Re: [PATCH] MIPS: mm: tlbex: Replace cpu_has_mips_r2_exec_hazard with cpu_has_mips_r2_r6

[Ralf Baechle <ralf@linux-mips.org>]

On Fri, Mar 13, 2015 at 09:18:08AM +0000, Markos Chandras wrote:

> Commit 77f3ee59ee7cf ("MIPS: mm: tlbex: Use cpu_has_mips_r2_exec_hazard
> for the EHB instruction") replaced cpu_has_mips_r2 with
> cpu_has_mips_r2_exec_hazard to indicate whether the ISA has the EHB
> instruction. However, the meaning of the cpu_has_mips_r2_exec_hazard
> is different. It was meant to be used as an indication on whether the
> running processor needs to run the EHB instruction instead of checking
> whether the EHB is available on the ISA. This broke processors that do
> not define cpu_has_mips_r2_exec_hazard. We fix this by replacing the
> said macro with cpu_has_mips_r2_r6 which covers R2 and R6 processors.
> 
> Fixes: 77f3ee59ee7cf ("MIPS: mm: tlbex: Use cpu_has_mips_r2_exec_hazard for the EHB instruction")
> Cc: David Daney <david.daney@cavium.com>
> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>

Either of this David's revert or this patch applied will leave
cpu_has_mips_r2_exec_hazard unused which at a glance doesn't seem to
be right and defeats David's old patches 9e290a19 / 41f0e4d0 from working.

cpu_has_mips_r2_exec_hazard was made unused by 625c0a21 which I think
should be reverted and cpu_has_mips_r2_exec_hazard be defined to be something
like

#define cpu_has_mips_r2_exec_hazard					\
({									\
	int __res;							\
									\
	switch (current_cpu_type()) {					\
	case CPU_M14KC:							\
	case CPU74K:							\
	case CPU_CAVIUM_OCTEON:						\
	case CPU_CAVIUM_OCTEON_PLUS:					\
        case CPU_CAVIUM_OCTEON2:					\
	case CPU_CAVIUM_OCTEON3:					\
		__res = 0;						\
		break;							\
									\
	default:							\
		__res = 1;						\
	}								\
									\
	__res;								\
})

?

  Ralf