From: Atsushi Nemoto Date: Wed, 2 Nov 2005 16:01:15 +0000 (+0900) Subject: Use rtc_lock to protect RTC operations X-Git-Tag: v2.6.15-rc1~446^2~6 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=53c2df2f4ebbc1d8231ca7cc13ac5381230888b1;p=linux-2.6 Use rtc_lock to protect RTC operations Many RTC routines were not protected against each other, so there are potential races, for example, ntp-update against /dev/rtc. This patch fixes them using rtc_lock. Signed-off-by: Atsushi Nemoto Signed-off-by: Ralf Baechle --- diff --git a/arch/mips/ddb5xxx/common/rtc_ds1386.c b/arch/mips/ddb5xxx/common/rtc_ds1386.c index f5b11508ff..995896ac0e 100644 --- a/arch/mips/ddb5xxx/common/rtc_ds1386.c +++ b/arch/mips/ddb5xxx/common/rtc_ds1386.c @@ -41,7 +41,9 @@ rtc_ds1386_get_time(void) u8 byte; u8 temp; unsigned int year, month, day, hour, minute, second; + unsigned long flags; + spin_lock_irqsave(&rtc_lock, flags); /* let us freeze external registers */ byte = READ_RTC(0xB); byte &= 0x3f; @@ -60,6 +62,7 @@ rtc_ds1386_get_time(void) /* enable time transfer */ byte |= 0x80; WRITE_RTC(0xB, byte); + spin_unlock_irqrestore(&rtc_lock, flags); /* calc hour */ if (temp & 0x40) { @@ -81,7 +84,9 @@ rtc_ds1386_set_time(unsigned long t) u8 byte; u8 temp; u8 year, month, day, hour, minute, second; + unsigned long flags; + spin_lock_irqsave(&rtc_lock, flags); /* let us freeze external registers */ byte = READ_RTC(0xB); byte &= 0x3f; @@ -133,6 +138,7 @@ rtc_ds1386_set_time(unsigned long t) if (second != READ_RTC(0x1)) { WRITE_RTC(0x1, second); } + spin_unlock_irqrestore(&rtc_lock, flags); return 0; } diff --git a/arch/mips/dec/time.c b/arch/mips/dec/time.c index dc7091caa7..1748223441 100644 --- a/arch/mips/dec/time.c +++ b/arch/mips/dec/time.c @@ -37,10 +37,25 @@ #include +/* + * Returns true if a clock update is in progress + */ +static inline unsigned char dec_rtc_is_updating(void) +{ + unsigned char uip; + unsigned long flags; + + spin_lock_irqsave(&rtc_lock, flags); + uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP); + spin_unlock_irqrestore(&rtc_lock, flags); + return uip; +} + static unsigned long dec_rtc_get_time(void) { unsigned int year, mon, day, hour, min, sec, real_year; int i; + unsigned long flags; /* The Linux interpretation of the DS1287 clock register contents: * When the Update-In-Progress (UIP) flag goes from 1 to 0, the @@ -49,11 +64,12 @@ static unsigned long dec_rtc_get_time(void) */ /* read RTC exactly on falling edge of update flag */ for (i = 0; i < 1000000; i++) /* may take up to 1 second... */ - if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP) + if (dec_rtc_is_updating()) break; for (i = 0; i < 1000000; i++) /* must try at least 2.228 ms */ - if (!(CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP)) + if (!dec_rtc_is_updating()) break; + spin_lock_irqsave(&rtc_lock, flags); /* Isn't this overkill? UIP above should guarantee consistency */ do { sec = CMOS_READ(RTC_SECONDS); @@ -77,6 +93,7 @@ static unsigned long dec_rtc_get_time(void) * of unused BBU RAM locations. */ real_year = CMOS_READ(RTC_DEC_YEAR); + spin_unlock_irqrestore(&rtc_lock, flags); year += real_year - 72 + 2000; return mktime(year, mon, day, hour, min, sec); @@ -95,6 +112,8 @@ static int dec_rtc_set_mmss(unsigned long nowtime) int real_seconds, real_minutes, cmos_minutes; unsigned char save_control, save_freq_select; + /* irq are locally disabled here */ + spin_lock(&rtc_lock); /* tell