1. Patchew
  2. linux
  3. [PATCH v11 0/7] PCI: EP: Add RC-to-EP doorbell with platform MSI controller
  4. View patch

[PATCH v11 3/7] PCI: endpoint: pci-ep-msi: Add MSI address/data pair mutable check

Frank Li posted 7 patches 1 year, 1 month ago
There is a newer version of this series
[PATCH v11 3/7] PCI: endpoint: pci-ep-msi: Add MSI address/data pair mutable check
Posted by Frank Li 1 year, 1 month ago 
Some MSI controller change address/data pair when irq_set_affinity().
Current PCI endpoint can't support this type MSI controller. So add flag
MSI_FLAG_MSG_IMMUTABLE in include/linux/msi.h, set this flags in ARM GIC
ITS MSI controller and check it when allocate doorbell.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
Change from v9 to v11
- new patch
---
 drivers/irqchip/irq-gic-v3-its-msi-parent.c | 1 +
 drivers/pci/endpoint/pci-ep-msi.c           | 8 ++++++++
 include/linux/msi.h                         | 2 ++
 3 files changed, 11 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3-its-msi-parent.c b/drivers/irqchip/irq-gic-v3-its-msi-parent.c
index 33e94cfc4d506..a34e9bf93f991 100644
--- a/drivers/irqchip/irq-gic-v3-its-msi-parent.c
+++ b/drivers/irqchip/irq-gic-v3-its-msi-parent.c
@@ -16,6 +16,7 @@
 
 #define ITS_MSI_FLAGS_SUPPORTED (MSI_GENERIC_FLAGS_MASK |	\
 				 MSI_FLAG_PCI_MSIX      |	\
+				 MSI_FLAG_MSG_IMMUTABLE |	\
 				 MSI_FLAG_MULTI_PCI_MSI)
 
 #ifdef CONFIG_PCI_MSI
diff --git a/drivers/pci/endpoint/pci-ep-msi.c b/drivers/pci/endpoint/pci-ep-msi.c
index b0a91fde202f3..1c157e0a81456 100644
--- a/drivers/pci/endpoint/pci-ep-msi.c
+++ b/drivers/pci/endpoint/pci-ep-msi.c
@@ -107,6 +107,14 @@ int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 num_db)
 		return -EINVAL;
 	}
 
+	if (!dom->msi_parent_ops)
+		return -EINVAL;
+
+	if (!(dom->msi_parent_ops->supported_flags & MSI_FLAG_MSG_IMMUTABLE)) {
+		dev_err(dev, "Can't support mutable address/data pair MSI controller\n");
+		return -EINVAL;
+	}
+
 	dev_set_msi_domain(dev, dom);
 
 	msg = kcalloc(num_db, sizeof(struct pci_epf_doorbell_msg), GFP_KERNEL);
diff --git a/include/linux/msi.h b/include/linux/msi.h
index b10093c4d00ea..d95d979e4747a 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -556,6 +556,8 @@ enum {
 	MSI_FLAG_PCI_MSIX_ALLOC_DYN	= (1 << 20),
 	/* PCI MSIs cannot be steered separately to CPU cores */
 	MSI_FLAG_NO_AFFINITY		= (1 << 21),
+	/* Address and data pair is mutable when irq_set_affinity() */
+	MSI_FLAG_MSG_IMMUTABLE		= (1 << 22),
 };
 
 /**

-- 
2.34.1
Re: [PATCH v11 3/7] PCI: endpoint: pci-ep-msi: Add MSI address/data pair mutable check
Posted by Thomas Gleixner 1 year, 1 month ago 
Frank!

On Mon, Dec 09 2024 at 12:48, Frank Li wrote:

> Some MSI controller change address/data pair when irq_set_affinity().
> Current PCI endpoint can't support this type MSI controller. So add flag
> MSI_FLAG_MSG_IMMUTABLE in include/linux/msi.h, set this flags in ARM GIC
> ITS MSI controller and check it when allocate doorbell.
>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
> Change from v9 to v11
> - new patch
> ---
>  drivers/irqchip/irq-gic-v3-its-msi-parent.c | 1 +
>  drivers/pci/endpoint/pci-ep-msi.c           | 8 ++++++++
>  include/linux/msi.h                         | 2 ++

This is not how it works and I explained that you to more than once in
the past.

The change to the interrupt code is standalone and has nothing to do
with PCI endpoint. The latter is just a user of this.

So this want's to be split into several patches:

   1) add the new flag and a helper function which checks for the flag.

   2) add the flag to GICv3 ITS with a proper explanation

   3) Check for it in the PCI endpoint code

>  
> +	if (!dom->msi_parent_ops)
> +		return -EINVAL;

irq_domain_is_msi_parent()

> +	if (!(dom->msi_parent_ops->supported_flags & MSI_FLAG_MSG_IMMUTABLE)) {

Want's a helper.

