Date: Thu, 27 Feb 2020 15:21:06 +0000 (UTC) From: Hans Petter Selasky <hselasky@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r358387 - in head/sys/compat/linuxkpi/common: include/linux src Message-ID: <202002271521.01RFL6XL079909@repo.freebsd.org>
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Author: hselasky Date: Thu Feb 27 15:21:05 2020 New Revision: 358387 URL: https://svnweb.freebsd.org/changeset/base/358387 Log: Extend the range of the return value from nsecs_to_jiffies64() to support Mesa's drm_syncobj usage, in the LinuxKPI. While at it optimise the jiffies conversion functions to avoid repeated and constant calculations. Submitted by: Greg V <greg@unrelenting.technology> Differential Revision: https://reviews.freebsd.org/D23846 MFC after: 1 week Sponsored by: Mellanox Technologies Modified: head/sys/compat/linuxkpi/common/include/linux/jiffies.h head/sys/compat/linuxkpi/common/src/linux_compat.c Modified: head/sys/compat/linuxkpi/common/include/linux/jiffies.h ============================================================================== --- head/sys/compat/linuxkpi/common/include/linux/jiffies.h Thu Feb 27 15:08:43 2020 (r358386) +++ head/sys/compat/linuxkpi/common/include/linux/jiffies.h Thu Feb 27 15:21:05 2020 (r358387) @@ -54,6 +54,18 @@ #define HZ hz +extern uint64_t lkpi_nsec2hz_rem; +extern uint64_t lkpi_nsec2hz_div; +extern uint64_t lkpi_nsec2hz_max; + +extern uint64_t lkpi_usec2hz_rem; +extern uint64_t lkpi_usec2hz_div; +extern uint64_t lkpi_usec2hz_max; + +extern uint64_t lkpi_msec2hz_rem; +extern uint64_t lkpi_msec2hz_div; +extern uint64_t lkpi_msec2hz_max; + static inline int timespec_to_jiffies(const struct timespec *ts) { @@ -70,12 +82,11 @@ timespec_to_jiffies(const struct timespec *ts) static inline int msecs_to_jiffies(uint64_t msec) { - uint64_t msec_max, result; + uint64_t result; - msec_max = -1ULL / (uint64_t)hz; - if (msec > msec_max) - msec = msec_max; - result = howmany(msec * (uint64_t)hz, 1000ULL); + if (msec > lkpi_msec2hz_max) + msec = lkpi_msec2hz_max; + result = howmany(msec * lkpi_msec2hz_rem, lkpi_msec2hz_div); if (result > MAX_JIFFY_OFFSET) result = MAX_JIFFY_OFFSET; @@ -85,12 +96,11 @@ msecs_to_jiffies(uint64_t msec) static inline int usecs_to_jiffies(uint64_t usec) { - uint64_t usec_max, result; + uint64_t result; - usec_max = -1ULL / (uint64_t)hz; - if (usec > usec_max) - usec = usec_max; - result = howmany(usec * (uint64_t)hz, 1000000ULL); + if (usec > lkpi_usec2hz_max) + usec = lkpi_usec2hz_max; + result = howmany(usec * lkpi_usec2hz_rem, lkpi_usec2hz_div); if (result > MAX_JIFFY_OFFSET) result = MAX_JIFFY_OFFSET; @@ -100,23 +110,24 @@ usecs_to_jiffies(uint64_t usec) static inline uint64_t nsecs_to_jiffies64(uint64_t nsec) { - uint64_t nsec_max, result; - nsec_max = -1ULL / (uint64_t)hz; - if (nsec > nsec_max) - nsec = nsec_max; - result = howmany(nsec * (uint64_t)hz, 1000000000ULL); - if (result > MAX_JIFFY_OFFSET) - result = MAX_JIFFY_OFFSET; - - return (result); + if (nsec > lkpi_nsec2hz_max) + nsec = lkpi_nsec2hz_max; + return (howmany(nsec * lkpi_nsec2hz_rem, lkpi_nsec2hz_div)); } -static inline uint64_t -nsecs_to_jiffies(uint64_t n) +static inline unsigned long +nsecs_to_jiffies(uint64_t nsec) { - return (usecs_to_jiffies(howmany(n, 1000ULL))); + if (sizeof(unsigned long) >= sizeof(uint64_t)) { + if (nsec > lkpi_nsec2hz_max) + nsec = lkpi_nsec2hz_max; + } else { + if (nsec > (lkpi_nsec2hz_max >> 32)) + nsec = (lkpi_nsec2hz_max >> 32); + } + return (howmany(nsec * lkpi_nsec2hz_rem, lkpi_nsec2hz_div)); } static inline uint64_t Modified: head/sys/compat/linuxkpi/common/src/linux_compat.c ============================================================================== --- head/sys/compat/linuxkpi/common/src/linux_compat.c Thu Feb 27 15:08:43 2020 (r358386) +++ head/sys/compat/linuxkpi/common/src/linux_compat.c Thu Feb 27 15:21:05 2020 (r358387) @@ -1934,9 +1934,38 @@ del_timer(struct timer_list *timer) return (1); } +/* greatest common divisor, Euclid equation */ +static uint64_t +lkpi_gcd_64(uint64_t a, uint64_t b) +{ + uint64_t an; + uint64_t bn; + + while (b != 0) { + an = b; + bn = a % b; + a = an; + b = bn; + } + return (a); +} + +uint64_t lkpi_nsec2hz_rem; +uint64_t lkpi_nsec2hz_div = 1000000000ULL; +uint64_t lkpi_nsec2hz_max; + +uint64_t lkpi_usec2hz_rem; +uint64_t lkpi_usec2hz_div = 1000000ULL; +uint64_t lkpi_usec2hz_max; + +uint64_t lkpi_msec2hz_rem; +uint64_t lkpi_msec2hz_div = 1000ULL; +uint64_t lkpi_msec2hz_max; + static void linux_timer_init(void *arg) { + uint64_t gcd; /* * Compute an internal HZ value which can divide 2**32 to @@ -1947,6 +1976,27 @@ linux_timer_init(void *arg) while (linux_timer_hz_mask < (unsigned long)hz) linux_timer_hz_mask *= 2; linux_timer_hz_mask--; + + /* compute some internal constants */ + + lkpi_nsec2hz_rem = hz; + lkpi_usec2hz_rem = hz; + lkpi_msec2hz_rem = hz; + + gcd = lkpi_gcd_64(lkpi_nsec2hz_rem, lkpi_nsec2hz_div); + lkpi_nsec2hz_rem /= gcd; + lkpi_nsec2hz_div /= gcd; + lkpi_nsec2hz_max = -1ULL / lkpi_nsec2hz_rem; + + gcd = lkpi_gcd_64(lkpi_usec2hz_rem, lkpi_usec2hz_div); + lkpi_usec2hz_rem /= gcd; + lkpi_usec2hz_div /= gcd; + lkpi_usec2hz_max = -1ULL / lkpi_usec2hz_rem; + + gcd = lkpi_gcd_64(lkpi_msec2hz_rem, lkpi_msec2hz_div); + lkpi_msec2hz_rem /= gcd; + lkpi_msec2hz_div /= gcd; + lkpi_msec2hz_max = -1ULL / lkpi_msec2hz_rem; } SYSINIT(linux_timer, SI_SUB_DRIVERS, SI_ORDER_FIRST, linux_timer_init, NULL);
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