arch: x86 -> x86_64 and build system changes

2017-10-10 23:24:07 +09:00
parent 51982de36b
commit 43ecf06e83
70 changed files with 50 additions and 56 deletions
--- a/arch/x86_64/kernel/vsyscall.c
+++ b/arch/x86_64/kernel/vsyscall.c
@ -0,0 +1,150 @@
+/**
+ * \file vsyscall.c
+ *  License details are found in the file LICENSE.
+ * \brief
+ *  implements x86's vsyscall
+ * \author Gou Nakamura  <go.nakamura.yw@hitachi-solutions.com> \par
+ * 	Copyright (C) 2014  Hitachi, Ltd.
+ * \author Gou Nakamura  <go.nakamura.yw@hitachi-solutions.com> \par
+ * 	Copyright (C) 2015  RIKEN AICS
+ */
+/*
+ * HISTORY:
+ */
+
+/*
+ * .vsyscall.* section's LMAs are different from their VMA.
+ * make sure that these are position-independent codes.
+ */
+
+#include <cls.h>
+#include <syscall.h>
+#include <ihk/atomic.h>
+#include <arch/cpu.h>
+
+extern int vsyscall_gettimeofday(struct timeval *tv, void *tz)
+	__attribute__ ((section (".vsyscall.gettimeofday")));
+
+struct tod_data_s tod_data
+		__attribute__ ((section(".vsyscall.gettimeofday.data"))) = {
+	.do_local =	0,
+	.version =	IHK_ATOMIC64_INIT(0),
+};
+
+static inline void cpu_pause_for_vsyscall(void)
+{
+	asm volatile ("pause" ::: "memory");
+	return;
+} /* cpu_pause_for_vsyscall() */
+
+static inline void calculate_time_from_tsc(struct timespec *ts)
+{
+	long ver;
+	unsigned long current_tsc;
+	__time_t sec_delta;
+	long ns_delta;
+
+	for (;;) {
+		while ((ver = ihk_atomic64_read(&tod_data.version)) & 1) {
+			/* settimeofday() is in progress */
+			cpu_pause_for_vsyscall();
+		}
+		rmb();
+		*ts = tod_data.origin;
+		rmb();
+		if (ver == ihk_atomic64_read(&tod_data.version)) {
+			break;
+		}
+
+		/* settimeofday() has intervened */
+		cpu_pause_for_vsyscall();
+	}
+
+	current_tsc = rdtsc();
+	sec_delta = current_tsc / tod_data.clocks_per_sec;
+	ns_delta = NS_PER_SEC * (current_tsc % tod_data.clocks_per_sec)
+		/ tod_data.clocks_per_sec;
+	/* calc. of ns_delta overflows if clocks_per_sec exceeds 18.44 GHz */
+
+	ts->tv_sec += sec_delta;
+	ts->tv_nsec += ns_delta;
+	if (ts->tv_nsec >= NS_PER_SEC) {
+		ts->tv_nsec -= NS_PER_SEC;
+		++ts->tv_sec;
+	}
+
+	return;
+} /* calculate_time_from_tsc() */
+
+int vsyscall_gettimeofday(struct timeval *tv, void *tz)
+{
+	int error;
+	struct timespec ats;
+
+	if (!tv && !tz) {
+		/* nothing to do */
+		return 0;
+	}
+
+	/* Do it locally if supported */
+	if (!tz && tod_data.do_local) {
+		calculate_time_from_tsc(&ats);
+
+		tv->tv_sec = ats.tv_sec;
+		tv->tv_usec = ats.tv_nsec / 1000;
+
+		return 0;
+	}
+
+	/* Otherwise syscall */
+	asm ("syscall" : "=a" (error)
+			: "a" (__NR_gettimeofday), "D" (tv), "S" (tz)
+			: "%rcx", "%r11", "memory");
+
+	if (error) {
+		*(volatile int *)0 = 0;	/* i.e. raise(SIGSEGV) */
+	}
+	return error;
+} /* vsyscall_gettimeofday() */
+
+extern long vsyscall_time(void *tp)
+	__attribute__ ((section (".vsyscall.time")));
+
+long vsyscall_time(void *tp)
+{
+	long t;
+
+	asm (		"syscall	;"
+			/*
+			 * This vsyscall_time() cannot fail, because glibc's
+			 * vsyscall_time() does not set the errno.
+			 *
+			 * Because a possible error is only a memory access error,
+			 * in order that this function generates SIGSEGV
+			 * rather than returns error when a memory access error occurs,
+			 * this function accesses memory in user mode.
+			 */
+			"test	%%rdx,%%rdx;"
+			"jz	1f;"
+			"mov	%%rax,(%%rdx);"
+			"1:"
+			: "=a" (t)
+			: "a" (__NR_time), "d" (tp), "D" (0)
+			: "%rcx", "%r11", "memory");
+
+	return t;
+}
+
+extern int vsyscall_getcpu(unsigned *cpup, unsigned *nodep, void *tcachep)
+	__attribute__ ((section (".vsyscall.getcpu")));
+
+int vsyscall_getcpu(unsigned *cpup, unsigned *nodep, void *tcachep)
+{
+	int error;
+
+	asm ("syscall" : "=a" (error)
+			: "a" (__NR_getcpu), "D" (cpup), "S" (nodep), "d" (tcachep)
+			: "%rcx", "%r11", "memory");
+
+	return error;
+}