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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v3 10/34] xen/riscv: introduce bitops.h
Taken from Linux-6.4.0-rc1
Xen's bitops.h consists of several Linux's headers:
* linux/arch/include/asm/bitops.h:
* The following function were removed as they aren't used in Xen:
* test_and_change_bit
* test_and_set_bit_lock
* clear_bit_unlock
* __clear_bit_unlock
* The following functions were renamed in the way how they are
used by common code:
* __test_and_set_bit
* __test_and_clear_bit
* The declaration and implementation of the following functios
were updated to make Xen build happy:
* clear_bit
* set_bit
* __test_and_clear_bit
* __test_and_set_bit
* linux/include/asm-generic/bitops/find.h ( only few function
declaration were taken, as implementation will be provided by
Xen ).
* linux/arch/include/linux/bits.h ( taken only definitions for BIT_MASK,
BIT_WORD, BITS_PER_BYTE )
Additionaly, the following bit ops are introduced:
* __ffs
* ffsl
* fls
* flsl
* ffs
* ffz
* find_first_bit_set
* hweight64
* test_bit
Some of the introduced bit operations are included in asm-generic,
as they exhibit similarity across multiple architectures.
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
---
Changes in V3:
- update the commit message
- Introduce the following asm-generic bitops headers:
create mode 100644 xen/arch/riscv/include/asm/bitops.h
create mode 100644 xen/include/asm-generic/bitops/bitops-bits.h
create mode 100644 xen/include/asm-generic/bitops/ffs.h
create mode 100644 xen/include/asm-generic/bitops/ffz.h
create mode 100644 xen/include/asm-generic/bitops/find-first-bit-set.h
create mode 100644 xen/include/asm-generic/bitops/fls.h
create mode 100644 xen/include/asm-generic/bitops/flsl.h
create mode 100644 xen/include/asm-generic/bitops/hweight.h
create mode 100644 xen/include/asm-generic/bitops/test-bit.h
- switch some bitops functions to asm-generic's versions.
- re-sync some macros with Linux kernel version mentioned in the commit
message.
- Xen code style fixes.
---
Changes in V2:
- Nothing changed. Only rebase.
---
xen/arch/riscv/include/asm/bitops.h | 267 ++++++++++++++++++
xen/include/asm-generic/bitops/bitops-bits.h | 10 +
xen/include/asm-generic/bitops/ffs.h | 9 +
xen/include/asm-generic/bitops/ffz.h | 13 +
.../asm-generic/bitops/find-first-bit-set.h | 17 ++
xen/include/asm-generic/bitops/fls.h | 18 ++
xen/include/asm-generic/bitops/flsl.h | 10 +
xen/include/asm-generic/bitops/hweight.h | 13 +
xen/include/asm-generic/bitops/test-bit.h | 16 ++
9 files changed, 373 insertions(+)
create mode 100644 xen/arch/riscv/include/asm/bitops.h
create mode 100644 xen/include/asm-generic/bitops/bitops-bits.h
create mode 100644 xen/include/asm-generic/bitops/ffs.h
create mode 100644 xen/include/asm-generic/bitops/ffz.h
create mode 100644 xen/include/asm-generic/bitops/find-first-bit-set.h
create mode 100644 xen/include/asm-generic/bitops/fls.h
create mode 100644 xen/include/asm-generic/bitops/flsl.h
create mode 100644 xen/include/asm-generic/bitops/hweight.h
create mode 100644 xen/include/asm-generic/bitops/test-bit.h
diff --git a/xen/arch/riscv/include/asm/bitops.h
b/xen/arch/riscv/include/asm/bitops.h
new file mode 100644
index 0000000000..d210f529c8
--- /dev/null
+++ b/xen/arch/riscv/include/asm/bitops.h
@@ -0,0 +1,267 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2012 Regents of the University of California */
+
+#ifndef _ASM_RISCV_BITOPS_H
+#define _ASM_RISCV_BITOPS_H
+
+#include <asm/system.h>
+
+#include <asm-generic/bitops/bitops-bits.h>
+
+/* Based on linux/arch/include/linux/bits.h */
+
+#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
+#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
+
+#define __set_bit(n,p) set_bit(n,p)
