These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / arch / arm64 / kernel / suspend.c

diff --git a/kernel/arch/arm64/kernel/suspend.c b/kernel/arch/arm64/kernel/suspend.c
index d7daf45..1095aa4 100644 (file)
--- a/kernel/arch/arm64/kernel/suspend.c
+++ b/kernel/arch/arm64/kernel/suspend.c
@@ -1,3 +1,4 @@
+#include <linux/ftrace.h>
 #include <linux/percpu.h>
 #include <linux/slab.h>
 #include <asm/cacheflush.h>
@@ -41,7 +42,7 @@ void notrace __cpu_suspend_save(struct cpu_suspend_ctx *ptr,
  * time the notifier runs debug exceptions might have been enabled already,
  * with HW breakpoints registers content still in an unknown state.
  */
-void (*hw_breakpoint_restore)(void *);
+static void (*hw_breakpoint_restore)(void *);
 void __init cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *))
 {
        /* Prevent multiple restore hook initializations */
@@ -51,13 +52,13 @@ void __init cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *))
 }
 
 /*
- * __cpu_suspend
+ * cpu_suspend
  *
  * arg: argument to pass to the finisher function
  * fn: finisher function pointer
  *
  */
-int __cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
+int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
 {
        struct mm_struct *mm = current->active_mm;
        int ret;
@@ -70,6 +71,13 @@ int __cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
         */
        local_dbg_save(flags);
 
+       /*
+        * Function graph tracer state gets incosistent when the kernel
+        * calls functions that never return (aka suspend finishers) hence
+        * disable graph tracing during their execution.
+        */
+       pause_graph_tracing();
+
        /*
         * mm context saved on the stack, it will be restored when
         * the cpu comes out of reset through the identity mapped
@@ -80,17 +88,21 @@ int __cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
        if (ret == 0) {
                /*
                 * We are resuming from reset with TTBR0_EL1 set to the
-                * idmap to enable the MMU; restore the active_mm mappings in
-                * TTBR0_EL1 unless the active_mm == &init_mm, in which case
-                * the thread entered __cpu_suspend with TTBR0_EL1 set to
-                * reserved TTBR0 page tables and should be restored as such.
+                * idmap to enable the MMU; set the TTBR0 to the reserved
+                * page tables to prevent speculative TLB allocations, flush
+                * the local tlb and set the default tcr_el1.t0sz so that
+                * the TTBR0 address space set-up is properly restored.
+                * If the current active_mm != &init_mm we entered cpu_suspend
+                * with mappings in TTBR0 that must be restored, so we switch
+                * them back to complete the address space configuration
+                * restoration before returning.
                 */
-               if (mm == &init_mm)
-                       cpu_set_reserved_ttbr0();
-               else
-                       cpu_switch_mm(mm->pgd, mm);
+               cpu_set_reserved_ttbr0();
+               local_flush_tlb_all();
+               cpu_set_default_tcr_t0sz();
 
-               flush_tlb_all();
+               if (mm != &init_mm)
+                       cpu_switch_mm(mm->pgd, mm);
 
                /*
                 * Restore per-cpu offset before any kernel
@@ -107,6 +119,8 @@ int __cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
                        hw_breakpoint_restore(NULL);
        }
 
+       unpause_graph_tracing();
+
        /*
         * Restore pstate flags. OS lock and mdscr have been already
         * restored, so from this point onwards, debugging is fully
@@ -118,7 +132,6 @@ int __cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
 }
 
 struct sleep_save_sp sleep_save_sp;
-phys_addr_t sleep_idmap_phys;
 
 static int __init cpu_suspend_init(void)
 {
@@ -132,9 +145,7 @@ static int __init cpu_suspend_init(void)
 
        sleep_save_sp.save_ptr_stash = ctx_ptr;
        sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr);
-       sleep_idmap_phys = virt_to_phys(idmap_pg_dir);
        __flush_dcache_area(&sleep_save_sp, sizeof(struct sleep_save_sp));
-       __flush_dcache_area(&sleep_idmap_phys, sizeof(sleep_idmap_phys));
 
        return 0;
 }