arm/imx6q: add smp and cpu hotplug support

It adds smp and cpu hotplug support for imx6q.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

7 files changed, 246 insertions, 0 deletions

diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
index 40372a8e301..66b86489384 100644
--- a/arch/arm/mach-imx/Kconfig
+++ b/arch/arm/mach-imx/Kconfig
@@ -611,6 +611,7 @@ config SOC_IMX6Q
         select ARM_GIC
         select CACHE_L2X0
         select CPU_V7
+        select HAVE_ARM_SCU
         select HAVE_IMX_GPC
         select HAVE_IMX_MMDC
         select HAVE_IMX_SRC
diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
index 65218d98a78..f1098507a88 100644
--- a/arch/arm/mach-imx/Makefile
+++ b/arch/arm/mach-imx/Makefile
@@ -65,4 +65,9 @@ obj-$(CONFIG_DEBUG_LL) += lluart.o
 obj-$(CONFIG_HAVE_IMX_GPC) += gpc.o
 obj-$(CONFIG_HAVE_IMX_MMDC) += mmdc.o
 obj-$(CONFIG_HAVE_IMX_SRC) += src.o
+obj-$(CONFIG_CPU_V7) += head-v7.o
+AFLAGS_head-v7.o :=-Wa,-march=armv7-a
+obj-$(CONFIG_SMP) += platsmp.o
+obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
+obj-$(CONFIG_LOCAL_TIMERS) += localtimer.o
 obj-$(CONFIG_SOC_IMX6Q) += clock-imx6q.o
diff --git a/arch/arm/mach-imx/head-v7.S b/arch/arm/mach-imx/head-v7.S
new file mode 100644
index 00000000000..ede908bca7d
--- /dev/null
+++ b/arch/arm/mach-imx/head-v7.S
@@ -0,0 +1,71 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc.
+ * Copyright 2011 Linaro Ltd.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/hardware/cache-l2x0.h>
+
+        .section ".text.head", "ax"
+        __CPUINIT
+
+/*
+ * The secondary kernel init calls v7_flush_dcache_all before it enables
+ * the L1; however, the L1 comes out of reset in an undefined state, so
+ * the clean + invalidate performed by v7_flush_dcache_all causes a bunch
+ * of cache lines with uninitialized data and uninitialized tags to get
+ * written out to memory, which does really unpleasant things to the main
+ * processor.  We fix this by performing an invalidate, rather than a
+ * clean + invalidate, before jumping into the kernel.
+ *
+ * This funciton is cloned from arch/arm/mach-tegra/headsmp.S, and needs
+ * to be called for both secondary cores startup and primary core resume
+ * procedures.  Ideally, it should be moved into arch/arm/mm/cache-v7.S.
+ */
+ENTRY(v7_invalidate_l1)
+        mov     r0, #0
+        mcr     p15, 2, r0, c0, c0, 0
+        mrc     p15, 1, r0, c0, c0, 0
+
+        ldr     r1, =0x7fff
+        and     r2, r1, r0, lsr #13
+
+        ldr     r1, =0x3ff
+
+        and     r3, r1, r0, lsr #3      @ NumWays - 1
+        add     r2, r2, #1              @ NumSets
+
+        and     r0, r0, #0x7
+        add     r0, r0, #4      @ SetShift
+
+        clz     r1, r3          @ WayShift
+        add     r4, r3, #1      @ NumWays
+1:      sub     r2, r2, #1      @ NumSets--
+        mov     r3, r4          @ Temp = NumWays
+2:      subs    r3, r3, #1      @ Temp--
+        mov     r5, r3, lsl r1
+        mov     r6, r2, lsl r0
+        orr     r5, r5, r6      @ Reg = (Temp<<WayShift)|(NumSets<<SetShift)
+        mcr     p15, 0, r5, c7, c6, 2
+        bgt     2b
+        cmp     r2, #0
+        bgt     1b
+        dsb
+        isb
+        mov     pc, lr
+ENDPROC(v7_invalidate_l1)
+
+#ifdef CONFIG_SMP
+ENTRY(v7_secondary_startup)
+        bl      v7_invalidate_l1
+        b       secondary_startup
+ENDPROC(v7_secondary_startup)
+#endif
diff --git a/arch/arm/mach-imx/hotplug.c b/arch/arm/mach-imx/hotplug.c
new file mode 100644
index 00000000000..89493abd497
--- /dev/null
+++ b/arch/arm/mach-imx/hotplug.c
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc.
+ * Copyright 2011 Linaro Ltd.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/errno.h>
+#include <asm/cacheflush.h>
+#include <mach/common.h>
+
+int platform_cpu_kill(unsigned int cpu)
+{
+        return 1;
+}
+
+/*
+ * platform-specific code to shutdown a CPU
+ *
+ * Called with IRQs disabled
+ */
