| 1 | /* |
| 2 | * arch/ubicom32/kernel/thread.c |
| 3 | * Ubicom32 architecture hardware thread support. |
| 4 | * |
| 5 | * (C) Copyright 2009, Ubicom, Inc. |
| 6 | * |
| 7 | * This file is part of the Ubicom32 Linux Kernel Port. |
| 8 | * |
| 9 | * The Ubicom32 Linux Kernel Port is free software: you can redistribute |
| 10 | * it and/or modify it under the terms of the GNU General Public License |
| 11 | * as published by the Free Software Foundation, either version 2 of the |
| 12 | * License, or (at your option) any later version. |
| 13 | * |
| 14 | * The Ubicom32 Linux Kernel Port is distributed in the hope that it |
| 15 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied |
| 16 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See |
| 17 | * the GNU General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU General Public License |
| 20 | * along with the Ubicom32 Linux Kernel Port. If not, |
| 21 | * see <http://www.gnu.org/licenses/>. |
| 22 | * |
| 23 | * Ubicom32 implementation derived from (with many thanks): |
| 24 | * arch/m68knommu |
| 25 | * arch/blackfin |
| 26 | * arch/parisc |
| 27 | */ |
| 28 | |
| 29 | #include <linux/module.h> |
| 30 | #include <linux/kernel.h> |
| 31 | #include <linux/init.h> |
| 32 | #include <linux/sched.h> |
| 33 | #include <linux/interrupt.h> |
| 34 | #include <linux/irq.h> |
| 35 | #include <linux/profile.h> |
| 36 | #include <linux/clocksource.h> |
| 37 | #include <linux/types.h> |
| 38 | #include <asm/ip5000.h> |
| 39 | #include <asm/machdep.h> |
| 40 | #include <asm/asm-offsets.h> |
| 41 | #include <asm/thread.h> |
| 42 | |
| 43 | /* |
| 44 | * TODO: At some point change the name here to be thread_ksp |
| 45 | */ |
| 46 | unsigned int sw_ksp[THREAD_ARCHITECTURAL_MAX]; |
| 47 | |
| 48 | static unsigned int thread_mask = -1; |
| 49 | static unsigned int thread_mainline_mask; |
| 50 | |
| 51 | /* |
| 52 | * thread_entry() |
| 53 | * Returning from the called function will disable the thread. |
| 54 | * |
| 55 | * This could be a naked call to allow for hwthreads that do not have stacks. |
| 56 | * However, with -O0, the code still writes to thex stack, and this was |
| 57 | * corrupting memory just after the callers stack. |
| 58 | */ |
| 59 | static void thread_entry(void *arg, thread_exec_fn_t exec) |
| 60 | { |
| 61 | /* |
| 62 | * Call thread function |
| 63 | */ |
| 64 | exec(arg); |
| 65 | |
| 66 | /* |
| 67 | * Complete => Disable self |
| 68 | */ |
| 69 | thread_disable(thread_get_self()); |
| 70 | } |
| 71 | |
| 72 | /* |
| 73 | * thread_start() |
| 74 | * Start the specified function on the specified hardware thread. |
| 75 | */ |
| 76 | thread_t thread_start(thread_t thread, |
| 77 | thread_exec_fn_t exec, |
| 78 | void *arg, |
| 79 | unsigned int *sp_high, |
| 80 | thread_type_t type) |
| 81 | { |
| 82 | /* |
| 83 | * Sanity check |
| 84 | */ |
| 85 | unsigned int enabled, mask, csr; |
| 86 | asm volatile ( |
| 87 | "move.4 %0, MT_EN\n\t" |
| 88 | : "=m" (enabled) |
| 89 | ); |
| 90 | |
| 91 | mask = 1 << thread; |
| 92 | if (enabled & mask) { |
| 93 | printk(KERN_WARNING "request to enable a previously enabled thread\n"); |
| 94 | return (thread_t)-1; |
| 95 | } |
| 96 | |
| 97 | /* |
| 98 | * Update thread state |
| 99 | */ |
| 100 | csr = (thread << 15) | (1 << 14); |
