From patchwork Mon Jul 7 20:26:54 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Stabellini X-Patchwork-Id: 4497821 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id E36EABEEAA for ; Mon, 7 Jul 2014 20:35:27 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 06102202EB for ; Mon, 7 Jul 2014 20:35:27 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1B52A201B4 for ; Mon, 7 Jul 2014 20:35:26 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1X4Fb7-0002Pp-W5; Mon, 07 Jul 2014 20:33:14 +0000 Received: from smtp02.citrix.com ([66.165.176.63]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1X4FWB-0008Gr-Hq for linux-arm-kernel@lists.infradead.org; Mon, 07 Jul 2014 20:28:08 +0000 X-IronPort-AV: E=Sophos;i="5.01,620,1400025600"; d="scan'208";a="150604300" Received: from accessns.citrite.net (HELO FTLPEX01CL02.citrite.net) ([10.9.154.239]) by FTLPIPO02.CITRIX.COM with ESMTP; 07 Jul 2014 20:27:44 +0000 Received: from ukmail1.uk.xensource.com (10.80.16.128) by smtprelay.citrix.com (10.13.107.79) with Microsoft SMTP Server id 14.3.181.6; Mon, 7 Jul 2014 16:27:43 -0400 Received: from kaball.uk.xensource.com ([10.80.2.59]) by ukmail1.uk.xensource.com with esmtp (Exim 4.69) (envelope-from ) id 1X4FVi-0000Y4-OR; Mon, 07 Jul 2014 21:27:38 +0100 From: Stefano Stabellini To: Subject: [RFC PATCH 2/2] xen/arm: remove mach_to_phys rbtree Date: Mon, 7 Jul 2014 21:26:54 +0100 Message-ID: <1404764815-31808-2-git-send-email-stefano.stabellini@eu.citrix.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: MIME-Version: 1.0 X-DLP: MIA2 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140707_132807_763129_6E927FEF X-CRM114-Status: GOOD ( 13.61 ) X-Spam-Score: -1.4 (-) Cc: Ian.Campbell@citrix.com, Stefano Stabellini , julien.grall@citrix.com, david.vrabel@citrix.com, v1ne2go@gmail.com, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Remove the rbtree used to keep track of machine to physical mappings: the frontend can grant the same page multiple times, leading to errors inserting or removing entries from the mach_to_phys tree. Linux only needed to know the physical address corresponding to a given machine address in swiotlb-xen. Now that swiotlb-xen can call the xen_dma_* functions passing the machine address directly, we can remove it. Signed-off-by: Stefano Stabellini --- arch/arm/include/asm/xen/page.h | 9 ------ arch/arm/xen/p2m.c | 64 +-------------------------------------- 2 files changed, 1 insertion(+), 72 deletions(-) diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h index ded062f..135c24a 100644 --- a/arch/arm/include/asm/xen/page.h +++ b/arch/arm/include/asm/xen/page.h @@ -33,7 +33,6 @@ typedef struct xpaddr { #define INVALID_P2M_ENTRY (~0UL) unsigned long __pfn_to_mfn(unsigned long pfn); -unsigned long __mfn_to_pfn(unsigned long mfn); extern struct rb_root phys_to_mach; static inline unsigned long pfn_to_mfn(unsigned long pfn) @@ -51,14 +50,6 @@ static inline unsigned long pfn_to_mfn(unsigned long pfn) static inline unsigned long mfn_to_pfn(unsigned long mfn) { - unsigned long pfn; - - if (phys_to_mach.rb_node != NULL) { - pfn = __mfn_to_pfn(mfn); - if (pfn != INVALID_P2M_ENTRY) - return pfn; - } - return mfn; } diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c index 97baf44..739ffcd 100644 --- a/arch/arm/xen/p2m.c +++ b/arch/arm/xen/p2m.c @@ -21,14 +21,12 @@ struct xen_p2m_entry { unsigned long pfn; unsigned long mfn; unsigned long nr_pages; - struct rb_node rbnode_mach; struct rb_node rbnode_phys; }; static rwlock_t p2m_lock; struct rb_root phys_to_mach = RB_ROOT; EXPORT_SYMBOL_GPL(phys_to_mach); -static struct rb_root mach_to_phys = RB_ROOT; static int xen_add_phys_to_mach_entry(struct xen_p2m_entry *new) { @@ -88,64 +86,6 @@ unsigned long __pfn_to_mfn(unsigned long pfn) } EXPORT_SYMBOL_GPL(__pfn_to_mfn); -static int xen_add_mach_to_phys_entry(struct xen_p2m_entry *new) -{ - struct rb_node **link = &mach_to_phys.rb_node; - struct rb_node *parent = NULL; - struct xen_p2m_entry *entry; - int rc = 0; - - while (*link) { - parent = *link; - entry = rb_entry(parent, struct xen_p2m_entry, rbnode_mach); - - if (new->mfn == entry->mfn) - goto err_out; - if (new->pfn == entry->pfn) - goto err_out; - - if (new->mfn < entry->mfn) - link = &(*link)->rb_left; - else - link = &(*link)->rb_right; - } - rb_link_node(&new->rbnode_mach, parent, link); - rb_insert_color(&new->rbnode_mach, &mach_to_phys); - goto out; - -err_out: - rc = -EINVAL; - pr_warn("%s: cannot add pfn=%pa -> mfn=%pa: pfn=%pa -> mfn=%pa already exists\n", - __func__, &new->pfn, &new->mfn, &entry->pfn, &entry->mfn); -out: - return rc; -} - -unsigned long __mfn_to_pfn(unsigned long mfn) -{ - struct rb_node *n = mach_to_phys.rb_node; - struct xen_p2m_entry *entry; - unsigned long irqflags; - - read_lock_irqsave(&p2m_lock, irqflags); - while (n) { - entry = rb_entry(n, struct xen_p2m_entry, rbnode_mach); - if (entry->mfn <= mfn && - entry->mfn + entry->nr_pages > mfn) { - read_unlock_irqrestore(&p2m_lock, irqflags); - return entry->pfn + (mfn - entry->mfn); - } - if (mfn < entry->mfn) - n = n->rb_left; - else - n = n->rb_right; - } - read_unlock_irqrestore(&p2m_lock, irqflags); - - return INVALID_P2M_ENTRY; -} -EXPORT_SYMBOL_GPL(__mfn_to_pfn); - 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) @@ -192,7 +132,6 @@ bool __set_phys_to_machine_multi(unsigned long pfn, p2m_entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys); if (p2m_entry->pfn <= pfn && p2m_entry->pfn + p2m_entry->nr_pages > pfn) { - rb_erase(&p2m_entry->rbnode_mach, &mach_to_phys); rb_erase(&p2m_entry->rbnode_phys, &phys_to_mach); write_unlock_irqrestore(&p2m_lock, irqflags); kfree(p2m_entry); @@ -217,8 +156,7 @@ bool __set_phys_to_machine_multi(unsigned long pfn, p2m_entry->mfn = mfn; write_lock_irqsave(&p2m_lock, irqflags); - if ((rc = xen_add_phys_to_mach_entry(p2m_entry) < 0) || - (rc = xen_add_mach_to_phys_entry(p2m_entry) < 0)) { + if ((rc = xen_add_phys_to_mach_entry(p2m_entry)) < 0) { write_unlock_irqrestore(&p2m_lock, irqflags); return false; }