From 9ea4feecc39dbed60496fa181d70fdb9d73c7250 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 5 May 2015 09:17:29 +0100
Subject: [PATCH 1/9] drm/i915: Store device pointer in contexts for late
 tracepoint usafe

[ 1572.417121] BUG: unable to handle kernel NULL pointer dereference at           (null)
[ 1572.421010] IP: [<ffffffffa00b2514>] ftrace_raw_event_i915_context+0x5d/0x70 [i915]
[ 1572.424970] PGD 1766a3067 PUD 1767a2067 PMD 0
[ 1572.428892] Oops: 0000 [#1] SMP
[ 1572.432787] Modules linked in: ipv6 dm_mod iTCO_wdt iTCO_vendor_support snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_controller snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_timer snd soundcore serio_raw pcspkr lpc_ich i2c_i801 mfd_core battery ac acpi_cpufreq i915 button video drm_kms_helper drm
[ 1572.441720] CPU: 2 PID: 18853 Comm: kworker/u8:0 Not tainted 4.0.0_kcloud_3f0360_20150429+ #588
[ 1572.446298] Workqueue: i915 i915_gem_retire_work_handler [i915]
[ 1572.450876] task: ffff880002f428f0 ti: ffff880035724000 task.ti: ffff880035724000
[ 1572.455557] RIP: 0010:[<ffffffffa00b2514>]  [<ffffffffa00b2514>] ftrace_raw_event_i915_context+0x5d/0x70 [i915]
[ 1572.460423] RSP: 0018:ffff880035727ce8  EFLAGS: 00010286
[ 1572.465262] RAX: ffff880073f1643c RBX: ffff880002da9058 RCX: ffff880073e5db40
[ 1572.470179] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880035727ce8
[ 1572.475107] RBP: ffff88007bb11a00 R08: 0000000000000000 R09: 0000000000000000
[ 1572.480034] R10: 0000000000362200 R11: 0000000000000008 R12: 0000000000000000
[ 1572.484952] R13: ffff880035727d78 R14: ffff880002dc1c98 R15: ffff880002dc1dc8
[ 1572.489886] FS:  0000000000000000(0000) GS:ffff88017fd00000(0000) knlGS:0000000000000000
[ 1572.494883] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 1572.499859] CR2: 0000000000000000 CR3: 000000017572a000 CR4: 00000000001006e0
[ 1572.504842] Stack:
[ 1572.509834]  ffff88017b0090c0 ffff880073f16438 ffff880002da9058 ffff880073f1643c
[ 1572.514904]  0000000000000246 ffff880100000000 ffff88007bb11a00 ffff880002ddeb10
[ 1572.519985]  ffff8801759f79c0 ffffffffa0092ff0 0000000000000000 ffff88007bb11a00
[ 1572.525049] Call Trace:
[ 1572.530093]  [<ffffffffa0092ff0>] ? i915_gem_context_free+0xa8/0xc1 [i915]
[ 1572.535227]  [<ffffffffa009b969>] ? i915_gem_request_free+0x4e/0x50 [i915]
[ 1572.540347]  [<ffffffffa00b5533>] ? intel_execlists_retire_requests+0x14c/0x159 [i915]
[ 1572.545500]  [<ffffffffa009d9ea>] ? i915_gem_retire_requests+0x9d/0xeb [i915]
[ 1572.550664]  [<ffffffffa009dd8c>] ? i915_gem_retire_work_handler+0x4c/0x61 [i915]
[ 1572.555825]  [<ffffffff8104ca7f>] ? process_one_work+0x1b2/0x31d
[ 1572.560951]  [<ffffffff8104d278>] ? worker_thread+0x24d/0x339
[ 1572.566033]  [<ffffffff8104d02b>] ? cancel_delayed_work_sync+0xa/0xa
[ 1572.571140]  [<ffffffff81050b25>] ? kthread+0xce/0xd6
[ 1572.576191]  [<ffffffff81050a57>] ? kthread_create_on_node+0x162/0x162
[ 1572.581228]  [<ffffffff8179b3c8>] ? ret_from_fork+0x58/0x90
[ 1572.586259]  [<ffffffff81050a57>] ? kthread_create_on_node+0x162/0x162
[ 1572.591318] Code: de 48 89 e7 e8 09 4d 00 e1 48 85 c0 74 27 48 89 68 10 48 8b 55 38 48 89 e7 48 89 50 18 48 8b 55 10 48 8b 12 48 8b 12 48 8b 52 38 <8b> 12 89 50 08 e8 95 4d 00 e1 48 83 c4 30 5b 5d 41 5c c3 41 55
[ 1572.596981] RIP  [<ffffffffa00b2514>] ftrace_raw_event_i915_context+0x5d/0x70 [i915]
[ 1572.602464]  RSP <ffff880035727ce8>
[ 1572.607911] CR2: 0000000000000000

