[PATCH] [2.4] show TCE statistics in /proc/ppc64

[linas at austin.ibm.com]

The attached patch should apply cleanly against the current
ameslab-2.4 tree.  It provides TCE usage statistics in /proc
that might be useful to anyone interested in DMA performance
or is debugging DMA usage in device drivers.

I don't have BK access so I can't bk push anything at this time:
Paul, if this patch looks good, can you apply & etc. as needed?

The TCE usage stats are in the /proc/ppc64/tce directory.
Get stats for all PCI devices by 'cat /proc/ppc64/tce/stats'.
One can also get more detailed per-device stats by performing an
'echo "show bb:dd" > /proc/ppc64/tce/stats'
where bb os the hex bus number, dd is the hex device number
(cat /proc/ppc64/pci to figure these out).  One can then
'cat /proc/ppc64/tce/detail-bb:dd' to see the detailed stats.

Here's a sample of the 'detail' output:

device 21:01
Fri Nov 21 14:04:07 PST 2003
total_use_cnt=92042 alloc_cnt=1267 max_alloc_cnt=1267
        Level   use_cnt split   merge   alloc   maxaloc actual  stale   entries
        0       29552   0       0       59      114     59      1       32768
        1       1988    60      7       662     675     3       0       16384
        2       3882    35      5       11      25      11      0       8192
        3       7147    31      5       30      44      30      0       4096
        4       12405   44      12      45      69      45      0       2048
        5       28815   71      26      285     285     285     0       1024
        6       8253    336     171     175     175     175     0       512
        7       0       633     463     0       1       0       0       256
        8       0       314     229     0       1       0       0       128
        9       0       153     110     0       1       0       0       64

[dump of TCE bitmaps cut out]

--linas

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