ARM: suspend: use hash of cpu_logical_map value to index into save array
Currently we hash the MPIDR of the CPU being suspended to determine which
entry in the sleep_save_sp array to use. In some situations, such as when
we want to resume on another physical CPU, the MPIDR of another CPU should
be used instead.
So let's use the value of cpu_logical_map(smp_processor_id()) in place
of the MPIDR in the suspend path. This will result in the same index
being used as with the previous code unless the caller has modified
cpu_logical_map() beforehand with the MPIDR of the physical CPU the
suspending logical CPU will resume on.
Consequently, if doing a physical CPU migration, cpu_logical_map() must
be updated appropriately somewhere between cpu_pm_enter() and
cpu_suspend().
The register allocation in __cpu_suspend is reworked in order to better
accommodate the additional argument.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
diff --git a/arch/arm/kernel/suspend.c b/arch/arm/kernel/suspend.c
index 41cf3cb..2835d35 100644
--- a/arch/arm/kernel/suspend.c
+++ b/arch/arm/kernel/suspend.c
@@ -10,7 +10,7 @@
#include <asm/suspend.h>
#include <asm/tlbflush.h>
-extern int __cpu_suspend(unsigned long, int (*)(unsigned long));
+extern int __cpu_suspend(unsigned long, int (*)(unsigned long), u32 cpuid);
extern void cpu_resume_mmu(void);
#ifdef CONFIG_MMU
@@ -21,6 +21,7 @@
int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
{
struct mm_struct *mm = current->active_mm;
+ u32 __mpidr = cpu_logical_map(smp_processor_id());
int ret;
if (!idmap_pgd)
@@ -32,7 +33,7 @@
* resume (indicated by a zero return code), we need to switch
* back to the correct page tables.
*/
- ret = __cpu_suspend(arg, fn);
+ ret = __cpu_suspend(arg, fn, __mpidr);
if (ret == 0) {
cpu_switch_mm(mm->pgd, mm);
local_flush_bp_all();
@@ -44,7 +45,8 @@
#else
int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
{
- return __cpu_suspend(arg, fn);
+ u32 __mpidr = cpu_logical_map(smp_processor_id());
+ return __cpu_suspend(arg, fn, __mpidr);
}
#define idmap_pgd NULL
#endif
