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Revert r330780, it was improperly tested and results in taking a spin

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mutex before acquiring sleep mutexes.

Reported by:	kib@
This commit is contained in:
Ian Lepore 2018-03-11 20:13:15 +00:00
parent 4b502f0016
commit c7053bbe54
3 changed files with 15 additions and 10 deletions
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6
sys/amd64/include/efi.h
View File

@ -48,9 +48,9 @@
#ifdef _KERNEL
#include <isa/rtc.h>
#define EFI_TIME_LOCK() mtx_lock_spin(&atrtc_lock);
#define EFI_TIME_UNLOCK() mtx_unlock_spin(&atrtc_lock);
#define EFI_TIME_OWNED() mtx_assert(&atrtc_lock, MA_OWNED);
#define EFI_TIME_LOCK() mtx_lock(&atrtc_time_lock);
#define EFI_TIME_UNLOCK() mtx_unlock(&atrtc_time_lock);
#define EFI_TIME_OWNED() mtx_assert(&atrtc_time_lock, MA_OWNED);
#endif
#endif /* __AMD64_INCLUDE_EFI_H_ */

2
sys/isa/rtc.h
View File

@ -114,7 +114,7 @@
#define RTC_CENTURY 0x32 /* current century */
#ifdef _KERNEL
extern struct mtx atrtc_lock;
extern struct mtx atrtc_time_lock;
extern int atrtcclock_disable;
int rtcin(int reg);
void atrtc_restore(void);

17
sys/x86/isa/atrtc.c
View File

@ -56,15 +56,16 @@ __FBSDID("$FreeBSD$");
#include "clock_if.h"
/*
* atrtc_lock protects access to the RTC ioports, which are accessed by this
* driver, the nvram(4) driver (via rtcin()/writertc() calls), and the rtc code
* in efi runtime services. The efirt wrapper code directly locks atrtc lock
* using the EFI_TIME_LOCK/UNLOCK() macros which are defined to use this mutex
* on x86 platforms.
* atrtc_lock protects low-level access to individual hardware registers.
* atrtc_time_lock protects the entire sequence of accessing multiple registers
* to read or write the date and time.
*/
struct mtx atrtc_lock;
static struct mtx atrtc_lock;
MTX_SYSINIT(atrtc_lock_init, &atrtc_lock, "atrtc", MTX_SPIN);
struct mtx atrtc_time_lock;
MTX_SYSINIT(atrtc_time_lock_init, &atrtc_time_lock, "atrtc", MTX_DEF);
int atrtcclock_disable = 0;
static int rtc_reg = -1;
@ -327,6 +328,7 @@ atrtc_settime(device_t dev __unused, struct timespec *ts)
clock_ts_to_bcd(ts, &bct, false);
clock_dbgprint_bcd(dev, CLOCK_DBG_WRITE, &bct);
mtx_lock(&atrtc_time_lock);
mtx_lock_spin(&atrtc_lock);
/* Disable RTC updates and interrupts. */
@ -351,6 +353,7 @@ atrtc_settime(device_t dev __unused, struct timespec *ts)
rtcin_locked(RTC_INTR);
mtx_unlock_spin(&atrtc_lock);
mtx_unlock(&atrtc_time_lock);
return (0);
}
@ -373,6 +376,7 @@ atrtc_gettime(device_t dev, struct timespec *ts)
* to make sure that no more than 240us pass after we start reading,
* and try again if so.
*/
mtx_lock(&atrtc_time_lock);
while (rtcin(RTC_STATUSA) & RTCSA_TUP)
continue;
mtx_lock_spin(&atrtc_lock);
@ -386,6 +390,7 @@ atrtc_gettime(device_t dev, struct timespec *ts)
bct.year |= rtcin_locked(RTC_CENTURY) << 8;
#endif
mtx_unlock_spin(&atrtc_lock);
mtx_unlock(&atrtc_time_lock);
/* dow is unused in timespec conversion and we have no nsec info. */
bct.dow = 0;
bct.nsec = 0;