[PATCH] xtensa: Architecture support for Tensilica Xtensa Part 6
The attached patches provides part 6 of an architecture implementation for the
Tensilica Xtensa CPU series.
Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/asm-xtensa/bitops.h b/include/asm-xtensa/bitops.h
new file mode 100644
index 0000000..d395ef2
--- /dev/null
+++ b/include/asm-xtensa/bitops.h
@@ -0,0 +1,446 @@
+/*
+ * include/asm-xtensa/bitops.h
+ *
+ * Atomic operations that C can't guarantee us.Useful for resource counting etc.
+ *
+ * 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) 2001 - 2005 Tensilica Inc.
+ */
+
+#ifndef _XTENSA_BITOPS_H
+#define _XTENSA_BITOPS_H
+
+#ifdef __KERNEL__
+
+#include <asm/processor.h>
+#include <asm/byteorder.h>
+#include <asm/system.h>
+
+#ifdef CONFIG_SMP
+# error SMP not supported on this architecture
+#endif
+
+static __inline__ void set_bit(int nr, volatile void * addr)
+{
+ unsigned long mask = 1 << (nr & 0x1f);
+ unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
+ unsigned long flags;
+
+ local_irq_save(flags);
+ *a |= mask;
+ local_irq_restore(flags);
+}
+
+static __inline__ void __set_bit(int nr, volatile unsigned long * addr)
+{
+ unsigned long mask = 1 << (nr & 0x1f);
+ unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
+
+ *a |= mask;
+}
+
+static __inline__ void clear_bit(int nr, volatile void * addr)
+{
+ unsigned long mask = 1 << (nr & 0x1f);
+ unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
+ unsigned long flags;
+
+ local_irq_save(flags);
+ *a &= ~mask;
+ local_irq_restore(flags);
+}
+
+static __inline__ void __clear_bit(int nr, volatile unsigned long *addr)
+{
+ unsigned long mask = 1 << (nr & 0x1f);
+ unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
+
+ *a &= ~mask;
+}
+
+/*
+ * clear_bit() doesn't provide any barrier for the compiler.
+ */
+
+#define smp_mb__before_clear_bit() barrier()
+#define smp_mb__after_clear_bit() barrier()
+
+static __inline__ void change_bit(int nr, volatile void * addr)
+{
+ unsigned long mask = 1 << (nr & 0x1f);
+ unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
+ unsigned long flags;
+
+ local_irq_save(flags);
+ *a ^= mask;
+ local_irq_restore(flags);
+}
+
+static __inline__ void __change_bit(int nr, volatile void * addr)
+{
+ unsigned long mask = 1 << (nr & 0x1f);
+ unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
+
+ *a ^= mask;
+}
+
+static __inline__ int test_and_set_bit(int nr, volatile void * addr)
+{
+ unsigned long retval;
+ unsigned long mask = 1 << (nr & 0x1f);
+ unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
+ unsigned long flags;
+
+ local_irq_save(flags);
+ retval = (mask & *a) != 0;
+ *a |= mask;
+ local_irq_restore(flags);
+
+ return retval;
+}
+
+static __inline__ int __test_and_set_bit(int nr, volatile void * addr)
+{
+ unsigned long retval;
+ unsigned long mask = 1 << (nr & 0x1f);
+ unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
+
+ retval = (mask & *a) != 0;
+ *a |= mask;
+
+ return retval;
+}
+
+static __inline__ int test_and_clear_bit(int nr, volatile void * addr)
+{
+ unsigned long retval;
+ unsigned long mask = 1 << (nr & 0x1f);
+ unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
+ unsigned long flags;
+
+ local_irq_save(flags);
+ retval = (mask & *a) != 0;
+ *a &= ~mask;
+ local_irq_restore(flags);
+
+ return retval;
+}
+
+static __inline__ int __test_and_clear_bit(int nr, volatile void * addr)
