From 7108c9ce8f6e59f775b0c8250dba52b569b6cba2 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Fri, 28 Nov 2014 11:53:52 +0100 Subject: [PATCH] xen: use common page allocation function in p2m.c In arch/x86/xen/p2m.c three different allocation functions for obtaining a memory page are used: extend_brk(), alloc_bootmem_align() or __get_free_page(). Which of those functions is used depends on the progress of the boot process of the system. Introduce a common allocation routine selecting the to be called allocation routine dynamically based on the boot progress. This allows moving initialization steps without having to care about changing allocation calls. Signed-off-by: Juergen Gross Signed-off-by: David Vrabel --- arch/x86/xen/mmu.c | 2 ++ arch/x86/xen/p2m.c | 57 +++++++++++++++++++++++++++++++++--------------------- 2 files changed, 37 insertions(+), 22 deletions(-) diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index a8a1a3d..b995b871 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -1219,6 +1219,8 @@ static void __init xen_pagetable_init(void) paging_init(); #ifdef CONFIG_X86_64 xen_pagetable_p2m_copy(); +#else + xen_revector_p2m_tree(); #endif /* Allocate and initialize top and mid mfn levels for p2m structure */ xen_build_mfn_list_list(); diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index 2d8b908..fa53dc2 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -164,6 +164,7 @@ #include #include #include +#include #include #include @@ -204,6 +205,8 @@ RESERVE_BRK(p2m_mid, PAGE_SIZE * (MAX_DOMAIN_PAGES / (P2M_PER_PAGE * P2M_MID_PER */ RESERVE_BRK(p2m_identity_remap, PAGE_SIZE * 2 * 3 * MAX_REMAP_RANGES); +static int use_brk = 1; + static inline unsigned p2m_top_index(unsigned long pfn) { BUG_ON(pfn >= MAX_P2M_PFN); @@ -268,6 +271,24 @@ static void p2m_init(unsigned long *p2m) p2m[i] = INVALID_P2M_ENTRY; } +static void * __ref alloc_p2m_page(void) +{ + if (unlikely(use_brk)) + return extend_brk(PAGE_SIZE, PAGE_SIZE); + + if (unlikely(!slab_is_available())) + return alloc_bootmem_align(PAGE_SIZE, PAGE_SIZE); + + return (void *)__get_free_page(GFP_KERNEL | __GFP_REPEAT); +} + +/* Only to be called in case of a race for a page just allocated! */ +static void free_p2m_page(void *p) +{ + BUG_ON(!slab_is_available()); + free_page((unsigned long)p); +} + /* * Build the parallel p2m_top_mfn and p2m_mid_mfn structures * @@ -287,13 +308,13 @@ void __ref xen_build_mfn_list_list(void) /* Pre-initialize p2m_top_mfn to be completely missing */ if (p2m_top_mfn == NULL) { - p2m_mid_missing_mfn = alloc_bootmem_align(PAGE_SIZE, PAGE_SIZE); + p2m_mid_missing_mfn = alloc_p2m_page(); p2m_mid_mfn_init(p2m_mid_missing_mfn, p2m_missing); - p2m_top_mfn_p = alloc_bootmem_align(PAGE_SIZE, PAGE_SIZE); + p2m_top_mfn_p = alloc_p2m_page(); p2m_top_mfn_p_init(p2m_top_mfn_p); - p2m_top_mfn = alloc_bootmem_align(PAGE_SIZE, PAGE_SIZE); + p2m_top_mfn = alloc_p2m_page(); p2m_top_mfn_init(p2m_top_mfn); } else { /* Reinitialise, mfn's all change after migration */ @@ -327,7 +348,7 @@ void __ref xen_build_mfn_list_list(void) * missing parts of the mfn tree after * runtime. */ - mid_mfn_p = alloc_bootmem_align(PAGE_SIZE, PAGE_SIZE); + mid_mfn_p = alloc_p2m_page(); p2m_mid_mfn_init(mid_mfn_p, p2m_missing); p2m_top_mfn_p[topidx] = mid_mfn_p; @@ -364,17 +385,17 @@ void __init xen_build_dynamic_phys_to_machine(void) max_pfn = min(MAX_DOMAIN_PAGES, xen_start_info->nr_pages); xen_max_p2m_pfn = max_pfn; - p2m_missing = extend_brk(PAGE_SIZE, PAGE_SIZE); + p2m_missing = alloc_p2m_page(); p2m_init(p2m_missing); - p2m_identity = extend_brk(PAGE_SIZE, PAGE_SIZE); + p2m_identity = alloc_p2m_page(); p2m_init(p2m_identity); - p2m_mid_missing = extend_brk(PAGE_SIZE, PAGE_SIZE); + p2m_mid_missing = alloc_p2m_page(); p2m_mid_init(p2m_mid_missing, p2m_missing); - p2m_mid_identity = extend_brk(PAGE_SIZE, PAGE_SIZE); + p2m_mid_identity = alloc_p2m_page(); p2m_mid_init(p2m_mid_identity, p2m_identity); - p2m_top = extend_brk(PAGE_SIZE, PAGE_SIZE); + p2m_top = alloc_p2m_page(); p2m_top_init(p2m_top); /* @@ -387,7 +408,7 @@ void __init xen_build_dynamic_phys_to_machine(void) unsigned mididx = p2m_mid_index(pfn); if (p2m_top[topidx] == p2m_mid_missing) { - unsigned long **mid = extend_brk(PAGE_SIZE, PAGE_SIZE); + unsigned long **mid = alloc_p2m_page(); p2m_mid_init(mid, p2m_missing); p2m_top[topidx] = mid; @@ -420,6 +441,7 @@ unsigned long __init xen_revector_p2m_tree(void) unsigned long *mfn_list = NULL; unsigned long size; + use_brk = 0; va_start = xen_start_info->mfn_list; /*We copy in increments of P2M_PER_PAGE * sizeof(unsigned long), * so make sure it is rounded up to that */ @@ -484,6 +506,7 @@ unsigned long __init xen_revector_p2m_tree(void) #else unsigned long __init xen_revector_p2m_tree(void) { + use_brk = 0; return 0; } #endif @@ -510,16 +533,6 @@ unsigned long get_phys_to_machine(unsigned long pfn) } EXPORT_SYMBOL_GPL(get_phys_to_machine); -static void *alloc_p2m_page(void) -{ - return (void *)__get_free_page(GFP_KERNEL | __GFP_REPEAT); -} - -static void free_p2m_page(void *p) -{ - free_page((unsigned long)p); -} - /* * Fully allocate the p2m structure for a given pfn. We need to check * that both the top and mid levels are allocated, and make sure the @@ -624,7 +637,7 @@ static bool __init early_alloc_p2m(unsigned long pfn, bool check_boundary) return false; /* Boundary cross-over for the edges: */ - p2m = extend_brk(PAGE_SIZE, PAGE_SIZE); + p2m = alloc_p2m_page(); p2m_init(p2m); @@ -640,7 +653,7 @@ static bool __init early_alloc_p2m_middle(unsigned long pfn) mid = p2m_top[topidx]; if (mid == p2m_mid_missing) { - mid = extend_brk(PAGE_SIZE, PAGE_SIZE); + mid = alloc_p2m_page(); p2m_mid_init(mid, p2m_missing); -- 2.7.4