Put the bits in place for Alpha support for ext2. Not tested.

3 files changed, 259 insertions, 0 deletions

diff --git a/sys/gnu/ext2fs/alpha-bitops.h b/sys/gnu/ext2fs/alpha-bitops.h
new file mode 100644
index 0000000..3910da8
--- /dev/null
+++ b/sys/gnu/ext2fs/alpha-bitops.h
@@ -0,0 +1,255 @@
+/* $FreeBSD$ */
+#ifndef _ALPHA_BITOPS_H
+#define _ALPHA_BITOPS_H
+
+/*
+ * Copyright 1994, Linus Torvalds.
+ */
+
+/*
+ * These have to be done with inline assembly: that way the bit-setting
+ * is guaranteed to be atomic. All bit operations return 0 if the bit
+ * was cleared before the operation and != 0 if it was not.
+ *
+ * To get proper branch prediction for the main line, we must branch
+ * forward to code at the end of this object's .text section, then
+ * branch back to restart the operation.
+ *
+ * bit 0 is the LSB of addr; bit 64 is the LSB of (addr+1).
+ */
+static __inline unsigned int set_bit(unsigned long, volatile void *);
+static __inline unsigned int clear_bit(unsigned long, volatile void *);
+static __inline unsigned int change_bit(unsigned long, volatile void *);
+static __inline unsigned int test_bit(int, volatile void *);
+static __inline unsigned long ffz_b(unsigned long x);
+static __inline unsigned long ffz(unsigned long);
+/* static __inline int ffs(int); */
+static __inline void * memscan(void *, int, size_t);
+#ifdef __alpha_cix__
+static __inline unsigned long hweight64(unsigned long);
+#endif
+static __inline unsigned long
+find_next_zero_bit(void *, unsigned long, unsigned long);
+
+static __inline unsigned int set_bit(unsigned long nr, volatile void * addr)
+{
+	unsigned long oldbit;
+	unsigned long temp;
+	volatile unsigned int *m = ((volatile unsigned int *) addr) + (nr >> 5);
+
+	__asm__ __volatile__(
+	"1:	ldl_l %0,%1\n"
+	"	and %0,%3,%2\n"
+	"	bne %2,2f\n"
+	"	xor %0,%3,%0\n"
+	"	stl_c %0,%1\n"
+	"	beq %0,3f\n"
+	"2:\n"
+	".section .text2,\"ax\"\n"
+	"3:	br 1b\n"
+	".previous"
+	:"=&r" (temp), "=m" (*m), "=&r" (oldbit)
+	:"Ir" (1UL << (nr & 31)), "m" (*m));
+	return oldbit;
+}
+
+static __inline unsigned int clear_bit(unsigned long nr, volatile void * addr)
+{
+	unsigned long oldbit;
+	unsigned long temp;
+	volatile unsigned int *m = ((volatile unsigned int *) addr) + (nr >> 5);
+
+	__asm__ __volatile__(
+	"1:	ldl_l %0,%1\n"
+	"	and %0,%3,%2\n"
+	"	beq %2,2f\n"
+	"	xor %0,%3,%0\n"
+	"	stl_c %0,%1\n"
+	"	beq %0,3f\n"
+	"2:\n"
+	".section .text2,\"ax\"\n"
+	"3:	br 1b\n"
+	".previous"
+	:"=&r" (temp), "=m" (*m), "=&r" (oldbit)
+	:"Ir" (1UL << (nr & 31)), "m" (*m));
+	return oldbit;
+}
+
+static __inline unsigned int change_bit(unsigned long nr, volatile void * addr)
+{
+	unsigned long oldbit;
+	unsigned long temp;
+	volatile unsigned int *m = ((volatile unsigned int *) addr) + (nr >> 5);
+
+	__asm__ __volatile__(
+	"1:	ldl_l %0,%1\n"
+	"	xor %0,%2,%0\n"
+	"	stl_c %0,%1\n"
+	"	beq %0,3f\n"
+	".section .text2,\"ax\"\n"
+	"3:	br 1b\n"
+	".previous"
+	:"=&r" (temp), "=m" (*m), "=&r" (oldbit)
+	:"Ir" (1UL << (nr & 31)), "m" (*m));
+	return oldbit;
+}
+
+static __inline unsigned int test_bit(int nr, volatile void * addr)
+{
+	return 1UL & (((volatile int *) addr)[nr >> 5] >> (nr & 31));
+}
+
+/*
+ * ffz = Find First Zero in word. Undefined if no zero exists,
+ * so code should check against ~0UL first..
+ *
+ * Do a binary search on the bits.  Due to the nature of large
+ * constants on the alpha, it is worthwhile to split the search.
+ */
+static __inline unsigned long ffz_b(unsigned long x)
+{
+	unsigned long sum = 0;
+
+	x = ~x & -~x;		/* set first 0 bit, clear others */
+	if (x & 0xF0) sum += 4;
