Re: [PATCH 1/1] - increase acpi owner_id max

[Aaron Young <ayoung@google.engr.sgi.com>]

> 
> OK, I missed that.
> 
> Can you give us some idea of just how many SSDTs this machine loads?

  It depends. SGI SN configs can vary dramatically. We create a unique
  SSDT for each populated PCI slot. The previous 255 SSDT id maximum
  could theoretically be surpassed on machines with huge amounts of IO -
  although configs with that much IO are extremely rare. We were
  just trying to avoid any (future) configuration limitations.

> 
> Does it dynamically delete SSDTs also?

  Yes. Our SN hotplug driver will add or remove SSDTs from the system
  upon hotplugs/hotunplugs.

> 
> Thanks,
> Bob
> 
> 
> > -----Original Message-----
> > From: Aaron Young [mailto:ayoung@google.engr.sgi.com]
> > Sent: Friday, January 26, 2007 4:03 PM
> > To: Moore, Robert
> > Cc: John Keller; linux-acpi@vger.kernel.org; ayoung@sgi.com; linux-
> > ia64@vger.kernel.org; linux-kernel@vger.kernel.org; Alexey
> Starikovskiy;
> > Brown, Len
> > Subject: Re: [PATCH 1/1] - increase acpi owner_id max
> > 
> > >
> > > The OwnerId field within a namespace node is 8 bits, and this is the
> > > main constraint on the maximum OwnerId. You can't simply bump up the
> > > number of owner ids without changing this field.
> > 
> >   Isn't this accomplished with the mod to aclocal.h below - i.e.
> >   by making a acpi_owner_id a u16 instead of a u8?:
> > 
> >  -typedef u8 acpi_owner_id;
> >  -#define ACPI_OWNER_ID_MAX               0xFF
> >  +typedef u16 acpi_owner_id;
> >  +#define ACPI_OWNER_ID_MAX               0x3FF
> > 
> > >
> > > If we need more than 255 owner Ids, the width of this field will
> have to
> > > be increased, or we will need to use a pointer for the field in
> order to
> > > maintain a linked list of all nodes owned by a particular owner.
> > >
> > > Bob
> > >
> > > > -----Original Message-----
> > > > From: linux-acpi-owner@vger.kernel.org [mailto:linux-acpi-
> > > > owner@vger.kernel.org] On Behalf Of John Keller
> > > > Sent: Friday, January 26, 2007 2:40 PM
> > > > To: linux-acpi@vger.kernel.org
> > > > Cc: ayoung@sgi.com; linux-ia64@vger.kernel.org; linux-
> > > > kernel@vger.kernel.org; John Keller
> > > > Subject: [PATCH 1/1] - increase acpi owner_id max
> > > >
> > > > To support systems with large IO configurations,
> > > > this patch increases the number of available ACPI
> > > > owner ids to 1023.
> > > >
> > > > On SN platforms, we represent every populated root
> > > > bus slot with an ACPI SSDT table containing info
> > > > for every device and PPB attached to the slot.
> > > > Each SSDT requires a unique ACPI owner id.
> > > >
> > > > Signed-off-by: John Keller <jpk@sgi.com>
> > > > ---
> > > >
> > > >  drivers/acpi/utilities/utmisc.c |    6 +++---
> > > >  include/acpi/acconfig.h         |    4 ++--
> > > >  include/acpi/aclocal.h          |    4 ++--
> > > >  3 files changed, 7 insertions(+), 7 deletions(-)
> > > >
> > > >
> > > > Index: linux/drivers/acpi/utilities/utmisc.c
> > > >
> ===================================================================
> > > > --- linux.orig/drivers/acpi/utilities/utmisc.c	2007-01-25
> > > > 11:27:25.509259412 -0600
> > > > +++ linux/drivers/acpi/utilities/utmisc.c	2007-01-26
> > > 13:16:09.551081284 -
> > > > 0600
> > > > @@ -147,7 +147,7 @@ acpi_status acpi_ut_allocate_owner_id(ac
> > > >  				/*
> > > >  				 * Construct encoded ID from the index
> > > and bit
> > > > position
> > > >  				 *
> > > > -				 * Note: Last [j].k (bit 255) is never
> > > used and is
> > > > marked
> > > > +				 * Note: Last [j].k (bit 1023) is never
> > > used and
> > > > is marked
> > > >  				 * permanently allocated (prevents +1
> > > overflow)
> > > >  				 */
> > > >  				*owner_id =
> > > > @@ -175,7 +175,7 @@ acpi_status acpi_ut_allocate_owner_id(ac
> > > >  	 */
> > > >  	status = AE_OWNER_ID_LIMIT;
> > > >  	ACPI_ERROR((AE_INFO,
> > > > -		    "Could not allocate new OwnerId (255 max),
> > > > AE_OWNER_ID_LIMIT"));
> > > > +		    "Could not allocate new OwnerId (1023 max),
> > > > AE_OWNER_ID_LIMIT"));
> > > >
> > > >        exit:
> > > >  	(void)acpi_ut_release_mutex(ACPI_MTX_CACHES);
> > > > @@ -192,7 +192,7 @@ acpi_status acpi_ut_allocate_owner_id(ac
> > > >   *              control method or unloading a table. Either way,
> we
> > > would
> > > >   *              ignore any error anyway.
> > > >   *
> > > > - * DESCRIPTION: Release a table or method owner ID.  Valid IDs
> are 1
> > > -
> > > > 255
> > > > + * DESCRIPTION: Release a table or method owner ID.  Valid IDs
> are 1
> > > -
> > > > 1023
> > > >   *
> > > >
> > > >
> > >
> ************************************************************************
> > > **
> > > > ****/
> > > >
> > > > Index: linux/include/acpi/acconfig.h
> > > >
> ===================================================================
> > > > --- linux.orig/include/acpi/acconfig.h	2007-01-25
> > > 11:27:25.577267818 -
> > > > 0600
> > > > +++ linux/include/acpi/acconfig.h	2007-01-26 13:17:14.111002597
> > > -0600
> > > > @@ -111,9 +111,9 @@
> > > >
> > > >  #define ACPI_SYSMEM_REGION_WINDOW_SIZE  4096
> > > >
> > > > -/* owner_id tracking. 8 entries allows for 255 owner_ids */
> > > > +/* owner_id tracking. 32 entries allow for 1023 owner_ids */
> > > >
> > > > -#define ACPI_NUM_OWNERID_MASKS          8
> > > > +#define ACPI_NUM_OWNERID_MASKS		32
> > > >
> > > >
> > > >
> > >
> /***********************************************************************
> > > **
> > > > *****
> > > >   *
> > > > Index: linux/include/acpi/aclocal.h
> > > >
> ===================================================================
> > > > --- linux.orig/include/acpi/aclocal.h	2007-01-25
> 11:27:25.585268807 -
> > > > 0600
> > > > +++ linux/include/acpi/aclocal.h	2007-01-26 13:20:06.148115848
> > > -0600
> > > > @@ -122,8 +122,8 @@ static char *acpi_gbl_mutex_names[ACPI_N
> > > >
> > > >  /* Owner IDs are used to track namespace nodes for selective
> deletion
> > > */
> > > >
> > > > -typedef u8 acpi_owner_id;
> > > > -#define ACPI_OWNER_ID_MAX               0xFF
> > > > +typedef u16 acpi_owner_id;
> > > > +#define ACPI_OWNER_ID_MAX               0x3FF
> > > >
> > > >  /* This Thread ID means that the mutex is not in use (unlocked)
> */
> > > >
> > > > -
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