ARM: tegra: only run PL310 init on systems with one
Fix tegra_init_cache() to check whether the system has a PL310 cache
before touching the PL310 registers. This prevents access to non-existent
registers on Tegra114 and later.
Note for stable kernels:
In <= v3.12, the file to patch is arch/arm/mach-tegra/common.c.
Cc: <stable@vger.kernel.org> # v3.9+
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
diff --git a/arch/arm/mach-tegra/tegra.c b/arch/arm/mach-tegra/tegra.c
index 303a285..6191603 100644
--- a/arch/arm/mach-tegra/tegra.c
+++ b/arch/arm/mach-tegra/tegra.c
@@ -73,10 +73,20 @@
static void __init tegra_init_cache(void)
{
#ifdef CONFIG_CACHE_L2X0
+ static const struct of_device_id pl310_ids[] __initconst = {
+ { .compatible = "arm,pl310-cache", },
+ {}
+ };
+
+ struct device_node *np;
int ret;
void __iomem *p = IO_ADDRESS(TEGRA_ARM_PERIF_BASE) + 0x3000;
u32 aux_ctrl, cache_type;
+ np = of_find_matching_node(NULL, pl310_ids);
+ if (!np)
+ return;
+
cache_type = readl(p + L2X0_CACHE_TYPE);
aux_ctrl = (cache_type & 0x700) << (17-8);
aux_ctrl |= 0x7C400001;