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Commit 5b9593f3 authored by Lars Persson's avatar Lars Persson Committed by Ralf Baechle
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Revert "MIPS: Remove race window in page fault handling" 



Revert commit 2a4a8b1e ("MIPS: Remove race window in page fault
handling") because it increased the number of flushed dcache pages and
became a performance problem for some workloads.

Signed-off-by: default avatarLars Persson <larper@axis.com>
Cc: linux-mips@linux-mips.org
Cc: paul.burton@imgtec.com
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9345/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 9a49899e

arch/mips/include/asm/pgtable.h

+5 −4
Original line number Diff line number Diff line
@@ -127,10 +127,6 @@ do { \ 
	}								\

} while(0)





extern void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,

	pte_t pteval);



#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)



#define pte_none(pte)		(!(((pte).pte_high) & ~_PAGE_GLOBAL))
@@ -152,6 +148,7 @@ static inline void set_pte(pte_t *ptep, pte_t pte) 
			buddy->pte_high |= _PAGE_GLOBAL;

	}

}

#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)



static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)

{
@@ -190,6 +187,7 @@ static inline void set_pte(pte_t *ptep, pte_t pteval) 
	}

#endif

}

#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)



static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)

{
@@ -399,12 +397,15 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 


extern void __update_tlb(struct vm_area_struct *vma, unsigned long address,

	pte_t pte);

extern void __update_cache(struct vm_area_struct *vma, unsigned long address,

	pte_t pte);



static inline void update_mmu_cache(struct vm_area_struct *vma,

	unsigned long address, pte_t *ptep)

{

	pte_t pte = *ptep;

	__update_tlb(vma, address, pte);

	__update_cache(vma, address, pte);

}



static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,

arch/mips/mm/cache.c

+8 −19
Original line number Diff line number Diff line
@@ -119,36 +119,25 @@ void __flush_anon_page(struct page *page, unsigned long vmaddr) 


EXPORT_SYMBOL(__flush_anon_page);



static void mips_flush_dcache_from_pte(pte_t pteval, unsigned long address)

void __update_cache(struct vm_area_struct *vma, unsigned long address,

	pte_t pte)

{

	struct page *page;

	unsigned long pfn = pte_pfn(pteval);

	unsigned long pfn, addr;

	int exec = (vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc;



	pfn = pte_pfn(pte);

	if (unlikely(!pfn_valid(pfn)))

		return;



	page = pfn_to_page(pfn);

	if (page_mapping(page) && Page_dcache_dirty(page)) {

		unsigned long page_addr = (unsigned long) page_address(page);



		if (!cpu_has_ic_fills_f_dc ||

		    pages_do_alias(page_addr, address & PAGE_MASK))

			flush_data_cache_page(page_addr);

		addr = (unsigned long) page_address(page);

		if (exec || pages_do_alias(addr, address & PAGE_MASK))

			flush_data_cache_page(addr);

		ClearPageDcacheDirty(page);

	}

}



void set_pte_at(struct mm_struct *mm, unsigned long addr,

        pte_t *ptep, pte_t pteval)

{

        if (cpu_has_dc_aliases || !cpu_has_ic_fills_f_dc) {

                if (pte_present(pteval))

                        mips_flush_dcache_from_pte(pteval, addr);

        }



        set_pte(ptep, pteval);

}



unsigned long _page_cachable_default;

EXPORT_SYMBOL(_page_cachable_default);