Marc Zyngier | d329de3 | 2013-01-02 15:24:22 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Spin Table SMP initialisation |
| 3 | * |
| 4 | * Copyright (C) 2013 ARM Ltd. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 17 | */ |
| 18 | |
Mark Rutland | 652af89 | 2013-10-24 20:30:16 +0100 | [diff] [blame] | 19 | #include <linux/delay.h> |
Marc Zyngier | d329de3 | 2013-01-02 15:24:22 +0000 | [diff] [blame] | 20 | #include <linux/init.h> |
| 21 | #include <linux/of.h> |
| 22 | #include <linux/smp.h> |
Mark Rutland | 113954c | 2014-07-30 11:59:02 +0100 | [diff] [blame^] | 23 | #include <linux/types.h> |
Marc Zyngier | d329de3 | 2013-01-02 15:24:22 +0000 | [diff] [blame] | 24 | |
| 25 | #include <asm/cacheflush.h> |
Mark Rutland | cd1aebf | 2013-10-24 20:30:15 +0100 | [diff] [blame] | 26 | #include <asm/cpu_ops.h> |
Mark Rutland | 652af89 | 2013-10-24 20:30:16 +0100 | [diff] [blame] | 27 | #include <asm/cputype.h> |
| 28 | #include <asm/smp_plat.h> |
| 29 | |
| 30 | extern void secondary_holding_pen(void); |
| 31 | volatile unsigned long secondary_holding_pen_release = INVALID_HWID; |
Marc Zyngier | d329de3 | 2013-01-02 15:24:22 +0000 | [diff] [blame] | 32 | |
| 33 | static phys_addr_t cpu_release_addr[NR_CPUS]; |
Mark Rutland | 652af89 | 2013-10-24 20:30:16 +0100 | [diff] [blame] | 34 | |
| 35 | /* |
| 36 | * Write secondary_holding_pen_release in a way that is guaranteed to be |
| 37 | * visible to all observers, irrespective of whether they're taking part |
| 38 | * in coherency or not. This is necessary for the hotplug code to work |
| 39 | * reliably. |
| 40 | */ |
| 41 | static void write_pen_release(u64 val) |
| 42 | { |
| 43 | void *start = (void *)&secondary_holding_pen_release; |
| 44 | unsigned long size = sizeof(secondary_holding_pen_release); |
| 45 | |
| 46 | secondary_holding_pen_release = val; |
| 47 | __flush_dcache_area(start, size); |
| 48 | } |
| 49 | |
Marc Zyngier | d329de3 | 2013-01-02 15:24:22 +0000 | [diff] [blame] | 50 | |
Mark Rutland | cd1aebf | 2013-10-24 20:30:15 +0100 | [diff] [blame] | 51 | static int smp_spin_table_cpu_init(struct device_node *dn, unsigned int cpu) |
Marc Zyngier | d329de3 | 2013-01-02 15:24:22 +0000 | [diff] [blame] | 52 | { |
| 53 | /* |
| 54 | * Determine the address from which the CPU is polling. |
| 55 | */ |
| 56 | if (of_property_read_u64(dn, "cpu-release-addr", |
| 57 | &cpu_release_addr[cpu])) { |
| 58 | pr_err("CPU %d: missing or invalid cpu-release-addr property\n", |
| 59 | cpu); |
| 60 | |
| 61 | return -1; |
| 62 | } |
| 63 | |
| 64 | return 0; |
| 65 | } |
| 66 | |
Mark Rutland | cd1aebf | 2013-10-24 20:30:15 +0100 | [diff] [blame] | 67 | static int smp_spin_table_cpu_prepare(unsigned int cpu) |
Marc Zyngier | d329de3 | 2013-01-02 15:24:22 +0000 | [diff] [blame] | 68 | { |
Mark Rutland | 113954c | 2014-07-30 11:59:02 +0100 | [diff] [blame^] | 69 | __le64 __iomem *release_addr; |
