diff options
Diffstat (limited to 'arch/mips/cavium-octeon/csrc-octeon.c')
-rw-r--r-- | arch/mips/cavium-octeon/csrc-octeon.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/arch/mips/cavium-octeon/csrc-octeon.c b/arch/mips/cavium-octeon/csrc-octeon.c new file mode 100644 index 000000000000..70fd92c31657 --- /dev/null +++ b/arch/mips/cavium-octeon/csrc-octeon.c @@ -0,0 +1,58 @@ +/* + * 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. + * + * Copyright (C) 2007 by Ralf Baechle + */ +#include <linux/clocksource.h> +#include <linux/init.h> + +#include <asm/time.h> + +#include <asm/octeon/octeon.h> +#include <asm/octeon/cvmx-ipd-defs.h> + +/* + * Set the current core's cvmcount counter to the value of the + * IPD_CLK_COUNT. We do this on all cores as they are brought + * on-line. This allows for a read from a local cpu register to + * access a synchronized counter. + * + */ +void octeon_init_cvmcount(void) +{ + unsigned long flags; + unsigned loops = 2; + + /* Clobber loops so GCC will not unroll the following while loop. */ + asm("" : "+r" (loops)); + + local_irq_save(flags); + /* + * Loop several times so we are executing from the cache, + * which should give more deterministic timing. + */ + while (loops--) + write_c0_cvmcount(cvmx_read_csr(CVMX_IPD_CLK_COUNT)); + local_irq_restore(flags); +} + +static cycle_t octeon_cvmcount_read(void) +{ + return read_c0_cvmcount(); +} + +static struct clocksource clocksource_mips = { + .name = "OCTEON_CVMCOUNT", + .read = octeon_cvmcount_read, + .mask = CLOCKSOURCE_MASK(64), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +void __init plat_time_init(void) +{ + clocksource_mips.rating = 300; + clocksource_set_clock(&clocksource_mips, mips_hpt_frequency); + clocksource_register(&clocksource_mips); +} |