On Tue, Dec 1, 2015 at 2:32 PM, Sinclair Yeh <syeh@xxxxxxxxxx> wrote:
> Hi,
>
> On Tue, Dec 01, 2015 at 02:24:14PM -0800, Dmitry Torokhov wrote:
>> On Tue, Dec 01, 2015 at 02:18:49PM -0800, Sinclair Yeh wrote:
>> > v2:
>> > Instead of replacing existing VMMOUSE defines, only modify enough
>> > to use the new VMW_PORT define.
>> >
>> > v3:
>> > Use updated VMWARE_PORT() which requires hypervisor magic as an added
>> > parameter
>> >
>> > Signed-off-by: Sinclair Yeh <syeh@xxxxxxxxxx>
>> > Reviewed-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
>> > Reviewed-by: Alok N Kataria <akataria@xxxxxxxxxx>
>> > Cc: pv-drivers@xxxxxxxxxx
>> > Cc: linux-graphics-maintainer@xxxxxxxxxx
>> > Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
>> > Cc: Arnd Bergmann <arnd@xxxxxxxx>
>> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>> > Cc: linux-kernel@xxxxxxxxxxxxxxx
>> > Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
>> > Cc: linux-input@xxxxxxxxxxxxxxx
>> > ---
>> > drivers/input/mouse/vmmouse.c | 22 +++++++---------------
>> > 1 file changed, 7 insertions(+), 15 deletions(-)
>> >
>> > diff --git a/drivers/input/mouse/vmmouse.c b/drivers/input/mouse/vmmouse.c
>> > index e272f06..d34e3e4 100644
>> > --- a/drivers/input/mouse/vmmouse.c
>> > +++ b/drivers/input/mouse/vmmouse.c
>> > @@ -19,6 +19,7 @@
>> > #include <linux/slab.h>
>> > #include <linux/module.h>
>> > #include <asm/hypervisor.h>
>> > +#include <asm/vmware.h>
>> >
>> > #include "psmouse.h"
>> > #include "vmmouse.h"
>> > @@ -84,21 +85,12 @@ struct vmmouse_data {
>> > * implementing the vmmouse protocol. Should never execute on
>> > * bare metal hardware.
>> > */
>> > -#define VMMOUSE_CMD(cmd, in1, out1, out2, out3, out4) \
>> > -({ \
>> > - unsigned long __dummy1, __dummy2; \
>> > - __asm__ __volatile__ ("inl %%dx" : \
>> > - "=a"(out1), \
>> > - "=b"(out2), \
>> > - "=c"(out3), \
>> > - "=d"(out4), \
>> > - "=S"(__dummy1), \
>> > - "=D"(__dummy2) : \
>> > - "a"(VMMOUSE_PROTO_MAGIC), \
>> > - "b"(in1), \
>> > - "c"(VMMOUSE_PROTO_CMD_##cmd), \
>> > - "d"(VMMOUSE_PROTO_PORT) : \
>> > - "memory"); \
>> > +#define VMMOUSE_CMD(cmd, in1, out1, out2, out3, out4) \
>> > +({ \
>> > + unsigned long __dummy1 = 0, __dummy2 = 0; \
>>
>> Why do we need to initialize dummies?
>
> Because for some commands those parameters to VMW_PORT() can be both
> input and outout.
The vmmouse commands do not use them as input though, so it seems we
are simply wasting CPU cycles setting them to 0 just because we are
using the new VMW_PORT here. Why do we need to switch? What is the
benefit of doing this?
Thanks.
--
Dmitry
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