Commit 97f4533a authored by Juergen Gross's avatar Juergen Gross Committed by David Vrabel
Browse files

xen: Delay m2p_override initialization 



The m2p overrides are used to be able to find the local pfn for a
foreign mfn mapped into the domain. They are used by driver backends
having to access frontend data.

As this functionality isn't used in early boot it makes no sense to
initialize the m2p override functions very early. It can be done
later without doing any harm, removing the need for allocating memory
via extend_brk().

While at it make some m2p override functions static as they are only
used internally.

Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Reviewed-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
parent 1f3ac86b

arch/x86/xen/p2m.c

+12 −7
Original line number Diff line number Diff line
@@ -428,8 +428,6 @@ void __init xen_build_dynamic_phys_to_machine(void) 
		}

		p2m_top[topidx][mididx] = &mfn_list[pfn];

	}



	m2p_override_init();

}

#ifdef CONFIG_X86_64

unsigned long __init xen_revector_p2m_tree(void)
@@ -500,13 +498,15 @@ unsigned long __init xen_revector_p2m_tree(void) 
		}

		/* This should be the leafs allocated for identity from _brk. */

	}

	return (unsigned long)mfn_list;



	m2p_override_init();

	return (unsigned long)mfn_list;

}

#else

unsigned long __init xen_revector_p2m_tree(void)

{

	use_brk = 0;

	m2p_override_init();

	return 0;

}

#endif
@@ -796,14 +796,15 @@ bool set_phys_to_machine(unsigned long pfn, unsigned long mfn) 
#define M2P_OVERRIDE_HASH_SHIFT	10

#define M2P_OVERRIDE_HASH	(1 << M2P_OVERRIDE_HASH_SHIFT)



static RESERVE_BRK_ARRAY(struct list_head, m2p_overrides, M2P_OVERRIDE_HASH);

static struct list_head *m2p_overrides;

static DEFINE_SPINLOCK(m2p_override_lock);



static void __init m2p_override_init(void)

{

	unsigned i;



	m2p_overrides = extend_brk(sizeof(*m2p_overrides) * M2P_OVERRIDE_HASH,

	m2p_overrides = alloc_bootmem_align(

				sizeof(*m2p_overrides) * M2P_OVERRIDE_HASH,

				sizeof(unsigned long));



	for (i = 0; i < M2P_OVERRIDE_HASH; i++)
@@ -932,10 +933,14 @@ EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping); 
static struct page *m2p_find_override(unsigned long mfn)

{

	unsigned long flags;

	struct list_head *bucket = &m2p_overrides[mfn_hash(mfn)];

	struct list_head *bucket;

	struct page *p, *ret;



	if (unlikely(!m2p_overrides))

		return NULL;



	ret = NULL;

	bucket = &m2p_overrides[mfn_hash(mfn)];



	spin_lock_irqsave(&m2p_override_lock, flags);

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