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Commit e791ca0f authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge
Browse files

xen: separate p2m allocation from setting 



When doing very early p2m setting, we need to separate setting
from allocation, so split things up accordingly.

Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
parent d6382bf7

arch/x86/xen/mmu.c

+44 −17
Original line number Original line Diff line number Diff line
@@ -233,47 +233,74 @@ unsigned long get_phys_to_machine(unsigned long pfn) 
}

}

EXPORT_SYMBOL_GPL(get_phys_to_machine);

EXPORT_SYMBOL_GPL(get_phys_to_machine);





static void alloc_p2m(unsigned long **pp, unsigned long *mfnp)

/* install a  new p2m_top page */

bool install_p2mtop_page(unsigned long pfn, unsigned long *p)

{

{

	unsigned long *p;

	unsigned topidx = p2m_top_index(pfn);

	unsigned long **pfnp, *mfnp;

	unsigned i;

	unsigned i;





	p = (void *)__get_free_page(GFP_KERNEL | __GFP_NOFAIL);

	pfnp = &p2m_top[topidx];

	BUG_ON(p == NULL);

	mfnp = &p2m_top_mfn[topidx];





	for (i = 0; i < P2M_ENTRIES_PER_PAGE; i++)

	for (i = 0; i < P2M_ENTRIES_PER_PAGE; i++)

		p[i] = INVALID_P2M_ENTRY;

		p[i] = INVALID_P2M_ENTRY;





	if (cmpxchg(pp, p2m_missing, p) != p2m_missing)

	if (cmpxchg(pfnp, p2m_missing, p) == p2m_missing) {

		free_page((unsigned long)p);

	else

		*mfnp = virt_to_mfn(p);

		*mfnp = virt_to_mfn(p);

		return true;

	}

	}





void set_phys_to_machine(unsigned long pfn, unsigned long mfn)

	return false;

}



static void alloc_p2m(unsigned long pfn)

{

{

	unsigned topidx, idx;

	unsigned long *p;





	if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) {

	p = (void *)__get_free_page(GFP_KERNEL | __GFP_NOFAIL);

		BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);

	BUG_ON(p == NULL);

		return;



	if (!install_p2mtop_page(pfn, p))

		free_page((unsigned long)p);

}

}





/* Try to install p2m mapping; fail if intermediate bits missing */

bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)

{

	unsigned topidx, idx;



	if (unlikely(pfn >= MAX_DOMAIN_PAGES)) {

	if (unlikely(pfn >= MAX_DOMAIN_PAGES)) {

		BUG_ON(mfn != INVALID_P2M_ENTRY);

		BUG_ON(mfn != INVALID_P2M_ENTRY);

		return;

		return true;

	}

	}





	topidx = p2m_top_index(pfn);

	topidx = p2m_top_index(pfn);

	if (p2m_top[topidx] == p2m_missing) {

	if (p2m_top[topidx] == p2m_missing) {

		/* no need to allocate a page to store an invalid entry */

		if (mfn == INVALID_P2M_ENTRY)

		if (mfn == INVALID_P2M_ENTRY)

			return;

			return true;

		alloc_p2m(&p2m_top[topidx], &p2m_top_mfn[topidx]);

		return false;

	}

	}





	idx = p2m_index(pfn);

	idx = p2m_index(pfn);

	p2m_top[topidx][idx] = mfn;

	p2m_top[topidx][idx] = mfn;



	return true;

}



void set_phys_to_machine(unsigned long pfn, unsigned long mfn)

{

	if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) {

		BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);

		return;

	}



	if (unlikely(!__set_phys_to_machine(pfn, mfn)))  {

		alloc_p2m(pfn);



		if (!__set_phys_to_machine(pfn, mfn))

			BUG();

	}

}

}





unsigned long arbitrary_virt_to_mfn(void *vaddr)

unsigned long arbitrary_virt_to_mfn(void *vaddr)

arch/x86/xen/mmu.h

+3 −0
Original line number Original line Diff line number Diff line
@@ -11,6 +11,9 @@ enum pt_level { 
};

};









bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);

bool install_p2mtop_page(unsigned long pfn, unsigned long *p);



void set_pte_mfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags);

void set_pte_mfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags);