Re: [PATCH 15/22] x86: Copy-n-paste arch_teardown_msi_irqs from msi.c to io_apic.c.

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

[-- Attachment #1: Type: text/plain, Size: 1111 bytes --]

On Wed, Oct 06, 2010 at 09:09:13PM -0400, Konrad Rzeszutek Wilk wrote:
> On Tue, Oct 05, 2010 at 11:07:36AM +0200, Thomas Gleixner wrote:
> > On Mon, 4 Oct 2010, Konrad Rzeszutek Wilk wrote:
> > 
> > > In preparation for non-privileged domains to disable PCI devices'
> > > MSI/MSIx, we need to augment arch_teardown_msi_irqs to make
> > > a call to the privileged domain (patch to follow).
> > 
> > Can't we find a more clever solution than just copying stuff around ?
> 
> Thanks for suggestion. Based on your idea, this is the patch I've rigged up.
> I've also included a different re-implementation of the next patch
> that would utilize this (x86-Introduce-x86_msi_ops). Tested successfully on x86.
> Cross-compiling on PPC, PPC64, and IA64 shows no failure.

But I did find that playing with 'make randconfig' where I got:
# CONFIG_PCI not set

produces interesting errors. So attached is the second patch, but
hardned against the case of building an X86 kernel without PCI support.

The patches are also available at:
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git devel/xen-pcifront-0.8



[-- Attachment #2: 0001-x86-Introduce-x86_msi_ops.patch --]
[-- Type: text/x-diff, Size: 4648 bytes --]

>From bb31ebf713b6651769876d49ea33fa08807c4be6 Mon Sep 17 00:00:00 2001
From: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Date: Wed, 6 Oct 2010 16:12:28 -0400
Subject: [PATCH] x86: Introduce x86_msi_ops

Introduce an x86 specific indirect mechanism to setup MSIs.
The MSI setup functions become function pointers in an x86_msi_ops
struct, that defaults to the implementation in io_apic.c and msi.c.

[v2: Use HAVE_DEFAULT_* knobs]
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
---
 arch/x86/include/asm/pci.h      |   33 +++++++++++++++++++++++++++++++--
 arch/x86/include/asm/x86_init.h |    9 +++++++++
 arch/x86/kernel/apic/io_apic.c  |    4 ++--
 arch/x86/kernel/x86_init.c      |    7 +++++++
 4 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h
index d395540..ca0437c 100644
--- a/arch/x86/include/asm/pci.h
+++ b/arch/x86/include/asm/pci.h
@@ -7,6 +7,7 @@
 #include <linux/string.h>
 #include <asm/scatterlist.h>
 #include <asm/io.h>
+#include <asm/x86_init.h>
 
 #ifdef __KERNEL__
 
@@ -94,8 +95,36 @@ static inline void early_quirks(void) { }
 
 extern void pci_iommu_alloc(void);
 
-/* MSI arch hook */
-#define arch_setup_msi_irqs arch_setup_msi_irqs
+#ifdef CONFIG_PCI_MSI
+/* MSI arch specific hooks */
+static inline int x86_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+	return x86_msi.setup_msi_irqs(dev, nvec, type);
+}
+
+static inline void x86_teardown_msi_irqs(struct pci_dev *dev)
+{
+	x86_msi.teardown_msi_irqs(dev);
+}
+
+static inline void x86_teardown_msi_irq(unsigned int irq)
+{
+	x86_msi.teardown_msi_irq(irq);
+}
+#define arch_setup_msi_irqs x86_setup_msi_irqs
+#define arch_teardown_msi_irqs x86_teardown_msi_irqs
+#define arch_teardown_msi_irq x86_teardown_msi_irq
+/* implemented in arch/x86/kernel/apic/io_apic. */
+int native_setup_msi_irqs(struct pci_dev *dev, int nvec, int type);
+void native_teardown_msi_irq(unsigned int irq);
+/* default to the implementation in drivers/lib/msi.c */
+#define HAVE_DEFAULT_MSI_TEARDOWN_IRQS
+void default_teardown_msi_irqs(struct pci_dev *dev);
+#else
+#define native_setup_msi_irqs		NULL
+#define native_teardown_msi_irq		NULL
+#define default_teardown_msi_irqs	NULL
+#endif
 
 #define PCI_DMA_BUS_IS_PHYS (dma_ops->is_phys)
 
diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index baa579c..64642ad 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -154,9 +154,18 @@ struct x86_platform_ops {
 	int (*i8042_detect)(void);
 };
 
+struct pci_dev;
+
+struct x86_msi_ops {
+	int (*setup_msi_irqs)(struct pci_dev *dev, int nvec, int type);
+	void (*teardown_msi_irq)(unsigned int irq);
+	void (*teardown_msi_irqs)(struct pci_dev *dev);
+};
+
 extern struct x86_init_ops x86_init;
 extern struct x86_cpuinit_ops x86_cpuinit;
 extern struct x86_platform_ops x86_platform;
+extern struct x86_msi_ops x86_msi;
 
 extern void x86_init_noop(void);
 extern void x86_init_uint_noop(unsigned int unused);
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 4c9b2b9..1bfc6d1 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -3533,7 +3533,7 @@ static int setup_msi_irq(struct pci_dev *dev, struct msi_desc *msidesc, int irq)
 	return 0;
 }
 
-int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+int native_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 {
 	unsigned int irq;
 	int ret, sub_handle;
@@ -3594,7 +3594,7 @@ error:
 	return ret;
 }
 
-void arch_teardown_msi_irq(unsigned int irq)
+void native_teardown_msi_irq(unsigned int irq)
 {
 	destroy_irq(irq);
 }
diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
index cd6da6b..ceb2911 100644
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -6,10 +6,12 @@
 #include <linux/init.h>
 #include <linux/ioport.h>
 #include <linux/module.h>
+#include <linux/pci.h>
 
 #include <asm/bios_ebda.h>
 #include <asm/paravirt.h>
 #include <asm/pci_x86.h>
+#include <asm/pci.h>
 #include <asm/mpspec.h>
 #include <asm/setup.h>
 #include <asm/apic.h>
@@ -99,3 +101,8 @@ struct x86_platform_ops x86_platform = {
 };
 
 EXPORT_SYMBOL_GPL(x86_platform);
+struct x86_msi_ops x86_msi = {
+	.setup_msi_irqs = native_setup_msi_irqs,
+	.teardown_msi_irq = native_teardown_msi_irq,
+	.teardown_msi_irqs = default_teardown_msi_irqs,
+};
-- 
1.7.0.4