All of lore.kernel.org
 help / color / mirror / Atom feed
From: Robin Murphy <robin.murphy@arm.com>
To: Marc Zyngier <maz@kernel.org>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Bjorn Helgaas <bhelgaas@google.com>
Cc: Frank Wunderlich <frank-w@public-files.de>,
	Thierry Reding <treding@nvidia.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Rob Herring <robh@kernel.org>, Will Deacon <will@kernel.org>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	Michael Kelley <mikelley@microsoft.com>,
	Wei Liu <wei.liu@kernel.org>,
	Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Ryder Lee <ryder.lee@mediatek.com>,
	Marek Vasut <marek.vasut+renesas@gmail.com>,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
	Michal Simek <michal.simek@xilinx.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-hyperv@vger.kernel.org, linux-tegra@vger.kernel.org,
	linux-mediatek@lists.infradead.org,
	linux-renesas-soc@vger.kernel.org, kernel-team@android.com
Subject: Re: [PATCH v2 12/15] PCI/MSI: Let PCI host bridges declare their reliance on MSI domains
Date: Tue, 23 Mar 2021 11:45:02 +0000	[thread overview]
Message-ID: <6a2eaa5d-1d83-159f-69e5-c9e0a00a7b50@arm.com> (raw)
In-Reply-To: <20210322184614.802565-13-maz@kernel.org>

On 2021-03-22 18:46, Marc Zyngier wrote:
> The new 'no_msi' attribute solves the problem of advertising the lack
> of MSI capability for host bridges that know for sure that there will
> be no MSI for their end-points.
> 
> However, there is a whole class of host bridges that cannot know
> whether MSIs will be provided or not, as they rely on other blocks
> to provide the MSI functionnality, using MSI domains.  This is
> the case for example on systems that use the ARM GIC architecture.
> 
> Introduce a new attribute ('msi_domain') indicating that implicit
> dependency, and use this property to set the NO_MSI flag when
> no MSI domain is found at probe time.
> 
> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
>   drivers/pci/probe.c | 2 +-
>   include/linux/pci.h | 1 +
>   2 files changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 146bd85c037e..bac9f69a06a8 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -925,7 +925,7 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
>   	device_enable_async_suspend(bus->bridge);
>   	pci_set_bus_of_node(bus);
>   	pci_set_bus_msi_domain(bus);
> -	if (bridge->no_msi)
> +	if (bridge->no_msi || (bridge->msi_domain && !bus->dev.msi_domain))
>   		bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
>   
>   	if (!parent)
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 48605cca82ae..d322d00db432 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -551,6 +551,7 @@ struct pci_host_bridge {
>   	unsigned int	preserve_config:1;	/* Preserve FW resource setup */
>   	unsigned int	size_windows:1;		/* Enable root bus sizing */
>   	unsigned int	no_msi:1;		/* Bridge has no MSI support */
> +	unsigned int	msi_domain:1;		/* Bridge wants MSI domain */

Aren't these really the same thing? Either way we're saying the bridge 
itself doesn't handle MSIs, it's just in one case we're effectively 
encoding a platform-specific assumption that an external domain won't be 
provided. I can't help wondering whether that distinction is really 
necessary...

Robin.

>   
>   	/* Resource alignment requirements */
>   	resource_size_t (*align_resource)(struct pci_dev *dev,
> 

WARNING: multiple messages have this Message-ID (diff)
From: Robin Murphy <robin.murphy@arm.com>
To: Marc Zyngier <maz@kernel.org>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Bjorn Helgaas <bhelgaas@google.com>
Cc: Frank Wunderlich <frank-w@public-files.de>,
	Thierry Reding <treding@nvidia.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Rob Herring <robh@kernel.org>, Will Deacon <will@kernel.org>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	Michael Kelley <mikelley@microsoft.com>,
	Wei Liu <wei.liu@kernel.org>,
	Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Ryder Lee <ryder.lee@mediatek.com>,
	Marek Vasut <marek.vasut+renesas@gmail.com>,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
	Michal Simek <michal.simek@xilinx.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-hyperv@vger.kernel.org, linux-tegra@vger.kernel.org,
	linux-mediatek@lists.infradead.org,
	linux-renesas-soc@vger.kernel.org, kernel-team@android.com
Subject: Re: [PATCH v2 12/15] PCI/MSI: Let PCI host bridges declare their reliance on MSI domains
Date: Tue, 23 Mar 2021 11:45:02 +0000	[thread overview]
Message-ID: <6a2eaa5d-1d83-159f-69e5-c9e0a00a7b50@arm.com> (raw)
In-Reply-To: <20210322184614.802565-13-maz@kernel.org>

