@@ -268,6 +268,62 @@ struct user_pac_generic_keys {
__uint128_t apgakey;
};
+/* ZA state (NT_ARM_ZA) */
+
+struct user_za_header {
+ __u32 size; /* total meaningful regset content in bytes */
+ __u32 max_size; /* maxmium possible size for this thread */
+ __u16 vl; /* current vector length */
+ __u16 max_vl; /* maximum possible vector length */
+ __u16 flags;
+ __u16 __reserved;
+};
+
+/*
+ * Common ZA_PT_* flags:
+ * These must be kept in sync with prctl interface in <linux/prctl.h>
+ */
+#define ZA_PT_VL_INHERIT ((1 << 17) /* PR_SME_VL_INHERIT */ >> 16)
+#define ZA_PT_VL_ONEXEC ((1 << 18) /* PR_SME_SET_VL_ONEXEC */ >> 16)
+
+
+/*
+ * The remainder of the ZA state follows struct user_za_header. The
+ * total size of the ZA state (including header) depends on the
+ * metadata in the header: ZA_PT_SIZE(vq, flags) gives the total size
+ * of the state in bytes, including the header.
+ *
+ * Refer to <asm/sigcontext.h> for details of how to pass the correct
+ * "vq" argument to these macros.
+ */
+
+/* Offset from the start of struct user_za_header to the register data */
+#define ZA_PT_ZA_OFFSET \
+ ((sizeof(struct user_za_header) + (__SVE_VQ_BYTES - 1)) \
+ / __SVE_VQ_BYTES * __SVE_VQ_BYTES)
+
+/*
+ * The payload starts at offset ZA_PT_ZA_OFFSET, and is of size
+ * ZA_PT_ZA_SIZE(vq, flags).
+ *
+ * The ZA array is stored as a sequence of horizontal vectors ZAV of SVL/8
+ * bytes each, starting from vector 0.
+ *
+ * Additional data might be appended in the future.
+ *
+ * The ZA matrix is represented in memory in an endianness-invariant layout
+ * which differs from the layout used for the FPSIMD V-registers on big-endian
+ * systems: see sigcontext.h for more explanation.
+ */
+
+#define ZA_PT_ZAV_OFFSET(vq, n) \
+ (ZA_PT_ZA_OFFSET + ((vq * __SVE_VQ_BYTES) * n))
+
+#define ZA_PT_ZA_SIZE(vq) ((vq * __SVE_VQ_BYTES) * (vq * __SVE_VQ_BYTES))
+
+#define ZA_PT_SIZE(vq) \
+ (ZA_PT_ZA_OFFSET + ZA_PT_ZA_SIZE(vq))
+
#endif /* __ASSEMBLY__ */
#endif /* _UAPI__ASM_PTRACE_H */
@@ -996,6 +996,141 @@ static int ssve_set(struct task_struct *target,
ARM64_VEC_SME);
}
+static int za_get(struct task_struct *target,
+ const struct user_regset *regset,
+ struct membuf to)
+{
+ struct user_za_header header;
+ unsigned int vq;
+ unsigned long start, end;
+
+ if (!system_supports_sme())
+ return -EINVAL;
+
+ /* Header */
+ memset(&header, 0, sizeof(header));
+
+ if (test_tsk_thread_flag(target, TIF_SME_VL_INHERIT))
+ header.flags |= ZA_PT_VL_INHERIT;
+
+ header.vl = task_get_sme_vl(target);
+ vq = sve_vq_from_vl(header.vl);
+ header.max_vl = sme_max_vl();
+ header.max_size = ZA_PT_SIZE(vq);
+
+ /* If ZA is not active there is only the header */
+ if (thread_za_enabled(&target->thread))
+ header.size = ZA_PT_SIZE(vq);
+ else
+ header.size = ZA_PT_ZA_OFFSET;
+
+ membuf_write(&to, &header, sizeof(header));
+
+ BUILD_BUG_ON(ZA_PT_ZA_OFFSET != sizeof(header));
+ end = ZA_PT_ZA_OFFSET;
+;
+ if (target == current)
+ fpsimd_preserve_current_state();
+
+ /* Any register data to include? */
+ if (thread_za_enabled(&target->thread)) {
+ start = end;
+ end = ZA_PT_SIZE(vq);
+ membuf_write(&to, target->thread.za_state, end - start);
+ }
+
+ /* Zero any trailing padding */
