#include <linux/ftrace.h>
#include <linux/percpu.h>
#include <linux/slab.h>
+#include <asm/alternative.h>
#include <asm/cacheflush.h>
+#include <asm/cpufeature.h>
#include <asm/debug-monitors.h>
#include <asm/pgtable.h>
#include <asm/memory.h>
#include <asm/suspend.h>
#include <asm/tlbflush.h>
-extern int __cpu_suspend_enter(unsigned long arg, int (*fn)(unsigned long));
/*
- * This is called by __cpu_suspend_enter() 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.
- *
- * ptr: CPU context virtual address
- * save_ptr: address of the location where the context physical address
- * must be saved
+ * This is allocated by cpu_suspend_init(), and used to store a pointer to
+ * the 'struct sleep_stack_data' the contains a particular CPUs state.
*/
-void notrace __cpu_suspend_save(struct cpu_suspend_ctx *ptr,
- phys_addr_t *save_ptr)
-{
- *save_ptr = virt_to_phys(ptr);
-
- cpu_do_suspend(ptr);
- /*
- * Only flush the context that must be retrieved with the MMU
- * off. VA primitives ensure the flush is applied to all
- * cache levels so context is pushed to DRAM.
- */
- __flush_dcache_area(ptr, sizeof(*ptr));
- __flush_dcache_area(save_ptr, sizeof(*save_ptr));
-}
+unsigned long *sleep_save_stash;
/*
* This hook is provided so that cpu_suspend code can restore HW
hw_breakpoint_restore = hw_bp_restore;
}
+void notrace __cpu_suspend_exit(void)
+{
+ /*
+ * We are resuming from reset with the idmap active in TTBR0_EL1.
+ * We must uninstall the idmap and restore the expected MMU
+ * state before we can possibly return to userspace.
+ */
+ cpu_uninstall_idmap();
+
+ /*
+ * Restore per-cpu offset before any kernel
+ * subsystem relying on it has a chance to run.
+ */
+ set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
+
+ /*
+ * Restore HW breakpoint registers to sane values
+ * before debug exceptions are possibly reenabled
+ * through local_dbg_restore.
+ */
+ if (hw_breakpoint_restore)
+ hw_breakpoint_restore(NULL);
+}
+
/*
* cpu_suspend
*
*/
int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
{
- struct mm_struct *mm = current->active_mm;
- int ret;
+ int ret = 0;
unsigned long flags;
+ struct sleep_stack_data state;
/*
* From this point debug exceptions are disabled to prevent
*/
pause_graph_tracing();
- /*
- * mm context saved on the stack, it will be restored when
- * the cpu comes out of reset through the identity mapped
- * page tables, so that the thread address space is properly
- * set-up on function return.
- */
- ret = __cpu_suspend_enter(arg, fn);
- if (ret == 0) {
- /*
- * We are resuming from reset with TTBR0_EL1 set to the
- * 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.
- */
- cpu_set_reserved_ttbr0();
- local_flush_tlb_all();
- cpu_set_default_tcr_t0sz();
-
- if (mm != &init_mm)
- cpu_switch_mm(mm->pgd, mm);
+ if (__cpu_suspend_enter(&state)) {
+ /* Call the suspend finisher */
+ ret = fn(arg);
/*
- * Restore per-cpu offset before any kernel
- * subsystem relying on it has a chance to run.
+ * PSTATE was not saved over suspend/resume, re-enable any
+ * detected features that might not have been set correctly.
*/
- set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
+ asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN,
+ CONFIG_ARM64_PAN));
/*
* Restore HW breakpoint registers to sane values
* before debug exceptions are possibly reenabled
* through local_dbg_restore.
*/
- if (hw_breakpoint_restore)
- hw_breakpoint_restore(NULL);
+ if (!ret)
+ ret = -EOPNOTSUPP;
+ } else {
+ __cpu_suspend_exit();
}
unpause_graph_tracing();
return ret;
}
-struct sleep_save_sp sleep_save_sp;
-
static int __init cpu_suspend_init(void)
{
- void *ctx_ptr;
-
/* ctx_ptr is an array of physical addresses */
- ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(phys_addr_t), GFP_KERNEL);
+ sleep_save_stash = kcalloc(mpidr_hash_size(), sizeof(*sleep_save_stash),
+ GFP_KERNEL);
- if (WARN_ON(!ctx_ptr))
+ if (WARN_ON(!sleep_save_stash))
return -ENOMEM;
- sleep_save_sp.save_ptr_stash = ctx_ptr;
- sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr);
- __flush_dcache_area(&sleep_save_sp, sizeof(struct sleep_save_sp));
-
return 0;
}
early_initcall(cpu_suspend_init);
projects / firefly-linux-kernel-4.4.55.git / blobdiff