mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-30 10:56:44 +07:00
72aff53f1f
The sibling cpu bringup is extremely fragile. We can only perform the most basic calls until we take over the trap table from the firmware/hypervisor on the new cpu. This means no accesses to %g4, %g5, %g6 since those can't be TLB translated without our trap handlers. In order to achieve this: 1) Change sun4v_init_mondo_queues() so that it can operate in several modes. It can allocate the queues, or install them in the current processor, or both. The boot cpu does both in it's call early on. Later, the boot cpu allocates the sibling cpu queue, starts the sibling cpu, then the sibling cpu loads them in. 2) init_cur_cpu_trap() is changed to take the current_thread_info() as an argument instead of reading %g6 directly on the current cpu. 3) Create a trampoline stack for the sibling cpus. We do our basic kernel calls using this stack, which is locked into the kernel image, then go to our proper thread stack after taking over the trap table. 4) While we are in this delicate startup state, we put 0xdeadbeef into %g4/%g5/%g6 in order to catch accidental accesses. 5) On the final prom_set_trap_table*() call, we put &init_thread_union into %g6. This is a hack to make prom_world(0) work. All that wants to do is restore the %asi register using get_thread_current_ds(). Longer term we should just do the OBP calls to set the trap table by hand just like we do for everything else. This would avoid that silly prom_world(0) issue, then we can remove the init_thread_union hack. Signed-off-by: David S. Miller <davem@davemloft.net> |
||
|---|---|---|
| .. | ||
| boot | ||
| kernel | ||
| lib | ||
| math-emu | ||
| mm | ||
| oprofile | ||
| prom | ||
| solaris | ||
| defconfig | ||
| Kconfig | ||
| Kconfig.debug | ||
| Makefile | ||