Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756627AbbEUTeK (ORCPT ); Thu, 21 May 2015 15:34:10 -0400 Received: from mail-qk0-f178.google.com ([209.85.220.178]:34323 "EHLO mail-qk0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756576AbbEUTd6 (ORCPT ); Thu, 21 May 2015 15:33:58 -0400 From: j.glisse@gmail.com To: akpm@linux-foundation.org Cc: , linux-mm@kvack.org, Linus Torvalds , , Mel Gorman , "H. Peter Anvin" , Peter Zijlstra , Andrea Arcangeli , Johannes Weiner , Larry Woodman , Rik van Riel , Dave Airlie , Brendan Conoboy , Joe Donohue , Duncan Poole , Sherry Cheung , Subhash Gutti , John Hubbard , Mark Hairgrove , Lucien Dunning , Cameron Buschardt , Arvind Gopalakrishnan , Haggai Eran , Shachar Raindel , Liran Liss , Roland Dreier , Ben Sander , Greg Stoner , John Bridgman , Michael Mantor , Paul Blinzer , Laurent Morichetti , Alexander Deucher , Oded Gabbay , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= Subject: [PATCH 12/36] HMM: add dirty range helper (to toggle dirty bit inside mirror page table). Date: Thu, 21 May 2015 15:31:21 -0400 Message-Id: <1432236705-4209-13-git-send-email-j.glisse@gmail.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1432236705-4209-1-git-send-email-j.glisse@gmail.com> References: <1432236705-4209-1-git-send-email-j.glisse@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3072 Lines: 92 From: Jérôme Glisse Device driver must properly toggle the dirty inside the mirror page table so dirtyness is properly accounted when core mm code needs to know. Provide a simple helper to toggle that bit for a range of address. Signed-off-by: Jérôme Glisse --- include/linux/hmm.h | 3 +++ mm/hmm.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 50 insertions(+) diff --git a/include/linux/hmm.h b/include/linux/hmm.h index ec05df8..186f497 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -253,6 +253,9 @@ int hmm_mirror_fault(struct hmm_mirror *mirror, struct hmm_event *event); void hmm_mirror_range_discard(struct hmm_mirror *mirror, unsigned long start, unsigned long end); +void hmm_mirror_range_dirty(struct hmm_mirror *mirror, + unsigned long start, + unsigned long end); #endif /* CONFIG_HMM */ diff --git a/mm/hmm.c b/mm/hmm.c index 4cab3f2..21fda9f 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -940,6 +940,53 @@ void hmm_mirror_range_discard(struct hmm_mirror *mirror, } EXPORT_SYMBOL(hmm_mirror_range_discard); +/* hmm_mirror_range_dirty() - toggle dirty bit for a range of address. + * + * @mirror: The mirror struct. + * @start: Start address of the range to discard (inclusive). + * @end: End address of the range to discard (exclusive). + * + * Call when device driver want to toggle the dirty bit for a range of address. + * Usefull when the device driver just want to toggle the bit for whole range + * without walking the mirror page table itself. + * + * Note this function does not directly dirty the page behind an address, but + * this will happen once address is invalidated or discard by device driver or + * core mm code. + */ +void hmm_mirror_range_dirty(struct hmm_mirror *mirror, + unsigned long start, + unsigned long end) +{ + struct hmm_pt_iter iter; + unsigned long addr; + + hmm_pt_iter_init(&iter); + for (addr = start; addr != end;) { + unsigned long cend, next; + dma_addr_t *hmm_pte; + + hmm_pte = hmm_pt_iter_update(&iter, &mirror->pt, addr); + if (!hmm_pte) { + addr = hmm_pt_iter_next(&iter, &mirror->pt, + addr, end); + continue; + } + cend = hmm_pt_level_next(&mirror->pt, addr, end, + mirror->pt.llevel - 1); + do { + next = hmm_pt_level_next(&mirror->pt, addr, cend, + mirror->pt.llevel); + if (!hmm_pte_test_valid_pfn(hmm_pte) || + !hmm_pte_test_write(hmm_pte)) + continue; + hmm_pte_set_dirty(hmm_pte); + } while (addr = next, hmm_pte++, addr != cend); + } + hmm_pt_iter_fini(&iter, &mirror->pt); +} +EXPORT_SYMBOL(hmm_mirror_range_dirty); + /* hmm_mirror_register() - register mirror against current process for a device. * * @mirror: The mirror struct being registered. -- 1.9.3 -- 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/