| From d01723479e6a6c70c83295f7847477a016d5e14a Mon Sep 17 00:00:00 2001 |
| From: Marc Zyngier <marc.zyngier@arm.com> |
| Date: Fri, 4 Jan 2013 17:44:15 +0000 |
| Subject: ARM: virt: simplify __hyp_stub_install epilog |
| |
| From: Marc Zyngier <marc.zyngier@arm.com> |
| |
| commit d01723479e6a6c70c83295f7847477a016d5e14a upstream. |
| |
| __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. |
| |
| 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> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| arch/arm/kernel/hyp-stub.S | 12 +++--------- |
| 1 file changed, 3 insertions(+), 9 deletions(-) |
| |
| --- 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: |
