[PATCH v4 5/7] arm/imx6q: add smp and cpu hotplug support
Shawn Guo
shawn.guo at linaro.org
Wed Sep 28 05:06:46 EDT 2011
It adds smp and cpu hotplug support for imx6q.
Signed-off-by: Shawn Guo <shawn.guo at linaro.org>
---
arch/arm/mach-imx/Kconfig | 1 +
arch/arm/mach-imx/Makefile | 5 ++
arch/arm/mach-imx/head-v7.S | 71 ++++++++++++++++++++++++++
arch/arm/mach-imx/hotplug.c | 44 ++++++++++++++++
arch/arm/mach-imx/localtimer.c | 35 +++++++++++++
arch/arm/mach-imx/platsmp.c | 85 +++++++++++++++++++++++++++++++
arch/arm/plat-mxc/include/mach/common.h | 5 ++
7 files changed, 246 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/mach-imx/head-v7.S
create mode 100644 arch/arm/mach-imx/hotplug.c
create mode 100644 arch/arm/mach-imx/localtimer.c
create mode 100644 arch/arm/mach-imx/platsmp.c
diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
index 7555410..d52fe3d 100644
--- a/arch/arm/mach-imx/Kconfig
+++ b/arch/arm/mach-imx/Kconfig
@@ -610,6 +610,7 @@ config SOC_IMX6Q
bool "i.MX6 Quad support"
select ARM_GIC
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 c71e3c5..67aba68 100644
--- a/arch/arm/mach-imx/Makefile
+++ b/arch/arm/mach-imx/Makefile
@@ -66,4 +66,9 @@ 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 0000000..ede908b
--- /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 0000000..89493ab
--- /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 0000000..3a16351
--- /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 0000000..ab98c6f
--- /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 988fa9a..855c214 100644
--- a/arch/arm/plat-mxc/include/mach/common.h
+++ b/arch/arm/plat-mxc/include/mach/common.h
@@ -88,4 +88,9 @@ 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
--
1.7.4.1
More information about the linux-arm-kernel
mailing list