+#define __clear_bit(n,p) clear_bit(n,p)
+
+/* Based on linux/arch/include/asm/bitops.h */
+
+#if ( BITS_PER_LONG == 64 )
+#define __AMO(op) "amo" #op ".d"
+#elif ( BITS_PER_LONG == 32 )
+#define __AMO(op) "amo" #op ".w"
+#else
+#error "Unexpected BITS_PER_LONG"
+#endif
+
+#define __test_and_op_bit_ord(op, mod, nr, addr, ord) \
+({ \
+ unsigned long __res, __mask; \
+ __mask = BIT_MASK(nr); \
+ __asm__ __volatile__ ( \
+ __AMO(op) #ord " %0, %2, %1" \
+ : "=r" (__res), "+A" (addr[BIT_WORD(nr)]) \
+ : "r" (mod(__mask)) \
+ : "memory"); \
+ ((__res & __mask) != 0); \
+})
+
+#define __op_bit_ord(op, mod, nr, addr, ord) \
+ __asm__ __volatile__ ( \
+ __AMO(op) #ord " zero, %1, %0" \
+ : "+A" (addr[BIT_WORD(nr)]) \
+ : "r" (mod(BIT_MASK(nr))) \
+ : "memory");
+
+#define __test_and_op_bit(op, mod, nr, addr) \
+ __test_and_op_bit_ord(op, mod, nr, addr, .aqrl)
+#define __op_bit(op, mod, nr, addr) \
+ __op_bit_ord(op, mod, nr, addr, )
+
+/* Bitmask modifiers */
+#define __NOP(x) (x)
+#define __NOT(x) (~(x))
+
+/**
+ * __test_and_set_bit - Set a bit and return its old value
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation may be reordered on other architectures than x86.
+ */
+static inline int __test_and_set_bit(int nr, volatile void *p)
+{
+ volatile uint32_t *addr = p;
+
+ return __test_and_op_bit(or, __NOP, nr, addr);
+}
+
+/**
+ * __test_and_clear_bit - Clear a bit and return its old value
+ * @nr: Bit to clear
+ * @addr: Address to count from
+ *
+ * This operation can be reordered on other architectures other than x86.
+ */
+static inline int __test_and_clear_bit(int nr, volatile void *p)
+{
+ volatile uint32_t *addr = p;
+
+ return __test_and_op_bit(and, __NOT, nr, addr);
+}
+
+/**
+ * set_bit - Atomically set a bit in memory
+ * @nr: the bit to set
+ * @addr: the address to start counting from
+ *
+ * Note: there are no guarantees that this function will not be reordered
+ * on non x86 architectures, so if you are writing portable code,
+ * make sure not to rely on its reordering guarantees.
+ *
+ * Note that @nr may be almost arbitrarily large; this function is not
+ * restricted to acting on a single-word quantity.
+ */
+static inline void set_bit(int nr, volatile void *p)
+{
+ volatile uint32_t *addr = p;
+
+ __op_bit(or, __NOP, nr, addr);
+}
+
+/**
+ * clear_bit - Clears a bit in memory
+ * @nr: Bit to clear
+ * @addr: Address to start counting from
+ *
+ * Note: there are no guarantees that this function will not be reordered
+ * on non x86 architectures, so if you are writing portable code,
+ * make sure not to rely on its reordering guarantees.
+ */
+static inline void clear_bit(int nr, volatile void *p)
+{
+ volatile uint32_t *addr = p;
+
+ __op_bit(and, __NOT, nr, addr);
+}
+
+#undef __test_and_op_bit
+#undef __op_bit
+#undef __NOP
+#undef __NOT
+#undef __AMO
+
+#define test_and_set_bit __test_and_set_bit
+#define test_and_clear_bit __test_and_clear_bit
+
+/* Based on linux/include/asm-generic/bitops/find.h */
+
+#ifndef find_next_bit
+/**
+ * find_next_bit - find the next set bit in a memory region
+ * @addr: The address to base the search on
+ * @offset: The bitnumber to start searching at
+ * @size: The bitmap size in bits
+ */
+extern unsigned long find_next_bit(const unsigned long *addr, unsigned long
+ size, unsigned long offset);
+#endif
+
+#ifndef find_next_zero_bit
+/**
+ * find_next_zero_bit - find the next cleared bit in a memory region
+ * @addr: The address to base the search on
+ * @offset: The bitnumber to start searching at
+ * @size: The bitmap size in bits
+ */
+extern unsigned long find_next_zero_bit(const unsigned long *addr, unsigned
+ long size, unsigned long offset);
+#endif
+
+/**
+ * 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.
