mm: hugetlb: fix hugepage memory leak caused by wrong reserve count
[linux/fpc-iii.git] / arch / arm64 / kernel / suspend.c
blob1095aa483a1c28e5387b23895c14d7a1746268a3
1 #include <linux/ftrace.h>
2 #include <linux/percpu.h>
3 #include <linux/slab.h>
4 #include <asm/cacheflush.h>
5 #include <asm/debug-monitors.h>
6 #include <asm/pgtable.h>
7 #include <asm/memory.h>
8 #include <asm/mmu_context.h>
9 #include <asm/smp_plat.h>
10 #include <asm/suspend.h>
11 #include <asm/tlbflush.h>
13 extern int __cpu_suspend_enter(unsigned long arg, int (*fn)(unsigned long));
15 * This is called by __cpu_suspend_enter() to save the state, and do whatever
16 * flushing is required to ensure that when the CPU goes to sleep we have
17 * the necessary data available when the caches are not searched.
19 * ptr: CPU context virtual address
20 * save_ptr: address of the location where the context physical address
21 * must be saved
23 void notrace __cpu_suspend_save(struct cpu_suspend_ctx *ptr,
24 phys_addr_t *save_ptr)
26 *save_ptr = virt_to_phys(ptr);
28 cpu_do_suspend(ptr);
30 * Only flush the context that must be retrieved with the MMU
31 * off. VA primitives ensure the flush is applied to all
32 * cache levels so context is pushed to DRAM.
34 __flush_dcache_area(ptr, sizeof(*ptr));
35 __flush_dcache_area(save_ptr, sizeof(*save_ptr));
39 * This hook is provided so that cpu_suspend code can restore HW
40 * breakpoints as early as possible in the resume path, before reenabling
41 * debug exceptions. Code cannot be run from a CPU PM notifier since by the
42 * time the notifier runs debug exceptions might have been enabled already,
43 * with HW breakpoints registers content still in an unknown state.
45 static void (*hw_breakpoint_restore)(void *);
46 void __init cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *))
48 /* Prevent multiple restore hook initializations */
49 if (WARN_ON(hw_breakpoint_restore))
50 return;
51 hw_breakpoint_restore = hw_bp_restore;
55 * cpu_suspend
57 * arg: argument to pass to the finisher function
58 * fn: finisher function pointer
61 int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
63 struct mm_struct *mm = current->active_mm;
64 int ret;
65 unsigned long flags;
68 * From this point debug exceptions are disabled to prevent
69 * updates to mdscr register (saved and restored along with
70 * general purpose registers) from kernel debuggers.
72 local_dbg_save(flags);
75 * Function graph tracer state gets incosistent when the kernel
76 * calls functions that never return (aka suspend finishers) hence
77 * disable graph tracing during their execution.
79 pause_graph_tracing();
82 * mm context saved on the stack, it will be restored when
83 * the cpu comes out of reset through the identity mapped
84 * page tables, so that the thread address space is properly
85 * set-up on function return.
87 ret = __cpu_suspend_enter(arg, fn);
88 if (ret == 0) {
90 * We are resuming from reset with TTBR0_EL1 set to the
91 * idmap to enable the MMU; set the TTBR0 to the reserved
92 * page tables to prevent speculative TLB allocations, flush
93 * the local tlb and set the default tcr_el1.t0sz so that
94 * the TTBR0 address space set-up is properly restored.
95 * If the current active_mm != &init_mm we entered cpu_suspend
96 * with mappings in TTBR0 that must be restored, so we switch
97 * them back to complete the address space configuration
98 * restoration before returning.
100 cpu_set_reserved_ttbr0();
101 local_flush_tlb_all();
102 cpu_set_default_tcr_t0sz();
104 if (mm != &init_mm)
105 cpu_switch_mm(mm->pgd, mm);
108 * Restore per-cpu offset before any kernel
109 * subsystem relying on it has a chance to run.
111 set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
114 * Restore HW breakpoint registers to sane values
115 * before debug exceptions are possibly reenabled
116 * through local_dbg_restore.
118 if (hw_breakpoint_restore)
119 hw_breakpoint_restore(NULL);
122 unpause_graph_tracing();
125 * Restore pstate flags. OS lock and mdscr have been already
126 * restored, so from this point onwards, debugging is fully
127 * renabled if it was enabled when core started shutdown.
129 local_dbg_restore(flags);
131 return ret;
134 struct sleep_save_sp sleep_save_sp;
136 static int __init cpu_suspend_init(void)
138 void *ctx_ptr;
140 /* ctx_ptr is an array of physical addresses */
141 ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(phys_addr_t), GFP_KERNEL);
143 if (WARN_ON(!ctx_ptr))
144 return -ENOMEM;
146 sleep_save_sp.save_ptr_stash = ctx_ptr;
147 sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr);
148 __flush_dcache_area(&sleep_save_sp, sizeof(struct sleep_save_sp));
150 return 0;
152 early_initcall(cpu_suspend_init);