This adds vm_iomap_memory() from:
commit b4cbb197c7e7a68dbad0d491242e3ca67420c13e
Author: Linus Torvalds <[email protected]>
Date: Tue Apr 16 13:45:37 2013 -0700
vm: add vm_iomap_memory() helper function
Signed-off-by: Hauke Mehrtens <[email protected]>
---
backport/backport-include/linux/mm.h | 5 ++++
backport/compat/compat-3.8.c | 55 ++++++++++++++++++++++++++++++++++
2 files changed, 60 insertions(+)
diff --git a/backport/backport-include/linux/mm.h
b/backport/backport-include/linux/mm.h
index 9ba1f00..8671d29 100644
--- a/backport/backport-include/linux/mm.h
+++ b/backport/backport-include/linux/mm.h
@@ -20,4 +20,9 @@
#define VM_DONTDUMP VM_NODUMP
#endif
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(3,8,0))
+#define vm_iomap_memory LINUX_BACKPORT(vm_iomap_memory)
+int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned
long len);
+#endif
+
#endif /* __BACKPORT_MM_H */
diff --git a/backport/compat/compat-3.8.c b/backport/compat/compat-3.8.c
index 9f5df7d..5b1ead9 100644
--- a/backport/compat/compat-3.8.c
+++ b/backport/compat/compat-3.8.c
@@ -363,3 +363,58 @@ bool hid_ignore(struct hid_device *hdev)
return !!hid_match_id(hdev, hid_ignore_list);
}
EXPORT_SYMBOL_GPL(hid_ignore);
+
+/**
+ * Backport this:
+ * commit b4cbb197c7e7a68dbad0d491242e3ca67420c13e
+ * Author: Linus Torvalds <[email protected]>
+ * Date: Tue Apr 16 13:45:37 2013 -0700
+ *
+ * vm: add vm_iomap_memory() helper function
+ */
+/**
+ * vm_iomap_memory - remap memory to userspace
+ * @vma: user vma to map to
+ * @start: start of area
+ * @len: size of area
+ *
+ * This is a simplified io_remap_pfn_range() for common driver use. The
+ * driver just needs to give us the physical memory range to be mapped,
+ * we'll figure out the rest from the vma information.
+ *
+ * NOTE! Some drivers might want to tweak vma->vm_page_prot first to get
+ * whatever write-combining details or similar.
+ */
+int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned
long len)
+{
+ unsigned long vm_len, pfn, pages;
+
+ /* Check that the physical memory area passed in looks valid */
+ if (start + len < start)
+ return -EINVAL;
+ /*
+ * You *really* shouldn't map things that aren't page-aligned,
+ * but we've historically allowed it because IO memory might
+ * just have smaller alignment.
+ */
+ len += start & ~PAGE_MASK;
+ pfn = start >> PAGE_SHIFT;
+ pages = (len + ~PAGE_MASK) >> PAGE_SHIFT;
+ if (pfn + pages < pfn)
+ return -EINVAL;
+
+ /* We start the mapping 'vm_pgoff' pages into the area */
+ if (vma->vm_pgoff > pages)
+ return -EINVAL;
+ pfn += vma->vm_pgoff;
+ pages -= vma->vm_pgoff;
+
+ /* Can we fit all of the mapping? */
+ vm_len = vma->vm_end - vma->vm_start;
+ if (vm_len >> PAGE_SHIFT > pages)
+ return -EINVAL;
+
+ /* Ok, let it rip */
+ return io_remap_pfn_range(vma, vma->vm_start, pfn, vm_len,
vma->vm_page_prot);
+}
+EXPORT_SYMBOL(vm_iomap_memory);
--
1.7.10.4
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