From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 20:49:45 +0200
Subject: Adding upstream version 6.1.76.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 arch/mips/sibyte/bcm1480/irq.c | 348 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 348 insertions(+)
 create mode 100644 arch/mips/sibyte/bcm1480/irq.c

(limited to 'arch/mips/sibyte/bcm1480/irq.c')

diff --git a/arch/mips/sibyte/bcm1480/irq.c b/arch/mips/sibyte/bcm1480/irq.c
new file mode 100644
index 000000000..7929bee91
--- /dev/null
+++ b/arch/mips/sibyte/bcm1480/irq.c
@@ -0,0 +1,348 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2000,2001,2002,2003,2004 Broadcom Corporation
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <linux/interrupt.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+#include <linux/mm.h>
+#include <linux/kernel_stat.h>
+
+#include <asm/errno.h>
+#include <asm/irq_regs.h>
+#include <asm/signal.h>
+#include <asm/io.h>
+
+#include <asm/sibyte/bcm1480_regs.h>
+#include <asm/sibyte/bcm1480_int.h>
+#include <asm/sibyte/bcm1480_scd.h>
+
+#include <asm/sibyte/sb1250_uart.h>
+#include <asm/sibyte/sb1250.h>
+
+/*
+ * These are the routines that handle all the low level interrupt stuff.
+ * Actions handled here are: initialization of the interrupt map, requesting of
+ * interrupt lines by handlers, dispatching if interrupts to handlers, probing
+ * for interrupt lines
+ */
+
+#ifdef CONFIG_PCI
+extern unsigned long ht_eoi_space;
+#endif
+
+/* Store the CPU id (not the logical number) */
+int bcm1480_irq_owner[BCM1480_NR_IRQS];
+
+static DEFINE_RAW_SPINLOCK(bcm1480_imr_lock);
+
+void bcm1480_mask_irq(int cpu, int irq)
+{
+	unsigned long flags, hl_spacing;
+	u64 cur_ints;
+
+	raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
+	hl_spacing = 0;
+	if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
+		hl_spacing = BCM1480_IMR_HL_SPACING;
+		irq -= BCM1480_NR_IRQS_HALF;
+	}
+	cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
+	cur_ints |= (((u64) 1) << irq);
+	____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
+	raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
+}
+
+void bcm1480_unmask_irq(int cpu, int irq)
+{
+	unsigned long flags, hl_spacing;
+	u64 cur_ints;
+
+	raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
+	hl_spacing = 0;
+	if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
+		hl_spacing = BCM1480_IMR_HL_SPACING;
+		irq -= BCM1480_NR_IRQS_HALF;
+	}
+	cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
+	cur_ints &= ~(((u64) 1) << irq);
+	____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
+	raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
+}
+
+#ifdef CONFIG_SMP
+static int bcm1480_set_affinity(struct irq_data *d, const struct cpumask *mask,
+				bool force)
+{
+	unsigned int irq_dirty, irq = d->irq;
+	int i = 0, old_cpu, cpu, int_on, k;
+	u64 cur_ints;
+	unsigned long flags;
+
+	i = cpumask_first_and(mask, cpu_online_mask);
+
+	/* Convert logical CPU to physical CPU */
+	cpu = cpu_logical_map(i);
+
+	/* Protect against other affinity changers and IMR manipulation */
+	raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
+
+	/* Swizzle each CPU's IMR (but leave the IP selection alone) */
+	old_cpu = bcm1480_irq_owner[irq];
+	irq_dirty = irq;
+	if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
+		irq_dirty -= BCM1480_NR_IRQS_HALF;
+	}
+
+	for (k=0; k<2; k++) { /* Loop through high and low interrupt mask register */
+		cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
