arch/riscv/lib/smp.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2019 Fraunhofer AISEC,
   4  * Lukas Auer <lukas.auer@aisec.fraunhofer.de>
   5  */
   6
   7 #include <common.h>
   8 #include <cpu_func.h>
   9 #include <dm.h>
  10 #include <asm/barrier.h>
  11 #include <asm/smp.h>
  12
  13 DECLARE_GLOBAL_DATA_PTR;
  14
  15 static int send_ipi_many(struct ipi_data *ipi, int wait)
  16 {
  17         ofnode node, cpus;
  18         u32 reg;
  19         int ret, pending;
  20
  21         cpus = ofnode_path("/cpus");
  22         if (!ofnode_valid(cpus)) {
  23                 pr_err("Can't find cpus node!\n");
  24                 return -EINVAL;
  25         }
  26
  27         ofnode_for_each_subnode(node, cpus) {
  28                 /* skip if hart is marked as not available in the device tree */
  29                 if (!ofnode_is_available(node))
  30                         continue;
  31
  32                 /* read hart ID of CPU */
  33                 ret = ofnode_read_u32(node, "reg", &reg);
  34                 if (ret)
  35                         continue;
  36
  37                 /* skip if it is the hart we are running on */
  38                 if (reg == gd->arch.boot_hart)
  39                         continue;
  40
  41                 if (reg >= CONFIG_NR_CPUS) {
  42                         pr_err("Hart ID %d is out of range, increase CONFIG_NR_CPUS\n",
  43                                reg);
  44                         continue;
  45                 }
  46
  47 #ifndef CONFIG_XIP
  48                 /* skip if hart is not available */
  49                 if (!(gd->arch.available_harts & (1 << reg)))
  50                         continue;
  51 #endif
  52
  53                 gd->arch.ipi[reg].addr = ipi->addr;
  54                 gd->arch.ipi[reg].arg0 = ipi->arg0;
  55                 gd->arch.ipi[reg].arg1 = ipi->arg1;
  56
  57                 ret = riscv_send_ipi(reg);
  58                 if (ret) {
  59                         pr_err("Cannot send IPI to hart %d\n", reg);
  60                         return ret;
  61                 }
  62
  63                 if (wait) {
  64                         pending = 1;
  65                         while (pending) {
  66                                 ret = riscv_get_ipi(reg, &pending);
  67                                 if (ret)
  68                                         return ret;
  69                         }
  70                 }
  71         }
  72
  73         return 0;
  74 }
  75
  76 void handle_ipi(ulong hart)
  77 {
  78         int ret;
  79         void (*smp_function)(ulong hart, ulong arg0, ulong arg1);
  80
  81         if (hart >= CONFIG_NR_CPUS)
  82                 return;
  83
  84         __smp_mb();
  85
  86         smp_function = (void (*)(ulong, ulong, ulong))gd->arch.ipi[hart].addr;
  87         invalidate_icache_all();
  88
  89         /*
  90          * Clear the IPI to acknowledge the request before jumping to the
  91          * requested function.
  92          */
  93         ret = riscv_clear_ipi(hart);
  94         if (ret) {
  95                 pr_err("Cannot clear IPI of hart %ld (error %d)\n", hart, ret);
  96                 return;
  97         }
  98
  99         smp_function(hart, gd->arch.ipi[hart].arg0, gd->arch.ipi[hart].arg1);
 100 }
 101
 102 int smp_call_function(ulong addr, ulong arg0, ulong arg1, int wait)
 103 {
 104         struct ipi_data ipi = {
 105                 .addr = addr,
 106                 .arg0 = arg0,
 107                 .arg1 = arg1,
 108         };
 109
 110         return send_ipi_many(&ipi, wait);
 111 }