HTW needs to stop and start again whenever the EntryHI register
changes otherwise an inflight HTW operation might use the new
EntryHI register for updating an old entry and that could lead
to crashes or even a machine check exception. We fix this by
ensuring the HTW has stop whenever the EntryHI register is about
to change
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: <stable@vger.kernel.org> # v3.17+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8511/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
local_irq_save(flags);
+ htw_stop();
pid = read_c0_entryhi() & ASID_MASK;
address &= (PAGE_MASK << 1);
write_c0_entryhi(address | pid);
tlb_write_indexed();
}
tlbw_use_hazard();
+ htw_start();
flush_itlb_vm(vma);
local_irq_restore(flags);
}
local_irq_save(flags);
/* Save old context and create impossible VPN2 value */
+ htw_stop();
old_ctx = read_c0_entryhi();
old_pagemask = read_c0_pagemask();
wired = read_c0_wired();
write_c0_entryhi(old_ctx);
write_c0_pagemask(old_pagemask);
+ htw_start();
out:
local_irq_restore(flags);
return ret;