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/global_data.h>
12 #include <asm/smp.h>
13
14 DECLARE_GLOBAL_DATA_PTR;
15
send_ipi_many(struct ipi_data * ipi,int wait)16 static int send_ipi_many(struct ipi_data *ipi, int wait)
17 {
18 ofnode node, cpus;
19 u32 reg;
20 int ret, pending;
21
22 cpus = ofnode_path("/cpus");
23 if (!ofnode_valid(cpus)) {
24 pr_err("Can't find cpus node!\n");
25 return -EINVAL;
26 }
27
28 ofnode_for_each_subnode(node, cpus) {
29 /* skip if hart is marked as not available in the device tree */
30 if (!ofnode_is_available(node))
31 continue;
32
33 /* read hart ID of CPU */
34 ret = ofnode_read_u32(node, "reg", ®);
35 if (ret)
36 continue;
37
38 /* skip if it is the hart we are running on */
39 if (reg == gd->arch.boot_hart)
40 continue;
41
42 if (reg >= CONFIG_NR_CPUS) {
43 pr_err("Hart ID %d is out of range, increase CONFIG_NR_CPUS\n",
44 reg);
45 continue;
46 }
47
48 #ifndef CONFIG_XIP
49 /* skip if hart is not available */
50 if (!(gd->arch.available_harts & (1 << reg)))
51 continue;
52 #endif
53
54 gd->arch.ipi[reg].addr = ipi->addr;
55 gd->arch.ipi[reg].arg0 = ipi->arg0;
56 gd->arch.ipi[reg].arg1 = ipi->arg1;
57
58 /*
59 * Ensure valid only becomes set when the IPI parameters are
60 * set. An IPI may already be pending on other harts, so we
61 * need a way to signal that the IPI device has been
62 * initialized, and that it is ok to call the function.
63 */
64 __smp_store_release(&gd->arch.ipi[reg].valid, 1);
65
66 ret = riscv_send_ipi(reg);
67 if (ret) {
68 pr_err("Cannot send IPI to hart %d\n", reg);
69 return ret;
70 }
71
72 if (wait) {
73 pending = 1;
74 while (pending) {
75 ret = riscv_get_ipi(reg, &pending);
76 if (ret)
77 return ret;
78 }
79 }
80 }
81
82 return 0;
83 }
84
handle_ipi(ulong hart)85 void handle_ipi(ulong hart)
86 {
87 int ret;
88 void (*smp_function)(ulong hart, ulong arg0, ulong arg1);
89
90 if (hart >= CONFIG_NR_CPUS)
91 return;
92
93 /*
94 * If valid is not set, then U-Boot has not requested the IPI. The
95 * IPI device may not be initialized, so all we can do is wait for
96 * U-Boot to initialize it and send an IPI
97 */
98 if (!__smp_load_acquire(&gd->arch.ipi[hart].valid))
99 return;
100
101 smp_function = (void (*)(ulong, ulong, ulong))gd->arch.ipi[hart].addr;
102 invalidate_icache_all();
103
104 /*
105 * Clear the IPI to acknowledge the request before jumping to the
106 * requested function.
107 */
108 ret = riscv_clear_ipi(hart);
109 if (ret) {
110 pr_err("Cannot clear IPI of hart %ld (error %d)\n", hart, ret);
111 return;
112 }
113
114 smp_function(hart, gd->arch.ipi[hart].arg0, gd->arch.ipi[hart].arg1);
115 }
116
smp_call_function(ulong addr,ulong arg0,ulong arg1,int wait)117 int smp_call_function(ulong addr, ulong arg0, ulong arg1, int wait)
118 {
119 struct ipi_data ipi = {
120 .addr = addr,
121 .arg0 = arg0,
122 .arg1 = arg1,
123 };
124
125 return send_ipi_many(&ipi, wait);
126 }
127