+	if (x & 0xCC) sum += 2;
+	if (x & 0xAA) sum += 1;
+
+	return sum;
+}
+
+static __inline unsigned long ffz(unsigned long word)
+{
+#ifdef __alpha_cix__
+	/* Whee.  EV6 can calculate it directly.  */
+	unsigned long result;
+	__asm__("ctlz %1,%0" : "=r"(result) : "r"(~word));
+	return result;
+#else
+	unsigned long bits, qofs, bofs;
+
+	__asm__("cmpbge %1,%2,%0" : "=r"(bits) : "r"(word), "r"(~0UL));
+	qofs = ffz_b(bits);
+	__asm__("extbl %1,%2,%0" : "=r"(bits) : "r"(word), "r"(qofs));
+	bofs = ffz_b(bits);
+
+	return qofs*8 + bofs;
+#endif
+}
+
+#ifdef __KERNEL__
+#if	0
+/*
+ * ffs: find first bit set. 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(int word)
+{
+	int result = ffz(~word);
+	return word ? result+1 : 0;
+}
+#endif
+
+/*
+ * hweightN: returns the hamming weight (i.e. the number
+ * of bits set) of a N-bit word
+ */
+
+#ifdef __alpha_cix__
+/* Whee.  EV6 can calculate it directly.  */
+static __inline unsigned long hweight64(unsigned long w)
+{
+	unsigned long result;
+	__asm__("ctpop %1,%0" : "=r"(result) : "r"(w));
+	return result;
+}
+
+#define hweight32(x) hweight64((x) & 0xfffffffful)
+#define hweight16(x) hweight64((x) & 0xfffful)
+#define hweight8(x)  hweight64((x) & 0xfful)
+#else
+#define hweight32(x) generic_hweight32(x)
+#define hweight16(x) generic_hweight16(x)
+#define hweight8(x)  generic_hweight8(x)
+#endif
+
+#endif /* __alpha_cix__ */
+
+/* from lib/string.c */
+static __inline void * memscan(void * addr, int c, size_t size)
+{
+	unsigned char * p = (unsigned char *) addr;
+
+	while (size) {
+		if (*p == c)
+			return (void *) p;
+		p++;
+		size--;
+	}
+  	return (void *) p;
+}
+
+
+/*
+ * Find next zero bit in a bitmap reasonably efficiently..
+ */
+static __inline unsigned long find_next_zero_bit(void * addr, unsigned long size, unsigned long offset)
+{
+	unsigned long * p = ((unsigned long *) addr) + (offset >> 6);
+	unsigned long result = offset & ~63UL;
+	unsigned long tmp;
+
+	if (offset >= size)
+		return size;
+	size -= result;
+	offset &= 63UL;
+	if (offset) {
+		tmp = *(p++);
+		tmp |= ~0UL >> (64-offset);
+		if (size < 64)
+			goto found_first;
+		if (~tmp)
+			goto found_middle;
+		size -= 64;
+		result += 64;
+	}
+	while (size & ~63UL) {
+		if (~(tmp = *(p++)))
+			goto found_middle;
+		result += 64;
+		size -= 64;
+	}
+	if (!size)
+		return result;
+	tmp = *p;
+found_first:
+	tmp |= ~0UL << size;
+found_middle:
+	return result + ffz(tmp);
+}
+
+/*
+ * The optimizer actually does good code for this case..
+ */
+#define find_first_zero_bit(addr, size) \
+	find_next_zero_bit((addr), (size), 0)
+
+#ifdef __KERNEL__
+
+#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_set_bit(nr,addr) test_and_set_bit(nr,addr)
+#define minix_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 /* _ALPHA_BITOPS_H */
diff --git a/sys/gnu/ext2fs/ext2_linux_balloc.c b/sys/gnu/ext2fs/ext2_linux_balloc.c
index bc5f08d..fc72311 100644
--- a/sys/gnu/ext2fs/ext2_linux_balloc.c
+++ b/sys/gnu/ext2fs/ext2_linux_balloc.c
@@ -45,6 +45,8 @@
 
 #ifdef __i386__
 #include <gnu/ext2fs/i386-bitops.h>
+#elif __alpha__
+#include <gnu/ext2fs/alpha-bitops.h>
 #else
 #error Provide an bitops.h file, please !
 #endif
diff --git a/sys/gnu/ext2fs/ext2_linux_ialloc.c b/sys/gnu/ext2fs/ext2_linux_ialloc.c
index 3ba49b0..01ae55b 100644
--- a/sys/gnu/ext2fs/ext2_linux_ialloc.c
+++ b/sys/gnu/ext2fs/ext2_linux_ialloc.c
@@ -48,6 +48,8 @@
 
 #ifdef __i386__
 #include <gnu/ext2fs/i386-bitops.h>
+#elif  __alpha__
+#include <gnu/ext2fs/alpha-bitops.h>
 #else
 #error please provide bit operation functions
 #endif