154fcf3a78
To clean up the per CPU insanity of UP which causes sparse to be rightfully unhappy and prevents the usage of the generic per CPU accessors on cpu_info it is necessary to include <linux/percpu.h> into <asm/msr.h>. Including <linux/percpu.h> into <asm/msr.h> is impossible because it ends up in header dependency hell. The problem is that <asm/processor.h> includes <asm/msr.h>. The inclusion of <linux/percpu.h> results in a compile fail where the compiler cannot longer handle an include in <asm/cpufeature.h> which references boot_cpu_data which is defined in <asm/processor.h>. The only reason why <asm/msr.h> is included in <asm/processor.h> are the set/get_debugctlmsr() inlines. They are defined there because <asm/processor.h> is such a nice dump ground for everything. In fact they belong obviously into <asm/debugreg.h>. Move them to <asm/debugreg.h> and fix up the resulting damage which is just exposing the reliance on random include chains. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240304005104.454678686@linutronix.de
62 lines
1.3 KiB
C
62 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* x86 FPU bug checks:
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*/
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#include <linux/printk.h>
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#include <asm/cpufeature.h>
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#include <asm/fpu/api.h>
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/*
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* Boot time CPU/FPU FDIV bug detection code:
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*/
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static double __initdata x = 4195835.0;
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static double __initdata y = 3145727.0;
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/*
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* This used to check for exceptions..
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* However, it turns out that to support that,
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* the XMM trap handlers basically had to
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* be buggy. So let's have a correct XMM trap
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* handler, and forget about printing out
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* some status at boot.
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*
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* We should really only care about bugs here
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* anyway. Not features.
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*/
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void __init fpu__init_check_bugs(void)
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{
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s32 fdiv_bug;
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/* kernel_fpu_begin/end() relies on patched alternative instructions. */
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if (!boot_cpu_has(X86_FEATURE_FPU))
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return;
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kernel_fpu_begin();
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/*
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* trap_init() enabled FXSR and company _before_ testing for FP
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* problems here.
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*
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* Test for the divl bug: http://en.wikipedia.org/wiki/Fdiv_bug
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*/
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__asm__("fninit\n\t"
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"fldl %1\n\t"
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"fdivl %2\n\t"
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"fmull %2\n\t"
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"fldl %1\n\t"
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"fsubp %%st,%%st(1)\n\t"
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"fistpl %0\n\t"
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"fwait\n\t"
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"fninit"
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: "=m" (*&fdiv_bug)
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: "m" (*&x), "m" (*&y));
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kernel_fpu_end();
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if (fdiv_bug) {
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set_cpu_bug(&boot_cpu_data, X86_BUG_FDIV);
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pr_warn("Hmm, FPU with FDIV bug\n");
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}
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}
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