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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/arm/mach-prima2/platsmp.c
Initial import
Diffstat (limited to 'arch/arm/mach-prima2/platsmp.c')
-rw-r--r--arch/arm/mach-prima2/platsmp.c121
1 files changed, 121 insertions, 0 deletions
diff --git a/arch/arm/mach-prima2/platsmp.c b/arch/arm/mach-prima2/platsmp.c
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+++ b/arch/arm/mach-prima2/platsmp.c
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+/*
+ * 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(virt_to_phys(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;
+}
+
+struct smp_operations sirfsoc_smp_ops __initdata = {
+ .smp_secondary_init = sirfsoc_secondary_init,
+ .smp_boot_secondary = sirfsoc_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+ .cpu_die = sirfsoc_cpu_die,
+#endif
+};