[MIPS] SMTC: Interrupt mask backstop hack (0db34215) · Commits · 戴 / test

arch/mips/Kconfig

+13 −0

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		@@ -1404,6 +1404,19 @@ config MIPS_MT_SMTC_INSTANT_REPLAY
		it off), but ensures that IPIs are handled promptly even under
		heavy I/O interrupt load.

		config MIPS_MT_SMTC_IM_BACKSTOP
		bool "Use per-TC register bits as backstop for inhibited IM bits"
		depends on MIPS_MT_SMTC
		default y
		help
		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.

		config MIPS_VPE_LOADER_TOM
		bool "Load VPE program into memory hidden from linux"
		depends on MIPS_VPE_LOADER

+2 −0

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		@@ -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

+2 −0

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		@@ -243,9 +243,11 @@ NESTED(except_vec_vi_handler, 0, sp)
		*/
		mfc0 t1, CP0_STATUS
		and t0, a0, t1
		#ifdef CONFIG_MIPS_MT_SMTC_IM_BACKSTOP
		mfc0 t2, CP0_TCCONTEXT
		or t0, t0, t2
		mtc0 t0, CP0_TCCONTEXT
		#endif /* CONFIG_MIPS_MT_SMTC_IM_BACKSTOP */
		xor t1, t1, t0
		mtc0 t1, CP0_STATUS
		_ehb

+1 −1

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		@@ -24,7 +24,7 @@ static inline int irq_canonicalize(int irq)
		#define irq_canonicalize(irq) (irq) /* Sane hardware, sane code ... */
		#endif

		#ifdef CONFIG_MIPS_MT_SMTC
		#ifdef CONFIG_MIPS_MT_SMTC_IM_BACKSTOP
		/*
		* Clear interrupt mask handling "backstop" if irq_hwmask
		* entry so indicates. This implies that the ack() or end()