From: Guillaume Tucker <guillaume.tucker@xxxxxxxxxxxxx> [ 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> --- arch/arm/mm/cache-l2x0.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) 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"); } -- 2.25.1
