Patches to allow usefdt mode that works on a 2 socket PowerMac3, 6 example too --and makes more work on 2-socket/1-core-each PowerMac11, 2

[Mark Millard]

On 2019-Apr-13, at 11:39, Mark Millard <marklmi at yahoo.com> wrote:

> [My adjustment to fdt_add_subnode_namelen was inept.]
> 
> On 2019-Apr-12, at 16:17, Mark Millard <marklmi at yahoo.com> wrote:
> 
>> On 2019-Apr-12, at 14:20, Dennis Clarke <dclarke a t blastwave.org> wrote:
>> 
>>> On 4/12/19 4:51 PM, Mark Millard wrote:
>>>> On 2019-Apr-12, at 13:13, Dennis Clarke <dclarke at blastwave.org> wrote:
>>>>> On 4/12/19 3:19 PM, Mark Millard via freebsd-ppc wrote:
>>> .
>>> .
>>> .
>>>>> 
>>>>> Would you be so kind as to paste all this into :
>>>>> 
>>>>> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=233863
>>>>> 
>>>>> Really I would like to run some tests and follow up in the bug reports.
>>>> Okay I'll paste them in as attachments. But be warned:
>>> 
>>> Fair warning received loud and clear :-)
>>> 
>>>> The 2 files do not deal with threads being stuck sleeping
>>>> (and, so, the fans going) or other such. The stuck-sleeping
>>>> problem happens for both multi-socket G5's and multi-socket
>>>> G4's. (I do not have access to single-socket multi-core
>>>> powerpc64 or powerpc machines to test.)
>>> 
>>> I have multiple G5 type boxen and will try them out. At least try
>>> to.
>>> 
>>>> So do not expect too much from these patches: They address
>>>> some necessary issues but are not sufficient for everything.
>>>> 
>>> 
>>> Of course. No problem.
>>> 
>>> 
>>>> These patches for the openfirmware->fdt translation are
>>>> closer to being reasonable for FreeBSD official use
>>>> than my highly context-specific stuck-sleeping patches for
>>>> usefdt mode.
>>> 
>>> Well to be frank we know this is for mac g5 hardware and thus having
>>> them working at all in any fashion is better than the current situation.
>>> Apple made a ton of them and they are dirt cheap and available as
>>> opposed to the IBM Power situation which is expensive and just in
>>> datacenters.
>> 
>> 
>> I have added another attachment with patches for having hang-ups
>> at AP startup happen less often. These are in AIM-specific code
>> and so has less of a chance of causing other contexts problems.
>> They are also powerpc64 specific. Again, the patches are
>> investigatory and not in a form for direct check-in to FreeBSD.
>> 
>> This pair of patches narrows the time period over which threads
>> from the stages:
>> 
>>       SI_SUB_KTHREAD_INIT     = 0xe000000,    /* init process*/
>>       SI_SUB_KTHREAD_PAGE     = 0xe400000,    /* pageout daemon*/
>>       SI_SUB_KTHREAD_VM       = 0xe800000,    /* vm daemon*/
>>       SI_SUB_KTHREAD_BUF      = 0xea00000,    /* buffer daemon*/
>>       SI_SUB_KTHREAD_UPDATE   = 0xec00000,    /* update daemon*/
>>       SI_SUB_KTHREAD_IDLE     = 0xee00000,    /* idle procs*/
>> #ifndef EARLY_AP_STARTUP
>>       SI_SUB_SMP              = 0xf000000,    /* start the APs*/
>> #endif 
>> 
>> can conflict with starting an AP via an slb replacement position
>> picked via expressions like mftb()%n_slbs . It does this by 
>> explicitly picking and setting up a slb slot for its use just
>> before starting the AP.
>> 
>> (The AP has to be part way along before it can do its own
>> automatic-random-slb-slot-replacements from what I can tell.)
>> 
>> The patches do not remove the race and still do sometimes fail to
>> prevent getting a hang-up on a AP start. But it greatly decreased
>> the rate of hangups in my testing. (So it is a good source of
>> evidence about the original problem.)
>> 
>> If EARLY_AP_STARTUP was supported and used, the AP startup would
>> not have hang-up problems from mftb()%n_slbs based slb
>> replacements for other threads.
>> 
>> The patches are a hack, rather than a general/complete fix --and
>> I do not expect to see them in FreeBSD. But they do help set up
>> a better context for investigating other things.
> 
> The disabling of blocking duplicate paths in fdt_add_subnode_namelen
> was done incorrectly. I'll replace the attachment after building
> and testing. I think this is the explanation for the PowerMac11,2
> shutdown -r or -p problems.
> 
> The code should have just disabled the return, more like:
> 
>        if (offset >= 0)
> #if 0
> // Some Macintoshes have identical package-to-pathname results for
> // multiple nodes of the same type and unit under the parent node.
> // Avoid blocking this for fdt.
>                return -FDT_ERR_EXISTS;
> #else
>                ;
> #endif
>        else if (offset != -FDT_ERR_NOTFOUND)
>                return offset;
> 
> Instead the messed up change did the "return offset;" and
> so did not do the addition of the node, instead returning
> the pre-existing one to be manipulated.


