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 <cpu_func.h>
8 #include <dm.h>
9 #include <asm/barrier.h>
10 #include <asm/global_data.h>
11 #include <asm/smp.h>
12 #include <linux/printk.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_enabled(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 #if !CONFIG_IS_ENABLED(XIP)
49 #ifdef CONFIG_AVAILABLE_HARTS
50 /* skip if hart is not available */
51 if (!(gd->arch.available_harts & (1 << reg)))
52 continue;
53 #endif
54 #endif
55
56 gd->arch.ipi[reg].addr = ipi->addr;
57 gd->arch.ipi[reg].arg0 = ipi->arg0;
58 gd->arch.ipi[reg].arg1 = ipi->arg1;
59
60 /*
61 * Ensure valid only becomes set when the IPI parameters are
62 * set. An IPI may already be pending on other harts, so we
63 * need a way to signal that the IPI device has been
64 * initialized, and that it is ok to call the function.
65 */
66 __smp_store_release(&gd->arch.ipi[reg].valid, 1);
67
68 ret = riscv_send_ipi(reg);
69 if (ret) {
70 pr_err("Cannot send IPI to hart %d\n", reg);
71 return ret;
72 }
73
74 if (wait) {
75 pending = 1;
76 while (pending) {
77 ret = riscv_get_ipi(reg, &pending);
78 if (ret)
79 return ret;
80 }
81 }
82 }
83
84 return 0;
85 }
86
handle_ipi(ulong hart)87 void handle_ipi(ulong hart)
88 {
89 int ret;
90 void (*smp_function)(ulong hart, ulong arg0, ulong arg1);
91
92 if (hart >= CONFIG_NR_CPUS)
93 return;
94
95 /*
96 * If valid is not set, then U-Boot has not requested the IPI. The
97 * IPI device may not be initialized, so all we can do is wait for
98 * U-Boot to initialize it and send an IPI
99 */
100 if (!__smp_load_acquire(&gd->arch.ipi[hart].valid))
101 return;
102
103 smp_function = (void (*)(ulong, ulong, ulong))gd->arch.ipi[hart].addr;
104 invalidate_icache_all();
105
106 /*
107 * Clear the IPI to acknowledge the request before jumping to the
108 * requested function.
109 */
110 ret = riscv_clear_ipi(hart);
111 if (ret) {
112 pr_err("Cannot clear IPI of hart %ld (error %d)\n", hart, ret);
113 return;
114 }
115
116 smp_function(hart, gd->arch.ipi[hart].arg0, gd->arch.ipi[hart].arg1);
117 }
118
smp_call_function(ulong addr,ulong arg0,ulong arg1,int wait)119 int smp_call_function(ulong addr, ulong arg0, ulong arg1, int wait)
120 {
121 struct ipi_data ipi = {
122 .addr = addr,
123 .arg0 = arg0,
124 .arg1 = arg1,
125 };
126
127 return send_ipi_many(&ipi, wait);
128 }
129