nds32: Remove the architecture

The nds32 architecture, also known as AndeStar V3, is a custom 32-bit
RISC target designed by Andes Technologies. Support was added to the
kernel in 2016 as the replacement RISC-V based V5 processors were
already announced, and maintained by (current or former) Andes
employees.

As explained by Alan Kao, new customers are now all using RISC-V,
and all known nds32 users are already on longterm stable kernels
provided by Andes, with no development work going into mainline
support any more.

While the port is still in a reasonably good shape, it only gets
worse over time without active maintainers, so it seems best
to remove it before it becomes unusable. As always, if it turns
out that there are mainline users after all, and they volunteer
to maintain the port in the future, the removal can be reverted.

Link: https://lore.kernel.org/linux-mm/YhdWNLUhk+x9RAzU@yamatobi.andestech.com/
Link: https://lore.kernel.org/lkml/20220302065213.82702-1-alankao@andestech.com/
Link: https://www.andestech.com/en/products-solutions/andestar-architecture/
Signed-off-by: Alan Kao <alankao@andestech.com>
[arnd: rewrite changelog to provide more background]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

2 files changed, 0 insertions, 157 deletions

diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index c1f611cbfbf8..c6161b0b0cb6 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -92,7 +92,6 @@ obj-$(CONFIG_IRQ_UNIPHIER_AIDET)	+= irq-uniphier-aidet.o
 obj-$(CONFIG_ARCH_SYNQUACER)		+= irq-sni-exiu.o
 obj-$(CONFIG_MESON_IRQ_GPIO)		+= irq-meson-gpio.o
 obj-$(CONFIG_GOLDFISH_PIC) 		+= irq-goldfish-pic.o
-obj-$(CONFIG_NDS32)			+= irq-ativic32.o
 obj-$(CONFIG_QCOM_PDC)			+= qcom-pdc.o
 obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
 obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
diff --git a/drivers/irqchip/irq-ativic32.c b/drivers/irqchip/irq-ativic32.c
deleted file mode 100644
index 223dd2f97d28..000000000000
--- a/drivers/irqchip/irq-ativic32.c
+++ /dev/null
@@ -1,156 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-// Copyright (C) 2005-2017 Andes Technology Corporation
-
-#include <linux/irq.h>
-#include <linux/of.h>
-#include <linux/of_irq.h>
-#include <linux/of_address.h>
-#include <linux/hardirq.h>
-#include <linux/interrupt.h>
-#include <linux/irqdomain.h>
-#include <linux/irqchip.h>
-#include <nds32_intrinsic.h>
-
-#include <asm/irq_regs.h>
-
-unsigned long wake_mask;
-
-static void ativic32_ack_irq(struct irq_data *data)
-{
-	__nds32__mtsr_dsb(BIT(data->hwirq), NDS32_SR_INT_PEND2);
-}
-
-static void ativic32_mask_irq(struct irq_data *data)
-{
-	unsigned long int_mask2 = __nds32__mfsr(NDS32_SR_INT_MASK2);
-	__nds32__mtsr_dsb(int_mask2 & (~(BIT(data->hwirq))), NDS32_SR_INT_MASK2);
-}
-
-static void ativic32_unmask_irq(struct irq_data *data)
-{
-	unsigned long int_mask2 = __nds32__mfsr(NDS32_SR_INT_MASK2);
-	__nds32__mtsr_dsb(int_mask2 | (BIT(data->hwirq)), NDS32_SR_INT_MASK2);
-}
-
-static int nointc_set_wake(struct irq_data *data, unsigned int on)
-{
-	unsigned long int_mask = __nds32__mfsr(NDS32_SR_INT_MASK);
