This patch adds SMP platform files support for OMAP4430SDP. TI's OMAP4430
SOC is based on ARM Cortex-A9 SMP architecture. It's a dual core SOC
with GIC used for interrupt handling and SCU for cache coherency.
Signed-off-by: Santosh Shilimkar <santosh.shilim...@ti.com>
---
arch/arm/mach-omap2/omap-headsmp.S | 49 +++++++
arch/arm/mach-omap2/omap-smp.c | 238 +++++++++++++++++++++++++++++++++
arch/arm/plat-omap/include/mach/scu.h | 28 ++++
arch/arm/plat-omap/include/mach/smp.h | 56 ++++++++
4 files changed, 371 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/mach-omap2/omap-headsmp.S
create mode 100644 arch/arm/mach-omap2/omap-smp.c
create mode 100644 arch/arm/plat-omap/include/mach/scu.h
create mode 100644 arch/arm/plat-omap/include/mach/smp.h
diff --git a/arch/arm/mach-omap2/omap-headsmp.S
b/arch/arm/mach-omap2/omap-headsmp.S
new file mode 100644
index 0000000..0afe039
--- /dev/null
+++ b/arch/arm/mach-omap2/omap-headsmp.S
@@ -0,0 +1,49 @@
+/*
+ * Secondary CPU startup routine source file.
+ *
+ * Copyright (C) 2009 Texas Instruments, Inc.
+ *
+ * Author:
+ * Santosh Shilimkar <santosh.shilim...@ti.com>
+ *
+ * Interface functions needed for the SMP. This file is based on arm
+ * realview smp platform.
+ * Copyright (c) 2003 ARM Limited.
+ *
+ * This program is free software,you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+#include <linux/init.h>
+
+ __INIT
+
+/*
+ * OMAP4 specific entry point for secondary CPU to jump from ROM
+ * code. This routine also provides a holding flag into which
+ * secondary core is held until we're ready for it to initialise.
+ * The primary core will update the this flag using a hardware
+ * register AuxCoreBoot1.
+ */
+ENTRY(omap_secondary_startup)
+ mrc p15, 0, r0, c0, c0, 5
+ and r0, r0, #15
+ adr r4, 1f
+ ldmia r4, {r5, r6}
+ sub r4, r4, r5
+ add r6, r6, r4
+hold: ldr r7, [r6] @ read from AuxCoreBoot1
+ cmp r7, r0
+ bne hold
+
+ /*
+ * we've been released from the holding pen: secondary_stack
+ * should now contain the SVC stack for this core
+ */
+ b secondary_startup
+
+1: .long .
+ .long cpu_release
+
diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c
new file mode 100644
index 0000000..1d18acb
--- /dev/null
+++ b/arch/arm/mach-omap2/omap-smp.c
@@ -0,0 +1,238 @@
+/*
+ * OMAP4 SMP source file. It contains platform specific fucntions
+ * needed for the linux smp kernel.
+ *
+ * Copyright (C) 2009 Texas Instruments, Inc.
+ *
+ * Author:
+ * Santosh Shilimkar <santosh.shilim...@ti.com>
+ *
+ * Platform file needed for the OMAP4 SMP. This file is based on arm
+ * realview smp platform.
