Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/arch/arm/vfp/vfpmodule.c |
| 3 | * |
| 4 | * Copyright (C) 2004 ARM Limited. |
| 5 | * Written by Deep Blue Solutions Limited. |
| 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 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include <linux/types.h> |
Russell King | 90b4419 | 2010-12-18 10:59:49 +0000 | [diff] [blame] | 12 | #include <linux/cpu.h> |
Colin Cross | 746a9d1 | 2011-02-10 02:08:32 -0800 | [diff] [blame] | 13 | #include <linux/cpu_pm.h> |
Will Deacon | 998de4a | 2012-05-11 17:42:37 +0100 | [diff] [blame] | 14 | #include <linux/hardirq.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/kernel.h> |
Russell King | 90b4419 | 2010-12-18 10:59:49 +0000 | [diff] [blame] | 16 | #include <linux/notifier.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/signal.h> |
Ingo Molnar | 3f07c01 | 2017-02-08 18:51:30 +0100 | [diff] [blame] | 18 | #include <linux/sched/signal.h> |
Russell King | 90b4419 | 2010-12-18 10:59:49 +0000 | [diff] [blame] | 19 | #include <linux/smp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | #include <linux/init.h> |
Will Deacon | 2498814 | 2012-04-23 15:38:28 +0100 | [diff] [blame] | 21 | #include <linux/uaccess.h> |
| 22 | #include <linux/user.h> |
Ard Biesheuvel | 73c132c | 2013-05-16 11:41:48 +0200 | [diff] [blame] | 23 | #include <linux/export.h> |
Russell King | d6551e8 | 2006-06-21 13:31:52 +0100 | [diff] [blame] | 24 | |
Russell King | 15d07dc | 2012-03-28 18:30:01 +0100 | [diff] [blame] | 25 | #include <asm/cp15.h> |
Tony Lindgren | 5aaf254 | 2010-07-01 13:41:05 +0100 | [diff] [blame] | 26 | #include <asm/cputype.h> |
David Howells | 9f97da7 | 2012-03-28 18:30:01 +0100 | [diff] [blame] | 27 | #include <asm/system_info.h> |
Russell King | d6551e8 | 2006-06-21 13:31:52 +0100 | [diff] [blame] | 28 | #include <asm/thread_notify.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | #include <asm/vfp.h> |
| 30 | |
| 31 | #include "vfpinstr.h" |
| 32 | #include "vfp.h" |
| 33 | |
| 34 | /* |
| 35 | * Our undef handlers (in entry.S) |
| 36 | */ |
Nicolas Pitre | a85b225 | 2016-11-16 22:20:14 +0100 | [diff] [blame] | 37 | asmlinkage void vfp_testing_entry(void); |
| 38 | asmlinkage void vfp_support_entry(void); |
| 39 | asmlinkage void vfp_null_entry(void); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | |
Nicolas Pitre | a85b225 | 2016-11-16 22:20:14 +0100 | [diff] [blame] | 41 | asmlinkage void (*vfp_vector)(void) = vfp_null_entry; |
Russell King | af61bdf | 2011-07-09 13:44:04 +0100 | [diff] [blame] | 42 | |
| 43 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | * Dual-use variable. |
| 45 | * Used in startup: set to non-zero if VFP checks fail |
| 46 | * After startup, holds VFP architecture |
| 47 | */ |
| 48 | unsigned int VFP_arch; |
| 49 | |
Russell King | 0d782dc | 2009-12-12 14:47:40 +0000 | [diff] [blame] | 50 | /* |
Russell King | f8f2a85 | 2011-07-09 16:09:43 +0100 | [diff] [blame] | 51 | * The pointer to the vfpstate structure of the thread which currently |
| 52 | * owns the context held in the VFP hardware, or NULL if the hardware |
| 53 | * context is invalid. |
| 54 | * |
| 55 | * For UP, this is sufficient to tell which thread owns the VFP context. |
| 56 | * However, for SMP, we also need to check the CPU number stored in the |
| 57 | * saved state too to catch migrations. |
| 58 | */ |
| 59 | union vfp_state *vfp_current_hw_state[NR_CPUS]; |
| 60 | |
| 61 | /* |
| 62 | * Is 'thread's most up to date state stored in this CPUs hardware? |
| 63 | * Must be called from non-preemptible context. |
| 64 | */ |
| 65 | static bool vfp_state_in_hw(unsigned int cpu, struct thread_info *thread) |
| 66 | { |
| 67 | #ifdef CONFIG_SMP |
| 68 | if (thread->vfpstate.hard.cpu != cpu) |
| 69 | return false; |
| 70 | #endif |
| 71 | return vfp_current_hw_state[cpu] == &thread->vfpstate; |
| 72 | } |
| 73 | |
| 74 | /* |
| 75 | * Force a reload of the VFP context from the thread structure. We do |
| 76 | * this by ensuring that access to the VFP hardware is disabled, and |
Santosh Shilimkar | 48af9fe | 2011-09-02 21:12:36 +0530 | [diff] [blame] | 77 | * clear vfp_current_hw_state. Must be called from non-preemptible context. |
Russell King | f8f2a85 | 2011-07-09 16:09:43 +0100 | [diff] [blame] | 78 | */ |
| 79 | static void vfp_force_reload(unsigned int cpu, struct thread_info *thread) |
| 80 | { |
| 81 | if (vfp_state_in_hw(cpu, thread)) { |
| 82 | fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN); |
| 83 | vfp_current_hw_state[cpu] = NULL; |
| 84 | } |
| 85 | #ifdef CONFIG_SMP |
| 86 | thread->vfpstate.hard.cpu = NR_CPUS; |
| 87 | #endif |
| 88 | } |
| 89 | |
| 90 | /* |
Russell King | 0d782dc | 2009-12-12 14:47:40 +0000 | [diff] [blame] | 91 | * Per-thread VFP initialization. |
| 92 | */ |
| 93 | static void vfp_thread_flush(struct thread_info *thread) |
| 94 | { |
| 95 | union vfp_state *vfp = &thread->vfpstate; |
| 96 | unsigned int cpu; |
| 97 | |
Russell King | 19dad35 | 2011-07-09 17:41:33 +0100 | [diff] [blame] | 98 | /* |
| 99 | * Disable VFP to ensure we initialize it first. We must ensure |
| 100 | * that the modification of vfp_current_hw_state[] and hardware |
| 101 | * disable are done for the same CPU and without preemption. |
| 102 | * |
| 103 | * Do this first to ensure that preemption won't overwrite our |
| 104 | * state saving should access to the VFP be enabled at this point. |
| 105 | */ |
| 106 | cpu = get_cpu(); |