+ start = end;
+ end = ALIGN(header.size, SVE_VQ_BYTES);
+ return membuf_zero(&to, end - start);
+}
+
+static int za_set(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ int ret;
+ struct user_za_header header;
+ unsigned int vq;
+ unsigned long start, end;
+
+ if (!system_supports_sme())
+ return -EINVAL;
+
+ /* Header */
+ if (count < sizeof(header))
+ return -EINVAL;
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &header,
+ 0, sizeof(header));
+ if (ret)
+ goto out;
+
+ /*
+ * All current ZA_PT_* flags are consumed by
+ * vec_set_vector_length(), which will also validate them for
+ * us:
+ */
+ ret = vec_set_vector_length(target, ARM64_VEC_SME, header.vl,
+ ((unsigned long)header.flags) << 16);
+ if (ret)
+ goto out;
+
+ /* Actual VL set may be less than the user asked for: */
+ vq = sve_vq_from_vl(task_get_sme_vl(target));
+
+ /* Ensure there is some SVE storage for streaming mode */
+ if (!target->thread.sve_state) {
+ sve_alloc(target);
+ if (!target->thread.sve_state) {
+ clear_thread_flag(TIF_SME);
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+
+ /* Allocate/reinit ZA storage */
+ sme_alloc(target);
+ if (!target->thread.za_state) {
+ ret = -ENOMEM;
+ clear_tsk_thread_flag(target, TIF_SME);
+ goto out;
+ }
+
+ /* If there is no data then disable ZA */
+ if (!count) {
+ target->thread.svcr &= ~SYS_SVCR_EL0_ZA_MASK;
+ goto out;
+ }
+
+ /*
+ * If setting a different VL from the requested VL and there is
+ * register data, the data layout will be wrong: don't even
+ * try to set the registers in this case.
+ */
+ if (vq != sve_vq_from_vl(header.vl)) {
+ ret = -EIO;
+ goto out;
+ }
+
+ BUILD_BUG_ON(ZA_PT_ZA_OFFSET != sizeof(header));
+ start = ZA_PT_ZA_OFFSET;
+ end = ZA_PT_SIZE(vq);
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ target->thread.za_state,
+ start, end);
+ if (ret)
+ goto out;
+
+ /* Mark ZA as active and let userspace use it */
+ set_tsk_thread_flag(target, TIF_SME);
+ target->thread.svcr |= SYS_SVCR_EL0_ZA_MASK;
+
+out:
+ fpsimd_flush_task_state(target);
+ return ret;
+}
+
#endif /* CONFIG_ARM64_SME */
#ifdef CONFIG_ARM64_PTR_AUTH
@@ -1217,6 +1352,7 @@ enum aarch64_regset {
#endif
#ifdef CONFIG_ARM64_SVE
REGSET_SSVE,
+ REGSET_ZA,
#endif
#ifdef CONFIG_ARM64_PTR_AUTH
REGSET_PAC_MASK,
@@ -1308,6 +1444,14 @@ static const struct user_regset aarch64_regsets[] = {
.regset_get = ssve_get,
.set = ssve_set,
},
+ [REGSET_ZA] = { /* SME ZA */
+ .core_note_type = NT_ARM_ZA,
+ .n = DIV_ROUND_UP(ZA_PT_ZA_SIZE(SVE_VQ_MAX), SVE_VQ_BYTES),
+ .size = SVE_VQ_BYTES,
+ .align = SVE_VQ_BYTES,
+ .regset_get = za_get,
+ .set = za_set,
+ },
#endif
#ifdef CONFIG_ARM64_PTR_AUTH
[REGSET_PAC_MASK] = {
@@ -428,6 +428,7 @@ typedef struct elf64_shdr {
#define NT_ARM_TAGGED_ADDR_CTRL 0x409 /* arm64 tagged address control (prctl()) */
#define NT_ARM_PAC_ENABLED_KEYS 0x40a /* arm64 ptr auth enabled keys (prctl()) */
#define NT_ARM_SSVE 0x40b /* ARM Streaming SVE registers */
+#define NT_ARM_ZA 0x40c /* ARM SME ZA registers */
#define NT_ARC_V2 0x600 /* ARCv2 accumulator/extra registers */
#define NT_VMCOREDD 0x700 /* Vmcore Device Dump Note */
#define NT_MIPS_DSP 0x800 /* MIPS DSP ASE registers */