+void platform_cpu_die(unsigned int cpu)
+{
+        flush_cache_all();
+        imx_enable_cpu(cpu, false);
+        cpu_do_idle();
+
+        /* We should never return from idle */
+        panic("cpu %d unexpectedly exit from shutdown\n", cpu);
+}
+
+int platform_cpu_disable(unsigned int cpu)
+{
+        /*
+         * we don't allow CPU 0 to be shutdown (it is still too special
+         * e.g. clock tick interrupts)
+         */
+        return cpu == 0 ? -EPERM : 0;
+}
diff --git a/arch/arm/mach-imx/localtimer.c b/arch/arm/mach-imx/localtimer.c
new file mode 100644
index 00000000000..3a163515d41
--- /dev/null
+++ b/arch/arm/mach-imx/localtimer.c
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc.
+ * Copyright 2011 Linaro Ltd.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/init.h>
+#include <linux/clockchips.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <asm/smp_twd.h>
+
+/*
+ * Setup the local clock events for a CPU.
+ */
+int __cpuinit local_timer_setup(struct clock_event_device *evt)
+{
+        struct device_node *np;
+
+        np = of_find_compatible_node(NULL, NULL, "arm,smp-twd");
+        if (!twd_base) {
+                twd_base = of_iomap(np, 0);
+                WARN_ON(!twd_base);
+        }
+        evt->irq = irq_of_parse_and_map(np, 0);
+        twd_timer_setup(evt);
+
+        return 0;
+}
diff --git a/arch/arm/mach-imx/platsmp.c b/arch/arm/mach-imx/platsmp.c
new file mode 100644
index 00000000000..ab98c6fec9e
--- /dev/null
+++ b/arch/arm/mach-imx/platsmp.c
@@ -0,0 +1,85 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc.
+ * Copyright 2011 Linaro Ltd.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <asm/page.h>
+#include <asm/smp_scu.h>
+#include <asm/hardware/gic.h>
+#include <asm/mach/map.h>
+#include <mach/common.h>
+#include <mach/hardware.h>
+
+static void __iomem *scu_base;
+
+static struct map_desc scu_io_desc __initdata = {
+        /* .virtual and .pfn are run-time assigned */
+        .length         = SZ_4K,
+        .type           = MT_DEVICE,
+};
+
+void __init imx_scu_map_io(void)
+{
+        unsigned long base;
+
+        /* Get SCU base */
+        asm("mrc p15, 4, %0, c15, c0, 0" : "=r" (base));
+
+        scu_io_desc.virtual = IMX_IO_P2V(base);
+        scu_io_desc.pfn = __phys_to_pfn(base);
+        iotable_init(&scu_io_desc, 1);
+
+        scu_base = IMX_IO_ADDRESS(base);
+}
+
+void __cpuinit platform_secondary_init(unsigned int cpu)
+{
+        /*
+         * if any interrupts are already enabled for the primary
+         * core (e.g. timer irq), then they will not have been enabled
+         * for us: do so
+         */
+        gic_secondary_init(0);
+}
+
+int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+        imx_set_cpu_jump(cpu, v7_secondary_startup);
+        imx_enable_cpu(cpu, true);
+        return 0;
+}
+
+/*
+ * Initialise the CPU possible map early - this describes the CPUs
+ * which may be present or become present in the system.
+ */
+void __init smp_init_cpus(void)
+{
+        int i, ncores;
+
+        ncores = scu_get_core_count(scu_base);
+
+        for (i = 0; i < ncores; i++)
+                set_cpu_possible(i, true);
+
+        set_smp_cross_call(gic_raise_softirq);
+}
+
+void imx_smp_prepare(void)
+{
+        scu_enable(scu_base);
+}
+
+void __init platform_smp_prepare_cpus(unsigned int max_cpus)
+{
+        imx_smp_prepare();
+}
diff --git a/arch/arm/plat-mxc/include/mach/common.h b/arch/arm/plat-mxc/include/mach/common.h
index c2258374488..6340df2284d 100644
--- a/arch/arm/plat-mxc/include/mach/common.h
+++ b/arch/arm/plat-mxc/include/mach/common.h
@@ -99,4 +99,9 @@ void gic_handle_irq(struct pt_regs *);
 #define imx53_handle_irq tzic_handle_irq
 #define imx6q_handle_irq gic_handle_irq
 
+extern void imx_enable_cpu(int cpu, bool enable);
+extern void imx_set_cpu_jump(int cpu, void *jump_addr);
+#ifdef CONFIG_SMP
+extern void v7_secondary_startup(void);
+#endif
 #endif