On 2021-03-22 18:46, Marc Zyngier wrote:
> The new 'no_msi' attribute solves the problem of advertising the lack
> of MSI capability for host bridges that know for sure that there will
> be no MSI for their end-points.
> 
> However, there is a whole class of host bridges that cannot know
> whether MSIs will be provided or not, as they rely on other blocks
> to provide the MSI functionnality, using MSI domains.  This is
> the case for example on systems that use the ARM GIC architecture.
> 
> Introduce a new attribute ('msi_domain') indicating that implicit
> dependency, and use this property to set the NO_MSI flag when
> no MSI domain is found at probe time.
> 
> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
>   drivers/pci/probe.c | 2 +-
>   include/linux/pci.h | 1 +
>   2 files changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 146bd85c037e..bac9f69a06a8 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -925,7 +925,7 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
>   	device_enable_async_suspend(bus->bridge);
>   	pci_set_bus_of_node(bus);
>   	pci_set_bus_msi_domain(bus);
> -	if (bridge->no_msi)
> +	if (bridge->no_msi || (bridge->msi_domain && !bus->dev.msi_domain))
>   		bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
>   
>   	if (!parent)
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 48605cca82ae..d322d00db432 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -551,6 +551,7 @@ struct pci_host_bridge {
>   	unsigned int	preserve_config:1;	/* Preserve FW resource setup */
>   	unsigned int	size_windows:1;		/* Enable root bus sizing */
>   	unsigned int	no_msi:1;		/* Bridge has no MSI support */
> +	unsigned int	msi_domain:1;		/* Bridge wants MSI domain */

Aren't these really the same thing? Either way we're saying the bridge 
itself doesn't handle MSIs, it's just in one case we're effectively 
encoding a platform-specific assumption that an external domain won't be 
provided. I can't help wondering whether that distinction is really 
necessary...

Robin.

>   
>   	/* Resource alignment requirements */
>   	resource_size_t (*align_resource)(struct pci_dev *dev,
> 

_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek

WARNING: multiple messages have this Message-ID (diff)
From: Robin Murphy <robin.murphy@arm.com>
To: Marc Zyngier <maz@kernel.org>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Bjorn Helgaas <bhelgaas@google.com>
Cc: Frank Wunderlich <frank-w@public-files.de>,
	Thierry Reding <treding@nvidia.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Rob Herring <robh@kernel.org>, Will Deacon <will@kernel.org>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	Michael Kelley <mikelley@microsoft.com>,
	Wei Liu <wei.liu@kernel.org>,
	Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Ryder Lee <ryder.lee@mediatek.com>,
	Marek Vasut <marek.vasut+renesas@gmail.com>,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
	Michal Simek <michal.simek@xilinx.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-hyperv@vger.kernel.org, linux-tegra@vger.kernel.org,
	linux-mediatek@lists.infradead.org,
	linux-renesas-soc@vger.kernel.org, kernel-team@android.com
Subject: Re: [PATCH v2 12/15] PCI/MSI: Let PCI host bridges declare their reliance on MSI domains
Date: Tue, 23 Mar 2021 11:45:02 +0000	[thread overview]
Message-ID: <6a2eaa5d-1d83-159f-69e5-c9e0a00a7b50@arm.com> (raw)
In-Reply-To: <20210322184614.802565-13-maz@kernel.org>

On 2021-03-22 18:46, Marc Zyngier wrote:
> The new 'no_msi' attribute solves the problem of advertising the lack
> of MSI capability for host bridges that know for sure that there will
> be no MSI for their end-points.
> 
> However, there is a whole class of host bridges that cannot know
> whether MSIs will be provided or not, as they rely on other blocks
> to provide the MSI functionnality, using MSI domains.  This is
> the case for example on systems that use the ARM GIC architecture.
> 
> Introduce a new attribute ('msi_domain') indicating that implicit
> dependency, and use this property to set the NO_MSI flag when
> no MSI domain is found at probe time.
> 
> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
>   drivers/pci/probe.c | 2 +-
>   include/linux/pci.h | 1 +
>   2 files changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 146bd85c037e..bac9f69a06a8 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -925,7 +925,7 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
>   	device_enable_async_suspend(bus->bridge);
>   	pci_set_bus_of_node(bus);
>   	pci_set_bus_msi_domain(bus);
> -	if (bridge->no_msi)
> +	if (bridge->no_msi || (bridge->msi_domain && !bus->dev.msi_domain))
>   		bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
>   
>   	if (!parent)
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 48605cca82ae..d322d00db432 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -551,6 +551,7 @@ struct pci_host_bridge {
>   	unsigned int	preserve_config:1;	/* Preserve FW resource setup */
>   	unsigned int	size_windows:1;		/* Enable root bus sizing */
>   	unsigned int	no_msi:1;		/* Bridge has no MSI support */
> +	unsigned int	msi_domain:1;		/* Bridge wants MSI domain */

Aren't these really the same thing? Either way we're saying the bridge 
itself doesn't handle MSIs, it's just in one case we're effectively 
encoding a platform-specific assumption that an external domain won't be 
provided. I can't help wondering whether that distinction is really 
necessary...

Robin.

