[PATCH 3/6] ARM: virt: simplify __hyp_stub_install epilog
will.deacon at arm.com
Fri Jan 11 10:34:14 EST 2013
From: Marc Zyngier <marc.zyngier at 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 at vger.kernel.org>
Reviewed-by: Dave Martin <dave.martin at linaro.org>
Reported-by: Harry Liebel <harry.liebel at arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
Signed-off-by: Will Deacon <will.deacon at 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
@@ -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
- 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.
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