From: Ard Biesheuvel <ardb@kernel.org>
To: linux-efi@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org,
Ard Biesheuvel <ardb@kernel.org>,
Johan Hovold <johan+linaro@kernel.org>,
Maximilian Luz <luzmaximilian@gmail.com>,
Nathan Chancellor <nathan@kernel.org>,
Steev Klimaszewski <steev@kali.org>,
Shawn Guo <shawn.guo@linaro.org>
Subject: [RFT PATCH 2/2] arm64: efi: Force use of SetVirtualAddressMap() on MS Surface
Date: Tue, 17 Jan 2023 15:27:18 +0100 [thread overview]
Message-ID: <20230117142718.564299-3-ardb@kernel.org> (raw)
In-Reply-To: <20230117142718.564299-1-ardb@kernel.org>
Qualcomm Snapdragon based Surface machines crash in the ResetSystem()
EFI runtime service if SetVirtualAddressMap() has not been called prior.
Unfortunately, SetVirtualAddressMap() itself crashes at boot time unless
the mapping being installed is a 1:1 mapping, as these firmware
implementations violate the EFI spec by accessing the new mapping before
SetVirtualAddressMap() completes.
Now that we have worked around the latter issue by always using a 1:1
map when the size of the VA space permits it, we can safely call
SetVirtualAddressMap() in such cases.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
drivers/firmware/efi/libstub/arm64.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/firmware/efi/libstub/arm64.c b/drivers/firmware/efi/libstub/arm64.c
index ff2d18c42ee74979..cc3757fc29bdda24 100644
--- a/drivers/firmware/efi/libstub/arm64.c
+++ b/drivers/firmware/efi/libstub/arm64.c
@@ -22,7 +22,8 @@ static bool system_needs_vamap(void)
* Ampere Altra machines crash in SetTime() if SetVirtualAddressMap()
* has not been called prior.
*/
- if (!type1_family || strcmp(type1_family, "Altra"))
+ if (!type1_family ||
+ (strcmp(type1_family, "Altra") && strcmp(type1_family, "Surface")))
return false;
efi_warn("Working around broken SetVirtualAddressMap()\n");
--
2.39.0
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next prev parent reply other threads:[~2023-01-17 14:28 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-17 14:27 [RFT PATCH 0/2] arm64: efi: Call SetVaMap() with a 1:1 mapping Ard Biesheuvel
2023-01-17 14:27 ` [RFT PATCH 1/2] arm64: efi: Prefer a flat virtual mapping of the runtime services Ard Biesheuvel
2023-01-17 14:27 ` Ard Biesheuvel [this message]
2023-01-17 15:20 ` [RFT PATCH 0/2] arm64: efi: Call SetVaMap() with a 1:1 mapping Ard Biesheuvel
2023-01-17 17:30 ` Nathan Chancellor
2023-01-18 7:56 ` Ard Biesheuvel
2023-01-18 15:26 ` Nathan Chancellor
2023-01-18 15:33 ` Ard Biesheuvel
2023-02-27 19:43 ` Darren Hart
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