File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/mips/kernel/mips-cpc.c b/arch/mips/kernel/mips-cpc.c
new file mode 100644
index 0000000..566b8d2
--- /dev/null
+++ b/arch/mips/kernel/mips-cpc.c
@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2013 Imagination Technologies
+ * Author: Paul Burton <paul.burton@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/errno.h>
+#include <linux/percpu.h>
+#include <linux/spinlock.h>
+
+#include <asm/mips-cm.h>
+#include <asm/mips-cpc.h>
+
+void __iomem *mips_cpc_base;
+
+static DEFINE_PER_CPU_ALIGNED(spinlock_t, cpc_core_lock);
+
+static DEFINE_PER_CPU_ALIGNED(unsigned long, cpc_core_lock_flags);
+
+/**
+ * mips_cpc_phys_base - retrieve the physical base address of the CPC
+ *
+ * This function returns the physical base address of the Cluster Power
+ * Controller memory mapped registers, or 0 if no Cluster Power Controller
+ * is present.
+ */
+static phys_addr_t mips_cpc_phys_base(void)
+{
+ unsigned long cpc_base;
+
+ if (!mips_cm_present())
+ return 0;
+
+ if (!(read_gcr_cpc_status() & CM_GCR_CPC_STATUS_EX_MSK))
+ return 0;
+
+ /* If the CPC is already enabled, leave it so */
+ cpc_base = read_gcr_cpc_base();
+ if (cpc_base & CM_GCR_CPC_BASE_CPCEN_MSK)
+ return cpc_base & CM_GCR_CPC_BASE_CPCBASE_MSK;
+
+ /* Otherwise, give it the default address & enable it */
+ cpc_base = mips_cpc_default_phys_base();
+ write_gcr_cpc_base(cpc_base | CM_GCR_CPC_BASE_CPCEN_MSK);
+ return cpc_base;
+}
+
+int mips_cpc_probe(void)
+{
+ phys_addr_t addr;
+ unsigned cpu;
+
+ for_each_possible_cpu(cpu)
+ spin_lock_init(&per_cpu(cpc_core_lock, cpu));
+
+ addr = mips_cpc_phys_base();
+ if (!addr)
+ return -ENODEV;
+
+ mips_cpc_base = ioremap_nocache(addr, 0x8000);
+ if (!mips_cpc_base)
+ return -ENXIO;
+
+ return 0;
+}
+
+void mips_cpc_lock_other(unsigned int core)
+{
+ unsigned curr_core;
+ preempt_disable();
+ curr_core = current_cpu_data.core;
+ spin_lock_irqsave(&per_cpu(cpc_core_lock, curr_core),
+ per_cpu(cpc_core_lock_flags, curr_core));
+ write_cpc_cl_other(core << CPC_Cx_OTHER_CORENUM_SHF);
+
+ /*
+ * Ensure the core-other region reflects the appropriate core &
+ * VP before any accesses to it occur.
+ */
+ mb();
+}
+
+void mips_cpc_unlock_other(void)
+{
+ unsigned curr_core = current_cpu_data.core;
+ spin_unlock_irqrestore(&per_cpu(cpc_core_lock, curr_core),
+ per_cpu(cpc_core_lock_flags, curr_core));
+ preempt_enable();
+}