Commit d0735693 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Borislav Petkov
Browse files

x86/mm: Cleanup pgprot_4k_2_large() and pgprot_large_2_4k() 



Make use of lower level helpers that operate on the raw protection
values to make the code a little easier to understand, and to also
avoid extra conversions in a few callers.

[ Qian: Fix a wrongly placed bracket in the original submission.
  Reported and fixed by Qian Cai <cai@lca.pw>. Details in second
  Link: below. ]

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200408152745.1565832-4-hch@lst.de
Link: https://lkml.kernel.org/r/1ED37D02-125F-4919-861A-371981581D9E@lca.pw
parent 7fa3e10f

arch/x86/include/asm/pgtable_types.h

+13 −13
Original line number Diff line number Diff line
@@ -488,24 +488,24 @@ static inline pgprot_t cachemode2pgprot(enum page_cache_mode pcm) 
{

	return __pgprot(cachemode2protval(pcm));

}

static inline pgprot_t pgprot_4k_2_large(pgprot_t pgprot)

static inline unsigned long protval_4k_2_large(unsigned long val)

{

	pgprotval_t val = pgprot_val(pgprot);

	pgprot_t new;



	pgprot_val(new) = (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) |

	return (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) |

		((val & _PAGE_PAT) << (_PAGE_BIT_PAT_LARGE - _PAGE_BIT_PAT));

	return new;

}

static inline pgprot_t pgprot_large_2_4k(pgprot_t pgprot)

static inline pgprot_t pgprot_4k_2_large(pgprot_t pgprot)

{

	pgprotval_t val = pgprot_val(pgprot);

	pgprot_t new;



	pgprot_val(new) = (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) |

	return __pgprot(protval_4k_2_large(pgprot_val(pgprot)));

}

static inline unsigned long protval_large_2_4k(unsigned long val)

{

	return (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) |

		((val & _PAGE_PAT_LARGE) >>

		 (_PAGE_BIT_PAT_LARGE - _PAGE_BIT_PAT));

	return new;

}

static inline pgprot_t pgprot_large_2_4k(pgprot_t pgprot)

{

	return __pgprot(protval_large_2_4k(pgprot_val(pgprot)));

}

arch/x86/mm/init_64.c

+1 −1
Original line number Diff line number Diff line
@@ -367,7 +367,7 @@ static void __init __init_extra_mapping(unsigned long phys, unsigned long size, 
	pgprot_t prot;



	pgprot_val(prot) = pgprot_val(PAGE_KERNEL_LARGE) |

		pgprot_val(pgprot_4k_2_large(cachemode2pgprot(cache)));

		protval_4k_2_large(cachemode2protval(cache));

	BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));

	for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {

		pgd = pgd_offset_k((unsigned long)__va(phys));

arch/x86/mm/pgtable.c

+2 −6
Original line number Diff line number Diff line
@@ -706,11 +706,9 @@ int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot) 
	if (pud_present(*pud) && !pud_huge(*pud))

		return 0;



	prot = pgprot_4k_2_large(prot);



	set_pte((pte_t *)pud, pfn_pte(

		(u64)addr >> PAGE_SHIFT,

		__pgprot(pgprot_val(prot) | _PAGE_PSE)));

		__pgprot(protval_4k_2_large(pgprot_val(prot)) | _PAGE_PSE)));



	return 1;

}
@@ -738,11 +736,9 @@ int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot) 
	if (pmd_present(*pmd) && !pmd_huge(*pmd))

		return 0;



	prot = pgprot_4k_2_large(prot);



	set_pte((pte_t *)pmd, pfn_pte(

		(u64)addr >> PAGE_SHIFT,

		__pgprot(pgprot_val(prot) | _PAGE_PSE)));

		__pgprot(protval_4k_2_large(pgprot_val(prot)) | _PAGE_PSE)));



	return 1;

}

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