diff --git a/Documentation/devicetree/bindings/arm/mvebu-cpu-config.txt b/Documentation/devicetree/bindings/arm/mvebu-cpu-config.txt new file mode 100644 index 000000000000..2cdcd716da40 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/mvebu-cpu-config.txt @@ -0,0 +1,20 @@ +MVEBU CPU Config registers +-------------------------- + +MVEBU (Marvell SOCs: Armada 370/XP) + +Required properties: + +- compatible: one of: + - "marvell,armada-370-cpu-config" + - "marvell,armada-xp-cpu-config" + +- reg: Should contain CPU config registers location and length, in + their per-CPU variant + +Example: + + cpu-config@21000 { + compatible = "marvell,armada-xp-cpu-config"; + reg = <0x21000 0x8>; + }; diff --git a/arch/arm/mach-mvebu/coherency.c b/arch/arm/mach-mvebu/coherency.c index 44eedf331ae7..55348ee5a352 100644 --- a/arch/arm/mach-mvebu/coherency.c +++ b/arch/arm/mach-mvebu/coherency.c @@ -40,6 +40,7 @@ unsigned long coherency_phys_base; void __iomem *coherency_base; static void __iomem *coherency_cpu_base; +static void __iomem *cpu_config_base; /* Coherency fabric registers */ #define IO_SYNC_BARRIER_CTL_OFFSET 0x0 @@ -65,6 +66,31 @@ static const struct of_device_id of_coherency_table[] = { int ll_enable_coherency(void); void ll_add_cpu_to_smp_group(void); +#define CPU_CONFIG_SHARED_L2 BIT(16) + +/* + * Disable the "Shared L2 Present" bit in CPU Configuration register + * on Armada XP. + * + * The "Shared L2 Present" bit affects the "level of coherence" value + * in the clidr CP15 register. Cache operation functions such as + * "flush all" and "invalidate all" operate on all the cache levels + * that included in the defined level of coherence. When HW I/O + * coherency is used, this bit causes unnecessary flushes of the L2 + * cache. + */ +static void armada_xp_clear_shared_l2(void) +{ + u32 reg; + + if (!cpu_config_base) + return; + + reg = readl(cpu_config_base); + reg &= ~CPU_CONFIG_SHARED_L2; + writel(reg, cpu_config_base); +} + static int mvebu_hwcc_notifier(struct notifier_block *nb, unsigned long event, void *__dev) { @@ -85,9 +111,24 @@ static struct notifier_block mvebu_hwcc_pci_nb = { .notifier_call = mvebu_hwcc_notifier, }; +static int armada_xp_clear_shared_l2_notifier_func(struct notifier_block *nfb, + unsigned long action, void *hcpu) +{ + if (action == CPU_STARTING || action == CPU_STARTING_FROZEN) + armada_xp_clear_shared_l2(); + + return NOTIFY_OK; +} + +static struct notifier_block armada_xp_clear_shared_l2_notifier = { + .notifier_call = armada_xp_clear_shared_l2_notifier_func, + .priority = 100, +}; + static void __init armada_370_coherency_init(struct device_node *np) { struct resource res; + struct device_node *cpu_config_np; of_address_to_resource(np, 0, &res); coherency_phys_base = res.start; @@ -100,6 +141,23 @@ static void __init armada_370_coherency_init(struct device_node *np) sync_cache_w(&coherency_phys_base); coherency_base = of_iomap(np, 0); coherency_cpu_base = of_iomap(np, 1); + + cpu_config_np = of_find_compatible_node(NULL, NULL, + "marvell,armada-xp-cpu-config"); + if (!cpu_config_np) + goto exit; + + cpu_config_base = of_iomap(cpu_config_np, 0); + if (!cpu_config_base) { + of_node_put(cpu_config_np); + goto exit; + } + + of_node_put(cpu_config_np); + + register_cpu_notifier(&armada_xp_clear_shared_l2_notifier); + +exit: set_cpu_coherent(); } @@ -204,6 +262,8 @@ int set_cpu_coherent(void) pr_warn("Coherency fabric is not initialized\n"); return 1; } + + armada_xp_clear_shared_l2(); ll_add_cpu_to_smp_group(); return ll_enable_coherency(); }