1 /*
2 * Copyright 2020, Data61, CSIRO (ABN 41 687 119 230)
3 *
4 * SPDX-License-Identifier: GPL-2.0-only
5 */
6
7 #include <config.h>
8 #include <arch/machine.h>
9 #include <arch/kernel/boot_sys.h>
10 #include <arch/kernel/smp_sys.h>
11 #include <smp/lock.h>
12
13 #ifdef ENABLE_SMP_SUPPORT
14
15 /* Index of next AP to boot, BSP has index zero */
16 BOOT_DATA VISIBLE
17 volatile word_t smp_aps_index = 1;
18
19 #ifdef CONFIG_USE_LOGICAL_IDS
update_logical_id_mappings(void)20 BOOT_CODE static void update_logical_id_mappings(void)
21 {
22 cpu_mapping.index_to_logical_id[getCurrentCPUIndex()] = apic_get_logical_id();
23
24 for (int i = 0; i < smp_aps_index; i++) {
25 if (apic_get_cluster(cpu_mapping.index_to_logical_id[getCurrentCPUIndex()]) ==
26 apic_get_cluster(cpu_mapping.index_to_logical_id[i])) {
27
28 cpu_mapping.other_indexes_in_cluster[getCurrentCPUIndex()] |= BIT(i);
29 cpu_mapping.other_indexes_in_cluster[i] |= BIT(getCurrentCPUIndex());
30 }
31 }
32 }
33 #endif /* CONFIG_USE_LOGICAL_IDS */
34
start_cpu(cpu_id_t cpu_id,paddr_t boot_fun_paddr)35 BOOT_CODE static void start_cpu(cpu_id_t cpu_id, paddr_t boot_fun_paddr)
36 {
37 /* memory fence needed before starting the other CPU */
38 x86_mfence();
39
40 /* starting the other CPU */
41 apic_send_init_ipi(cpu_id);
42 apic_send_startup_ipi(cpu_id, boot_fun_paddr);
43 }
44
start_boot_aps(void)45 BOOT_CODE void start_boot_aps(void)
46 {
47 /* update cpu mapping for BSP, cpus[0] is always assumed to be BSP */
48 cpu_mapping.index_to_cpu_id[getCurrentCPUIndex()] = boot_state.cpus[0];
49 #ifdef CONFIG_USE_LOGICAL_IDS
50 cpu_mapping.index_to_logical_id[getCurrentCPUIndex()] = apic_get_logical_id();
51 #endif /* CONFIG_USE_LOGICAL_IDS */
52
53 /* startup APs one at a time as we use shared kernel boot stack */
54 while (smp_aps_index < boot_state.num_cpus) {
55 word_t current_ap_index = smp_aps_index;
56
57 printf("Starting node #%lu with APIC ID %lu \n",
58 current_ap_index, boot_state.cpus[current_ap_index]);
59
60 /* update cpu mapping for APs, store APIC ID of the next booting AP
61 * as APIC ID are not continoius e.g. 0,2,1,3 for 4 cores with hyperthreading
62 * we need to store a mapping to translate the index to real APIC ID */
63 cpu_mapping.index_to_cpu_id[current_ap_index] = boot_state.cpus[current_ap_index];
64 start_cpu(boot_state.cpus[current_ap_index], BOOT_NODE_PADDR);
65
66 /* wait for current AP to boot up */
67 while (smp_aps_index == current_ap_index);
68 }
69 }
70
copy_boot_code_aps(uint32_t mem_lower)71 BOOT_CODE bool_t copy_boot_code_aps(uint32_t mem_lower)
72 {
73 assert(boot_cpu_end - boot_cpu_start < 0x400);
74
75 /* Ensure that our boot code fits in the memory hole we want to use, and check this region
76 * is free according to multiboot. As boot_cpu_end and boot_cpu_start are link time
77 * symbols (and not compile time) this cannot be a compile time check */
78 word_t boot_size = (word_t)(boot_cpu_end - boot_cpu_start);
79 word_t boot_node_top = BOOT_NODE_PADDR + boot_size;
80 word_t mem_lower_bytes = mem_lower << 10;
81 if (boot_node_top > BOOT_NODE_MAX_PADDR) {
82 printf("AP boot code does not fit in chosen memory hole. Can be at most %lu, is %lu\n",
83 (word_t)(BOOT_NODE_MAX_PADDR - BOOT_NODE_PADDR), boot_size);
84 return false;
85 }
86 if (mem_lower_bytes < boot_node_top) {
87 printf("Need lower physical memory up to %lu to be free. Multiboot reports only up to %lu\n",
88 boot_node_top, mem_lower_bytes);
89 return false;
90 }
91
92 /* copy CPU bootup code to lower memory */
93 memcpy((void *)BOOT_NODE_PADDR, boot_cpu_start, boot_size);
94 return true;
95 }
96
try_boot_node(void)97 static BOOT_CODE bool_t try_boot_node(void)
98 {
99 setCurrentVSpaceRoot(kpptr_to_paddr(X86_KERNEL_VSPACE_ROOT), 0);
100 /* Sync up the compilers view of the world here to force the PD to actually
101 * be set *right now* instead of delayed */
102 asm volatile("" ::: "memory");
103
104 /* initialise the CPU, make sure legacy interrupts are disabled */
105 if (!init_cpu(1)) {
106 return false;
107 }
108
109 #ifdef CONFIG_USE_LOGICAL_IDS
110 update_logical_id_mappings();
111 #endif /* CONFIG_USE_LOGICAL_IDS */
112 return true;
113 }
114
115 /* This is the entry function for APs. However, it is not a BOOT_CODE as
116 * there is a race between exiting this function and root task running on
117 * node #0 to possibly reallocate this memory */
boot_node(void)118 VISIBLE void boot_node(void)
119 {
120 bool_t result;
121
122 mode_init_tls(smp_aps_index);
123 result = try_boot_node();
124
125 if (!result) {
126 fail("boot_node failed for some reason :(\n");
127 }
128
129 smp_aps_index++;
130
131 /* grab BKL before leaving the kernel */
132 NODE_LOCK_SYS;
133
134 init_core_state(SchedulerAction_ChooseNewThread);
135 ARCH_NODE_STATE(x86KScurInterrupt) = int_invalid;
136 ARCH_NODE_STATE(x86KSPendingInterrupt) = int_invalid;
137
138 schedule();
139 activateThread();
140 }
141
142 #endif /* ENABLE_SMP_SUPPORT */
143