@@ -124,6 +124,7 @@ extern int opal_enter_rtas(struct rtas_args *args,
#define OPAL_PCI_POLL 62
#define OPAL_PCI_MSI_EOI 63
#define OPAL_PCI_GET_PHB_DIAG_DATA2 64
+#define OPAL_RETURN_CPU 69
#ifndef __ASSEMBLY__
@@ -631,6 +632,7 @@ 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);
/* Internal functions */
extern int early_init_dt_scan_opal(unsigned long node, const char *uname, int depth, void *data);
@@ -111,3 +111,4 @@ OPAL_CALL(opal_pci_next_error, OPAL_PCI_NEXT_ERROR);
OPAL_CALL(opal_pci_poll, OPAL_PCI_POLL);
OPAL_CALL(opal_pci_msi_eoi, OPAL_PCI_MSI_EOI);
OPAL_CALL(opal_pci_get_phb_diag_data2, OPAL_PCI_GET_PHB_DIAG_DATA2);
+OPAL_CALL(opal_return_cpu, OPAL_RETURN_CPU);
@@ -31,6 +31,7 @@
#include <asm/xics.h>
#include <asm/rtas.h>
#include <asm/opal.h>
+#include <asm/kexec.h>
#include "powernv.h"
@@ -147,6 +148,16 @@ 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 */
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 <benh@kernel.crashing.org> --- v2: Actually applies on top of current kernels rather than some obscure internal branch :-) 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(+)