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From: Thomas Gleixner <tglx@linutronix.de>
To: Dave Jiang <dave.jiang@intel.com>,
	vkoul@kernel.org, megha.dey@intel.com, maz@kernel.org,
	bhelgaas@google.com, rafael@kernel.org,
	gregkh@linuxfoundation.org, hpa@zytor.com,
	alex.williamson@redhat.com, jacob.jun.pan@intel.com,
	ashok.raj@intel.com, jgg@mellanox.com, yi.l.liu@intel.com,
	baolu.lu@intel.com, kevin.tian@intel.com,
	sanjay.k.kumar@intel.com, tony.luck@intel.com,
	jing.lin@intel.com, dan.j.williams@intel.com,
	kwankhede@nvidia.com, eric.auger@redhat.com, parav@mellanox.com,
	jgg@mellanox.com, rafael@kernel.org, dave.hansen@intel.com,
	netanelg@mellanox.com, shahafs@mellanox.com,
	yan.y.zhao@linux.intel.com, pbonzini@redhat.com,
	samuel.ortiz@intel.com, mona.hossain@intel.com
Cc: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org,
	x86@kernel.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [PATCH RFC v2 03/18] irq/dev-msi: Create IR-DEV-MSI irq domain
Date: Wed, 22 Jul 2020 22:44:51 +0200
Message-ID: <87lfjbz3cs.fsf@nanos.tec.linutronix.de> (raw)
In-Reply-To: <159534735519.28840.10435935598386192252.stgit@djiang5-desk3.ch.intel.com>

Dave Jiang <dave.jiang@intel.com> writes:
> From: Megha Dey <megha.dey@intel.com>
>
> When DEV_MSI is enabled, the dev_msi_default_domain is updated to the
> base DEV-MSI irq  domain. If interrupt remapping is enabled, we create

s/we//

> a new IR-DEV-MSI irq domain and update the dev_msi_default domain to
> the same.
>
> For X86, introduce a new irq_alloc_type which will be used by the
> interrupt remapping driver.
>
> Reviewed-by: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Megha Dey <megha.dey@intel.com>
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  arch/x86/include/asm/hw_irq.h       |    1 +
>  arch/x86/kernel/apic/msi.c          |   12 ++++++
>  drivers/base/dev-msi.c              |   66 +++++++++++++++++++++++++++++++----
>  drivers/iommu/intel/irq_remapping.c |   11 +++++-
>  include/linux/intel-iommu.h         |    1 +
>  include/linux/irqdomain.h           |   11 ++++++
>  include/linux/msi.h                 |    3 ++

Why is this mixing generic code, x86 core code and intel specific driver
code? This is new functionality so:

      1) Provide the infrastructure
      2) Add support to architecture specific parts
      3) Enable it

> +
> +#ifdef CONFIG_DEV_MSI
> +int dev_msi_prepare(struct irq_domain *domain, struct device *dev,
> +			   int nvec, msi_alloc_info_t *arg)
> +{
> +	memset(arg, 0, sizeof(*arg));
> +
> +	arg->type = X86_IRQ_ALLOC_TYPE_DEV_MSI;
> +
> +	return 0;
> +}
> +#endif

What is this? Tons of new lines for taking up more space and not a
single comment.

> -static int dev_msi_prepare(struct irq_domain *domain, struct device *dev,
> +int __weak dev_msi_prepare(struct irq_domain *domain, struct device *dev,
>  			   int nvec, msi_alloc_info_t *arg)
>  {
>  	memset(arg, 0, sizeof(*arg));

Oh well. So every architecure which needs to override this and I assume
all which are eventually going to support it need to do the memset() in
their override.

       memset(arg,,,);
       arch_dev_msi_prepare();


> -	dev_msi_default_domain = msi_create_irq_domain(fn, &dev_msi_domain_info, parent);
> +	/*
> +	 * This initcall may come after remap code is initialized. Ensure that
> +	 * dev_msi_default domain is updated correctly.

What? No, this is a disgusting hack. Get your ordering straight, that's
not rocket science.

> +#ifdef CONFIG_IRQ_REMAP

IRQ_REMAP is x86 specific. Is this file x86 only or intended to be for
general use? If it's x86 only, then this should be clearly
documented. If not, then these x86'isms have no place here.

