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1/*
2 * ARM64 ACPI Parking Protocol implementation
3 *
4 * Authors: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
5 * Mark Salter <msalter@redhat.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19#include <linux/acpi.h>
20#include <linux/types.h>
21
22#include <asm/cpu_ops.h>
23
24struct parking_protocol_mailbox {
25 __le32 cpu_id;
26 __le32 reserved;
27 __le64 entry_point;
28};
29
30struct cpu_mailbox_entry {
31 struct parking_protocol_mailbox __iomem *mailbox;
32 phys_addr_t mailbox_addr;
33 u8 version;
34 u8 gic_cpu_id;
35};
36
37static struct cpu_mailbox_entry cpu_mailbox_entries[NR_CPUS];
38
39void __init acpi_set_mailbox_entry(int cpu,
40 struct acpi_madt_generic_interrupt *p)
41{
42 struct cpu_mailbox_entry *cpu_entry = &cpu_mailbox_entries[cpu];
43
44 cpu_entry->mailbox_addr = p->parked_address;
45 cpu_entry->version = p->parking_version;
46 cpu_entry->gic_cpu_id = p->cpu_interface_number;
47}
48
49bool acpi_parking_protocol_valid(int cpu)
50{
51 struct cpu_mailbox_entry *cpu_entry = &cpu_mailbox_entries[cpu];
52
53 return cpu_entry->mailbox_addr && cpu_entry->version;
54}
55
56static int acpi_parking_protocol_cpu_init(unsigned int cpu)
57{
58 pr_debug("%s: ACPI parked addr=%llx\n", __func__,
59 cpu_mailbox_entries[cpu].mailbox_addr);
60
61 return 0;
62}
63
64static int acpi_parking_protocol_cpu_prepare(unsigned int cpu)
65{
66 return 0;
67}
68
69static int acpi_parking_protocol_cpu_boot(unsigned int cpu)
70{
71 struct cpu_mailbox_entry *cpu_entry = &cpu_mailbox_entries[cpu];
72 struct parking_protocol_mailbox __iomem *mailbox;
73 __le32 cpu_id;
74
75 /*
76 * Map mailbox memory with attribute device nGnRE (ie ioremap -
77 * this deviates from the parking protocol specifications since
78 * the mailboxes are required to be mapped nGnRnE; the attribute
79 * discrepancy is harmless insofar as the protocol specification
80 * is concerned).
81 * If the mailbox is mistakenly allocated in the linear mapping
82 * by FW ioremap will fail since the mapping will be prevented
83 * by the kernel (it clashes with the linear mapping attributes
84 * specifications).
85 */
86 mailbox = ioremap(cpu_entry->mailbox_addr, sizeof(*mailbox));
87 if (!mailbox)
88 return -EIO;
89
90 cpu_id = readl_relaxed(&mailbox->cpu_id);
91 /*
92 * Check if firmware has set-up the mailbox entry properly
93 * before kickstarting the respective cpu.
94 */
95 if (cpu_id != ~0U) {
96 iounmap(mailbox);
97 return -ENXIO;
98 }
99
100 /*
101 * stash the mailbox address mapping to use it for further FW
102 * checks in the postboot method
103 */
104 cpu_entry->mailbox = mailbox;
105
106 /*
107 * We write the entry point and cpu id as LE regardless of the
108 * native endianness of the kernel. Therefore, any boot-loaders
109 * that read this address need to convert this address to the
110 * Boot-Loader's endianness before jumping.
111 */
112 writeq_relaxed(__pa(secondary_entry), &mailbox->entry_point);
113 writel_relaxed(cpu_entry->gic_cpu_id, &mailbox->cpu_id);
114
115 arch_send_wakeup_ipi_mask(cpumask_of(cpu));
116
117 return 0;
118}
119
120static void acpi_parking_protocol_cpu_postboot(void)
121{
122 int cpu = smp_processor_id();
123 struct cpu_mailbox_entry *cpu_entry = &cpu_mailbox_entries[cpu];
124 struct parking_protocol_mailbox __iomem *mailbox = cpu_entry->mailbox;
125 __le64 entry_point;
126
127 entry_point = readl_relaxed(&mailbox->entry_point);
128 /*
129 * Check if firmware has cleared the entry_point as expected
130 * by the protocol specification.