| 107 | if (vfp_current_hw_state[cpu] == vfp) |
| 108 | vfp_current_hw_state[cpu] = NULL; |
| 109 | fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN); |
| 110 | put_cpu(); |
| 111 | |
Russell King | 0d782dc | 2009-12-12 14:47:40 +0000 | [diff] [blame] | 112 | memset(vfp, 0, sizeof(union vfp_state)); |
| 113 | |
| 114 | vfp->hard.fpexc = FPEXC_EN; |
| 115 | vfp->hard.fpscr = FPSCR_ROUND_NEAREST; |
Russell King | f8f2a85 | 2011-07-09 16:09:43 +0100 | [diff] [blame] | 116 | #ifdef CONFIG_SMP |
| 117 | vfp->hard.cpu = NR_CPUS; |
| 118 | #endif |
Russell King | 0d782dc | 2009-12-12 14:47:40 +0000 | [diff] [blame] | 119 | } |
| 120 | |
Russell King | 797245f | 2009-12-18 14:34:43 +0000 | [diff] [blame] | 121 | static void vfp_thread_exit(struct thread_info *thread) |
Russell King | 0d782dc | 2009-12-12 14:47:40 +0000 | [diff] [blame] | 122 | { |
| 123 | /* release case: Per-thread VFP cleanup. */ |
| 124 | union vfp_state *vfp = &thread->vfpstate; |
Russell King | 797245f | 2009-12-18 14:34:43 +0000 | [diff] [blame] | 125 | unsigned int cpu = get_cpu(); |
Russell King | 0d782dc | 2009-12-12 14:47:40 +0000 | [diff] [blame] | 126 | |
Russell King | af61bdf | 2011-07-09 13:44:04 +0100 | [diff] [blame] | 127 | if (vfp_current_hw_state[cpu] == vfp) |
| 128 | vfp_current_hw_state[cpu] = NULL; |
Russell King | 797245f | 2009-12-18 14:34:43 +0000 | [diff] [blame] | 129 | put_cpu(); |
Russell King | 0d782dc | 2009-12-12 14:47:40 +0000 | [diff] [blame] | 130 | } |
| 131 | |
Catalin Marinas | c98c097 | 2011-04-06 16:17:17 +0100 | [diff] [blame] | 132 | static void vfp_thread_copy(struct thread_info *thread) |
| 133 | { |
| 134 | struct thread_info *parent = current_thread_info(); |
| 135 | |
| 136 | vfp_sync_hwstate(parent); |
| 137 | thread->vfpstate = parent->vfpstate; |
Russell King | f8f2a85 | 2011-07-09 16:09:43 +0100 | [diff] [blame] | 138 | #ifdef CONFIG_SMP |
| 139 | thread->vfpstate.hard.cpu = NR_CPUS; |
| 140 | #endif |
Catalin Marinas | c98c097 | 2011-04-06 16:17:17 +0100 | [diff] [blame] | 141 | } |
| 142 | |
Russell King | 0d782dc | 2009-12-12 14:47:40 +0000 | [diff] [blame] | 143 | /* |
| 144 | * When this function is called with the following 'cmd's, the following |
| 145 | * is true while this function is being run: |
| 146 | * THREAD_NOFTIFY_SWTICH: |
| 147 | * - the previously running thread will not be scheduled onto another CPU. |
| 148 | * - the next thread to be run (v) will not be running on another CPU. |
| 149 | * - thread->cpu is the local CPU number |
| 150 | * - not preemptible as we're called in the middle of a thread switch |
| 151 | * THREAD_NOTIFY_FLUSH: |
| 152 | * - the thread (v) will be running on the local CPU, so |
| 153 | * v === current_thread_info() |
| 154 | * - thread->cpu is the local CPU number at the time it is accessed, |
| 155 | * but may change at any time. |
| 156 | * - we could be preempted if tree preempt rcu is enabled, so |
| 157 | * it is unsafe to use thread->cpu. |
Russell King | 797245f | 2009-12-18 14:34:43 +0000 | [diff] [blame] | 158 | * THREAD_NOTIFY_EXIT |
Russell King | 797245f | 2009-12-18 14:34:43 +0000 | [diff] [blame] | 159 | * - we could be preempted if tree preempt rcu is enabled, so |
| 160 | * it is unsafe to use thread->cpu. |
Russell King | 0d782dc | 2009-12-12 14:47:40 +0000 | [diff] [blame] | 161 | */ |
Russell King | d6551e8 | 2006-06-21 13:31:52 +0100 | [diff] [blame] | 162 | static int vfp_notifier(struct notifier_block *self, unsigned long cmd, void *v) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | { |
Russell King | d6551e8 | 2006-06-21 13:31:52 +0100 | [diff] [blame] | 164 | struct thread_info *thread = v; |
Catalin Marinas | 2e82669a | 2011-04-06 16:16:29 +0100 | [diff] [blame] | 165 | u32 fpexc; |
| 166 | #ifdef CONFIG_SMP |
| 167 | unsigned int cpu; |
| 168 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | |
Catalin Marinas | 2e82669a | 2011-04-06 16:16:29 +0100 | [diff] [blame] | 170 | switch (cmd) { |
| 171 | case THREAD_NOTIFY_SWITCH: |
| 172 | fpexc = fmrx(FPEXC); |
Catalin Marinas | c642846 | 2007-01-24 18:47:08 +0100 | [diff] [blame] | 173 | |
| 174 | #ifdef CONFIG_SMP |
Catalin Marinas | 2e82669a | 2011-04-06 16:16:29 +0100 | [diff] [blame] | 175 | cpu = thread->cpu; |
Russell King | 0d782dc | 2009-12-12 14:47:40 +0000 | [diff] [blame] | 176 | |
Catalin Marinas | c642846 | 2007-01-24 18:47:08 +0100 | [diff] [blame] | 177 | /* |
| 178 | * On SMP, if VFP is enabled, save the old state in |
| 179 | * case the thread migrates to a different CPU. The |
| 180 | * restoring is done lazily. |
| 181 | */ |
Russell King | f8f2a85 | 2011-07-09 16:09:43 +0100 | [diff] [blame] | 182 | if ((fpexc & FPEXC_EN) && vfp_current_hw_state[cpu]) |
Russell King | af61bdf | 2011-07-09 13:44:04 +0100 | [diff] [blame] | 183 | vfp_save_state(vfp_current_hw_state[cpu], fpexc); |
Catalin Marinas | c642846 | 2007-01-24 18:47:08 +0100 | [diff] [blame] | 184 | #endif |
| 185 | |
Russell King | 681a499 | 2006-08-27 12:38:34 +0100 | [diff] [blame] | 186 | /* |
| 187 | * Always disable VFP so we can lazily save/restore the |
| 188 | * old state. |
| 189 | */ |
Russell King | 228adef | 2007-07-18 09:37:10 +0100 | [diff] [blame] | 190 | fmxr(FPEXC, fpexc & ~FPEXC_EN); |
Catalin Marinas | 2e82669a | 2011-04-06 16:16:29 +0100 | [diff] [blame] | 191 | break; |
Russell King | 681a499 | 2006-08-27 12:38:34 +0100 | [diff] [blame] | 192 | |
