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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/powerpc/include/asm/bitops.h
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/powerpc/include/asm/bitops.h')
-rw-r--r--arch/powerpc/include/asm/bitops.h346
1 files changed, 346 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/bitops.h b/arch/powerpc/include/asm/bitops.h
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+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * PowerPC atomic bit operations.
+ *
+ * Merged version by David Gibson <david@gibson.dropbear.id.au>.
+ * Based on ppc64 versions by: Dave Engebretsen, Todd Inglett, Don
+ * Reed, Pat McCarthy, Peter Bergner, Anton Blanchard. They
+ * originally took it from the ppc32 code.
+ *
+ * Within a word, bits are numbered LSB first. Lot's of places make
+ * this assumption by directly testing bits with (val & (1<<nr)).
+ * This can cause confusion for large (> 1 word) bitmaps on a
+ * big-endian system because, unlike little endian, the number of each
+ * bit depends on the word size.
+ *
+ * The bitop functions are defined to work on unsigned longs, so for a
+ * ppc64 system the bits end up numbered:
+ * |63..............0|127............64|191...........128|255...........192|
+ * and on ppc32:
+ * |31.....0|63....32|95....64|127...96|159..128|191..160|223..192|255..224|
+ *
+ * There are a few little-endian macros used mostly for filesystem
+ * bitmaps, these work on similar bit arrays layouts, but
+ * byte-oriented:
+ * |7...0|15...8|23...16|31...24|39...32|47...40|55...48|63...56|
+ *
+ * The main difference is that bit 3-5 (64b) or 3-4 (32b) in the bit
+ * number field needs to be reversed compared to the big-endian bit
+ * fields. This can be achieved by XOR with 0x38 (64b) or 0x18 (32b).
+ */
+
+#ifndef _ASM_POWERPC_BITOPS_H
+#define _ASM_POWERPC_BITOPS_H
+
+#ifdef __KERNEL__
+
+#ifndef _LINUX_BITOPS_H
+#error only <linux/bitops.h> can be included directly
+#endif
+
+#include <linux/compiler.h>
+#include <asm/asm-compat.h>
+#include <asm/synch.h>
+
+/* PPC bit number conversion */
+#define PPC_BITLSHIFT(be) (BITS_PER_LONG - 1 - (be))
+#define PPC_BIT(bit) (1UL << PPC_BITLSHIFT(bit))
+#define PPC_BITMASK(bs, be) ((PPC_BIT(bs) - PPC_BIT(be)) | PPC_BIT(bs))
+
+/* Put a PPC bit into a "normal" bit position */
+#define PPC_BITEXTRACT(bits, ppc_bit, dst_bit) \
+ ((((bits) >> PPC_BITLSHIFT(ppc_bit)) & 1) << (dst_bit))
+
+#define PPC_BITLSHIFT32(be) (32 - 1 - (be))
+#define PPC_BIT32(bit) (1UL << PPC_BITLSHIFT32(bit))
+#define PPC_BITMASK32(bs, be) ((PPC_BIT32(bs) - PPC_BIT32(be))|PPC_BIT32(bs))
+
+#define PPC_BITLSHIFT8(be) (8 - 1 - (be))
+#define PPC_BIT8(bit) (1UL << PPC_BITLSHIFT8(bit))
+#define PPC_BITMASK8(bs, be) ((PPC_BIT8(bs) - PPC_BIT8(be))|PPC_BIT8(bs))
+
+#include <asm/barrier.h>
+
+/* Macro for generating the ***_bits() functions */
+#define DEFINE_BITOP(fn, op, prefix) \
+static inline void fn(unsigned long mask, \
+ volatile unsigned long *_p) \
+{ \
+ unsigned long old; \
+ unsigned long *p = (unsigned long *)_p; \
+ __asm__ __volatile__ ( \
+ prefix \
+"1:" PPC_LLARX "%0,0,%3,0\n" \
+ #op "%I2 %0,%0,%2\n" \
+ PPC_STLCX "%0,0,%3\n" \
+ "bne- 1b\n" \
+ : "=&r" (old), "+m" (*p) \
+ : "rK" (mask), "r" (p) \
+ : "cc", "memory"); \
+}
+
+DEFINE_BITOP(set_bits, or, "")
+DEFINE_BITOP(change_bits, xor, "")
+
