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Re: [PATCH v3 4/6] linux-user/elfload: Introduce MIPS GET_FEATURE_REG_EQ
From: |
Richard Henderson |
Subject: |
Re: [PATCH v3 4/6] linux-user/elfload: Introduce MIPS GET_FEATURE_REG_EQU() macro |
Date: |
Tue, 1 Dec 2020 17:15:24 -0600 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 |
On 12/1/20 1:28 PM, Philippe Mathieu-Daudé wrote:
> ISA features are usually denoted in read-only bits from
> CPU registers. Add the GET_FEATURE_REG_EQU() macro which
> checks if a CPU register has bits set to a specific value.
>
> Use the macro to check the 'Architecture Revision' level
> of the Config0 register, which is '2' when the Release 6
> ISA is implemented.
>
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
> linux-user/elfload.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/linux-user/elfload.c b/linux-user/elfload.c
> index b7c6d30723a..9c475fa5f70 100644
> --- a/linux-user/elfload.c
> +++ b/linux-user/elfload.c
> @@ -7,6 +7,7 @@
>
> #include "qemu.h"
> #include "disas/disas.h"
> +#include "qemu/bitops.h"
> #include "qemu/path.h"
> #include "qemu/queue.h"
> #include "qemu/guest-random.h"
> @@ -995,17 +996,25 @@ enum {
> #define GET_FEATURE_REG_SET(_reg, _mask, _hwcap) \
> do { if (cpu->env._reg & (_mask)) { hwcaps |= _hwcap; } } while (0)
>
> +#define GET_FEATURE_REG_EQU(_reg, _start, _length, _val, _hwcap) \
> + do { \
> + if (extract32(cpu->env._reg, (_start), (_length)) == (_val)) { \
> + hwcaps |= _hwcap; \
> + } \
> + } while (0)
> +
> static uint32_t get_elf_hwcap(void)
> {
> MIPSCPU *cpu = MIPS_CPU(thread_cpu);
> uint32_t hwcaps = 0;
>
> - GET_FEATURE_INSN(ISA_MIPS32R6 | ISA_MIPS64R6, HWCAP_MIPS_R6);
> + GET_FEATURE_REG_EQU(CP0_Config0, CP0C0_AR, 3, 2, HWCAP_MIPS_R6);
You still get the magic 3.
This is where hw/registerfields.h would come in handy. But that is certainly a
large change to mips' cpu.h. So I guess this is good enough for now.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
r~
- [PATCH v3 0/6] linux-user: Rework get_elf_hwcap() and support MIPS Loongson 2F/3E, Philippe Mathieu-Daudé, 2020/12/01
- [PATCH v3 1/6] linux-user/elfload: Move GET_FEATURE macro out of get_elf_hwcap() body, Philippe Mathieu-Daudé, 2020/12/01
- [PATCH v3 2/6] linux-user/elfload: Rename MIPS GET_FEATURE() as GET_FEATURE_INSN(), Philippe Mathieu-Daudé, 2020/12/01
- [PATCH v3 3/6] linux-user/elfload: Introduce MIPS GET_FEATURE_REG_SET() macro, Philippe Mathieu-Daudé, 2020/12/01
- [PATCH v3 4/6] linux-user/elfload: Introduce MIPS GET_FEATURE_REG_EQU() macro, Philippe Mathieu-Daudé, 2020/12/01
- Re: [PATCH v3 4/6] linux-user/elfload: Introduce MIPS GET_FEATURE_REG_EQU() macro,
Richard Henderson <=
- [PATCH v3 5/6] linux-user/elfload: Update HWCAP bits from linux 5.7, Philippe Mathieu-Daudé, 2020/12/01
- [PATCH v3 6/6] linux-user: Add support for MIPS Loongson 2F/3E, Philippe Mathieu-Daudé, 2020/12/01