Re: [Qemu-devel] [PATCH 3/3] device_isolation: Support isolation on POWER p7ioc (IODA) bridges

[Alex Williamson <alex.williamson@redhat.com>]

On Wed, 2012-02-01 at 15:46 +1100, David Gibson wrote:
> This patch adds code to the code for the powernv platform to create
> and populate isolation groups on hardware using the p7ioc (aka IODA) PCI host
> bridge used on some IBM POWER systems.
> 
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> ---
>  arch/powerpc/platforms/powernv/pci-ioda.c |   18 ++++++++++++++++--
>  arch/powerpc/platforms/powernv/pci.h      |    6 ++++++
>  2 files changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
> index 5e155df..4648475 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> @@ -20,6 +20,7 @@
>  #include <linux/irq.h>
>  #include <linux/io.h>
>  #include <linux/msi.h>
> +#include <linux/device_isolation.h>
>  
>  #include <asm/sections.h>
>  #include <asm/io.h>
> @@ -877,6 +878,9 @@ static void __devinit pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe,
>  		set_iommu_table_base(&dev->dev, &pe->tce32_table);
>  		if (dev->subordinate)
>  			pnv_ioda_setup_bus_dma(pe, dev->subordinate);
> +#ifdef CONFIG_DEVICE_ISOLATION
> +		device_isolation_dev_add(&pe->di_group, &dev->dev);
> +#endif
>  	}
>  }
>  
> @@ -957,11 +961,21 @@ static void __devinit pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
>  	}
>  	iommu_init_table(tbl, phb->hose->node);
>  
> -	if (pe->pdev)
> +#ifdef CONFIG_DEVICE_ISOLATION
> +	BUG_ON(device_isolation_group_init(&pe->di_group, "ioda:rid%x-pe%x",
> +					   pe->rid, pe->pe_number) < 0);
> +#endif
> +
> +	if (pe->pdev) {
>  		set_iommu_table_base(&pe->pdev->dev, tbl);
> -	else
> +#ifdef CONFIG_DEVICE_ISOLATION
> +		device_isolation_dev_add(&pe->di_group, &pe->pdev->dev);
> +#endif
> +	} else
>  		pnv_ioda_setup_bus_dma(pe, pe->pbus);
>  

Blech, #ifdefs.

> +
> +
>  	return;
>   fail:
>  	/* XXX Failure: Try to fallback to 64-bit only ? */
> diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
> index 64ede1e..3e282b7 100644
> --- a/arch/powerpc/platforms/powernv/pci.h
> +++ b/arch/powerpc/platforms/powernv/pci.h
> @@ -1,6 +1,8 @@
>  #ifndef __POWERNV_PCI_H
>  #define __POWERNV_PCI_H
>  
> +#include <linux/device_isolation.h>
> +
>  struct pci_dn;
>  
>  enum pnv_phb_type {
> @@ -60,6 +62,10 @@ struct pnv_ioda_pe {
>  
>  	/* Link in list of PE#s */
>  	struct list_head	link;
> +
> +#ifdef CONFIG_DEVICE_ISOLATION
> +	struct device_isolation_group di_group;
> +#endif

Embedding the struct means we need to know the size, which means we
can't get rid of the #ifdef.  Probably better to use a pointer if we
don't mind adding a few bytes in the #ifndef case.  Thanks,

Alex

>  };
>  
>  struct pnv_phb {