From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- arch/m68k/atari/time.c | 321 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 321 insertions(+) create mode 100644 arch/m68k/atari/time.c (limited to 'arch/m68k/atari/time.c') diff --git a/arch/m68k/atari/time.c b/arch/m68k/atari/time.c new file mode 100644 index 000000000..3453c6dc6 --- /dev/null +++ b/arch/m68k/atari/time.c @@ -0,0 +1,321 @@ +/* + * linux/arch/m68k/atari/time.c + * + * Atari time and real time clock stuff + * + * Assembled of parts of former atari/config.c 97-12-18 by Roman Hodek + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive + * for more details. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include "atari.h" + +DEFINE_SPINLOCK(rtc_lock); +EXPORT_SYMBOL_GPL(rtc_lock); + +static u64 atari_read_clk(struct clocksource *cs); + +static struct clocksource atari_clk = { + .name = "mfp", + .rating = 100, + .read = atari_read_clk, + .mask = CLOCKSOURCE_MASK(32), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static u32 clk_total; +static u8 last_timer_count; + +static irqreturn_t mfp_timer_c_handler(int irq, void *dev_id) +{ + unsigned long flags; + + local_irq_save(flags); + do { + last_timer_count = st_mfp.tim_dt_c; + } while (last_timer_count == 1); + clk_total += INT_TICKS; + legacy_timer_tick(1); + timer_heartbeat(); + local_irq_restore(flags); + + return IRQ_HANDLED; +} + +void __init +atari_sched_init(void) +{ + /* set Timer C data Register */ + st_mfp.tim_dt_c = INT_TICKS; + /* start timer C, div = 1:100 */ + st_mfp.tim_ct_cd = (st_mfp.tim_ct_cd & 15) | 0x60; + /* install interrupt service routine for MFP Timer C */ + if (request_irq(IRQ_MFP_TIMC, mfp_timer_c_handler, IRQF_TIMER, "timer", + NULL)) + pr_err("Couldn't register timer interrupt\n"); + + clocksource_register_hz(&atari_clk, INT_CLK); +} + +/* ++andreas: gettimeoffset fixed to check for pending interrupt */ + +static u64 atari_read_clk(struct clocksource *cs) +{ + unsigned long flags; + u8 count; + u32 ticks; + + local_irq_save(flags); + /* Ensure that the count is monotonically decreasing, even though + * the result may briefly stop changing after counter wrap-around. + */ + count = min(st_mfp.tim_dt_c, last_timer_count); + last_timer_count = count; + + ticks = INT_TICKS - count; + ticks += clk_total; + local_irq_restore(flags); + + return ticks; +} + + +static void mste_read(struct MSTE_RTC *val) +{ +#define COPY(v) val->v=(mste_rtc.v & 0xf) + do { + COPY(sec_ones) ; COPY(sec_tens) ; COPY(min_ones) ; + COPY(min_tens) ; COPY(hr_ones) ; COPY(hr_tens) ; + COPY(weekday) ; COPY(day_ones) ; COPY(day_tens) ; + COPY(mon_ones) ; COPY(mon_tens) ; COPY(year_ones) ; + COPY(year_tens) ; + /* prevent from reading the clock while it changed */ + } while (val->sec_ones != (mste_rtc.sec_ones & 0xf)); +#undef COPY +} + +static void mste_write(struct MSTE_RTC *val) +{ +#define COPY(v) mste_rtc.v=val->v + do { + COPY(sec_ones) ; COPY(sec_tens) ; COPY(min_ones) ; + COPY(min_tens) ; COPY(hr_ones) ; COPY(hr_tens) ; + COPY(weekday) ; COPY(day_ones) ; COPY(day_tens) ; + COPY(mon_ones) ; COPY(mon_tens) ; COPY(year_ones) ; + COPY(year_tens) ; + /* prevent from writing the clock while it changed */ + } while (val->sec_ones != (mste_rtc.sec_ones & 0xf)); +#undef COPY +} + +#define RTC_READ(reg) \ + ({ unsigned char __val; \ + (void) atari_writeb(reg,&tt_rtc.regsel); \ + __val = tt_rtc.data; \ + __val; \ + }) + +#define RTC_WRITE(reg,val) \ + do { \ + atari_writeb(reg,&tt_rtc.regsel); \ + tt_rtc.data = (val); \ + } while(0) + + +#define HWCLK_POLL_INTERVAL 5 + +int atari_mste_hwclk( int op, struct rtc_time *t ) +{ + int hour, year; + int hr24=0; + struct MSTE_RTC val; + + mste_rtc.mode=(mste_rtc.mode | 1); + hr24=mste_rtc.mon_tens & 1; + mste_rtc.mode=(mste_rtc.mode & ~1); + + if (op) { + /* write: prepare values */ + + val.sec_ones = t->tm_sec % 10; + val.sec_tens = t->tm_sec / 10; + val.min_ones = t->tm_min % 10; + val.min_tens = t->tm_min / 10; + hour = t->tm_hour; + if (!hr24) { + if (hour > 11) + hour += 20 - 12; + if (hour == 0 || hour == 20) + hour += 12; + } + val.hr_ones = hour % 10; + val.hr_tens = hour / 10; + val.day_ones = t->tm_mday % 10; + val.day_tens = t->tm_mday / 10; + val.mon_ones = (t->tm_mon+1) % 10; + val.mon_tens = (t->tm_mon+1) / 10; + year = t->tm_year - 80; + val.year_ones = year % 10; + val.year_tens = year / 10; + val.weekday = t->tm_wday; + mste_write(&val); + mste_rtc.mode=(mste_rtc.mode | 1); + val.year_ones = (year % 4); /* leap year register */ + mste_rtc.mode=(mste_rtc.mode & ~1); + } + else { + mste_read(&val); + t->tm_sec = val.sec_ones + val.sec_tens * 10; + t->tm_min = val.min_ones + val.min_tens * 10; + hour = val.hr_ones + val.hr_tens * 10; + if (!hr24) { + if (hour == 12 || hour == 12 + 20) + hour -= 12; + if (hour >= 20) + hour += 12 - 20; + } + t->tm_hour = hour; + t->tm_mday = val.day_ones + val.day_tens * 10; + t->tm_mon = val.mon_ones + val.mon_tens * 10 - 1; + t->tm_year = val.year_ones + val.year_tens * 10 + 80; + t->tm_wday = val.weekday; + } + return 0; +} + +int atari_tt_hwclk( int op, struct rtc_time *t ) +{ + int sec=0, min=0, hour=0, day=0, mon=0, year=0, wday=0; + unsigned long flags; + unsigned char ctrl; + int pm = 0; + + ctrl = RTC_READ(RTC_CONTROL); /* control registers are + * independent from the UIP */ + + if (op) { + /* write: prepare values */ + + sec = t->tm_sec; + min = t->tm_min; + hour = t->tm_hour; + day = t->tm_mday; + mon = t->tm_mon + 1; + year = t->tm_year - atari_rtc_year_offset; + wday = t->tm_wday + (t->tm_wday >= 0); + + if (!(ctrl & RTC_24H)) { + if (hour > 11) { + pm = 0x80; + if (hour != 12) + hour -= 12; + } + else if (hour == 0) + hour = 12; + } + + if (!(ctrl & RTC_DM_BINARY)) { + sec = bin2bcd(sec); + min = bin2bcd(min); + hour = bin2bcd(hour); + day = bin2bcd(day); + mon = bin2bcd(mon); + year = bin2bcd(year); + if (wday >= 0) + wday = bin2bcd(wday); + } + } + + /* Reading/writing the clock registers is a bit critical due to + * the regular update cycle of the RTC. While an update is in + * progress, registers 0..9 shouldn't be touched. + * The problem is solved like that: If an update is currently in + * progress (the UIP bit is set), the process sleeps for a while + * (50ms). This really should be enough, since the update cycle + * normally needs 2 ms. + * If the UIP bit reads as 0, we have at least 244 usecs until the + * update starts. This should be enough... But to be sure, + * additionally the RTC_SET bit is set to prevent an update cycle. + */ + + while( RTC_READ(RTC_FREQ_SELECT) & RTC_UIP ) { + if (in_atomic() || irqs_disabled()) + mdelay(1); + else + schedule_timeout_interruptible(HWCLK_POLL_INTERVAL); + } + + local_irq_save(flags); + RTC_WRITE( RTC_CONTROL, ctrl | RTC_SET ); + if (!op) { + sec = RTC_READ( RTC_SECONDS ); + min = RTC_READ( RTC_MINUTES ); + hour = RTC_READ( RTC_HOURS ); + day = RTC_READ( RTC_DAY_OF_MONTH ); + mon = RTC_READ( RTC_MONTH ); + year = RTC_READ( RTC_YEAR ); + wday = RTC_READ( RTC_DAY_OF_WEEK ); + } + else { + RTC_WRITE( RTC_SECONDS, sec ); + RTC_WRITE( RTC_MINUTES, min ); + RTC_WRITE( RTC_HOURS, hour + pm); + RTC_WRITE( RTC_DAY_OF_MONTH, day ); + RTC_WRITE( RTC_MONTH, mon ); + RTC_WRITE( RTC_YEAR, year ); + if (wday >= 0) RTC_WRITE( RTC_DAY_OF_WEEK, wday ); + } + RTC_WRITE( RTC_CONTROL, ctrl & ~RTC_SET ); + local_irq_restore(flags); + + if (!op) { + /* read: adjust values */ + + if (hour & 0x80) { + hour &= ~0x80; + pm = 1; + } + + if (!(ctrl & RTC_DM_BINARY)) { + sec = bcd2bin(sec); + min = bcd2bin(min); + hour = bcd2bin(hour); + day = bcd2bin(day); + mon = bcd2bin(mon); + year = bcd2bin(year); + wday = bcd2bin(wday); + } + + if (!(ctrl & RTC_24H)) { + if (!pm && hour == 12) + hour = 0; + else if (pm && hour != 12) + hour += 12; + } + + t->tm_sec = sec; + t->tm_min = min; + t->tm_hour = hour; + t->tm_mday = day; + t->tm_mon = mon - 1; + t->tm_year = year + atari_rtc_year_offset; + t->tm_wday = wday - 1; + } + + return( 0 ); +} -- cgit v1.3.1