From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Mon, 6 May 2024 03:02:30 +0200
Subject: Adding upstream version 4.19.249.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 arch/arm/mach-prima2/platsmp.c | 121 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 121 insertions(+)
 create mode 100644 arch/arm/mach-prima2/platsmp.c

(limited to 'arch/arm/mach-prima2/platsmp.c')

diff --git a/arch/arm/mach-prima2/platsmp.c b/arch/arm/mach-prima2/platsmp.c
new file mode 100644
index 000000000..75ef5d4be
--- /dev/null
+++ b/arch/arm/mach-prima2/platsmp.c
@@ -0,0 +1,121 @@
+/*
+ * plat smp support for CSR Marco dual-core SMP SoCs
+ *
+ * Copyright (c) 2012 Cambridge Silicon Radio Limited, a CSR plc group company.
+ *
+ * Licensed under GPLv2 or later.
+ */
+
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <asm/page.h>
+#include <asm/mach/map.h>
+#include <asm/smp_plat.h>
+#include <asm/smp_scu.h>
+#include <asm/cacheflush.h>
+#include <asm/cputype.h>
+
+#include "common.h"
+
+static void __iomem *clk_base;
+
+static DEFINE_SPINLOCK(boot_lock);
+
+static void sirfsoc_secondary_init(unsigned int cpu)
+{
+	/*
+	 * let the primary processor know we're out of the
+	 * pen, then head off into the C entry point
+	 */
+	pen_release = -1;
+	smp_wmb();
+
+	/*
+	 * Synchronise with the boot thread.
+	 */
+	spin_lock(&boot_lock);
+	spin_unlock(&boot_lock);
+}
+
+static const struct of_device_id clk_ids[]  = {
+	{ .compatible = "sirf,atlas7-clkc" },
+	{},
+};
+
+static int sirfsoc_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+	unsigned long timeout;
+	struct device_node *np;
+
+	np = of_find_matching_node(NULL, clk_ids);
+	if (!np)
+		return -ENODEV;
+
+	clk_base = of_iomap(np, 0);
+	if (!clk_base)
+		return -ENOMEM;
+
+	/*
+	 * write the address of secondary startup into the clkc register
+	 * at offset 0x2bC, then write the magic number 0x3CAF5D62 to the
+	 * clkc register at offset 0x2b8, which is what boot rom code is
+	 * waiting for. This would wake up the secondary core from WFE
+	 */
+#define SIRFSOC_CPU1_JUMPADDR_OFFSET 0x2bc
+	__raw_writel(__pa_symbol(sirfsoc_secondary_startup),
+		clk_base + SIRFSOC_CPU1_JUMPADDR_OFFSET);
+
+#define SIRFSOC_CPU1_WAKEMAGIC_OFFSET 0x2b8
+	__raw_writel(0x3CAF5D62,
+		clk_base + SIRFSOC_CPU1_WAKEMAGIC_OFFSET);
+
+	/* make sure write buffer is drained */
+	mb();
+
+	spin_lock(&boot_lock);
+
+	/*
+	 * The secondary processor is waiting to be released from
+	 * the holding pen - release it, then wait for it to flag
+	 * that it has been released by resetting pen_release.
+	 *
+	 * Note that "pen_release" is the hardware CPU ID, whereas
+	 * "cpu" is Linux's internal ID.
+	 */
+	pen_release = cpu_logical_map(cpu);
+	sync_cache_w(&pen_release);
+
+	/*
+	 * Send the secondary CPU SEV, thereby causing the boot monitor to read
+	 * the JUMPADDR and WAKEMAGIC, and branch to the address found there.
+	 */
+	dsb_sev();
+
+	timeout = jiffies + (1 * HZ);
+	while (time_before(jiffies, timeout)) {
+		smp_rmb();
+		if (pen_release == -1)
+			break;
+
+		udelay(10);
+	}
+
+	/*
+	 * now the secondary core is starting up let it run its
+	 * calibrations, then wait for it to finish
+	 */
+	spin_unlock(&boot_lock);
+
+	return pen_release != -1 ? -ENOSYS : 0;
+}
+
+const struct smp_operations sirfsoc_smp_ops __initconst = {
+	.smp_secondary_init     = sirfsoc_secondary_init,
+	.smp_boot_secondary     = sirfsoc_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+	.cpu_die                = sirfsoc_cpu_die,
+#endif
+};
-- 
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