Thanks,

        tglx
Re: [PATCH v11 3/7] PCI: endpoint: pci-ep-msi: Add MSI address/data pair mutable check
Posted by Frank Li 1 year, 1 month ago 
On Mon, Dec 09, 2024 at 08:51:52PM +0100, Thomas Gleixner wrote:
> Frank!
>
> On Mon, Dec 09 2024 at 12:48, Frank Li wrote:
>
> > Some MSI controller change address/data pair when irq_set_affinity().
> > Current PCI endpoint can't support this type MSI controller. So add flag
> > MSI_FLAG_MSG_IMMUTABLE in include/linux/msi.h, set this flags in ARM GIC
> > ITS MSI controller and check it when allocate doorbell.
> >
> > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > ---
> > Change from v9 to v11
> > - new patch
> > ---
> >  drivers/irqchip/irq-gic-v3-its-msi-parent.c | 1 +
> >  drivers/pci/endpoint/pci-ep-msi.c           | 8 ++++++++
> >  include/linux/msi.h                         | 2 ++
>
> This is not how it works and I explained that you to more than once in
> the past.
>
> The change to the interrupt code is standalone and has nothing to do
> with PCI endpoint. The latter is just a user of this.
>
> So this want's to be split into several patches:
>
>    1) add the new flag and a helper function which checks for the flag.

msi.h have not included irqdomain.h. It needs a API in msi.c

+bool msi_domain_is_immutable(struct irq_domain *domain)
+{
+        if (!irq_domain_is_msi_parent(domain))
+                return false;
+
+        return domain->msi_parent_ops->supported_flags & MSI_FLAG_MSG_IMMUTABLE;
+}
+EXPORT_SYMBOL_GPL(msi_domain_is_immutable);

Is it okay?

Frank

>
>    2) add the flag to GICv3 ITS with a proper explanation
>
>    3) Check for it in the PCI endpoint code
>
> >
> > +	if (!dom->msi_parent_ops)
> > +		return -EINVAL;
>
> irq_domain_is_msi_parent()
>
> > +	if (!(dom->msi_parent_ops->supported_flags & MSI_FLAG_MSG_IMMUTABLE)) {
>
> Want's a helper.
>
> Thanks,
>
>         tglx
Re: [PATCH v11 3/7] PCI: endpoint: pci-ep-msi: Add MSI address/data pair mutable check
Posted by Frank Li 1 year, 1 month ago 
On Mon, Dec 09, 2024 at 08:51:52PM +0100, Thomas Gleixner wrote:
> Frank!
>
> On Mon, Dec 09 2024 at 12:48, Frank Li wrote:
>
> > Some MSI controller change address/data pair when irq_set_affinity().
> > Current PCI endpoint can't support this type MSI controller. So add flag
> > MSI_FLAG_MSG_IMMUTABLE in include/linux/msi.h, set this flags in ARM GIC
> > ITS MSI controller and check it when allocate doorbell.
> >
> > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > ---
> > Change from v9 to v11
> > - new patch
> > ---
> >  drivers/irqchip/irq-gic-v3-its-msi-parent.c | 1 +
> >  drivers/pci/endpoint/pci-ep-msi.c           | 8 ++++++++
> >  include/linux/msi.h                         | 2 ++
>
> This is not how it works and I explained that you to more than once in
> the past.

The below suggest is great and I will update at next version. But I want to
know where I lost this.

v10: https://lore.kernel.org/imx/20241204-ep-msi-v10-0-87c378dbcd6d@nxp.com/T/#m3060eeab5d5bac931db685d21755a827dfc7a8c7
Talk about MUTABLE or IMPUTABLE
v9: https://lore.kernel.org/imx/87v7w0s9a8.ffs@tglx/
Talk about need add a imputable flags

v8: https://lore.kernel.org/imx/20241116-ep-msi-v8-0-6f1f68ffd1bb@nxp.com/
v7: https://lore.kernel.org/imx/20241114-ep-msi-v7-0-d4ac7aafbd2c@nxp.com/
v6: https://lore.kernel.org/all/20241112-ep-msi-v6-0-45f9722e3c2a@nxp.com/
v5: https://lore.kernel.org/all/20241108-ep-msi-v5-0-a14951c0d007@nxp.com/
v4: https://lore.kernel.org/all/20241031-ep-msi-v4-0-717da2d99b28@nxp.com/
Have not found your comments at v4 - v8

v3: https://lore.kernel.org/all/20241015-ep-msi-v3-0-cedc89a16c1a@nxp.com/
Talk about
msi_get_virq()

Frank

>
> The change to the interrupt code is standalone and has nothing to do
> with PCI endpoint. The latter is just a user of this.
>
> So this want's to be split into several patches:
>
>    1) add the new flag and a helper function which checks for the flag.
>
>    2) add the flag to GICv3 ITS with a proper explanation
>
>    3) Check for it in the PCI endpoint code
>
> >
> > +	if (!dom->msi_parent_ops)
> > +		return -EINVAL;
>
> irq_domain_is_msi_parent()
>
> > +	if (!(dom->msi_parent_ops->supported_flags & MSI_FLAG_MSG_IMMUTABLE)) {
>
> Want's a helper.
>
> Thanks,
>
>         tglx

Patchew 2.1-devel-b67e4c2

© 2016 - 2026 Red Hat, Inc.