+ * * Copyright (c) 2002 ARM Limited.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/jiffies.h>
+#include <linux/smp.h>
+#include <linux/io.h>
+
+#include <asm/cacheflush.h>
+#include <mach/scu.h>
+#include <mach/hardware.h>
+#include <asm/mach-types.h>
+
+/* Registers used for communicating startup information */
+#define OMAP4_AUXCOREBOOT_REG0 (OMAP44XX_VA_WKUPGEN_BASE + 0x800)
+#define OMAP4_AUXCOREBOOT_REG1 (OMAP44XX_VA_WKUPGEN_BASE + 0x804)
+
+/* FIXME: Move to a common header file */
+extern void omap_secondary_startup(void);
+
+/*
+ * Control for which core is the next to come out of the secondary
+ * boot "Auxcontrol_register"
+ */
+int __cpuinitdata cpu_release = -1;
+
+/*
+ * Setup the SCU
+ */
+static void scu_enable(void)
+{
+ u32 scu_ctrl;
+ void __iomem *scu_base = OMAP44XX_VA_SCU_BASE;
+
+ scu_ctrl = __raw_readl(scu_base + SCU_CTRL);
+ scu_ctrl |= 1;
+ __raw_writel(scu_ctrl, scu_base + SCU_CTRL);
+}
+
+/*
+ * Use SCU config register to count number of cores
+ */
+static unsigned int __init get_core_count(void)
+{
+ unsigned int ncores;
+ void __iomem *scu_base = OMAP44XX_VA_SCU_BASE;
+
+ if (scu_base) {
+ ncores = __raw_readl(scu_base + SCU_CONFIG);
+ ncores = (ncores & 0x03) + 1;
+ } else {
+ ncores = 1;
+ }
+
+ return ncores;
+}
+
+static DEFINE_SPINLOCK(boot_lock);
+
+void __cpuinit platform_secondary_init(unsigned int cpu)
+{
+ trace_hardirqs_off();
+
+ /*
+ * 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_cpu_init(0, IO_ADDRESS(OMAP44XX_GIC_CPU_BASE));
+
+ /*
+ * Let the primary processor know we're out of the
+ * pen, then head off into the C entry point
+ */
+ cpu_release = -1;
+ smp_wmb();
+
+ /*
+ * Synchronise with the boot thread.
+ */
+ spin_lock(&boot_lock);
+ spin_unlock(&boot_lock);
+}
+
+int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+ unsigned long timeout;
+
+ /*
+ * Set synchronisation state between this boot processor
+ * and the secondary one
+ */
+ spin_lock(&boot_lock);
+
+ /*
+ * The secondary processor is waiting for an event to come out of
+ * wfe. Release it, then wait for it to flag that it has been
+ * released by resetting cpu_release.
+ *
+ * Singal the ROM code that the secondary core can be released
+ */
+ cpu_release = cpu;
+ __raw_writel(cpu, OMAP4_AUXCOREBOOT_REG1);
+ flush_cache_all();
+ /*
+ * Send a 'sev' to wake the secondary core again because
+ * ROM code will put core in WFE till the cpu_release
+ * flag is set.
+ */
+ set_event();
+ mb();
+
+ timeout = jiffies + (1 * HZ);
+ while (time_before(jiffies, timeout)) {
+ smp_rmb();
+ if (cpu_release == -1)
+ break;
+
+ udelay(10);
+ }
+
+ /*
+ * Now the secondary core is starting up let it run its
+ * calibrations, then wait for it to finish
+ */
+ spin_unlock(&boot_lock);
+
+ return cpu_release != -1 ? -ENOSYS : 0;
+}
+
+static void __init wakeup_secondary(void)
+{
+
+ /* cpu is not to be released from the hold yet */
+ cpu_release = -1;
+
+ /*
+ * write the address of secondary startup into the system-wide
+ * AuxCoreBoot0 where ROM code will jump and start executing
+ * on secondary core
+ */
+ __raw_writel(virt_to_phys(omap_secondary_startup), \
+ OMAP4_AUXCOREBOOT_REG0);
+ /*
+ * Send a 'sev' to wake the secondary core from WFE.
+ */
+ set_event();
+ mb();
+}
+
+/*
+ * 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)
+{
+ unsigned int i, ncores = get_core_count();
+
+ for (i = 0; i < ncores; i++)
+ cpu_set(i, cpu_possible_map);
+}
+
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+ unsigned int ncores = get_core_count();
+ unsigned int cpu = smp_processor_id();
+ int i;
+
+ /* sanity check */
+ if (ncores == 0) {
+ printk(KERN_ERR
+ "OMAP4: strange core count of 0? Default to 1\n");
+ ncores = 1;
+ }
+
+ if (ncores > num_possible_cpus()) {
+ printk(KERN_WARNING
+ "OMAP4: no. of cores (%d) greater than configured "
+ "maximum of %d - clipping\n",
+ ncores, num_possible_cpus());
+ ncores = num_possible_cpus();
+ }
+ smp_store_cpu_info(cpu);
+
+ /*
+ * are we trying to boot more cores than exist?
