Merge tag 'gpmc-omap-v4.8-rc1' of https://github.com/rogerq/linux into fixes

[cascardo/linux.git] / arch / arm64 / kernel / hibernate.c

diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
index 21ab5df..65d81f9 100644 (file)
--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -35,6 +35,7 @@
 #include <asm/sections.h>
 #include <asm/smp.h>
 #include <asm/suspend.h>
+#include <asm/sysreg.h>
 #include <asm/virt.h>
 
 /*
@@ -217,12 +218,22 @@ static int create_safe_exec_page(void *src_start, size_t length,
        set_pte(pte, __pte(virt_to_phys((void *)dst) |
                         pgprot_val(PAGE_KERNEL_EXEC)));
 
-       /* Load our new page tables */
-       asm volatile("msr       ttbr0_el1, %0;"
-                    "isb;"
-                    "tlbi      vmalle1is;"
-                    "dsb       ish;"
-                    "isb" : : "r"(virt_to_phys(pgd)));
+       /*
+        * Load our new page tables. A strict BBM approach requires that we
+        * ensure that TLBs are free of any entries that may overlap with the
+        * global mappings we are about to install.
+        *
+        * For a real hibernate/resume cycle TTBR0 currently points to a zero
+        * page, but TLBs may contain stale ASID-tagged entries (e.g. for EFI
+        * runtime services), while for a userspace-driven test_resume cycle it
+        * points to userspace page tables (and we must point it at a zero page
+        * ourselves). Elsewhere we only (un)install the idmap with preemption
+        * disabled, so T0SZ should be as required regardless.
+        */
+       cpu_set_reserved_ttbr0();
+       local_flush_tlb_all();
+       write_sysreg(virt_to_phys(pgd), ttbr0_el1);
+       isb();
 
        *phys_dst_addr = virt_to_phys((void *)dst);
 
@@ -393,6 +404,38 @@ int swsusp_arch_resume(void)
        void __noreturn (*hibernate_exit)(phys_addr_t, phys_addr_t, void *,
                                          void *, phys_addr_t, phys_addr_t);
 
+       /*
+        * Restoring the memory image will overwrite the ttbr1 page tables.
+        * Create a second copy of just the linear map, and use this when
+        * restoring.
+        */
+       tmp_pg_dir = (pgd_t *)get_safe_page(GFP_ATOMIC);
+       if (!tmp_pg_dir) {
+               pr_err("Failed to allocate memory for temporary page tables.");
+               rc = -ENOMEM;
+               goto out;
+       }
+       rc = copy_page_tables(tmp_pg_dir, PAGE_OFFSET, 0);
+       if (rc)
+               goto out;
+
+       /*
+        * Since we only copied the linear map, we need to find restore_pblist's
+        * linear map address.
+        */
+       lm_restore_pblist = LMADDR(restore_pblist);
+
+       /*
+        * We need a zero page that is zero before & after resume in order to
+        * to break before make on the ttbr1 page tables.
+        */
+       zero_page = (void *)get_safe_page(GFP_ATOMIC);
+       if (!zero_page) {
+               pr_err("Failed to allocate zero page.");
+               rc = -ENOMEM;
+               goto out;
+       }
+
        /*
         * Locate the exit code in the bottom-but-one page, so that *NULL
         * still has disastrous affects.
@@ -418,27 +461,6 @@ int swsusp_arch_resume(void)
         */
        __flush_dcache_area(hibernate_exit, exit_size);
 
-       /*
-        * Restoring the memory image will overwrite the ttbr1 page tables.
-        * Create a second copy of just the linear map, and use this when
-        * restoring.
-        */
-       tmp_pg_dir = (pgd_t *)get_safe_page(GFP_ATOMIC);
-       if (!tmp_pg_dir) {
-               pr_err("Failed to allocate memory for temporary page tables.");
-               rc = -ENOMEM;
-               goto out;
-       }
-       rc = copy_page_tables(tmp_pg_dir, PAGE_OFFSET, 0);
-       if (rc)
-               goto out;
-
-       /*
-        * Since we only copied the linear map, we need to find restore_pblist's
-        * linear map address.
-        */
-       lm_restore_pblist = LMADDR(restore_pblist);
-
        /*
         * KASLR will cause the el2 vectors to be in a different location in
         * the resumed kernel. Load hibernate's temporary copy into el2.
@@ -453,12 +475,6 @@ int swsusp_arch_resume(void)
                __hyp_set_vectors(el2_vectors);
        }
 
-       /*
-        * We need a zero page that is zero before & after resume in order to
-        * to break before make on the ttbr1 page tables.
-        */
-       zero_page = (void *)get_safe_page(GFP_ATOMIC);
-
        hibernate_exit(virt_to_phys(tmp_pg_dir), resume_hdr.ttbr1_el1,
                       resume_hdr.reenter_kernel, lm_restore_pblist,
                       resume_hdr.__hyp_stub_vectors, virt_to_phys(zero_page));