Catalin Marinas | 2e82669a | 2011-04-06 16:16:29 +0100 | [diff] [blame] | 193 | case THREAD_NOTIFY_FLUSH: |
Russell King | 0d782dc | 2009-12-12 14:47:40 +0000 | [diff] [blame] | 194 | vfp_thread_flush(thread); |
Catalin Marinas | 2e82669a | 2011-04-06 16:16:29 +0100 | [diff] [blame] | 195 | break; |
| 196 | |
| 197 | case THREAD_NOTIFY_EXIT: |
Russell King | 797245f | 2009-12-18 14:34:43 +0000 | [diff] [blame] | 198 | vfp_thread_exit(thread); |
Catalin Marinas | 2e82669a | 2011-04-06 16:16:29 +0100 | [diff] [blame] | 199 | break; |
Catalin Marinas | c98c097 | 2011-04-06 16:17:17 +0100 | [diff] [blame] | 200 | |
| 201 | case THREAD_NOTIFY_COPY: |
| 202 | vfp_thread_copy(thread); |
| 203 | break; |
Catalin Marinas | 2e82669a | 2011-04-06 16:16:29 +0100 | [diff] [blame] | 204 | } |
Russell King | 681a499 | 2006-08-27 12:38:34 +0100 | [diff] [blame] | 205 | |
Russell King | d6551e8 | 2006-06-21 13:31:52 +0100 | [diff] [blame] | 206 | return NOTIFY_DONE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | } |
| 208 | |
Russell King | d6551e8 | 2006-06-21 13:31:52 +0100 | [diff] [blame] | 209 | static struct notifier_block vfp_notifier_block = { |
| 210 | .notifier_call = vfp_notifier, |
| 211 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | |
| 213 | /* |
| 214 | * Raise a SIGFPE for the current process. |
| 215 | * sicode describes the signal being raised. |
| 216 | */ |
Russell King | 2bbd7e9 | 2011-01-08 12:05:09 +0000 | [diff] [blame] | 217 | static void vfp_raise_sigfpe(unsigned int sicode, struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 218 | { |
| 219 | siginfo_t info; |
| 220 | |
Eric W. Biederman | 3eb0f51 | 2018-04-17 15:26:37 -0500 | [diff] [blame] | 221 | clear_siginfo(&info); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | info.si_signo = SIGFPE; |
| 223 | info.si_code = sicode; |
Al Viro | 35d59fc | 2006-10-11 17:22:44 +0100 | [diff] [blame] | 224 | info.si_addr = (void __user *)(instruction_pointer(regs) - 4); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | |
| 226 | /* |
| 227 | * This is the same as NWFPE, because it's not clear what |
| 228 | * this is used for |
| 229 | */ |
| 230 | current->thread.error_code = 0; |
| 231 | current->thread.trap_no = 6; |
| 232 | |
Russell King | da41119 | 2005-06-29 23:02:02 +0100 | [diff] [blame] | 233 | send_sig_info(SIGFPE, &info, current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | } |
| 235 | |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 236 | static void vfp_panic(char *reason, u32 inst) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | { |
| 238 | int i; |
| 239 | |
Nicolas Pitre | dc45707 | 2012-05-09 22:32:43 +0100 | [diff] [blame] | 240 | pr_err("VFP: Error: %s\n", reason); |
| 241 | pr_err("VFP: EXC 0x%08x SCR 0x%08x INST 0x%08x\n", |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 242 | fmrx(FPEXC), fmrx(FPSCR), inst); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | for (i = 0; i < 32; i += 2) |
Nicolas Pitre | dc45707 | 2012-05-09 22:32:43 +0100 | [diff] [blame] | 244 | pr_err("VFP: s%2u: 0x%08x s%2u: 0x%08x\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | i, vfp_get_float(i), i+1, vfp_get_float(i+1)); |
| 246 | } |
| 247 | |
| 248 | /* |
| 249 | * Process bitmask of exception conditions. |
| 250 | */ |
| 251 | static void vfp_raise_exceptions(u32 exceptions, u32 inst, u32 fpscr, struct pt_regs *regs) |
| 252 | { |
| 253 | int si_code = 0; |
| 254 | |
| 255 | pr_debug("VFP: raising exceptions %08x\n", exceptions); |
| 256 | |
Daniel Jacobowitz | 7c6f251 | 2006-08-27 12:42:08 +0100 | [diff] [blame] | 257 | if (exceptions == VFP_EXCEPTION_ERROR) { |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 258 | vfp_panic("unhandled bounce", inst); |
Russell King | 92d44a4 | 2018-04-13 00:22:47 +0100 | [diff] [blame] | 259 | vfp_raise_sigfpe(FPE_FLTINV, regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | return; |
| 261 | } |
| 262 | |
| 263 | /* |
Catalin Marinas | dbead40 | 2010-02-01 18:50:40 +0100 | [diff] [blame] | 264 | * If any of the status flags are set, update the FPSCR. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | * Comparison instructions always return at least one of |
| 266 | * these flags set. |
| 267 | */ |
Catalin Marinas | dbead40 | 2010-02-01 18:50:40 +0100 | [diff] [blame] | 268 | if (exceptions & (FPSCR_N|FPSCR_Z|FPSCR_C|FPSCR_V)) |
| 269 | fpscr &= ~(FPSCR_N|FPSCR_Z|FPSCR_C|FPSCR_V); |
| 270 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | fpscr |= exceptions; |
| 272 | |
| 273 | fmxr(FPSCR, fpscr); |
| 274 | |
| 275 | #define RAISE(stat,en,sig) \ |
| 276 | if (exceptions & stat && fpscr & en) \ |
| 277 | si_code = sig; |
| 278 | |
| 279 | /* |
| 280 | * These are arranged in priority order, least to highest. |
| 281 | */ |
Takashi Ohmasa | e0f205d | 2006-10-23 11:19:40 +0100 | [diff] [blame] | 282 | RAISE(FPSCR_DZC, FPSCR_DZE, FPE_FLTDIV); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 283 | RAISE(FPSCR_IXC, FPSCR_IXE, FPE_FLTRES); |
| 284 | RAISE(FPSCR_UFC, FPSCR_UFE, FPE_FLTUND); |
| 285 | RAISE(FPSCR_OFC, FPSCR_OFE, FPE_FLTOVF); |
| 286 | RAISE(FPSCR_IOC, FPSCR_IOE, FPE_FLTINV); |
| 287 | |
| 288 | if (si_code) |
| 289 | vfp_raise_sigfpe(si_code, regs); |
| 290 | } |
| 291 | |
| 292 | /* |
| 293 | * Emulate a VFP instruction. |
| 294 | */ |
| 295 | static u32 vfp_emulate_instruction(u32 inst, u32 fpscr, struct pt_regs *regs) |
| 296 | { |
