Commits
Naveen N. Rao committed 5d6a03ebc88
powerpc/hw_breakpoint: Only disable hw breakpoint if cpu supports it
We get the below warning if we try to use kexec on P9:
kexec_core: Starting new kernel
WARNING: CPU: 0 PID: 1223 at arch/powerpc/kernel/process.c:826 __set_breakpoint+0xb4/0x140
[snip]
NIP __set_breakpoint+0xb4/0x140
LR kexec_prepare_cpus_wait+0x58/0x150
Call Trace:
0xc0000000ee70fb20 (unreliable)
0xc0000000ee70fb20
default_machine_kexec+0x234/0x2c0
machine_kexec+0x84/0x90
kernel_kexec+0xd8/0xe0
SyS_reboot+0x214/0x2c0
system_call+0x58/0x6c
This happens since we are trying to clear hw breakpoint on POWER9,
though we don't have CPU_FTR_DAWR enabled. Guard __set_breakpoint()
within hw_breakpoint_disable() with ppc_breakpoint_available() to
address this.
Fixes: 9654153158d3 ("powerpc: Disable DAWR in the base POWER9 CPU features")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>