[PATCH 4/4] ARM: opcodes: Opcode definitions for the Virtualization Extensions

[Nicolas Pitre]

On Thu, 15 Mar 2012, Dave Martin wrote:

> For now, this patch just adds a definition for the HVC instruction.
> More can be added here later, as needed.
> 
> Now that we have a real example of how to use the opcode injection
> macros properly, this patch also adds a cross-reference from the
> explanation in opcodes.h (since without an example, figuring out
> how to use the macros is not that easy).
> 
> Signed-off-by: Dave Martin <dave.martin at linaro.org>

Acked-by: Nicolas Pitre <nico at linaro.org>

Maybe this would be a good idea to document in one of the patch logs why 
you didn't go with the assembler macro route like it is done in 
unified.h for the various it instructions.

> ---
>  arch/arm/include/asm/opcodes-virt.h |   29 +++++++++++++++++++++++++++++
>  arch/arm/include/asm/opcodes.h      |    2 ++
>  2 files changed, 31 insertions(+), 0 deletions(-)
>  create mode 100644 arch/arm/include/asm/opcodes-virt.h
> 
> diff --git a/arch/arm/include/asm/opcodes-virt.h b/arch/arm/include/asm/opcodes-virt.h
> new file mode 100644
> index 0000000..b85665a
> --- /dev/null
> +++ b/arch/arm/include/asm/opcodes-virt.h
> @@ -0,0 +1,29 @@
> +/*
> + * opcodes-virt.h: Opcode definitions for the ARM virtualization extensions
> + * Copyright (C) 2012  Linaro Limited
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, write to the Free Software Foundation, Inc.,
> + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
> + */
> +#ifndef __ASM_ARM_OPCODES_VIRT_H
> +#define __ASM_ARM_OPCODES_VIRT_H
> +
> +#include <asm/opcodes.h>
> +
> +#define __HVC(imm16) __inst_arm_thumb32(				\
> +	0xE1400070 | (((imm16) & 0xFFF0) << 4) | ((imm16) & 0x000F),	\
> +	0xF7E08000 | (((imm16) & 0xF000) << 4) | ((imm16) & 0x0FFF)	\
> +)
> +
> +#endif /* ! __ASM_ARM_OPCODES_VIRT_H */
> diff --git a/arch/arm/include/asm/opcodes.h b/arch/arm/include/asm/opcodes.h
> index 50ef0be..89ff5b9 100644
> --- a/arch/arm/include/asm/opcodes.h
> +++ b/arch/arm/include/asm/opcodes.h
> @@ -193,6 +193,8 @@ extern asmlinkage unsigned int arm_check_condition(u32 opcode, u32 psr);
>   * specify the ARM and Thumb alternatives at the same time.  This ensures
>   * that the correct opcode gets emitted depending on the instruction set
>   * used for the kernel build.
> + *
> + * Look at opcodes-virt.h for an example of how to use these macros.
>   */
>  #include <linux/stringify.h>
>  
> -- 
> 1.7.4.1
> 
> 
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