Daniel Jacobowitz | 7c6f251 | 2006-08-27 12:42:08 +0100 | [diff] [blame] | 297 | u32 exceptions = VFP_EXCEPTION_ERROR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | |
| 299 | pr_debug("VFP: emulate: INST=0x%08x SCR=0x%08x\n", inst, fpscr); |
| 300 | |
| 301 | if (INST_CPRTDO(inst)) { |
| 302 | if (!INST_CPRT(inst)) { |
| 303 | /* |
| 304 | * CPDO |
| 305 | */ |
| 306 | if (vfp_single(inst)) { |
| 307 | exceptions = vfp_single_cpdo(inst, fpscr); |
| 308 | } else { |
| 309 | exceptions = vfp_double_cpdo(inst, fpscr); |
| 310 | } |
| 311 | } else { |
| 312 | /* |
| 313 | * A CPRT instruction can not appear in FPINST2, nor |
| 314 | * can it cause an exception. Therefore, we do not |
| 315 | * have to emulate it. |
| 316 | */ |
| 317 | } |
| 318 | } else { |
| 319 | /* |
| 320 | * A CPDT instruction can not appear in FPINST2, nor can |
| 321 | * it cause an exception. Therefore, we do not have to |
| 322 | * emulate it. |
| 323 | */ |
| 324 | } |
Russell King | 928bd1b | 2006-04-25 20:41:27 +0100 | [diff] [blame] | 325 | return exceptions & ~VFP_NAN_FLAG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | } |
| 327 | |
| 328 | /* |
| 329 | * Package up a bounce condition. |
| 330 | */ |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 331 | void VFP_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 332 | { |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 333 | u32 fpscr, orig_fpscr, fpsid, exceptions; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 334 | |
| 335 | pr_debug("VFP: bounce: trigger %08x fpexc %08x\n", trigger, fpexc); |
| 336 | |
| 337 | /* |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 338 | * At this point, FPEXC can have the following configuration: |
| 339 | * |
| 340 | * EX DEX IXE |
| 341 | * 0 1 x - synchronous exception |
| 342 | * 1 x 0 - asynchronous exception |
| 343 | * 1 x 1 - sychronous on VFP subarch 1 and asynchronous on later |
| 344 | * 0 0 1 - synchronous on VFP9 (non-standard subarch 1 |
| 345 | * implementation), undefined otherwise |
| 346 | * |
| 347 | * Clear various bits and enable access to the VFP so we can |
| 348 | * handle the bounce. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 349 | */ |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 350 | fmxr(FPEXC, fpexc & ~(FPEXC_EX|FPEXC_DEX|FPEXC_FP2V|FPEXC_VV|FPEXC_TRAP_MASK)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 352 | fpsid = fmrx(FPSID); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 353 | orig_fpscr = fpscr = fmrx(FPSCR); |
| 354 | |
| 355 | /* |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 356 | * Check for the special VFP subarch 1 and FPSCR.IXE bit case |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 357 | */ |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 358 | if ((fpsid & FPSID_ARCH_MASK) == (1 << FPSID_ARCH_BIT) |
| 359 | && (fpscr & FPSCR_IXE)) { |
| 360 | /* |
| 361 | * Synchronous exception, emulate the trigger instruction |
| 362 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | goto emulate; |
| 364 | } |
| 365 | |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 366 | if (fpexc & FPEXC_EX) { |
Catalin Marinas | 85d6943 | 2009-05-30 14:00:18 +0100 | [diff] [blame] | 367 | #ifndef CONFIG_CPU_FEROCEON |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 368 | /* |
| 369 | * Asynchronous exception. The instruction is read from FPINST |
| 370 | * and the interrupted instruction has to be restarted. |
| 371 | */ |
| 372 | trigger = fmrx(FPINST); |
| 373 | regs->ARM_pc -= 4; |
Catalin Marinas | 85d6943 | 2009-05-30 14:00:18 +0100 | [diff] [blame] | 374 | #endif |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 375 | } else if (!(fpexc & FPEXC_DEX)) { |
| 376 | /* |
| 377 | * Illegal combination of bits. It can be caused by an |
| 378 | * unallocated VFP instruction but with FPSCR.IXE set and not |
| 379 | * on VFP subarch 1. |
| 380 | */ |
| 381 | vfp_raise_exceptions(VFP_EXCEPTION_ERROR, trigger, fpscr, regs); |
George G. Davis | f2255be | 2009-04-01 20:27:18 +0100 | [diff] [blame] | 382 | goto exit; |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 383 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 384 | |
| 385 | /* |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 386 | * Modify fpscr to indicate the number of iterations remaining. |
| 387 | * If FPEXC.EX is 0, FPEXC.DEX is 1 and the FPEXC.VV bit indicates |
| 388 | * whether FPEXC.VECITR or FPSCR.LEN is used. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 389 | */ |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 390 | if (fpexc & (FPEXC_EX | FPEXC_VV)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | u32 len; |
| 392 | |
| 393 | len = fpexc + (1 << FPEXC_LENGTH_BIT); |
| 394 | |
| 395 | fpscr &= ~FPSCR_LENGTH_MASK; |
| 396 | fpscr |= (len & FPEXC_LENGTH_MASK) << (FPSCR_LENGTH_BIT - FPEXC_LENGTH_BIT); |
| 397 | } |
| 398 | |
| 399 | /* |
| 400 | * Handle the first FP instruction. We used to take note of the |
| 401 | * FPEXC bounce reason, but this appears to be unreliable. |
| 402 | * Emulate the bounced instruction instead. |
| 403 | */ |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 404 | exceptions = vfp_emulate_instruction(trigger, fpscr, regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 405 | if (exceptions) |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 406 | vfp_raise_exceptions(exceptions, trigger, orig_fpscr, regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 407 | |
