Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758092AbZCMINU (ORCPT ); Fri, 13 Mar 2009 04:13:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753167AbZCMIMM (ORCPT ); Fri, 13 Mar 2009 04:12:12 -0400 Received: from gw.goop.org ([64.81.55.164]:34777 "EHLO abulafia.goop.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751933AbZCMIMJ (ORCPT ); Fri, 13 Mar 2009 04:12:09 -0400 From: Jeremy Fitzhardinge To: "H. Peter Anvin" Cc: the arch/x86 maintainers , Linux Kernel Mailing List , Xen-devel , Jeremy Fitzhardinge Subject: [PATCH 02/24] xen: separate p2m allocation from setting Date: Fri, 13 Mar 2009 01:11:38 -0700 Message-Id: <1236931920-6861-3-git-send-email-jeremy@goop.org> X-Mailer: git-send-email 1.6.0.6 In-Reply-To: <1236931920-6861-1-git-send-email-jeremy@goop.org> References: <1236931920-6861-1-git-send-email-jeremy@goop.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3454 Lines: 129 From: Jeremy Fitzhardinge When doing very early p2m setting, we need to separate setting from allocation, so split things up accordingly. Signed-off-by: Jeremy Fitzhardinge --- arch/x86/xen/mmu.c | 61 +++++++++++++++++++++++++++++++++++++-------------- arch/x86/xen/mmu.h | 3 ++ 2 files changed, 47 insertions(+), 17 deletions(-) diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index eceff87..d534986 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -233,47 +233,74 @@ unsigned long get_phys_to_machine(unsigned long pfn) } 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; - p = (void *)__get_free_page(GFP_KERNEL | __GFP_NOFAIL); - BUG_ON(p == NULL); + pfnp = &p2m_top[topidx]; + mfnp = &p2m_top_mfn[topidx]; for (i = 0; i < P2M_ENTRIES_PER_PAGE; i++) p[i] = INVALID_P2M_ENTRY; - if (cmpxchg(pp, p2m_missing, p) != p2m_missing) - free_page((unsigned long)p); - else + if (cmpxchg(pfnp, p2m_missing, p) == p2m_missing) { *mfnp = virt_to_mfn(p); + return true; + } + + return false; } -void set_phys_to_machine(unsigned long pfn, unsigned long mfn) +static void alloc_p2m(unsigned long pfn) { - unsigned topidx, idx; + unsigned long *p; - if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) { - BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY); - return; - } + p = (void *)__get_free_page(GFP_KERNEL | __GFP_NOFAIL); + BUG_ON(p == NULL); + + 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)) { BUG_ON(mfn != INVALID_P2M_ENTRY); - return; + return true; } topidx = p2m_top_index(pfn); if (p2m_top[topidx] == p2m_missing) { - /* no need to allocate a page to store an invalid entry */ if (mfn == INVALID_P2M_ENTRY) - return; - alloc_p2m(&p2m_top[topidx], &p2m_top_mfn[topidx]); + return true; + return false; } idx = p2m_index(pfn); 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) diff --git a/arch/x86/xen/mmu.h b/arch/x86/xen/mmu.h index 24d1b44..da73026 100644 --- a/arch/x86/xen/mmu.h +++ b/arch/x86/xen/mmu.h @@ -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); -- 1.6.0.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/