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-rw-r--r--arch/arm/kernel/suspend.c122
1 files changed, 122 insertions, 0 deletions
diff --git a/arch/arm/kernel/suspend.c b/arch/arm/kernel/suspend.c
new file mode 100644
index 0000000000..c3ec3861dd
--- /dev/null
+++ b/arch/arm/kernel/suspend.c
@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/ftrace.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/mm_types.h>
+#include <linux/pgtable.h>
+
+#include <asm/bugs.h>
+#include <asm/cacheflush.h>
+#include <asm/idmap.h>
+#include <asm/page.h>
+#include <asm/smp_plat.h>
+#include <asm/suspend.h>
+#include <asm/tlbflush.h>
+
+extern int __cpu_suspend(unsigned long, int (*)(unsigned long), u32 cpuid);
+extern void cpu_resume_mmu(void);
+
+#ifdef CONFIG_MMU
+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)
+ return -EINVAL;
+
+ /*
+ * 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();
+
+ /*
+ * Provide a temporary page table with an identity mapping for
+ * the MMU-enable code, required for resuming. On successful
+ * resume (indicated by a zero return code), we need to switch
+ * back to the correct page tables.
+ */
+ ret = __cpu_suspend(arg, fn, __mpidr);
+
+ unpause_graph_tracing();
+
+ if (ret == 0) {
+ cpu_switch_mm(mm->pgd, mm);
+ local_flush_bp_all();
+ local_flush_tlb_all();
+ check_other_bugs();
+ }
+
+ return ret;
+}
+#else
+int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
+{
+ u32 __mpidr = cpu_logical_map(smp_processor_id());
+ int ret;
+
+ pause_graph_tracing();
+ ret = __cpu_suspend(arg, fn, __mpidr);
+ unpause_graph_tracing();
+
+ return ret;
+}
+#define idmap_pgd NULL
+#endif
+
+/*
+ * This is called by __cpu_suspend() to save the state, and do whatever
+ * flushing is required to ensure that when the CPU goes to sleep we have
+ * the necessary data available when the caches are not searched.
+ */
+void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr)
+{
+ u32 *ctx = ptr;
+
+ *save_ptr = virt_to_phys(ptr);
+
+ /* This must correspond to the LDM in cpu_resume() assembly */
+ *ptr++ = virt_to_phys(idmap_pgd);
+ *ptr++ = sp;
+ *ptr++ = virt_to_phys(cpu_do_resume);
+
+ cpu_do_suspend(ptr);
+
+ flush_cache_louis();
+
+ /*
+ * flush_cache_louis does not guarantee that
+ * save_ptr and ptr are cleaned to main memory,
+ * just up to the Level of Unification Inner Shareable.
+ * Since the context pointer and context itself
+ * are to be retrieved with the MMU off that
+ * data must be cleaned from all cache levels
+ * to main memory using "area" cache primitives.
+ */
+ __cpuc_flush_dcache_area(ctx, ptrsz);
+ __cpuc_flush_dcache_area(save_ptr, sizeof(*save_ptr));
+
+ outer_clean_range(*save_ptr, *save_ptr + ptrsz);
+ outer_clean_range(virt_to_phys(save_ptr),
+ virt_to_phys(save_ptr) + sizeof(*save_ptr));
+}
+
+extern struct sleep_save_sp sleep_save_sp;
+
+static int cpu_suspend_alloc_sp(void)
+{
+ void *ctx_ptr;
+ /* ctx_ptr is an array of physical addresses */
+ ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(u32), GFP_KERNEL);
+
+ if (WARN_ON(!ctx_ptr))
+ return -ENOMEM;
+ sleep_save_sp.save_ptr_stash = ctx_ptr;
+ sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr);
+ sync_cache_w(&sleep_save_sp);
+ return 0;
+}
+early_initcall(cpu_suspend_alloc_sp);