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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /arch/nds32/mm/mmap.c
parentInitial commit. (diff)
downloadlinux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz
linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/nds32/mm/mmap.c')
-rw-r--r--arch/nds32/mm/mmap.c73
1 files changed, 73 insertions, 0 deletions
diff --git a/arch/nds32/mm/mmap.c b/arch/nds32/mm/mmap.c
new file mode 100644
index 000000000..1bdf5e7d1
--- /dev/null
+++ b/arch/nds32/mm/mmap.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/sched.h>
+#include <linux/mman.h>
+#include <linux/shm.h>
+
+#define COLOUR_ALIGN(addr,pgoff) \
+ ((((addr)+SHMLBA-1)&~(SHMLBA-1)) + \
+ (((pgoff)<<PAGE_SHIFT) & (SHMLBA-1)))
+
+/*
+ * We need to ensure that shared mappings are correctly aligned to
+ * avoid aliasing issues with VIPT caches. We need to ensure that
+ * a specific page of an object is always mapped at a multiple of
+ * SHMLBA bytes.
+ *
+ * We unconditionally provide this function for all cases, however
+ * in the VIVT case, we optimise out the alignment rules.
+ */
+unsigned long
+arch_get_unmapped_area(struct file *filp, unsigned long addr,
+ unsigned long len, unsigned long pgoff,
+ unsigned long flags)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ int do_align = 0;
+ struct vm_unmapped_area_info info;
+ int aliasing = 0;
+ if(IS_ENABLED(CONFIG_CPU_CACHE_ALIASING))
+ aliasing = 1;
+
+ /*
+ * We only need to do colour alignment if either the I or D
+ * caches alias.
+ */
+ if (aliasing)
+ do_align = filp || (flags & MAP_SHARED);
+
+ /*
+ * We enforce the MAP_FIXED case.
+ */
+ if (flags & MAP_FIXED) {
+ if (aliasing && flags & MAP_SHARED &&
+ (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
+ return -EINVAL;
+ return addr;
+ }
+
+ if (len > TASK_SIZE)
+ return -ENOMEM;
+
+ if (addr) {
+ if (do_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.flags = 0;
+ info.length = len;
+ info.low_limit = mm->mmap_base;
+ info.high_limit = TASK_SIZE;
+ info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
+ info.align_offset = pgoff << PAGE_SHIFT;
+ return vm_unmapped_area(&info);
+}