Subject: Re: [PATCH 2/3 v13] iommu/fsl: Add additional iommu attributes required by the PAMU driver.

From: Scott Wood <[email-masked]>
Date: Mon, 22 Apr 2013 18:50:09 -0500

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.
>=20
> Signed-off-by: Varun Sethi <[email-masked]>
> ---
> 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 =20
> +++++++++++++++++++++++++++++++++++++++
>  include/linux/iommu.h          |   16 ++++++++++++++++
>  2 files changed, 55 insertions(+), 0 deletions(-)
>  create mode 100644 include/linux/fsl_pamu_stash.h
>=20
> diff --git a/include/linux/fsl_pamu_stash.h =20
> 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 =20
> modify
> + * it under the terms of the GNU General Public License, version 2, =20
> 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  =20
> 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 =3D 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 =20
> intrs */
>=20
> +/*
> + * 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 =20
> contraints.
> + * The caller can invoke iommu_domain_get_attr to check if the =20
> 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 =20
(I'd prefer that it does).

-Scott=