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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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372fddf709
This kernel parameter allows to force kernel to use 4-level paging even if hardware and kernel support 5-level paging. The option may be useful to work around regressions related to 5-level paging. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180518103528.59260-5-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
35 lines
826 B
C
35 lines
826 B
C
// SPDX-License-Identifier: GPL-2.0
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#include "misc.h"
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#if CONFIG_EARLY_PRINTK || CONFIG_RANDOMIZE_BASE || CONFIG_X86_5LEVEL
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static unsigned long fs;
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static inline void set_fs(unsigned long seg)
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{
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fs = seg << 4; /* shift it back */
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}
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typedef unsigned long addr_t;
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static inline char rdfs8(addr_t addr)
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{
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return *((char *)(fs + addr));
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}
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#include "../cmdline.c"
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unsigned long get_cmd_line_ptr(void)
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{
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unsigned long cmd_line_ptr = boot_params->hdr.cmd_line_ptr;
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cmd_line_ptr |= (u64)boot_params->ext_cmd_line_ptr << 32;
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return cmd_line_ptr;
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}
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int cmdline_find_option(const char *option, char *buffer, int bufsize)
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{
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return __cmdline_find_option(get_cmd_line_ptr(), option, buffer, bufsize);
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}
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int cmdline_find_option_bool(const char *option)
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{
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return __cmdline_find_option_bool(get_cmd_line_ptr(), option);
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}
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#endif
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