| 101 | asm volatile ( |
| 102 | "setcsr %0 \n\t" |
| 103 | "setcsr_flush 0 \n\t" |
| 104 | |
| 105 | "move.4 A0, #0 \n\t" |
| 106 | "move.4 A1, #0 \n\t" |
| 107 | "move.4 A2, #0 \n\t" |
| 108 | "move.4 A3, #0 \n\t" |
| 109 | "move.4 A4, #0 \n\t" |
| 110 | "move.4 A5, #0 \n\t" |
| 111 | "move.4 A6, #0 \n\t" |
| 112 | "move.4 SP, %4 \n\t" /* A7 is SP */ |
| 113 | |
| 114 | "move.4 D0, %3 \n\t" |
| 115 | "move.4 D1, %2 \n\t" |
| 116 | "move.4 D2, #0 \n\t" |
| 117 | "move.4 D3, #0 \n\t" |
| 118 | "move.4 D4, #0 \n\t" |
| 119 | "move.4 D5, #0 \n\t" |
| 120 | "move.4 D6, #0 \n\t" |
| 121 | "move.4 D7, #0 \n\t" |
| 122 | "move.4 D8, #0 \n\t" |
| 123 | "move.4 D9, #0 \n\t" |
| 124 | "move.4 D10, #0 \n\t" |
| 125 | "move.4 D11, #0 \n\t" |
| 126 | "move.4 D12, #0 \n\t" |
| 127 | "move.4 D13, #0 \n\t" |
| 128 | "move.4 D14, #0 \n\t" |
| 129 | "move.4 D15, #0 \n\t" |
| 130 | |
| 131 | "move.4 INT_MASK0, #0 \n\t" |
| 132 | "move.4 INT_MASK1, #0 \n\t" |
| 133 | "move.4 PC, %1 \n\t" |
| 134 | "setcsr #0 \n\t" |
| 135 | "setcsr_flush 0 \n\t" |
| 136 | : |
| 137 | : "r" (csr), "r" (thread_entry), "r" (exec), |
| 138 | "r" (arg), "r" (sp_high) |
| 139 | ); |
| 140 | |
| 141 | /* |
| 142 | * Apply HRT state |
| 143 | */ |
| 144 | if (type & THREAD_TYPE_HRT) { |
| 145 | asm volatile ( |
| 146 | "or.4 MT_HRT, MT_HRT, %0\n\t" |
| 147 | : |
| 148 | : "d" (mask) |
| 149 | : "cc" |
| 150 | ); |
| 151 | } else { |
| 152 | asm volatile ( |
| 153 | "and.4 MT_HRT, MT_HRT, %0\n\t" |
| 154 | : |
| 155 | : "d" (~mask) |
| 156 | : "cc" |
| 157 | ); |
| 158 | } |
| 159 | |
| 160 | /* |
| 161 | * Set priority |
| 162 | */ |
| 163 | asm volatile ( |
| 164 | "or.4 MT_HPRI, MT_HPRI, %0\n\t" |
| 165 | : |
| 166 | : "d" (mask) |
| 167 | : "cc" |
| 168 | ); |
| 169 | |
| 170 | /* |
| 171 | * Enable thread |
| 172 | */ |
| 173 | asm volatile ( |
| 174 | "move.4 MT_ACTIVE_SET, %0 \n\t" |
| 175 | : |
| 176 | : "d" (mask) |
| 177 | ); |
| 178 | thread_enable_mask(mask); |
| 179 | return thread; |
| 180 | } |
| 181 | |
| 182 | /* |
| 183 | * thread_get_mainline() |
| 184 | * Return a mask of those threads that are Linux mainline threads. |
| 185 | */ |
| 186 | unsigned int thread_get_mainline(void) |
| 187 | { |
| 188 | return thread_mainline_mask; |
| 189 | } |
| 190 | |
| 191 | /* |
| 192 | * thread_set_mainline() |
| 193 | * Indicate that the specified thread is a Linux mainline thread. |
| 194 | */ |
| 195 | void thread_set_mainline(thread_t tid) |
| 196 | { |
| 197 | thread_mainline_mask |= (1 << tid); |
| 198 | } |
| 199 | |
| 200 | /* |
| 201 | * thread_alloc() |
| 202 | * Allocate an unused hardware thread. |
| 203 | */ |
| 204 | thread_t thread_alloc(void) |
| 205 | { |
| 206 | thread_t tid; |
| 207 | |
| 208 | /* |
| 209 | * If this is the first time we are here get the list of unused |
| 210 | * threads from the processor device tree node. |
| 211 | */ |
| 212 | if (thread_mask == -1) { |
| 213 | thread_mask = processor_threads(); |
| 214 | } |
| 215 | |
| 216 | if (!thread_mask) { |
| 217 | return (thread_t)-1; |
| 218 | } |
| 219 | |
| 220 | tid = ffs(thread_mask); |
| 221 | if (tid != 0) { |
| 222 | tid--; |
| 223 | thread_mask &= ~(1 << tid); |
| 224 | return tid; |
| 225 | } |
| 226 | |
| 227 | return (thread_t)-1; |
| 228 | } |
| 229 | |
