v4.19.13 snapshot.
diff --git a/arch/arm/mach-vexpress/dcscb.c b/arch/arm/mach-vexpress/dcscb.c
new file mode 100644
index 0000000..ee2a0fa
--- /dev/null
+++ b/arch/arm/mach-vexpress/dcscb.c
@@ -0,0 +1,174 @@
+/*
+ * arch/arm/mach-vexpress/dcscb.c - Dual Cluster System Configuration Block
+ *
+ * Created by: Nicolas Pitre, May 2012
+ * Copyright: (C) 2012-2013 Linaro Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/errno.h>
+#include <linux/of_address.h>
+#include <linux/vexpress.h>
+#include <linux/arm-cci.h>
+
+#include <asm/mcpm.h>
+#include <asm/proc-fns.h>
+#include <asm/cacheflush.h>
+#include <asm/cputype.h>
+#include <asm/cp15.h>
+
+
+#define RST_HOLD0 0x0
+#define RST_HOLD1 0x4
+#define SYS_SWRESET 0x8
+#define RST_STAT0 0xc
+#define RST_STAT1 0x10
+#define EAG_CFG_R 0x20
+#define EAG_CFG_W 0x24
+#define KFC_CFG_R 0x28
+#define KFC_CFG_W 0x2c
+#define DCS_CFG_R 0x30
+
+static void __iomem *dcscb_base;
+static int dcscb_allcpus_mask[2];
+
+static int dcscb_cpu_powerup(unsigned int cpu, unsigned int cluster)
+{
+ unsigned int rst_hold, cpumask = (1 << cpu);
+
+ pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
+ if (cluster >= 2 || !(cpumask & dcscb_allcpus_mask[cluster]))
+ return -EINVAL;
+
+ rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4);
+ rst_hold &= ~(cpumask | (cpumask << 4));
+ writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4);
+ return 0;
+}
+
+static int dcscb_cluster_powerup(unsigned int cluster)
+{
+ unsigned int rst_hold;
+
+ pr_debug("%s: cluster %u\n", __func__, cluster);
+ if (cluster >= 2)
+ return -EINVAL;
+
+ /* remove cluster reset and add individual CPU's reset */
+ rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4);
+ rst_hold &= ~(1 << 8);
+ rst_hold |= dcscb_allcpus_mask[cluster];
+ writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4);
+ return 0;
+}
+
+static void dcscb_cpu_powerdown_prepare(unsigned int cpu, unsigned int cluster)
+{
+ unsigned int rst_hold;
+
+ pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
+ BUG_ON(cluster >= 2 || !((1 << cpu) & dcscb_allcpus_mask[cluster]));
+
+ rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4);
+ rst_hold |= (1 << cpu);
+ writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4);
+}
+
+static void dcscb_cluster_powerdown_prepare(unsigned int cluster)
+{
+ unsigned int rst_hold;
+
+ pr_debug("%s: cluster %u\n", __func__, cluster);
+ BUG_ON(cluster >= 2);
+
+ rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4);
+ rst_hold |= (1 << 8);
+ writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4);
+}
+
+static void dcscb_cpu_cache_disable(void)
+{
+ /* Disable and flush the local CPU cache. */
+ v7_exit_coherency_flush(louis);
+}
+
+static void dcscb_cluster_cache_disable(void)
+{
+ /* Flush all cache levels for this cluster. */
+ v7_exit_coherency_flush(all);
+
+ /*
+ * A full outer cache flush could be needed at this point
+ * on platforms with such a cache, depending on where the
+ * outer cache sits. In some cases the notion of a "last
+ * cluster standing" would need to be implemented if the
+ * outer cache is shared across clusters. In any case, when
+ * the outer cache needs flushing, there is no concurrent
+ * access to the cache controller to worry about and no
+ * special locking besides what is already provided by the
+ * MCPM state machinery is needed.
+ */
+
+ /*
+ * Disable cluster-level coherency by masking
+ * incoming snoops and DVM messages:
+ */
+ cci_disable_port_by_cpu(read_cpuid_mpidr());
+}
+
+static const struct mcpm_platform_ops dcscb_power_ops = {
+ .cpu_powerup = dcscb_cpu_powerup,
+ .cluster_powerup = dcscb_cluster_powerup,
+ .cpu_powerdown_prepare = dcscb_cpu_powerdown_prepare,
+ .cluster_powerdown_prepare = dcscb_cluster_powerdown_prepare,
+ .cpu_cache_disable = dcscb_cpu_cache_disable,
+ .cluster_cache_disable = dcscb_cluster_cache_disable,
+};
+
+extern void dcscb_power_up_setup(unsigned int affinity_level);
+
+static int __init dcscb_init(void)
+{
+ struct device_node *node;
+ unsigned int cfg;
+ int ret;
+
+ if (!cci_probed())
+ return -ENODEV;
+
+ node = of_find_compatible_node(NULL, NULL, "arm,rtsm,dcscb");
+ if (!node)
+ return -ENODEV;
+ dcscb_base = of_iomap(node, 0);
+ if (!dcscb_base)
+ return -EADDRNOTAVAIL;
+ cfg = readl_relaxed(dcscb_base + DCS_CFG_R);
+ dcscb_allcpus_mask[0] = (1 << (((cfg >> 16) >> (0 << 2)) & 0xf)) - 1;
+ dcscb_allcpus_mask[1] = (1 << (((cfg >> 16) >> (1 << 2)) & 0xf)) - 1;
+
+ ret = mcpm_platform_register(&dcscb_power_ops);
+ if (!ret)
+ ret = mcpm_sync_init(dcscb_power_up_setup);
+ if (ret) {
+ iounmap(dcscb_base);
+ return ret;
+ }
+
+ pr_info("VExpress DCSCB support installed\n");
+
+ /*
+ * Future entries into the kernel can now go
+ * through the cluster entry vectors.
+ */
+ vexpress_flags_set(__pa_symbol(mcpm_entry_point));
+
+ return 0;
+}
+
+early_initcall(dcscb_init);