RE: [PATCH 2/3 v13] iommu/fsl: Add additional iommu attributesrequired by the PAMU driver.

From: Sethi Varun-B16395
Date: Tue Apr 23 2013 - 00:45:47 EST




> -----Original Message-----
> From: Wood Scott-B07421
> Sent: Tuesday, April 23, 2013 5:20 AM
> To: Sethi Varun-B16395
> Cc: joro@xxxxxxxxxx; iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; linuxppc-
> dev@xxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> galak@xxxxxxxxxxxxxxxxxxx; benh@xxxxxxxxxxxxxxxxxxx; Yoder Stuart-B08248;
> Sethi Varun-B16395
> Subject: Re: [PATCH 2/3 v13] iommu/fsl: Add additional iommu attributes
> required by the PAMU driver.
>
> On 04/22/2013 12:31:55 AM, Varun Sethi wrote:
> > Added the following domain attributes for the FSL PAMU driver:
> > 1. Added new iommu stash attribute, which allows setting of the
> > LIODN specific stash id parameter through IOMMU API.
> > 2. Added an attribute for enabling/disabling DMA to a particular
> > memory window.
> > 3. Added domain attribute to check for PAMUV1 specific constraints.
> >
> > Signed-off-by: Varun Sethi <Varun.Sethi@xxxxxxxxxxxxx>
> > ---
> > v13 changes:
> > - created a new file include/linux/fsl_pamu_stash.h for stash
> > attributes.
> > v12 changes:
> > - Moved PAMU specifc stash ids and structures to PAMU header file.
> > - no change in v11.
> > - no change in v10.
> > include/linux/fsl_pamu_stash.h | 39
> > +++++++++++++++++++++++++++++++++++++++
> > include/linux/iommu.h | 16 ++++++++++++++++
> > 2 files changed, 55 insertions(+), 0 deletions(-) create mode 100644
> > include/linux/fsl_pamu_stash.h
> >
> > diff --git a/include/linux/fsl_pamu_stash.h
> > b/include/linux/fsl_pamu_stash.h new file mode 100644 index
> > 0000000..caa1b21
> > --- /dev/null
> > +++ b/include/linux/fsl_pamu_stash.h
> > @@ -0,0 +1,39 @@
> > +/*
> > + * This program is free software; you can redistribute it and/or
> > modify
> > + * it under the terms of the GNU General Public License, version 2,
> > as
> > + * published by the Free Software Foundation.
> > + *
> > + * This program is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> > + * GNU General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU General Public License
> > + * along with this program; if not, write to the Free Software
> > + * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
> > 02110-1301, USA.
> > + *
> > + * Copyright (C) 2013 Freescale Semiconductor, Inc.
> > + *
> > + */
> > +
> > +#ifndef __FSL_PAMU_STASH_H
> > +#define __FSL_PAMU_STASH_H
> > +
> > +/* cache stash targets */
> > +enum pamu_stash_target {
> > + PAMU_ATTR_CACHE_L1 = 1,
> > + PAMU_ATTR_CACHE_L2,
> > + PAMU_ATTR_CACHE_L3,
> > +};
> > +
> > +/*
> > + * This attribute allows configuring stashig specific parameters
> > + * in the PAMU hardware.
> > + */
> > +
> > +struct pamu_stash_attribute {
> > + u32 cpu; /* cpu number */
> > + u32 cache; /* cache to stash to: L1,L2,L3 */
> > +};
> > +
> > +#endif /* __FSL_PAMU_STASH_H */
> > diff --git a/include/linux/iommu.h b/include/linux/iommu.h index
> > 2727810..c5dc2b9 100644
> > --- a/include/linux/iommu.h
> > +++ b/include/linux/iommu.h
> > @@ -57,10 +57,26 @@ struct iommu_domain {
> > #define IOMMU_CAP_CACHE_COHERENCY 0x1
> > #define IOMMU_CAP_INTR_REMAP 0x2 /* isolates device
> > intrs */
> >
> > +/*
> > + * Following constraints are specifc to PAMUV1:
>
> FSL_PAMUV1
>
> > + * -aperture must be power of 2, and naturally aligned
> > + * -number of windows must be power of 2, and address space size
> > + * of each window is determined by aperture size / # of windows
> > + * -the actual size of the mapped region of a window must be power
> > + * of 2 starting with 4KB and physical address must be naturally
> > + * aligned.
> > + * DOMAIN_ATTR_FSL_PAMUV1 corresponds to the above mentioned
> > contraints.
> > + * The caller can invoke iommu_domain_get_attr to check if the
> > underlying
> > + * iommu implementation supports these constraints.
> > + */
> > +
> > enum iommu_attr {
> > DOMAIN_ATTR_GEOMETRY,
> > DOMAIN_ATTR_PAGING,
> > DOMAIN_ATTR_WINDOWS,
> > + DOMAIN_ATTR_PAMU_STASH,
> > + DOMAIN_ATTR_PAMU_ENABLE,
> > + DOMAIN_ATTR_FSL_PAMUV1,
> > DOMAIN_ATTR_MAX,
>
> Please be consistent on whether "PAMU" gets an "FSL_" namespace prefix
> (I'd prefer that it does).
Submitted new version(v14) of the patch with updated attribute names.

-Varun

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