-	static unsigned long irq_orig_bit;
-	u32 bit = 1 << data->hwirq;
-
-	if (on) {
-		if (int_mask & bit)
-			__assign_bit(data->hwirq, &irq_orig_bit, true);
-		else
-			__assign_bit(data->hwirq, &irq_orig_bit, false);
-
-		__assign_bit(data->hwirq, &int_mask, true);
-		__assign_bit(data->hwirq, &wake_mask, true);
-
-	} else {
-		if (!(irq_orig_bit & bit))
-			__assign_bit(data->hwirq, &int_mask, false);
-
-		__assign_bit(data->hwirq, &wake_mask, false);
-		__assign_bit(data->hwirq, &irq_orig_bit, false);
-	}
-
-	__nds32__mtsr_dsb(int_mask, NDS32_SR_INT_MASK);
-
-	return 0;
-}
-
-static struct irq_chip ativic32_chip = {
-	.name = "ativic32",
-	.irq_ack = ativic32_ack_irq,
-	.irq_mask = ativic32_mask_irq,
-	.irq_unmask = ativic32_unmask_irq,
-	.irq_set_wake = nointc_set_wake,
-};
-
-static unsigned int __initdata nivic_map[6] = { 6, 2, 10, 16, 24, 32 };
-
-static struct irq_domain *root_domain;
-static int ativic32_irq_domain_map(struct irq_domain *id, unsigned int virq,
-				  irq_hw_number_t hw)
-{
-
-	unsigned long int_trigger_type;
-	u32 type;
-	struct irq_data *irq_data;
-	int_trigger_type = __nds32__mfsr(NDS32_SR_INT_TRIGGER);
-	irq_data = irq_get_irq_data(virq);
-	if (!irq_data)
-		return -EINVAL;
-
-	if (int_trigger_type & (BIT(hw))) {
-		irq_set_chip_and_handler(virq, &ativic32_chip, handle_edge_irq);
-		type = IRQ_TYPE_EDGE_RISING;
-	} else {
-		irq_set_chip_and_handler(virq, &ativic32_chip, handle_level_irq);
-		type = IRQ_TYPE_LEVEL_HIGH;
-	}
-
-	irqd_set_trigger_type(irq_data, type);
-	return 0;
-}
-
-static const struct irq_domain_ops ativic32_ops = {
-	.map = ativic32_irq_domain_map,
-	.xlate = irq_domain_xlate_onecell
-};
-
-static irq_hw_number_t get_intr_src(void)
-{
-	return ((__nds32__mfsr(NDS32_SR_ITYPE) & ITYPE_mskVECTOR) >> ITYPE_offVECTOR)
-		- NDS32_VECTOR_offINTERRUPT;
-}
-
-static void ativic32_handle_irq(struct pt_regs *regs)
-{
-	irq_hw_number_t hwirq = get_intr_src();
-	generic_handle_domain_irq(root_domain, hwirq);
-}
-
-/*
- * TODO: convert nds32 to GENERIC_IRQ_MULTI_HANDLER so that this entry logic
- * can live in arch code.
- */
-asmlinkage void asm_do_IRQ(struct pt_regs *regs)
-{
-	struct pt_regs *old_regs;
-
-	irq_enter();
-	old_regs = set_irq_regs(regs);
-	ativic32_handle_irq(regs);
-	set_irq_regs(old_regs);
-	irq_exit();
-}
-
-int __init ativic32_init_irq(struct device_node *node, struct device_node *parent)
-{
-	unsigned long int_vec_base, nivic, nr_ints;
-
-	if (WARN(parent, "non-root ativic32 are not supported"))
-		return -EINVAL;
-
-	int_vec_base = __nds32__mfsr(NDS32_SR_IVB);
-
-	if (((int_vec_base & IVB_mskIVIC_VER) >> IVB_offIVIC_VER) == 0)
-		panic("Unable to use atcivic32 for this cpu.\n");
-
-	nivic = (int_vec_base & IVB_mskNIVIC) >> IVB_offNIVIC;
-	if (nivic >= ARRAY_SIZE(nivic_map))
-		panic("The number of input for ativic32 is not supported.\n");
-
-	nr_ints = nivic_map[nivic];
-
-	root_domain = irq_domain_add_linear(node, nr_ints,
-			&ativic32_ops, NULL);
-
-	if (!root_domain)
-		panic("%s: unable to create IRQ domain\n", node->full_name);
-
-	return 0;
-}
-IRQCHIP_DECLARE(ativic32, "andestech,ativic32", ativic32_init_irq);