From: Anton Blanchard <anton@samba.org>
To: benh@kernel.crashing.org, paulus@samba.org, michael@ellerman.id.au
Cc: linuxppc-dev@lists.ozlabs.org
Subject: [PATCH] powerpc: pseries: Round up MSI-X requests
Date: Mon, 4 Jun 2012 09:15:45 +1000 [thread overview]
Message-ID: <20120604091545.03ce738b@kryten> (raw)
The pseries firmware currently refuses any non power of two MSI-X
request. Unfortunately most network drivers end up asking for that
because they want a power of two for RX queues and one or two extra
for everything else.
This patch rounds up the firmware request to the next power of two
if the quota allows it.
Signed-off-by: Anton Blanchard <anton@samba.org>
---
Index: linux-build/arch/powerpc/platforms/pseries/msi.c
===================================================================
--- linux-build.orig/arch/powerpc/platforms/pseries/msi.c 2012-06-03 20:49:29.082280031 +1000
+++ linux-build/arch/powerpc/platforms/pseries/msi.c 2012-06-04 09:06:55.909732276 +1000
@@ -402,6 +402,18 @@ static int rtas_setup_msi_irqs(struct pc
return -EINVAL;
/*
+ * Firmware currently refuse any non power of two allocation
+ * so we round up if the quota will allow it.
+ */
+ if (type == PCI_CAP_ID_MSIX) {
+ int m = roundup_pow_of_two(nvec);
+ int quota = msi_quota_for_device(pdev, m);
+
+ if (quota >= m)
+ nvec = m;
+ }
+
+ /*
* Try the new more explicit firmware interface, if that fails fall
* back to the old interface. The old interface is known to never
* return MSI-Xs.
next reply other threads:[~2012-06-03 23:15 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-03 23:15 Anton Blanchard [this message]
2012-06-04 6:43 ` [PATCH] powerpc: pseries: Round up MSI-X requests Michael Ellerman
2012-06-04 6:54 ` Benjamin Herrenschmidt
2012-06-05 2:47 ` Anton Blanchard
2012-06-13 5:18 ` Michael Ellerman
2012-06-13 5:25 ` 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=20120604091545.03ce738b@kryten \
--to=anton@samba.org \
--cc=benh@kernel.crashing.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=michael@ellerman.id.au \
--cc=paulus@samba.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).