Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 237 insertions, 0 deletions

diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
new file mode 100644
index 000000000..3c0e470ea
--- /dev/null
+++ b/arch/um/kernel/mem.c
@@ -0,0 +1,237 @@
+/*
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#include <linux/stddef.h>
+#include <linux/module.h>
+#include <linux/bootmem.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/slab.h>
+#include <asm/fixmap.h>
+#include <asm/page.h>
+#include <as-layout.h>
+#include <init.h>
+#include <kern.h>
+#include <kern_util.h>
+#include <mem_user.h>
+#include <os.h>
+
+/* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
+unsigned long *empty_zero_page = NULL;
+EXPORT_SYMBOL(empty_zero_page);
+
+/*
+ * Initialized during boot, and readonly for initializing page tables
+ * afterwards
+ */
+pgd_t swapper_pg_dir[PTRS_PER_PGD];
+
+/* Initialized at boot time, and readonly after that */
+unsigned long long highmem;
+int kmalloc_ok = 0;
+
+/* Used during early boot */
+static unsigned long brk_end;
+
+void __init mem_init(void)
+{
+	/* clear the zero-page */
+	memset(empty_zero_page, 0, PAGE_SIZE);
+
+	/* Map in the area just after the brk now that kmalloc is about
+	 * to be turned on.
+	 */
+	brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
+	map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
+	free_bootmem(__pa(brk_end), uml_reserved - brk_end);
+	uml_reserved = brk_end;
+
+	/* this will put all low memory onto the freelists */
+	free_all_bootmem();
+	max_low_pfn = totalram_pages;
+	max_pfn = totalram_pages;
+	mem_init_print_info(NULL);
+	kmalloc_ok = 1;
+}
+
+/*
+ * Create a page table and place a pointer to it in a middle page
+ * directory entry.
+ */
+static void __init one_page_table_init(pmd_t *pmd)
+{
+	if (pmd_none(*pmd)) {
+		pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+		set_pmd(pmd, __pmd(_KERNPG_TABLE +
+					   (unsigned long) __pa(pte)));
+		if (pte != pte_offset_kernel(pmd, 0))
+			BUG();
+	}
+}
+
+static void __init one_md_table_init(pud_t *pud)
+{
+#ifdef CONFIG_3_LEVEL_PGTABLES
+	pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+	set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
+	if (pmd_table != pmd_offset(pud, 0))
+		BUG();
+#endif
+}
+
+static void __init fixrange_init(unsigned long start, unsigned long end,
+				 pgd_t *pgd_base)
+{
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	int i, j;
+	unsigned long vaddr;
+
+	vaddr = start;
+	i = pgd_index(vaddr);
+	j = pmd_index(vaddr);
+	pgd = pgd_base + i;
+
+	for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
+		pud = pud_offset(pgd, vaddr);
+		if (pud_none(*pud))
+			one_md_table_init(pud);
+		pmd = pmd_offset(pud, vaddr);
+		for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) {
+			one_page_table_init(pmd);
+			vaddr += PMD_SIZE;
+		}
+		j = 0;
+	}
+}
+
+static void __init fixaddr_user_init( void)
+{
+#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
+	long size = FIXADDR_USER_END - FIXADDR_USER_START;
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+	phys_t p;
+	unsigned long v, vaddr = FIXADDR_USER_START;
+
+	if (!size)
+		return;
+
+	fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
+	v = (unsigned long) alloc_bootmem_low_pages(size);
+	memcpy((void *) v , (void *) FIXADDR_USER_START, size);
+	p = __pa(v);
+	for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
+		      p += PAGE_SIZE) {
+		pgd = swapper_pg_dir + pgd_index(vaddr);
+		pud = pud_offset(pgd, vaddr);
+		pmd = pmd_offset(pud, vaddr);
+		pte = pte_offset_kernel(pmd, vaddr);
+		pte_set_val(*pte, p, PAGE_READONLY);
+	}
+#endif
+}
+
+void __init paging_init(void)
+{
+	unsigned long zones_size[MAX_NR_ZONES], vaddr;
+	int i;
+
+	empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
+	for (i = 0; i < ARRAY_SIZE(zones_size); i++)
+		zones_size[i] = 0;
+
+	zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) -
+		(uml_physmem >> PAGE_SHIFT);
+	free_area_init(zones_size);
+
+	/*
+	 * Fixed mappings, only the page table structure has to be
+	 * created - mappings will be set by set_fixmap():
+	 */
+	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
+	fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);
+
+	fixaddr_user_init();
+}
+
+/*
+ * This can't do anything because nothing in the kernel image can be freed
+ * since it's not in kernel physical memory.
+ */
+
+void free_initmem(void)
+{
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void free_initrd_mem(unsigned long start, unsigned long end)
+{
+	free_reserved_area((void *)start, (void *)end, -1, "initrd");
+}
+#endif
+
+/* Allocate and free page tables. */
+
+pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+	pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
+
+	if (pgd) {
+		memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
+		memcpy(pgd + USER_PTRS_PER_PGD,
+		       swapper_pg_dir + USER_PTRS_PER_PGD,
+		       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
+	}
+	return pgd;
+}
+
+void pgd_free(struct mm_struct *mm, pgd_t *pgd)
+{
+	free_page((unsigned long) pgd);
+}
+
+pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
+{
+	pte_t *pte;
+
+	pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
+	return pte;
+}
+
+pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
+{
+	struct page *pte;
+
+	pte = alloc_page(GFP_KERNEL|__GFP_ZERO);
+	if (!pte)
+		return NULL;
+	if (!pgtable_page_ctor(pte)) {
+		__free_page(pte);
+		return NULL;
+	}
+	return pte;
+}
+
+#ifdef CONFIG_3_LEVEL_PGTABLES
+pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
+{
+	pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL);
+
+	if (pmd)
+		memset(pmd, 0, PAGE_SIZE);
+
+	return pmd;
+}
+#endif
+
+void *uml_kmalloc(int size, int flags)
+{
+	return kmalloc(size, flags);
+}