return 0;
}
# endif /* __i386__ __x86_64__ */
-#elif defined(__alpha__)
-# ifdef HAVE_SYS_IO_H
-# include <sys/io.h>
-# else
-/* <asm/io.h> fails to compile, probably because of u8 etc */
-extern unsigned int inb(unsigned long port);
-extern void outb(unsigned char b, unsigned long port);
-extern int iopl(int level);
-# endif
-#else /* __alpha__ */
-# warning "disable cmos access - not i386, x86_64, or alpha"
+#else
+# warning "disable cmos access - not i386 or x86_64"
static void outb(int a __attribute__((__unused__)),
int b __attribute__((__unused__)))
{
#define IOPL_NOT_IMPLEMENTED -2
/*
- * The epoch.
- *
- * Unix uses 1900 as epoch for a struct tm, and 1970 for a time_t. But what
- * was written to CMOS?
- *
- * Digital DECstations use 1928 - this is on a mips or alpha Digital Unix
- * uses 1952, e.g. on AXPpxi33. Windows NT uses 1980. The ARC console
- * expects to boot Windows NT and uses 1980. (But a Ruffian uses 1900, just
- * like SRM.) It is reported that ALPHA_PRE_V1_2_SRM_CONSOLE uses 1958.
+ * POSIX uses 1900 as epoch for a struct tm, and 1970 for a time_t.
*/
#define TM_EPOCH 1900
-static int cmos_epoch = 1900;
-/*
- * Martin Ostermann writes:
- *
- * The problem with the Jensen is twofold: First, it has the clock at a
- * different address. Secondly, it has a distinction between "local" and
- * normal bus addresses. The local ones pertain to the hardware integrated
- * into the chipset, like serial/parallel ports and of course, the RTC.
- * Those need to be addressed differently. This is handled fine in the
- * kernel, and it's not a problem, since this usually gets totally optimized
- * by the compile. But the i/o routines of (g)libc lack this support so far.
- * The result of this is, that the old clock program worked only on the
- * Jensen when USE_DEV_PORT was defined, but not with the normal inb/outb
- * functions.
- */
-static int use_dev_port = 0; /* 1 for Jensen */
-static int dev_port_fd;
-static unsigned short clock_ctl_addr = 0x70; /* 0x170 for Jensen */
-static unsigned short clock_data_addr = 0x71; /* 0x171 for Jensen */
+static unsigned short clock_ctl_addr = 0x70;
+static unsigned short clock_data_addr = 0x71;
static int century_byte = 0; /* 0: don't access a century byte
* 50 (0x32): usual PC value
* 55 (0x37): PS/2
*/
-#ifdef __alpha__
-static int funkyTOY = 0; /* 1 for PC164/LX164/SX164 type alpha */
-#endif
-
-#ifdef __alpha
-
-static int is_in_cpuinfo(char *fmt, char *str)
-{
- FILE *cpuinfo;
- char field[256];
- char format[sizeof(field)];
- int found = 0;
-
- sprintf(format, "%s : %s", fmt, "%255s");
-
- cpuinfo = fopen(_PATH_PROC_CPUINFO, "r");
- if (cpuinfo) {
- do {
- if (fscanf(cpuinfo, format, field) == 1) {
- if (strncmp(field, str, strlen(str)) == 0)
- found = 1;
- break;
- }
- } while (fgets(field, 256, cpuinfo));
- fclose(cpuinfo);
- }
- return found;
-}
-
-/*
- * Set cmos_epoch, either from user options, or by asking the kernel, or by
- * looking at /proc/cpu_info
- */
-void set_cmos_epoch(const struct hwclock_control *ctl)
-{
- unsigned long epoch;
-
- /* Believe the user */
- if (ctl->epoch_option) {
- cmos_epoch = ctl->epoch_option;
- return;
- }
-
- if (ctl->ARCconsole)
- cmos_epoch = 1980;
-
- if (ctl->ARCconsole || ctl->SRM)
- return;
-
-#ifdef __linux__
- /*
- * If we can ask the kernel, we don't need guessing from
- * /proc/cpuinfo
- */
- if (get_epoch_rtc(ctl, &epoch, 1) == 0) {
- cmos_epoch = epoch;
- return;
- }
-#endif
-
- /*
- * The kernel source today says: read the year.
- *
- * If it is in 0-19 then the epoch is 2000.
- * If it is in 20-47 then the epoch is 1980.
- * If it is in 48-69 then the epoch is 1952.
- * If it is in 70-99 then the epoch is 1928.
- *
- * Otherwise the epoch is 1900.
- * TODO: Clearly, this must be changed before 2019.
- */
- /*
- * See whether we are dealing with SRM or MILO, as they have
- * different "epoch" ideas.
