From patchwork Sat Jul 11 16:08:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Glass X-Patchwork-Id: 241367 List-Id: U-Boot discussion From: sjg at chromium.org (Simon Glass) Date: Sat, 11 Jul 2020 10:08:19 -0600 Subject: [PATCH v5 14/25] x86: mp: Park CPUs before running the OS Message-ID: <20200711160830.3451794-13-sjg@chromium.org> With the new MP features the CPUs are no-longer parked when the OS is run. Fix this by calling a special function to park them, just before the OS is started. Signed-off-by: Simon Glass Reviewed-by: Wolfgang Wallner --- Changes in v5: - Drop timing in mp_park_aps() Changes in v3: - Update the comment for mp_park_aps() arch/x86/cpu/cpu.c | 5 +++++ arch/x86/cpu/mp_init.c | 16 ++++++++++++++++ arch/x86/include/asm/mp.h | 17 +++++++++++++++++ 3 files changed, 38 insertions(+) diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c index d0720fb7fb..baa7dae172 100644 --- a/arch/x86/cpu/cpu.c +++ b/arch/x86/cpu/cpu.c @@ -66,6 +66,11 @@ static const char *const x86_vendor_name[] = { int __weak x86_cleanup_before_linux(void) { + int ret; + + ret = mp_park_aps(); + if (ret) + return log_msg_ret("park", ret); bootstage_stash((void *)CONFIG_BOOTSTAGE_STASH_ADDR, CONFIG_BOOTSTAGE_STASH_SIZE); diff --git a/arch/x86/cpu/mp_init.c b/arch/x86/cpu/mp_init.c index dd6d6bfab7..427ec8fc23 100644 --- a/arch/x86/cpu/mp_init.c +++ b/arch/x86/cpu/mp_init.c @@ -668,6 +668,22 @@ int mp_run_on_cpus(int cpu_select, mp_run_func func, void *arg) return 0; } +static void park_this_cpu(void *unused) +{ + stop_this_cpu(); +} + +int mp_park_aps(void) +{ + int ret; + + ret = mp_run_on_cpus(MP_SELECT_APS, park_this_cpu, NULL); + if (ret) + return log_ret(ret); + + return 0; +} + int mp_init(void) { int num_aps, num_cpus; diff --git a/arch/x86/include/asm/mp.h b/arch/x86/include/asm/mp.h index eb49e690f2..f9d6c8e6bf 100644 --- a/arch/x86/include/asm/mp.h +++ b/arch/x86/include/asm/mp.h @@ -109,6 +109,15 @@ typedef void (*mp_run_func)(void *arg); * @return 0 on success, -ve on error */ int mp_run_on_cpus(int cpu_select, mp_run_func func, void *arg); + +/** + * mp_park_aps() - Park the APs ready for the OS + * + * This halts all CPUs except the main one, ready for the OS to use them + * + * @return 0 if OK, -ve on error + */ +int mp_park_aps(void); #else static inline int mp_run_on_cpus(int cpu_select, mp_run_func func, void *arg) { @@ -117,6 +126,14 @@ static inline int mp_run_on_cpus(int cpu_select, mp_run_func func, void *arg) return 0; } + +static inline int mp_park_aps(void) +{ + /* No APs to park */ + + return 0; +} + #endif #endif /* _X86_MP_H_ */