[v3,3/3] PCI: hv: Introduce hv_msi_entry
diff mbox series

Message ID 20200210033953.99692-4-boqun.feng@gmail.com
State New
Headers show
Series
  • PCI: hv: Generify pci-hyperv.c
Related show

Commit Message

Boqun Feng Feb. 10, 2020, 3:39 a.m. UTC
Add a new structure (hv_msi_entry), which is also defined in the TLFS,
to describe the msi entry for HVCALL_RETARGET_INTERRUPT. The structure
is needed because its layout may be different from architecture to
architecture.

Also add a new generic interface hv_set_msi_entry_from_desc() to allow
different archs to set the msi entry from msi_desc.

No functional change, only preparation for the future support of virtual
PCI on non-x86 architectures.

Signed-off-by: Boqun Feng (Microsoft) <boqun.feng@gmail.com>
---
 arch/x86/include/asm/hyperv-tlfs.h  | 11 +++++++++--
 arch/x86/include/asm/mshyperv.h     |  8 ++++++++
 drivers/pci/controller/pci-hyperv.c |  3 +--
 3 files changed, 18 insertions(+), 4 deletions(-)

Comments

Dexuan Cui Feb. 13, 2020, 4:18 a.m. UTC | #1
> From: linux-hyperv-owner@vger.kernel.org
> <linux-hyperv-owner@vger.kernel.org> On Behalf Of Boqun Feng
> diff --git a/arch/x86/include/asm/hyperv-tlfs.h
> b/arch/x86/include/asm/hyperv-tlfs.h
> 
> +union hv_msi_entry {
> +	u64 as_uint64;
> +	struct {
> +		u32 address;
> +		u32 data;
> +	} __packed;
> +};

Just a small thing: should we move the __packed to after the "}" of
the union hv_msi_entry ?

Reviewed-by: Dexuan Cui <decui@microsoft.com>
Boqun Feng Feb. 13, 2020, 7:14 a.m. UTC | #2
On Thu, Feb 13, 2020 at 04:18:01AM +0000, Dexuan Cui wrote:
> > From: linux-hyperv-owner@vger.kernel.org
> > <linux-hyperv-owner@vger.kernel.org> On Behalf Of Boqun Feng
> > diff --git a/arch/x86/include/asm/hyperv-tlfs.h
> > b/arch/x86/include/asm/hyperv-tlfs.h
> > 
> > +union hv_msi_entry {
> > +	u64 as_uint64;
> > +	struct {
> > +		u32 address;
> > +		u32 data;
> > +	} __packed;
> > +};
> 
> Just a small thing: should we move the __packed to after the "}" of
> the union hv_msi_entry ?
> 

Actually, in TLFS header, it's common to put the "__packed" inside the
union, rather than after the union. It makes sense because union is
different than struct: the alignment requirement of a union is already
decided by the "as_*" member, so no need for "__packed" attribute.

> Reviewed-by: Dexuan Cui <decui@microsoft.com>

Thanks!

Regards,
Boqun
Dexuan Cui Feb. 13, 2020, 8:05 a.m. UTC | #3
> From: Boqun Feng <boqun.feng@gmail.com>
> Sent: Wednesday, February 12, 2020 11:14 PM
> 
> On Thu, Feb 13, 2020 at 04:18:01AM +0000, Dexuan Cui wrote:
> > > From: linux-hyperv-owner@vger.kernel.org
> > > <linux-hyperv-owner@vger.kernel.org> On Behalf Of Boqun Feng
> > > diff --git a/arch/x86/include/asm/hyperv-tlfs.h
> > > b/arch/x86/include/asm/hyperv-tlfs.h
> > >
> > > +union hv_msi_entry {
> > > +	u64 as_uint64;
> > > +	struct {
> > > +		u32 address;
> > > +		u32 data;
> > > +	} __packed;
> > > +};
> >
> > Just a small thing: should we move the __packed to after the "}" of
> > the union hv_msi_entry ?
> >
> 
> Actually, in TLFS header, it's common to put the "__packed" inside the
> union, rather than after the union. It makes sense because union is
> different than struct: the alignment requirement of a union is already
> decided by the "as_*" member, so no need for "__packed" attribute.
> 
> Regards,
> Boqun

I see. Thanks for the explanation!

Thanks,
-- Dexuan

Patch
diff mbox series

diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index a0b6a88d2f05..29336574d0bc 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -913,11 +913,18 @@  struct hv_partition_assist_pg {
 	u32 tlb_lock_count;
 };
 
+union hv_msi_entry {
+	u64 as_uint64;
+	struct {
+		u32 address;
+		u32 data;
+	} __packed;
+};
+
 struct hv_interrupt_entry {
 	u32 source;			/* 1 for MSI(-X) */
 	u32 reserved1;
-	u32 address;
-	u32 data;
+	union hv_msi_entry msi_entry;
 } __packed;
 
 /*
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 6b79515abb82..81fc30240122 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -4,6 +4,7 @@ 
 
 #include <linux/types.h>
 #include <linux/nmi.h>
+#include <linux/msi.h>
 #include <asm/io.h>
 #include <asm/hyperv-tlfs.h>
 #include <asm/nospec-branch.h>
@@ -240,6 +241,13 @@  bool hv_vcpu_is_preempted(int vcpu);
 static inline void hv_apic_init(void) {}
 #endif
 
+static inline void hv_set_msi_entry_from_desc(union hv_msi_entry *msi_entry,
+					      struct msi_desc *msi_desc)
+{
+	msi_entry->address = msi_desc->msg.address_lo;
+	msi_entry->data = msi_desc->msg.data;
+}
+
 #else /* CONFIG_HYPERV */
 static inline void hyperv_init(void) {}
 static inline void hyperv_setup_mmu_ops(void) {}
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 0d9b74503577..3f9b220c23ec 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -1170,8 +1170,7 @@  static void hv_irq_unmask(struct irq_data *data)
 	memset(params, 0, sizeof(*params));
 	params->partition_id = HV_PARTITION_ID_SELF;
 	params->int_entry.source = 1; /* MSI(-X) */
-	params->int_entry.address = msi_desc->msg.address_lo;
-	params->int_entry.data = msi_desc->msg.data;
+	hv_set_msi_entry_from_desc(&params->int_entry.msi_entry, msi_desc);
 	params->device_id = (hbus->hdev->dev_instance.b[5] << 24) |
 			   (hbus->hdev->dev_instance.b[4] << 16) |
 			   (hbus->hdev->dev_instance.b[7] << 8) |