Marc Zyngier | d329de3 | 2013-01-02 15:24:22 +0000 | [diff] [blame] | 70 | |
| 71 | if (!cpu_release_addr[cpu]) |
| 72 | return -ENODEV; |
| 73 | |
Mark Rutland | 113954c | 2014-07-30 11:59:02 +0100 | [diff] [blame^] | 74 | /* |
| 75 | * The cpu-release-addr may or may not be inside the linear mapping. |
| 76 | * As ioremap_cache will either give us a new mapping or reuse the |
| 77 | * existing linear mapping, we can use it to cover both cases. In |
| 78 | * either case the memory will be MT_NORMAL. |
| 79 | */ |
| 80 | release_addr = ioremap_cache(cpu_release_addr[cpu], |
| 81 | sizeof(*release_addr)); |
| 82 | if (!release_addr) |
| 83 | return -ENOMEM; |
Matthew Leach | 710be9a | 2013-10-11 14:52:18 +0100 | [diff] [blame] | 84 | |
| 85 | /* |
| 86 | * We write the release address as LE regardless of the native |
| 87 | * endianess of the kernel. Therefore, any boot-loaders that |
| 88 | * read this address need to convert this address to the |
| 89 | * boot-loader's endianess before jumping. This is mandated by |
| 90 | * the boot protocol. |
| 91 | */ |
Mark Rutland | 113954c | 2014-07-30 11:59:02 +0100 | [diff] [blame^] | 92 | writeq_relaxed(__pa(secondary_holding_pen), release_addr); |
| 93 | __flush_dcache_area((__force void *)release_addr, |
| 94 | sizeof(*release_addr)); |
Marc Zyngier | d329de3 | 2013-01-02 15:24:22 +0000 | [diff] [blame] | 95 | |
| 96 | /* |
| 97 | * Send an event to wake up the secondary CPU. |
| 98 | */ |
| 99 | sev(); |
| 100 | |
Mark Rutland | 113954c | 2014-07-30 11:59:02 +0100 | [diff] [blame^] | 101 | iounmap(release_addr); |
| 102 | |
Marc Zyngier | d329de3 | 2013-01-02 15:24:22 +0000 | [diff] [blame] | 103 | return 0; |
| 104 | } |
| 105 | |
Mark Rutland | 652af89 | 2013-10-24 20:30:16 +0100 | [diff] [blame] | 106 | static int smp_spin_table_cpu_boot(unsigned int cpu) |
| 107 | { |
Mark Rutland | 652af89 | 2013-10-24 20:30:16 +0100 | [diff] [blame] | 108 | /* |
| 109 | * Update the pen release flag. |
| 110 | */ |
| 111 | write_pen_release(cpu_logical_map(cpu)); |
| 112 | |
| 113 | /* |
| 114 | * Send an event, causing the secondaries to read pen_release. |
| 115 | */ |
| 116 | sev(); |
| 117 | |
Catalin Marinas | 6400111 | 2014-04-04 11:49:05 +0100 | [diff] [blame] | 118 | return 0; |
Mark Rutland | 652af89 | 2013-10-24 20:30:16 +0100 | [diff] [blame] | 119 | } |
| 120 | |
Mark Rutland | cd1aebf | 2013-10-24 20:30:15 +0100 | [diff] [blame] | 121 | const struct cpu_operations smp_spin_table_ops = { |
Marc Zyngier | d329de3 | 2013-01-02 15:24:22 +0000 | [diff] [blame] | 122 | .name = "spin-table", |
Mark Rutland | cd1aebf | 2013-10-24 20:30:15 +0100 | [diff] [blame] | 123 | .cpu_init = smp_spin_table_cpu_init, |
| 124 | .cpu_prepare = smp_spin_table_cpu_prepare, |
Mark Rutland | 652af89 | 2013-10-24 20:30:16 +0100 | [diff] [blame] | 125 | .cpu_boot = smp_spin_table_cpu_boot, |
Marc Zyngier | d329de3 | 2013-01-02 15:24:22 +0000 | [diff] [blame] | 126 | }; |