diff options
Diffstat (limited to 'arch/powerpc/kernel/dt_cpu_ftrs.c')
| -rw-r--r-- | arch/powerpc/kernel/dt_cpu_ftrs.c | 58 |
1 files changed, 48 insertions, 10 deletions
diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c b/arch/powerpc/kernel/dt_cpu_ftrs.c index fcc7588a96d6..4c7656dc4e04 100644 --- a/arch/powerpc/kernel/dt_cpu_ftrs.c +++ b/arch/powerpc/kernel/dt_cpu_ftrs.c @@ -8,6 +8,7 @@ #include <linux/export.h> #include <linux/init.h> #include <linux/jump_label.h> +#include <linux/libfdt.h> #include <linux/memblock.h> #include <linux/printk.h> #include <linux/sched.h> @@ -642,7 +643,6 @@ static struct dt_cpu_feature_match __initdata {"processor-control-facility", feat_enable_dbell, CPU_FTR_DBELL}, {"processor-control-facility-v3", feat_enable_dbell, CPU_FTR_DBELL}, {"processor-utilization-of-resources-register", feat_enable_purr, 0}, - {"subcore", feat_enable, CPU_FTR_SUBCORE}, {"no-execute", feat_enable, 0}, {"strong-access-ordering", feat_enable, CPU_FTR_SAO}, {"cache-inhibited-large-page", feat_enable_large_ci, 0}, @@ -671,12 +671,24 @@ static struct dt_cpu_feature_match __initdata {"wait-v3", feat_enable, 0}, }; -/* XXX: how to configure this? Default + boot time? */ -#ifdef CONFIG_PPC_CPUFEATURES_ENABLE_UNKNOWN -#define CPU_FEATURE_ENABLE_UNKNOWN 1 -#else -#define CPU_FEATURE_ENABLE_UNKNOWN 0 -#endif +static bool __initdata using_dt_cpu_ftrs; +static bool __initdata enable_unknown = true; + +static int __init dt_cpu_ftrs_parse(char *str) +{ + if (!str) + return 0; + + if (!strcmp(str, "off")) + using_dt_cpu_ftrs = false; + else if (!strcmp(str, "known")) + enable_unknown = false; + else + return 1; + + return 0; +} +early_param("dt_cpu_ftrs", dt_cpu_ftrs_parse); static void __init cpufeatures_setup_start(u32 isa) { @@ -707,7 +719,7 @@ static bool __init cpufeatures_process_feature(struct dt_cpu_feature *f) } } - if (!known && CPU_FEATURE_ENABLE_UNKNOWN) { + if (!known && enable_unknown) { if (!feat_try_enable_unknown(f)) { pr_info("not enabling: %s (unknown and unsupported by kernel)\n", f->name); @@ -756,6 +768,26 @@ static void __init cpufeatures_setup_finished(void) cur_cpu_spec->cpu_features, cur_cpu_spec->mmu_features); } +static int __init disabled_on_cmdline(void) +{ + unsigned long root, chosen; + const char *p; + + root = of_get_flat_dt_root(); + chosen = of_get_flat_dt_subnode_by_name(root, "chosen"); + if (chosen == -FDT_ERR_NOTFOUND) + return false; + + p = of_get_flat_dt_prop(chosen, "bootargs", NULL); + if (!p) + return false; + + if (strstr(p, "dt_cpu_ftrs=off")) + return true; + + return false; +} + static int __init fdt_find_cpu_features(unsigned long node, const char *uname, int depth, void *data) { @@ -766,8 +798,6 @@ static int __init fdt_find_cpu_features(unsigned long node, const char *uname, return 0; } -static bool __initdata using_dt_cpu_ftrs = false; - bool __init dt_cpu_ftrs_in_use(void) { return using_dt_cpu_ftrs; @@ -775,6 +805,8 @@ bool __init dt_cpu_ftrs_in_use(void) bool __init dt_cpu_ftrs_init(void *fdt) { + using_dt_cpu_ftrs = false; + /* Setup and verify the FDT, if it fails we just bail */ if (!early_init_dt_verify(fdt)) return false; @@ -782,6 +814,9 @@ bool __init dt_cpu_ftrs_init(void *fdt) if (!of_scan_flat_dt(fdt_find_cpu_features, NULL)) return false; + if (disabled_on_cmdline()) + return false; + cpufeatures_setup_cpu(); using_dt_cpu_ftrs = true; @@ -1027,5 +1062,8 @@ static int __init dt_cpu_ftrs_scan_callback(unsigned long node, const char void __init dt_cpu_ftrs_scan(void) { + if (!using_dt_cpu_ftrs) + return; + of_scan_flat_dt(dt_cpu_ftrs_scan_callback, NULL); } |