c6x: remove architecture

The c6x architecture was added to the kernel in 2011 at a time when
running Linux on DSPs was widely seen as the logical evolution.
It appears the trend has gone back to running Linux on Arm based SoCs
with DSP, using a better supported software ecosystem, and having better
real-time behavior for the DSP code. An example of this is TI's own
Keystone2 platform.

The upstream kernel port appears to no longer have any users. Mark
Salter remained avaialable to review patches, but mentioned that
he no longer has access to working hardware himself. Without any
users, it's best to just remove the code completely to reduce the
work for cross-architecture code changes.

Many thanks to Mark for maintaining the code for the past ten years.

Link: https://lore.kernel.org/lkml/41dc7795afda9f776d8cd0d3075f776cf586e97c.camel@redhat.com/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 0 insertions, 127 deletions

diff --git a/arch/c6x/kernel/irq.c b/arch/c6x/kernel/irq.c
deleted file mode 100644
index e4c53d185b62..000000000000
--- a/arch/c6x/kernel/irq.c
+++ /dev/null
@@ -1,127 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- *  Copyright (C) 2011-2012 Texas Instruments Incorporated
- *
- *  This borrows heavily from powerpc version, which is:
- *
- *  Derived from arch/i386/kernel/irq.c
- *    Copyright (C) 1992 Linus Torvalds
- *  Adapted from arch/i386 by Gary Thomas
- *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
- *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
- *    Copyright (C) 1996-2001 Cort Dougan
- *  Adapted for Power Macintosh by Paul Mackerras
- *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
- */
-#include <linux/slab.h>
-#include <linux/seq_file.h>
-#include <linux/radix-tree.h>
-#include <linux/module.h>
-#include <linux/of.h>
-#include <linux/of_irq.h>
-#include <linux/interrupt.h>
-#include <linux/kernel_stat.h>
-
-#include <asm/megamod-pic.h>
-#include <asm/special_insns.h>
-
-unsigned long irq_err_count;
-
-static DEFINE_RAW_SPINLOCK(core_irq_lock);
-
-static void mask_core_irq(struct irq_data *data)
-{
-	unsigned int prio = data->hwirq;
-
-	raw_spin_lock(&core_irq_lock);
-	and_creg(IER, ~(1 << prio));
-	raw_spin_unlock(&core_irq_lock);
-}
-
-static void unmask_core_irq(struct irq_data *data)
-{
-	unsigned int prio = data->hwirq;
-
-	raw_spin_lock(&core_irq_lock);
-	or_creg(IER, 1 << prio);
-	raw_spin_unlock(&core_irq_lock);
-}
-
-static struct irq_chip core_chip = {
-	.name		= "core",
-	.irq_mask	= mask_core_irq,
-	.irq_unmask	= unmask_core_irq,
-};
-
-static int prio_to_virq[NR_PRIORITY_IRQS];
-
-asmlinkage void c6x_do_IRQ(unsigned int prio, struct pt_regs *regs)
-{
-	struct pt_regs *old_regs = set_irq_regs(regs);
-
-	irq_enter();
-
-	generic_handle_irq(prio_to_virq[prio]);
-
-	irq_exit();
-
-	set_irq_regs(old_regs);
-}
-
-static struct irq_domain *core_domain;
-
-static int core_domain_map(struct irq_domain *h, unsigned int virq,
-			   irq_hw_number_t hw)
-{
-	if (hw < 4 || hw >= NR_PRIORITY_IRQS)
-		return -EINVAL;
-
-	prio_to_virq[hw] = virq;
-
-	irq_set_status_flags(virq, IRQ_LEVEL);
-	irq_set_chip_and_handler(virq, &core_chip, handle_level_irq);
-	return 0;
-}
-
-static const struct irq_domain_ops core_domain_ops = {
-	.map = core_domain_map,
-	.xlate = irq_domain_xlate_onecell,
-};
-
-void __init init_IRQ(void)
-{
-	struct device_node *np;
-
-	/* Mask all priority IRQs */
-	and_creg(IER, ~0xfff0);
-
-	np = of_find_compatible_node(NULL, NULL, "ti,c64x+core-pic");
-	if (np != NULL) {
-		/* create the core host */
-		core_domain = irq_domain_add_linear(np, NR_PRIORITY_IRQS,
-						    &core_domain_ops, NULL);
-		if (core_domain)
-			irq_set_default_host(core_domain);
-		of_node_put(np);
-	}
-
-	printk(KERN_INFO "Core interrupt controller initialized\n");
-
-	/* now we're ready for other SoC controllers */
-	megamod_pic_init();
-
-	/* Clear all general IRQ flags */
-	set_creg(ICR, 0xfff0);
-}
-
-void ack_bad_irq(int irq)
-{
-	printk(KERN_ERR "IRQ: spurious interrupt %d\n", irq);
-	irq_err_count++;
-}
-
-int arch_show_interrupts(struct seq_file *p, int prec)
-{
-	seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
-	return 0;
-}