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* ARM: virt: simplify __hyp_stub_install epilogMarc Zyngier2013-01-101-9/+3
| | | | | | | | | | | | | | | | | | __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>
* ARM: virt: Avoid bx instruction for compatibility with <=ARMv4Dave Martin2013-01-101-3/+3
| | | | | | | | | | | | | | | Non-T variants of ARMv4 do not support the bx instruction. However, __hyp_stub_install is always called from the same instruction set used to build the bulk of the kernel, so bx should not be necessary. This patch uses the traditional "mov pc" instead of bx. Cc: <stable@vger.kernel.org> Signed-off-by: Dave Martin <dave.martin@linaro.org> [will: fixed up remaining bx instruction] Signed-off-by: Will Deacon <will.deacon@arm.com>
* ARM: virt: arch_timers: enable access to physical timersMarc Zyngier2012-09-191-0/+13
| | | | | | | If booting in HYP mode, it makes sense to enable the use of the physical timers, so the kernel can use them directly. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* ARM: zImage/virt: hyp mode entry support for the zImage loaderDave Martin2012-09-191-0/+18
| | | | | | | | | | | | | | | | | | The zImage loader needs to turn on the MMU in order to take advantage of caching while decompressing the zImage. Running this in hyp mode would require the LPAE pagetable format to be supported; to avoid this complexity, this patch switches out of hyp mode, and returns back to hyp mode just before booting the kernel. This implementation assumes that the Hyp mode view of memory and the PL1 view of memory are coherent, providing that the MMU and caches are off in both, as required by the boot protocol. The zImage decompression code must drain the write buffer on completion anyway, and entry into Hyp mode should flush any prefetch buffer, avoiding hazards associated with local write buffers and the pipeline. Signed-off-by: Dave Martin <dave.martin@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* ARM: virt: allow the kernel to be entered in HYP modeDave Martin2012-09-191-0/+192
This patch does two things: * Ensure that asynchronous aborts are masked at kernel entry. The bootloader should be masking these anyway, but this reduces the damage window just in case it doesn't. * Enter svc mode via exception return to ensure that CPU state is properly serialised. This does not matter when switching from an ordinary privileged mode ("PL1" modes in ARMv7-AR rev C parlance), but it potentially does matter when switching from a another privileged mode such as hyp mode. This should allow the kernel to boot safely either from svc mode or hyp mode, even if no support for use of the ARM Virtualization Extensions is built into the kernel. Signed-off-by: Dave Martin <dave.martin@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>