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-rw-r--r--target/alpha/clk_helper.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/target/alpha/clk_helper.c b/target/alpha/clk_helper.c
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+++ b/target/alpha/clk_helper.c
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+/*
+ * QEMU Alpha clock helpers.
+ *
+ * Copyright (c) 2007 Jocelyn Mayer
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/timer.h"
+#include "exec/helper-proto.h"
+#include "cpu.h"
+
+uint64_t helper_load_pcc(CPUAlphaState *env)
+{
+#ifndef CONFIG_USER_ONLY
+ /*
+ * In system mode we have access to a decent high-resolution clock.
+ * In order to make OS-level time accounting work with the RPCC,
+ * present it with a well-timed clock fixed at 250MHz.
+ */
+ return (((uint64_t)env->pcc_ofs << 32)
+ | (uint32_t)(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) >> 2));
+#else
+ /*
+ * In user-mode, QEMU_CLOCK_VIRTUAL doesn't exist. Just pass through
+ * the host cpu clock ticks. Also, don't bother taking PCC_OFS into
+ * account.
+ */
+ return (uint32_t)cpu_get_host_ticks();
+#endif
+}