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authorDavid Daney <ddaney@caviumnetworks.com>2010-06-01 13:18:15 -0700
committerRalf Baechle <ralf@linux-mips.org>2010-08-05 13:26:20 +0100
commitca148125e6134de334b61822539d220794d8da18 (patch)
treee31af5840a8873ec6613bf9b09fe0f9ad3e6a9c7 /arch/mips/cavium-octeon
parente6b78c4f224925c71cce57033b1e6e30dd56add7 (diff)
MIPS: Octeon: Implement delays with cycle counter.
Power throttling make deterministic delay loops impossible. Re-implement delays using the cycle counter. This also allows us to get rid of the code that calculates loops per jiffy. Signed-off-by: David Daney <ddaney@caviumnetworks.com> To: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/1317/ 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.c55
-rw-r--r--arch/mips/cavium-octeon/setup.c4
2 files changed, 57 insertions, 2 deletions
diff --git a/arch/mips/cavium-octeon/csrc-octeon.c b/arch/mips/cavium-octeon/csrc-octeon.c
index 36400d23ff5..b6847c8e0dd 100644
--- a/arch/mips/cavium-octeon/csrc-octeon.c
+++ b/arch/mips/cavium-octeon/csrc-octeon.c
@@ -80,3 +80,58 @@ void __init plat_time_init(void)
clocksource_set_clock(&clocksource_mips, mips_hpt_frequency);
clocksource_register(&clocksource_mips);
}
+
+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;
+}
+
+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);
diff --git a/arch/mips/cavium-octeon/setup.c b/arch/mips/cavium-octeon/setup.c
index 8c81a5c5bba..7216fbd5d79 100644
--- a/arch/mips/cavium-octeon/setup.c
+++ b/arch/mips/cavium-octeon/setup.c
@@ -594,13 +594,13 @@ void __init prom_init(void)
* the filesystem. Also specify the calibration delay
* to avoid calculating it every time.
*/
- strcat(arcs_cmdline, " rw root=1f00"
- " lpj=60176 slram=root,0x40000000,+1073741824");
+ strcat(arcs_cmdline, " rw root=1f00 slram=root,0x40000000,+1073741824");
}
mips_hpt_frequency = octeon_get_clock_rate();
octeon_init_cvmcount();
+ octeon_setup_delays();
_machine_restart = octeon_restart;
_machine_halt = octeon_halt;