> +struct irq_domain *create_remap_dev_msi_irq_domain(struct irq_domain *parent,
> +						   const char *name)

So we have msi_create_irq_domain() and this is about dev_msi, right? So
can you please stick with a consistent naming scheme?

> +{
> +	struct fwnode_handle *fn;
> +	struct irq_domain *domain;
> +
> +	fn = irq_domain_alloc_named_fwnode(name);
> +	if (!fn)
> +		return NULL;
> +
> +	domain = msi_create_irq_domain(fn, &dev_msi_ir_domain_info, parent);
> +	if (!domain) {
> +		pr_warn("failed to initialize irqdomain for IR-DEV-MSI.\n");
> +		return ERR_PTR(-ENXIO);
> +	}
> +
> +	irq_domain_update_bus_token(domain, DOMAIN_BUS_PLATFORM_MSI);
> +
> +	if (!dev_msi_default_domain)
> +		dev_msi_default_domain = domain;

Can this be called several times? If so, then this lacks a comment. If
not, then this condition is useless.

Thanks,

        tglx

  parent reply index

Thread overview: 97+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-21 16:02 [PATCH RFC v2 00/18] Add VFIO mediated device support and DEV-MSI support for the idxd driver Dave Jiang
2020-07-21 16:02 ` [PATCH RFC v2 01/18] platform-msi: Introduce platform_msi_ops Dave Jiang
2020-07-21 16:02 ` [PATCH RFC v2 02/18] irq/dev-msi: Add support for a new DEV_MSI irq domain Dave Jiang
2020-07-21 16:13   ` Jason Gunthorpe
2020-07-22 16:50     ` Dey, Megha
2020-07-22 18:52   ` Marc Zyngier
2020-07-22 19:59     ` Jason Gunthorpe
2020-07-23  8:51       ` Marc Zyngier
2020-07-24  0:16         ` Jason Gunthorpe
2020-07-24  0:36           ` Thomas Gleixner
2020-08-05 19:18       ` Dey, Megha
2020-08-05 22:15         ` Jason Gunthorpe
2020-08-05 22:36           ` Dey, Megha
2020-08-05 22:53             ` Jason Gunthorpe
2020-08-06  0:13               ` Dey, Megha
2020-08-06  0:19                 ` Jason Gunthorpe
2020-08-06  0:32                   ` Dey, Megha
2020-08-06  0:46                     ` Jason Gunthorpe
2020-08-06 17:10                     ` Thomas Gleixner
2020-08-06 17:58                       ` Dey, Megha
2020-08-06 20:21                         ` Thomas Gleixner
2020-08-06 22:27                           ` Dey, Megha
2020-08-07  8:48                             ` Thomas Gleixner
2020-08-07 12:06                           ` Jason Gunthorpe
2020-08-07 12:38                             ` gregkh
2020-08-07 13:34                               ` Jason Gunthorpe
2020-08-07 16:47                                 ` Thomas Gleixner
2020-08-07 17:54                                   ` Dey, Megha
2020-08-07 18:39                                     ` Jason Gunthorpe
2020-08-07 20:31                                       ` Dey, Megha
2020-08-08 19:47                                     ` Thomas Gleixner
2020-08-10 21:46                                       ` Thomas Gleixner
2020-08-11  9:53                                         ` Thomas Gleixner
2020-08-11 18:46                                           ` Dey, Megha
2020-08-11 21:25                                             ` Thomas Gleixner
2020-08-11 18:39                                       ` Dey, Megha
2020-08-11 22:39                                         ` Thomas Gleixner
2020-08-07 15:22                             ` Thomas Gleixner
2020-08-05 18:55     ` Dey, Megha
2020-07-21 16:02 ` [PATCH RFC v2 03/18] irq/dev-msi: Create IR-DEV-MSI " Dave Jiang
2020-07-21 16:21   ` Jason Gunthorpe
2020-07-22 17:03     ` Dey, Megha
2020-07-22 17:33       ` Jason Gunthorpe
