cregit-Linux how code gets into the kernel

Release 4.14 arch/sh/kernel/cpu/sh4a/smp-shx3.c

/*
 * SH-X3 SMP
 *
 *  Copyright (C) 2007 - 2010  Paul Mundt
 *  Copyright (C) 2007  Magnus Damm
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/cpumask.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/cpu.h>
#include <asm/sections.h>


#define STBCR_REG(phys_id) (0xfe400004 | (phys_id << 12))

#define RESET_REG(phys_id) (0xfe400008 | (phys_id << 12))


#define STBCR_MSTP	0x00000001

#define STBCR_RESET	0x00000002

#define STBCR_SLEEP	0x00000004

#define STBCR_LTSLP	0x80000000


static irqreturn_t ipi_interrupt_handler(int irq, void *arg) { unsigned int message = (unsigned int)(long)arg; unsigned int cpu = hard_smp_processor_id(); unsigned int offs = 4 * cpu; unsigned int x; x = __raw_readl(0xfe410070 + offs); /* C0INITICI..CnINTICI */ x &= (1 << (message << 2)); __raw_writel(x, 0xfe410080 + offs); /* C0INTICICLR..CnINTICICLR */ smp_message_recv(message); return IRQ_HANDLED; }

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Paul Mundt85100.00%2100.00%
Total85100.00%2100.00%


static void shx3_smp_setup(void) { unsigned int cpu = 0; int i, num; init_cpu_possible(cpumask_of(cpu)); /* Enable light sleep for the boot CPU */ __raw_writel(__raw_readl(STBCR_REG(cpu)) | STBCR_LTSLP, STBCR_REG(cpu)); __cpu_number_map[0] = 0; __cpu_logical_map[0] = 0; /* * Do this stupidly for now.. we don't have an easy way to probe * for the total number of cores. */ for (i = 1, num = 0; i < NR_CPUS; i++) { set_cpu_possible(i, true); __cpu_number_map[i] = ++num; __cpu_logical_map[num] = i; } printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num); }

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Paul Mundt10595.45%375.00%
Rusty Russell54.55%125.00%
Total110100.00%4100.00%


static void shx3_prepare_cpus(unsigned int max_cpus) { int i; BUILD_BUG_ON(SMP_MSG_NR >= 8); for (i = 0; i < SMP_MSG_NR; i++) request_irq(104 + i, ipi_interrupt_handler, IRQF_PERCPU, "IPI", (void *)(long)i); for (i = 0; i < max_cpus; i++) set_cpu_present(i, true); }

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Paul Mundt75100.00%5100.00%
Total75100.00%5100.00%


static void shx3_start_cpu(unsigned int cpu, unsigned long entry_point) { if (__in_29bit_mode()) __raw_writel(entry_point, RESET_REG(cpu)); else __raw_writel(virt_to_phys(entry_point), RESET_REG(cpu)); if (!(__raw_readl(STBCR_REG(cpu)) & STBCR_MSTP)) __raw_writel(STBCR_MSTP, STBCR_REG(cpu)); while (!(__raw_readl(STBCR_REG(cpu)) & STBCR_MSTP)) cpu_relax(); /* Start up secondary processor by sending a reset */ __raw_writel(STBCR_RESET | STBCR_LTSLP, STBCR_REG(cpu)); }

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Paul Mundt99100.00%5100.00%
Total99100.00%5100.00%


static unsigned int shx3_smp_processor_id(void) { return __raw_readl(0xff000048); /* CPIDR */ }

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Paul Mundt16100.00%3100.00%
Total16100.00%3100.00%


static void shx3_send_ipi(unsigned int cpu, unsigned int message) { unsigned long addr = 0xfe410070 + (cpu * 4); BUG_ON(cpu >= 4); __raw_writel(1 << (message << 2), addr); /* C0INTICI..CnINTICI */ }

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Paul Mundt47100.00%3100.00%
Total47100.00%3100.00%


static void shx3_update_boot_vector(unsigned int cpu) { __raw_writel(STBCR_MSTP, STBCR_REG(cpu)); while (!(__raw_readl(STBCR_REG(cpu)) & STBCR_MSTP)) cpu_relax(); __raw_writel(STBCR_RESET, STBCR_REG(cpu)); }

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Paul Mundt48100.00%1100.00%
Total48100.00%1100.00%


static int shx3_cpu_prepare(unsigned int cpu) { shx3_update_boot_vector(cpu); return 0; }

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Paul Mundt1583.33%150.00%
Sebastian Andrzej Siewior316.67%150.00%
Total18100.00%2100.00%


static int register_shx3_cpu_notifier(void) { cpuhp_setup_state_nocalls(CPUHP_SH_SH3X_PREPARE, "sh/shx3:prepare", shx3_cpu_prepare, NULL); return 0; }

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Paul Mundt1463.64%150.00%
Sebastian Andrzej Siewior836.36%150.00%
Total22100.00%2100.00%

late_initcall(register_shx3_cpu_notifier); struct plat_smp_ops shx3_smp_ops = { .smp_setup = shx3_smp_setup, .prepare_cpus = shx3_prepare_cpus, .start_cpu = shx3_start_cpu, .smp_processor_id = shx3_smp_processor_id, .send_ipi = shx3_send_ipi, .cpu_die = native_cpu_die, .cpu_disable = native_cpu_disable, .play_dead = native_play_dead, };

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Paul Mundt61697.47%981.82%
Sebastian Andrzej Siewior111.74%19.09%
Rusty Russell50.79%19.09%
Total632100.00%11100.00%
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