nios2: Memory management

This patch contains the initialisation of the memory blocks, MMU
attributes and the memory map.

Signed-off-by: Ley Foon Tan <lftan@altera.com>

1 files changed, 142 insertions, 0 deletions

diff --git a/arch/nios2/mm/init.c b/arch/nios2/mm/init.c
new file mode 100644
index 000000000000..e75c75d249d6
--- /dev/null
+++ b/arch/nios2/mm/init.c
@@ -0,0 +1,142 @@
+/*
+ * Copyright (C) 2013 Altera Corporation
+ * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
+ * Copyright (C) 2009 Wind River Systems Inc
+ *   Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
+ * Copyright (C) 2004 Microtronix Datacom Ltd
+ *
+ * based on arch/m68k/mm/init.c
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/pagemap.h>
+#include <linux/bootmem.h>
+#include <linux/slab.h>
+#include <linux/binfmts.h>
+
+#include <asm/setup.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/sections.h>
+#include <asm/tlb.h>
+#include <asm/mmu_context.h>
+#include <asm/cpuinfo.h>
+#include <asm/processor.h>
+
+pgd_t *pgd_current;
+
+/*
+ * paging_init() continues the virtual memory environment setup which
+ * was begun by the code in arch/head.S.
+ * The parameters are pointers to where to stick the starting and ending
+ * addresses of available kernel virtual memory.
+ */
+void __init paging_init(void)
+{
+	unsigned long zones_size[MAX_NR_ZONES];
+
+	memset(zones_size, 0, sizeof(zones_size));
+
+	pagetable_init();
+	pgd_current = swapper_pg_dir;
+
+	zones_size[ZONE_NORMAL] = max_mapnr;
+
+	/* pass the memory from the bootmem allocator to the main allocator */
+	free_area_init(zones_size);
+
+	flush_dcache_range((unsigned long)empty_zero_page,
+			(unsigned long)empty_zero_page + PAGE_SIZE);
+}
+
+void __init mem_init(void)
+{
+	unsigned long end_mem   = memory_end; /* this must not include
+						kernel stack at top */
+
+	pr_debug("mem_init: start=%lx, end=%lx\n", memory_start, memory_end);
+
+	end_mem &= PAGE_MASK;
+	high_memory = __va(end_mem);
+
+	/* this will put all memory onto the freelists */
+	free_all_bootmem();
+	mem_init_print_info(NULL);
+}
+
+void __init mmu_init(void)
+{
+	flush_tlb_all();
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void __init free_initrd_mem(unsigned long start, unsigned long end)
+{
+	free_reserved_area((void *)start, (void *)end, -1, "initrd");
+}
+#endif
+
+void __init_refok free_initmem(void)
+{
+	free_initmem_default(-1);
+}
+
+#define __page_aligned(order) __aligned(PAGE_SIZE << (order))
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned(PGD_ORDER);
+pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);
+static struct page *kuser_page[1];
+
+static int alloc_kuser_page(void)
+{
+	extern char __kuser_helper_start[], __kuser_helper_end[];
+	int kuser_sz = __kuser_helper_end - __kuser_helper_start;
+	unsigned long vpage;
+
+	vpage = get_zeroed_page(GFP_ATOMIC);
+	if (!vpage)
+		return -ENOMEM;
+
+	/* Copy kuser helpers */
+	memcpy((void *)vpage, __kuser_helper_start, kuser_sz);
+
+	flush_icache_range(vpage, vpage + KUSER_SIZE);
+	kuser_page[0] = virt_to_page(vpage);
+
+	return 0;
+}
+arch_initcall(alloc_kuser_page);
+
+int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
+{
+	struct mm_struct *mm = current->mm;
+	int ret;
+
+	down_write(&mm->mmap_sem);
+
+	/* Map kuser helpers to user space address */
+	ret = install_special_mapping(mm, KUSER_BASE, KUSER_SIZE,
+				      VM_READ | VM_EXEC | VM_MAYREAD |
+				      VM_MAYEXEC, kuser_page);
+
+	up_write(&mm->mmap_sem);
+
+	return ret;
+}
+
+const char *arch_vma_name(struct vm_area_struct *vma)
+{
+	return (vma->vm_start == KUSER_BASE) ? "[kuser]" : NULL;
+}