the clock it's being set */ save_control = CMOS_READ(RTC_CONTROL); CMOS_WRITE((save_control | RTC_SET), RTC_CONTROL); @@ -141,6 +160,7 @@ static int dec_rtc_set_mmss(unsigned long nowtime) */ CMOS_WRITE(save_control, RTC_CONTROL); CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); + spin_unlock(&rtc_lock); return retval; } diff --git a/arch/mips/jmr3927/common/rtc_ds1742.c b/arch/mips/jmr3927/common/rtc_ds1742.c index 1ae4318e13..8b407d7dc4 100644 --- a/arch/mips/jmr3927/common/rtc_ds1742.c +++ b/arch/mips/jmr3927/common/rtc_ds1742.c @@ -57,7 +57,9 @@ rtc_ds1742_get_time(void) { unsigned int year, month, day, hour, minute, second; unsigned int century; + unsigned long flags; + spin_lock_irqsave(&rtc_lock, flags); CMOS_WRITE(RTC_READ, RTC_CONTROL); second = BCD2BIN(CMOS_READ(RTC_SECONDS) & RTC_SECONDS_MASK); minute = BCD2BIN(CMOS_READ(RTC_MINUTES)); @@ -67,6 +69,7 @@ rtc_ds1742_get_time(void) year = BCD2BIN(CMOS_READ(RTC_YEAR)); century = BCD2BIN(CMOS_READ(RTC_CENTURY) & RTC_CENTURY_MASK); CMOS_WRITE(0, RTC_CONTROL); + spin_unlock_irqrestore(&rtc_lock, flags); year += century * 100; @@ -81,7 +84,9 @@ rtc_ds1742_set_time(unsigned long t) u8 year, month, day, hour, minute, second; u8 cmos_year, cmos_month, cmos_day, cmos_hour, cmos_minute, cmos_second; int cmos_century; + unsigned long flags; + spin_lock_irqsave(&rtc_lock, flags); CMOS_WRITE(RTC_READ, RTC_CONTROL); cmos_second = (u8)(CMOS_READ(RTC_SECONDS) & RTC_SECONDS_MASK); cmos_minute = (u8)CMOS_READ(RTC_MINUTES); @@ -139,6 +144,7 @@ rtc_ds1742_set_time(unsigned long t) /* RTC_CENTURY and RTC_CONTROL share same address... */ CMOS_WRITE(cmos_century, RTC_CONTROL); + spin_unlock_irqrestore(&rtc_lock, flags); return 0; } diff --git a/arch/mips/lasat/ds1603.c b/arch/mips/lasat/ds1603.c index 9d7812e03d..7dced67c55 100644 --- a/arch/mips/lasat/ds1603.c +++ b/arch/mips/lasat/ds1603.c @@ -8,6 +8,7 @@ #include #include #include +#include #include "ds1603.h" @@ -138,19 +139,27 @@ static void rtc_end_op(void) unsigned long ds1603_read(void) { unsigned long word; + unsigned long flags; + + spin_lock_irqsave(&rtc_lock, flags); rtc_init_op(); rtc_write_byte(READ_TIME_CMD); word = rtc_read_word(); rtc_end_op(); + spin_unlock_irqrestore(&rtc_lock, flags); return word; } int ds1603_set(unsigned long time) { + unsigned long flags; + + spin_lock_irqsave(&rtc_lock, flags); rtc_init_op(); rtc_write_byte(SET_TIME_CMD); rtc_write_word(time); rtc_end_op(); + spin_unlock_irqrestore(&rtc_lock, flags); return 0; } diff --git a/arch/mips/momentum/jaguar_atx/setup.c b/arch/mips/momentum/jaguar_atx/setup.c index 768bf44064..bab192ddc1 100644 --- a/arch/mips/momentum/jaguar_atx/setup.c +++ b/arch/mips/momentum/jaguar_atx/setup.c @@ -149,7 +149,9 @@ arch_initcall(per_cpu_mappings); unsigned long m48t37y_get_time(void) { unsigned int year, month, day, hour, min, sec; + unsigned long flags; + spin_lock_irqsave(&rtc_lock, flags); /* stop the update */ rtc_base[0x7ff8] = 0x40; @@ -166,6 +168,7 @@ unsigned long m48t37y_get_time(void) /* start the update */ rtc_base[0x7ff8] = 0x00; + spin_unlock_irqrestore(&rtc_lock, flags); return mktime(year, month, day, hour, min, sec); } @@ -173,11 +176,13 @@ unsigned long m48t37y_get_time(void) int m48t37y_set_time(unsigned long sec) { struct rtc_time tm; + unsigned long flags; /* convert to a more useful format -- note months count from 0 */ to_tm(sec, &tm); tm.tm_mon += 