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From: riel@redhat.com
To: linux-kernel@vger.kernel.org
Cc: dave.hansen@linux.intel.com, x86@kernel.org, tglx@linutronix.de,
	pbonzini@redhat.com, mingo@redhat.com, luto@kernel.org,
	pa@zytor.com, bp@suse.de
Subject: [PATCH 9/9] x86/fpu: split old & new fpu code paths
Date: Tue,  4 Oct 2016 20:34:38 -0400	[thread overview]
Message-ID: <1475627678-20788-10-git-send-email-riel@redhat.com> (raw)
In-Reply-To: <1475627678-20788-1-git-send-email-riel@redhat.com>

From: Rik van Riel <riel@redhat.com>

Now that CR0.TS is no longer being manipulated, we can simplify
switch_fpu_prepare by no longer nesting the handling of the new
fpu inside the two branches for the old FPU.

Signed-off-by: Rik van Riel <riel@redhat.com>
---
 arch/x86/include/asm/fpu/internal.h | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index aa7a117b43f8..ef52935f8a17 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -581,23 +581,17 @@ switch_fpu_prepare(struct fpu *old_fpu, struct fpu *new_fpu, int cpu)
 		/* But leave fpu_fpregs_owner_ctx! */
 		old_fpu->fpregs_active = 0;
 		trace_x86_fpu_regs_deactivated(old_fpu);
+	} else
+		old_fpu->last_cpu = -1;
 
-		/* Don't change CR0.TS if we just switch! */
-		if (fpu.preload) {
-			fpregs_activate(new_fpu);
-			trace_x86_fpu_regs_activated(new_fpu);
+	if (fpu.preload) {
+		if (fpregs_state_valid(new_fpu, cpu))
+			fpu.preload = 0;
+		else
 			prefetch(&new_fpu->state);
-		}
-	} else {
-		old_fpu->last_cpu = -1;
-		if (fpu.preload) {
-			if (fpregs_state_valid(new_fpu, cpu))
-				fpu.preload = 0;
-			else
-				prefetch(&new_fpu->state);
-			fpregs_activate(new_fpu);
-		}
+		fpregs_activate(new_fpu);
 	}
+
 	return fpu;
 }
 
-- 
2.7.4

  parent reply	other threads:[~2016-10-05  0:34 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-05  0:34 [PATCH 0/9] x86/fpu: remove lazy FPU mode & various FPU cleanups riel
2016-10-05  0:34 ` [PATCH 1/9] x86/crypto: Remove X86_FEATURE_EAGER_FPU ifdef from the crc32c code riel
2016-10-05  0:40   ` Rik van Riel
2016-10-07  9:43   ` [tip:x86/fpu] x86/crypto, x86/fpu: Remove X86_FEATURE_EAGER_FPU #ifdef " tip-bot for Andy Lutomirski
2016-10-05  0:34 ` [PATCH 2/9] x86/fpu: Hard-disable lazy fpu mode riel
2016-10-05  7:14   ` Paolo Bonzini
2016-10-05 13:57     ` Rik van Riel
2016-10-05 14:03       ` Paolo Bonzini
2016-10-05 15:59         ` Andy Lutomirski
2016-10-05 16:09           ` Paolo Bonzini
2016-10-07  9:43   ` [tip:x86/fpu] x86/fpu: Hard-disable lazy FPU mode tip-bot for Andy Lutomirski
2016-10-05  0:34 ` [PATCH 3/9] x86/fpu: Remove the XFEATURE_MASK_EAGER/LAZY distinction riel
2016-10-07  9:44   ` [tip:x86/fpu] " tip-bot for Andy Lutomirski
2016-10-05  0:34 ` [PATCH 4/9] x86/fpu: Remove use_eager_fpu() riel
2016-10-07  9:44   ` [tip:x86/fpu] " tip-bot for Andy Lutomirski
2016-10-05  0:34 ` [PATCH 5/9] x86/fpu: remove fpu.counter riel
2016-10-05  2:07   ` Andy Lutomirski
2016-10-07  9:45   ` [tip:x86/fpu] x86/fpu: Remove struct fpu::counter tip-bot for Rik van Riel
2016-10-05  0:34 ` [PATCH 6/9] x86/fpu,kvm: remove kvm vcpu->fpu_counter riel
2016-10-07  9:45   ` [tip:x86/fpu] x86/fpu, kvm: Remove KVM vcpu->fpu_counter tip-bot for Rik van Riel
2016-10-05  0:34 ` [PATCH 7/9] x86/fpu: rename lazy restore functions to "register state valid" riel
2016-10-05  2:09   ` Andy Lutomirski
2016-10-07  9:46   ` [tip:x86/fpu] x86/fpu: Rename " tip-bot for Rik van Riel
2016-10-05  0:34 ` [PATCH 8/9] x86/fpu: remove __fpregs_(de)activate riel
2016-10-05  2:10   ` Andy Lutomirski
2016-10-07  9:46   ` [tip:x86/fpu] x86/fpu: Remove __fpregs_(de)activate() tip-bot for Rik van Riel
2016-10-05  0:34 ` riel [this message]
2016-10-07  9:47   ` [tip:x86/fpu] x86/fpu: Split old & new FPU code paths tip-bot for Rik van Riel

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