Re: [RFC,1/8] soc/fman: Add FMan MURAM support

Re: [RFC,1/8] soc/fman: Add FMan MURAM support

[Kumar Gala]

On Mar 11, 2015, at 12:07 AM, Igal.Liberman <igal.liberman@freescale.com> wrote:

> From: Igal Liberman <Igal.Liberman@freescale.com>
> 
> Add Frame Manager Multi-User RAM support.
> 
> Signed-off-by: Igal Liberman <Igal.Liberman@freescale.com>
> ---
> drivers/soc/fsl/fman/Kconfig            |    1 +
> drivers/soc/fsl/fman/Makefile           |    5 +-
> drivers/soc/fsl/fman/fm_muram.c         |  174 +++++++++++++++++++++++++++++++
> drivers/soc/fsl/fman/inc/fm_muram_ext.h |   98 +++++++++++++++++
> 4 files changed, 276 insertions(+), 2 deletions(-)
> create mode 100644 drivers/soc/fsl/fman/fm_muram.c
> create mode 100644 drivers/soc/fsl/fman/inc/fm_muram_ext.h
> 

use lib/genalloc instead of rheap

- k

RE: [RFC,1/8] soc/fman: Add FMan MURAM support

[Igal.Liberman]

Regards,
Igal Liberman.

> -----Original Message-----
> From: Kumar Gala [mailto:galak@kernel.crashing.org]
> Sent: Thursday, March 12, 2015 5:57 PM
> To: Liberman Igal-B31950
> Cc: linuxppc-dev@lists.ozlabs.org; netdev@vger.kernel.org; linux-
> kernel@vger.kernel.org; Wood Scott-B07421
> Subject: Re: [RFC,1/8] soc/fman: Add FMan MURAM support
> 
> 
> On Mar 11, 2015, at 12:07 AM, Igal.Liberman <igal.liberman@freescale.com>
> wrote:
> 
> > From: Igal Liberman <Igal.Liberman@freescale.com>
> >
> > Add Frame Manager Multi-User RAM support.
> >
> > Signed-off-by: Igal Liberman <Igal.Liberman@freescale.com>
> > ---
> > drivers/soc/fsl/fman/Kconfig            |    1 +
> > drivers/soc/fsl/fman/Makefile           |    5 +-
> > drivers/soc/fsl/fman/fm_muram.c         |  174
> +++++++++++++++++++++++++++++++
> > drivers/soc/fsl/fman/inc/fm_muram_ext.h |   98 +++++++++++++++++
> > 4 files changed, 276 insertions(+), 2 deletions(-) create mode 100644
> > drivers/soc/fsl/fman/fm_muram.c create mode 100644
> > drivers/soc/fsl/fman/inc/fm_muram_ext.h
> >
> 
> use lib/genalloc instead of rheap
> 

Hi Kumar,
I looked into lib/genalloc allocator.
As far as I see, the genalloc allocator doesn't allow to control the memory alignment when you allocate a chunk of memory.
Two important notes regarding MURAM memory:
- The allocated memory chunks should have specific alignment (might be different in each chunk).
- The allocations must be efficient, we don't want to "waste" MURAM due to alignment issues.

> - k

Re: [RFC,1/8] soc/fman: Add FMan MURAM support

[Scott Wood]

On Mon, 2015-04-20 at 03:58 -0500, Liberman Igal-B31950 wrote:
> 
> Regards,
> Igal Liberman.
> 
> > -----Original Message-----
> > From: Kumar Gala [mailto:galak@kernel.crashing.org]
> > Sent: Thursday, March 12, 2015 5:57 PM
> > To: Liberman Igal-B31950
> > Cc: linuxppc-dev@lists.ozlabs.org; netdev@vger.kernel.org; linux-
> > kernel@vger.kernel.org; Wood Scott-B07421
> > Subject: Re: [RFC,1/8] soc/fman: Add FMan MURAM support
> > 
> > 
> > On Mar 11, 2015, at 12:07 AM, Igal.Liberman <igal.liberman@freescale.com>
> > wrote:
> > 
> > > From: Igal Liberman <Igal.Liberman@freescale.com>
> > >
> > > Add Frame Manager Multi-User RAM support.
> > >
> > > Signed-off-by: Igal Liberman <Igal.Liberman@freescale.com>
> > > ---
> > > drivers/soc/fsl/fman/Kconfig            |    1 +
> > > drivers/soc/fsl/fman/Makefile           |    5 +-
> > > drivers/soc/fsl/fman/fm_muram.c         |  174
> > +++++++++++++++++++++++++++++++
> > > drivers/soc/fsl/fman/inc/fm_muram_ext.h |   98 +++++++++++++++++
> > > 4 files changed, 276 insertions(+), 2 deletions(-) create mode 100644
> > > drivers/soc/fsl/fman/fm_muram.c create mode 100644
> > > drivers/soc/fsl/fman/inc/fm_muram_ext.h
> > >
> > 
> > use lib/genalloc instead of rheap
> > 
> 
> Hi Kumar,
> I looked into lib/genalloc allocator.
> As far as I see, the genalloc allocator doesn't allow to control the memory alignment when you allocate a chunk of memory.
> Two important notes regarding MURAM memory:
> - The allocated memory chunks should have specific alignment (might be different in each chunk).
> - The allocations must be efficient, we don't want to "waste" MURAM due to alignment issues.

If the requirement is that allocations must be size-aligned, use
gen_pool_first_fit_order_align.  Otherwise, improve genalloc to do what
you need.

-Scott