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authorAndy Lutomirski <luto@kernel.org>2016-01-24 17:38:08 -0500
committerIngo Molnar <mingo@kernel.org>2016-02-09 09:42:55 -0500
commita20d7297045f7fdcd676c15243192eb0e95a4306 (patch)
treeeb278a36d802bd6d56852ef90e6aeae76a48de15
parent5ed73f40735c68d8a656b46d09b1885d3b8740ae (diff)
x86/fpu: Fold fpu_copy() into fpu__copy()
Splitting it into two functions needlessly obfuscated the code. While we're at it, improve the comment slightly. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/3eb5a63a9c5c84077b2677a7dfe684eef96fe59e.1453675014.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--arch/x86/kernel/fpu/core.c32
1 files changed, 11 insertions, 21 deletions
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 7a9244df33e2..299b58bb975b 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -231,14 +231,15 @@ void fpstate_init(union fpregs_state *state)
231} 231}
232EXPORT_SYMBOL_GPL(fpstate_init); 232EXPORT_SYMBOL_GPL(fpstate_init);
233 233
234/* 234int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu)
235 * Copy the current task's FPU state to a new task's FPU context.
236 *
237 * In both the 'eager' and the 'lazy' case we save hardware registers
238 * directly to the destination buffer.
239 */
240static void fpu_copy(struct fpu *dst_fpu, struct fpu *src_fpu)
241{ 235{
236 dst_fpu->counter = 0;
237 dst_fpu->fpregs_active = 0;
238 dst_fpu->last_cpu = -1;
239
240 if (!src_fpu->fpstate_active || !cpu_has_fpu)
241 return 0;
242
242 WARN_ON_FPU(src_fpu != &current->thread.fpu); 243 WARN_ON_FPU(src_fpu != &current->thread.fpu);
243 244
244 /* 245 /*
@@ -251,10 +252,9 @@ static void fpu_copy(struct fpu *dst_fpu, struct fpu *src_fpu)
251 /* 252 /*
252 * Save current FPU registers directly into the child 253 * Save current FPU registers directly into the child
253 * FPU context, without any memory-to-memory copying. 254 * FPU context, without any memory-to-memory copying.
254 * 255 * In lazy mode, if the FPU context isn't loaded into
255 * If the FPU context got destroyed in the process (FNSAVE 256 * fpregs, CR0.TS will be set and do_device_not_available
256 * done on old CPUs) then copy it back into the source 257 * will load the FPU context.
257 * context and mark the current task for lazy restore.
258 * 258 *
259 * We have to do all this with preemption disabled, 259 * We have to do all this with preemption disabled,
260 * mostly because of the FNSAVE case, because in that 260 * mostly because of the FNSAVE case, because in that
@@ -274,16 +274,6 @@ static void fpu_copy(struct fpu *dst_fpu, struct fpu *src_fpu)
274 fpregs_deactivate(src_fpu); 274 fpregs_deactivate(src_fpu);
275 } 275 }
276 preempt_enable(); 276 preempt_enable();
277}
278
279int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu)
280{
281 dst_fpu->counter = 0;
282 dst_fpu->fpregs_active = 0;
283 dst_fpu->last_cpu = -1;
284
285 if (src_fpu->fpstate_active && cpu_has_fpu)
286 fpu_copy(dst_fpu, src_fpu);
287 277
288 return 0; 278 return 0;
289} 279}