131 */
132 WARN_ON(entry_point);
133}
134
135const struct cpu_operations acpi_parking_protocol_ops = {
136 .name = "parking-protocol",
137 .cpu_init = acpi_parking_protocol_cpu_init,
138 .cpu_prepare = acpi_parking_protocol_cpu_prepare,
139 .cpu_boot = acpi_parking_protocol_cpu_boot,
140 .cpu_postboot = acpi_parking_protocol_cpu_postboot
141};
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * ARM64 ACPI Parking Protocol implementation
4 *
5 * Authors: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
6 * Mark Salter <msalter@redhat.com>
7 */
8#include <linux/acpi.h>
9#include <linux/mm.h>
10#include <linux/types.h>
11
12#include <asm/cpu_ops.h>
13
14struct parking_protocol_mailbox {
15 __le32 cpu_id;
16 __le32 reserved;
17 __le64 entry_point;
18};
19
20struct cpu_mailbox_entry {
21 struct parking_protocol_mailbox __iomem *mailbox;
22 phys_addr_t mailbox_addr;
23 u8 version;
24 u8 gic_cpu_id;
25};
26
27static struct cpu_mailbox_entry cpu_mailbox_entries[NR_CPUS];
28
29void __init acpi_set_mailbox_entry(int cpu,
30 struct acpi_madt_generic_interrupt *p)
31{
32 struct cpu_mailbox_entry *cpu_entry = &cpu_mailbox_entries[cpu];
33
34 cpu_entry->mailbox_addr = p->parked_address;
35 cpu_entry->version = p->parking_version;
36 cpu_entry->gic_cpu_id = p->cpu_interface_number;
37}
38
39bool acpi_parking_protocol_valid(int cpu)
40{
41 struct cpu_mailbox_entry *cpu_entry = &cpu_mailbox_entries[cpu];
42
43 return cpu_entry->mailbox_addr && cpu_entry->version;
44}
45
46static int acpi_parking_protocol_cpu_init(unsigned int cpu)
47{
48 pr_debug("%s: ACPI parked addr=%llx\n", __func__,
49 cpu_mailbox_entries[cpu].mailbox_addr);
50
51 return 0;
52}
53
54static int acpi_parking_protocol_cpu_prepare(unsigned int cpu)
55{
56 return 0;
57}
58
59static int acpi_parking_protocol_cpu_boot(unsigned int cpu)
60{
61 struct cpu_mailbox_entry *cpu_entry = &cpu_mailbox_entries[cpu];
62 struct parking_protocol_mailbox __iomem *mailbox;
63 u32 cpu_id;
64
65 /*
66 * Map mailbox memory with attribute device nGnRE (ie ioremap -
67 * this deviates from the parking protocol specifications since
68 * the mailboxes are required to be mapped nGnRnE; the attribute
69 * discrepancy is harmless insofar as the protocol specification
70 * is concerned).
71 * If the mailbox is mistakenly allocated in the linear mapping
72 * by FW ioremap will fail since the mapping will be prevented
73 * by the kernel (it clashes with the linear mapping attributes
74 * specifications).
75 */
76 mailbox = ioremap(cpu_entry->mailbox_addr, sizeof(*mailbox));
77 if (!mailbox)
78 return -EIO;
79
80 cpu_id = readl_relaxed(&mailbox->cpu_id);
81 /*
82 * Check if firmware has set-up the mailbox entry properly
83 * before kickstarting the respective cpu.
84 */
85 if (cpu_id != ~0U) {
86 iounmap(mailbox);
87 return -ENXIO;
88 }
89
90 /*
91 * stash the mailbox address mapping to use it for further FW
92 * checks in the postboot method
93 */
94 cpu_entry->mailbox = mailbox;
95
96 /*
97 * We write the entry point and cpu id as LE regardless of the
98 * native endianness of the kernel. Therefore, any boot-loaders
99 * that read this address need to convert this address to the
100 * Boot-Loader's endianness before jumping.
101 */
102 writeq_relaxed(__pa_symbol(secondary_entry),
103 &mailbox->entry_point);
104 writel_relaxed(cpu_entry->gic_cpu_id, &mailbox->cpu_id);
105
106 arch_send_wakeup_ipi(cpu);
107
108 return 0;
109}
110
111static void acpi_parking_protocol_cpu_postboot(void)
112{
113 int cpu = smp_processor_id();
114 struct cpu_mailbox_entry *cpu_entry = &cpu_mailbox_entries[cpu];
115 struct parking_protocol_mailbox __iomem *mailbox = cpu_entry->mailbox;
116 u64 entry_point;
117
118 entry_point = readq_relaxed(&mailbox->entry_point);
119 /*
120 * Check if firmware has cleared the entry_point as expected
121 * by the protocol specification.
122 */
123 WARN_ON(entry_point);
124}
125
126const struct cpu_operations acpi_parking_protocol_ops = {
127 .name = "parking-protocol",
128 .cpu_init = acpi_parking_protocol_cpu_init,
129 .cpu_prepare = acpi_parking_protocol_cpu_prepare,
130 .cpu_boot = acpi_parking_protocol_cpu_boot,
131 .cpu_postboot = acpi_parking_protocol_cpu_postboot
132};