| 408 | /* |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 409 | * If there isn't a second FP instruction, exit now. Note that |
| 410 | * the FPEXC.FP2V bit is valid only if FPEXC.EX is 1. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 411 | */ |
Russell King | 5e4ba61 | 2013-02-25 16:09:12 +0000 | [diff] [blame] | 412 | if ((fpexc & (FPEXC_EX | FPEXC_FP2V)) != (FPEXC_EX | FPEXC_FP2V)) |
George G. Davis | f2255be | 2009-04-01 20:27:18 +0100 | [diff] [blame] | 413 | goto exit; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 414 | |
| 415 | /* |
| 416 | * The barrier() here prevents fpinst2 being read |
| 417 | * before the condition above. |
| 418 | */ |
| 419 | barrier(); |
| 420 | trigger = fmrx(FPINST2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 421 | |
| 422 | emulate: |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 423 | exceptions = vfp_emulate_instruction(trigger, orig_fpscr, regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 424 | if (exceptions) |
| 425 | vfp_raise_exceptions(exceptions, trigger, orig_fpscr, regs); |
George G. Davis | f2255be | 2009-04-01 20:27:18 +0100 | [diff] [blame] | 426 | exit: |
| 427 | preempt_enable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 428 | } |
Russell King | efe90d2 | 2006-12-08 15:22:20 +0000 | [diff] [blame] | 429 | |
Russell King | 8e14036 | 2007-01-02 23:40:30 +0000 | [diff] [blame] | 430 | static void vfp_enable(void *unused) |
| 431 | { |
Will Deacon | 998de4a | 2012-05-11 17:42:37 +0100 | [diff] [blame] | 432 | u32 access; |
| 433 | |
| 434 | BUG_ON(preemptible()); |
| 435 | access = get_copro_access(); |
Russell King | 8e14036 | 2007-01-02 23:40:30 +0000 | [diff] [blame] | 436 | |
| 437 | /* |
| 438 | * Enable full access to VFP (cp10 and cp11) |
| 439 | */ |
| 440 | set_copro_access(access | CPACC_FULL(10) | CPACC_FULL(11)); |
| 441 | } |
| 442 | |
Florian Fainelli | 7d7d7a4 | 2015-04-17 16:53:58 -0700 | [diff] [blame] | 443 | /* Called by platforms on which we want to disable VFP because it may not be |
| 444 | * present on all CPUs within a SMP complex. Needs to be called prior to |
| 445 | * vfp_init(). |
| 446 | */ |
| 447 | void vfp_disable(void) |
| 448 | { |
| 449 | if (VFP_arch) { |
| 450 | pr_debug("%s: should be called prior to vfp_init\n", __func__); |
| 451 | return; |
| 452 | } |
| 453 | VFP_arch = 1; |
| 454 | } |
| 455 | |
Colin Cross | 746a9d1 | 2011-02-10 02:08:32 -0800 | [diff] [blame] | 456 | #ifdef CONFIG_CPU_PM |
Rafael J. Wysocki | 328f5cc | 2011-04-22 22:02:33 +0200 | [diff] [blame] | 457 | static int vfp_pm_suspend(void) |
Ben Dooks | fc0b7a2 | 2008-12-18 12:26:54 +0100 | [diff] [blame] | 458 | { |
| 459 | struct thread_info *ti = current_thread_info(); |
| 460 | u32 fpexc = fmrx(FPEXC); |
| 461 | |
| 462 | /* if vfp is on, then save state for resumption */ |
| 463 | if (fpexc & FPEXC_EN) { |
Nicolas Pitre | dc45707 | 2012-05-09 22:32:43 +0100 | [diff] [blame] | 464 | pr_debug("%s: saving vfp state\n", __func__); |
Ben Dooks | fc0b7a2 | 2008-12-18 12:26:54 +0100 | [diff] [blame] | 465 | vfp_save_state(&ti->vfpstate, fpexc); |
| 466 | |
| 467 | /* disable, just in case */ |
| 468 | fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN); |
Colin Cross | 24b3552 | 2012-07-20 02:03:42 +0100 | [diff] [blame] | 469 | } else if (vfp_current_hw_state[ti->cpu]) { |
| 470 | #ifndef CONFIG_SMP |
| 471 | fmxr(FPEXC, fpexc | FPEXC_EN); |
| 472 | vfp_save_state(vfp_current_hw_state[ti->cpu], fpexc); |
| 473 | fmxr(FPEXC, fpexc); |
| 474 | #endif |
Ben Dooks | fc0b7a2 | 2008-12-18 12:26:54 +0100 | [diff] [blame] | 475 | } |
| 476 | |
| 477 | /* clear any information we had about last context state */ |
Colin Cross | a84b895 | 2012-07-20 02:03:43 +0100 | [diff] [blame] | 478 | vfp_current_hw_state[ti->cpu] = NULL; |
Ben Dooks | fc0b7a2 | 2008-12-18 12:26:54 +0100 | [diff] [blame] | 479 | |
| 480 | return 0; |
| 481 | } |
| 482 | |
Rafael J. Wysocki | 328f5cc | 2011-04-22 22:02:33 +0200 | [diff] [blame] | 483 | static void vfp_pm_resume(void) |
Ben Dooks | fc0b7a2 | 2008-12-18 12:26:54 +0100 | [diff] [blame] | 484 | { |
| 485 | /* ensure we have access to the vfp */ |
| 486 | vfp_enable(NULL); |
| 487 | |
| 488 | /* and disable it to ensure the next usage restores the state */ |
| 489 | fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN); |
Ben Dooks | fc0b7a2 | 2008-12-18 12:26:54 +0100 | [diff] [blame] | 490 | } |
| 491 | |
Colin Cross | 746a9d1 | 2011-02-10 02:08:32 -0800 | [diff] [blame] | 492 | static int vfp_cpu_pm_notifier(struct notifier_block *self, unsigned long cmd, |
| 493 | void *v) |
| 494 | { |
| 495 | switch (cmd) { |
| 496 | case CPU_PM_ENTER: |
| 497 | vfp_pm_suspend(); |
| 498 | break; |
| 499 | case CPU_PM_ENTER_FAILED: |
| 500 | case CPU_PM_EXIT: |
| 501 | vfp_pm_resume(); |
| 502 | break; |
| 503 | } |
| 504 | return NOTIFY_OK; |
| 505 | } |
| 506 | |
| 507 | static struct notifier_block vfp_cpu_pm_notifier_block = { |
| 508 | .notifier_call = vfp_cpu_pm_notifier, |
Ben Dooks | fc0b7a2 | 2008-12-18 12:26:54 +0100 | [diff] [blame] | 509 | }; |
| 510 | |
Ben Dooks | fc0b7a2 | 2008-12-18 12:26:54 +0100 | [diff] [blame] | 511 | static void vfp_pm_init(void) |
| 512 | { |
Colin Cross | 746a9d1 | 2011-02-10 02:08:32 -0800 | [diff] [blame] | 513 | cpu_pm_register_notifier(&vfp_cpu_pm_notifier_block); |
Ben Dooks | fc0b7a2 | 2008-12-18 12:26:54 +0100 | [diff] [blame] | 514 | } |
| 515 | |
Ben Dooks | fc0b7a2 | 2008-12-18 12:26:54 +0100 | [diff] [blame] | 516 | #else |
