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authorLinus Torvalds <torvalds@linux-foundation.org>2015-11-15 20:10:53 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2015-11-15 20:10:53 +0300
commitb84da9fa47cf6e8dfd71d673a2f744ec1cac452c (patch)
tree800a1cb1e939eb84f7e7018be64e94be5c972ca0 /arch/mips/vdso/gettimeofday.c
parent12b76f3bf336388916ddf8047156f9e9993ff4e9 (diff)
parentda34232641a91ca785a787c23c158488e459b938 (diff)
downloadlinux-b84da9fa47cf6e8dfd71d673a2f744ec1cac452c.tar.xz
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS updates from Ralf Baechle: "These are the highlists of the main MIPS pull request for 4.4: - Add latencytop support - Support appended DTBs - VDSO support and initially use it for gettimeofday. - Drop the .MIPS.abiflags and ELF NOTE sections from vmlinux - Support for the 5KE, an internal test core. - Switch all MIPS platfroms to libata drivers. - Improved support, cleanups for ralink and Lantiq platforms. - Support for the new xilfpga platform. - A number of DTB improvments for BMIPS. - Improved support for CM and CPS. - Minor JZ4740 and BCM47xx enhancements" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (120 commits) MIPS: idle: add case for CPU_5KE MIPS: Octeon: Support APPENDED_DTB MIPS: vmlinux: create a section for appended DTB MIPS: Clean up compat_siginfo_t MIPS: Fix PAGE_MASK definition MIPS: BMIPS: Enable GZIP ramdisk and timed printks MIPS: Add xilfpga defconfig MIPS: xilfpga: Add mipsfpga platform code MIPS: xilfpga: Add xilfpga device tree files. dt-bindings: MIPS: Document xilfpga bindings and boot style MIPS: Make MIPS_CMDLINE_DTB default MIPS: Make the kernel arguments from dtb available MIPS: Use USE_OF as the guard for appended dtb MIPS: BCM63XX: Use pr_* instead of printk MIPS: Loongson: Cleanup CONFIG_LOONGSON_SUSPEND. MIPS: lantiq: Disable xbar fpi burst mode MIPS: lantiq: Force the crossbar to big endian MIPS: lantiq: Initialize the USB core on boot MIPS: lantiq: Return correct value for fpi clock on ar9 MIPS: ralink: Add missing clock on rt305x ...
Diffstat (limited to 'arch/mips/vdso/gettimeofday.c')
-rw-r--r--arch/mips/vdso/gettimeofday.c232
1 files changed, 232 insertions, 0 deletions
diff --git a/arch/mips/vdso/gettimeofday.c b/arch/mips/vdso/gettimeofday.c
new file mode 100644
index 000000000000..ce89c9e294f9
--- /dev/null
+++ b/arch/mips/vdso/gettimeofday.c
@@ -0,0 +1,232 @@
+/*
+ * Copyright (C) 2015 Imagination Technologies
+ * Author: Alex Smith <alex.smith@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include "vdso.h"
+
+#include <linux/compiler.h>
+#include <linux/irqchip/mips-gic.h>
+#include <linux/time.h>
+
+#include <asm/clocksource.h>
+#include <asm/io.h>
+#include <asm/mips-cm.h>
+#include <asm/unistd.h>
+#include <asm/vdso.h>
+
+static __always_inline int do_realtime_coarse(struct timespec *ts,
+ const union mips_vdso_data *data)
+{
+ u32 start_seq;
+
+ do {
+ start_seq = vdso_data_read_begin(data);
+
+ ts->tv_sec = data->xtime_sec;
+ ts->tv_nsec = data->xtime_nsec >> data->cs_shift;
+ } while (vdso_data_read_retry(data, start_seq));
+
+ return 0;
+}
+
+static __always_inline int do_monotonic_coarse(struct timespec *ts,
+ const union mips_vdso_data *data)
+{
+ u32 start_seq;
+ u32 to_mono_sec;
+ u32 to_mono_nsec;
+
+ do {
+ start_seq = vdso_data_read_begin(data);
+
+ ts->tv_sec = data->xtime_sec;
+ ts->tv_nsec = data->xtime_nsec >> data->cs_shift;
+
+ to_mono_sec = data->wall_to_mono_sec;
+ to_mono_nsec = data->wall_to_mono_nsec;
+ } while (vdso_data_read_retry(data, start_seq));
+
+ ts->tv_sec += to_mono_sec;
