From: Jeff Kubascik <jeff.kubascik@dornerworks.com>
To: <xen-devel@lists.xenproject.org>
Cc: Stewart Hildebrand <Stewart.Hildebrand@dornerworks.com>,
Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>,
Stefano Stabellini <sstabellini@kernel.org>,
Julien Grall <julien@xen.org>
Subject: [Xen-devel] [PATCH v3 2/2] xen/arm: sign extend writes to TimerValue
Date: Wed, 11 Dec 2019 16:13:02 -0500 [thread overview]
Message-ID: <20191211211302.117395-3-jeff.kubascik@dornerworks.com> (raw)
In-Reply-To: <20191211211302.117395-1-jeff.kubascik@dornerworks.com>
Per the ARMv8 Reference Manual (ARM DDI 0487E.a), section D11.2.4
specifies that the values in the TimerValue view of the timers are
signed in standard two's complement form. When writing to the TimerValue
register, it should be signed extended as described by the equation
CompareValue = (Counter[63:0] + SignExtend(TimerValue))[63:0]
Signed-off-by: Jeff Kubascik <jeff.kubascik@dornerworks.com>
---
xen/arch/arm/vtimer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/xen/arch/arm/vtimer.c b/xen/arch/arm/vtimer.c
index 21b98ec20a..872181d9b6 100644
--- a/xen/arch/arm/vtimer.c
+++ b/xen/arch/arm/vtimer.c
@@ -211,7 +211,7 @@ static bool vtimer_cntp_tval(struct cpu_user_regs *regs, uint32_t *r,
}
else
{
- v->arch.phys_timer.cval = cntpct + *r;
+ v->arch.phys_timer.cval = cntpct + (uint64_t)(int32_t)*r;
if ( v->arch.phys_timer.ctl & CNTx_CTL_ENABLE )
{
v->arch.phys_timer.ctl &= ~CNTx_CTL_PENDING;
--
2.17.1
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
next prev parent reply other threads:[~2019-12-11 21:13 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-11 21:13 [Xen-devel] [PATCH v3 0/2] xen/arm: physical timer improvements Jeff Kubascik
2019-12-11 21:13 ` [Xen-devel] [PATCH v3 1/2] xen/arm: remove physical timer offset Jeff Kubascik
2019-12-18 14:20 ` Julien Grall
2020-01-17 21:24 ` Jeff Kubascik
2020-01-23 12:28 ` Julien Grall
2019-12-11 21:13 ` Jeff Kubascik [this message]
2019-12-18 14:24 ` [Xen-devel] [PATCH v3 2/2] xen/arm: sign extend writes to TimerValue Julien Grall
2020-01-17 21:29 ` Jeff Kubascik
2020-01-18 11:49 ` Julien Grall
2020-01-21 14:43 ` Jeff Kubascik
2020-01-16 21:25 ` [Xen-devel] [PATCH v3 0/2] xen/arm: physical timer improvements Julien Grall
2020-01-16 21:52 ` Jeff Kubascik
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=20191211211302.117395-3-jeff.kubascik@dornerworks.com \
--to=jeff.kubascik@dornerworks.com \
--cc=Stewart.Hildebrand@dornerworks.com \
--cc=Volodymyr_Babchuk@epam.com \
--cc=julien@xen.org \
--cc=sstabellini@kernel.org \
--cc=xen-devel@lists.xenproject.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.