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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>
132 lines
3.1 KiB
C
132 lines
3.1 KiB
C
/*
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* Symmetric Multi Processing (SMP) support for Armada XP
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*
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* Copyright (C) 2012 Marvell
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*
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* Lior Amsalem <alior@marvell.com>
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* Yehuda Yitschak <yehuday@marvell.com>
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* Gregory CLEMENT <gregory.clement@free-electrons.com>
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* Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*
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* The Armada XP SoC has 4 ARMv7 PJ4B CPUs running in full HW coherency
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* This file implements the routines for preparing the SMP infrastructure
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* and waking up the secondary CPUs
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*/
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#include <linux/init.h>
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#include <linux/smp.h>
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#include <linux/clk.h>
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#include <linux/of.h>
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#include <linux/mbus.h>
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#include <asm/cacheflush.h>
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#include <asm/smp_plat.h>
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#include "common.h"
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#include "armada-370-xp.h"
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#include "pmsu.h"
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#include "coherency.h"
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void __init set_secondary_cpus_clock(void)
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{
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int thiscpu;
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unsigned long rate;
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struct clk *cpu_clk = NULL;
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struct device_node *np = NULL;
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thiscpu = smp_processor_id();
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for_each_node_by_type(np, "cpu") {
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int err;
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int cpu;
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err = of_property_read_u32(np, "reg", &cpu);
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if (WARN_ON(err))
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return;
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if (cpu == thiscpu) {
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cpu_clk = of_clk_get(np, 0);
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break;
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}
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}
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if (WARN_ON(IS_ERR(cpu_clk)))
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return;
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clk_prepare_enable(cpu_clk);
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rate = clk_get_rate(cpu_clk);
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/* set all the other CPU clk to the same rate than the boot CPU */
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for_each_node_by_type(np, "cpu") {
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int err;
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int cpu;
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err = of_property_read_u32(np, "reg", &cpu);
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if (WARN_ON(err))
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return;
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if (cpu != thiscpu) {
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cpu_clk = of_clk_get(np, 0);
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clk_set_rate(cpu_clk, rate);
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}
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}
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}
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static void armada_xp_secondary_init(unsigned int cpu)
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{
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armada_xp_mpic_smp_cpu_init();
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}
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static int armada_xp_boot_secondary(unsigned int cpu, struct task_struct *idle)
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{
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pr_info("Booting CPU %d\n", cpu);
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armada_xp_boot_cpu(cpu, armada_xp_secondary_startup);
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return 0;
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}
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static void __init armada_xp_smp_init_cpus(void)
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{
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struct device_node *np;
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unsigned int i, ncores;
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np = of_find_node_by_name(NULL, "cpus");
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if (!np)
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panic("No 'cpus' node found\n");
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ncores = of_get_child_count(np);
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if (ncores == 0 || ncores > ARMADA_XP_MAX_CPUS)
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panic("Invalid number of CPUs in DT\n");
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/* Limit possible CPUs to defconfig */
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if (ncores > nr_cpu_ids) {
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pr_warn("SMP: %d CPUs physically present. Only %d configured.",
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ncores, nr_cpu_ids);
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pr_warn("Clipping CPU count to %d\n", nr_cpu_ids);
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ncores = nr_cpu_ids;
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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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set_smp_cross_call(armada_mpic_send_doorbell);
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}
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void __init armada_xp_smp_prepare_cpus(unsigned int max_cpus)
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{
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set_secondary_cpus_clock();
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flush_cache_all();
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set_cpu_coherent(cpu_logical_map(smp_processor_id()), 0);
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mvebu_mbus_add_window("bootrom", 0xfff00000, SZ_1M);
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}
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struct smp_operations armada_xp_smp_ops __initdata = {
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.smp_init_cpus = armada_xp_smp_init_cpus,
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.smp_prepare_cpus = armada_xp_smp_prepare_cpus,
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.smp_secondary_init = armada_xp_secondary_init,
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.smp_boot_secondary = armada_xp_boot_secondary,
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#ifdef CONFIG_HOTPLUG_CPU
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.cpu_die = armada_xp_cpu_die,
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#endif
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};
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