+ timespec_add_ns(ts, to_mono_nsec);
+
+ return 0;
+}
+
+#ifdef CONFIG_CSRC_R4K
+
+static __always_inline u64 read_r4k_count(void)
+{
+ unsigned int count;
+
+ __asm__ __volatile__(
+ " .set push\n"
+ " .set mips32r2\n"
+ " rdhwr %0, $2\n"
+ " .set pop\n"
+ : "=r" (count));
+
+ return count;
+}
+
+#endif
+
+#ifdef CONFIG_CLKSRC_MIPS_GIC
+
+static __always_inline u64 read_gic_count(const union mips_vdso_data *data)
+{
+ void __iomem *gic = get_gic(data);
+ u32 hi, hi2, lo;
+
+ do {
+ hi = __raw_readl(gic + GIC_UMV_SH_COUNTER_63_32_OFS);
+ lo = __raw_readl(gic + GIC_UMV_SH_COUNTER_31_00_OFS);
+ hi2 = __raw_readl(gic + GIC_UMV_SH_COUNTER_63_32_OFS);
+ } while (hi2 != hi);
+
+ return (((u64)hi) << 32) + lo;
+}
+
+#endif
+
+static __always_inline u64 get_ns(const union mips_vdso_data *data)
+{
+ u64 cycle_now, delta, nsec;
+
+ switch (data->clock_mode) {
+#ifdef CONFIG_CSRC_R4K
+ case VDSO_CLOCK_R4K:
+ cycle_now = read_r4k_count();
+ break;
+#endif
+#ifdef CONFIG_CLKSRC_MIPS_GIC
+ case VDSO_CLOCK_GIC:
+ cycle_now = read_gic_count(data);
+ break;
+#endif
+ default:
+ return 0;
+ }
+
+ delta = (cycle_now - data->cs_cycle_last) & data->cs_mask;
+
+ nsec = (delta * data->cs_mult) + data->xtime_nsec;
+ nsec >>= data->cs_shift;
+
+ return nsec;
+}
+
+static __always_inline int do_realtime(struct timespec *ts,
+ const union mips_vdso_data *data)
+{
+ u32 start_seq;
+ u64 ns;
+
+ do {
+ start_seq = vdso_data_read_begin(data);
+
+ if (data->clock_mode == VDSO_CLOCK_NONE)
+ return -ENOSYS;
+
+ ts->tv_sec = data->xtime_sec;
+ ns = get_ns(data);
+ } while (vdso_data_read_retry(data, start_seq));
+
+ ts->tv_nsec = 0;
+ timespec_add_ns(ts, ns);
+
+ return 0;
+}
+
+static __always_inline int do_monotonic(struct timespec *ts,
+ const union mips_vdso_data *data)
+{
+ u32 start_seq;
+ u64 ns;
+ u32 to_mono_sec;
+ u32 to_mono_nsec;
+
+ do {
+ start_seq = vdso_data_read_begin(data);
+
+ if (data->clock_mode == VDSO_CLOCK_NONE)
+ return -ENOSYS;
+
+ ts->tv_sec = data->xtime_sec;
+ ns = get_ns(data);
+
+ to_mono_sec = data->wall_to_mono_sec;
+ to_mono_nsec = data->wall_to_mono_nsec;
+ } while (vdso_data_read_retry(data, start_seq));
+
+ ts->tv_sec += to_mono_sec;
+ ts->tv_nsec = 0;
+ timespec_add_ns(ts, ns + to_mono_nsec);
+
+ return 0;
+}
+
+#ifdef CONFIG_MIPS_CLOCK_VSYSCALL
+
+/*
+ * This is behind the ifdef so that we don't provide the symbol when there's no
+ * possibility of there being a usable clocksource, because there's nothing we
+ * can do without it. When libc fails the symbol lookup it should fall back on
+ * the standard syscall path.
+ */
+int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz)
+{
+ const union mips_vdso_data *data = get_vdso_data();
+ struct timespec ts;
+ int ret;
+
+ ret = do_realtime(&ts, data);
+ if (ret)
+ return ret;
+
+ if (tv) {
+ tv->tv_sec = ts.tv_sec;
+ tv->tv_usec = ts.tv_nsec / 1000;
+ }
+
+ if (tz) {
+ tz->tz_minuteswest = data->tz_minuteswest;
+ tz->tz_dsttime = data->tz_dsttime;
+ }
+
+ return 0;
+}
+
+#endif /* CONFIG_CLKSRC_MIPS_GIC */
+
+int __vdso_clock_gettime(clockid_t clkid, struct timespec *ts)
+{
+ const union mips_vdso_data *data = get_vdso_data();
+ int ret;
+
+ switch (clkid) {
+ case CLOCK_REALTIME_COARSE:
+ ret = do_realtime_coarse(ts, data);
+ break;
+ case CLOCK_MONOTONIC_COARSE:
+ ret = do_monotonic_coarse(ts, data);
+ break;
+ case CLOCK_REALTIME:
+ ret = do_realtime(ts, data);
+ break;
+ case CLOCK_MONOTONIC:
+ ret = do_monotonic(ts, data);
+ break;
+ default:
+ ret = -ENOSYS;
+ break;
+ }
+
+ /* If we return -ENOSYS libc should fall back to a syscall. */
+ return ret;
+}