diff options
Diffstat (limited to 'drivers/firmware/efi/runtime-wrappers.c')
| -rw-r--r-- | drivers/firmware/efi/runtime-wrappers.c | 113 |
1 files changed, 39 insertions, 74 deletions
diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c index 228bbf910461..de6953039af6 100644 --- a/drivers/firmware/efi/runtime-wrappers.c +++ b/drivers/firmware/efi/runtime-wrappers.c @@ -61,63 +61,23 @@ */ static DEFINE_SPINLOCK(efi_runtime_lock); -/* - * Some runtime services calls can be reentrant under NMI, even if the table - * above says they are not. (source: UEFI Specification v2.4A) - * - * Table 32. Functions that may be called after Machine Check, INIT and NMI - * +----------------------------+------------------------------------------+ - * | Function | Called after Machine Check, INIT and NMI | - * +----------------------------+------------------------------------------+ - * | GetTime() | Yes, even if previously busy. | - * | GetVariable() | Yes, even if previously busy | - * | GetNextVariableName() | Yes, even if previously busy | - * | QueryVariableInfo() | Yes, even if previously busy | - * | SetVariable() | Yes, even if previously busy | - * | UpdateCapsule() | Yes, even if previously busy | - * | QueryCapsuleCapabilities() | Yes, even if previously busy | - * | ResetSystem() | Yes, even if previously busy | - * +----------------------------+------------------------------------------+ - * - * In order to prevent deadlocks under NMI, the wrappers for these functions - * may only grab the efi_runtime_lock or rtc_lock spinlocks if !efi_in_nmi(). - * However, not all of the services listed are reachable through NMI code paths, - * so the the special handling as suggested by the UEFI spec is only implemented - * for QueryVariableInfo() and SetVariable(), as these can be reached in NMI - * context through efi_pstore_write(). - */ - -/* - * As per commit ef68c8f87ed1 ("x86: Serialize EFI time accesses on rtc_lock"), - * the EFI specification requires that callers of the time related runtime - * functions serialize with other CMOS accesses in the kernel, as the EFI time - * functions may choose to also use the legacy CMOS RTC. - */ -__weak DEFINE_SPINLOCK(rtc_lock); - static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc) { - unsigned long flags; efi_status_t status; - spin_lock_irqsave(&rtc_lock, flags); spin_lock(&efi_runtime_lock); status = efi_call_virt(get_time, tm, tc); spin_unlock(&efi_runtime_lock); - spin_unlock_irqrestore(&rtc_lock, flags); return status; } static efi_status_t virt_efi_set_time(efi_time_t *tm) { - unsigned long flags; efi_status_t status; - spin_lock_irqsave(&rtc_lock, flags); spin_lock(&efi_runtime_lock); status = efi_call_virt(set_time, tm); spin_unlock(&efi_runtime_lock); - spin_unlock_irqrestore(&rtc_lock, flags); return status; } @@ -125,27 +85,21 @@ static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending, efi_time_t *tm) { - unsigned long flags; efi_status_t status; - spin_lock_irqsave(&rtc_lock, flags); spin_lock(&efi_runtime_lock); status = efi_call_virt(get_wakeup_time, enabled, pending, tm); spin_unlock(&efi_runtime_lock); - spin_unlock_irqrestore(&rtc_lock, flags); return status; } static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm) { - unsigned long flags; efi_status_t status; - spin_lock_irqsave(&rtc_lock, flags); spin_lock(&efi_runtime_lock); status = efi_call_virt(set_wakeup_time, enabled, tm); spin_unlock(&efi_runtime_lock); - spin_unlock_irqrestore(&rtc_lock, flags); return status; } @@ -155,13 +109,12 @@ static efi_status_t virt_efi_get_variable(efi_char16_t *name, unsigned long *data_size, void *data) { - unsigned long flags; efi_status_t status; - spin_lock_irqsave(&efi_runtime_lock, flags); + spin_lock(&efi_runtime_lock); status = efi_call_virt(get_variable, name, vendor, attr, data_size, data); - spin_unlock_irqrestore(&efi_runtime_lock, flags); + spin_unlock(&efi_runtime_lock); return status; } @@ -169,12 +122,11 @@ static efi_status_t virt_efi_get_next_variable(unsigned long *name_size, efi_char16_t *name, efi_guid_t *vendor) { - unsigned long flags; efi_status_t status; - spin_lock_irqsave(&efi_runtime_lock, flags); + spin_lock(&efi_runtime_lock); status = efi_call_virt(get_next_variable, name_size, name, vendor); - spin_unlock_irqrestore(&efi_runtime_lock, flags); + spin_unlock(&efi_runtime_lock); return status; } @@ -184,13 +136,12 @@ static efi_status_t virt_efi_set_variable(efi_char16_t *name, unsigned long data_size, void *data) { - unsigned long flags; efi_status_t status; - spin_lock_irqsave(&efi_runtime_lock, flags); + spin_lock(&efi_runtime_lock); status = efi_call_virt(set_variable, name, vendor, attr, data_size, data); - spin_unlock_irqrestore(&efi_runtime_lock, flags); + spin_unlock(&efi_runtime_lock); return status; } @@ -199,15 +150,14 @@ virt_efi_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor, u32 attr, unsigned long data_size, void *data) { - unsigned long flags; efi_status_t status; - if (!spin_trylock_irqsave(&efi_runtime_lock, flags)) + if (!spin_trylock(&efi_runtime_lock)) return EFI_NOT_READY; status = efi_call_virt(set_variable, name, vendor, attr, data_size, data); - spin_unlock_irqrestore(&efi_runtime_lock, flags); + spin_unlock(&efi_runtime_lock); return status; } @@ -217,27 +167,45 @@ static efi_status_t virt_efi_query_variable_info(u32 attr, u64 *remaining_space, u64 *max_variable_size) { - unsigned long flags; efi_status_t status; if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION) return EFI_UNSUPPORTED; - spin_lock_irqsave(&efi_runtime_lock, flags); + spin_lock(&efi_runtime_lock); status = efi_call_virt(query_variable_info, attr, storage_space, remaining_space, max_variable_size); - spin_unlock_irqrestore(&efi_runtime_lock, flags); + spin_unlock(&efi_runtime_lock); + return status; +} + +static efi_status_t +virt_efi_query_variable_info_nonblocking(u32 attr, + u64 *storage_space, + u64 *remaining_space, + u64 *max_variable_size) +{ + efi_status_t status; + + if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION) + return EFI_UNSUPPORTED; + + if (!spin_trylock(&efi_runtime_lock)) + return EFI_NOT_READY; + + status = efi_call_virt(query_variable_info, attr, storage_space, + remaining_space, max_variable_size); + spin_unlock(&efi_runtime_lock); return status; } static efi_status_t virt_efi_get_next_high_mono_count(u32 *count) { - unsigned long flags; efi_status_t status; - spin_lock_irqsave(&efi_runtime_lock, flags); + spin_lock(&efi_runtime_lock); status = efi_call_virt(get_next_high_mono_count, count); - spin_unlock_irqrestore(&efi_runtime_lock, flags); + spin_unlock(&efi_runtime_lock); return status; } @@ -246,26 +214,23 @@ static void virt_efi_reset_system(int reset_type, unsigned long data_size, efi_char16_t *data) { - unsigned long flags; - - spin_lock_irqsave(&efi_runtime_lock, flags); + spin_lock(&efi_runtime_lock); __efi_call_virt(reset_system, reset_type, status, data_size, data); - spin_unlock_irqrestore(&efi_runtime_lock, flags); + spin_unlock(&efi_runtime_lock); } static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules, unsigned long count, unsigned long sg_list) { - unsigned long flags; efi_status_t status; if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION) return EFI_UNSUPPORTED; - spin_lock_irqsave(&efi_runtime_lock, flags); + spin_lock(&efi_runtime_lock); status = efi_call_virt(update_capsule, capsules, count, sg_list); - spin_unlock_irqrestore(&efi_runtime_lock, flags); + spin_unlock(&efi_runtime_lock); return status; } @@ -274,16 +239,15 @@ static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules, u64 *max_size, int *reset_type) { - unsigned long flags; efi_status_t status; if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION) return EFI_UNSUPPORTED; - spin_lock_irqsave(&efi_runtime_lock, flags); + spin_lock(&efi_runtime_lock); status = efi_call_virt(query_capsule_caps, capsules, count, max_size, reset_type); - spin_unlock_irqrestore(&efi_runtime_lock, flags); + spin_unlock(&efi_runtime_lock); return status; } @@ -300,6 +264,7 @@ void efi_native_runtime_setup(void) efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count; efi.reset_system = virt_efi_reset_system; efi.query_variable_info = virt_efi_query_variable_info; + efi.query_variable_info_nonblocking = virt_efi_query_variable_info_nonblocking; efi.update_capsule = virt_efi_update_capsule; efi.query_capsule_caps = virt_efi_query_capsule_caps; } |