| Message ID | 20210305093958.187358-1-ardb@kernel.org |
|---|---|
| Headers | show |
| Series | use RT_PROPERTIES table to implement efi=novamap | expand |
Hello: This patch was applied to qcom/linux.git (refs/heads/for-next): On Fri, 5 Mar 2021 10:39:57 +0100 you wrote: > This patch addresses an oversight on my part when I implemented Linux > side support for the EFI RT properties table: SetVirtualAddressMap() is > itself a runtime service which is only callable at runtime to begin with, > and so the EFI stub should only call it if it is not marked as unsupported. > > This may be useful for the Snapdragon EFI based laptops, which already rely > on a special EFI driver to expose the correct DT based on metadata exposed > by EFI. These systems ship with a broken implementation of SetVirtualAddressMap, > which is currently being worked around by passing efi=novamap on the kernel. > command line. > > [...] Here is the summary with links: - [1/1] efi: stub: omit SetVirtualAddressMap() if marked unsupported in RT_PROP table https://git.kernel.org/qcom/c/9e9888a0fe97 You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html
This patch addresses an oversight on my part when I implemented Linux side support for the EFI RT properties table: SetVirtualAddressMap() is itself a runtime service which is only callable at runtime to begin with, and so the EFI stub should only call it if it is not marked as unsupported. This may be useful for the Snapdragon EFI based laptops, which already rely on a special EFI driver to expose the correct DT based on metadata exposed by EFI. These systems ship with a broken implementation of SetVirtualAddressMap, which is currently being worked around by passing efi=novamap on the kernel. command line. After applying this patch (which I intend to propose for backporting to 5.10), the same can be achieved by exposing a RT_PROP table that marks SetVAMap() as unsupported. And while at it, better mark the variable services as unsupported as well, since they don't work under Linux either. I'm open to extending this with a Linux specific override value kept in a EFI variable, so that platforms that cannot support DtbLoader are able to implement something similar. Cc: Jeffrey Hugo <jhugo@codeaurora.org>, Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Shawn Guo <shawn.guo@linaro.org> Cc: Rob Clark <robdclark@gmail.com> Cc: Leif Lindholm <leif@nuviainc.com> Cc: linux-arm-msm@vger.kernel.org Ard Biesheuvel (1): efi: stub: omit SetVirtualAddressMap() if marked unsupported in RT_PROP table drivers/firmware/efi/libstub/efi-stub.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)