forked from Minki/linux
b389889535
The initial TLB mapping for the kernel boot didn't set the memory coherent attribute, MAS2[M], in SMP mode. If this code supported booting a secondary processor, which it doesn't yet, but if it did, then when a secondary processor boots, it would probably signal the primary processor by setting a variable called something like __secondary_hold_acknowledge. However, due to the lack of the M bit, the primary processor would not snoop the transaction (even if a transaction were broadcast). If primary CPU's L1 D-cache had a copy, it would not be flushed and the CPU would never see the ack. Which would have resulted in the primary CPU spinning for a long time, perhaps a full second before it gives up, while it would have waited for the ack from the secondary CPU that it wouldn't have been able to see because of the stale cache. The value of MAS2 for the boot page TLB1 entry is a compile time constant, so there is no need to calculate it in powerpc assembly language. Also, from the MPC8572 manual section 6.12.5.3, "Bits that represent offsets within a page are ignored and should be cleared." Existing code didn't clear them, this code does. The same when the page of KERNELBASE is found; we don't need to use asm to mask the lower 12 bits off. In the code that computes the address to rfi from, don't hard code the offset to 24 bytes, but have the assembler figure that out for us. Signed-off-by: Trent Piepho <tpiepho@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org> |
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| .. | ||
| boot | ||
| configs | ||
| include/asm | ||
| kernel | ||
| kvm | ||
| lib | ||
| math-emu | ||
| mm | ||
| oprofile | ||
| platforms | ||
| sysdev | ||
| xmon | ||
| Kconfig | ||
| Kconfig.debug | ||
| Makefile | ||