linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: Benjamin Herrenschmidt <bh40@calva.net>
To: linuxppc-dev@lists.linuxppc.org
Cc: Cort Dougan <cort@persephone.cs.nmt.edu>,
	Jesper Skov <jskov@cygnus.co.uk>
Subject: Re: Synchronization [was Re: The Magic Show: kernel_map() disappearing]
Date: Thu, 14 Jan 1999 14:27:52 +0100	[thread overview]
Message-ID: <19990114142752.015604@mail.mipsys.com> (raw)
In-Reply-To: <13981.45420.95483.559227@lassi.cygnus.co.uk>


On Thu, Jan 14, 1999, Jesper Skov <jskov@cygnus.co.uk> wrote:

>We would want to use eieio for drivers and such accessing their
>controller in a strict serialized manner. We would want to use sync
>for SMP related stuff since it ensures, well, synchronization between
>multiple CPUs wrt memory access.

And I'll add the usual warning: If the device is a PCI device and you
need to make sure that the write actually reached the device (for example
making sure the interrupt enable bits are set before re-enabling the
interrupts on the CPU), you should add a read from the same device (from
the same bus should be enough) to make sure tall the bridges in the path
to the device completed their write.
Remember that a write to PCI is usually a "posted write" and so is
asynchronous, regardless of eieio or sync's done on the CPU.

-- 
           E-Mail: <mailto:bh40@calva.net>
BenH.      Web   : <http://calvaweb.calvacom.fr/bh40/>





[[ This message was sent via the linuxppc-dev mailing list. Replies are ]]
[[ not forced back to the list, so be sure to  Cc linuxppc-dev  if your ]]
[[ reply is of general interest. To unsubscribe from linuxppc-dev, send ]]
[[ the message 'unsubscribe' to linuxppc-dev-request@lists.linuxppc.org ]]

  parent reply	other threads:[~1999-01-14 13:27 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <13980.23937.676502.388522@lassi.cygnus.co.uk>
     [not found] ` <Pine.LNX.3.96.990113130000.3632F-100000@persephone.cs.nmt.edu>
1999-01-14  8:57   ` Synchronization [was Re: The Magic Show: kernel_map() disappearing] Jesper Skov
1999-01-14  9:55     ` Jes Sorensen
1999-01-14 16:25       ` luther sven
1999-01-14 13:27     ` Benjamin Herrenschmidt [this message]
1999-01-14 19:46     ` Douglas Godfrey
1999-01-14 20:52     ` Alan Cox
1999-01-14 21:53       ` Cort Dougan
1999-01-15  1:38         ` Alan Cox
1999-01-15  8:26         ` Jesper Skov
1999-01-15  1:57       ` Paul Mackerras
1999-01-15  8:40         ` Jes Sorensen
1999-01-15 16:10         ` Alan Cox
1999-01-15 19:28           ` Cort Dougan
1999-01-16  1:00           ` Douglas Godfrey
1999-01-16  1:09             ` Synchronization [was Re: The Magic Show: kernel_map() Alan Cox
1999-01-15  8:50 Synchronization [was Re: The Magic Show: kernel_map() disappearing] Benjamin Herrenschmidt

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=19990114142752.015604@mail.mipsys.com \
    --to=bh40@calva.net \
    --cc=cort@persephone.cs.nmt.edu \
    --cc=jskov@cygnus.co.uk \
    --cc=linuxppc-dev@lists.linuxppc.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).