From 560be6136b3605ebbb8bd04b49b175c809d4e953 Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 17 Mar 2014 17:02:56 +0000 Subject: [PATCH] ARM: l2c: add warnings for stuff modifying aux_ctrl register values Signed-off-by: Russell King --- arch/arm/mm/cache-l2x0.c | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c index 415efc3bee0d..e99a0ffd22d1 100644 --- a/arch/arm/mm/cache-l2x0.c +++ b/arch/arm/mm/cache-l2x0.c @@ -755,13 +755,24 @@ static void __init __l2c_init(const struct l2c_init_data *data, { struct outer_cache_fns fns; unsigned way_size_bits, ways; - u32 aux; + u32 aux, old_aux; - aux = readl_relaxed(l2x0_base + L2X0_AUX_CTRL); + /* + * Sanity check the aux values. aux_mask is the bits we preserve + * from reading the hardware register, and aux_val is the bits we + * set. + */ + if (aux_val & aux_mask) + pr_alert("L2C: platform provided aux values permit register corruption.\n"); + old_aux = aux = readl_relaxed(l2x0_base + L2X0_AUX_CTRL); aux &= aux_mask; aux |= aux_val; + if (old_aux != aux) + pr_warn("L2C: DT/platform modifies aux control register: 0x%08x -> 0x%08x\n", + old_aux, aux); + /* Determine the number of ways */ switch (cache_id & L2X0_CACHE_ID_PART_MASK) { case L2X0_CACHE_ID_PART_L310: @@ -1392,7 +1403,7 @@ int __init l2x0_of_init(u32 aux_val, u32 aux_mask) const struct l2c_init_data *data; struct device_node *np; struct resource res; - u32 cache_id; + u32 cache_id, old_aux; np = of_find_matching_node(NULL, l2x0_ids); if (!np) @@ -1409,6 +1420,14 @@ int __init l2x0_of_init(u32 aux_val, u32 aux_mask) data = of_match_node(l2x0_ids, np)->data; + old_aux = readl_relaxed(l2x0_base + L2X0_AUX_CTRL); + if (old_aux != ((old_aux & aux_mask) | aux_val)) { + pr_warn("L2C: platform modifies aux control register: 0x%08x -> 0x%08x\n", + old_aux, (old_aux & aux_mask) | aux_val); + } else if (aux_mask != ~0U && aux_val != 0) { + pr_alert("L2C: platform provided aux values match the hardware, so have no effect. Please remove them.\n"); + } + /* All L2 caches are unified, so this property should be specified */ if (!of_property_read_bool(np, "cache-unified")) pr_err("L2C: device tree omits to specify unified cache\n"); -- 2.11.0