+static __always_inline bool is_rlwinm_mask_valid(unsigned long x)
+{
+ if (!x)
+ return false;
+ if (x & 1)
+ x = ~x; // make the mask non-wrapping
+ x += x & -x; // adding the low set bit results in at most one bit set
+
+ return !(x & (x - 1));
+}
+
+#define DEFINE_CLROP(fn, prefix) \
+static inline void fn(unsigned long mask, volatile unsigned long *_p) \
+{ \
+ unsigned long old; \
+ unsigned long *p = (unsigned long *)_p; \
+ \
+ if (IS_ENABLED(CONFIG_PPC32) && \
+ __builtin_constant_p(mask) && is_rlwinm_mask_valid(~mask)) {\
+ asm volatile ( \
+ prefix \
+ "1:" "lwarx %0,0,%3\n" \
+ "rlwinm %0,%0,0,%2\n" \
+ "stwcx. %0,0,%3\n" \
+ "bne- 1b\n" \
+ : "=&r" (old), "+m" (*p) \
+ : "n" (~mask), "r" (p) \
+ : "cc", "memory"); \
+ } else { \
+ asm volatile ( \
+ prefix \
+ "1:" PPC_LLARX "%0,0,%3,0\n" \
+ "andc %0,%0,%2\n" \
+ PPC_STLCX "%0,0,%3\n" \
+ "bne- 1b\n" \
+ : "=&r" (old), "+m" (*p) \
+ : "r" (mask), "r" (p) \
+ : "cc", "memory"); \
+ } \
+}
+
+DEFINE_CLROP(clear_bits, "")
+DEFINE_CLROP(clear_bits_unlock, PPC_RELEASE_BARRIER)
+
+static inline void arch_set_bit(int nr, volatile unsigned long *addr)
+{
+ set_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
+}
+
+static inline void arch_clear_bit(int nr, volatile unsigned long *addr)
+{
+ clear_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
+}
+
+static inline void arch_clear_bit_unlock(int nr, volatile unsigned long *addr)
+{
+ clear_bits_unlock(BIT_MASK(nr), addr + BIT_WORD(nr));
+}
+
+static inline void arch_change_bit(int nr, volatile unsigned long *addr)
+{
+ change_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
+}
+
+/* Like DEFINE_BITOP(), with changes to the arguments to 'op' and the output
+ * operands. */
+#define DEFINE_TESTOP(fn, op, prefix, postfix, eh) \
+static inline unsigned long fn( \
+ unsigned long mask, \
+ volatile unsigned long *_p) \
+{ \
+ unsigned long old, t; \
+ unsigned long *p = (unsigned long *)_p; \
+ __asm__ __volatile__ ( \
+ prefix \
+"1:" PPC_LLARX "%0,0,%3,%4\n" \
+ #op "%I2 %1,%0,%2\n" \
+ PPC_STLCX "%1,0,%3\n" \
+ "bne- 1b\n" \
+ postfix \
+ : "=&r" (old), "=&r" (t) \
+ : "rK" (mask), "r" (p), "n" (eh) \
+ : "cc", "memory"); \
+ return (old & mask); \
+}
+
+DEFINE_TESTOP(test_and_set_bits, or, PPC_ATOMIC_ENTRY_BARRIER,
+ PPC_ATOMIC_EXIT_BARRIER, 0)
+DEFINE_TESTOP(test_and_set_bits_lock, or, "",
+ PPC_ACQUIRE_BARRIER, IS_ENABLED(CONFIG_PPC64))
+DEFINE_TESTOP(test_and_change_bits, xor, PPC_ATOMIC_ENTRY_BARRIER,
+ PPC_ATOMIC_EXIT_BARRIER, 0)
+
+static inline unsigned long test_and_clear_bits(unsigned long mask, volatile unsigned long *_p)
+{
+ unsigned long old, t;
+ unsigned long *p = (unsigned long *)_p;
+
+ if (IS_ENABLED(CONFIG_PPC32) &&
+ __builtin_constant_p(mask) && is_rlwinm_mask_valid(~mask)) {
+ asm volatile (
+ PPC_ATOMIC_ENTRY_BARRIER
+ "1:" "lwarx %0,0,%3\n"
+ "rlwinm %1,%0,0,%2\n"
+ "stwcx. %1,0,%3\n"
+ "bne- 1b\n"
+ PPC_ATOMIC_EXIT_BARRIER
+ : "=&r" (old), "=&r" (t)
+ : "n" (~mask), "r" (p)
+ : "cc", "memory");
+ } else {
+ asm volatile (
+ PPC_ATOMIC_ENTRY_BARRIER
+ "1:" PPC_LLARX "%0,0,%3,0\n"
+ "andc %1,%0,%2\n"
+ PPC_STLCX "%1,0,%3\n"
+ "bne- 1b\n"
+ PPC_ATOMIC_EXIT_BARRIER
+ : "=&r" (old), "=&r" (t)
+ : "r" (mask), "r" (p)
+ : "cc", "memory");
+ }
+
+ return (old & mask);
+}
+
+static inline int arch_test_and_set_bit(unsigned long nr,
+ volatile unsigned long *addr)
+{
