https://github.com/torvalds/linux
Tip revision: 7d2a07b769330c34b4deabeed939325c77a7ec2f authored by Linus Torvalds on 29 August 2021, 22:04:50 UTC
Linux 5.14
Linux 5.14
Tip revision: 7d2a07b
smp.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2001,2002,2004 Broadcom Corporation
*/
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/smp.h>
#include <linux/kernel_stat.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <asm/mmu_context.h>
#include <asm/io.h>
#include <asm/fw/cfe/cfe_api.h>
#include <asm/sibyte/sb1250.h>
#include <asm/sibyte/bcm1480_regs.h>
#include <asm/sibyte/bcm1480_int.h>
/*
* These are routines for dealing with the bcm1480 smp capabilities
* independent of board/firmware
*/
static void *mailbox_0_set_regs[] = {
IOADDR(A_BCM1480_IMR_CPU0_BASE + R_BCM1480_IMR_MAILBOX_0_SET_CPU),
IOADDR(A_BCM1480_IMR_CPU1_BASE + R_BCM1480_IMR_MAILBOX_0_SET_CPU),
IOADDR(A_BCM1480_IMR_CPU2_BASE + R_BCM1480_IMR_MAILBOX_0_SET_CPU),
IOADDR(A_BCM1480_IMR_CPU3_BASE + R_BCM1480_IMR_MAILBOX_0_SET_CPU),
};
static void *mailbox_0_clear_regs[] = {
IOADDR(A_BCM1480_IMR_CPU0_BASE + R_BCM1480_IMR_MAILBOX_0_CLR_CPU),
IOADDR(A_BCM1480_IMR_CPU1_BASE + R_BCM1480_IMR_MAILBOX_0_CLR_CPU),
IOADDR(A_BCM1480_IMR_CPU2_BASE + R_BCM1480_IMR_MAILBOX_0_CLR_CPU),
IOADDR(A_BCM1480_IMR_CPU3_BASE + R_BCM1480_IMR_MAILBOX_0_CLR_CPU),
};
static void *mailbox_0_regs[] = {
IOADDR(A_BCM1480_IMR_CPU0_BASE + R_BCM1480_IMR_MAILBOX_0_CPU),
IOADDR(A_BCM1480_IMR_CPU1_BASE + R_BCM1480_IMR_MAILBOX_0_CPU),
IOADDR(A_BCM1480_IMR_CPU2_BASE + R_BCM1480_IMR_MAILBOX_0_CPU),
IOADDR(A_BCM1480_IMR_CPU3_BASE + R_BCM1480_IMR_MAILBOX_0_CPU),
};
/*
* SMP init and finish on secondary CPUs
*/
void bcm1480_smp_init(void)
{
unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
STATUSF_IP1 | STATUSF_IP0;
/* Set interrupt mask, but don't enable */
change_c0_status(ST0_IM, imask);
}
/*
* These are routines for dealing with the sb1250 smp capabilities
* independent of board/firmware
*/
/*
* Simple enough; everything is set up, so just poke the appropriate mailbox
* register, and we should be set
*/
static void bcm1480_send_ipi_single(int cpu, unsigned int action)
{
__raw_writeq((((u64)action)<< 48), mailbox_0_set_regs[cpu]);
}
static void bcm1480_send_ipi_mask(const struct cpumask *mask,
unsigned int action)
{
unsigned int i;
for_each_cpu(i, mask)
bcm1480_send_ipi_single(i, action);
}
/*
* Code to run on secondary just after probing the CPU
*/
static void bcm1480_init_secondary(void)
{
extern void bcm1480_smp_init(void);
bcm1480_smp_init();
}
/*
* Do any tidying up before marking online and running the idle
* loop
*/
static void bcm1480_smp_finish(void)
{
extern void sb1480_clockevent_init(void);
sb1480_clockevent_init();
local_irq_enable();
}
/*
* Setup the PC, SP, and GP of a secondary processor and start it
* running!
*/
static int bcm1480_boot_secondary(int cpu, struct task_struct *idle)
{
int retval;
retval = cfe_cpu_start(cpu_logical_map(cpu), &smp_bootstrap,
__KSTK_TOS(idle),
(unsigned long)task_thread_info(idle), 0);
if (retval != 0)
printk("cfe_start_cpu(%i) returned %i\n" , cpu, retval);
return retval;
}
/*
* Use CFE to find out how many CPUs are available, setting up
* cpu_possible_mask and the logical/physical mappings.
* XXXKW will the boot CPU ever not be physical 0?
*
* Common setup before any secondaries are started
*/
static void __init bcm1480_smp_setup(void)
{
int i, num;
init_cpu_possible(cpumask_of(0));
__cpu_number_map[0] = 0;
__cpu_logical_map[0] = 0;
for (i = 1, num = 0; i < NR_CPUS; i++) {
if (cfe_cpu_stop(i) == 0) {
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);
}
static void __init bcm1480_prepare_cpus(unsigned int max_cpus)
{
}
const struct plat_smp_ops bcm1480_smp_ops = {
.send_ipi_single = bcm1480_send_ipi_single,
.send_ipi_mask = bcm1480_send_ipi_mask,
.init_secondary = bcm1480_init_secondary,
.smp_finish = bcm1480_smp_finish,
.boot_secondary = bcm1480_boot_secondary,
.smp_setup = bcm1480_smp_setup,
.prepare_cpus = bcm1480_prepare_cpus,
};
void bcm1480_mailbox_interrupt(void)
{
int cpu = smp_processor_id();
int irq = K_BCM1480_INT_MBOX_0_0;
unsigned int action;
kstat_incr_irq_this_cpu(irq);
/* Load the mailbox register to figure out what we're supposed to do */
action = (__raw_readq(mailbox_0_regs[cpu]) >> 48) & 0xffff;
/* Clear the mailbox to clear the interrupt */
__raw_writeq(((u64)action)<<48, mailbox_0_clear_regs[cpu]);
if (action & SMP_RESCHEDULE_YOURSELF)
scheduler_ipi();
if (action & SMP_CALL_FUNCTION) {
irq_enter();
generic_smp_call_function_interrupt();
irq_exit();
}
}