Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1207094

[PATCH 10/15] HMM: use CPU page table during invalidation.

From Jérôme Glisse <jglisse@redhat.com>
Newsgroups linux.kernel
Subject [PATCH 10/15] HMM: use CPU page table during invalidation.
Date 2015-08-13 21:20 +0200
Message-ID <pX6cH-43o-55@gated-at.bofh.it> (permalink)
References <pX6cF-43o-5@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw

From: Jerome Glisse <jglisse@redhat.com>

Once we store the dma mapping inside the secondary page table we can
no longer easily find back the page backing an address. Instead use
the cpu page table which still has the proper information, except for
the invalidate_page() case which is handled by using the page passed
by the mmu_notifier layer.

Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
---
 mm/hmm.c | 53 +++++++++++++++++++++++++++++++++++------------------
 1 file changed, 35 insertions(+), 18 deletions(-)

diff --git a/mm/hmm.c b/mm/hmm.c
index f0c3c81..d652233 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -47,9 +47,11 @@
 static struct mmu_notifier_ops hmm_notifier_ops;
 static void hmm_mirror_kill(struct hmm_mirror *mirror);
 static inline int hmm_mirror_update(struct hmm_mirror *mirror,
-				    struct hmm_event *event);
+				    struct hmm_event *event,
+				    struct page *page);
 static void hmm_mirror_update_pt(struct hmm_mirror *mirror,
-				 struct hmm_event *event);
+				 struct hmm_event *event,
+				 struct page *page);
 
 
 /* hmm_event - use to track information relating to an event.
@@ -223,7 +225,9 @@ again:
 	}
 }
 
-static void hmm_update(struct hmm *hmm, struct hmm_event *event)
+static void hmm_update(struct hmm *hmm,
+		       struct hmm_event *event,
+		       struct page *page)
 {
 	struct hmm_mirror *mirror;
 
@@ -236,7 +240,7 @@ static void hmm_update(struct hmm *hmm, struct hmm_event *event)
 again:
 	down_read(&hmm->rwsem);
 	hlist_for_each_entry(mirror, &hmm->mirrors, mlist)
-		if (hmm_mirror_update(mirror, event)) {
+		if (hmm_mirror_update(mirror, event, page)) {
 			mirror = hmm_mirror_ref(mirror);
 			up_read(&hmm->rwsem);
 			hmm_mirror_kill(mirror);
@@ -304,7 +308,7 @@ static void hmm_notifier_release(struct mmu_notifier *mn, struct mm_struct *mm)
 
 		/* Make sure everything is unmapped. */
 		hmm_event_init(&event, mirror->hmm, 0, -1UL, HMM_MUNMAP);
-		hmm_mirror_update(mirror, &event);
+		hmm_mirror_update(mirror, &event, NULL);
 
 		mirror->device->ops->release(mirror);
 		hmm_mirror_unref(&mirror);
@@ -338,9 +342,10 @@ static void hmm_mmu_mprot_to_etype(struct mm_struct *mm,
 	*etype = HMM_NONE;
 }
 
-static void hmm_notifier_invalidate_range_start(struct mmu_notifier *mn,
-					struct mm_struct *mm,
-					const struct mmu_notifier_range *range)
+static void hmm_notifier_invalidate(struct mmu_notifier *mn,
+				    struct mm_struct *mm,
+				    struct page *page,
+				    const struct mmu_notifier_range *range)
 {
 	struct hmm_event event;
 	unsigned long start = range->start, end = range->end;
@@ -379,7 +384,14 @@ static void hmm_notifier_invalidate_range_start(struct mmu_notifier *mn,
 
 	hmm_event_init(&event, hmm, start, end, event.etype);
 
-	hmm_update(hmm, &event);
+	hmm_update(hmm, &event, page);
+}
+
+static void hmm_notifier_invalidate_range_start(struct mmu_notifier *mn,
+					struct mm_struct *mm,
+					const struct mmu_notifier_range *range)
+{
+	hmm_notifier_invalidate(mn, mm, NULL, range);
 }
 
 static void hmm_notifier_invalidate_page(struct mmu_notifier *mn,
@@ -393,7 +405,7 @@ static void hmm_notifier_invalidate_page(struct mmu_notifier *mn,
 	range.start = addr & PAGE_MASK;
 	range.end = range.start + PAGE_SIZE;
 	range.event = mmu_event;
-	hmm_notifier_invalidate_range_start(mn, mm, &range);
+	hmm_notifier_invalidate(mn, mm, page, &range);
 }
 
 static struct mmu_notifier_ops hmm_notifier_ops = {
@@ -545,23 +557,27 @@ void hmm_mirror_unref(struct hmm_mirror **mirror)
 EXPORT_SYMBOL(hmm_mirror_unref);
 