+		int_on = !(cur_ints & (((u64) 1) << irq_dirty));
+		if (int_on) {
+			/* If it was on, mask it */
+			cur_ints |= (((u64) 1) << irq_dirty);
+			____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
+		}
+		bcm1480_irq_owner[irq] = cpu;
+		if (int_on) {
+			/* unmask for the new CPU */
+			cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
+			cur_ints &= ~(((u64) 1) << irq_dirty);
+			____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
+		}
+	}
+	raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
+
+	return 0;
+}
+#endif
+
+
+/*****************************************************************************/
+
+static void disable_bcm1480_irq(struct irq_data *d)
+{
+	unsigned int irq = d->irq;
+
+	bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
+}
+
+static void enable_bcm1480_irq(struct irq_data *d)
+{
+	unsigned int irq = d->irq;
+
+	bcm1480_unmask_irq(bcm1480_irq_owner[irq], irq);
+}
+
+
+static void ack_bcm1480_irq(struct irq_data *d)
+{
+	unsigned int irq_dirty, irq = d->irq;
+	u64 pending;
+	int k;
+
+	/*
+	 * If the interrupt was an HT interrupt, now is the time to
+	 * clear it.  NOTE: we assume the HT bridge was set up to
+	 * deliver the interrupts to all CPUs (which makes affinity
+	 * changing easier for us)
+	 */
+	irq_dirty = irq;
+	if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
+		irq_dirty -= BCM1480_NR_IRQS_HALF;
+	}
+	for (k=0; k<2; k++) { /* Loop through high and low LDT interrupts */
+		pending = __raw_readq(IOADDR(A_BCM1480_IMR_REGISTER(bcm1480_irq_owner[irq],
+						R_BCM1480_IMR_LDT_INTERRUPT_H + (k*BCM1480_IMR_HL_SPACING))));
+		pending &= ((u64)1 << (irq_dirty));
+		if (pending) {
+#ifdef CONFIG_SMP
+			int i;
+			for (i=0; i<NR_CPUS; i++) {
+				/*
+				 * Clear for all CPUs so an affinity switch
+				 * doesn't find an old status
+				 */
+				__raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(cpu_logical_map(i),
+								R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
+			}
+#else
+			__raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
+#endif
+
+			/*
+			 * Generate EOI.  For Pass 1 parts, EOI is a nop.  For
+			 * Pass 2, the LDT world may be edge-triggered, but
+			 * this EOI shouldn't hurt.  If they are
+			 * level-sensitive, the EOI is required.
+			 */
+#ifdef CONFIG_PCI
+			if (ht_eoi_space)
+				*(uint32_t *)(ht_eoi_space+(irq<<16)+(7<<2)) = 0;
+#endif
+		}
+	}
+	bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
+}
+
+static struct irq_chip bcm1480_irq_type = {
+	.name = "BCM1480-IMR",
+	.irq_mask_ack = ack_bcm1480_irq,
+	.irq_mask = disable_bcm1480_irq,
+	.irq_unmask = enable_bcm1480_irq,
+#ifdef CONFIG_SMP
+	.irq_set_affinity = bcm1480_set_affinity
+#endif
+};
+
+void __init init_bcm1480_irqs(void)
+{
+	int i;
+
+	for (i = 0; i < BCM1480_NR_IRQS; i++) {
+		irq_set_chip_and_handler(i, &bcm1480_irq_type,
+					 handle_level_irq);
+		bcm1480_irq_owner[i] = 0;
+	}
+}
+
+/*
+ *  init_IRQ is called early in the boot sequence from init/main.c.  It
+ *  is responsible for setting up the interrupt mapper and installing the
+ *  handler that will be responsible for dispatching interrupts to the
+ *  "right" place.
+ */
+/*
+ * For now, map all interrupts to IP[2].  We could save
+ * some cycles by parceling out system interrupts to different
+ * IP lines, but keep it simple for bringup.  We'll also direct
+ * all interrupts to a single CPU; we should probably route
+ * PCI and LDT to one cpu and everything else to the other
+ * to balance the load a bit.
