MIPS: MT: Remove SMTC support

Nobody is maintaining SMTC anymore and there also seems to be no userbase.
Which is a pity - the SMTC technology primarily developed by Kevin D.
Kissell <kevink@paralogos.com> is an ingenious demonstration for the MT
ASE's power and elegance.

Based on Markos Chandras <Markos.Chandras@imgtec.com> patch
https://patchwork.linux-mips.org/patch/6719/ which while very similar did
no longer apply cleanly when I tried to merge it plus some additional
post-SMTC cleanup - SMTC was a feature as tricky to remove as it was to
merge once upon a time.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 0 insertions, 96 deletions

diff --git a/arch/mips/include/asm/irq.h b/arch/mips/include/asm/irq.h
index 7bc2cdb35057..ae1f7b24dd1a 100644
--- a/arch/mips/include/asm/irq.h
+++ b/arch/mips/include/asm/irq.h
@@ -26,104 +26,8 @@ static inline int irq_canonicalize(int irq)
 #define irq_canonicalize(irq) (irq)	/* Sane hardware, sane code ... */
 #endif
 
-#ifdef CONFIG_MIPS_MT_SMTC
-
-struct irqaction;
-
-extern unsigned long irq_hwmask[];
-extern int setup_irq_smtc(unsigned int irq, struct irqaction * new,
-			  unsigned long hwmask);
-
-static inline void smtc_im_ack_irq(unsigned int irq)
-{
-	if (irq_hwmask[irq] & ST0_IM)
-		set_c0_status(irq_hwmask[irq] & ST0_IM);
-}
-
-#else
-
-static inline void smtc_im_ack_irq(unsigned int irq)
-{
-}
-
-#endif /* CONFIG_MIPS_MT_SMTC */
-
-#ifdef CONFIG_MIPS_MT_SMTC_IRQAFF
-#include <linux/cpumask.h>
-
-extern int plat_set_irq_affinity(struct irq_data *d,
-				 const struct cpumask *affinity, bool force);
-extern void smtc_forward_irq(struct irq_data *d);
-
-/*
- * IRQ affinity hook invoked at the beginning of interrupt dispatch
- * if option is enabled.
- *
- * Up through Linux 2.6.22 (at least) cpumask operations are very
- * inefficient on MIPS.	 Initial prototypes of SMTC IRQ affinity
- * used a "fast path" per-IRQ-descriptor cache of affinity information
- * to reduce latency.  As there is a project afoot to optimize the
- * cpumask implementations, this version is optimistically assuming
- * that cpumask.h macro overhead is reasonable during interrupt dispatch.
- */
-static inline int handle_on_other_cpu(unsigned int irq)
-{
-	struct irq_data *d = irq_get_irq_data(irq);
-
-	if (cpumask_test_cpu(smp_processor_id(), d->affinity))
-		return 0;
-	smtc_forward_irq(d);
-	return 1;
-}
-
-#else /* Not doing SMTC affinity */
-
-static inline int handle_on_other_cpu(unsigned int irq) { return 0; }
-
-#endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */
-
-#ifdef CONFIG_MIPS_MT_SMTC_IM_BACKSTOP
-
-static inline void smtc_im_backstop(unsigned int irq)
-{
-	if (irq_hwmask[irq] & 0x0000ff00)
-		write_c0_tccontext(read_c0_tccontext() &
-				   ~(irq_hwmask[irq] & 0x0000ff00));
-}
-
-/*
- * Clear interrupt mask handling "backstop" if irq_hwmask
- * entry so indicates. This implies that the ack() or end()
- * functions will take over re-enabling the low-level mask.
- * Otherwise it will be done on return from exception.
- */
-static inline int smtc_handle_on_other_cpu(unsigned int irq)
-{
-	int ret = handle_on_other_cpu(irq);
-
-	if (!ret)
-		smtc_im_backstop(irq);
-	return ret;
-}
-
-#else
-
-static inline void smtc_im_backstop(unsigned int irq) { }
-static inline int smtc_handle_on_other_cpu(unsigned int irq)
-{
-	return handle_on_other_cpu(irq);
-}
-
-#endif
-
 extern void do_IRQ(unsigned int irq);
 
-#ifdef CONFIG_MIPS_MT_SMTC_IRQAFF
-
-extern void do_IRQ_no_affinity(unsigned int irq);
-
-#endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */
-
 extern void arch_init_irq(void);
 extern void spurious_interrupt(void);