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Commit ec3bd0e6 authored by Hauke Mehrtens's avatar Hauke Mehrtens Committed by Russell King
Browse files

ARM: 8391/1: l2c: add options to overwrite prefetching behavior 



These options make it possible to overwrites the data and instruction
prefetching behavior of the arm pl310 cache controller.

Signed-off-by: default avatarHauke Mehrtens <hauke@hauke-m.de>
Acked-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 55af8a91

Documentation/devicetree/bindings/arm/l2cc.txt

+5 −0
Original line number Diff line number Diff line
@@ -67,6 +67,11 @@ Optional properties: 
  disable if zero.

- arm,prefetch-offset : Override prefetch offset value. Valid values are

  0-7, 15, 23, and 31.

- prefetch-data : Data prefetch. Value: <0> (forcibly disable), <1>

  (forcibly enable), property absent (retain settings set by firmware)

- prefetch-instr : Instruction prefetch. Value: <0> (forcibly disable),

  <1> (forcibly enable), property absent (retain settings set by

  firmware)



Example:

arch/arm/mm/cache-l2x0.c

+20 −0
Original line number Diff line number Diff line
@@ -1221,6 +1221,26 @@ static void __init l2c310_of_parse(const struct device_node *np, 
		pr_err("L2C-310 OF arm,prefetch-offset property value is missing\n");

	}



	ret = of_property_read_u32(np, "prefetch-data", &val);

	if (ret == 0) {

		if (val)

			prefetch |= L310_PREFETCH_CTRL_DATA_PREFETCH;

		else

			prefetch &= ~L310_PREFETCH_CTRL_DATA_PREFETCH;

	} else if (ret != -EINVAL) {

		pr_err("L2C-310 OF prefetch-data property value is missing\n");

	}



	ret = of_property_read_u32(np, "prefetch-instr", &val);

	if (ret == 0) {

		if (val)

			prefetch |= L310_PREFETCH_CTRL_INSTR_PREFETCH;

		else

			prefetch &= ~L310_PREFETCH_CTRL_INSTR_PREFETCH;

	} else if (ret != -EINVAL) {

		pr_err("L2C-310 OF prefetch-instr property value is missing\n");

	}



	l2x0_saved_regs.prefetch_ctrl = prefetch;

}