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From: Jiang Liu <jiang.liu@linux.intel.com>
To: Thomas Gleixner <tglx@linutronix.de>,
	Joerg Roedel <joro@8bytes.org>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	Yinghai Lu <yinghai@kernel.org>, Borislav Petkov <bp@alien8.de>,
	x86@kernel.org, Jiang Liu <jiang.liu@linux.intel.com>,
	David Rientjes <rientjes@google.com>,
	HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>,
	Jan Beulich <JBeulich@suse.com>,
	Richard Weinberger <richard@nod.at>,
	Oren Twaig <oren@scalemp.com>
Cc: Tony Luck <tony.luck@intel.com>,
	linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
	Joerg Roedel <jroedel@suse.de>,
	"H. Peter Anvin" <hpa@linux.intel.com>,
	Ingo Molnar <mingo@kernel.org>
Subject: [Patch v2 01/16] iommu, x86: Restructure setup of the irq remapping feature
Date: Wed,  7 Jan 2015 15:31:28 +0800
Message-ID: <1420615903-28253-2-git-send-email-jiang.liu@linux.intel.com> (raw)
In-Reply-To: <1420615903-28253-1-git-send-email-jiang.liu@linux.intel.com>

From: Thomas Gleixner <tglx@linutronix.de>

enable_IR_x2apic() calls setup_irq_remapping_ops() which by default
installs the intel dmar remapping ops and then calls the amd iommu irq
remapping prepare callback to figure out whether we are running on an
AMD machine with irq remapping hardware.

Right after that it calls irq_remapping_prepare() which pointlessly
checks:
	if (!remap_ops || !remap_ops->prepare)
               return -ENODEV;
and then calls

    remap_ops->prepare()

which is silly in the AMD case as it got called from
setup_irq_remapping_ops() already a few microseconds ago.

Simplify this and just collapse everything into
irq_remapping_prepare().

The irq_remapping_prepare() remains still silly as it assigns blindly
the intel ops, but that's not scope of this patch.

The scope here is to move the preperatory work, i.e. memory
allocations out of the atomic section which is required to enable irq
remapping.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Borislav Petkov <bp@alien8.de>
Acked-by: Joerg Roedel <joro@8bytes.org>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20141205084147.232633738@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
 arch/x86/include/asm/irq_remapping.h |    2 --
 arch/x86/kernel/apic/apic.c          |    3 ---
 drivers/iommu/irq_remapping.c        |   19 +++++++------------
 3 files changed, 7 insertions(+), 17 deletions(-)

diff --git a/arch/x86/include/asm/irq_remapping.h b/arch/x86/include/asm/irq_remapping.h
index b7747c4c2cf2..f1b619e5a50d 100644
--- a/arch/x86/include/asm/irq_remapping.h
+++ b/arch/x86/include/asm/irq_remapping.h
@@ -33,7 +33,6 @@ struct irq_cfg;
 
 #ifdef CONFIG_IRQ_REMAP
 
-extern void setup_irq_remapping_ops(void);
 extern int irq_remapping_supported(void);
 extern void set_irq_remapping_broken(void);
 extern int irq_remapping_prepare(void);
@@ -60,7 +59,6 @@ void irq_remap_modify_chip_defaults(struct irq_chip *chip);
 
 #else  /* CONFIG_IRQ_REMAP */
 
-static inline void setup_irq_remapping_ops(void) { }
 static inline int irq_remapping_supported(void) { return 0; }
 static inline void set_irq_remapping_broken(void) { }
 static inline int irq_remapping_prepare(void) { return -ENODEV; }
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 71b8a6cb7f0e..36249c715da0 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1597,9 +1597,6 @@ void __init enable_IR_x2apic(void)
 	int ret, x2apic_enabled = 0;
 	int hardware_init_ret;
 
-	/* Make sure irq_remap_ops are initialized */
-	setup_irq_remapping_ops();
-
 	hardware_init_ret = irq_remapping_prepare();
 	if (hardware_init_ret && !x2apic_supported())
 		return;
diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c
index 89c4846683be..91d5884d3ed9 100644
--- a/drivers/iommu/irq_remapping.c
+++ b/drivers/iommu/irq_remapping.c
@@ -194,16 +194,6 @@ static __init int setup_irqremap(char *str)
 }
 early_param("intremap", setup_irqremap);
 
-void __init setup_irq_remapping_ops(void)
-{
-	remap_ops = &intel_irq_remap_ops;
-
-#ifdef CONFIG_AMD_IOMMU
-	if (amd_iommu_irq_ops.prepare() == 0)
-		remap_ops = &amd_iommu_irq_ops;
-#endif
-}
-
 void set_irq_remapping_broken(void)
 {
 	irq_remap_broken = 1;
@@ -222,9 +212,14 @@ int irq_remapping_supported(void)
 
 int __init irq_remapping_prepare(void)
 {
-	if (!remap_ops || !remap_ops->prepare)
-		return -ENODEV;
+	remap_ops = &intel_irq_remap_ops;
 
+#ifdef CONFIG_AMD_IOMMU
+	if (amd_iommu_irq_ops.prepare() == 0) {
+		remap_ops = &amd_iommu_irq_ops;
+		return 0;
+	}
+#endif
 	return remap_ops->prepare();
 }
 
