ARM: mach-shmobile: sh73a0 SMP support

Add SMP support for ag5evm and the sh73a0 processor.

Onlining and offlining works well, but at this point
offlined processor cores are not put into sleep mode.

There is no spinlock for syncing the secondary core
with the first one in this implementation. The code
instead relies on the cpu_online() check in __cpu_up().

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 97 insertions, 0 deletions

diff --git a/arch/arm/mach-shmobile/smp-sh73a0.c b/arch/arm/mach-shmobile/smp-sh73a0.c
new file mode 100644
index 00000000000..4e71fd416cd
--- /dev/null
+++ b/arch/arm/mach-shmobile/smp-sh73a0.c
@@ -0,0 +1,97 @@
+/*
+ * SMP support for R-Mobile / SH-Mobile - sh73a0 portion
+ *
+ * Copyright (C) 2010  Magnus Damm
+ * Copyright (C) 2010  Takashi Yoshii
+ *
+ * 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; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <mach/common.h>
+#include <asm/smp_scu.h>
+#include <asm/smp_twd.h>
+#include <asm/hardware/gic.h>
+
+#define WUPCR		0xe6151010
+#define SRESCR		0xe6151018
+#define PSTR		0xe6151040
+#define SBAR            0xe6180020
+#define APARMBAREA      0xe6f10020
+
+static void __iomem *scu_base_addr(void)
+{
+	return (void __iomem *)0xf0000000;
+}
+
+static DEFINE_SPINLOCK(scu_lock);
+static unsigned long tmp;
+
+static void modify_scu_cpu_psr(unsigned long set, unsigned long clr)
+{
+	void __iomem *scu_base = scu_base_addr();
+
+	spin_lock(&scu_lock);
+	tmp = __raw_readl(scu_base + 8);
+	tmp &= ~clr;
+	tmp |= set;
+	spin_unlock(&scu_lock);
+
+	/* disable cache coherency after releasing the lock */
+	__raw_writel(tmp, scu_base + 8);
+}
+
+unsigned int __init sh73a0_get_core_count(void)
+{
+	void __iomem *scu_base = scu_base_addr();
+
+	return scu_get_core_count(scu_base);
+}
+
+void __cpuinit sh73a0_secondary_init(unsigned int cpu)
+{
+	gic_cpu_init(0, __io(0xf0000100));
+}
+
+int __cpuinit sh73a0_boot_secondary(unsigned int cpu)
+{
+	/* enable cache coherency */
+	modify_scu_cpu_psr(0, 3 << (cpu * 8));
+
+	if (((__raw_readw(__io(PSTR)) >> (4 * cpu)) & 3) == 3)
+		__raw_writel(1 << cpu, __io(WUPCR));	/* wake up */
+	else
+		__raw_writel(1 << cpu, __io(SRESCR));	/* reset */
+
+	return 0;
+}
+
+void __init sh73a0_smp_prepare_cpus(void)
+{
+#ifdef CONFIG_HAVE_ARM_TWD
+	twd_base = (void __iomem *)0xf0000600;
+#endif
+
+	scu_enable(scu_base_addr());
+
+	/* Map the reset vector (in headsmp.S) */
+	__raw_writel(0, __io(APARMBAREA));      /* 4k */
+	__raw_writel(__pa(shmobile_secondary_vector), __io(SBAR));
+
+	/* enable cache coherency on CPU0 */
+	modify_scu_cpu_psr(0, 3 << (0 * 8));
+}