From 5b10a0e84b4ebe02a7018846e882caa112b4ffc6 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Tue, 22 Sep 2015 11:24:20 -0700 Subject: [PATCH] MIPS: Always use r4k_wait_irqoff for MIPSr6 Prior to release 6 of the MIPS architecture it has been implementation dependent whether masked interrupts cause a wait instruction to return, so the kernel has effectively had to maintain a whitelist of cores upon which it is safe to use the r4k_wait_irqoff cpu_wait implementation. With MIPSr6 this is no longer implementation dependent and r4k_wait_irqoff can always be used. Remove the existing I6400 case which will no longer ever be hit, and was incorrect anyway since I6400 & r6 in general doesn't have the WII bit. Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Cc: Leonid Yegoshin Cc: linux-kernel@vger.kernel.org Cc: James Hogan Cc: Markos Chandras Patchwork: https://patchwork.linux-mips.org/patch/11210/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/idle.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/mips/kernel/idle.c b/arch/mips/kernel/idle.c index ab1478d..3e2b0b6 100644 --- a/arch/mips/kernel/idle.c +++ b/arch/mips/kernel/idle.c @@ -134,6 +134,16 @@ void __init check_wait(void) return; } + /* + * MIPSr6 specifies that masked interrupts should unblock an executing + * wait instruction, and thus that it is safe for us to use + * r4k_wait_irqoff. Yippee! + */ + if (cpu_has_mips_r6) { + cpu_wait = r4k_wait_irqoff; + return; + } + switch (current_cpu_type()) { case CPU_R3081: case CPU_R3081E: @@ -196,7 +206,6 @@ void __init check_wait(void) case CPU_INTERAPTIV: case CPU_M5150: case CPU_QEMU_GENERIC: - case CPU_I6400: cpu_wait = r4k_wait; if (read_c0_config7() & MIPS_CONF7_WII) cpu_wait = r4k_wait_irqoff; -- 2.7.4