--- zzzz-none-000/linux-3.10.107/drivers/tty/hvc/hvc_tile.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/tty/hvc/hvc_tile.c	2021-02-04 17:41:59.000000000 +0000
@@ -18,16 +18,47 @@
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
 #include <linux/moduleparam.h>
+#include <linux/platform_device.h>
 #include <linux/types.h>
 
+#include <asm/setup.h>
+#include <arch/sim_def.h>
+
 #include <hv/hypervisor.h>
 
 #include "hvc_console.h"
 
+static int use_sim_console;
+static int __init sim_console(char *str)
+{
+	use_sim_console = 1;
+	return 0;
+}
+early_param("sim_console", sim_console);
+
+int tile_console_write(const char *buf, int count)
+{
+	if (unlikely(use_sim_console)) {
+		int i;
+		for (i = 0; i < count; ++i)
+			__insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_PUTC |
+				     (buf[i] << _SIM_CONTROL_OPERATOR_BITS));
+		__insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_PUTC |
+			     (SIM_PUTC_FLUSH_BINARY <<
+			      _SIM_CONTROL_OPERATOR_BITS));
+		return 0;
+	} else {
+		/* Translate 0 bytes written to EAGAIN for hvc_console_print. */
+		return hv_console_write((HV_VirtAddr)buf, count) ?: -EAGAIN;
+	}
+}
+
 static int hvc_tile_put_chars(uint32_t vt, const char *buf, int count)
 {
-	return hv_console_write((HV_VirtAddr)buf, count);
+	return tile_console_write(buf, count);
 }
 
 static int hvc_tile_get_chars(uint32_t vt, char *buf, int count)
@@ -44,25 +75,131 @@
 	return i;
 }
 
+#ifdef __tilegx__
+/*
+ * IRQ based callbacks.
+ */
+static int hvc_tile_notifier_add_irq(struct hvc_struct *hp, int irq)
+{
+	int rc;
+	int cpu = raw_smp_processor_id();  /* Choose an arbitrary cpu */
+	HV_Coord coord = { .x = cpu_x(cpu), .y = cpu_y(cpu) };
+
+	rc = notifier_add_irq(hp, irq);
+	if (rc)
+		return rc;
+
+	/*
+	 * Request that the hypervisor start sending us interrupts.
+	 * If the hypervisor returns an error, we still return 0, so that
+	 * we can fall back to polling.
+	 */
+	if (hv_console_set_ipi(KERNEL_PL, irq, coord) < 0)
+		notifier_del_irq(hp, irq);
+
+	return 0;
+}
+
+static void hvc_tile_notifier_del_irq(struct hvc_struct *hp, int irq)
+{
+	HV_Coord coord = { 0, 0 };
+
+	/* Tell the hypervisor to stop sending us interrupts. */
+	hv_console_set_ipi(KERNEL_PL, -1, coord);
+
+	notifier_del_irq(hp, irq);
+}
+
+static void hvc_tile_notifier_hangup_irq(struct hvc_struct *hp, int irq)
+{
+	hvc_tile_notifier_del_irq(hp, irq);
+}
+#endif
+
 static const struct hv_ops hvc_tile_get_put_ops = {
 	.get_chars = hvc_tile_get_chars,
 	.put_chars = hvc_tile_put_chars,
+#ifdef __tilegx__
+	.notifier_add = hvc_tile_notifier_add_irq,
+	.notifier_del = hvc_tile_notifier_del_irq,
+	.notifier_hangup = hvc_tile_notifier_hangup_irq,
+#endif
+};
+
+
+#ifdef __tilegx__
+static int hvc_tile_probe(struct platform_device *pdev)
+{
+	struct hvc_struct *hp;
+	int tile_hvc_irq;
+
+	/* Create our IRQ and register it. */
+	tile_hvc_irq = irq_alloc_hwirq(-1);
+	if (!tile_hvc_irq)
+		return -ENXIO;
+
+	tile_irq_activate(tile_hvc_irq, TILE_IRQ_PERCPU);
+	hp = hvc_alloc(0, tile_hvc_irq, &hvc_tile_get_put_ops, 128);
+	if (IS_ERR(hp)) {
+		irq_free_hwirq(tile_hvc_irq);
+		return PTR_ERR(hp);
+	}
+	dev_set_drvdata(&pdev->dev, hp);
+
+	return 0;
+}
+
+static int hvc_tile_remove(struct platform_device *pdev)
+{
+	int rc;
+	struct hvc_struct *hp = dev_get_drvdata(&pdev->dev);
+
+	rc = hvc_remove(hp);
+	if (rc == 0)
+		irq_free_hwirq(hp->data);
+
+	return rc;
+}
+
+static void hvc_tile_shutdown(struct platform_device *pdev)
+{
+	struct hvc_struct *hp = dev_get_drvdata(&pdev->dev);
+
+	hvc_tile_notifier_del_irq(hp, hp->data);
+}
+
+static struct platform_device hvc_tile_pdev = {
+	.name           = "hvc-tile",
+	.id             = 0,
+};
+
+static struct platform_driver hvc_tile_driver = {
+	.probe          = hvc_tile_probe,
+	.remove         = hvc_tile_remove,
+	.shutdown	= hvc_tile_shutdown,
+	.driver         = {
+		.name   = "hvc-tile",
+	}
 };
+#endif
 
 static int __init hvc_tile_console_init(void)
 {
-	extern void disable_early_printk(void);
 	hvc_instantiate(0, 0, &hvc_tile_get_put_ops);
 	add_preferred_console("hvc", 0, NULL);
-	disable_early_printk();
 	return 0;
 }
 console_initcall(hvc_tile_console_init);
 
 static int __init hvc_tile_init(void)
 {
-	struct hvc_struct *s;
-	s = hvc_alloc(0, 0, &hvc_tile_get_put_ops, 128);
-	return IS_ERR(s) ? PTR_ERR(s) : 0;
+#ifndef __tilegx__
+	struct hvc_struct *hp;
+	hp = hvc_alloc(0, 0, &hvc_tile_get_put_ops, 128);
+	return PTR_ERR_OR_ZERO(hp);
+#else
+	platform_device_register(&hvc_tile_pdev);
+	return platform_driver_register(&hvc_tile_driver);
+#endif
 }
 device_initcall(hvc_tile_init);