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The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.
After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.
Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
and are flagged as __cpuinit -- so if we remove the __cpuinit from
the arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
related content into no-ops as early as possible, since that will get
rid of these warnings. In any case, they are temporary and harmless.
This removes all the ARM uses of the __cpuinit macros from C code,
and all __CPUINIT from assembly code. It also had two ".previous"
section statements that were paired off against __CPUINIT
(aka .section ".cpuinit.text") that also get removed here.
[1] https://lkml.org/lkml/2013/5/20/589
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
103 lines
2.7 KiB
C
103 lines
2.7 KiB
C
/*
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* Copyright 2010-2011 Calxeda, Inc.
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* Copyright 2012 Pavel Machek <pavel@denx.de>
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* Based on platsmp.c, Copyright (C) 2002 ARM Ltd.
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* Copyright (C) 2012 Altera Corporation
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/smp.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <asm/cacheflush.h>
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#include <asm/smp_scu.h>
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#include <asm/smp_plat.h>
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#include "core.h"
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static int socfpga_boot_secondary(unsigned int cpu, struct task_struct *idle)
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{
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int trampoline_size = &secondary_trampoline_end - &secondary_trampoline;
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if (cpu1start_addr) {
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memcpy(phys_to_virt(0), &secondary_trampoline, trampoline_size);
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__raw_writel(virt_to_phys(socfpga_secondary_startup),
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(sys_manager_base_addr + (cpu1start_addr & 0x000000ff)));
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flush_cache_all();
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smp_wmb();
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outer_clean_range(0, trampoline_size);
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/* This will release CPU #1 out of reset.*/
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__raw_writel(0, rst_manager_base_addr + 0x10);
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}
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return 0;
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}
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/*
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* Initialise the CPU possible map early - this describes the CPUs
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* which may be present or become present in the system.
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*/
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static void __init socfpga_smp_init_cpus(void)
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{
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unsigned int i, ncores;
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ncores = scu_get_core_count(socfpga_scu_base_addr);
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for (i = 0; i < ncores; i++)
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set_cpu_possible(i, true);
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/* sanity check */
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if (ncores > num_possible_cpus()) {
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pr_warn("socfpga: no. of cores (%d) greater than configured"
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"maximum of %d - clipping\n", ncores, num_possible_cpus());
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ncores = num_possible_cpus();
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}
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for (i = 0; i < ncores; i++)
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set_cpu_possible(i, true);
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}
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static void __init socfpga_smp_prepare_cpus(unsigned int max_cpus)
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{
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scu_enable(socfpga_scu_base_addr);
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}
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/*
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* platform-specific code to shutdown a CPU
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*
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* Called with IRQs disabled
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*/
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static void socfpga_cpu_die(unsigned int cpu)
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{
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cpu_do_idle();
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/* We should have never returned from idle */
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panic("cpu %d unexpectedly exit from shutdown\n", cpu);
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}
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struct smp_operations socfpga_smp_ops __initdata = {
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.smp_init_cpus = socfpga_smp_init_cpus,
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.smp_prepare_cpus = socfpga_smp_prepare_cpus,
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.smp_boot_secondary = socfpga_boot_secondary,
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#ifdef CONFIG_HOTPLUG_CPU
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.cpu_die = socfpga_cpu_die,
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#endif
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};
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