Re: [PATCH 02/18] arm64: Add syndrome information for trapped LD64B/ST64B{,V,V0}

[Mark Rutland <mark.rutland@arm.com>]

On Mon, Feb 10, 2025 at 06:41:33PM +0000, Marc Zyngier wrote:
> Provide the architected EC and ISS values for all the FEAT_LS64*
> instructions.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
>  arch/arm64/include/asm/esr.h | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
> index d1b1a33f9a8b0..d5c2fac21a16c 100644
> --- a/arch/arm64/include/asm/esr.h
> +++ b/arch/arm64/include/asm/esr.h
> @@ -20,7 +20,8 @@
>  #define ESR_ELx_EC_FP_ASIMD	UL(0x07)
>  #define ESR_ELx_EC_CP10_ID	UL(0x08)	/* EL2 only */
>  #define ESR_ELx_EC_PAC		UL(0x09)	/* EL2 and above */
> -/* Unallocated EC: 0x0A - 0x0B */
> +#define ESR_ELx_EC_LS64B	UL(0x0A)

This EC code has been generalised recently. In the latest ARM ARM (ARM
DDI 0487 L.a), which can be found at:

  https://developer.arm.com/documentation/ddi0487/la/?lang=en

... the table on page D24-7333 refers to it as:

| Trapped execution of any instruction not covered by other EC values.

... and the corresponding ISS description is named:

| ISS encoding for an exception from any other instruction

... so maybe it makes sense to call it 'ESR_ELx_EC_OTHER_INSN',
'ESR_ELx_EC_INSN_MISC', or something of that rough shape?

With that, the PSB CSYNC oddity in patch 15 makes a bit more sense,
though the L.a release of the ARM ARM is still missing the description
of that.

Mark.

> +/* Unallocated EC: 0x0B */
>  #define ESR_ELx_EC_CP14_64	UL(0x0C)
>  #define ESR_ELx_EC_BTI		UL(0x0D)
>  #define ESR_ELx_EC_ILL		UL(0x0E)
> @@ -174,6 +175,11 @@
>  #define ESR_ELx_WFx_ISS_WFE	(UL(1) << 0)
>  #define ESR_ELx_xVC_IMM_MASK	((UL(1) << 16) - 1)
>  
> +/* ISS definitions for LD64B/ST64B instructions */
> +#define ESR_ELx_ISS_ST64BV	(0)
> +#define ESR_ELx_ISS_ST64BV0	(1)
> +#define ESR_ELx_ISS_LDST64B	(2)
> +
>  #define DISR_EL1_IDS		(UL(1) << 24)
>  /*
>   * DISR_EL1 and ESR_ELx share the bottom 13 bits, but the RES0 bits may mean
> -- 
> 2.39.2
>