diff options
author | David Daney <ddaney@caviumnetworks.com> | 2010-06-01 20:18:15 (GMT) |
---|---|---|
committer | Ralf Baechle <ralf@linux-mips.org> | 2010-08-05 12:26:20 (GMT) |
commit | ca148125e6134de334b61822539d220794d8da18 (patch) | |
tree | e31af5840a8873ec6613bf9b09fe0f9ad3e6a9c7 /arch/mips/cavium-octeon | |
parent | e6b78c4f224925c71cce57033b1e6e30dd56add7 (diff) | |
download | linux-ca148125e6134de334b61822539d220794d8da18.tar.xz |
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.c | 55 | ||||
-rw-r--r-- | arch/mips/cavium-octeon/setup.c | 4 |
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 36400d2..b6847c8 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 8c81a5c..7216fbd 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; |