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From: Leon Romanovsky <leon@kernel.org>
To: Megha Dey <megha.dey@intel.com>
Cc: tglx@linutronix.de, linux-kernel@vger.kernel.org,
	dave.jiang@intel.com, ashok.raj@intel.com, kevin.tian@intel.com,
	dwmw@amazon.co.uk, x86@kernel.org, tony.luck@intel.com,
	dan.j.williams@intel.com, jgg@mellanox.com, kvm@vger.kernel.org,
	iommu@lists.linux-foundation.org, alex.williamson@redhat.com,
	bhelgaas@google.com, maz@kernel.org, linux-pci@vger.kernel.org,
	baolu.lu@linux.intel.com, ravi.v.shankar@intel.com
Subject: Re: [PATCH 11/12] platform-msi: Add platform check for subdevice irq domain
Date: Mon, 8 Feb 2021 10:21:48 +0200	[thread overview]
Message-ID: <20210208082148.GA20265@unreal> (raw)
In-Reply-To: <1612385805-3412-12-git-send-email-megha.dey@intel.com>

On Wed, Feb 03, 2021 at 12:56:44PM -0800, Megha Dey wrote:
> From: Lu Baolu <baolu.lu@linux.intel.com>
>
> The pci_subdevice_msi_create_irq_domain() should fail if the underlying
> platform is not able to support IMS (Interrupt Message Storage). Otherwise,
> the isolation of interrupt is not guaranteed.
>
> For x86, IMS is only supported on bare metal for now. We could enable it
> in the virtualization environments in the future if interrupt HYPERCALL
> domain is supported or the hardware has the capability of interrupt
> isolation for subdevices.
>
> Cc: David Woodhouse <dwmw@amazon.co.uk>
> Cc: Leon Romanovsky <leon@kernel.org>
> Cc: Kevin Tian <kevin.tian@intel.com>
> Suggested-by: Thomas Gleixner <tglx@linutronix.de>
> Link: https://lore.kernel.org/linux-pci/87pn4nk7nn.fsf@nanos.tec.linutronix.de/
> Link: https://lore.kernel.org/linux-pci/877dqrnzr3.fsf@nanos.tec.linutronix.de/
> Link: https://lore.kernel.org/linux-pci/877dqqmc2h.fsf@nanos.tec.linutronix.de/
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> Signed-off-by: Megha Dey <megha.dey@intel.com>
> ---
>  arch/x86/pci/common.c       | 74 +++++++++++++++++++++++++++++++++++++++++++++
>  drivers/base/platform-msi.c |  8 +++++
>  include/linux/msi.h         |  1 +
>  3 files changed, 83 insertions(+)
>
> diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
> index 3507f45..263ccf6 100644
> --- a/arch/x86/pci/common.c
> +++ b/arch/x86/pci/common.c
> @@ -12,6 +12,8 @@
>  #include <linux/init.h>
>  #include <linux/dmi.h>
>  #include <linux/slab.h>
> +#include <linux/iommu.h>
> +#include <linux/msi.h>
>
>  #include <asm/acpi.h>
>  #include <asm/segment.h>
> @@ -724,3 +726,75 @@ struct pci_dev *pci_real_dma_dev(struct pci_dev *dev)
>  	return dev;
>  }
>  #endif
> +
> +#ifdef CONFIG_DEVICE_MSI

Sorry for my naive question, but I see it in all your patches in this series
and wonder why did you wrap everything with ifdefs?.

All *.c code is wrapped with those ifdefs, which is hard to navigate and
unlikely to give any code/size optimization benefit if kernel is compiled
without CONFIG_DEVICE_MSI. The more common approach is to put those
ifdef in the public header files and leave to the compiler to drop not
called functions.

Thanks

  parent reply	other threads:[~2021-02-08  8:23 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-03 20:56 [PATCH 00/12] Introduce dev-msi and interrupt message store Megha Dey
2021-02-03 20:56 ` [PATCH 01/12] x86/irq: Add DEV_MSI allocation type Megha Dey
2021-02-03 20:56 ` [PATCH 02/12] x86/msi: Rename and rework pci_msi_prepare() to cover non-PCI MSI Megha Dey
2021-02-03 20:56 ` [PATCH 03/12] platform-msi: Provide default irq_chip:: Ack Megha Dey
2021-02-03 20:56 ` [PATCH 04/12] genirq/proc: Take buslock on affinity write Megha Dey
2021-02-03 20:56 ` [PATCH 05/12] genirq/msi: Provide and use msi_domain_set_default_info_flags() Megha Dey
2021-02-03 20:56 ` [PATCH 06/12] platform-msi: Add device MSI infrastructure Megha Dey
2021-02-03 20:56 ` [PATCH 07/12] irqdomain/msi: Provide msi_alloc/free_store() callbacks Megha Dey
2021-02-03 20:56 ` [PATCH 08/12] genirq: Set auxiliary data for an interrupt Megha Dey
2021-02-03 20:56 ` [PATCH 09/12] iommu/vt-d: Add DEV-MSI support Megha Dey
2021-02-03 20:56 ` [PATCH 10/12] iommu: Add capability IOMMU_CAP_VIOMMU_HINT Megha Dey
2021-02-03 20:56 ` [PATCH 11/12] platform-msi: Add platform check for subdevice irq domain Megha Dey
2021-02-04 12:14   ` Jason Gunthorpe
2021-02-04 13:22     ` Lu Baolu
2021-02-08  8:21   ` Leon Romanovsky [this message]
2021-02-09  0:36     ` Lu Baolu
2021-02-03 20:56 ` [PATCH 12/12] irqchip: Add IMS (Interrupt Message Store) driver Megha Dey

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