| Message ID | 20170217154429.5000-11-marc.zyngier@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 17 February 2017 at 15:44, Marc Zyngier <marc.zyngier@arm.com> wrote: > It is not really obvious why the restart address should be in r3 > when communicated to the hyp-stub. r1 should be perfectly adequate, > and consistent with the rest of the code. > > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> > --- > arch/arm/kernel/hyp-stub.S | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S > index 8301db963d83..8fa521bd63d2 100644 > --- a/arch/arm/kernel/hyp-stub.S > +++ b/arch/arm/kernel/hyp-stub.S > @@ -214,7 +214,7 @@ __hyp_stub_do_trap: > > 1: teq r0, #HVC_SOFT_RESTART > bne 1f > - bx r3 > + bx r1 > > 1: mov r0, #-1 > > @@ -258,10 +258,8 @@ ENTRY(__hyp_set_vectors) > ENDPROC(__hyp_set_vectors) > > ENTRY(__hyp_soft_restart) > - mov r3, r0 > mov r0, #HVC_SOFT_RESTART > __HVC(0) > - mov r0, r3 > ret lr > ENDPROC(__hyp_soft_restart) > /me confused. How does the address end up in r1?
On Sun, 19 Feb 2017 08:22:23 +0000 Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: > On 17 February 2017 at 15:44, Marc Zyngier <marc.zyngier@arm.com> wrote: > > It is not really obvious why the restart address should be in r3 > > when communicated to the hyp-stub. r1 should be perfectly adequate, > > and consistent with the rest of the code. > > > > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> > > --- > > arch/arm/kernel/hyp-stub.S | 4 +--- > > 1 file changed, 1 insertion(+), 3 deletions(-) > > > > diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S > > index 8301db963d83..8fa521bd63d2 100644 > > --- a/arch/arm/kernel/hyp-stub.S > > +++ b/arch/arm/kernel/hyp-stub.S > > @@ -214,7 +214,7 @@ __hyp_stub_do_trap: > > > > 1: teq r0, #HVC_SOFT_RESTART > > bne 1f > > - bx r3 > > + bx r1 > > > > 1: mov r0, #-1 > > > > @@ -258,10 +258,8 @@ ENTRY(__hyp_set_vectors) > > ENDPROC(__hyp_set_vectors) > > > > ENTRY(__hyp_soft_restart) > > - mov r3, r0 > > mov r0, #HVC_SOFT_RESTART > > __HVC(0) > > - mov r0, r3 > > ret lr > > ENDPROC(__hyp_soft_restart) > > > > /me confused. How does the address end up in r1? I'm now very confused too. I just gave it another go on my A7 platform, and it restarted just right, even if there is obviously junk in r1. Guess I'm just bloody lucky. Thanks for the heads up, I'll fix that for v2. M.
diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S index 8301db963d83..8fa521bd63d2 100644 --- a/arch/arm/kernel/hyp-stub.S +++ b/arch/arm/kernel/hyp-stub.S @@ -214,7 +214,7 @@ __hyp_stub_do_trap: 1: teq r0, #HVC_SOFT_RESTART bne 1f - bx r3 + bx r1 1: mov r0, #-1 @@ -258,10 +258,8 @@ ENTRY(__hyp_set_vectors) ENDPROC(__hyp_set_vectors) ENTRY(__hyp_soft_restart) - mov r3, r0 mov r0, #HVC_SOFT_RESTART __HVC(0) - mov r0, r3 ret lr ENDPROC(__hyp_soft_restart)
It is not really obvious why the restart address should be in r3 when communicated to the hyp-stub. r1 should be perfectly adequate, and consistent with the rest of the code. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> --- arch/arm/kernel/hyp-stub.S | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)