+ return test_and_set_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
+}
+
+static inline int arch_test_and_set_bit_lock(unsigned long nr,
+ volatile unsigned long *addr)
+{
+ return test_and_set_bits_lock(BIT_MASK(nr),
+ addr + BIT_WORD(nr)) != 0;
+}
+
+static inline int arch_test_and_clear_bit(unsigned long nr,
+ volatile unsigned long *addr)
+{
+ return test_and_clear_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
+}
+
+static inline int arch_test_and_change_bit(unsigned long nr,
+ volatile unsigned long *addr)
+{
+ return test_and_change_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
+}
+
+#ifdef CONFIG_PPC64
+static inline unsigned long
+clear_bit_unlock_return_word(int nr, volatile unsigned long *addr)
+{
+ unsigned long old, t;
+ unsigned long *p = (unsigned long *)addr + BIT_WORD(nr);
+ unsigned long mask = BIT_MASK(nr);
+
+ __asm__ __volatile__ (
+ PPC_RELEASE_BARRIER
+"1:" PPC_LLARX "%0,0,%3,0\n"
+ "andc %1,%0,%2\n"
+ PPC_STLCX "%1,0,%3\n"
+ "bne- 1b\n"
+ : "=&r" (old), "=&r" (t)
+ : "r" (mask), "r" (p)
+ : "cc", "memory");
+
+ return old;
+}
+
+/*
+ * This is a special function for mm/filemap.c
+ * Bit 7 corresponds to PG_waiters.
+ */
+#define arch_clear_bit_unlock_is_negative_byte(nr, addr) \
+ (clear_bit_unlock_return_word(nr, addr) & BIT_MASK(7))
+
+#endif /* CONFIG_PPC64 */
+
+#include <asm-generic/bitops/non-atomic.h>
+
+static inline void arch___clear_bit_unlock(int nr, volatile unsigned long *addr)
+{
+ __asm__ __volatile__(PPC_RELEASE_BARRIER "" ::: "memory");
+ __clear_bit(nr, addr);
+}
+
+/*
+ * Return the zero-based bit position (LE, not IBM bit numbering) of
+ * the most significant 1-bit in a double word.
+ */
+#define __ilog2(x) ilog2(x)
+
+#include <asm-generic/bitops/ffz.h>
+
+#include <asm-generic/bitops/builtin-__ffs.h>
+
+#include <asm-generic/bitops/builtin-ffs.h>
+
+/*
+ * fls: find last (most-significant) bit set.
+ * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
+ */
+static __always_inline int fls(unsigned int x)
+{
+ int lz;
+
+ if (__builtin_constant_p(x))
+ return x ? 32 - __builtin_clz(x) : 0;
+ asm("cntlzw %0,%1" : "=r" (lz) : "r" (x));
+ return 32 - lz;
+}
+
+#include <asm-generic/bitops/builtin-__fls.h>
+
+/*
+ * 64-bit can do this using one cntlzd (count leading zeroes doubleword)
+ * instruction; for 32-bit we use the generic version, which does two
+ * 32-bit fls calls.
+ */
+#ifdef CONFIG_PPC64
+static __always_inline int fls64(__u64 x)
+{
+ int lz;
+
+ if (__builtin_constant_p(x))
+ return x ? 64 - __builtin_clzll(x) : 0;
+ asm("cntlzd %0,%1" : "=r" (lz) : "r" (x));
+ return 64 - lz;
+}
+#else
+#include <asm-generic/bitops/fls64.h>
+#endif
+
+#ifdef CONFIG_PPC64
+unsigned int __arch_hweight8(unsigned int w);
+unsigned int __arch_hweight16(unsigned int w);
+unsigned int __arch_hweight32(unsigned int w);
+unsigned long __arch_hweight64(__u64 w);
+#include <asm-generic/bitops/const_hweight.h>
+#else
+#include <asm-generic/bitops/hweight.h>
+#endif
+
+/* wrappers that deal with KASAN instrumentation */
+#include <asm-generic/bitops/instrumented-atomic.h>
+#include <asm-generic/bitops/instrumented-lock.h>
+
+/* Little-endian versions */
+#include <asm-generic/bitops/le.h>
+
+/* Bitmap functions for the ext2 filesystem */
+
+#include <asm-generic/bitops/ext2-atomic-setbit.h>
+
+#include <asm-generic/bitops/sched.h>
+
+#endif /* __KERNEL__ */
+
+#endif /* _ASM_POWERPC_BITOPS_H */