diff options
Diffstat (limited to 'arch/arm64/kernel/psci.c')
| -rw-r--r-- | arch/arm64/kernel/psci.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c index 8737484f24bb..03b82c60e6c7 100644 --- a/arch/arm64/kernel/psci.c +++ b/arch/arm64/kernel/psci.c @@ -27,6 +27,7 @@ #include <asm/acpi.h> #include <asm/compiler.h> +#include <asm/cputype.h> #include <asm/cpu_ops.h> #include <asm/errno.h> #include <asm/psci.h> @@ -43,6 +44,19 @@ struct psci_power_state { u8 affinity_level; }; +/* + * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF + * calls to its resident CPU, so we must avoid issuing those. We never migrate + * a Trusted OS even if it claims to be capable of migration -- doing so will + * require cooperation with a Trusted OS driver. + */ +static int resident_cpu = -1; + +static bool psci_tos_resident_on(int cpu) +{ + return cpu == resident_cpu; +} + struct psci_operations { int (*cpu_suspend)(struct psci_power_state state, unsigned long entry_point); @@ -172,6 +186,11 @@ static int psci_migrate_info_type(void) return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0); } +static unsigned long psci_migrate_info_up_cpu(void) +{ + return invoke_psci_fn(PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU, 0, 0, 0); +} + static int __maybe_unused cpu_psci_cpu_init_idle(unsigned int cpu) { int i, ret, count = 0; @@ -264,6 +283,46 @@ static void psci_sys_poweroff(void) invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0); } +/* + * Detect the presence of a resident Trusted OS which may cause CPU_OFF to + * return DENIED (which would be fatal). + */ +static void __init psci_init_migrate(void) +{ + unsigned long cpuid; + int type, cpu; + + type = psci_ops.migrate_info_type(); + + if (type == PSCI_0_2_TOS_MP) { + pr_info("Trusted OS migration not required\n"); + return; + } + + if (type == PSCI_RET_NOT_SUPPORTED) { + pr_info("MIGRATE_INFO_TYPE not supported.\n"); + return; + } + + if (type != PSCI_0_2_TOS_UP_MIGRATE && + type != PSCI_0_2_TOS_UP_NO_MIGRATE) { + pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type); + return; + } + + cpuid = psci_migrate_info_up_cpu(); + if (cpuid & ~MPIDR_HWID_BITMASK) { + pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n", + cpuid); + return; + } + + cpu = get_logical_index(cpuid); + resident_cpu = cpu >= 0 ? cpu : -1; + + pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid); +} + static void __init psci_0_2_set_functions(void) { pr_info("Using standard PSCI v0.2 function IDs\n"); @@ -306,6 +365,8 @@ static int __init psci_probe(void) psci_0_2_set_functions(); + psci_init_migrate(); + return 0; } @@ -452,6 +513,11 @@ static int cpu_psci_cpu_disable(unsigned int cpu) /* Fail early if we don't have CPU_OFF support */ if (!psci_ops.cpu_off) return -EOPNOTSUPP; + + /* Trusted OS will deny CPU_OFF */ + if (psci_tos_resident_on(cpu)) + return -EPERM; + return 0; } |