From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 3/6] ARM: virt: simplify __hyp_stub_install epilog
Date: Fri, 11 Jan 2013 15:34:14 +0000 [thread overview]
Message-ID: <1357918457-20469-4-git-send-email-will.deacon@arm.com> (raw)
In-Reply-To: <1357918457-20469-1-git-send-email-will.deacon@arm.com>
From: Marc Zyngier <marc.zyngier@arm.com>
__hyp_stub_install duplicates quite a bit of safe_svcmode_maskall
by forcing the CPU back to SVC. This is unnecessary, as
safe_svcmode_maskall is called just after.
Furthermore, the way we build SPSR_hyp is buggy as we fail to mask
the interrupts, leading to interesting behaviours on TC2 + UEFI.
The fix is to simply remove this code and rely on safe_svcmode_maskall
to do the right thing.
Cc: <stable@vger.kernel.org>
Reviewed-by: Dave Martin <dave.martin@linaro.org>
Reported-by: Harry Liebel <harry.liebel@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
arch/arm/kernel/hyp-stub.S | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S
index 3c60256..1315c4c 100644
--- a/arch/arm/kernel/hyp-stub.S
+++ b/arch/arm/kernel/hyp-stub.S
@@ -120,7 +120,8 @@ ENTRY(__hyp_stub_install_secondary)
* Eventually, CPU-specific code might be needed -- assume not for now
*
* This code relies on the "eret" instruction to synchronize the
- * various coprocessor accesses.
+ * various coprocessor accesses. This is done when we switch to SVC
+ * (see safe_svcmode_maskall).
*/
@ Now install the hypervisor stub:
adr r7, __hyp_stub_vectors
@@ -155,14 +156,7 @@ THUMB( orr r7, #(1 << 30) ) @ HSCTLR.TE
1:
#endif
- bic r7, r4, #MODE_MASK
- orr r7, r7, #SVC_MODE
-THUMB( orr r7, r7, #PSR_T_BIT )
- msr spsr_cxsf, r7 @ This is SPSR_hyp.
-
- __MSR_ELR_HYP(14) @ msr elr_hyp, lr
- __ERET @ return, switching to SVC mode
- @ The boot CPU mode is left in r4.
+ bx lr @ The boot CPU mode is left in r4.
ENDPROC(__hyp_stub_install_secondary)
__hyp_stub_do_trap:
--
1.8.0
next prev parent reply other threads:[~2013-01-11 15:34 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-11 15:34 [PATCH 0/6] Random collection of hyp-boot fixes and updates Will Deacon
2013-01-11 15:34 ` [PATCH 1/6] ARM: virt: Avoid bx instruction for compatibility with <=ARMv4 Will Deacon
2013-01-11 15:34 ` [PATCH 2/6] ARM: virt: boot secondary CPUs through the right entry point Will Deacon
2013-01-11 15:34 ` Will Deacon [this message]
2013-01-11 15:34 ` [PATCH 4/6] ARM: virt: avoid clobbering lr when forcing svc mode Will Deacon
2013-01-11 15:34 ` [PATCH 5/6] ARM: virt: use PSR_N_BIT for detecting boot CPU mode mismatch Will Deacon
2013-01-11 15:34 ` [PATCH 6/6] ARM: virt: hide CONFIG_ARM_VIRT_EXT from user Will Deacon
2013-01-11 15:42 ` Christopher Covington
2013-01-11 16:43 ` Will Deacon
2013-01-11 17:22 ` Christopher Covington
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=1357918457-20469-4-git-send-email-will.deacon@arm.com \
--to=will.deacon@arm.com \
--cc=linux-arm-kernel@lists.infradead.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).