7.0 broken on e4500

[Kris Kennaway]

I get this early during boot with a CVS kernel (updated from last December):

 > FreeBSD/SMP: Multiprocessor System Detected: 10 CPUs
 > panic: tsb_tte_enter: replacing valid kernel mapping
 > cpuid = 0
 > KDB: enter: panic
 > [thread pid 0 tid 0 ]
 > Stopped at      kdb_enter+0x68: ta              %xcc, 1
 > db> wh
 > Tracing pid 0 tid 0 td 0xc0744f80
 > panic() at panic+0x204
 > tsb_tte_enter() at tsb_tte_enter+0xdc
 > pmap_enter_locked() at pmap_enter_locked+0x2d0
 > pmap_enter() at pmap_enter+0x64
 > kmem_malloc() at kmem_malloc+0x6e0
 > page_alloc() at page_alloc+0x28
 > uma_large_malloc() at uma_large_malloc+0x44
 > malloc() at malloc+0x1b0
 > sf_buf_init() at sf_buf_init+0xf8
 > mi_startup() at mi_startup+0x18c
 > btext() at btext+0x34

Kris