On Tue, Sep 09, 2014 at 11:49:04PM +0100, Geoff Levand wrote: > Add the new hcall HVC_CALL_FUNC that allows execution of a function at EL2. > During CPU reset the CPU must be brought to the exception level it had on > entry to the kernel. The HVC_CALL_FUNC hcall will provide the mechanism > needed for this exception level switch. > > Signed-off-by: Geoff Levand <geoff at infradead.org> > --- > arch/arm64/include/asm/virt.h | 11 +++++++++++ > arch/arm64/kernel/hyp-stub.S | 10 ++++++++++ > 2 files changed, 21 insertions(+) [...] > diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S > index 9ab5f70..a21cf51 100644 > --- a/arch/arm64/kernel/hyp-stub.S > +++ b/arch/arm64/kernel/hyp-stub.S > @@ -75,7 +75,17 @@ el1_sync: > 1: cmp x10, #HVC_SET_VECTORS > b.ne 1f > msr vbar_el2, x0 > + b 2f > > +1: cmp x10, #HVC_CALL_FUNC > + b.ne 1f > + mov x29, lr > + mov lr, x0 > + mov x0, x1 > + mov x1, x2 > + mov x2, x3 > + blr lr > + mov lr, x29 Why are you clobbering x29? Will