- */
- if (is_in_cpuinfo("system serial number", "MILO")) {
- if (ctl->debug)
- printf(_("booted from MILO\n"));
- /*
- * See whether we are dealing with a RUFFIAN aka Alpha PC-164
- * UX (or BX), as they have REALLY different TOY (TimeOfYear)
- * format: BCD, and not an ARC-style epoch. BCD is detected
- * dynamically, but we must NOT adjust like ARC.
- */
- if (is_in_cpuinfo("system type", "Ruffian")) {
- if (debug)
- printf(_("Ruffian BCD clock\n"));
- return;
- }
- }
-
- cmos_epoch = 1980;
-}
-
-void set_cmos_access(const struct hwclock_control *ctl)
-{
-
- /*
- * See whether we're dealing with a Jensen---it has a weird I/O
- * system. DEC was just learning how to build Alpha PCs.
- */
- if (ctl->Jensen || is_in_cpuinfo("system type", "Jensen")) {
- use_dev_port = 1;
- clock_ctl_addr = 0x170;
- clock_data_addr = 0x171;
- if (ctl->debug)
- printf(_("clockport adjusted to 0x%x\n"),
- clock_ctl_addr);
- }
-
- /*
- * See whether we are dealing with PC164/LX164/SX164, as they have a
- * TOY that must be accessed differently to work correctly.
- */
- /* Nautilus stuff reported by Neoklis Kyriazis */
- if (ctl->funky_toy ||
- is_in_cpuinfo("system variation", "PC164") ||
- is_in_cpuinfo("system variation", "LX164") ||
- is_in_cpuinfo("system variation", "SX164") ||
- is_in_cpuinfo("system type", "Nautilus")) {
- funkyTOY = 1;
- if (ctl->debug)
- printf(_("funky TOY!\n"));
- }
-}
-#endif /* __alpha */
-
-#ifdef __alpha__
-/*
- * The Alpha doesn't allow user-level code to disable interrupts (for good
- * reasons). Instead, we ensure atomic operation by performing the operation
- * and checking whether the high 32 bits of the cycle counter changed. If
- * they did, a context switch must have occurred and we redo the operation.
- * As long as the operation is reasonably short, it will complete
- * atomically, eventually.
- */
-static unsigned long
-atomic(const char *name,
- unsigned long (*op) (const struct hwclock_control *ctl, unsigned long),
- const struct hwclock_control *ctl,
- unsigned long arg)
-{
- unsigned long ts1, ts2, n, v;
-
- for (n = 0; n < 1000; ++n) {
- asm volatile ("rpcc %0":"r=" (ts1));
- v = (*op) (ctl, arg);
- asm volatile ("rpcc %0":"r=" (ts2));
-
- if ((ts1 ^ ts2) >> 32 == 0) {
- return v;
- }
- }
- errx(EXIT_FAILURE, _("atomic %s failed for 1000 iterations!"),
- name);
-}
-#else
-
/*
* Hmmh, this isn't very atomic. Maybe we should force an error instead?
*
return (*op) (ctl, arg);
}
-#endif
+/*
+ * We only want to read CMOS data, but unfortunately writing to bit 7
+ * disables (1) or enables (0) NMI; since this bit is read-only we have
+ * to guess the old status. Various docs suggest that one should disable
+ * NMI while reading/writing CMOS data, and enable it again afterwards.
+ * This would yield the sequence
+ *
+ * outb (reg | 0x80, 0x70);
+ * val = inb(0x71);
+ * outb (0x0d, 0x70); // 0x0d: random read-only location
+ *
+ * Other docs state that "any write to 0x70 should be followed by an
+ * action to 0x71 or the RTC will be left in an unknown state". Most
+ * docs say that it doesn't matter at all what one does.
+ *
+ * bit 0x80: disable NMI while reading - should we? Let us follow the
+ * kernel and not disable. Called only with 0 <= reg < 128
+ */
static inline unsigned long cmos_read(const struct hwclock_control *ctl,
unsigned long reg)
{
- if (use_dev_port) {
- unsigned char v = reg | 0x80;
- lseek(dev_port_fd, clock_ctl_addr, 0);
- if (write(dev_port_fd, &v, 1) == -1 && ctl->debug)
- warn(_("cmos_read(): write to control address %X failed"),
- clock_ctl_addr);
- lseek(dev_port_fd, clock_data_addr, 0);
- if (read(dev_port_fd, &v, 1) == -1 && ctl->debug)
- warn(_("cmos_read(): read from data address %X failed"),
- clock_data_addr);
- return v;
- } else {
- /*
- * We only want to read CMOS data, but unfortunately writing
- * to bit 7 disables (1) or enables (0) NMI; since this bit
- * is read-only we have to guess the old status. Various
- * docs suggest that one should disable NMI while
- * reading/writing CMOS data, and enable it again
- * afterwards. This would yield the sequence
- *
- * outb (reg | 0x80, 0x70);
- * val = inb(0x71);
- * outb (0x0d, 0x70); // 0x0d: random read-only location
- *
- * Other docs state that "any write to 0x70 should be
- * followed by an action to 0x71 or the RTC will be left in
- * an unknown state". Most docs say that it doesn't matter at
- * all what one does.
