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authorDavid Daney <ddaney@caviumnetworks.com>2010-10-07 16:03:47 -0700
committerRalf Baechle <ralf@linux-mips.org>2010-10-29 19:08:38 +0100
commit54954a6d6ba1c2f44375d2992d50f1db56a8857d (patch)
tree332959aa2067a9b8819cf9ccd8e735abb78d88cb /arch/mips/cavium-octeon
parentf92a6b0875977132074a696e8d44c95e8472d8ac (diff)
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 <ddaney@caviumnetworks.com> Patchwork: http://patchwork.linux-mips.org/patch/1667/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/cavium-octeon')
-rw-r--r--arch/mips/cavium-octeon/csrc-octeon.c34
1 files changed, 31 insertions, 3 deletions
diff --git a/arch/mips/cavium-octeon/csrc-octeon.c b/arch/mips/cavium-octeon/csrc-octeon.c
index b6847c8e0dd..26bf71130bf 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 <linux/clocksource.h>
#include <linux/init.h>
+#include <linux/smp.h>
+#include <asm/cpu-info.h>
#include <asm/time.h>
#include <asm/octeon/octeon.h>
#include <asm/octeon/cvmx-ipd-defs.h>
+#include <asm/octeon/cvmx-mio-defs.h>
/*
* 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);
}