diff options
Diffstat (limited to 'arch/mips/cavium-octeon/csrc-octeon.c')
| -rw-r--r-- | arch/mips/cavium-octeon/csrc-octeon.c | 213 |
1 files changed, 213 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 000000000..39f153fe0 --- /dev/null +++ b/arch/mips/cavium-octeon/csrc-octeon.c @@ -0,0 +1,213 @@ +/* + * 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 + * Copyright (C) 2009, 2012 Cavium, Inc. + */ +#include <linux/clocksource.h> +#include <linux/export.h> +#include <linux/init.h> +#include <linux/smp.h> + +#include <asm/cpu-info.h> +#include <asm/cpu-type.h> +#include <asm/time.h> + +#include <asm/octeon/octeon.h> +#include <asm/octeon/cvmx-ipd-defs.h> +#include <asm/octeon/cvmx-mio-defs.h> +#include <asm/octeon/cvmx-rst-defs.h> +#include <asm/octeon/cvmx-fpa-defs.h> + +static u64 f; +static u64 rdiv; +static u64 sdiv; +static u64 octeon_udelay_factor; +static u64 octeon_ndelay_factor; + +void __init octeon_setup_delays(void) +{ + octeon_udelay_factor = octeon_get_clock_rate() / 1000000; + /* + * For __ndelay we divide by 2^16, so the factor is multiplied + * by the same amount. + */ + octeon_ndelay_factor = (octeon_udelay_factor * 0x10000ull) / 1000ull; + + preset_lpj = octeon_get_clock_rate() / HZ; + + if (current_cpu_type() == CPU_CAVIUM_OCTEON2) { + union cvmx_mio_rst_boot rst_boot; + + rst_boot.u64 = cvmx_read_csr(CVMX_MIO_RST_BOOT); + rdiv = rst_boot.s.c_mul; /* CPU clock */ + sdiv = rst_boot.s.pnr_mul; /* I/O clock */ + f = (0x8000000000000000ull / sdiv) * 2; + } else if (current_cpu_type() == CPU_CAVIUM_OCTEON3) { + union cvmx_rst_boot rst_boot; + + rst_boot.u64 = cvmx_read_csr(CVMX_RST_BOOT); + rdiv = rst_boot.s.c_mul; /* CPU clock */ + sdiv = rst_boot.s.pnr_mul; /* I/O clock */ + f = (0x8000000000000000ull / sdiv) * 2; + } + +} + +/* + * 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. + * + * On CPU_CAVIUM_OCTEON2 the IPD_CLK_COUNT is scaled by rdiv/sdiv. + */ +void octeon_init_cvmcount(void) +{ + u64 clk_reg; + unsigned long flags; + unsigned loops = 2; + + clk_reg = octeon_has_feature(OCTEON_FEATURE_FPA3) ? + CVMX_FPA_CLK_COUNT : CVMX_IPD_CLK_COUNT; + + /* 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--) { + u64 clk_count = cvmx_read_csr(clk_reg); + if (rdiv != 0) { + clk_count *= rdiv; + if (f != 0) { + asm("dmultu\t%[cnt],%[f]\n\t" + "mfhi\t%[cnt]" + : [cnt] "+r" (clk_count) + : [f] "r" (f) + : "hi", "lo"); + } + } + write_c0_cvmcount(clk_count); + } + local_irq_restore(flags); +} + +static u64 octeon_cvmcount_read(struct clocksource *cs) +{ + 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, +}; + +unsigned long long notrace sched_clock(void) +{ + /* 64-bit arithmatic can overflow, so use 128-bit. */ + u64 t1, t2, t3; + unsigned long long rv; + u64 mult = clocksource_mips.mult; + u64 shift = clocksource_mips.shift; + u64 cnt = read_c0_cvmcount(); + + asm ( + "dmultu\t%[cnt],%[mult]\n\t" + "nor\t%[t1],$0,%[shift]\n\t" + "mfhi\t%[t2]\n\t" + "mflo\t%[t3]\n\t" + "dsll\t%[t2],%[t2],1\n\t" + "dsrlv\t%[rv],%[t3],%[shift]\n\t" + "dsllv\t%[t1],%[t2],%[t1]\n\t" + "or\t%[rv],%[t1],%[rv]\n\t" + : [rv] "=&r" (rv), [t1] "=&r" (t1), [t2] "=&r" (t2), [t3] "=&r" (t3) + : [cnt] "r" (cnt), [mult] "r" (mult), [shift] "r" (shift) + : "hi", "lo"); + return rv; +} + +void __init plat_time_init(void) +{ + clocksource_mips.rating = 300; + clocksource_register_hz(&clocksource_mips, octeon_get_clock_rate()); +} + +void __udelay(unsigned long us) +{ + u64 cur, end, inc; + + cur = read_c0_cvmcount(); + + inc = us * octeon_udelay_factor; + end = cur + inc; + + while (end > cur) + cur = read_c0_cvmcount(); +} +EXPORT_SYMBOL(__udelay); + +void __ndelay(unsigned long ns) +{ + u64 cur, end, inc; + + cur = read_c0_cvmcount(); + + inc = ((ns * octeon_ndelay_factor) >> 16); + end = cur + inc; + + while (end > cur) + cur = read_c0_cvmcount(); +} +EXPORT_SYMBOL(__ndelay); + +void __delay(unsigned long loops) +{ + u64 cur, end; + + cur = read_c0_cvmcount(); + end = cur + loops; + + while (end > cur) + cur = read_c0_cvmcount(); +} +EXPORT_SYMBOL(__delay); + + +/** + * octeon_io_clk_delay - wait for a given number of io clock cycles to pass. + * + * We scale the wait by the clock ratio, and then wait for the + * corresponding number of core clocks. + * + * @count: The number of clocks to wait. + */ +void octeon_io_clk_delay(unsigned long count) +{ + u64 cur, end; + + cur = read_c0_cvmcount(); + if (rdiv != 0) { + end = count * rdiv; + if (f != 0) { + asm("dmultu\t%[cnt],%[f]\n\t" + "mfhi\t%[cnt]" + : [cnt] "+r" (end) + : [f] "r" (f) + : "hi", "lo"); + } + end = cur + end; + } else { + end = cur + count; + } + while (end > cur) + cur = read_c0_cvmcount(); +} +EXPORT_SYMBOL(octeon_io_clk_delay); |