Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752149AbaKKFoD (ORCPT ); Tue, 11 Nov 2014 00:44:03 -0500 Received: from cantor2.suse.de ([195.135.220.15]:59281 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751399AbaKKFn7 (ORCPT ); Tue, 11 Nov 2014 00:43:59 -0500 From: Juergen Gross To: linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com, konrad.wilk@oracle.com, david.vrabel@citrix.com, boris.ostrovsky@oracle.com, x86@kernel.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com Cc: Juergen Gross Subject: [PATCH V3 1/8] xen: Make functions static Date: Tue, 11 Nov 2014 06:43:39 +0100 Message-Id: <1415684626-18590-2-git-send-email-jgross@suse.com> X-Mailer: git-send-email 2.1.2 In-Reply-To: <1415684626-18590-1-git-send-email-jgross@suse.com> References: <1415684626-18590-1-git-send-email-jgross@suse.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Some functions in arch/x86/xen/p2m.c are used locally only. Make them static. Rearrange the functions in p2m.c to avoid forward declarations. While at it correct some style issues (long lines, use pr_warn()). Signed-off-by: Juergen Gross --- arch/x86/include/asm/xen/page.h | 6 - arch/x86/xen/p2m.c | 347 ++++++++++++++++++++-------------------- 2 files changed, 172 insertions(+), 181 deletions(-) diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h index c949923..6c16451 100644 --- a/arch/x86/include/asm/xen/page.h +++ b/arch/x86/include/asm/xen/page.h @@ -52,15 +52,9 @@ extern unsigned long set_phys_range_identity(unsigned long pfn_s, extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, struct gnttab_map_grant_ref *kmap_ops, struct page **pages, unsigned int count); -extern int m2p_add_override(unsigned long mfn, struct page *page, - struct gnttab_map_grant_ref *kmap_op); extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, struct gnttab_map_grant_ref *kmap_ops, struct page **pages, unsigned int count); -extern int m2p_remove_override(struct page *page, - struct gnttab_map_grant_ref *kmap_op, - unsigned long mfn); -extern struct page *m2p_find_override(unsigned long mfn); extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn); static inline unsigned long pfn_to_mfn(unsigned long pfn) diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index 9201a38..fa75842 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -896,6 +896,61 @@ static unsigned long mfn_hash(unsigned long mfn) return hash_long(mfn, M2P_OVERRIDE_HASH_SHIFT); } +/* Add an MFN override for a particular page */ +static int m2p_add_override(unsigned long mfn, struct page *page, + struct gnttab_map_grant_ref *kmap_op) +{ + unsigned long flags; + unsigned long pfn; + unsigned long uninitialized_var(address); + unsigned level; + pte_t *ptep = NULL; + + pfn = page_to_pfn(page); + if (!PageHighMem(page)) { + address = (unsigned long)__va(pfn << PAGE_SHIFT); + ptep = lookup_address(address, &level); + if (WARN(ptep == NULL || level != PG_LEVEL_4K, + "m2p_add_override: pfn %lx not mapped", pfn)) + return -EINVAL; + } + + if (kmap_op != NULL) { + if (!PageHighMem(page)) { + struct multicall_space mcs = + xen_mc_entry(sizeof(*kmap_op)); + + MULTI_grant_table_op(mcs.mc, + GNTTABOP_map_grant_ref, kmap_op, 1); + + xen_mc_issue(PARAVIRT_LAZY_MMU); + } + } + spin_lock_irqsave(&m2p_override_lock, flags); + list_add(&page->lru, &m2p_overrides[mfn_hash(mfn)]); + spin_unlock_irqrestore(&m2p_override_lock, flags); + + /* p2m(m2p(mfn)) == mfn: the mfn is