From 54954a6d6ba1c2f44375d2992d50f1db56a8857d Mon Sep 17 00:00:00 2001 From: David Daney Date: Thu, 7 Oct 2010 16:03:47 -0700 Subject: [PATCH] MIPS: Octeon: Scale Octeon2 clocks in octeon_init_cvmcount() The per-CPU clocks are synchronized from IPD_CLK_COUNT, on cn63XX it must be scaled by the clock frequency ratio. Signed-off-by: David Daney Patchwork: http://patchwork.linux-mips.org/patch/1667/ Signed-off-by: Ralf Baechle --- arch/mips/cavium-octeon/csrc-octeon.c | 34 ++++++++++++++++++++++++--- 1 file changed, 31 insertions(+), 3 deletions(-) diff --git a/arch/mips/cavium-octeon/csrc-octeon.c b/arch/mips/cavium-octeon/csrc-octeon.c index b6847c8e0ddd..26bf71130bf8 100644 --- a/arch/mips/cavium-octeon/csrc-octeon.c +++ b/arch/mips/cavium-octeon/csrc-octeon.c @@ -4,14 +4,18 @@ * for more details. * * Copyright (C) 2007 by Ralf Baechle + * Copyright (C) 2009, 2010 Cavium Networks, Inc. */ #include #include +#include +#include #include #include #include +#include /* * Set the current core's cvmcount counter to the value of the @@ -19,11 +23,23 @@ * 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) { unsigned long flags; unsigned loops = 2; + u64 f = 0; + u64 rdiv = 0; + u64 sdiv = 0; + 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; + } + /* Clobber loops so GCC will not unroll the following while loop. */ asm("" : "+r" (loops)); @@ -33,8 +49,20 @@ void octeon_init_cvmcount(void) * 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)); + while (loops--) { + u64 ipd_clk_count = cvmx_read_csr(CVMX_IPD_CLK_COUNT); + if (rdiv != 0) { + ipd_clk_count *= rdiv; + if (f != 0) { + asm("dmultu\t%[cnt],%[f]\n\t" + "mfhi\t%[cnt]" + : [cnt] "+r" (ipd_clk_count), + [f] "=r" (f) + : : "hi", "lo"); + } + } + write_c0_cvmcount(ipd_clk_count); + } local_irq_restore(flags); } @@ -77,7 +105,7 @@ unsigned long long notrace sched_clock(void) void __init plat_time_init(void) { clocksource_mips.rating = 300; - clocksource_set_clock(&clocksource_mips, mips_hpt_frequency); + clocksource_set_clock(&clocksource_mips, octeon_get_clock_rate()); clocksource_register(&clocksource_mips); } -- 2.20.1