I've managed to boot the 2-socket/1-core-each G5 PowerMac7,2 in
usefdt mode. I've added another attachment for patching 3 more
files, also shown below:

Index: /usr/src/sys/powerpc/powermac/hrowpic.c
===================================================================
--- /usr/src/sys/powerpc/powermac/hrowpic.c     (revision 345758)
+++ /usr/src/sys/powerpc/powermac/hrowpic.c     (working copy)
@@ -169,7 +169,7 @@
        hrowpic_write_reg(sc, HPIC_ENABLE, HPIC_SECONDARY, 0);
        hrowpic_write_reg(sc, HPIC_CLEAR,  HPIC_SECONDARY, 0xffffffff);
 
-       powerpc_register_pic(dev, ofw_bus_get_node(dev), 64, 0, FALSE);
+       powerpc_register_pic(dev, OF_xref_from_node(ofw_bus_get_node(dev)), 64, 0, FALSE);
        return (0);
 }
 
Index: /usr/src/sys/powerpc/powermac/uninorth.c
===================================================================
--- /usr/src/sys/powerpc/powermac/uninorth.c    (revision 345758)
+++ /usr/src/sys/powerpc/powermac/uninorth.c    (working copy)
@@ -181,7 +181,7 @@
            <= 0)
                panic("Interrupt but no interrupt parent!\n");
 
-       if (OF_searchprop(iparent, "#interrupt-cells", &icells, sizeof(icells))
+       if (OF_searchprop(OF_node_from_xref(iparent), "#interrupt-cells", &icells, sizeof(icells))
            <= 0)
                icells = 1;
 
Index: /usr/src/sys/powerpc/powerpc/openpic.c
===================================================================
--- /usr/src/sys/powerpc/powerpc/openpic.c      (revision 345758)
+++ /usr/src/sys/powerpc/powerpc/openpic.c      (working copy)
@@ -37,6 +37,8 @@
 #include <sys/sched.h>
 #include <sys/smp.h>
 
+#include <dev/ofw/openfirm.h>
+
 #include <machine/bus.h>
 #include <machine/intr_machdep.h>
 #include <machine/md_var.h>
@@ -220,7 +222,7 @@
        for (cpu = 0; cpu < sc->sc_ncpu; cpu++)
                openpic_write(sc, OPENPIC_PCPU_TPR(cpu), 0);
 
-       powerpc_register_pic(dev, node, sc->sc_nirq, 4, FALSE);
+       powerpc_register_pic(dev, OF_xref_from_node(node), sc->sc_nirq, 4, FALSE);
 
        /* If this is not a cascaded PIC, it must be the root PIC */
        if (sc->sc_intr == NULL)


===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)