already present somewhere in + * this domain. Set the FOREIGN_FRAME_BIT in the p2m for the other + * pfn so that the following mfn_to_pfn(mfn) calls will return the + * pfn from the m2p_override (the backend pfn) instead. + * We need to do this because the pages shared by the frontend + * (xen-blkfront) can be already locked (lock_page, called by + * do_read_cache_page); when the userspace backend tries to use them + * with direct_IO, mfn_to_pfn returns the pfn of the frontend, so + * do_blockdev_direct_IO is going to try to lock the same pages + * again resulting in a deadlock. + * As a side effect get_user_pages_fast might not be safe on the + * frontend pages while they are being shared with the backend, + * because mfn_to_pfn (that ends up being called by GUPF) will + * return the backend pfn rather than the frontend pfn. */ + pfn = mfn_to_pfn_no_overrides(mfn); + if (get_phys_to_machine(pfn) == mfn) + set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)); + + return 0; +} + int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, struct gnttab_map_grant_ref *kmap_ops, struct page **pages, unsigned int count) @@ -955,61 +1010,123 @@ out: } EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping); -/* Add an MFN override for a particular page */ -int m2p_add_override(unsigned long mfn, struct page *page, - struct gnttab_map_grant_ref *kmap_op) -{ - unsigned long flags; - unsigned long pfn; - unsigned long uninitialized_var(address); - unsigned level; - pte_t *ptep = NULL; - - pfn = page_to_pfn(page); - if (!PageHighMem(page)) { - address = (unsigned long)__va(pfn << PAGE_SHIFT); - ptep = lookup_address(address, &level); - if (WARN(ptep == NULL || level != PG_LEVEL_4K, - "m2p_add_override: pfn %lx not mapped", pfn)) - return -EINVAL; - } - - if (kmap_op != NULL) { - if (!PageHighMem(page)) { - struct multicall_space mcs = - xen_mc_entry(sizeof(*kmap_op)); - - MULTI_grant_table_op(mcs.mc, - GNTTABOP_map_grant_ref, kmap_op, 1); - - xen_mc_issue(PARAVIRT_LAZY_MMU); - } - } - spin_lock_irqsave(&m2p_override_lock, flags); - list_add(&page->lru, &m2p_overrides[mfn_hash(mfn)]); - spin_unlock_irqrestore(&m2p_override_lock, flags); - - /* p2m(m2p(mfn)) == mfn: the mfn is already present somewhere in - * this domain. Set the FOREIGN_FRAME_BIT in the p2m for the other - * pfn so that the following mfn_to_pfn(mfn) calls will return the - * pfn from the m2p_override (the backend pfn) instead. - * We need to do this because the pages shared by the frontend - * (xen-blkfront) can be already locked (lock_page, called by - * do_read_cache_page); when the userspace backend tries to use them - * with direct_IO, mfn_to_pfn returns the pfn of the frontend, so - * do_blockdev_direct_IO is going to try to lock the same pages - * again resulting in a deadlock. - * As a side effect get_user_pages_fast might not be safe on the - * frontend pages while they are being shared with the backend, - * because mfn_to_pfn (that ends up being called by GUPF) will - * return the backend pfn rather than the frontend pfn. */ - pfn = mfn_to_pfn_no_overrides(mfn); - if (get_phys_to_machine(pfn) == mfn) - set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)); - - return 0; -} -EXPORT_SYMBOL_GPL(m2p_add_override); +static struct page *m2p_find_override(unsigned long mfn) +{ + unsigned long flags; + struct list_head *bucket = &m2p_overrides[mfn_hash(mfn)]; + struct page *p, *ret; + + ret = NULL; + + spin_lock_irqsave(&m2p_override_lock, flags); + + list_for_each_entry(p, bucket, lru) { + if (page_private(p) == mfn) { + ret = p; + break; + } + } + + spin_unlock_irqrestore(&m2p_override_lock, flags); + + return ret; +} + +static int m2p_remove_override(struct page *page, + struct gnttab_map_grant_ref *kmap_op, + unsigned long mfn) +{ + unsigned long flags; + unsigned long pfn; + unsigned long uninitialized_var(address); + unsigned level; + pte_t *ptep = NULL; + + pfn = page_to_pfn(page); + + if (!PageHighMem(page)) { + address = (unsigned long)__va(pfn << PAGE_SHIFT); + ptep = lookup_address(address, &level); + + if (WARN(ptep == NULL || level != PG_LEVEL_4K, + "m2p_remove_override: pfn %lx not mapped", pfn)) + return -EINVAL; + } + + spin_lock_irqsave(&m2p_override_lock, flags); + list_del(&page->lru); + spin_unlock_irqrestore(&m2p_override_lock, flags); + + if (kmap_op != NULL) { + if (!PageHighMem(page)) { + struct multicall_space mcs; + struct gnttab_unmap_and_replace *unmap_op; + struct page *scratch_page = get_balloon_scratch_page(); + unsigned long scratch_page_address = (unsigned long) + __va(page_to_pfn(scratch_page) << PAGE_SHIFT); + + /* + * It might be that we queued all the m2p grant table + * hypercalls in a multicall, then m2p_remove_override + * get called before the multicall has actually been + * issued. In this case handle is going to -1 because + * it hasn't been modified yet. + */ + if (kmap_op->handle == -1) + xen_mc_flush(); + /* + * Now if kmap_op->handle is negative it means that the + * hypercall actually returned an error. + */ + if (kmap_op->handle == GNTST_general_error) { + pr_warn("m2p_remove_override: pfn %lx mfn %lx, failed to modify kernel mappings", + pfn, mfn); + put_balloon_scratch_page(); + return -1; + } + + xen_mc_batch(); + + mcs = __xen_mc_entry( + sizeof(struct gnttab_unmap_and_replace)); + unmap_op = mcs.args; + unmap_op->host_addr = kmap_op->host_addr; + unmap_op->new_addr = scratch_page_address; + unmap_op->handle = kmap_op->handle; + + MULTI_grant_table_op(mcs.mc, + GNTTABOP_unmap_and_replace, unmap_op, 1); + + mcs = __xen_mc_entry(0); + MULTI_update_va_mapping(mcs.mc, scratch_page_address, + pfn_pte(page_to_pfn(scratch_page), + PAGE_KERNEL_RO), 0); + + xen_mc_issue(PARAVIRT_LAZY_MMU); + + kmap_op->host_addr = 0; + put_balloon_scratch_page(); + } + } + + /* p2m(m2p(mfn)) == FOREIGN_FRAME(mfn): the mfn is already present + * somewhere in this domain, even before being added to the + * m2p_override (see comment above in m2p_add_override). + * If there are no other entries in the m2p_override corresponding + * to this mfn, then remove the FOREIGN_FRAME_BIT from the p2m for + * the original pfn (the one shared by the frontend): the backend + * cannot do any IO on this page anymore because it has been + * unshared. Removing the FOREIGN_FRAME_BIT from the p2m entry of + * the original pfn causes mfn_to_pfn(mfn) to return the frontend + * pfn again. */ + mfn &= ~FOREIGN_FRAME_BIT; + pfn = mfn_to_pfn_no_overrides(mfn); + if (get_phys_to_machine(pfn) == FOREIGN_FRAME(mfn) && + m2p_find_override(mfn) == NULL) + set_phys_to_machine(pfn, mfn); + + return 0; +} int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, struct gnttab_map_grant_ref *kmap_ops, @@ -1055,126 +1172,6 @@ out: } EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping); -int m2p_remove_override(struct page *page, - struct gnttab_map_grant_ref *kmap_op, - unsigned long mfn) -{ - unsigned long flags; - unsigned long pfn; - unsigned long uninitialized_var(address); - unsigned level; - pte_t *ptep = NULL; - - pfn = page_to_pfn(page); - - if (!PageHighMem(page)) { - address = (unsigned long)__va(pfn << PAGE_SHIFT); - ptep = lookup_address(address, &level); - - if (WARN(ptep == NULL || level != PG_LEVEL_4K, - "m2p_remove_override: pfn %lx not mapped", pfn)) - return -EINVAL; - } - - spin_lock_irqsave(&m2p_override_lock, flags); - list_del(&page->lru); - spin_unlock_irqrestore(&m2p_override_lock, flags); - - if (kmap_op != NULL) { - if (!PageHighMem(page)) { - struct multicall_space mcs; - struct gnttab_unmap_and_replace *unmap_op; - struct page *scratch_page = get_balloon_scratch_page(); - unsigned long scratch_page_address = (unsigned long) - __va(page_to_pfn(scratch_page) << PAGE_SHIFT); - - /* - * It might be that we queued all the m2p grant table - * hypercalls in a multicall, then m2p_remove_override - * get called before the multicall has actually been - * issued. In this case handle is going to -1 because - * it hasn't been modified yet. - */ - if (kmap_op->handle == -1) - xen_mc_flush(); - /* - * Now if kmap_op->handle is negative it means that the - * hypercall actually returned an error. - */ - if (kmap_op->handle == GNTST_general_error) { - printk(KERN_WARNING "m2p_remove_override: " - "pfn %lx mfn %lx, failed to modify kernel mappings", - pfn, mfn); - put_balloon_scratch_page(); - return -1; - } - - xen_mc_batch(); - - mcs = __xen_mc_entry( - sizeof(struct gnttab_unmap_and_replace)); - unmap_op = mcs.args; - unmap_op->host_addr = kmap_op->host_addr; - unmap_op->new_addr = scratch_page_address; - unmap_op->handle = kmap_op->handle; - - MULTI_grant_table_op(mcs.mc, - GNTTABOP_unmap_and_replace, unmap_op, 1); - - mcs = __xen_mc_entry(0); - MULTI_update_va_mapping(mcs.mc, scratch_page_address, - pfn_pte(page_to_pfn(scratch_page), - PAGE_KERNEL_RO), 0); - - xen_mc_issue(PARAVIRT_LAZY_MMU); - - kmap_op->host_addr = 0; - put_balloon_scratch_page(); - } - } - - /* p2m(m2p(mfn)) == FOREIGN_FRAME(mfn): the mfn is already present - * somewhere in this domain, even before being added to the - * m2p_override (see comment above in m2p_add_override). - * If there are no other entries in the m2p_override corresponding - * to this mfn, then remove the FOREIGN_FRAME_BIT from the p2m for - * the original pfn (the one shared by the frontend): the backend - * cannot do any IO on this page anymore because it has been - * unshared. Removing the FOREIGN_FRAME_BIT from the p2m entry of - * the original pfn causes mfn_to_pfn(mfn) to return the frontend - * pfn again. */ - mfn &= ~FOREIGN_FRAME_BIT; - pfn = mfn_to_pfn_no_overrides(mfn); - if (get_phys_to_machine(pfn) == FOREIGN_FRAME(mfn) && - m2p_find_override(mfn) == NULL) - set_phys_to_machine(pfn, mfn); - - return 0; -} -EXPORT_SYMBOL_GPL(m2p_remove_override); - -struct page *m2p_find_override(unsigned long mfn) -{ - unsigned long flags; - struct list_head *bucket = &m2p_overrides[mfn_hash(mfn)]; - struct page *p, *ret; - - ret = NULL; - - spin_lock_irqsave(&m2p_override_lock, flags); - - list_for_each_entry(p, bucket, lru) { - if (page_private(p) == mfn) { - ret = p; - break; - } - } - - spin_unlock_irqrestore(&m2p_override_lock, flags); - - return ret; -} - unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn) { struct page *p = m2p_find_override(mfn); -- 2.1.2 -- 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/