+{
+ unsigned long mask = 1 << (nr & 0x1f);
+ unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
+ unsigned long old = *a;
+
+ *a = old & ~mask;
+ return (old & mask) != 0;
+}
+
+static __inline__ int test_and_change_bit(int nr, volatile void * addr)
+{
+ unsigned long retval;
+ unsigned long mask = 1 << (nr & 0x1f);
+ unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
+ unsigned long flags;
+
+ local_irq_save(flags);
+
+ retval = (mask & *a) != 0;
+ *a ^= mask;
+ local_irq_restore(flags);
+
+ return retval;
+}
+
+/*
+ * non-atomic version; can be reordered
+ */
+
+static __inline__ int __test_and_change_bit(int nr, volatile void *addr)
+{
+ unsigned long mask = 1 << (nr & 0x1f);
+ unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
+ unsigned long old = *a;
+
+ *a = old ^ mask;
+ return (old & mask) != 0;
+}
+
+static __inline__ int test_bit(int nr, const volatile void *addr)
+{
+ return 1UL & (((const volatile unsigned int *)addr)[nr>>5] >> (nr&31));
+}
+
+#if XCHAL_HAVE_NSAU
+
+static __inline__ int __cntlz (unsigned long x)
+{
+ int lz;
+ asm ("nsau %0, %1" : "=r" (lz) : "r" (x));
+ return 31 - lz;
+}
+
+#else
+
+static __inline__ int __cntlz (unsigned long x)
+{
+ unsigned long sum, x1, x2, x4, x8, x16;
+ x1 = x & 0xAAAAAAAA;
+ x2 = x & 0xCCCCCCCC;
+ x4 = x & 0xF0F0F0F0;
+ x8 = x & 0xFF00FF00;
+ x16 = x & 0xFFFF0000;
+ sum = x2 ? 2 : 0;
+ sum += (x16 != 0) * 16;
+ sum += (x8 != 0) * 8;
+ sum += (x4 != 0) * 4;
+ sum += (x1 != 0);
+
+ return sum;
+}
+
+#endif
+
+/*
+ * ffz: Find first zero in word. Undefined if no zero exists.
+ * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
+ */
+
+static __inline__ int ffz(unsigned long x)
+{
+ if ((x = ~x) == 0)
+ return 32;
+ return __cntlz(x & -x);
+}
+
+/*
+ * __ffs: Find first bit set in word. Return 0 for bit 0
+ */
+
+static __inline__ int __ffs(unsigned long x)
+{
+ return __cntlz(x & -x);
+}
+
+/*
+ * ffs: Find first bit set in word. This is defined the same way as
+ * the libc and compiler builtin ffs routines, therefore
+ * differs in spirit from the above ffz (man ffs).
+ */
+
+static __inline__ int ffs(unsigned long x)
+{
+ return __cntlz(x & -x) + 1;
+}
+
+/*
+ * fls: Find last (most-significant) bit set in word.
+ * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
+ */
+
+static __inline__ int fls (unsigned int x)
+{
+ return __cntlz(x);
+}
+
+static __inline__ int
+find_next_bit(const unsigned long *addr, int size, int offset)
+{
+ const unsigned long *p = addr + (offset >> 5);
+ unsigned long result = offset & ~31UL;
+ unsigned long tmp;
+
+ if (offset >= size)
+ return size;
+ size -= result;
+ offset &= 31UL;
+ if (offset) {
+ tmp = *p++;
+ tmp &= ~0UL << offset;
+ if (size < 32)
+ goto found_first;
+ if (tmp)
+ goto found_middle;
+ size -= 32;
+ result += 32;
+ }
+ while (size >= 32) {
+ if ((tmp = *p++) != 0)
+ goto found_middle;
+ result += 32;
+ size -= 32;
+ }
+ if (!size)
+ return result;
+ tmp = *p;
+
+found_first:
+ tmp &= ~0UL >> (32 - size);
+ if (tmp == 0UL) /* Are any bits set? */
+ return result + size; /* Nope. */
+found_middle:
+ return result + __ffs(tmp);
+}
+
+/**
+ * find_first_bit - find the first set bit in a memory region
+ * @addr: The address to start the search at
+ * @size: The maximum size to search
+ *
+ * Returns the bit-number of the first set bit, not the number of the byte
+ * containing a bit.
