[S390] hibernate: Do real CPU swap at resume time

Currently, when the physical resume CPU is not equal to the physical suspend
CPU, we swap the CPUs logically, by modifying the logical/physical CPU mapping.
This has two major drawbacks: First the change is visible from user space (e.g.
CPU sysfs files) and second it is hard to ensure that nowhere in the kernel
the physical CPU ID is stored before suspend.
To fix this, we now really swap the physical CPUs, if the resume CPU is not
the pysical suspend CPU. We restart the suspend CPU and stop the resume CPU
using SIGP restart and SIGP stop. If the suspend CPU is no longer available,
we write a message and load a disabled wait PSW.

Signed-off-by: Michael Holzheu <michael.holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 0 insertions, 36 deletions

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 6f14734abe7..b4b6396e6cf 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -1041,42 +1041,6 @@ out:
 static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show,
 			 dispatching_store);
 
-/*
- * If the resume kernel runs on another cpu than the suspended kernel,
- * we have to switch the cpu IDs in the logical map.
- */
-void smp_switch_boot_cpu_in_resume(u32 resume_phys_cpu_id,
-				   struct _lowcore *suspend_lowcore)
-{
-	int cpu, suspend_cpu_id, resume_cpu_id;
-	u32 suspend_phys_cpu_id;
-
-	suspend_phys_cpu_id = __cpu_logical_map[suspend_lowcore->cpu_nr];
-	suspend_cpu_id = suspend_lowcore->cpu_nr;
-
-	for_each_present_cpu(cpu) {
-		if (__cpu_logical_map[cpu] == resume_phys_cpu_id) {
-			resume_cpu_id = cpu;
-			goto found;
-		}
-	}
-	panic("Could not find resume cpu in logical map.\n");
-
-found:
-	printk("Resume  cpu ID: %i/%i\n", resume_phys_cpu_id, resume_cpu_id);
-	printk("Suspend cpu ID: %i/%i\n", suspend_phys_cpu_id, suspend_cpu_id);
-
-	__cpu_logical_map[resume_cpu_id] = suspend_phys_cpu_id;
-	__cpu_logical_map[suspend_cpu_id] = resume_phys_cpu_id;
-
-	lowcore_ptr[suspend_cpu_id]->cpu_addr = resume_phys_cpu_id;
-}
-
-u32 smp_get_phys_cpu_id(void)
-{
-	return __cpu_logical_map[smp_processor_id()];
-}
-
 static int __init topology_init(void)
 {
 	int cpu;