>   
>   	/* Resource alignment requirements */
>   	resource_size_t (*align_resource)(struct pci_dev *dev,
> 

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2021-03-23 11:45 UTC|newest]

Thread overview: 84+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-22 18:45 [PATCH v2 00/15] PCI/MSI: Getting rid of msi_controller, and other cleanups Marc Zyngier
2021-03-22 18:45 ` Marc Zyngier
2021-03-22 18:45 ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 01/15] PCI: tegra: Convert to MSI domains Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 02/15] PCI: rcar: Don't allocate extra memory for the MSI capture address Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 03/15] PCI: rcar: Convert to MSI domains Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 04/15] PCI: xilinx: Don't allocate extra memory for the MSI capture address Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-24 12:35   ` Bharat Kumar Gogada
2021-03-24 12:35     ` Bharat Kumar Gogada
2021-03-24 12:35     ` Bharat Kumar Gogada
2021-03-24 12:55     ` Marc Zyngier
2021-03-24 12:55       ` Marc Zyngier
2021-03-24 12:55       ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 05/15] PCI: xilinx: Convert to MSI domains Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-24 12:42   ` Bharat Kumar Gogada
2021-03-24 12:42     ` Bharat Kumar Gogada
2021-03-24 12:42     ` Bharat Kumar Gogada
2021-03-24 13:15     ` Marc Zyngier
2021-03-24 13:15       ` Marc Zyngier
2021-03-24 13:15       ` Marc Zyngier
2021-03-24 13:56       ` Bharat Kumar Gogada
2021-03-24 13:56         ` Bharat Kumar Gogada
2021-03-24 13:56         ` Bharat Kumar Gogada
2021-03-24 14:45         ` Marc Zyngier
2021-03-24 14:45           ` Marc Zyngier
2021-03-24 14:45           ` Marc Zyngier
2021-03-25  4:13           ` Bharat Kumar Gogada
2021-03-25  4:13             ` Bharat Kumar Gogada
2021-03-25  4:13             ` Bharat Kumar Gogada
2021-03-22 18:46 ` [PATCH v2 06/15] PCI: hv: Drop msi_controller structure Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 07/15] PCI/MSI: Drop use of msi_controller from core code Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 08/15] PCI/MSI: Kill msi_controller structure Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 09/15] PCI/MSI: Kill default_teardown_msi_irqs() Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 10/15] PCI/MSI: Let PCI host bridges declare their lack of MSI handling Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 11/15] PCI: mediatek: Advertise " Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 12/15] PCI/MSI: Let PCI host bridges declare their reliance on MSI domains Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-23 11:45   ` Robin Murphy [this message]
2021-03-23 11:45     ` Robin Murphy
2021-03-23 11:45     ` Robin Murphy
2021-03-23 18:09     ` Marc Zyngier
2021-03-23 18:09       ` Marc Zyngier
2021-03-23 18:09       ` Marc Zyngier
2021-03-23 19:04       ` Robin Murphy
2021-03-23 19:04         ` Robin Murphy
2021-03-23 19:04         ` Robin Murphy
2021-03-24 13:19       ` Lorenzo Pieralisi
2021-03-24 13:19         ` Lorenzo Pieralisi
2021-03-24 13:19         ` Lorenzo Pieralisi
2021-03-24 16:11         ` Marc Zyngier
2021-03-24 16:11           ` Marc Zyngier
2021-03-24 16:11           ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 13/15] PCI/MSI: Make pci_host_common_probe() declare its " Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 14/15] PCI/MSI: Document the various ways of ending up with NO_MSI Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 15/15] PCI: Refactor HT advertising of NO_MSI flag Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier
2021-03-22 18:46   ` Marc Zyngier

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=6a2eaa5d-1d83-159f-69e5-c9e0a00a7b50@arm.com \
    --to=robin.murphy@arm.com \
    --cc=bhelgaas@google.com \
    --cc=frank-w@public-files.de \
    --cc=haiyangz@microsoft.com \
    --cc=jonathanh@nvidia.com \
    --cc=kernel-team@android.com \
    --cc=kys@microsoft.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-hyperv@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mediatek@lists.infradead.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=linux-renesas-soc@vger.kernel.org \
    --cc=linux-tegra@vger.kernel.org \
    --cc=lorenzo.pieralisi@arm.com \
    --cc=marek.vasut+renesas@gmail.com \
    --cc=maz@kernel.org \
    --cc=michal.simek@xilinx.com \
    --cc=mikelley@microsoft.com \
    --cc=paul.walmsley@sifive.com \
    --cc=robh@kernel.org \
    --cc=ryder.lee@mediatek.com \
    --cc=sthemmin@microsoft.com \
    --cc=tglx@linutronix.de \
    --cc=thierry.reding@gmail.com \
    --cc=treding@nvidia.com \
    --cc=wei.liu@kernel.org \
    --cc=will@kernel.org \
    --cc=yoshihiro.shimoda.uh@renesas.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.