diff options
Diffstat (limited to 'arch/arm64/kernel/idreg-override.c')
| -rw-r--r-- | arch/arm64/kernel/idreg-override.c | 69 |
1 files changed, 48 insertions, 21 deletions
diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c index dffb16682330..e628c8ce1ffe 100644 --- a/arch/arm64/kernel/idreg-override.c +++ b/arch/arm64/kernel/idreg-override.c @@ -25,14 +25,26 @@ struct ftr_set_desc { struct { char name[FTR_DESC_FIELD_LEN]; u8 shift; + bool (*filter)(u64 val); } fields[]; }; +static bool __init mmfr1_vh_filter(u64 val) +{ + /* + * If we ever reach this point while running VHE, we're + * guaranteed to be on one of these funky, VHE-stuck CPUs. If + * the user was trying to force nVHE on us, proceed with + * attitude adjustment. + */ + return !(is_kernel_in_hyp_mode() && val == 0); +} + static const struct ftr_set_desc mmfr1 __initconst = { .name = "id_aa64mmfr1", .override = &id_aa64mmfr1_override, .fields = { - { "vh", ID_AA64MMFR1_VHE_SHIFT }, + { "vh", ID_AA64MMFR1_VHE_SHIFT, mmfr1_vh_filter }, {} }, }; @@ -124,6 +136,18 @@ static void __init match_options(const char *cmdline) if (find_field(cmdline, regs[i], f, &v)) continue; + /* + * If an override gets filtered out, advertise + * it by setting the value to 0xf, but + * clearing the mask... Yes, this is fragile. + */ + if (regs[i]->fields[f].filter && + !regs[i]->fields[f].filter(v)) { + regs[i]->override->val |= mask; + regs[i]->override->mask &= ~mask; + continue; + } + regs[i]->override->val &= ~mask; regs[i]->override->val |= (v << shift) & mask; regs[i]->override->mask |= mask; @@ -163,33 +187,36 @@ static __init void __parse_cmdline(const char *cmdline, bool parse_aliases) } while (1); } -static __init void parse_cmdline(void) +static __init const u8 *get_bootargs_cmdline(void) { - if (!IS_ENABLED(CONFIG_CMDLINE_FORCE)) { - const u8 *prop; - void *fdt; - int node; + const u8 *prop; + void *fdt; + int node; - fdt = get_early_fdt_ptr(); - if (!fdt) - goto out; + fdt = get_early_fdt_ptr(); + if (!fdt) + return NULL; - node = fdt_path_offset(fdt, "/chosen"); - if (node < 0) - goto out; + node = fdt_path_offset(fdt, "/chosen"); + if (node < 0) + return NULL; - prop = fdt_getprop(fdt, node, "bootargs", NULL); - if (!prop) - goto out; + prop = fdt_getprop(fdt, node, "bootargs", NULL); + if (!prop) + return NULL; - __parse_cmdline(prop, true); + return strlen(prop) ? prop : NULL; +} - if (!IS_ENABLED(CONFIG_CMDLINE_EXTEND)) - return; - } +static __init void parse_cmdline(void) +{ + const u8 *prop = get_bootargs_cmdline(); + + if (IS_ENABLED(CONFIG_CMDLINE_FORCE) || !prop) + __parse_cmdline(CONFIG_CMDLINE, true); -out: - __parse_cmdline(CONFIG_CMDLINE, true); + if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && prop) + __parse_cmdline(prop, true); } /* Keep checkers quiet */ |