Blackfin arch: SMP supporting patchset: BF561 related code

Blackfin dual core BF561 processor can support SMP like features.
https://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:smp-like

In this patch, we provide SMP extend to BF561 kernel code

Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

1 files changed, 172 insertions, 0 deletions

diff --git a/arch/blackfin/mach-bf561/smp.c b/arch/blackfin/mach-bf561/smp.c
new file mode 100644
index 000000000000..23fd4c13897f
--- /dev/null
+++ b/arch/blackfin/mach-bf561/smp.c
@@ -0,0 +1,172 @@
+/*
+ * File:         arch/blackfin/mach-bf561/smp.c
+ * Author:       Philippe Gerum <rpm@xenomai.org>
+ *
+ *               Copyright 2007 Analog Devices Inc.
+ *
+ * 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.
+ *
+ * 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, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <asm/smp.h>
+#include <asm/dma.h>
+
+#define COREB_SRAM_BASE  0xff600000
+#define COREB_SRAM_SIZE  0x4000
+
+extern char coreb_trampoline_start, coreb_trampoline_end;
+
+static DEFINE_SPINLOCK(boot_lock);
+
+static cpumask_t cpu_callin_map;
+
+/*
+ * platform_init_cpus() - Tell the world about how many cores we
+ * have. This is called while setting up the architecture support
+ * (setup_arch()), so don't be too demanding here with respect to
+ * available kernel services.
+ */
+
+void __init platform_init_cpus(void)
+{
+	cpu_set(0, cpu_possible_map); /* CoreA */
+	cpu_set(1, cpu_possible_map); /* CoreB */
+}
+
+void __init platform_prepare_cpus(unsigned int max_cpus)
+{
+	int len;
+
+	len = &coreb_trampoline_end - &coreb_trampoline_start + 1;
+	BUG_ON(len > COREB_SRAM_SIZE);
+
+	dma_memcpy((void *)COREB_SRAM_BASE, &coreb_trampoline_start, len);
+
+	/* Both cores ought to be present on a bf561! */
+	cpu_set(0, cpu_present_map); /* CoreA */
+	cpu_set(1, cpu_present_map); /* CoreB */
+
+	printk(KERN_INFO "CoreB bootstrap code to SRAM %p via DMA.\n", (void *)COREB_SRAM_BASE);
+}
+
+int __init setup_profiling_timer(unsigned int multiplier) /* not supported */
+{
+	return -EINVAL;
+}
+
+void __cpuinit platform_secondary_init(unsigned int cpu)
+{
+	local_irq_disable();
+
+	/* Clone setup for peripheral interrupt sources from CoreA. */
+	bfin_write_SICB_IMASK0(bfin_read_SICA_IMASK0());
+	bfin_write_SICB_IMASK1(bfin_read_SICA_IMASK1());
+	SSYNC();
+
+	/* Clone setup for IARs from CoreA. */
+	bfin_write_SICB_IAR0(bfin_read_SICA_IAR0());
+	bfin_write_SICB_IAR1(bfin_read_SICA_IAR1());
+	bfin_write_SICB_IAR2(bfin_read_SICA_IAR2());
+	bfin_write_SICB_IAR3(bfin_read_SICA_IAR3());
+	bfin_write_SICB_IAR4(bfin_read_SICA_IAR4());
+	bfin_write_SICB_IAR5(bfin_read_SICA_IAR5());
+	bfin_write_SICB_IAR6(bfin_read_SICA_IAR6());
+	bfin_write_SICB_IAR7(bfin_read_SICA_IAR7());
+	SSYNC();
+
+	local_irq_enable();
+
+	/* Calibrate loops per jiffy value. */
+	calibrate_delay();
+
+	/* Store CPU-private information to the cpu_data array. */
+	bfin_setup_cpudata(cpu);
+
+	/* We are done with local CPU inits, unblock the boot CPU. */
+	cpu_set(cpu, cpu_callin_map);
+	spin_lock(&boot_lock);
+	spin_unlock(&boot_lock);
+}
+
+int __cpuinit platform_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+	unsigned long timeout;
+
+	/* CoreB already running?! */
+	BUG_ON((bfin_read_SICA_SYSCR() & COREB_SRAM_INIT) == 0);
+
+	printk(KERN_INFO "Booting Core B.\n");
+
+	spin_lock(&boot_lock);
+
+	/* Kick CoreB, which should start execution from CORE_SRAM_BASE. */
+	SSYNC();
+	bfin_write_SICA_SYSCR(bfin_read_SICA_SYSCR() & ~COREB_SRAM_INIT);
+	SSYNC();
+
+	timeout = jiffies + 1 * HZ;
+	while (time_before(jiffies, timeout)) {
+		if (cpu_isset(cpu, cpu_callin_map))
+			break;
+		udelay(100);
+		barrier();
+	}
+
+	spin_unlock(&boot_lock);
+
+	return cpu_isset(cpu, cpu_callin_map) ? 0 : -ENOSYS;
+}
+
+void __init platform_request_ipi(irq_handler_t handler)
+{
+	int ret;
+
+	ret = request_irq(IRQ_SUPPLE_0, handler, IRQF_DISABLED,
+			  "SMP interrupt", handler);
+	if (ret)
+		panic("Cannot request supplemental interrupt 0 for IPI service\n");
+}
+
+void platform_send_ipi(cpumask_t callmap)
+{
+	unsigned int cpu;
+
+	for_each_cpu_mask(cpu, callmap) {
+		BUG_ON(cpu >= 2);
+		SSYNC();
+		bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | (1 << (6 + cpu)));
+		SSYNC();
+	}
+}
+
+void platform_send_ipi_cpu(unsigned int cpu)
+{
+	BUG_ON(cpu >= 2);
+	SSYNC();
+	bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | (1 << (6 + cpu)));
+	SSYNC();
+}
+
+void platform_clear_ipi(unsigned int cpu)
+{
+	BUG_ON(cpu >= 2);
+	SSYNC();
+	bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | (1 << (10 + cpu)));
+	SSYNC();
+}