- */
- /*
- * bit 0x80: disable NMI while reading - should we? Let us
- * follow the kernel and not disable. Called only with 0 <=
- * reg < 128
- */
- outb(reg, clock_ctl_addr);
- return inb(clock_data_addr);
- }
+ outb(reg, clock_ctl_addr);
+ return inb(clock_data_addr);
}
static inline unsigned long cmos_write(const struct hwclock_control *ctl,
unsigned long reg, unsigned long val)
{
- if (use_dev_port) {
- unsigned char v = reg | 0x80;
- lseek(dev_port_fd, clock_ctl_addr, 0);
- if (write(dev_port_fd, &v, 1) == -1 && ctl->debug)
- warn(_("cmos_write(): write to control address %X failed"),
- clock_ctl_addr);
- v = (val & 0xff);
- lseek(dev_port_fd, clock_data_addr, 0);
- if (write(dev_port_fd, &v, 1) == -1 && ctl->debug)
- warn(_("cmos_write(): write to data address %X failed"),
- clock_data_addr);
- } else {
- outb(reg, clock_ctl_addr);
- outb(val, clock_data_addr);
- }
+ outb(reg, clock_ctl_addr);
+ outb(val, clock_data_addr);
return 0;
}
save_freq_select = cmos_read(ctl, 10); /* stop and reset prescaler */
cmos_write(ctl, 10, (save_freq_select | 0x70));
- tm.tm_year += TM_EPOCH;
- century = tm.tm_year / 100;
- tm.tm_year -= cmos_epoch;
+ century = (tm.tm_year + TM_EPOCH) / 100;
tm.tm_year %= 100;
tm.tm_mon += 1;
tm.tm_wday += 1;
static inline int cmos_clock_busy(const struct hwclock_control *ctl)
{
return
-#ifdef __alpha__
- /* poll bit 4 (UF) of Control Register C */
- funkyTOY ? (hclock_read(ctl, 12) & 0x10) :
-#endif
/* poll bit 7 (UIP) of Control Register A */
(hclock_read(ctl, 10) & 0x80);
}
*/
tm->tm_wday -= 1;
tm->tm_mon -= 1;
- tm->tm_year += (cmos_epoch - TM_EPOCH);
if (tm->tm_year < 69)
tm->tm_year += 100;
if (pmbit) {
return 0;
}
-#if defined(__i386__) || defined(__alpha__) || defined(__x86_64__)
+#if defined(__i386__) || defined(__x86_64__)
# if defined(HAVE_IOPL)
static int i386_iopl(const int level)
{
{
int rc;
- if (use_dev_port) {
- if ((dev_port_fd = open(_PATH_DEV_PORT, O_RDWR)) < 0) {
- warn(_("cannot open %s"), _PATH_DEV_PORT);
- rc = 1;
- } else
- rc = 0;
- } else {
- rc = i386_iopl(3);
- if (rc == IOPL_NOT_IMPLEMENTED) {
- warnx(_("I failed to get permission because I didn't try."));
- } else if (rc != 0) {
- rc = errno;
- warn(_("unable to get I/O port access: "
- "the iopl(3) call failed"));
- if (rc == EPERM && geteuid())
- warnx(_("Probably you need root privileges.\n"));
- }
+ rc = i386_iopl(3);
+ if (rc == IOPL_NOT_IMPLEMENTED) {
+ warnx(_("I failed to get permission because I didn't try."));
+ } else if (rc != 0) {
+ rc = errno;
+ warn(_("unable to get I/O port access: "
+ "the iopl(3) call failed"));
+ if (rc == EPERM && geteuid())
+ warnx(_("Probably you need root privileges.\n"));
}
return rc ? 1 : 0;
}
struct clock_ops *probe_for_cmos_clock(void)
{
static const int have_cmos =
-#if defined(__i386__) || defined(__alpha__) || defined(__x86_64__)
+#if defined(__i386__) || defined(__x86_64__)
TRUE;
#else
FALSE;
.B \-\-getepoch
.TQ
.B \-\-setepoch
-These functions are for Alpha machines only.
+These functions are for Alpha machines only, and are only available
+through the Linux kernel RTC driver.
.sp
-Read and set the kernel's Hardware Clock epoch value.
+They are used to read and set the kernel's Hardware Clock epoch value.
Epoch is the number of years into AD to which a zero year value in the
-Hardware Clock refers. For example, if you are using the convention
-that the year counter in your Hardware Clock contains the number of
-full years since 1952, then the kernel's Hardware Clock epoch value
-must be 1952.
