From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Date: Fri, 4 Jul 2014 17:41:53 +0000 (+0200)
Subject: efi/arm64: Preserve FP/SIMD registers on UEFI runtime services calls
X-Git-Tag: omap-for-v3.17/fixes-against-rc2~174^2~25
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e15dd4949a937d8e8482f37f8fe493357417f203;p=pandora-kernel.git

efi/arm64: Preserve FP/SIMD registers on UEFI runtime services calls

According to the UEFI spec section 2.3.6.4, the use of FP/SIMD
instructions is allowed, and should adhere to the AAPCS64 calling
convention, which states that 'only the bottom 64 bits of each value
stored in registers v8-v15 need to be preserved' (section 5.1.2).

This applies equally to UEFI Runtime Services called by the kernel, so
make sure the FP/SIMD register file is preserved in this case. We do this
by enabling the wrappers for UEFI Runtime Services (CONFIG_EFI_RUNTIME_WRAPPERS)
and inserting calls to kernel_neon_begin()and kernel_neon_end() into
these wrappers.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
---

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