ret