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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/microblaze/include/asm/delay.h | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/microblaze/include/asm/delay.h')
-rw-r--r-- | arch/microblaze/include/asm/delay.h | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/arch/microblaze/include/asm/delay.h b/arch/microblaze/include/asm/delay.h new file mode 100644 index 000000000..05fe9e3e0 --- /dev/null +++ b/arch/microblaze/include/asm/delay.h @@ -0,0 +1,85 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2008 Michal Simek + * Copyright (C) 2007 John Williams + * Copyright (C) 2006 Atmark Techno, Inc. + */ + +#ifndef _ASM_MICROBLAZE_DELAY_H +#define _ASM_MICROBLAZE_DELAY_H + +#include <linux/param.h> + +static inline void __delay(unsigned long loops) +{ + asm volatile ("# __delay \n\t" \ + "1: addi %0, %0, -1\t\n" \ + "bneid %0, 1b \t\n" \ + "nop \t\n" + : "=r" (loops) + : "0" (loops)); +} + +/* + * Note that 19 * 226 == 4294 ==~ 2^32 / 10^6, so + * loops = (4294 * usecs * loops_per_jiffy * HZ) / 2^32. + * + * The mul instruction gives us loops = (a * b) / 2^32. + * We choose a = usecs * 19 * HZ and b = loops_per_jiffy * 226 + * because this lets us support a wide range of HZ and + * loops_per_jiffy values without either a or b overflowing 2^32. + * Thus we need usecs * HZ <= (2^32 - 1) / 19 = 226050910 and + * loops_per_jiffy <= (2^32 - 1) / 226 = 19004280 + * (which corresponds to ~3800 bogomips at HZ = 100). + * -- paulus + */ +#define __MAX_UDELAY (226050910UL/HZ) /* maximum udelay argument */ +#define __MAX_NDELAY (4294967295UL/HZ) /* maximum ndelay argument */ + +extern unsigned long loops_per_jiffy; + +static inline void __udelay(unsigned int x) +{ + + unsigned long long tmp = + (unsigned long long)x * (unsigned long long)loops_per_jiffy \ + * 226LL; + unsigned loops = tmp >> 32; + +/* + __asm__("mulxuu %0,%1,%2" : "=r" (loops) : + "r" (x), "r" (loops_per_jiffy * 226)); +*/ + __delay(loops); +} + +extern void __bad_udelay(void); /* deliberately undefined */ +extern void __bad_ndelay(void); /* deliberately undefined */ + +#define udelay(n) \ + ({ \ + if (__builtin_constant_p(n)) { \ + if ((n) / __MAX_UDELAY >= 1) \ + __bad_udelay(); \ + else \ + __udelay((n) * (19 * HZ)); \ + } else { \ + __udelay((n) * (19 * HZ)); \ + } \ + }) + +#define ndelay(n) \ + ({ \ + if (__builtin_constant_p(n)) { \ + if ((n) / __MAX_NDELAY >= 1) \ + __bad_ndelay(); \ + else \ + __udelay((n) * HZ); \ + } else { \ + __udelay((n) * HZ); \ + } \ + }) + +#define muldiv(a, b, c) (((a)*(b))/(c)) + +#endif /* _ASM_MICROBLAZE_DELAY_H */ |