1; + spin_lock_irqsave(&rtc_lock, flags); /* enable writing */ rtc_base[0x7ff8] = 0x80; @@ -201,6 +206,7 @@ int m48t37y_set_time(unsigned long sec) /* disable writing */ rtc_base[0x7ff8] = 0x00; + spin_unlock_irqrestore(&rtc_lock, flags); return 0; } diff --git a/arch/mips/momentum/ocelot_3/setup.c b/arch/mips/momentum/ocelot_3/setup.c index a7803e08f9..c9b7ff8148 100644 --- a/arch/mips/momentum/ocelot_3/setup.c +++ b/arch/mips/momentum/ocelot_3/setup.c @@ -135,7 +135,9 @@ void setup_wired_tlb_entries(void) unsigned long m48t37y_get_time(void) { unsigned int year, month, day, hour, min, sec; + unsigned long flags; + spin_lock_irqsave(&rtc_lock, flags); /* stop the update */ rtc_base[0x7ff8] = 0x40; @@ -152,6 +154,7 @@ unsigned long m48t37y_get_time(void) /* start the update */ rtc_base[0x7ff8] = 0x00; + spin_unlock_irqrestore(&rtc_lock, flags); return mktime(year, month, day, hour, min, sec); } @@ -159,11 +162,13 @@ unsigned long m48t37y_get_time(void) int m48t37y_set_time(unsigned long sec) { struct rtc_time tm; + unsigned long flags; /* convert to a more useful format -- note months count from 0 */ to_tm(sec, &tm); tm.tm_mon += 1; + spin_lock_irqsave(&rtc_lock, flags); /* enable writing */ rtc_base[0x7ff8] = 0x80; @@ -187,6 +192,7 @@ int m48t37y_set_time(unsigned long sec) /* disable writing */ rtc_base[0x7ff8] = 0x00; + spin_unlock_irqrestore(&rtc_lock, flags); return 0; } diff --git a/arch/mips/momentum/ocelot_c/setup.c b/arch/mips/momentum/ocelot_c/setup.c index ce70fc96f1..2755c15474 100644 --- a/arch/mips/momentum/ocelot_c/setup.c +++ b/arch/mips/momentum/ocelot_c/setup.c @@ -140,7 +140,9 @@ unsigned long m48t37y_get_time(void) unsigned char* rtc_base = (unsigned char*)0xfc800000; #endif unsigned int year, month, day, hour, min, sec; + unsigned long flags; + spin_lock_irqsave(&rtc_lock, flags); /* stop the update */ rtc_base[0x7ff8] = 0x40; @@ -157,6 +159,7 @@ unsigned long m48t37y_get_time(void) /* start the update */ rtc_base[0x7ff8] = 0x00; + spin_unlock_irqrestore(&rtc_lock, flags); return mktime(year, month, day, hour, min, sec); } @@ -169,11 +172,13 @@ int m48t37y_set_time(unsigned long sec) unsigned char* rtc_base = (unsigned char*)0xfc800000; #endif struct rtc_time tm; + unsigned long flags; /* convert to a more useful format -- note months count from 0 */ to_tm(sec, &tm); tm.tm_mon += 1; + spin_lock_irqsave(&rtc_lock, flags); /* enable writing */ rtc_base[0x7ff8] = 0x80; @@ -197,6 +202,7 @@ int m48t37y_set_time(unsigned long sec) /* disable writing */ rtc_base[0x7ff8] = 0x00; + spin_unlock_irqrestore(&rtc_lock, flags); return 0; } diff --git a/arch/mips/pmc-sierra/yosemite/setup.c b/arch/mips/pmc-sierra/yosemite/setup.c index bdc2ab55be..059755b5ed 100644 --- a/arch/mips/pmc-sierra/yosemite/setup.c +++ b/arch/mips/pmc-sierra/yosemite/setup.c @@ -73,7 +73,9 @@ void __init bus_error_init(void) unsigned long m48t37y_get_time(void) { unsigned int year, month, day, hour, min, sec; + unsigned long flags; + spin_lock_irqsave(&rtc_lock, flags); /* Stop the update to the time */ m48t37_base->control = 0x40; @@ -88,6 +90,7 @@ unsigned long m48t37y_get_time(void) /* Start the update to the time again */ m48t37_base->control = 0x00; + spin_unlock_irqrestore(&rtc_lock, flags); return mktime(year, month, day, hour, min, sec); } @@ -95,11 +98,13 @@ unsigned long m48t37y_get_time(void) int m48t37y_set_time(unsigned long sec) { struct rtc_time tm; + unsigned long flags; /* convert