From 97f4533a60ce5d0cb35ff44a190111f81a987620 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Fri, 28 Nov 2014 11:53:54 +0100 Subject: [PATCH] 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: Juergen Gross Reviewed-by: David Vrabel Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: David Vrabel --- arch/x86/xen/p2m.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index 24cd9d17f57f..8676f3566fe3 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -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 @@ -796,15 +796,16 @@ 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, - sizeof(unsigned long)); + m2p_overrides = alloc_bootmem_align( + sizeof(*m2p_overrides) * M2P_OVERRIDE_HASH, + sizeof(unsigned long)); for (i = 0; i < M2P_OVERRIDE_HASH; i++) INIT_LIST_HEAD(&m2p_overrides[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); -- 2.30.2