arm64: dts: meson: Add capacity-dmips-mhz attributes to GXM

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GXM (S912) is a big-little design with CPUs 0-3 clocked at 1.5GHz
and CPUs 4-7 at 1.0GHz. Adding capacity-dmips-mhz attributes allows
the scheduler to factor the different clock speeds into capacity
calculations and prefer the higher-clocked cluster to improve
overall performance.

This was inspired by the similar change for G12B [0] boards. The
diference here is that all cores are A53's so the same dmips-mhz
value is used.

VIM2:~ # cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_cur_freq
1512000
1512000
1512000
1512000
1000000
1000000
1000000
1000000

before:

VIM2:~ # cat /sys/devices/system/cpu/cpu*/cpu_capacity
1024
1024
1024
1024
1024
1024
1024
1024

after:

VIM2:~ # cat /sys/devices/system/cpu/cpu*/cpu_capacity
1024
1024
1024
1024
677
677
677
677

The after value matches my table-napkin calculation:

(1000000 / 1512000 = 0.661) * 1024 = 677

[0] 6eeaf4d245

Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Link: https://lore.kernel.org/r/20201124121740.25704-1-christianshewitt@gmail.com

...

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Christian Hewitt 2020-11-24 12:17:40 +00:00 • committed by Kevin Hilman

parent 9715b01da6

commit 4592bfe9d9

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arch/arm64/boot/dts/amlogic/meson-gxm.dtsi

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