to a more useful format -- note months count from 0 */ to_tm(sec, &tm); tm.tm_mon += 1; + spin_lock_irqsave(&rtc_lock, flags); /* enable writing */ m48t37_base->control = 0x80; @@ -123,6 +128,7 @@ int m48t37y_set_time(unsigned long sec) /* disable writing */ m48t37_base->control = 0x00; + spin_unlock_irqrestore(&rtc_lock, flags); return 0; } diff --git a/arch/mips/sgi-ip22/ip22-time.c b/arch/mips/sgi-ip22/ip22-time.c index df9b569432..b7300cc5c5 100644 --- a/arch/mips/sgi-ip22/ip22-time.c +++ b/arch/mips/sgi-ip22/ip22-time.c @@ -35,7 +35,9 @@ static unsigned long indy_rtc_get_time(void) { unsigned int yrs, mon, day, hrs, min, sec; unsigned int save_control; + unsigned long flags; + spin_lock_irqsave(&rtc_lock, flags); save_control = hpc3c0->rtcregs[RTC_CMD] & 0xff; hpc3c0->rtcregs[RTC_CMD] = save_control | RTC_TE; @@ -47,6 +49,7 @@ static unsigned long indy_rtc_get_time(void) yrs = BCD2BIN(hpc3c0->rtcregs[RTC_YEAR] & 0xff); hpc3c0->rtcregs[RTC_CMD] = save_control; + spin_unlock_irqrestore(&rtc_lock, flags); if (yrs < 45) yrs += 30; @@ -60,6 +63,7 @@ static int indy_rtc_set_time(unsigned long tim) { struct rtc_time tm; unsigned int save_control; + unsigned long flags; to_tm(tim, &tm); @@ -68,6 +72,7 @@ static int indy_rtc_set_time(unsigned long tim) if (tm.tm_year >= 100) tm.tm_year -= 100; + spin_lock_irqsave(&rtc_lock, flags); save_control = hpc3c0->rtcregs[RTC_CMD] & 0xff; hpc3c0->rtcregs[RTC_CMD] = save_control | RTC_TE; @@ -80,6 +85,7 @@ static int indy_rtc_set_time(unsigned long tim) hpc3c0->rtcregs[RTC_HUNDREDTH_SECOND] = 0; hpc3c0->rtcregs[RTC_CMD] = save_control; + spin_unlock_irqrestore(&rtc_lock, flags); return 0; } diff --git a/arch/mips/sibyte/swarm/rtc_m41t81.c b/arch/mips/sibyte/swarm/rtc_m41t81.c index 5b4fc26c1b..c13914bdda 100644 --- a/arch/mips/sibyte/swarm/rtc_m41t81.c +++ b/arch/mips/sibyte/swarm/rtc_m41t81.c @@ -144,6 +144,7 @@ static int m41t81_write(uint8_t addr, int b) int m41t81_set_time(unsigned long t) { struct rtc_time tm; + unsigned long flags; to_tm(t, &tm); @@ -153,6 +154,7 @@ int m41t81_set_time(unsigned long t) * believe we should finish writing min within a second. */ + spin_lock_irqsave(&rtc_lock, flags); tm.tm_sec = BIN2BCD(tm.tm_sec); m41t81_write(M41T81REG_SC, tm.tm_sec); @@ -180,6 +182,7 @@ int m41t81_set_time(unsigned long t) tm.tm_year %= 100; tm.tm_year = BIN2BCD(tm.tm_year); m41t81_write(M41T81REG_YR, tm.tm_year); + spin_unlock_irqrestore(&rtc_lock, flags); return 0; } @@ -187,19 +190,23 @@ int m41t81_set_time(unsigned long t) unsigned long m41t81_get_time(void) { unsigned int year, mon, day, hour, min, sec; + unsigned long flags; /* * min is valid if two reads of sec are the same. */ for (;;) { + spin_lock_irqsave(&rtc_lock, flags); sec = m41t81_read(M41T81REG_SC); min = m41t81_read(M41T81REG_MN); if (sec == m41t81_read(M41T81REG_SC)) break; + spin_unlock_irqrestore(&rtc_lock, flags); } hour = m41t81_read(M41T81REG_HR) & 0x3f; day = m41t81_read(M41T81REG_DT); mon = m41t81_read(M41T81REG_MO); year = m41t81_read(M41T81REG_YR); + spin_unlock_irqrestore(&rtc_lock, flags); sec = BCD2BIN(sec); min = BCD2BIN(min); diff --git a/arch/mips/sibyte/swarm/rtc_xicor1241.c b/arch/mips/sibyte/swarm/rtc_xicor1241.c index d9ff9323f2..f4a1788364 100644 --- a/arch/mips/sibyte/swarm/rtc_xicor1241.c +++ b/arch/mips/sibyte/swarm/rtc_xicor1241.c @@ -113,9 +113,11 @@ int xicor_set_time(unsigned long t) { struct rtc_time tm; int tmp; + unsigned