port-sparc/47771: possible fatal typo in sparc sbus_bus_addr() function

[Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>]

>Number:         47771
>Category:       port-sparc
>Synopsis:       possible fatal typo in sparc sbus_bus_addr() function
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    port-sparc-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Apr 27 04:05:00 +0000 2013
>Originator:     Izumi Tsutsui
>Release:        NetBSD 6.0
>Organization:
>Environment:
System: NetBSD/sparc 6.0 GENERIC
Architecture: sparc
Machine: sparc
>Description:
It looks there is (a bit fatal) type in sbus_bus_addr() function,
which is used for framebuffer's mmap() functions.

sys/arch/sparc/dev/sbus.c has the following code:
http://nxr.netbsd.org/xref/src/sys/arch/sparc/dev/sbus.c?r=1.78#507

    507 bus_addr_t
    508 sbus_bus_addr(bus_space_tag_t t, u_int btype, u_int offset)
    509 {
    510 
    511         /* XXX: sbus_bus_addr should be g/c'ed */
    512         return (BUS_ADDR(btype, offset));
    513 }

The caller of this function in sys/dev/sbus/cgsix_sbus.c is:
http://nxr.netbsd.org/xref/src/sys/dev/sbus/cgsix_sbus.c?r=1.30#98

     98         /* Remember cookies for cgsix_mmap() */
     99         sc->sc_bustag = sa->sa_bustag;
    100         sc->sc_paddr = sbus_bus_addr(sa->sa_bustag, sa->sa_slot, 
sa->sa_offset);

So sbus_bus_addr() takes a slot number in the 2nd arg
and offset in the 3rd arg.

This sc->sc_paddr is used to mmap(2) framebuffers in MI cgsix driver:
http://nxr.netbsd.org/xref/src/sys/dev/sun/cgsix.c?r=1.60#1100

   1114                         return (bus_space_mmap(sc->sc_bustag,
   1115                                 sc->sc_paddr, u+mo->mo_physoff,
   1116                                 prot, BUS_SPACE_MAP_LINEAR));

On the other hand, the definition of BUS_ADDR() is:
http://nxr.netbsd.org/xref/src/sys/arch/sparc/include/bus_defs.h?r=1.1#79

     79 #define BUS_ADDR(io, pa)        \
     80         ((((uint64_t)(uint32_t)(io))<<32) | (uint32_t)(pa))

so there is no slot or offset in it.

The definition of SBUS_ADDR() is:
http://nxr.netbsd.org/xref/src/sys/arch/sparc/dev/sbusreg.h?r=1.6#54

     54 #define SBUS_ADDR(slot, off)    (SBUS_BASE + ((slot) << 25) + (off))

so it looks BUS_ADDR() in sbus_bus_addr() is a typo of SBUS_ADDR().

>How-To-Repeat:
Code inspection.

>Fix:
See above, but needs more confirmation by sparc guru.
I'm not sure how sparc Xservers works, but applications
which directly access wsfb via wsdisplay (ttyE0)
don't work on sparc.