1 files changed, 69 insertions, 0 deletions
diff --git a/arch/s390/kernel/perf_regs.c b/arch/s390/kernel/perf_regs.c
new file mode 100644
index 000000000..4352a504f
--- /dev/null
+++ b/arch/s390/kernel/perf_regs.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/perf_event.h>
+#include <linux/perf_regs.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/bug.h>
+#include <asm/ptrace.h>
+#include <asm/fpu/api.h>
+#include <asm/fpu/types.h>
+
+u64 perf_reg_value(struct pt_regs *regs, int idx)
+{
+	freg_t fp;
+
+	if (idx >= PERF_REG_S390_R0 && idx <= PERF_REG_S390_R15)
+		return regs->gprs[idx];
+
+	if (idx >= PERF_REG_S390_FP0 && idx <= PERF_REG_S390_FP15) {
+		if (!user_mode(regs))
+			return 0;
+
+		idx -= PERF_REG_S390_FP0;
+		fp = MACHINE_HAS_VX ? *(freg_t *)(current->thread.fpu.vxrs + idx)
+				    : current->thread.fpu.fprs[idx];
+		return fp.ui;
+	}
+
+	if (idx == PERF_REG_S390_MASK)
+		return regs->psw.mask;
+	if (idx == PERF_REG_S390_PC)
+		return regs->psw.addr;
+
+	WARN_ON_ONCE((u32)idx >= PERF_REG_S390_MAX);
+	return 0;
+}
+
+#define REG_RESERVED (~((1UL << PERF_REG_S390_MAX) - 1))
+
+int perf_reg_validate(u64 mask)
+{
+	if (!mask || mask & REG_RESERVED)
+		return -EINVAL;
+
+	return 0;
+}
+
+u64 perf_reg_abi(struct task_struct *task)
+{
+	if (test_tsk_thread_flag(task, TIF_31BIT))
+		return PERF_SAMPLE_REGS_ABI_32;
+
+	return PERF_SAMPLE_REGS_ABI_64;
+}
+
+void perf_get_regs_user(struct perf_regs *regs_user,
+			struct pt_regs *regs,
+			struct pt_regs *regs_user_copy)
+{
+	/*
+	 * Use the regs from the first interruption and let
+	 * perf_sample_regs_intr() handle interrupts (regs == get_irq_regs()).
+	 *
+	 * Also save FPU registers for user-space tasks only.
+	 */
+	regs_user->regs = task_pt_regs(current);
+	if (user_mode(regs_user->regs))
+		save_fpu_regs();
+	regs_user->abi = perf_reg_abi(current);
+}