From: Guillaume Tucker <guillaume.tucker@collabora.com>
Date: Tue, 1 Sep 2020 16:58:06 +0100
Subject: ARM: 9007/1: l2c: fix prefetch bits init in L2X0_AUX_CTRL using DT
 values
Git-commit: 8e007b367a59bcdf484c81f6df9bd5a4cc179ca6
Patch-mainline: v5.10-rc1
References: git-fixes

The L310_PREFETCH_CTRL register bits 28 and 29 to enable data and
instruction prefetch respectively can also be accessed via the
L2X0_AUX_CTRL register.  They appear to be actually wired together in
hardware between the registers.  Changing them in the prefetch
register only will get undone when restoring the aux control register
later on.  For this reason, set these bits in both registers during
initialisation according to the devicetree property values.

Link: https://lore.kernel.org/lkml/76f2f3ad5e77e356e0a5b99ceee1e774a2842c25.1597061474.git.guillaume.tucker@collabora.com/

Fixes: ec3bd0e68a67 ("ARM: 8391/1: l2c: add options to overwrite prefetching behavior")
Signed-off-by: Guillaume Tucker <guillaume.tucker@collabora.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Ivan T. Ivanov <iivanov@suse.de>
---
 arch/arm/mm/cache-l2x0.c |   16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -1249,20 +1249,28 @@ static void __init l2c310_of_parse(const
 
 	ret = of_property_read_u32(np, "prefetch-data", &val);
 	if (ret == 0) {
-		if (val)
+		if (val) {
 			prefetch |= L310_PREFETCH_CTRL_DATA_PREFETCH;
-		else
+			*aux_val |= L310_PREFETCH_CTRL_DATA_PREFETCH;
+		} else {
 			prefetch &= ~L310_PREFETCH_CTRL_DATA_PREFETCH;
+			*aux_val &= ~L310_PREFETCH_CTRL_DATA_PREFETCH;
+		}
+		*aux_mask &= ~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)
+		if (val) {
 			prefetch |= L310_PREFETCH_CTRL_INSTR_PREFETCH;
-		else
+			*aux_val |= L310_PREFETCH_CTRL_INSTR_PREFETCH;
+		} else {
 			prefetch &= ~L310_PREFETCH_CTRL_INSTR_PREFETCH;
+			*aux_val &= ~L310_PREFETCH_CTRL_INSTR_PREFETCH;
+		}
+		*aux_mask &= ~L310_PREFETCH_CTRL_INSTR_PREFETCH;
 	} else if (ret != -EINVAL) {
 		pr_err("L2C-310 OF prefetch-instr property value is missing\n");
 	}