| 517 | static inline void vfp_pm_init(void) { } |
Colin Cross | 746a9d1 | 2011-02-10 02:08:32 -0800 | [diff] [blame] | 518 | #endif /* CONFIG_CPU_PM */ |
Ben Dooks | fc0b7a2 | 2008-12-18 12:26:54 +0100 | [diff] [blame] | 519 | |
Russell King | f8f2a85 | 2011-07-09 16:09:43 +0100 | [diff] [blame] | 520 | /* |
| 521 | * Ensure that the VFP state stored in 'thread->vfpstate' is up to date |
| 522 | * with the hardware state. |
| 523 | */ |
Russell King | ad187f9 | 2010-02-06 11:36:23 +0000 | [diff] [blame] | 524 | void vfp_sync_hwstate(struct thread_info *thread) |
Catalin Marinas | 3d1228e | 2009-02-11 13:12:56 +0100 | [diff] [blame] | 525 | { |
| 526 | unsigned int cpu = get_cpu(); |
Catalin Marinas | 3d1228e | 2009-02-11 13:12:56 +0100 | [diff] [blame] | 527 | |
Russell King | f8f2a85 | 2011-07-09 16:09:43 +0100 | [diff] [blame] | 528 | if (vfp_state_in_hw(cpu, thread)) { |
Russell King | 54cb3db | 2010-02-06 11:27:45 +0000 | [diff] [blame] | 529 | u32 fpexc = fmrx(FPEXC); |
Catalin Marinas | 3d1228e | 2009-02-11 13:12:56 +0100 | [diff] [blame] | 530 | |
Russell King | 54cb3db | 2010-02-06 11:27:45 +0000 | [diff] [blame] | 531 | /* |
| 532 | * Save the last VFP state on this CPU. |
| 533 | */ |
| 534 | fmxr(FPEXC, fpexc | FPEXC_EN); |
| 535 | vfp_save_state(&thread->vfpstate, fpexc | FPEXC_EN); |
Russell King | ad187f9 | 2010-02-06 11:36:23 +0000 | [diff] [blame] | 536 | fmxr(FPEXC, fpexc); |
| 537 | } |
| 538 | |
| 539 | put_cpu(); |
| 540 | } |
| 541 | |
Russell King | f8f2a85 | 2011-07-09 16:09:43 +0100 | [diff] [blame] | 542 | /* Ensure that the thread reloads the hardware VFP state on the next use. */ |
Russell King | ad187f9 | 2010-02-06 11:36:23 +0000 | [diff] [blame] | 543 | void vfp_flush_hwstate(struct thread_info *thread) |
| 544 | { |
| 545 | unsigned int cpu = get_cpu(); |
Catalin Marinas | 3d1228e | 2009-02-11 13:12:56 +0100 | [diff] [blame] | 546 | |
Russell King | f8f2a85 | 2011-07-09 16:09:43 +0100 | [diff] [blame] | 547 | vfp_force_reload(cpu, thread); |
Catalin Marinas | 3d1228e | 2009-02-11 13:12:56 +0100 | [diff] [blame] | 548 | |
Catalin Marinas | 3d1228e | 2009-02-11 13:12:56 +0100 | [diff] [blame] | 549 | put_cpu(); |
| 550 | } |
Catalin Marinas | 3d1228e | 2009-02-11 13:12:56 +0100 | [diff] [blame] | 551 | |
Russell King | 90b4419 | 2010-12-18 10:59:49 +0000 | [diff] [blame] | 552 | /* |
Will Deacon | 2498814 | 2012-04-23 15:38:28 +0100 | [diff] [blame] | 553 | * Save the current VFP state into the provided structures and prepare |
| 554 | * for entry into a new function (signal handler). |
| 555 | */ |
| 556 | int vfp_preserve_user_clear_hwstate(struct user_vfp __user *ufp, |
| 557 | struct user_vfp_exc __user *ufp_exc) |
| 558 | { |
| 559 | struct thread_info *thread = current_thread_info(); |
| 560 | struct vfp_hard_struct *hwstate = &thread->vfpstate.hard; |
| 561 | int err = 0; |
| 562 | |
| 563 | /* Ensure that the saved hwstate is up-to-date. */ |
| 564 | vfp_sync_hwstate(thread); |
| 565 | |
| 566 | /* |
| 567 | * Copy the floating point registers. There can be unused |
| 568 | * registers see asm/hwcap.h for details. |
| 569 | */ |
| 570 | err |= __copy_to_user(&ufp->fpregs, &hwstate->fpregs, |
| 571 | sizeof(hwstate->fpregs)); |
| 572 | /* |
| 573 | * Copy the status and control register. |
| 574 | */ |
| 575 | __put_user_error(hwstate->fpscr, &ufp->fpscr, err); |
| 576 | |
| 577 | /* |
| 578 | * Copy the exception registers. |
| 579 | */ |
| 580 | __put_user_error(hwstate->fpexc, &ufp_exc->fpexc, err); |
| 581 | __put_user_error(hwstate->fpinst, &ufp_exc->fpinst, err); |
| 582 | __put_user_error(hwstate->fpinst2, &ufp_exc->fpinst2, err); |
| 583 | |
| 584 | if (err) |
| 585 | return -EFAULT; |
Will Deacon | ff9a184 | 2012-04-23 15:42:16 +0100 | [diff] [blame] | 586 | |
| 587 | /* Ensure that VFP is disabled. */ |
| 588 | vfp_flush_hwstate(thread); |
| 589 | |
| 590 | /* |
| 591 | * As per the PCS, clear the length and stride bits for function |
| 592 | * entry. |
| 593 | */ |
| 594 | hwstate->fpscr &= ~(FPSCR_LENGTH_MASK | FPSCR_STRIDE_MASK); |
Will Deacon | 2498814 | 2012-04-23 15:38:28 +0100 | [diff] [blame] | 595 | return 0; |
| 596 | } |
| 597 | |
| 598 | /* Sanitise and restore the current VFP state from the provided structures. */ |
Russell King | 42019fc | 2018-07-09 10:13:36 +0100 | [diff] [blame] | 599 | int vfp_restore_user_hwstate(struct user_vfp *ufp, struct user_vfp_exc *ufp_exc) |
Will Deacon | 2498814 | 2012-04-23 15:38:28 +0100 | [diff] [blame] | 600 | { |
| 601 | struct thread_info *thread = current_thread_info(); |
| 602 | struct vfp_hard_struct *hwstate = &thread->vfpstate.hard; |
| 603 | unsigned long fpexc; |
Will Deacon | 2498814 | 2012-04-23 15:38:28 +0100 | [diff] [blame] | 604 | |
Will Deacon | 56cb248 | 2012-05-15 15:51:54 +0100 | [diff] [blame] | 605 | /* Disable VFP to avoid corrupting the new thread state. */ |
| 606 | vfp_flush_hwstate(thread); |
Will Deacon | 2498814 | 2012-04-23 15:38:28 +0100 | [diff] [blame] | 607 | |
| 608 | /* |
| 609 | * Copy the floating point registers. There can be unused |
| 610 | * registers see asm/hwcap.h for details. |
| 611 | */ |
Russell King | 42019fc | 2018-07-09 10:13:36 +0100 | [diff] [blame] | 612 | memcpy(&hwstate->fpregs, &ufp->fpregs, sizeof(hwstate->fpregs)); |
Will Deacon | 2498814 | 2012-04-23 15:38:28 +0100 | [diff] [blame] | 613 | /* |
| 614 | * Copy the status and control register. |
| 615 | */ |