+Hardware Clock refers. For example, if the machine's BIOS sets the year
+counter in the Hardware Clock to contain the number of full years since
+1952, then the kernel's Hardware Clock epoch value must be 1952.
.sp
The \fB\%\-\-setepoch\fR function requires using the
.B \%\-\-epoch
-option to specify the year.
-.sp
+option to specify the year. For example:
+.RS
+.IP "" 4
+.B hwclock\ \-\-setepoch\ \-\-epoch=1952
+.PP
+The RTC driver attempts to guess the correct epoch value, so setting it
+may not be required.
+.PP
This epoch value is used whenever
.B \%hwclock
-reads or sets the Hardware Clock.
+reads or sets the Hardware Clock on an Alpha machine. For ISA machines
+the kernel uses the fixed Hardware Clock epoch of 1900.
+.RE
.
.TP
.B \-\-predict
.
.TP
.B \-\-directisa
-This option is meaningful for: ISA compatible machines including x86, and
-x86_64; and Alpha (which has a similar Hardware Clock interface). For other
-machines, it has no effect. This option tells
+This option is meaningful for ISA compatible machines in the x86 and
+x86_64 family. For other machines, it has no effect. This option tells
.B \%hwclock
to use explicit I/O instructions to access the Hardware Clock.
Without this option,
.B \%hwclock
-will use the rtc device, which it assumes to be driven by the RTC device
-driver. As of v2.26 it will no longer automatically use directisa when
-the rtc driver is unavailable; this was causing an unsafe condition that
-could allow two processes to access the Hardware Clock at the same time.
-Direct hardware access from userspace should only be used for testing,
-troubleshooting, and as a last resort when all other methods fail. See
-the
+will use the rtc device file, which it assumes to be driven by the Linux
+RTC device driver. As of v2.26 it will no longer automatically use
+directisa when the rtc driver is unavailable; this was causing an unsafe
+condition that could allow two processes to access the Hardware Clock at
+the same time. Direct hardware access from userspace should only be
+used for testing, troubleshooting, and as a last resort when all other
+methods fail. See the
.BR \-\-rtc " option."
.
.TP
+.BI \-\-epoch= year
+This option is required when using the
+.BR \%\-\-setepoch \ function.
+.
+.TP
.BR \-f , \ \-\-rtc=\fIfilename\fR
.RB "Override " \%hwclock 's
default rtc device file name. Otherwise it will
.BR "The Adjust Function" .
.RE
.
-.SH OPTIONS FOR ALPHA MACHINES ONLY
-.
-.TP
-.B \-\-arc
-This option is equivalent to
-.B \%\-\-epoch=1980
-and is used to specify the most common epoch on Alphas
-with an ARC console (although Ruffians have an epoch of 1900).
-.
-.TP
-.BI \-\-epoch= year
-Specifies the year which is the beginning of the Hardware Clock's epoch,
-that is the number of years into AD to which a zero value in the
-Hardware Clock's year counter refers. It is used together with the
-.B \%\-\-setepoch
-option to set the kernel's idea of the epoch of the Hardware Clock.
-.sp
-For example, on a Digital Unix machine:
-.RS
-.IP "" 4
-.B hwclock\ \-\-setepoch\ \-\-epoch=1952
-.RE
-.
-.TP
-.B \-\-funky\-toy
-.TQ
-.B \-\-jensen
-These two options specify what kind of Alpha machine you have. They
-are invalid if you do not have an Alpha and are usually unnecessary
-if you do;
-.B \%hwclock
-should be able to determine what it is running on when
-.I \%/proc
-is mounted.
-.sp
-.RB "The " \%\-\-jensen
-option is used for Jensen models;
-.B \%\-\-funky\-toy
-means that the machine requires the UF bit instead of the UIP bit in
-the Hardware Clock to detect a time transition. The "toy" in the option
-name refers to the Time Of Year facility of the machine.
-.
-.TP
-.B \-\-srm
-This option is equivalent to
-.B \%\-\-epoch=1900
-and is used to specify the most common epoch on Alphas
-with an SRM console.
-.
.SH NOTES
.
.SS Clocks in a Linux System
direct I/O and disable interrupts.
.B \%hwclock
provides it for testing, troubleshooting, and because it may be the
-only method available on ISA compatible and Alpha systems which do not
-have a working rtc device driver.
-.PP
-In the case of a Jensen Alpha, there is no way for
-.B \%hwclock
-to execute those I/O instructions, and so it uses instead the
-.I \%/dev/port
-device special file, which provides almost as low-level an interface to
-the I/O subsystem.
+only method available on ISA systems which do not have a working rtc
+device driver.
.PP
On an m68k system,
.B \%hwclock
projects / thirdparty / util-linux.git / commitdiff
