[PATCH v3 12/16] ARM: mmp: add SMP support

From: Lubomir Rintel
Date: Fri Aug 30 2019 - 18:17:13 EST


Used to bring up the second core on MMP3.

Signed-off-by: Lubomir Rintel <lkundrak@xxxxx>

---
Changes since v2:
- Wrap secondary_startup with __pa_symbol(), instead of
SW_BRANCH_VIRT_ADDR.

Changes since v1:
- Wrap SW_BRANCH_VIRT_ADDR with __pa_symbol()

arch/arm/mach-mmp/Makefile | 3 +++
arch/arm/mach-mmp/platsmp.c | 32 ++++++++++++++++++++++++++++++++
2 files changed, 35 insertions(+)
create mode 100644 arch/arm/mach-mmp/platsmp.c

diff --git a/arch/arm/mach-mmp/Makefile b/arch/arm/mach-mmp/Makefile
index 322c1c97dc900..7b3a7f979eece 100644
--- a/arch/arm/mach-mmp/Makefile
+++ b/arch/arm/mach-mmp/Makefile
@@ -22,6 +22,9 @@ ifeq ($(CONFIG_PM),y)
obj-$(CONFIG_CPU_PXA910) += pm-pxa910.o
obj-$(CONFIG_CPU_MMP2) += pm-mmp2.o
endif
+ifeq ($(CONFIG_SMP),y)
+obj-$(CONFIG_MACH_MMP3_DT) += platsmp.o
+endif

# board support
obj-$(CONFIG_MACH_ASPENITE) += aspenite.o
diff --git a/arch/arm/mach-mmp/platsmp.c b/arch/arm/mach-mmp/platsmp.c
new file mode 100644
index 0000000000000..c99405469bb4b
--- /dev/null
+++ b/arch/arm/mach-mmp/platsmp.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2019 Lubomir Rintel <lkundrak@xxxxx>
+ */
+#include <linux/io.h>
+#include <asm/smp_scu.h>
+#include <asm/smp.h>
+#include "addr-map.h"
+
+#define SW_BRANCH_VIRT_ADDR CIU_REG(0x24)
+
+static int mmp3_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+ /*
+ * Apparently, the boot ROM on the second core spins on this
+ * register becoming non-zero and then jumps to the address written
+ * there. No IPIs involved.
+ */
+ __raw_writel(__pa_symbol(secondary_startup), SW_BRANCH_VIRT_ADDR);
+ return 0;
+}
+
+static void mmp3_smp_prepare_cpus(unsigned int max_cpus)
+{
+ scu_enable(SCU_VIRT_BASE);
+}
+
+static const struct smp_operations mmp3_smp_ops __initconst = {
+ .smp_prepare_cpus = mmp3_smp_prepare_cpus,
+ .smp_boot_secondary = mmp3_boot_secondary,
+};
+CPU_METHOD_OF_DECLARE(mmp3_smp, "marvell,mmp3-smp", &mmp3_smp_ops);
--
2.21.0