From 13906db670a128864714c30c244b866dce119494 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 21 Aug 2013 13:03:20 +1000 Subject: [PATCH] powerpc/powernv: Return secondary CPUs to firmware on kexec With OPAL v3 we can return secondary CPUs to firmware on kexec. This allows firmware to do various cleanups making things generally more reliable, and will enable the "new" kernel to call OPAL to perform some reconfiguration tasks early on that can only be done while all the CPUs are in firmware. Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/opal.h | 2 ++ arch/powerpc/platforms/powernv/opal-wrappers.S | 1 + arch/powerpc/platforms/powernv/setup.c | 11 +++++++++++ 3 files changed, 14 insertions(+) diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h index 48ad678..c5cd728 100644 --- a/arch/powerpc/include/asm/opal.h +++ b/arch/powerpc/include/asm/opal.h @@ -128,6 +128,7 @@ extern int opal_enter_rtas(struct rtas_args *args, #define OPAL_XSCOM_WRITE 66 #define OPAL_LPC_READ 67 #define OPAL_LPC_WRITE 68 +#define OPAL_RETURN_CPU 69 #ifndef __ASSEMBLY__ @@ -646,6 +647,7 @@ int64_t opal_set_system_attention_led(uint8_t led_action); int64_t opal_pci_next_error(uint64_t phb_id, uint64_t *first_frozen_pe, uint16_t *pci_error_type, uint16_t *severity); int64_t opal_pci_poll(uint64_t phb_id); +int64_t opal_return_cpu(void); int64_t opal_xscom_read(uint32_t gcid, uint32_t pcb_addr, uint64_t *val); int64_t opal_xscom_write(uint32_t gcid, uint32_t pcb_addr, uint64_t val); diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S index 42c06fb..8f38445 100644 --- a/arch/powerpc/platforms/powernv/opal-wrappers.S +++ b/arch/powerpc/platforms/powernv/opal-wrappers.S @@ -115,3 +115,4 @@ OPAL_CALL(opal_xscom_read, OPAL_XSCOM_READ); OPAL_CALL(opal_xscom_write, OPAL_XSCOM_WRITE); OPAL_CALL(opal_lpc_read, OPAL_LPC_READ); OPAL_CALL(opal_lpc_write, OPAL_LPC_WRITE); +OPAL_CALL(opal_return_cpu, OPAL_RETURN_CPU); diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c index 4ddb339..e239dcf 100644 --- a/arch/powerpc/platforms/powernv/setup.c +++ b/arch/powerpc/platforms/powernv/setup.c @@ -31,6 +31,7 @@ #include #include #include +#include #include "powernv.h" @@ -153,6 +154,16 @@ static void pnv_shutdown(void) static void pnv_kexec_cpu_down(int crash_shutdown, int secondary) { xics_kexec_teardown_cpu(secondary); + + /* Return secondary CPUs to firmware on OPAL v3 */ + if (firmware_has_feature(FW_FEATURE_OPALv3) && secondary) { + mb(); + get_paca()->kexec_state = KEXEC_STATE_REAL_MODE; + mb(); + + /* Return the CPU to OPAL */ + opal_return_cpu(); + } } #endif /* CONFIG_KEXEC */ -- 2.7.4