From patchwork Mon Jan 20 12:43:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Brodkin X-Patchwork-Id: 239819 List-Id: U-Boot discussion From: Alexey.Brodkin at synopsys.com (Alexey Brodkin) Date: Mon, 20 Jan 2020 15:43:28 +0300 Subject: [RFC 1/2] include: Import non-atomic.h from Linux In-Reply-To: <20200120124329.3001-1-abrodkin@synopsys.com> References: <20200120124329.3001-1-abrodkin@synopsys.com> Message-ID: <20200120124329.3001-2-abrodkin@synopsys.com> This header contains implementations of some common bit ops: * __set_bit()/__clear_bit()/__change_bit()/test_bit() * __test_and_set_bit()/__test_and_clear_bit()/__test_and_change_bit() No point in copy-pasting that again & again. Signed-off-by: Alexey Brodkin --- include/asm-generic/bitops/non-atomic.h | 109 ++++++++++++++++++++++++++++++++ 1 file changed, 109 insertions(+) create mode 100644 include/asm-generic/bitops/non-atomic.h diff --git a/include/asm-generic/bitops/non-atomic.h b/include/asm-generic/bitops/non-atomic.h new file mode 100644 index 0000000000..9b3be37fff --- /dev/null +++ b/include/asm-generic/bitops/non-atomic.h @@ -0,0 +1,109 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ +#define _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ + +#include + +/** + * __set_bit - Set a bit in memory + * @nr: the bit to set + * @addr: the address to start counting from + * + * Unlike set_bit(), this function is non-atomic and may be reordered. + * If it's called on the same region of memory simultaneously, the effect + * may be that only one operation succeeds. + */ +static inline void __set_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + + *p |= mask; +} + +static inline void __clear_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + + *p &= ~mask; +} + +/** + * __change_bit - Toggle a bit in memory + * @nr: the bit to change + * @addr: the address to start counting from + * + * Unlike change_bit(), this function is non-atomic and may be reordered. + * If it's called on the same region of memory simultaneously, the effect + * may be that only one operation succeeds. + */ +static inline void __change_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + + *p ^= mask; +} + +/** + * __test_and_set_bit - Set a bit and return its old value + * @nr: Bit to set + * @addr: Address to count from + * + * This operation is non-atomic and can be reordered. + * If two examples of this operation race, one can appear to succeed + * but actually fail. You must protect multiple accesses with a lock. + */ +static inline int __test_and_set_bit(int nr, volatile unsigned long *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; +} + +/** + * __test_and_clear_bit - Clear a bit and return its old value + * @nr: Bit to clear + * @addr: Address to count from + * + * This operation is non-atomic and can be reordered. + * If two examples of this operation race, one can appear to succeed + * but actually fail. You must protect multiple accesses with a lock. + */ +static inline int __test_and_clear_bit(int nr, volatile unsigned long *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; +} + +/* WARNING: non atomic and it can be reordered! */ +static inline int __test_and_change_bit(int nr, + volatile unsigned long *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; +} + +/** + * 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 unsigned long *addr) +{ + return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG - 1))); +} + +#endif /* _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ */ From patchwork Mon Jan 20 12:43:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Brodkin X-Patchwork-Id: 239820 List-Id: U-Boot discussion From: Alexey.Brodkin at synopsys.com (Alexey Brodkin) Date: Mon, 20 Jan 2020 15:43:29 +0300 Subject: [RFC 2/2] ARC: Add support of bitops via generic implementation In-Reply-To: <20200120124329.3001-1-abrodkin@synopsys.com> References: <20200120124329.3001-1-abrodkin@synopsys.com> Message-ID: <20200120124329.3001-3-abrodkin@synopsys.com> This allows building more things. In particular with CONFIG_PKCS7_MESSAGE_PARSER=y we saw this: ------------------------>8---------------------- lib/crypto/pkcs7_parser.c: In function 'pkcs7_sig_note_authenticated_attr': lib/crypto/pkcs7_parser.c:489:7: warning: implicit declaration of function '__test_and_set_bit' [-Wimplicit-function-declaration] 489 | if (__test_and_set_bit(sinfo_has_content_type, &sinfo->aa_set)) | ^~~~~~~~~~~~~~~~~~ CC lib/crc32.o CC lib/ctype.o DTB test/overlay/test-fdt-overlay-stacked.dtb.S CC lib/div64.o lib/crypto/pkcs7_parser.c: In function 'pkcs7_sig_note_set_of_authattrs': lib/crypto/pkcs7_parser.c:572:7: warning: implicit declaration of function 'test_bit' [-Wimplicit-function-declaration] 572 | if (!test_bit(sinfo_has_content_type, &sinfo->aa_set) || ... LD u-boot arc-elf32-ld.bfd: lib/built-in.o: in function 'pkcs7_sig_note_authenticated_attr': .../lib/crypto/pkcs7_parser.c:489: undefined reference to '__test_and_set_bit' arc-elf32-ld.bfd: .../lib/crypto/pkcs7_parser.c:489: undefined reference to '__test_and_set_bit' arc-elf32-ld.bfd: .../lib/crypto/pkcs7_parser.c:501: undefined reference to '__test_and_set_bit' arc-elf32-ld.bfd: .../lib/crypto/pkcs7_parser.c:501: undefined reference to '__test_and_set_bit' arc-elf32-ld.bfd: .../lib/crypto/pkcs7_parser.c:510: undefined reference to '__test_and_set_bit' arc-elf32-ld.bfd: lib/built-in.o:.../lib/crypto/pkcs7_parser.c:510: more undefined references to '__test_and_set_bit' follow arc-elf32-ld.bfd: lib/built-in.o: in function 'pkcs7_sig_note_set_of_authattrs': .../lib/crypto/pkcs7_parser.c:572: undefined reference to `test_bit' arc-elf32-ld.bfd: .../lib/crypto/pkcs7_parser.c:572: undefined reference to `test_bit' arc-elf32-ld.bfd: .../lib/crypto/pkcs7_parser.c:573: undefined reference to `test_bit' arc-elf32-ld.bfd: .../lib/crypto/pkcs7_parser.c:573: undefined reference to `test_bit' arc-elf32-ld.bfd: .../lib/crypto/pkcs7_parser.c:579: undefined reference to `test_bit' arc-elf32-ld.bfd: lib/built-in.o:.../lib/crypto/pkcs7_parser.c:579: more undefined references to 'test_bit' follow ------------------------>8---------------------- Signed-off-by: Alexey Brodkin --- arch/arc/include/asm/bitops.h | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arc/include/asm/bitops.h b/arch/arc/include/asm/bitops.h index c6dd28ecef..daa07e80a8 100644 --- a/arch/arc/include/asm/bitops.h +++ b/arch/arc/include/asm/bitops.h @@ -19,5 +19,6 @@ #include #include #include +#include #endif /* __ASM_ARC_BITOPS_H */