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ARM: virt: simplify __hyp_stub_install epilog 

__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>
hifive-unleashed-5.1
Marc Zyngier 2013-01-04 17:44:15 +00:00 committed by Will Deacon
parent 6e484be1cc
commit d01723479e
1 changed files with 3 additions and 9 deletions
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12
arch/arm/kernel/hyp-stub.S
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@ -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: