forked from Minki/linux
865d90f803
We can remove the extra code of modify_scu_cpu_psr() and use the cleaner generic ARM helper scu_power_mode(). As every CPU only deals with its own power register and scu_power_mode() operates with 8-bit accesses, we save the locking overhead too. Signed-off-by: Bastian Hecht <hechtb@gmail.com> Signed-off-by: Simon Horman <horms@verge.net.au>
117 lines
3.0 KiB
C
117 lines
3.0 KiB
C
/*
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* SMP support for Emma Mobile EV2
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*
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* Copyright (C) 2012 Renesas Solutions Corp.
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* Copyright (C) 2012 Magnus Damm
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/smp.h>
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#include <linux/spinlock.h>
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#include <linux/io.h>
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#include <linux/delay.h>
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#include <mach/common.h>
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#include <mach/emev2.h>
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#include <asm/smp_plat.h>
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#include <asm/smp_scu.h>
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#include <asm/hardware/gic.h>
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#include <asm/cacheflush.h>
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#define EMEV2_SCU_BASE 0x1e000000
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static void __iomem *scu_base;
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static unsigned int __init emev2_get_core_count(void)
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{
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if (!scu_base) {
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scu_base = ioremap(EMEV2_SCU_BASE, PAGE_SIZE);
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emev2_clock_init(); /* need ioremapped SMU */
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}
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WARN_ON_ONCE(!scu_base);
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return scu_base ? scu_get_core_count(scu_base) : 1;
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}
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static int emev2_platform_cpu_kill(unsigned int cpu)
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{
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return 0; /* not supported yet */
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}
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static int __maybe_unused emev2_cpu_kill(unsigned int cpu)
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{
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int k;
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/* this function is running on another CPU than the offline target,
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* here we need wait for shutdown code in platform_cpu_die() to
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* finish before asking SoC-specific code to power off the CPU core.
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*/
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for (k = 0; k < 1000; k++) {
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if (shmobile_cpu_is_dead(cpu))
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return emev2_platform_cpu_kill(cpu);
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mdelay(1);
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}
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return 0;
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}
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static void __cpuinit emev2_secondary_init(unsigned int cpu)
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{
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gic_secondary_init(0);
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}
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static int __cpuinit emev2_boot_secondary(unsigned int cpu, struct task_struct *idle)
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{
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cpu = cpu_logical_map(cpu);
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/* enable cache coherency */
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scu_power_mode(scu_base, 0);
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/* Tell ROM loader about our vector (in headsmp.S) */
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emev2_set_boot_vector(__pa(shmobile_secondary_vector));
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gic_raise_softirq(cpumask_of(cpu), 0);
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return 0;
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}
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static void __init emev2_smp_prepare_cpus(unsigned int max_cpus)
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{
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scu_enable(scu_base);
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/* enable cache coherency on CPU0 */
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scu_power_mode(scu_base, 0);
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}
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static void __init emev2_smp_init_cpus(void)
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{
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unsigned int ncores = emev2_get_core_count();
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shmobile_smp_init_cpus(ncores);
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}
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struct smp_operations emev2_smp_ops __initdata = {
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.smp_init_cpus = emev2_smp_init_cpus,
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.smp_prepare_cpus = emev2_smp_prepare_cpus,
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.smp_secondary_init = emev2_secondary_init,
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.smp_boot_secondary = emev2_boot_secondary,
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#ifdef CONFIG_HOTPLUG_CPU
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.cpu_kill = emev2_cpu_kill,
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.cpu_die = shmobile_cpu_die,
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.cpu_disable = shmobile_cpu_disable,
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#endif
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};
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