Russell King | 42019fc | 2018-07-09 10:13:36 +0100 | [diff] [blame] | 616 | hwstate->fpscr = ufp->fpscr; |
Will Deacon | 2498814 | 2012-04-23 15:38:28 +0100 | [diff] [blame] | 617 | |
| 618 | /* |
| 619 | * Sanitise and restore the exception registers. |
| 620 | */ |
Russell King | 42019fc | 2018-07-09 10:13:36 +0100 | [diff] [blame] | 621 | fpexc = ufp_exc->fpexc; |
Will Deacon | 2498814 | 2012-04-23 15:38:28 +0100 | [diff] [blame] | 622 | |
| 623 | /* Ensure the VFP is enabled. */ |
| 624 | fpexc |= FPEXC_EN; |
| 625 | |
| 626 | /* Ensure FPINST2 is invalid and the exception flag is cleared. */ |
| 627 | fpexc &= ~(FPEXC_EX | FPEXC_FP2V); |
| 628 | hwstate->fpexc = fpexc; |
| 629 | |
Russell King | 42019fc | 2018-07-09 10:13:36 +0100 | [diff] [blame] | 630 | hwstate->fpinst = ufp_exc->fpinst; |
| 631 | hwstate->fpinst2 = ufp_exc->fpinst2; |
Will Deacon | 2498814 | 2012-04-23 15:38:28 +0100 | [diff] [blame] | 632 | |
Russell King | 42019fc | 2018-07-09 10:13:36 +0100 | [diff] [blame] | 633 | return 0; |
Will Deacon | 2498814 | 2012-04-23 15:38:28 +0100 | [diff] [blame] | 634 | } |
| 635 | |
| 636 | /* |
Russell King | 90b4419 | 2010-12-18 10:59:49 +0000 | [diff] [blame] | 637 | * VFP hardware can lose all context when a CPU goes offline. |
Russell King | 74c25be | 2011-01-31 14:43:25 +0000 | [diff] [blame] | 638 | * As we will be running in SMP mode with CPU hotplug, we will save the |
| 639 | * hardware state at every thread switch. We clear our held state when |
| 640 | * a CPU has been killed, indicating that the VFP hardware doesn't contain |
| 641 | * a threads VFP state. When a CPU starts up, we re-enable access to the |
Thomas Gleixner | e5b61ba | 2016-07-13 17:16:35 +0000 | [diff] [blame] | 642 | * VFP hardware. The callbacks below are called on the CPU which |
Russell King | 90b4419 | 2010-12-18 10:59:49 +0000 | [diff] [blame] | 643 | * is being offlined/onlined. |
| 644 | */ |
Thomas Gleixner | e5b61ba | 2016-07-13 17:16:35 +0000 | [diff] [blame] | 645 | static int vfp_dying_cpu(unsigned int cpu) |
Russell King | 90b4419 | 2010-12-18 10:59:49 +0000 | [diff] [blame] | 646 | { |
Fabio Estevam | 1328f02 | 2018-01-22 12:20:26 +0100 | [diff] [blame] | 647 | vfp_current_hw_state[cpu] = NULL; |
Thomas Gleixner | e5b61ba | 2016-07-13 17:16:35 +0000 | [diff] [blame] | 648 | return 0; |
| 649 | } |
| 650 | |
| 651 | static int vfp_starting_cpu(unsigned int unused) |
| 652 | { |
| 653 | vfp_enable(NULL); |
| 654 | return 0; |
Russell King | 90b4419 | 2010-12-18 10:59:49 +0000 | [diff] [blame] | 655 | } |
Russell King | 8e14036 | 2007-01-02 23:40:30 +0000 | [diff] [blame] | 656 | |
Ard Biesheuvel | ab3da15 | 2013-05-24 16:23:28 +0200 | [diff] [blame] | 657 | void vfp_kmode_exception(void) |
| 658 | { |
| 659 | /* |
| 660 | * If we reach this point, a floating point exception has been raised |
| 661 | * while running in kernel mode. If the NEON/VFP unit was enabled at the |
| 662 | * time, it means a VFP instruction has been issued that requires |
| 663 | * software assistance to complete, something which is not currently |
| 664 | * supported in kernel mode. |
| 665 | * If the NEON/VFP unit was disabled, and the location pointed to below |
| 666 | * is properly preceded by a call to kernel_neon_begin(), something has |
| 667 | * caused the task to be scheduled out and back in again. In this case, |
| 668 | * rebuilding and running with CONFIG_DEBUG_ATOMIC_SLEEP enabled should |
| 669 | * be helpful in localizing the problem. |
| 670 | */ |
| 671 | if (fmrx(FPEXC) & FPEXC_EN) |
| 672 | pr_crit("BUG: unsupported FP instruction in kernel mode\n"); |
| 673 | else |
| 674 | pr_crit("BUG: FP instruction issued in kernel mode with FP unit disabled\n"); |
| 675 | } |
| 676 | |
Ard Biesheuvel | 73c132c | 2013-05-16 11:41:48 +0200 | [diff] [blame] | 677 | #ifdef CONFIG_KERNEL_MODE_NEON |
| 678 | |
| 679 | /* |
| 680 | * Kernel-side NEON support functions |
| 681 | */ |
| 682 | void kernel_neon_begin(void) |
| 683 | { |
| 684 | struct thread_info *thread = current_thread_info(); |
| 685 | unsigned int cpu; |
| 686 | u32 fpexc; |
| 687 | |
| 688 | /* |
| 689 | * Kernel mode NEON is only allowed outside of interrupt context |
| 690 | * with preemption disabled. This will make sure that the kernel |
| 691 | * mode NEON register contents never need to be preserved. |
| 692 | */ |
| 693 | BUG_ON(in_interrupt()); |
| 694 | cpu = get_cpu(); |
| 695 | |
| 696 | fpexc = fmrx(FPEXC) | FPEXC_EN; |
| 697 | fmxr(FPEXC, fpexc); |
| 698 | |
| 699 | /* |
| 700 | * Save the userland NEON/VFP state. Under UP, |
| 701 | * the owner could be a task other than 'current' |
| 702 | */ |
| 703 | if (vfp_state_in_hw(cpu, thread)) |
| 704 | vfp_save_state(&thread->vfpstate, fpexc); |
| 705 | #ifndef CONFIG_SMP |
| 706 | else if (vfp_current_hw_state[cpu] != NULL) |
| 707 | vfp_save_state(vfp_current_hw_state[cpu], fpexc); |
| 708 | #endif |
| 709 | vfp_current_hw_state[cpu] = NULL; |
| 710 | } |
| 711 | EXPORT_SYMBOL(kernel_neon_begin); |
| 712 | |
| 713 | void kernel_neon_end(void) |
| 714 | { |
| 715 | /* Disable the NEON/VFP unit. */ |
| 716 | fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN); |
| 717 | put_cpu(); |
| 718 | } |
| 719 | EXPORT_SYMBOL(kernel_neon_end); |
| 720 | |
| 721 | #endif /* CONFIG_KERNEL_MODE_NEON */ |
| 722 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 723 | /* |
| 724 | * VFP support code initialisation. |
| 725 | */ |
| 726 | static int __init vfp_init(void) |
| 727 | { |
