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-rw-r--r--arch/arm64/include/uapi/asm/sigcontext.h41
1 files changed, 41 insertions, 0 deletions
diff --git a/arch/arm64/include/uapi/asm/sigcontext.h b/arch/arm64/include/uapi/asm/sigcontext.h
index 57e9f8c3ee9e..4aaf31e3bf16 100644
--- a/arch/arm64/include/uapi/asm/sigcontext.h
+++ b/arch/arm64/include/uapi/asm/sigcontext.h
@@ -140,6 +140,14 @@ struct sve_context {
#define SVE_SIG_FLAG_SM 0x1 /* Context describes streaming mode */
+#define ZA_MAGIC 0x54366345
+
+struct za_context {
+ struct _aarch64_ctx head;
+ __u16 vl;
+ __u16 __reserved[3];
+};
+
#endif /* !__ASSEMBLY__ */
#include <asm/sve_context.h>
@@ -259,4 +267,37 @@ struct sve_context {
#define SVE_SIG_CONTEXT_SIZE(vq) \
(SVE_SIG_REGS_OFFSET + SVE_SIG_REGS_SIZE(vq))
+/*
+ * If the ZA register is enabled for the thread at signal delivery then,
+ * za_context.head.size >= ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(za_context.vl))
+ * and the register data may be accessed using the ZA_SIG_*() macros.
+ *
+ * If za_context.head.size < ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(za_context.vl))
+ * then ZA was not enabled and no register data was included in which case
+ * ZA register was not enabled for the thread and no register data
+ * the ZA_SIG_*() macros should not be used except for this check.
+ *
+ * The same convention applies when returning from a signal: a caller
+ * will need to remove or resize the za_context block if it wants to
+ * enable the ZA register when it was previously non-live or vice-versa.
+ * This may require the caller to allocate fresh memory and/or move other
+ * context blocks in the signal frame.
+ *
+ * Changing the vector length during signal return is not permitted:
+ * za_context.vl must equal the thread's current SME vector length when
+ * doing a sigreturn.
+ */
+
+#define ZA_SIG_REGS_OFFSET \
+ ((sizeof(struct za_context) + (__SVE_VQ_BYTES - 1)) \
+ / __SVE_VQ_BYTES * __SVE_VQ_BYTES)
+
+#define ZA_SIG_REGS_SIZE(vq) ((vq * __SVE_VQ_BYTES) * (vq * __SVE_VQ_BYTES))
+
+#define ZA_SIG_ZAV_OFFSET(vq, n) (ZA_SIG_REGS_OFFSET + \
+ (SVE_SIG_ZREG_SIZE(vq) * n))
+
+#define ZA_SIG_CONTEXT_SIZE(vq) \
+ (ZA_SIG_REGS_OFFSET + ZA_SIG_REGS_SIZE(vq))
+
#endif /* _UAPI__ASM_SIGCONTEXT_H */