 static inline int hmm_mirror_update(struct hmm_mirror *mirror,
-				    struct hmm_event *event)
+				    struct hmm_event *event,
+				    struct page *page)
 {
 	struct hmm_device *device = mirror->device;
 	int ret = 0;
 
 	ret = device->ops->update(mirror, event);
-	hmm_mirror_update_pt(mirror, event);
+	hmm_mirror_update_pt(mirror, event, page);
 	return ret;
 }
 
 static void hmm_mirror_update_pt(struct hmm_mirror *mirror,
-				 struct hmm_event *event)
+				 struct hmm_event *event,
+				 struct page *page)
 {
 	unsigned long addr;
 	struct hmm_pt_iter iter;
+	struct mm_pt_iter mm_iter;
 
 	hmm_pt_iter_init(&iter, &mirror->pt);
+	mm_pt_iter_init(&mm_iter, mirror->hmm->mm);
 	for (addr = event->start; addr != event->end;) {
 		unsigned long next = event->end;
 		dma_addr_t *hmm_pte;
@@ -582,10 +598,10 @@ static void hmm_mirror_update_pt(struct hmm_mirror *mirror,
 				continue;
 			if (hmm_pte_test_and_clear_dirty(hmm_pte) &&
 			    hmm_pte_test_write(hmm_pte)) {
-				struct page *page;
-
-				page = pfn_to_page(hmm_pte_pfn(*hmm_pte));
-				set_page_dirty(page);
+				page = page ? : mm_pt_iter_page(&mm_iter, addr);
+				if (page)
+					set_page_dirty(page);
+				page = NULL;
 			}
 			*hmm_pte &= event->pte_mask;
 			if (hmm_pte_test_valid_pfn(hmm_pte))
@@ -595,6 +611,7 @@ static void hmm_mirror_update_pt(struct hmm_mirror *mirror,
 		hmm_pt_iter_directory_unlock(&iter);
 	}
 	hmm_pt_iter_fini(&iter);
+	mm_pt_iter_fini(&mm_iter);
 }
 
 static inline bool hmm_mirror_is_dead(struct hmm_mirror *mirror)
@@ -979,7 +996,7 @@ static void hmm_mirror_kill(struct hmm_mirror *mirror)
 
 		/* Make sure everything is unmapped. */
 		hmm_event_init(&event, mirror->hmm, 0, -1UL, HMM_MUNMAP);
-		hmm_mirror_update(mirror, &event);
+		hmm_mirror_update(mirror, &event, NULL);
 
 		device->ops->release(mirror);
 		hmm_mirror_unref(&mirror);
-- 
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/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

HMM (Heterogeneous Memory Management) v10 Jérôme Glisse <jglisse@redhat.com> - 2015-08-13 21:20 +0200
  [PATCH 13/15] HMM: DMA map memory on behalf of device driver v2. Jérôme Glisse <jglisse@redhat.com> - 2015-08-13 21:20 +0200
  [PATCH 03/15] mmu_notifier: pass page pointer to mmu_notifier_invalidate_page() v2 Jérôme Glisse <jglisse@redhat.com> - 2015-08-13 21:20 +0200
  [PATCH 08/15] HMM: add device page fault support v4. Jérôme Glisse <jglisse@redhat.com> - 2015-08-13 21:20 +0200
  [PATCH 09/15] HMM: add mm page table iterator helpers. Jérôme Glisse <jglisse@redhat.com> - 2015-08-13 21:20 +0200
  [PATCH 15/15] hmm/dummy: dummy driver for testing and showcasing the HMM API Jérôme Glisse <jglisse@redhat.com> - 2015-08-13 21:20 +0200
  [PATCH 14/15] HMM: add documentation explaining HMM internals and how to use it. Jérôme Glisse <jglisse@redhat.com> - 2015-08-13 21:20 +0200
  [PATCH 10/15] HMM: use CPU page table during invalidation. Jérôme Glisse <jglisse@redhat.com> - 2015-08-13 21:20 +0200
  [PATCH 11/15] HMM: add discard range helper (to clear and free resources for a range). Jérôme Glisse <jglisse@redhat.com> - 2015-08-13 21:20 +0200
  [PATCH 06/15] HMM: add HMM page table v4. Jérôme Glisse <jglisse@redhat.com> - 2015-08-13 21:20 +0200
  [PATCH 07/15] HMM: add per mirror page table v4. Jérôme Glisse <jglisse@redhat.com> - 2015-08-13 21:20 +0200
  [PATCH 12/15] HMM: add dirty range helper (toggle dirty bit inside mirror page table) v2. Jérôme Glisse <jglisse@redhat.com> - 2015-08-13 21:20 +0200

csiph-web