+ *
+ * On the second cpu, everything is set to IP5, which is
+ * ignored, EXCEPT the mailbox interrupt.  That one is
+ * set to IP[2] so it is handled.  This is needed so we
+ * can do cross-cpu function calls, as required by SMP
+ */
+
+#define IMR_IP2_VAL	K_BCM1480_INT_MAP_I0
+#define IMR_IP3_VAL	K_BCM1480_INT_MAP_I1
+#define IMR_IP4_VAL	K_BCM1480_INT_MAP_I2
+#define IMR_IP5_VAL	K_BCM1480_INT_MAP_I3
+#define IMR_IP6_VAL	K_BCM1480_INT_MAP_I4
+
+void __init arch_init_irq(void)
+{
+	unsigned int i, cpu;
+	u64 tmp;
+	unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
+		STATUSF_IP1 | STATUSF_IP0;
+
+	/* Default everything to IP2 */
+	/* Start with _high registers which has no bit 0 interrupt source */
+	for (i = 1; i < BCM1480_NR_IRQS_HALF; i++) {	/* was I0 */
+		for (cpu = 0; cpu < 4; cpu++) {
+			__raw_writeq(IMR_IP2_VAL,
+				     IOADDR(A_BCM1480_IMR_REGISTER(cpu,
+								   R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) + (i << 3)));
+		}
+	}
+
+	/* Now do _low registers */
+	for (i = 0; i < BCM1480_NR_IRQS_HALF; i++) {
+		for (cpu = 0; cpu < 4; cpu++) {
+			__raw_writeq(IMR_IP2_VAL,
+				     IOADDR(A_BCM1480_IMR_REGISTER(cpu,
+								   R_BCM1480_IMR_INTERRUPT_MAP_BASE_L) + (i << 3)));
+		}
+	}
+
+	init_bcm1480_irqs();
+
+	/*
+	 * Map the high 16 bits of mailbox_0 registers to IP[3], for
+	 * inter-cpu messages
+	 */
+	/* Was I1 */
+	for (cpu = 0; cpu < 4; cpu++) {
+		__raw_writeq(IMR_IP3_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) +
+						 (K_BCM1480_INT_MBOX_0_0 << 3)));
+	}
+
+
+	/* Clear the mailboxes.	 The firmware may leave them dirty */
+	for (cpu = 0; cpu < 4; cpu++) {
+		__raw_writeq(0xffffffffffffffffULL,
+			     IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_0_CLR_CPU)));
+		__raw_writeq(0xffffffffffffffffULL,
+			     IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_1_CLR_CPU)));
+	}
+
+
+	/* Mask everything except the high 16 bit of mailbox_0 registers for all cpus */
+	tmp = ~((u64) 0) ^ ( (((u64) 1) << K_BCM1480_INT_MBOX_0_0));
+	for (cpu = 0; cpu < 4; cpu++) {
+		__raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_H)));
+	}
+	tmp = ~((u64) 0);
+	for (cpu = 0; cpu < 4; cpu++) {
+		__raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_L)));
+	}
+
+	/*
+	 * Note that the timer interrupts are also mapped, but this is
+	 * done in bcm1480_time_init().	 Also, the profiling driver
+	 * does its own management of IP7.
+	 */
+
+	/* Enable necessary IPs, disable the rest */
+	change_c0_status(ST0_IM, imask);
+}
+
+extern void bcm1480_mailbox_interrupt(void);
+
+static inline void dispatch_ip2(void)
+{
+	unsigned long long mask_h, mask_l;
+	unsigned int cpu = smp_processor_id();
+	unsigned long base;
+
+	/*
+	 * Default...we've hit an IP[2] interrupt, which means we've got to
+	 * check the 1480 interrupt registers to figure out what to do.	 Need
+	 * to detect which CPU we're on, now that smp_affinity is supported.
+	 */
+	base = A_BCM1480_IMR_MAPPER(cpu);
+	mask_h = __raw_readq(
+		IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_H));
+	mask_l = __raw_readq(
+		IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_L));
+
+	if (mask_h) {
+		if (mask_h ^ 1)
+			do_IRQ(fls64(mask_h) - 1);
+		else if (mask_l)
+			do_IRQ(63 + fls64(mask_l));
+	}
+}
+
+asmlinkage void plat_irq_dispatch(void)
+{
+	unsigned int cpu = smp_processor_id();
+	unsigned int pending;
+
+	pending = read_c0_cause() & read_c0_status();
+
+	if (pending & CAUSEF_IP4)
+		do_IRQ(K_BCM1480_INT_TIMER_0 + cpu);
+#ifdef CONFIG_SMP
+	else if (pending & CAUSEF_IP3)
+		bcm1480_mailbox_interrupt();
+#endif
+
+	else if (pending & CAUSEF_IP2)
+		dispatch_ip2();
+}
-- 
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