+ */
+ if (max_cpus > ncores)
+ max_cpus = ncores;
+
+#ifdef CONFIG_LOCAL_TIMERS
+ /*
+ * Enable the local timer for primary CPU. If the device is
+ * dummy (!CONFIG_LOCAL_TIMERS), it was already registers in
+ * omap_timer_init
+ */
+ local_timer_setup();
+#endif
+
+ /*
+ * Initialise the present map, which describes the set of CPUs
+ * actually populated at the present time.
+ */
+ for (i = 0; i < max_cpus; i++)
+ cpu_set(i, cpu_present_map);
+
+ /*
+ * Initialise the SCU and wake up the secondary core using
+ * wakeup_secondary().
+ */
+ if (max_cpus > 1) {
+ scu_enable();
+ /*
+ * Ensure that the data accessed by CPU0 before the SCU was
+ * initialised is visible to CPU1.
+ */
+ flush_cache_all();
+ wakeup_secondary();
+ }
+}
diff --git a/arch/arm/plat-omap/include/mach/scu.h
b/arch/arm/plat-omap/include/mach/scu.h
new file mode 100644
index 0000000..2ee6660
--- /dev/null
+++ b/arch/arm/plat-omap/include/mach/scu.h
@@ -0,0 +1,28 @@
+/*
+ * SCU regsiter header.
+ *
+ * Copyright (C) 2009 Texas Instruments, Inc.
+ *
+ *
+ * Author:
+ * Santosh Shilimkar <santosh.shilim...@ti.com>
+ *
+ * Snoop Control Unit Registers. This file is based on arm
+ * realview smp platform.
+ * Copyright (c) 2003 ARM Limited.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __OMAP_ARCH_SCU_H
+#define __OMAP_ARCH_SCU_H
+/*
+ * SCU registers
+ */
+#define SCU_CTRL 0x00
+#define SCU_CONFIG 0x04
+#define SCU_CPU_STATUS 0x08
+#define SCU_INVALIDATE 0x0c
+
+#endif
diff --git a/arch/arm/plat-omap/include/mach/smp.h
b/arch/arm/plat-omap/include/mach/smp.h
new file mode 100644
index 0000000..b6a3e67
--- /dev/null
+++ b/arch/arm/plat-omap/include/mach/smp.h
@@ -0,0 +1,56 @@
+/*
+ * OMAP4 machine specific smp.h
+ *
+ * Copyright (C) 2009 Texas Instruments, Inc.
+ *
+ * Author:
+ * Santosh Shilimkar <santosh.shilim...@ti.com>
+ *
+ * Interface functions needed for the SMP. This file is based on arm
+ * realview smp platform.
+ * Copyright (c) 2003 ARM Limited.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef OMAP_ARCH_SMP_H
+#define OMAP_ARCH_SMP_H
+
+
+#include <asm/hardware/gic.h>
+
+/*
+ * set_event() is used to wake up secondary core from wfe using sev. ROM
+ * code puts the second core into wfe(standby).
+ *
+ */
+ #define set_event() __asm__ __volatile__ ("sev" : : : "memory")
+
+/*
+ * We use Soft IRQ1 as the IPI
+ */
+static inline void smp_cross_call(cpumask_t callmap)
+{
+ gic_raise_softirq(callmap, 1);
+}
+
+/*
+ * Can be useful for WFI boot strategy.
+ */
+static inline void smp_cross_call_done(cpumask_t callmap)
+{
+}
+
+/*
+ * Read MPIDR: Multiprocessor affinity register
+ */
+#define hard_smp_processor_id() \
+ ({ \
+ unsigned int cpunum; \
+ __asm__("mrc p15, 0, %0, c0, c0, 5" \
+ : "=r" (cpunum)); \
+ cpunum &= 0x0F; \
+ })
+
+#endif
--
1.5.4.7
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