diff options
Diffstat (limited to 'arch/arm64/include/uapi/asm/sigcontext.h')
-rw-r--r-- | arch/arm64/include/uapi/asm/sigcontext.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/arch/arm64/include/uapi/asm/sigcontext.h b/arch/arm64/include/uapi/asm/sigcontext.h index 5f3c0cec5af9..8b0ebce92427 100644 --- a/arch/arm64/include/uapi/asm/sigcontext.h +++ b/arch/arm64/include/uapi/asm/sigcontext.h @@ -77,6 +77,15 @@ struct fpsimd_context { __uint128_t vregs[32]; }; +/* + * Note: similarly to all other integer fields, each V-register is stored in an + * endianness-dependent format, with the byte at offset i from the start of the + * in-memory representation of the register value containing + * + * bits [(7 + 8 * i) : (8 * i)] of the register on little-endian hosts; or + * bits [(127 - 8 * i) : (120 - 8 * i)] on big-endian hosts. + */ + /* ESR_EL1 context */ #define ESR_MAGIC 0x45535201 @@ -137,7 +146,7 @@ struct sve_context { * vector length beyond its initial architectural limit of 2048 bits * (16 quadwords). * - * See linux/Documentation/arm64/sve.txt for a description of the VL/VQ + * See linux/Documentation/arm64/sve.rst for a description of the VL/VQ * terminology. */ #define SVE_VQ_BYTES __SVE_VQ_BYTES /* bytes per quadword */ @@ -204,6 +213,11 @@ struct sve_context { * FFR uint16_t[vq] first-fault status register * * Additional data might be appended in the future. + * + * Unlike vregs[] in fpsimd_context, each SVE scalable register (Z-, P- or FFR) + * is encoded in memory in an endianness-invariant format, with the byte at + * offset i from the start of the in-memory representation containing bits + * [(7 + 8 * i) : (8 * i)] of the register value. */ #define SVE_SIG_ZREG_SIZE(vq) __SVE_ZREG_SIZE(vq) |