From 0db34215c7e0ef618e7b29fbf271194ca5434f8e Mon Sep 17 00:00:00 2001 From: "Kevin D. Kissell" Date: Thu, 12 Jul 2007 16:21:08 +0100 Subject: [MIPS] SMTC: Interrupt mask backstop hack To support multiple TC microthreads acting as "CPUs" within a VPE, VPE-wide interrupt mask bits must be specially manipulated during interrupt handling. To support legacy drivers and interrupt controller management code, SMTC has a "backstop" to track and if necessary restore the interrupt mask. This has some performance impact on interrupt service overhead. Disable it only if you know what you are doing. Signed-off-by: Ralf Baechle --- arch/mips/kernel/entry.S | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/mips/kernel/entry.S') diff --git a/arch/mips/kernel/entry.S b/arch/mips/kernel/entry.S index 686249c5c328..e29598ae939d 100644 --- a/arch/mips/kernel/entry.S +++ b/arch/mips/kernel/entry.S @@ -84,6 +84,7 @@ FEXPORT(restore_all) # restore full frame LONG_S sp, TI_REGS($28) jal deferred_smtc_ipi LONG_S s0, TI_REGS($28) +#ifdef CONFIG_MIPS_MT_SMTC_IM_BACKSTOP /* Re-arm any temporarily masked interrupts not explicitly "acked" */ mfc0 v0, CP0_TCSTATUS ori v1, v0, TCSTATUS_IXMT @@ -110,6 +111,7 @@ FEXPORT(restore_all) # restore full frame _ehb xor t0, t0, t3 mtc0 t0, CP0_TCCONTEXT +#endif /* CONFIG_MIPS_MT_SMTC_IM_BACKSTOP */ #endif /* CONFIG_MIPS_MT_SMTC */ .set noat RESTORE_TEMP -- cgit