VX_STATUS
while((inw(BASE + VX_STATUS) & S_COMMAND_IN_PROGRESS) != 0)
cst=inw(BASE + VX_STATUS);
while (inw(BASE + VX_STATUS) & S_COMMAND_IN_PROGRESS);
#define VX_BUSY_WAIT while (inw(BASE + VX_STATUS) & S_COMMAND_IN_PROGRESS)