move Rust sources to top level, C sources into c_src

This moves the Rust sources out of rust_src/ and into the top level.
Running the bcachefs executable out of the development tree is now:

$ ./target/release/bcachefs command
or
$ cargo run --profile release -- command

instead of "./bcachefs command".

Building and installing is still:

$ make && make install

Signed-off-by: Thomas Bertschinger <tahbertschinger@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 38 insertions, 0 deletions

diff --git a/c_src/include/linux/page.h b/c_src/include/linux/page.h
new file mode 100644
index 00000000..111e5e68
--- /dev/null
+++ b/c_src/include/linux/page.h
@@ -0,0 +1,38 @@
+#ifndef _LINUX_PAGE_H
+#define _LINUX_PAGE_H
+
+#include <sys/user.h>
+
+struct page;
+
+#ifndef PAGE_SIZE
+
+#define PAGE_SIZE   4096UL
+#define PAGE_MASK   (~(PAGE_SIZE - 1))
+
+#endif
+
+#ifndef PAGE_SHIFT
+#define PAGE_SHIFT 12
+#endif
+
+
+#define virt_to_page(p)							\
+	((struct page *) (((unsigned long) (p)) & PAGE_MASK))
+#define offset_in_page(p)		((unsigned long) (p) & ~PAGE_MASK)
+
+#define page_address(p)			((void *) (p))
+
+#define kmap_atomic(page)		page_address(page)
+#define kunmap_atomic(addr)		do {} while (0)
+
+#define kmap_local_page(page)		page_address(page)
+#define kunmap_local(addr)		do {} while (0)
+
+#define PageHighMem(page)		false
+
+static const char zero_page[PAGE_SIZE];
+
+#define ZERO_PAGE(o)			((struct page *) &zero_page[0])
+
+#endif /* _LINUX_PAGE_H */