+ */
+extern unsigned long find_first_bit(const unsigned long *addr,
+ unsigned long size);
+
+/**
+ * find_first_zero_bit - find the first cleared 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 cleared bit.
+ */
+extern unsigned long find_first_zero_bit(const unsigned long *addr,
+ unsigned long size);
+
+/**
+ * ffs - find first bit in word.
+ * @word: The word to search
+ *
+ * Returns 0 if no bit exists, otherwise returns 1-indexed bit location.
+ */
+static inline unsigned long __ffs(unsigned long word)
+{
+ int num = 0;
+
+#if BITS_PER_LONG == 64
+ if ((word & 0xffffffff) == 0) {
+ num += 32;
+ word >>= 32;
+ }
+#endif
+ if ((word & 0xffff) == 0) {
+ num += 16;
+ word >>= 16;
+ }
+ if ((word & 0xff) == 0) {
+ num += 8;
+ word >>= 8;
+ }
+ if ((word & 0xf) == 0) {
+ num += 4;
+ word >>= 4;
+ }
+ if ((word & 0x3) == 0) {
+ num += 2;
+ word >>= 2;
+ }
+ if ((word & 0x1) == 0)
+ num += 1;
+ return num;
+}
+
+/**
+ * ffsl - find first bit in long.
+ * @word: The word to search
+ *
+ * Returns 0 if no bit exists, otherwise returns 1-indexed bit location.
+ */
+static inline unsigned int ffsl(unsigned long word)
+{
+ int num = 1;
+
+ if (!word)
+ return 0;
+
+#if BITS_PER_LONG == 64
+ if ((word & 0xffffffff) == 0) {
+ num += 32;
+ word >>= 32;
+ }
+#endif
+ if ((word & 0xffff) == 0) {
+ num += 16;
+ word >>= 16;
+ }
+ if ((word & 0xff) == 0) {
+ num += 8;
+ word >>= 8;
+ }
+ if ((word & 0xf) == 0) {
+ num += 4;
+ word >>= 4;
+ }
+ if ((word & 0x3) == 0) {
+ num += 2;
+ word >>= 2;
+ }
+ if ((word & 0x1) == 0)
+ num += 1;
+ return num;
+}
+
+#include <asm-generic/bitops/fls.h>
+#include <asm-generic/bitops/flsl.h>
+#include <asm-generic/bitops/ffs.h>
+#include <asm-generic/bitops/ffz.h>
+#include <asm-generic/bitops/find-first-bit-set.h>
+#include <asm-generic/bitops/hweight.h>
+#include <asm-generic/bitops/test-bit.h>
+
+#endif /* _ASM_RISCV_BITOPS_H */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/include/asm-generic/bitops/bitops-bits.h
b/xen/include/asm-generic/bitops/bitops-bits.h
new file mode 100644
index 0000000000..8a57e47c63
--- /dev/null
+++ b/xen/include/asm-generic/bitops/bitops-bits.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_BITOPS_BITS_H_
+#define _ASM_GENERIC_BITOPS_BITS_H_
+
+#define BITOP_BITS_PER_WORD 32
+#define BITOP_MASK(nr) (1UL << ((nr) % BITOP_BITS_PER_WORD))
+#define BITOP_WORD(nr) ((nr) / BITOP_BITS_PER_WORD)
+#define BITS_PER_BYTE 8
+
+#endif /* _ASM_GENERIC_BITOPS_BITS_H_ */
\ No newline at end of file
diff --git a/xen/include/asm-generic/bitops/ffs.h
b/xen/include/asm-generic/bitops/ffs.h
new file mode 100644
index 0000000000..3f75fded14
--- /dev/null
+++ b/xen/include/asm-generic/bitops/ffs.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_BITOPS_FFS_H_
+#define _ASM_GENERIC_BITOPS_FFS_H_
+
+#include <xen/macros.h>
+
+#define ffs(x) ({ unsigned int t_ = (x); fls(ISOLATE_LSB(t_)); })
+
+#endif /* _ASM_GENERIC_BITOPS_FFS_H_ */
diff --git a/xen/include/asm-generic/bitops/ffz.h
b/xen/include/asm-generic/bitops/ffz.h
new file mode 100644
index 0000000000..92c35455d5
--- /dev/null
+++ b/xen/include/asm-generic/bitops/ffz.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_BITOPS_FFZ_H_
+#define _ASM_GENERIC_BITOPS_FFZ_H_
+
+/*
+ * ffz - find first zero in word.
