Paul Mackerras 8117ac6a6c powerpc/powernv: Switch off MMU before entering nap/sleep/rvwinkle mode ... Currently, when going idle, we set the flag indicating that we are in nap mode (paca->kvm_hstate.hwthread_state) and then execute the nap (or sleep or rvwinkle) instruction, all with the MMU on. This is bad for two reasons: (a) the architecture specifies that those instructions must be executed with the MMU off, and in fact with only the SF, HV, ME and possibly RI bits set, and (b) this introduces a race, because as soon as we set the flag, another thread can switch the MMU to a guest context. If the race is lost, this thread will typically start looping on relocation-on ISIs at 0xc...4400. This fixes it by setting the MSR as required by the architecture before setting the flag or executing the nap/sleep/rvwinkle instruction. Cc: stable@vger.kernel.org [ shreyas@linux.vnet.ibm.com: Edited to handle LE ] Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>		2014-12-15 10:46:32 +11:00
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asm	powerpc/powernv: Switch off MMU before entering nap/sleep/rvwinkle mode	2014-12-15 10:46:32 +11:00
uapi/asm	powerpc: Wire up sys_bpf() syscall	2014-10-22 14:03:06 +11:00