2020-07-22 20:44   ` Thomas Gleixner [this message]
2020-08-05 19:02     ` Dey, Megha
2020-07-21 16:02 ` [PATCH RFC v2 04/18] irq/dev-msi: Introduce APIs to allocate/free dev-msi interrupts Dave Jiang
2020-07-21 16:25   ` Jason Gunthorpe
2020-07-22 17:05     ` Dey, Megha
2020-07-22 17:35       ` Jason Gunthorpe
2020-08-05 20:19         ` Dey, Megha
2020-07-21 16:02 ` [PATCH RFC v2 05/18] dmaengine: idxd: add support for readonly config devices Dave Jiang
2020-07-21 16:02 ` [PATCH RFC v2 06/18] dmaengine: idxd: add interrupt handle request support Dave Jiang
2020-07-21 16:03 ` [PATCH RFC v2 07/18] dmaengine: idxd: add DEV-MSI support in base driver Dave Jiang
2020-07-21 16:03 ` [PATCH RFC v2 08/18] dmaengine: idxd: add device support functions in prep for mdev Dave Jiang
2020-07-21 16:03 ` [PATCH RFC v2 09/18] dmaengine: idxd: add basic mdev registration and helper functions Dave Jiang
2020-07-21 16:03 ` [PATCH RFC v2 10/18] dmaengine: idxd: add emulation rw routines Dave Jiang
2020-07-21 16:03 ` [PATCH RFC v2 11/18] dmaengine: idxd: prep for virtual device commands Dave Jiang
2020-07-21 16:03 ` [PATCH RFC v2 12/18] dmaengine: idxd: virtual device commands emulation Dave Jiang
2020-07-21 16:03 ` [PATCH RFC v2 13/18] dmaengine: idxd: ims setup for the vdcm Dave Jiang
2020-07-21 16:03 ` [PATCH RFC v2 14/18] dmaengine: idxd: add mdev type as a new wq type Dave Jiang
2020-07-21 16:03 ` [PATCH RFC v2 15/18] dmaengine: idxd: add dedicated wq mdev type Dave Jiang
2020-07-21 16:04 ` [PATCH RFC v2 16/18] dmaengine: idxd: add new wq state for mdev Dave Jiang
2020-07-21 16:04 ` [PATCH RFC v2 17/18] dmaengine: idxd: add error notification from host driver to mediated device Dave Jiang
2020-07-21 16:04 ` [PATCH RFC v2 18/18] dmaengine: idxd: add ABI documentation for mediated device support Dave Jiang
2020-07-21 16:28 ` [PATCH RFC v2 00/18] Add VFIO mediated device support and DEV-MSI support for the idxd driver Greg KH
2020-07-21 17:17   ` Dave Jiang
2020-07-21 21:35   ` Dan Williams
2020-07-21 16:45 ` Jason Gunthorpe
2020-07-21 18:00   ` Dave Jiang
2020-07-22 17:31     ` Dey, Megha
2020-07-22 18:16       ` Jason Gunthorpe
2020-07-21 23:54   ` Tian, Kevin
2020-07-24  0:19     ` Jason Gunthorpe
2020-08-06  1:22       ` Alex Williamson
2020-08-07 12:19         ` Jason Gunthorpe
2020-08-10  7:32           ` Tian, Kevin
2020-08-11 17:00             ` Alex Williamson
2020-08-12  1:58               ` Tian, Kevin
2020-08-12  2:36                 ` Alex Williamson
2020-08-12  3:35                   ` Tian, Kevin
2020-08-12  3:28             ` Jason Wang
2020-08-12  4:05               ` Tian, Kevin
2020-08-13  4:33                 ` Jason Wang
2020-08-13  5:26                   ` Tian, Kevin
2020-08-13  6:01                     ` Jason Wang
2020-08-14 13:23                       ` Jason Gunthorpe
2020-08-17  2:24                         ` Tian, Kevin
2020-08-14 13:35             ` Jason Gunthorpe
2020-08-17  2:12               ` Tian, Kevin
2020-08-18  0:43                 ` Jason Gunthorpe
2020-08-18  1:09                   ` Tian, Kevin
2020-08-18 11:50                     ` Jason Gunthorpe
2020-08-18 16:27                       ` Paolo Bonzini
2020-08-18 16:49                         ` Jason Gunthorpe
2020-08-18 17:05                           ` Paolo Bonzini
2020-08-18 17:18                             ` Jason Gunthorpe
2020-08-19  7:29                       ` Tian, Kevin

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