+ * @word: The word to search
+ *
+ * Undefined if no zero exists, so code should check against ~0UL first.
+ */
+#define ffz(x) __ffs(~(x))
+
+#endif /* _ASM_GENERIC_BITOPS_FFZ_H_ */
\ No newline at end of file
diff --git a/xen/include/asm-generic/bitops/find-first-bit-set.h
b/xen/include/asm-generic/bitops/find-first-bit-set.h
new file mode 100644
index 0000000000..8ae9751b11
--- /dev/null
+++ b/xen/include/asm-generic/bitops/find-first-bit-set.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_BITOPS_FIND_FIRST_BIT_SET_H_
+#define _ASM_GENERIC_BITOPS_FIND_FIRST_BIT_SET_H_
+
+/**
+ * find_first_set_bit - find the first set bit in @word
+ * @word: the word to search
+ *
+ * Returns the bit-number of the first set bit (first bit being 0).
+ * The input must *not* be zero.
+ */
+static inline unsigned int find_first_set_bit(unsigned long word)
+{
+ return ffsl(word) - 1;
+}
+
+#endif /* _ASM_GENERIC_BITOPS_FIND_FIRST_BIT_SET_H_ */
\ No newline at end of file
diff --git a/xen/include/asm-generic/bitops/fls.h
b/xen/include/asm-generic/bitops/fls.h
new file mode 100644
index 0000000000..f232925080
--- /dev/null
+++ b/xen/include/asm-generic/bitops/fls.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_BITOPS_FLS_H_
+#define _ASM_GENERIC_BITOPS_FLS_H_
+
+/**
+ * fls - find last (most-significant) bit set
+ * @x: the word to search
+ *
+ * This is defined the same way as ffs.
+ * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
+ */
+
+static inline int fls(unsigned int x)
+{
+ return generic_fls(x);
+}
+
+#endif /* _ASM_GENERIC_BITOPS_FLS_H_ */
\ No newline at end of file
diff --git a/xen/include/asm-generic/bitops/flsl.h
b/xen/include/asm-generic/bitops/flsl.h
new file mode 100644
index 0000000000..127221056e
--- /dev/null
+++ b/xen/include/asm-generic/bitops/flsl.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_BITOPS_FLSL_H_
+#define _ASM_GENERIC_BITOPS_FLSL_H_
+
+static inline int flsl(unsigned long x)
+{
+ return generic_flsl(x);
+}
+
+#endif /* _ASM_GENERIC_BITOPS_FLSL_H_ */
\ No newline at end of file
diff --git a/xen/include/asm-generic/bitops/hweight.h
b/xen/include/asm-generic/bitops/hweight.h
new file mode 100644
index 0000000000..0d7577054e
--- /dev/null
+++ b/xen/include/asm-generic/bitops/hweight.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_BITOPS_HWEIGHT_H_
+#define _ASM_GENERIC_BITOPS_HWEIGHT_H_
+
+/*
+ * hweightN - returns the hamming weight of a N-bit word
+ * @x: the word to weigh
+ *
+ * The Hamming Weight of a number is the total number of bits set in it.
+ */
+#define hweight64(x) generic_hweight64(x)
+
+#endif /* _ASM_GENERIC_BITOPS_HWEIGHT_H_ */
diff --git a/xen/include/asm-generic/bitops/test-bit.h
b/xen/include/asm-generic/bitops/test-bit.h
new file mode 100644
index 0000000000..9fa36652e3
--- /dev/null
+++ b/xen/include/asm-generic/bitops/test-bit.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_BITOPS_TESTBIT_H_
+#define _ASM_GENERIC_BITOPS_TESTBIT_H_
+
+/**
+ * test_bit - Determine whether a bit is set
+ * @nr: bit number to test
+ * @addr: Address to start counting from
+ */
+static inline int test_bit(int nr, const volatile void *addr)
+{
+ const volatile unsigned int *p = addr;
+ return 1 & (p[BITOP_WORD(nr)] >> (nr & (BITOP_BITS_PER_WORD - 1)));
+}
+
+#endif /* _ASM_GENERIC_BITOPS_TESTBIT_H_ */
\ No newline at end of file
--
2.43.0
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