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Commit b8bcfe99 authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge
Browse files

x86/paravirt: remove lazy mode in interrupts 



Impact: simplification, robustness

Make paravirt_lazy_mode() always return PARAVIRT_LAZY_NONE
when in an interrupt.  This prevents interrupt code from
accidentally inheriting an outer lazy state, and instead
does everything synchronously.  Outer batched operations
are left deferred.

Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
parent a8a93f3f

arch/x86/kernel/paravirt.c

+3 −0
Original line number Diff line number Diff line
@@ -282,6 +282,9 @@ void paravirt_leave_lazy_cpu(void) 


enum paravirt_lazy_mode paravirt_get_lazy_mode(void)

{

	if (in_interrupt())

		return PARAVIRT_LAZY_NONE;



	return __get_cpu_var(paravirt_lazy_mode);

}

arch/x86/mm/fault.c

+2 −4
Original line number Diff line number Diff line
@@ -225,12 +225,10 @@ static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address) 
	if (!pmd_present(*pmd_k))

		return NULL;



	if (!pmd_present(*pmd)) {

	if (!pmd_present(*pmd))

		set_pmd(pmd, *pmd_k);

		arch_flush_lazy_mmu_mode();

	} else {

	else

		BUG_ON(pmd_page(*pmd) != pmd_page(*pmd_k));

	}



	return pmd_k;

}

arch/x86/mm/highmem_32.c

+0 −2
Original line number Diff line number Diff line
@@ -87,7 +87,6 @@ void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot) 
	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);

	BUG_ON(!pte_none(*(kmap_pte-idx)));

	set_pte(kmap_pte-idx, mk_pte(page, prot));

	arch_flush_lazy_mmu_mode();



	return (void *)vaddr;

}
@@ -117,7 +116,6 @@ void kunmap_atomic(void *kvaddr, enum km_type type) 
#endif

	}



	arch_flush_lazy_mmu_mode();

	pagefault_enable();

}

arch/x86/mm/iomap_32.c

+0 −1
Original line number Diff line number Diff line
@@ -74,7 +74,6 @@ iounmap_atomic(void *kvaddr, enum km_type type) 
	if (vaddr == __fix_to_virt(FIX_KMAP_BEGIN+idx))

		kpte_clear_flush(kmap_pte-idx, vaddr);



	arch_flush_lazy_mmu_mode();

	pagefault_enable();

}

EXPORT_SYMBOL_GPL(iounmap_atomic);

arch/x86/mm/pageattr.c

+0 −14
Original line number Diff line number Diff line
@@ -824,13 +824,6 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages, 


	vm_unmap_aliases();



	/*

	 * If we're called with lazy mmu updates enabled, the

	 * in-memory pte state may be stale.  Flush pending updates to

	 * bring them up to date.

	 */

	arch_flush_lazy_mmu_mode();



	cpa.vaddr = addr;

	cpa.numpages = numpages;

	cpa.mask_set = mask_set;
@@ -873,13 +866,6 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages, 
	} else

		cpa_flush_all(cache);



	/*

	 * If we've been called with lazy mmu updates enabled, then

	 * make sure that everything gets flushed out before we

	 * return.

	 */

	arch_flush_lazy_mmu_mode();



out:

	return ret;

}