Patch "ARM: 9007/1: l2c: fix prefetch bits init in L2X0_AUX_CTRL using DT values" has been added to the 5.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    ARM: 9007/1: l2c: fix prefetch bits init in L2X0_AUX_CTRL using DT values

to the 5.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     arm-9007-1-l2c-fix-prefetch-bits-init-in-l2x0_aux_ct.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 0e7c0f5db529a170ee384ebbfb17ea8ca9b1b68f
Author: Guillaume Tucker <guillaume.tucker@xxxxxxxxxxxxx>
Date:   Tue Sep 1 16:58:06 2020 +0100

    ARM: 9007/1: l2c: fix prefetch bits init in L2X0_AUX_CTRL using DT values
    
    [ Upstream commit 8e007b367a59bcdf484c81f6df9bd5a4cc179ca6 ]
    
    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@xxxxxxxxxxxxx/
    
    Fixes: ec3bd0e68a67 ("ARM: 8391/1: l2c: add options to overwrite prefetching behavior")
    Signed-off-by: Guillaume Tucker <guillaume.tucker@xxxxxxxxxxxxx>
    Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index 12c26eb88afbc..43d91bfd23600 100644
--- 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 struct device_node *np,
 
 	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");
 	}