long flags; to_tm(t, &tm); + spin_lock_irqsave(&rtc_lock, flags); /* unlock writes to the CCR */ xicor_write(X1241REG_SR, X1241REG_SR_WEL); xicor_write(X1241REG_SR, X1241REG_SR_WEL | X1241REG_SR_RWEL); @@ -160,6 +162,7 @@ int xicor_set_time(unsigned long t) xicor_write(X1241REG_HR, tmp); xicor_write(X1241REG_SR, 0); + spin_unlock_irqrestore(&rtc_lock, flags); return 0; } @@ -167,7 +170,9 @@ int xicor_set_time(unsigned long t) unsigned long xicor_get_time(void) { unsigned int year, mon, day, hour, min, sec, y2k; + unsigned long flags; + spin_lock_irqsave(&rtc_lock, flags); sec = xicor_read(X1241REG_SC); min = xicor_read(X1241REG_MN); hour = xicor_read(X1241REG_HR); @@ -183,6 +188,7 @@ unsigned long xicor_get_time(void) mon = xicor_read(X1241REG_MO); year = xicor_read(X1241REG_YR); y2k = xicor_read(X1241REG_Y2K); + spin_unlock_irqrestore(&rtc_lock, flags); sec = BCD2BIN(sec); min = BCD2BIN(min); diff --git a/include/asm-mips/mc146818-time.h b/include/asm-mips/mc146818-time.h index a2c2d2c243..4721486109 100644 --- a/include/asm-mips/mc146818-time.h +++ b/include/asm-mips/mc146818-time.h @@ -33,7 +33,9 @@ static inline int mc146818_set_rtc_mmss(unsigned long nowtime) int real_seconds, real_minutes, cmos_minutes; unsigned char save_control, save_freq_select; int retval = 0; + unsigned long flags; + spin_lock_irqsave(&rtc_lock, flags); save_control = CMOS_READ(RTC_CONTROL); /* tell the clock it's being set */ CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL); @@ -79,14 +81,30 @@ static inline int mc146818_set_rtc_mmss(unsigned long nowtime) */ CMOS_WRITE(save_control, RTC_CONTROL); CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); + spin_unlock_irqrestore(&rtc_lock, flags); return retval; } +/* + * Returns true if a clock update is in progress + */ +static inline unsigned char rtc_is_updating(void) +{ + unsigned char uip; + unsigned long flags; + + spin_lock_irqsave(&rtc_lock, flags); + uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP); + spin_unlock_irqrestore(&rtc_lock, flags); + return uip; +} + static inline unsigned long mc146818_get_cmos_time(void) { unsigned int year, mon, day, hour, min, sec; int i; + unsigned long flags; /* * The Linux interpretation of the CMOS clock register contents: @@ -97,12 +115,13 @@ static inline unsigned long mc146818_get_cmos_time(void) /* read RTC exactly on falling edge of update flag */ for (i = 0 ; i < 1000000 ; i++) /* may take up to 1 second... */ - if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP) + if (rtc_is_updating()) break; for (i = 0 ; i < 1000000 ; i++) /* must try at least 2.228 ms */ - if (!(CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP)) + if (!rtc_is_updating()) break; + spin_lock_irqsave(&rtc_lock, flags); do { /* Isn't this overkill ? UIP above should guarantee consistency */ sec = CMOS_READ(RTC_SECONDS); min = CMOS_READ(RTC_MINUTES); @@ -120,6 +139,7 @@ static inline unsigned long mc146818_get_cmos_time(void) BCD_TO_BIN(mon); BCD_TO_BIN(year); } + spin_unlock_irqrestore(&rtc_lock, flags); year = mc146818_decode_year(year); return mktime(year, mon, day, hour, min, sec); diff --git a/include/asm-mips/time.h b/include/asm-mips/time.h index e22a206658..9cc3564cc2 100644 --- a/include/asm-mips/time.h +++ b/include/asm-mips/time.h @@ -20,6 +20,9 @@ #include #include #include +#include + +extern spinlock_t rtc_lock; /* * RTC ops. By default, they point to no-RTC functions.