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#include <asm/processor.h>
/*
* __force_order is used by special_insns.h asm code to force instruction
* serialization.
*
* It is not referenced from the code, but GCC < 5 with -fPIE would fail
* due to an undefined symbol. Define it to make these ancient GCCs work.
*/
unsigned long __force_order;
int l5_paging_required(void)
{
/* Check if leaf 7 is supported. */
if (native_cpuid_eax(0) < 7)
return 0;
/* Check if la57 is supported. */
if (!(native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31))))
return 0;
/* Check if 5-level paging has already been enabled. */
if (native_read_cr4() & X86_CR4_LA57)
return 0;
return 1;
}
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