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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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0707ad30d1
This commit is primarily changes caused by reviewing "sparse" and "checkpatch" output on our sources, so is somewhat noisy, since things like "printk() -> pr_err()" (or whatever) throughout the codebase tend to get tedious to read. Rather than trying to tease apart precisely which things changed due to which type of code review, this commit includes various cleanups in the code: - sparse: Add declarations in headers for globals. - sparse: Fix __user annotations. - sparse: Using gfp_t consistently instead of int. - sparse: removing functions not actually used. - checkpatch: Clean up printk() warnings by using pr_info(), etc.; also avoid partial-line printks except in bootup code. - checkpatch: Use exposed structs rather than typedefs. - checkpatch: Change some C99 comments to C89 comments. In addition, a couple of minor other changes are rolled in to this commit: - Add support for a "raise" instruction to cause SIGFPE, etc., to be raised. - Remove some compat code that is unnecessary when we fully eliminate some of the deprecated syscalls from the generic syscall ABI. - Update the tile_defconfig to reflect current config contents. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
65 lines
1.7 KiB
C
65 lines
1.7 KiB
C
/*
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* Copyright 2010 Tilera Corporation. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for
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* more details.
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* This file is included into spinlock_32.c or _64.c.
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*/
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/*
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* The mfspr in __spinlock_relax() is 5 or 6 cycles plus 2 for loop
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* overhead.
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*/
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#ifdef __tilegx__
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#define CYCLES_PER_RELAX_LOOP 7
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#else
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#define CYCLES_PER_RELAX_LOOP 8
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#endif
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/*
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* Idle the core for CYCLES_PER_RELAX_LOOP * iterations cycles.
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*/
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static inline void
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relax(int iterations)
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{
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for (/*above*/; iterations > 0; iterations--)
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__insn_mfspr(SPR_PASS);
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barrier();
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}
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/* Perform bounded exponential backoff.*/
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static void delay_backoff(int iterations)
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{
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u32 exponent, loops;
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/*
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* 2^exponent is how many times we go around the loop,
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* which takes 8 cycles. We want to start with a 16- to 31-cycle
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* loop, so we need to go around minimum 2 = 2^1 times, so we
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* bias the original value up by 1.
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*/
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exponent = iterations + 1;
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/*
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* Don't allow exponent to exceed 7, so we have 128 loops,
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* or 1,024 (to 2,047) cycles, as our maximum.
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*/
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if (exponent > 8)
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exponent = 8;
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loops = 1 << exponent;
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/* Add a randomness factor so two cpus never get in lock step. */
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loops += __insn_crc32_32(stack_pointer, get_cycles_low()) &
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(loops - 1);
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relax(1 << exponent);
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}
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