Migrate swapper_pg_dir and tramp_pg_dir. And their virtual addresses
do not correlate with kernel's address.

Signed-off-by: Jun Yao <yaojun8558...@gmail.com>
---
 arch/arm64/mm/mmu.c | 70 +++++++++++++++++++++++++++------------------
 1 file changed, 42 insertions(+), 28 deletions(-)

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 26ba3e70a91c..5baae59479d8 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -57,6 +57,9 @@ EXPORT_SYMBOL(kimage_voffset);
 
 phys_addr_t __pa_swapper_pg_dir;
 pgd_t *new_swapper_pg_dir = swapper_pg_dir;
+#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
+pgd_t *new_tramp_pg_dir;
+#endif
 
 /*
  * Empty_zero_page is a special page that is used for zero-initialized data
@@ -80,19 +83,14 @@ pgprot_t phys_mem_access_prot(struct file *file, unsigned 
long pfn,
 }
 EXPORT_SYMBOL(phys_mem_access_prot);
 
-static phys_addr_t __init early_pgtable_alloc(void)
+static void __init clear_page_phys(phys_addr_t phys)
 {
-       phys_addr_t phys;
-       void *ptr;
-
-       phys = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
-
        /*
         * The FIX_{PGD,PUD,PMD} slots may be in active use, but the FIX_PTE
         * slot will be free, so we can (ab)use the FIX_PTE slot to initialise
         * any level of table.
         */
-       ptr = pte_set_fixmap(phys);
+       void *ptr = pte_set_fixmap(phys);
 
        memset(ptr, 0, PAGE_SIZE);
 
@@ -101,6 +99,14 @@ static phys_addr_t __init early_pgtable_alloc(void)
         * table walker
         */
        pte_clear_fixmap();
+}
+
+static phys_addr_t __init early_pgtable_alloc(void)
+{
+       phys_addr_t phys;
+
+       phys = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+       clear_page_phys(phys);
 
        return phys;
 }
@@ -554,6 +560,10 @@ static int __init map_entry_trampoline(void)
        __create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, PAGE_SIZE,
                             prot, pgd_pgtable_alloc, 0);
 
+       memcpy(new_tramp_pg_dir, tramp_pg_dir, PGD_SIZE);
+       memblock_free(__pa_symbol(tramp_pg_dir),
+               __pa_symbol(swapper_pg_dir) - __pa_symbol(tramp_pg_dir));
+
        /* Map both the text and data into the kernel page table */
        __set_fixmap(FIX_ENTRY_TRAMP_TEXT, pa_start, prot);
        if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
@@ -631,36 +641,40 @@ static void __init map_kernel(pgd_t *pgdp)
  */
 void __init paging_init(void)
 {
-       phys_addr_t pgd_phys = early_pgtable_alloc();
-       pgd_t *pgdp = pgd_set_fixmap(pgd_phys);
+       phys_addr_t pgd_phys;
+       pgd_t *pgdp;
+
+#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
+       phys_addr_t mem_size;
+       phys_addr_t p;
 
-       __pa_swapper_pg_dir = __pa_symbol(swapper_pg_dir);
+       mem_size = __pa_symbol(swapper_pg_dir) + PAGE_SIZE
+                               - __pa_symbol(tramp_pg_dir);
+       pgd_phys = memblock_alloc(mem_size, PAGE_SIZE);
+
+       for (p = pgd_phys; p < pgd_phys + mem_size; p += PAGE_SIZE)
+               clear_page_phys(p);
+
+       new_tramp_pg_dir = __va(pgd_phys);
+       __pa_swapper_pg_dir = pgd_phys + PAGE_SIZE;
+#else
+       pgd_phys = early_pgtable_alloc();
+       __pa_swapper_pg_dir = pgd_phys;
+#endif
+       new_swapper_pg_dir = __va(__pa_swapper_pg_dir);
+
+       pgdp = pgd_set_fixmap(__pa_swapper_pg_dir);
 
        map_kernel(pgdp);
        map_mem(pgdp);
 
-       /*
-        * We want to reuse the original swapper_pg_dir so we don't have to
-        * communicate the new address to non-coherent secondaries in
-        * secondary_entry, and so cpu_switch_mm can generate the address with
-        * adrp+add rather than a load from some global variable.
-        *
-        * To do this we need to go via a temporary pgd.
-        */
-       cpu_replace_ttbr1(pgd_phys);
-       memcpy(swapper_pg_dir, pgdp, PGD_SIZE);
        cpu_replace_ttbr1(__pa_swapper_pg_dir);
+       init_mm.pgd = new_swapper_pg_dir;
 
        pgd_clear_fixmap();
-       memblock_free(pgd_phys, PAGE_SIZE);
 
-       /*
-        * We only reuse the PGD from the swapper_pg_dir, not the pud + pmd
-        * allocated with it.
-        */
-       memblock_free(__pa_symbol(swapper_pg_dir) + PAGE_SIZE,
-                     __pa_symbol(swapper_pg_end) - __pa_symbol(swapper_pg_dir)
-                     - PAGE_SIZE);
+       memblock_free(__pa_symbol(swapper_pg_dir),
+               __pa_symbol(swapper_pg_end) - __pa_symbol(swapper_pg_dir));
 }
 
 /*
-- 
2.17.0

Reply via email to