-- 
1.7.10.4


  reply index

Thread overview: 56+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-07  7:31 [Patch v2 00/16] Refine IR initialization flow and fixes bugs related to X2APIC Jiang Liu
2015-01-07  7:31 ` Jiang Liu [this message]
2015-01-15 12:58   ` [tip:x86/apic] iommu, x86: Restructure setup of the irq remapping feature tip-bot for Thomas Gleixner
2015-01-07  7:31 ` [Patch v2 02/16] iommu/vt-d: Move iommu preparatory allocations to irq_remap_ops.prepare Jiang Liu
2015-01-15 12:58   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2015-01-07  7:31 ` [Patch v2 03/16] iommu/vt-d: Convert allocations to GFP_KERNEL Jiang Liu
2015-01-15 12:59   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2015-01-07  7:31 ` [Patch v2 04/16] x86/apic: Panic if kernel doesn't support x2apic but BIOS has enabled x2apic Jiang Liu
2015-01-15 12:59   ` [tip:x86/apic] x86/apic: Panic if kernel doesn' t " tip-bot for Jiang Liu
2015-01-07  7:31 ` [Patch v2 05/16] x86/apic: Kill useless variable x2apic_enabled in function enable_IR_x2apic() Jiang Liu
2015-01-15 12:59   ` [tip:x86/apic] " tip-bot for Jiang Liu
2015-01-07  7:31 ` [Patch v2 06/16] x86/apic: Correctly detect X2APIC status in function enable_IR() Jiang Liu
2015-01-15 13:00   ` [tip:x86/apic] " tip-bot for Jiang Liu
2015-01-07  7:31 ` [Patch v2 07/16] x86/apic: Refine enable_IR_x2apic() and related functions Jiang Liu
2015-01-15  9:24   ` Thomas Gleixner
2015-01-15 13:00   ` [tip:x86/apic] " tip-bot for Jiang Liu
2015-01-15 13:00   ` [tip:x86/apic] x86/apic: Handle XAPIC remap mode proper tip-bot for Jiang Liu
2015-01-07  7:31 ` [Patch v2 08/16] iommu/vt-d: Prepare for killing function irq_remapping_supported() Jiang Liu
2015-01-15 13:01   ` [tip:x86/apic] " tip-bot for Jiang Liu
2015-01-07  7:31 ` [Patch v2 09/16] iommu/vt-d: Allocate IRQ remapping data structures only for all IOMMUs Jiang Liu
2015-01-15 13:01   ` [tip:x86/apic] " tip-bot for Joerg Roedel
2015-01-07  7:31 ` [Patch v2 10/16] iommu/vt-d: Allow IR works in XAPIC mode though CPU works in X2APIC mode Jiang Liu
2015-01-15 13:01   ` [tip:x86/apic] " tip-bot for Jiang Liu
2015-01-07  7:31 ` [Patch v2 11/16] x86/apic: Only disable CPU x2apic mode when necessary Jiang Liu
2015-01-15 13:02   ` [tip:x86/apic] " tip-bot for Jiang Liu
2015-01-07  7:31 ` [Patch v2 12/16] iommu/amd: Check for irq-remap support amd_iommu_prepare() Jiang Liu
2015-01-15 13:02   ` [tip:x86/apic] " tip-bot for Joerg Roedel
2015-01-07  7:31 ` [Patch v2 13/16] iommu/irq_remapping: Kill function irq_remapping_supported() and related code Jiang Liu
2015-01-15 13:02   ` [tip:x86/apic] " tip-bot for Jiang Liu
2015-01-07  7:31 ` [Patch v2 14/16] iommu/irq_remapping: Refine function irq_remapping_prepare() for maintenance Jiang Liu
2015-01-15 13:03   ` [tip:x86/apic] " tip-bot for Jiang Liu
2015-01-07  7:31 ` [Patch v2 15/16] iommu/irq_remapping: Change variable disable_irq_remap to be static Jiang Liu
2015-01-15 13:03   ` [tip:x86/apic] " tip-bot for Jiang Liu
2015-01-07  7:31 ` [Patch v2 16/16] iommu/irq_remapping: Normailize the way to detect whether IR is enabled Jiang Liu
2015-01-15 13:03   ` [tip:x86/apic] " tip-bot for Jiang Liu
2015-01-09 12:03 ` [Patch v2 00/16] Refine IR initialization flow and fixes bugs related to X2APIC Joerg Roedel
  -- strict thread matches above, loose matches on Subject: below --
2014-12-05  8:48 [patch 0/5] x86/iommu: Bootup stage cleanups Thomas Gleixner
2014-12-05  8:48 ` [patch 1/5] x86, smpboot: Remove pointless preempt_disable() in native_smp_prepare_cpus() Thomas Gleixner
2014-12-05 23:25   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2014-12-19 14:02   ` tip-bot for Thomas Gleixner
2014-12-05  8:48 ` [patch 2/5] iommu, x86: Restructure setup of the irq remapping feature Thomas Gleixner
2014-12-05 23:25   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2014-12-05  8:48 ` [patch 3/5] iommu/vt-d: Move iommu preparatory allocations to irq_remap_ops.prepare Thomas Gleixner
2014-12-05 23:26   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2014-12-11  7:35     ` Yinghai Lu
2014-12-11 14:33       ` Jiang Liu
2014-12-11 17:57         ` Yinghai Lu
2014-12-11 20:30           ` Thomas Gleixner
2014-12-12  2:04             ` Yinghai Lu
2015-04-27 22:46               ` Yinghai Lu
2015-04-29  8:15                 ` Jiang Liu
2014-12-05  8:48 ` [patch 4/5] irqdomain: Revert gfp hackery Thomas Gleixner
2014-12-05 23:26   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2014-12-05  8:48 ` [patch 5/5] iommu/vt-d: Convert allocations to GFP_KERNEL Thomas Gleixner
2014-12-05 23:26   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2014-12-05 12:22 ` [patch 0/5] x86/iommu: Bootup stage cleanups Joerg Roedel

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