Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) /* SPDX-License-Identifier: GPL-2.0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) #ifndef _ASM_HASH_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) #define _ASM_HASH_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  * The later H8SX models have a 32x32-bit multiply, but the H8/300H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  * and H8S have only 16x16->32.  Since it's tolerably compact, this is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  * basically an inlined version of the __mulsi3 code.  Since the inputs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  * are not expected to be small, it's also simplfied by skipping the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)  * early-out checks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)  * (Since neither CPU has any multi-bit shift instructions, a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)  * shift-and-add version is a non-starter.)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)  * TODO: come up with an arch-specific version of the hashing in fs/namei.c,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)  * since that is heavily dependent on rotates.  Which, as mentioned, suck
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)  * horribly on H8.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #if defined(CONFIG_CPU_H300H) || defined(CONFIG_CPU_H8S)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #define HAVE_ARCH__HASH_32 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)  * Multiply by k = 0x61C88647.  Fitting this into three registers requires
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)  * one extra instruction, but reducing register pressure will probably
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)  * make that back and then some.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)  * GCC asm note: %e1 is the high half of operand %1, while %f1 is the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)  * low half.  So if %1 is er4, then %e1 is e4 and %f1 is r4.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)  * This has been designed to modify x in place, since that's the most
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)  * common usage, but preserve k, since hash_64() makes two calls in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)  * quick succession.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) static inline u32 __attribute_const__ __hash_32(u32 x)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	u32 temp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	asm(   "mov.w	%e1,%f0"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 	"\n	mulxu.w	%f2,%0"		/* klow * xhigh */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 	"\n	mov.w	%f0,%e1"	/* The extra instruction */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 	"\n	mov.w	%f1,%f0"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 	"\n	mulxu.w	%e2,%0"		/* khigh * xlow */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 	"\n	add.w	%e1,%f0"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	"\n	mulxu.w	%f2,%1"		/* klow * xlow */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 	"\n	add.w	%f0,%e1"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 	: "=&r" (temp), "=r" (x)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 	: "%r" (GOLDEN_RATIO_32), "1" (x));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 	return x;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) #endif /* _ASM_HASH_H */