sandbox: Add architecture header files

This adds required header files for the sandbox architecture, and a basic
description of what sandbox is (README.sandbox).

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/sandbox/include/asm/bitops.h b/arch/sandbox/include/asm/bitops.h
new file mode 100644
index 0000000..74219c5
--- /dev/null
+++ b/arch/sandbox/include/asm/bitops.h
@@ -0,0 +1,162 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ *
+ * Copyright 1995, Russell King.
+ * Various bits and pieces copyrights include:
+ *  Linus Torvalds (test_bit).
+ *
+ * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
+ *
+ * Please note that the code in this file should never be included
+ * from user space.  Many of these are not implemented in assembler
+ * since they would be too costly.  Also, they require priviledged
+ * instructions (which are not available from user mode) to ensure
+ * that they are atomic.
+ */
+
+#ifndef __ASM_SANDBOX_BITOPS_H
+#define __ASM_SANDBOX_BITOPS_H
+
+#include <asm/system.h>
+
+#ifdef __KERNEL__
+
+#define smp_mb__before_clear_bit()	do { } while (0)
+#define smp_mb__after_clear_bit()	do { } while (0)
+
+/*
+ * Function prototypes to keep gcc -Wall happy.
+ */
+extern void set_bit(int nr, void *addr);
+
+extern void clear_bit(int nr, void *addr);
+
+extern void change_bit(int nr, void *addr);
+
+static inline void __change_bit(int nr, void *addr)
+{
+	unsigned long mask = BIT_MASK(nr);
+	unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
+
+	*p ^= mask;
+}
+
+static inline int __test_and_set_bit(int nr, void *addr)
+{
+	unsigned long mask = BIT_MASK(nr);
+	unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
+	unsigned long old = *p;
+
+	*p = old | mask;
+	return (old & mask) != 0;
+}
+
+static inline int test_and_set_bit(int nr, void *addr)
+{
+	unsigned long flags;
+	int out;
+
+	local_irq_save(flags);
+	out = __test_and_set_bit(nr, addr);
+	local_irq_restore(flags);
+
+	return out;
+}
+
+static inline int __test_and_clear_bit(int nr, void *addr)
+{
+	unsigned long mask = BIT_MASK(nr);
+	unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
+	unsigned long old = *p;
+
+	*p = old & ~mask;
+	return (old & mask) != 0;
+}
+
+static inline int test_and_clear_bit(int nr, void *addr)
+{
+	unsigned long flags;
+	int out;
+
+	local_irq_save(flags);
+	out = __test_and_clear_bit(nr, addr);
+	local_irq_restore(flags);
+
+	return out;
+}
+
+extern int test_and_change_bit(int nr, void *addr);
+
+static inline int __test_and_change_bit(int nr, void *addr)
+{
+	unsigned long mask = BIT_MASK(nr);
+	unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
+	unsigned long old = *p;
+
+	*p = old ^ mask;
+	return (old & mask) != 0;
+}
+
+extern int find_first_zero_bit(void *addr, unsigned size);
+extern int find_next_zero_bit(void *addr, int size, int offset);
+
+/*
+ * This routine doesn't need to be atomic.
+ */
+static inline int test_bit(int nr, const void *addr)
+{
+	return ((unsigned char *) addr)[nr >> 3] & (1U << (nr & 7));
+}
+
+/*
+ * ffz = Find First Zero in word. Undefined if no zero exists,
+ * so code should check against ~0UL first..
+ */
+static inline unsigned long ffz(unsigned long word)
+{
+	int k;
+
+	word = ~word;
+	k = 31;
+	if (word & 0x0000ffff) {
+		k -= 16; word <<= 16;
+	}
+	if (word & 0x00ff0000) {
+		k -= 8;  word <<= 8;
+	}
+	if (word & 0x0f000000) {
+		k -= 4;  word <<= 4;
+	}
+	if (word & 0x30000000) {
+		k -= 2;  word <<= 2;
+	}
+	if (word & 0x40000000)
+		k -= 1;
+	return k;
+}
+
+/*
+ * hweightN: returns the hamming weight (i.e. the number
+ * of bits set) of a N-bit word
+ */
+
+#define hweight32(x) generic_hweight32(x)
+#define hweight16(x) generic_hweight16(x)
+#define hweight8(x) generic_hweight8(x)
+
+#define ext2_set_bit			test_and_set_bit
+#define ext2_clear_bit			test_and_clear_bit
+#define ext2_test_bit			test_bit
+#define ext2_find_first_zero_bit	find_first_zero_bit
+#define ext2_find_next_zero_bit		find_next_zero_bit
+
+/* Bitmap functions for the minix filesystem. */
+#define minix_test_and_set_bit(nr, addr)	test_and_set_bit(nr, addr)
+#define minix_set_bit(nr, addr)			set_bit(nr, addr)
+#define minix_test_and_clear_bit(nr, addr)	test_and_clear_bit(nr, addr)
+#define minix_test_bit(nr, addr)		test_bit(nr, addr)
+#define minix_find_first_zero_bit(addr, size)	find_first_zero_bit(addr, size)
+
+#endif /* __KERNEL__ */
+
+#endif /* _ARM_BITOPS_H */