1 files changed, 129 insertions, 0 deletions

diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c
new file mode 100644
index 000000000..00fe90c6d
--- /dev/null
+++ b/arch/mips/mm/mmap.c
@@ -0,0 +1,129 @@
+/*
+ * 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.
+ *
+ * Copyright (C) 2011 Wind River Systems,
+ *   written by Ralf Baechle <ralf@linux-mips.org>
+ */
+#include <linux/compiler.h>
+#include <linux/elf-randomize.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/export.h>
+#include <linux/personality.h>
+#include <linux/random.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/mm.h>
+
+unsigned long shm_align_mask = PAGE_SIZE - 1;   /* Sane caches */
+EXPORT_SYMBOL(shm_align_mask);
+
+#define COLOUR_ALIGN(addr, pgoff)                               \
+        ((((addr) + shm_align_mask) & ~shm_align_mask) +        \
+         (((pgoff) << PAGE_SHIFT) & shm_align_mask))
+
+enum mmap_allocation_direction {UP, DOWN};
+
+static unsigned long arch_get_unmapped_area_common(struct file *filp,
+        unsigned long addr0, unsigned long len, unsigned long pgoff,
+        unsigned long flags, enum mmap_allocation_direction dir)
+{
+        struct mm_struct *mm = current->mm;
+        struct vm_area_struct *vma;
+        unsigned long addr = addr0;
+        int do_color_align;
+        struct vm_unmapped_area_info info;
+
+        if (unlikely(len > TASK_SIZE))
+                return -ENOMEM;
+
+        if (flags & MAP_FIXED) {
+                /* Even MAP_FIXED mappings must reside within TASK_SIZE */
+                if (TASK_SIZE - len < addr)
+                        return -EINVAL;
+
+                /*
+                 * We do not accept a shared mapping if it would violate
+                 * cache aliasing constraints.
+                 */
+                if ((flags & MAP_SHARED) &&
+                    ((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))
+                        return -EINVAL;
+                return addr;
+        }
+
+        do_color_align = 0;
+        if (filp || (flags & MAP_SHARED))
+                do_color_align = 1;
+
+        /* requesting a specific address */
+        if (addr) {
+                if (do_color_align)
+                        addr = COLOUR_ALIGN(addr, pgoff);
+                else
+                        addr = PAGE_ALIGN(addr);
+
+                vma = find_vma(mm, addr);
+                if (TASK_SIZE - len >= addr &&
+                    (!vma || addr + len <= vm_start_gap(vma)))
+                        return addr;
+        }
+
+        info.length = len;
+        info.align_mask = do_color_align ? (PAGE_MASK & shm_align_mask) : 0;
+        info.align_offset = pgoff << PAGE_SHIFT;
+
+        if (dir == DOWN) {
+                info.flags = VM_UNMAPPED_AREA_TOPDOWN;
+                info.low_limit = PAGE_SIZE;
+                info.high_limit = mm->mmap_base;
+                addr = vm_unmapped_area(&info);
+
+                if (!(addr & ~PAGE_MASK))
+                        return addr;
+
+                /*
+                 * A failed mmap() very likely causes application failure,
+                 * so fall back to the bottom-up function here. This scenario
+                 * can happen with large stack limits and large mmap()
+                 * allocations.
+                 */
+        }
+
+        info.flags = 0;
+        info.low_limit = mm->mmap_base;
+        info.high_limit = TASK_SIZE;
+        return vm_unmapped_area(&info);
+}
+
+unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr0,
+        unsigned long len, unsigned long pgoff, unsigned long flags)
+{
+        return arch_get_unmapped_area_common(filp,
+                        addr0, len, pgoff, flags, UP);
+}
+
+/*
+ * There is no need to export this but sched.h declares the function as
+ * extern so making it static here results in an error.
+ */
+unsigned long arch_get_unmapped_area_topdown(struct file *filp,
+        unsigned long addr0, unsigned long len, unsigned long pgoff,
+        unsigned long flags)
+{
+        return arch_get_unmapped_area_common(filp,
+                        addr0, len, pgoff, flags, DOWN);
+}
+
+bool __virt_addr_valid(const volatile void *kaddr)
+{
+        unsigned long vaddr = (unsigned long)kaddr;
+
+        if ((vaddr < PAGE_OFFSET) || (vaddr >= MAP_BASE))
+                return false;
+
+        return pfn_valid(PFN_DOWN(virt_to_phys(kaddr)));
+}
+EXPORT_SYMBOL_GPL(__virt_addr_valid);