BCM23550 has a Cluster Dormant Control IP block that holds cores
in an idle state. Support a new CPU enable method in which the CDC is
accessed to bring the core online.
Signed-off-by: Raymond Ngun <raymond.ngun@xxxxxxxxxxxx>
Signed-off-by: Chris Brand <chris.brand@xxxxxxxxxxxx>
---
arch/arm/mach-bcm/platsmp.c | 58 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 58 insertions(+)
diff --git a/arch/arm/mach-bcm/platsmp.c b/arch/arm/mach-bcm/platsmp.c
index cfae9c71fb74..c57fc6b1ac07 100644
--- a/arch/arm/mach-bcm/platsmp.c
+++ b/arch/arm/mach-bcm/platsmp.c
@@ -19,6 +19,7 @@
#include <linux/io.h>
#include <linux/jiffies.h>
#include <linux/of.h>
+#include <linux/of_address.h>
#include <linux/sched.h>
#include <linux/smp.h>
@@ -255,6 +256,57 @@ static int kona_boot_secondary(unsigned int cpu, struct task_struct *idle)
return -ENXIO;
}
+/* Cluster Dormant Control command to bring CPU into a running state */
+#define CDC_CMD 6
+#define CDC_CMD_OFFSET 0
+#define CDC_CMD_REG(cpu) (CDC_CMD_OFFSET + 4*(cpu))
+
+/*
+ * BCM23550 has a Cluster Dormant Control block that keeps the core in
+ * idle state. A command needs to be sent to the block to bring the CPU
+ * into running state.
+ */
+static int bcm23550_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+ void __iomem *cdc_base;
+ struct device_node *dn;
+ char *name;
+ int ret;
+
+ /* Make sure a CDC node exists before booting the
+ * secondary core.
+ */
+ name = "brcm,bcm23550-cdc";
+ dn = of_find_compatible_node(NULL, NULL, name);
+ if (!dn) {
+ pr_err("unable to find cdc node\n");
+ return -ENODEV;
+ }
+
+ cdc_base = of_iomap(dn, 0);
+ of_node_put(dn);
+
+ if (!cdc_base) {
+ pr_err("unable to remap cdc base register\n");
+ return -ENOMEM;
+ }
+
+ /* Boot the secondary core */
+ ret = kona_boot_secondary(cpu, idle);
+ if (ret)
+ goto out;
+
+ /* Bring this CPU to RUN state so that nIRQ nFIQ
+ * signals are unblocked.
+ */
+ writel_relaxed(CDC_CMD, cdc_base + CDC_CMD_REG(cpu));
+
+out:
+ iounmap(cdc_base);
+
+ return ret;
+}
+
static int nsp_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
int ret;
@@ -283,6 +335,12 @@ static const struct smp_operations bcm_smp_ops __initconst = {
CPU_METHOD_OF_DECLARE(bcm_smp_bcm281xx, "brcm,bcm11351-cpu-method",
&bcm_smp_ops);
+static const struct smp_operations bcm23550_smp_ops __initconst = {
+ .smp_boot_secondary = bcm23550_boot_secondary,
+};
+CPU_METHOD_OF_DECLARE(bcm_smp_bcm23550, "brcm,bcm23550-cpu-method",
+ &bcm23550_smp_ops);
+
static const struct smp_operations nsp_smp_ops __initconst = {
.smp_prepare_cpus = bcm_smp_prepare_cpus,
.smp_boot_secondary = nsp_boot_secondary,
--
1.9.1
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