Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) /* SPDX-License-Identifier: GPL-2.0-only */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) #include <linux/linkage.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) #include <asm/percpu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) .text
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  * Inputs:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  * %rsi : memory location to compare
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)  * %rax : low 64 bits of old value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)  * %rdx : high 64 bits of old value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)  * %rbx : low 64 bits of new value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)  * %rcx : high 64 bits of new value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)  * %al  : Operation successful
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) SYM_FUNC_START(this_cpu_cmpxchg16b_emu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) # Emulate 'cmpxchg16b %gs:(%rsi)' except we return the result in %al not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) # via the ZF.  Caller will access %al to get result.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) # Note that this is only useful for a cpuops operation.  Meaning that we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) # do *not* have a fully atomic operation but just an operation that is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) # *atomic* on a single cpu (as provided by the this_cpu_xx class of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) # macros).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	pushfq
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	cli
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	cmpq PER_CPU_VAR((%rsi)), %rax
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 	jne .Lnot_same
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 	cmpq PER_CPU_VAR(8(%rsi)), %rdx
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	jne .Lnot_same
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 	movq %rbx, PER_CPU_VAR((%rsi))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 	movq %rcx, PER_CPU_VAR(8(%rsi))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	popfq
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	mov $1, %al
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	ret
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) .Lnot_same:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 	popfq
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 	xor %al,%al
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 	ret
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) SYM_FUNC_END(this_cpu_cmpxchg16b_emu)