Lorenzo Pieralisi | 5e89c55 | 2016-01-26 11:10:38 +0000 | [diff] [blame] | 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 | |
Lorenzo Pieralisi | c1e4659 | 2016-02-26 11:50:12 +0000 | [diff] [blame] | 24 | struct parking_protocol_mailbox { |
| 25 | __le32 cpu_id; |
| 26 | __le32 reserved; |
| 27 | __le64 entry_point; |
| 28 | }; |
| 29 | |
Lorenzo Pieralisi | 5e89c55 | 2016-01-26 11:10:38 +0000 | [diff] [blame] | 30 | struct cpu_mailbox_entry { |
Lorenzo Pieralisi | c1e4659 | 2016-02-26 11:50:12 +0000 | [diff] [blame] | 31 | struct parking_protocol_mailbox __iomem *mailbox; |
Lorenzo Pieralisi | 5e89c55 | 2016-01-26 11:10:38 +0000 | [diff] [blame] | 32 | phys_addr_t mailbox_addr; |
| 33 | u8 version; |
| 34 | u8 gic_cpu_id; |
| 35 | }; |
| 36 | |
| 37 | static struct cpu_mailbox_entry cpu_mailbox_entries[NR_CPUS]; |
| 38 | |
| 39 | void __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 | |
| 49 | bool 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 | |
| 56 | static 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 | |
| 64 | static int acpi_parking_protocol_cpu_prepare(unsigned int cpu) |
| 65 | { |
| 66 | return 0; |
| 67 | } |
| 68 | |
Lorenzo Pieralisi | 5e89c55 | 2016-01-26 11:10:38 +0000 | [diff] [blame] | 69 | static 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 | /* |
Lorenzo Pieralisi | c1e4659 | 2016-02-26 11:50:12 +0000 | [diff] [blame] | 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 | /* |
Lorenzo Pieralisi | 5e89c55 | 2016-01-26 11:10:38 +0000 | [diff] [blame] | 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 | |
Lorenzo Pieralisi | 5e89c55 | 2016-01-26 11:10:38 +0000 | [diff] [blame] | 117 | return 0; |
| 118 | } |
| 119 | |
| 120 | static 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]; |
Lorenzo Pieralisi | c1e4659 | 2016-02-26 11:50:12 +0000 | [diff] [blame] | 124 | struct parking_protocol_mailbox __iomem *mailbox = cpu_entry->mailbox; |
Lorenzo Pieralisi | 5e89c55 | 2016-01-26 11:10:38 +0000 | [diff] [blame] | 125 | __le64 entry_point; |
| 126 | |
Lorenzo Pieralisi | 5e89c55 | 2016-01-26 11:10:38 +0000 | [diff] [blame] | 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); |
Lorenzo Pieralisi | 5e89c55 | 2016-01-26 11:10:38 +0000 | [diff] [blame] | 133 | } |
| 134 | |
| 135 | const 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 | }; |