diff options
| -rw-r--r-- | src/drivers/intel/fsp2_0/ppi/mp_service_ppi.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/src/drivers/intel/fsp2_0/ppi/mp_service_ppi.c b/src/drivers/intel/fsp2_0/ppi/mp_service_ppi.c index 3f1e83d541..5b537a9531 100644 --- a/src/drivers/intel/fsp2_0/ppi/mp_service_ppi.c +++ b/src/drivers/intel/fsp2_0/ppi/mp_service_ppi.c @@ -94,9 +94,21 @@ efi_return_status_t mp_startup_all_cpus(efi_ap_procedure procedure, /* Run on BSP */ procedure(argument); - /* Run on APs */ - if (mp_run_on_aps((void *)procedure, argument, - MP_RUN_ON_ALL_CPUS, timeout_usec) != CB_SUCCESS) { + /* + * Run on APs Serially + * + * FIXME: As per MP service specification, EDK2 is allowed to specify the mode + * in which a 'func' routine should be executed on APs (i.e. execute serially + * or concurrently). + * + * MP service API `StartupAllCPUs` doesn't specify such requirement. + * Hence, running the `CpuCacheInfoCollectCoreAndCacheData` + * (UefiCpuPkg/Library/CpuCacheInfoLib/CpuCacheInfoLib.c#194) + * simultaneously on APs results in a coherency issue (hang while executing `func`) + * due to lack of acquiring a spin lock while accessing common data structure in + * multiprocessor environment. + */ + if (mp_run_on_all_aps((void *)procedure, argument, timeout_usec, false)) { printk(BIOS_DEBUG, "%s: Exit with Failure\n", __func__); return FSP_NOT_STARTED; } |