Use SGI0 interruption and TAMP_BACKUP_MAGIC_NUMBER to synchronize the core1 boot sequence requested by core0 in psci_cpu_on(): - a initial interruption is needed in ROM code after RCC_MP_GRSTCSETR_MPUP1RST (psci_cpu_off) - the ROM code set to 0 the 2 registers + TAMP_BACKUP_BRANCH_ADDRESS + TAMP_BACKUP_MAGIC_NUMBER when magic is not egual to BOOT_API_A7_CORE0_MAGIC_NUMBER
This patch solve issue for cpu1 restart in kernel. echo 0 > /sys/devices/system/cpu/cpu1/online echo 1 > /sys/devices/system/cpu/cpu1/online
Signed-off-by: Patrick Delaunay patrick.delaunay@st.com ---
arch/arm/mach-stm32mp/psci.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-)
diff --git a/arch/arm/mach-stm32mp/psci.c b/arch/arm/mach-stm32mp/psci.c index c2dff38..139bb09 100644 --- a/arch/arm/mach-stm32mp/psci.c +++ b/arch/arm/mach-stm32mp/psci.c @@ -47,14 +47,14 @@ static u32 __secure stm32mp_get_gicd_base_address(void) return (periphbase & CBAR_MASK) + GIC_DIST_OFFSET; }
-static void __secure stm32mp_smp_kick_all_cpus(void) +static void __secure stm32mp_raise_sgi0(int cpu) { u32 gic_dist_addr;
gic_dist_addr = stm32mp_get_gicd_base_address();
- /* kick all CPUs (except this one) by writing to GICD_SGIR */ - writel(1U << 24, gic_dist_addr + GICD_SGIR); + /* ask cpu with SGI0 */ + writel((BIT(cpu) << 16), gic_dist_addr + GICD_SGIR); }
void __secure psci_arch_cpu_entry(void) @@ -62,6 +62,9 @@ void __secure psci_arch_cpu_entry(void) u32 cpu = psci_get_cpu_id();
psci_set_state(cpu, PSCI_AFFINITY_LEVEL_ON); + + /* reset magic in TAMP register */ + writel(0xFFFFFFFF, TAMP_BACKUP_MAGIC_NUMBER); }
int __secure psci_features(u32 function_id, u32 psci_fid) @@ -127,6 +130,16 @@ int __secure psci_cpu_on(u32 function_id, u32 target_cpu, u32 pc, if (psci_state[cpu] == PSCI_AFFINITY_LEVEL_ON) return ARM_PSCI_RET_ALREADY_ON;
+ /* reset magic in TAMP register */ + if (readl(TAMP_BACKUP_MAGIC_NUMBER)) + writel(0xFFFFFFFF, TAMP_BACKUP_MAGIC_NUMBER); + /* + * ROM code need a first SGI0 after core reset + * core is ready when magic is set to 0 in ROM code + */ + while (readl(TAMP_BACKUP_MAGIC_NUMBER)) + stm32mp_raise_sgi0(cpu); + /* store target PC and context id*/ psci_save(cpu, pc, context_id);
@@ -142,7 +155,8 @@ int __secure psci_cpu_on(u32 function_id, u32 target_cpu, u32 pc, writel(BOOT_API_A7_CORE0_MAGIC_NUMBER, TAMP_BACKUP_MAGIC_NUMBER);
- stm32mp_smp_kick_all_cpus(); + /* Generate an IT to start the core */ + stm32mp_raise_sgi0(cpu);
return ARM_PSCI_RET_SUCCESS; }