mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: yshi <yang.shi@windriver.com>
To: axboe@kernel.dk
Cc: linux-kernel <linux-kernel@vger.kernel.org>
Subject: [PATCH] Fix DMA access of block device in 64-bit kernel on some non-x86 systems with 4GB or upper 4GB memory
Date: Tue, 04 Mar 2008 17:34:19 +0800	[thread overview]
Message-ID: <47CD179B.3000806@windriver.com> (raw)

For some non-x86 systems with 4GB or upper 4GB memory,
we need increase the range of addresses that can be
used for direct DMA in 64-bit kernel.

Signed-off-by: Yang Shi <yang.shi@windriver.com>
---
b/block/blk-settings.c |    2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
---

--- a/block/blk-settings.c      2008-03-03 17:11:25.000000000 +0800
+++ b/block/blk-settings.c      2008-03-03 17:11:42.000000000 +0800
@@ -140,7 +140,7 @@ void blk_queue_bounce_limit(struct reque
       /* Assume anything <= 4GB can be handled by IOMMU.
          Actually some IOMMUs can handle everything, but I don't
          know of a way to test this here. */
-       if (b_pfn < (min_t(u64, 0xffffffff, BLK_BOUNCE_HIGH) >> 
PAGE_SHIFT))
+       if (b_pfn <= (min_t(u64, 0xffffffff, BLK_BOUNCE_HIGH) >> 
PAGE_SHIFT))
               dma = 1;
       q->bounce_pfn = max_low_pfn;
#else

             reply	other threads:[~2008-03-04  9:34 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-04  9:34 yshi [this message]
2008-03-04 10:14 ` Jens Axboe

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=47CD179B.3000806@windriver.com \
    --to=yang.shi@windriver.com \
    --cc=axboe@kernel.dk \
    --cc=linux-kernel@vger.kernel.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

Powered by JetHome