+ */
+
+#define find_first_bit(addr, size) \
+ find_next_bit((addr), (size), 0)
+
+static __inline__ int
+find_next_zero_bit(const unsigned long *addr, int size, int offset)
+{
+ const unsigned long *p = addr + (offset >> 5);
+ unsigned long result = offset & ~31UL;
+ unsigned long tmp;
+
+ if (offset >= size)
+ return size;
+ size -= result;
+ offset &= 31UL;
+ if (offset) {
+ tmp = *p++;
+ tmp |= ~0UL >> (32-offset);
+ if (size < 32)
+ goto found_first;
+ if (~tmp)
+ goto found_middle;
+ size -= 32;
+ result += 32;
+ }
+ while (size & ~31UL) {
+ if (~(tmp = *p++))
+ goto found_middle;
+ result += 32;
+ size -= 32;
+ }
+ if (!size)
+ return result;
+ tmp = *p;
+
+found_first:
+ tmp |= ~0UL << size;
+found_middle:
+ return result + ffz(tmp);
+}
+
+#define find_first_zero_bit(addr, size) \
+ find_next_zero_bit((addr), (size), 0)
+
+#ifdef __XTENSA_EL__
+# define ext2_set_bit(nr,addr) __test_and_set_bit((nr), (addr))
+# define ext2_set_bit_atomic(lock,nr,addr) test_and_set_bit((nr),(addr))
+# define ext2_clear_bit(nr,addr) __test_and_clear_bit((nr), (addr))
+# define ext2_clear_bit_atomic(lock,nr,addr) test_and_clear_bit((nr),(addr))
+# define ext2_test_bit(nr,addr) test_bit((nr), (addr))
+# define ext2_find_first_zero_bit(addr, size) find_first_zero_bit((addr),(size))
+# define ext2_find_next_zero_bit(addr, size, offset) \
+ find_next_zero_bit((addr), (size), (offset))
+#elif defined(__XTENSA_EB__)
+# define ext2_set_bit(nr,addr) __test_and_set_bit((nr) ^ 0x18, (addr))
+# define ext2_set_bit_atomic(lock,nr,addr) test_and_set_bit((nr) ^ 0x18, (addr))
+# define ext2_clear_bit(nr,addr) __test_and_clear_bit((nr) ^ 18, (addr))
+# define ext2_clear_bit_atomic(lock,nr,addr) test_and_clear_bit((nr)^0x18,(addr))
+# define ext2_test_bit(nr,addr) test_bit((nr) ^ 0x18, (addr))
+# define ext2_find_first_zero_bit(addr, size) \
+ ext2_find_next_zero_bit((addr), (size), 0)
+
+static __inline__ unsigned long ext2_find_next_zero_bit(void *addr, unsigned long size, unsigned long offset)
+{
+ unsigned long *p = ((unsigned long *) addr) + (offset >> 5);
+ unsigned long result = offset & ~31UL;
+ unsigned long tmp;
+
+ if (offset >= size)
+ return size;
+ size -= result;
+ offset &= 31UL;
+ if(offset) {
+ /* We hold the little endian value in tmp, but then the
+ * shift is illegal. So we could keep a big endian value
+ * in tmp, like this:
+ *
+ * tmp = __swab32(*(p++));
+ * tmp |= ~0UL >> (32-offset);
+ *
+ * but this would decrease preformance, so we change the
+ * shift:
+ */
+ tmp = *(p++);
+ tmp |= __swab32(~0UL >> (32-offset));
+ if(size < 32)
+ goto found_first;
+ if(~tmp)
+ goto found_middle;
+ size -= 32;
+ result += 32;
+ }
+ while(size & ~31UL) {
+ if(~(tmp = *(p++)))
+ goto found_middle;
+ result += 32;
+ size -= 32;
+ }
+ if(!size)
+ return result;
+ tmp = *p;
+
+found_first:
+ /* tmp is little endian, so we would have to swab the shift,
+ * see above. But then we have to swab tmp below for ffz, so
+ * we might as well do this here.
+ */
+ return result + ffz(__swab32(tmp) | (~0UL << size));
+found_middle:
+ return result + ffz(__swab32(tmp));
+}
+
+#else
+# error processor byte order undefined!
+#endif
+
+
+#define hweight32(x) generic_hweight32(x)
+#define hweight16(x) generic_hweight16(x)
+#define hweight8(x) generic_hweight8(x)
+
+/*
+ * Find the first bit set in a 140-bit bitmap.
+ * The first 100 bits are unlikely to be set.
+ */
+
+static inline int sched_find_first_bit(const unsigned long *b)
+{
+ if (unlikely(b[0]))
+ return __ffs(b[0]);
+ if (unlikely(b[1]))
+ return __ffs(b[1]) + 32;
+ if (unlikely(b[2]))
+ return __ffs(b[2]) + 64;
+ if (b[3])
+ return __ffs(b[3]) + 96;
+ return __ffs(b[4]) + 128;
+}
+
+
+/* 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 /* _XTENSA_BITOPS_H */