u-boot/arch/riscv/lib/smp.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2019 Fraunhofer AISEC,
* Lukas Auer <lukas.auer@aisec.fraunhofer.de>
*/
#include <common.h>
#include <cpu_func.h>
#include <dm.h>
#include <asm/barrier.h>
#include <asm/smp.h>
DECLARE_GLOBAL_DATA_PTR;
/**
* riscv_send_ipi() - Send inter-processor interrupt (IPI)
*
* Platform code must provide this function.
*
* @hart: Hart ID of receiving hart
* @return 0 if OK, -ve on error
*/
extern int riscv_send_ipi(int hart);
/**
* riscv_clear_ipi() - Clear inter-processor interrupt (IPI)
*
* Platform code must provide this function.
*
* @hart: Hart ID of hart to be cleared
* @return 0 if OK, -ve on error
*/
extern int riscv_clear_ipi(int hart);
/**
* riscv_get_ipi() - Get status of inter-processor interrupt (IPI)
*
* Platform code must provide this function.
*
* @hart: Hart ID of hart to be checked
* @pending: Pointer to variable with result of the check,
* 1 if IPI is pending, 0 otherwise
* @return 0 if OK, -ve on error
*/
extern int riscv_get_ipi(int hart, int *pending);
static int send_ipi_many(struct ipi_data *ipi, int wait)
{
ofnode node, cpus;
u32 reg;
int ret, pending;
cpus = ofnode_path("/cpus");
if (!ofnode_valid(cpus)) {
pr_err("Can't find cpus node!\n");
return -EINVAL;
}
ofnode_for_each_subnode(node, cpus) {
/* skip if hart is marked as not available in the device tree */
if (!ofnode_is_available(node))
continue;
/* read hart ID of CPU */
ret = ofnode_read_u32(node, "reg", &reg);
if (ret)
continue;
/* skip if it is the hart we are running on */
if (reg == gd->arch.boot_hart)
continue;
if (reg >= CONFIG_NR_CPUS) {
pr_err("Hart ID %d is out of range, increase CONFIG_NR_CPUS\n",
reg);
continue;
}
#ifndef CONFIG_XIP
/* skip if hart is not available */
if (!(gd->arch.available_harts & (1 << reg)))
continue;
#endif
gd->arch.ipi[reg].addr = ipi->addr;
gd->arch.ipi[reg].arg0 = ipi->arg0;
gd->arch.ipi[reg].arg1 = ipi->arg1;
ret = riscv_send_ipi(reg);
if (ret) {
pr_err("Cannot send IPI to hart %d\n", reg);
return ret;
}
if (wait) {
pending = 1;
while (pending) {
ret = riscv_get_ipi(reg, &pending);
if (ret)
return ret;
}
}
}
return 0;
}
void handle_ipi(ulong hart)
{
int ret;
void (*smp_function)(ulong hart, ulong arg0, ulong arg1);
if (hart >= CONFIG_NR_CPUS)
return;
__smp_mb();
smp_function = (void (*)(ulong, ulong, ulong))gd->arch.ipi[hart].addr;
invalidate_icache_all();
/*
* Clear the IPI to acknowledge the request before jumping to the
* requested function.
*/
ret = riscv_clear_ipi(hart);
if (ret) {
pr_err("Cannot clear IPI of hart %ld\n", hart);
return;
}
smp_function(hart, gd->arch.ipi[hart].arg0, gd->arch.ipi[hart].arg1);
}
int smp_call_function(ulong addr, ulong arg0, ulong arg1, int wait)
{
int ret = 0;
struct ipi_data ipi;
ipi.addr = addr;
ipi.arg0 = arg0;
ipi.arg1 = arg1;
ret = send_ipi_many(&ipi, wait);
return ret;
}