This is a note to let you know that I've just added the patch titled ARM: 8990/1: use VFP assembler mnemonics in register load/store macros to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arm-8990-1-use-vfp-assembler-mnemonics-in-register-l.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit dc9a1d3f5f7a9ccc20e367dcf333c920361e8056 Author: Stefan Agner <stefan@xxxxxxxx> Date: Thu Jul 9 11:19:17 2020 +0100 ARM: 8990/1: use VFP assembler mnemonics in register load/store macros commit ee440336e5ef977c397afdb72cbf9c6b8effc8ea upstream. The integrated assembler of Clang 10 and earlier do not allow to access the VFP registers through the coprocessor load/store instructions: <instantiation>:4:6: error: invalid operand for instruction LDC p11, cr0, [r10],#32*4 @ FLDMIAD r10!, {d0-d15} ^ This has been addressed with Clang 11 [0]. However, to support earlier versions of Clang and for better readability use of VFP assembler mnemonics still is preferred. Replace the coprocessor load/store instructions with explicit assembler mnemonics to accessing the floating point coprocessor registers. Use assembler directives to select the appropriate FPU version. This allows to build these macros with GNU assembler as well as with Clang's built-in assembler. [0] https://reviews.llvm.org/D59733 Link: https://github.com/ClangBuiltLinux/linux/issues/905 Signed-off-by: Stefan Agner <stefan@xxxxxxxx> Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx> Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/arm/include/asm/vfpmacros.h b/arch/arm/include/asm/vfpmacros.h index 628c336e8e3b..947ee5395e1f 100644 --- a/arch/arm/include/asm/vfpmacros.h +++ b/arch/arm/include/asm/vfpmacros.h @@ -19,23 +19,25 @@ @ read all the working registers back into the VFP .macro VFPFLDMIA, base, tmp + .fpu vfpv2 #if __LINUX_ARM_ARCH__ < 6 - LDC p11, cr0, [\base],#33*4 @ FLDMIAX \base!, {d0-d15} + fldmiax \base!, {d0-d15} #else - LDC p11, cr0, [\base],#32*4 @ FLDMIAD \base!, {d0-d15} + vldmia \base!, {d0-d15} #endif #ifdef CONFIG_VFPv3 + .fpu vfpv3 #if __LINUX_ARM_ARCH__ <= 6 ldr \tmp, =elf_hwcap @ may not have MVFR regs ldr \tmp, [\tmp, #0] tst \tmp, #HWCAP_VFPD32 - ldclne p11, cr0, [\base],#32*4 @ FLDMIAD \base!, {d16-d31} + vldmiane \base!, {d16-d31} addeq \base, \base, #32*4 @ step over unused register space #else VFPFMRX \tmp, MVFR0 @ Media and VFP Feature Register 0 and \tmp, \tmp, #MVFR0_A_SIMD_MASK @ A_SIMD field cmp \tmp, #2 @ 32 x 64bit registers? - ldcleq p11, cr0, [\base],#32*4 @ FLDMIAD \base!, {d16-d31} + vldmiaeq \base!, {d16-d31} addne \base, \base, #32*4 @ step over unused register space #endif #endif @@ -44,22 +46,23 @@ @ write all the working registers out of the VFP .macro VFPFSTMIA, base, tmp #if __LINUX_ARM_ARCH__ < 6 - STC p11, cr0, [\base],#33*4 @ FSTMIAX \base!, {d0-d15} + fstmiax \base!, {d0-d15} #else - STC p11, cr0, [\base],#32*4 @ FSTMIAD \base!, {d0-d15} + vstmia \base!, {d0-d15} #endif #ifdef CONFIG_VFPv3 + .fpu vfpv3 #if __LINUX_ARM_ARCH__ <= 6 ldr \tmp, =elf_hwcap @ may not have MVFR regs ldr \tmp, [\tmp, #0] tst \tmp, #HWCAP_VFPD32 - stclne p11, cr0, [\base],#32*4 @ FSTMIAD \base!, {d16-d31} + vstmiane \base!, {d16-d31} addeq \base, \base, #32*4 @ step over unused register space #else VFPFMRX \tmp, MVFR0 @ Media and VFP Feature Register 0 and \tmp, \tmp, #MVFR0_A_SIMD_MASK @ A_SIMD field cmp \tmp, #2 @ 32 x 64bit registers? - stcleq p11, cr0, [\base],#32*4 @ FSTMIAD \base!, {d16-d31} + vstmiaeq \base!, {d16-d31} addne \base, \base, #32*4 @ step over unused register space #endif #endif