[Feature] add GA346 baseline version
Change-Id: Ic62933698569507dcf98240cdf5d9931ae34348f
diff --git a/src/kernel/linux/v4.19/arch/nds32/mm/mm-nds32.c b/src/kernel/linux/v4.19/arch/nds32/mm/mm-nds32.c
new file mode 100644
index 0000000..3b43798
--- /dev/null
+++ b/src/kernel/linux/v4.19/arch/nds32/mm/mm-nds32.c
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/init_task.h>
+#include <asm/pgalloc.h>
+
+#define FIRST_KERNEL_PGD_NR (USER_PTRS_PER_PGD)
+
+/*
+ * need to get a page for level 1
+ */
+
+pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+ pgd_t *new_pgd, *init_pgd;
+ int i;
+
+ new_pgd = (pgd_t *) __get_free_pages(GFP_KERNEL, 0);
+ if (!new_pgd)
+ return NULL;
+ for (i = 0; i < PTRS_PER_PGD; i++) {
+ (*new_pgd) = 1;
+ new_pgd++;
+ }
+ new_pgd -= PTRS_PER_PGD;
+
+ init_pgd = pgd_offset_k(0);
+
+ memcpy(new_pgd + FIRST_KERNEL_PGD_NR, init_pgd + FIRST_KERNEL_PGD_NR,
+ (PTRS_PER_PGD - FIRST_KERNEL_PGD_NR) * sizeof(pgd_t));
+
+ cpu_dcache_wb_range((unsigned long)new_pgd,
+ (unsigned long)new_pgd +
+ PTRS_PER_PGD * sizeof(pgd_t));
+ inc_zone_page_state(virt_to_page((unsigned long *)new_pgd),
+ NR_PAGETABLE);
+
+ return new_pgd;
+}
+
+void pgd_free(struct mm_struct *mm, pgd_t * pgd)
+{
+ pmd_t *pmd;
+ struct page *pte;
+
+ if (!pgd)
+ return;
+
+ pmd = (pmd_t *) pgd;
+ if (pmd_none(*pmd))
+ goto free;
+ if (pmd_bad(*pmd)) {
+ pmd_ERROR(*pmd);
+ pmd_clear(pmd);
+ goto free;
+ }
+
+ pte = pmd_page(*pmd);
+ pmd_clear(pmd);
+ dec_zone_page_state(virt_to_page((unsigned long *)pgd), NR_PAGETABLE);
+ pte_free(mm, pte);
+ mm_dec_nr_ptes(mm);
+ pmd_free(mm, pmd);
+free:
+ free_pages((unsigned long)pgd, 0);
+}
+
+/*
+ * In order to soft-boot, we need to insert a 1:1 mapping in place of
+ * the user-mode pages. This will then ensure that we have predictable
+ * results when turning the mmu off
+ */
+void setup_mm_for_reboot(char mode)
+{
+ unsigned long pmdval;
+ pgd_t *pgd;
+ pmd_t *pmd;
+ int i;
+
+ if (current->mm && current->mm->pgd)
+ pgd = current->mm->pgd;
+ else
+ pgd = init_mm.pgd;
+
+ for (i = 0; i < USER_PTRS_PER_PGD; i++) {
+ pmdval = (i << PGDIR_SHIFT);
+ pmd = pmd_offset(pgd + i, i << PGDIR_SHIFT);
+ set_pmd(pmd, __pmd(pmdval));
+ }
+}