| 728 | unsigned int vfpsid; |
Russell King | efe90d2 | 2006-12-08 15:22:20 +0000 | [diff] [blame] | 729 | unsigned int cpu_arch = cpu_architecture(); |
Russell King | efe90d2 | 2006-12-08 15:22:20 +0000 | [diff] [blame] | 730 | |
Thomas Gleixner | e5b61ba | 2016-07-13 17:16:35 +0000 | [diff] [blame] | 731 | /* |
| 732 | * Enable the access to the VFP on all online CPUs so the |
| 733 | * following test on FPSID will succeed. |
| 734 | */ |
Catalin Marinas | c98929c | 2007-11-22 18:32:01 +0100 | [diff] [blame] | 735 | if (cpu_arch >= CPU_ARCH_ARMv6) |
Will Deacon | 998de4a | 2012-05-11 17:42:37 +0100 | [diff] [blame] | 736 | on_each_cpu(vfp_enable, NULL, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 737 | |
| 738 | /* |
| 739 | * First check that there is a VFP that we can use. |
| 740 | * The handler is already setup to just log calls, so |
| 741 | * we just need to read the VFPSID register. |
| 742 | */ |
Russell King | 5d4cae5 | 2007-06-10 12:22:20 +0100 | [diff] [blame] | 743 | vfp_vector = vfp_testing_entry; |
Tzachi Perelstein | b9338a7 | 2007-09-09 14:24:59 +0100 | [diff] [blame] | 744 | barrier(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 745 | vfpsid = fmrx(FPSID); |
Russell King | 8e14036 | 2007-01-02 23:40:30 +0000 | [diff] [blame] | 746 | barrier(); |
Russell King | 5d4cae5 | 2007-06-10 12:22:20 +0100 | [diff] [blame] | 747 | vfp_vector = vfp_null_entry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 748 | |
Nicolas Pitre | dc45707 | 2012-05-09 22:32:43 +0100 | [diff] [blame] | 749 | pr_info("VFP support v0.3: "); |
Stephen Boyd | 6c96a4a | 2014-11-10 21:56:41 +0100 | [diff] [blame] | 750 | if (VFP_arch) { |
Nicolas Pitre | dc45707 | 2012-05-09 22:32:43 +0100 | [diff] [blame] | 751 | pr_cont("not present\n"); |
Stephen Boyd | 6c96a4a | 2014-11-10 21:56:41 +0100 | [diff] [blame] | 752 | return 0; |
| 753 | /* Extract the architecture on CPUID scheme */ |
| 754 | } else if ((read_cpuid_id() & 0x000f0000) == 0x000f0000) { |
| 755 | VFP_arch = vfpsid & FPSID_CPUID_ARCH_MASK; |
| 756 | VFP_arch >>= FPSID_ARCH_BIT; |
Catalin Marinas | 2bedbdf | 2008-11-06 13:23:07 +0000 | [diff] [blame] | 757 | /* |
| 758 | * Check for the presence of the Advanced SIMD |
| 759 | * load/store instructions, integer and single |
Tony Lindgren | 5aaf254 | 2010-07-01 13:41:05 +0100 | [diff] [blame] | 760 | * precision floating point operations. Only check |
| 761 | * for NEON if the hardware has the MVFR registers. |
Catalin Marinas | 2bedbdf | 2008-11-06 13:23:07 +0000 | [diff] [blame] | 762 | */ |
Stephen Boyd | 2b94fe2 | 2014-11-20 20:29:09 +0100 | [diff] [blame] | 763 | if (IS_ENABLED(CONFIG_NEON) && |
| 764 | (fmrx(MVFR1) & 0x000fff00) == 0x00011100) |
Stephen Boyd | 6c96a4a | 2014-11-10 21:56:41 +0100 | [diff] [blame] | 765 | elf_hwcap |= HWCAP_NEON; |
Stephen Boyd | 6c96a4a | 2014-11-10 21:56:41 +0100 | [diff] [blame] | 766 | |
Stephen Boyd | 2b94fe2 | 2014-11-20 20:29:09 +0100 | [diff] [blame] | 767 | if (IS_ENABLED(CONFIG_VFPv3)) { |
| 768 | u32 mvfr0 = fmrx(MVFR0); |
| 769 | if (((mvfr0 & MVFR0_DP_MASK) >> MVFR0_DP_BIT) == 0x2 || |
| 770 | ((mvfr0 & MVFR0_SP_MASK) >> MVFR0_SP_BIT) == 0x2) { |
| 771 | elf_hwcap |= HWCAP_VFPv3; |
| 772 | /* |
| 773 | * Check for VFPv3 D16 and VFPv4 D16. CPUs in |
| 774 | * this configuration only have 16 x 64bit |
| 775 | * registers. |
| 776 | */ |
| 777 | if ((mvfr0 & MVFR0_A_SIMD_MASK) == 1) |
| 778 | /* also v4-D16 */ |
| 779 | elf_hwcap |= HWCAP_VFPv3D16; |
| 780 | else |
| 781 | elf_hwcap |= HWCAP_VFPD32; |
| 782 | } |
| 783 | |
| 784 | if ((fmrx(MVFR1) & 0xf0000000) == 0x10000000) |
| 785 | elf_hwcap |= HWCAP_VFPv4; |
| 786 | } |
Stephen Boyd | 6c96a4a | 2014-11-10 21:56:41 +0100 | [diff] [blame] | 787 | /* Extract the architecture version on pre-cpuid scheme */ |
| 788 | } else { |
| 789 | if (vfpsid & FPSID_NODOUBLE) { |
| 790 | pr_cont("no double precision support\n"); |
| 791 | return 0; |
| 792 | } |
| 793 | |
| 794 | VFP_arch = (vfpsid & FPSID_ARCH_MASK) >> FPSID_ARCH_BIT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 795 | } |
Stephen Boyd | 6c96a4a | 2014-11-10 21:56:41 +0100 | [diff] [blame] | 796 | |
Thomas Gleixner | e5b61ba | 2016-07-13 17:16:35 +0000 | [diff] [blame] | 797 | cpuhp_setup_state_nocalls(CPUHP_AP_ARM_VFP_STARTING, |
Thomas Gleixner | 73c1b41 | 2016-12-21 20:19:54 +0100 | [diff] [blame] | 798 | "arm/vfp:starting", vfp_starting_cpu, |
Thomas Gleixner | e5b61ba | 2016-07-13 17:16:35 +0000 | [diff] [blame] | 799 | vfp_dying_cpu); |
Stephen Boyd | 6c96a4a | 2014-11-10 21:56:41 +0100 | [diff] [blame] | 800 | |
| 801 | vfp_vector = vfp_support_entry; |
| 802 | |
| 803 | thread_register_notifier(&vfp_notifier_block); |
| 804 | vfp_pm_init(); |
| 805 | |
| 806 | /* |
| 807 | * We detected VFP, and the support code is |
| 808 | * in place; report VFP support to userspace. |
| 809 | */ |
| 810 | elf_hwcap |= HWCAP_VFP; |
| 811 | |
| 812 | pr_cont("implementor %02x architecture %d part %02x variant %x rev %x\n", |
| 813 | (vfpsid & FPSID_IMPLEMENTER_MASK) >> FPSID_IMPLEMENTER_BIT, |
| 814 | VFP_arch, |
| 815 | (vfpsid & FPSID_PART_MASK) >> FPSID_PART_BIT, |
| 816 | (vfpsid & FPSID_VARIANT_MASK) >> FPSID_VARIANT_BIT, |
| 817 | (vfpsid & FPSID_REV_MASK) >> FPSID_REV_BIT); |
| 818 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 819 | return 0; |
| 820 | } |
| 821 | |
Ard Biesheuvel | 0773d73 | 2013-05-22 10:38:53 +0200 | [diff] [blame] | 822 | core_initcall(vfp_init); |