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90112#c23
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/i915/i915_drv.h         | 1 +
 drivers/gpu/drm/i915/i915_gem_context.c | 4 ++--
 drivers/gpu/drm/i915/i915_trace.h       | 2 +-
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 542fac628b288..580762001f31d 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -826,6 +826,7 @@ struct intel_context {
 	struct kref ref;
 	int user_handle;
 	uint8_t remap_slice;
+	struct drm_i915_private *i915;
 	struct drm_i915_file_private *file_priv;
 	struct i915_ctx_hang_stats hang_stats;
 	struct i915_hw_ppgtt *ppgtt;
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index d65cbe6afb92d..48afa777e94aa 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -135,8 +135,7 @@ static int get_context_size(struct drm_device *dev)
 
 void i915_gem_context_free(struct kref *ctx_ref)
 {
-	struct intel_context *ctx = container_of(ctx_ref,
-						 typeof(*ctx), ref);
+	struct intel_context *ctx = container_of(ctx_ref, typeof(*ctx), ref);
 
 	trace_i915_context_free(ctx);
 
@@ -195,6 +194,7 @@ __create_hw_context(struct drm_device *dev,
 
 	kref_init(&ctx->ref);
 	list_add_tail(&ctx->link, &dev_priv->context_list);
+	ctx->i915 = dev_priv;
 
 	if (dev_priv->hw_context_size) {
 		struct drm_i915_gem_object *obj =
diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h
index 497cba5deb1e9..849a2590e010c 100644
--- a/drivers/gpu/drm/i915/i915_trace.h
+++ b/drivers/gpu/drm/i915/i915_trace.h
@@ -727,7 +727,7 @@ DECLARE_EVENT_CLASS(i915_context,
 	TP_fast_assign(
 			__entry->ctx = ctx;
 			__entry->vm = ctx->ppgtt ? &ctx->ppgtt->base : NULL;
-			__entry->dev = ctx->file_priv->dev_priv->dev->primary->index;
+			__entry->dev = ctx->i915->dev->primary->index;
 	),
 
 	TP_printk("dev=%u, ctx=%p, ctx_vm=%p",

From 94f7bbe1509731bdef651d7fb235b2c31fb23be8 Mon Sep 17 00:00:00 2001
From: Tomas Elf <tomas.elf@intel.com>
Date: Thu, 9 Jul 2015 15:30:57 +0100
Subject: [PATCH 2/9] drm/i915: Snapshot seqno of most recently submitted
 request.

The hang checker needs to inspect whether or not the ring request list is empty
as well as if the given engine has reached or passed the most recently
submitted request. The problem with this is that the hang checker cannot grab
the struct_mutex, which is required in order to safely inspect requests since
requests might be deallocated during inspection. In the past we've had kernel
panics due to this very unsynchronized access in the hang checker.

One solution to this problem is to not inspect the requests directly since
we're only interested in the seqno of the most recently submitted request - not
the request itself. Instead the seqno of the most recently submitted request is
stored separately, which the hang checker then inspects, circumventing the
issue of synchronization from the hang checker entirely.

This fixes a regression introduced in

commit 44cdd6d219bc64f6810b8ed0023a4d4db9e0fe68
Author: John Harrison <John.C.Harrison@Intel.com>
Date:   Mon Nov 24 18:49:40 2014 +0000

    drm/i915: Convert 'ring_idle()' to use requests not seqnos

v2 (Chris Wilson):
- Pass current engine seqno to ring_idle() from i915_hangcheck_elapsed() rather
than compute it over again.
- Remove extra whitespace.

Issue: VIZ-5998
Signed-off-by: Tomas Elf <tomas.elf@intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Add regressing commit citation provided by Chris.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/i915/i915_gem.c         |  1 +
 drivers/gpu/drm/i915/i915_irq.c         | 13 +++----------
 drivers/gpu/drm/i915/intel_ringbuffer.h |  7 +++++++
 3 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 248fd1ac7b3a0..716e5acc3bb0b 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2542,6 +2542,7 @@ int __i915_add_request(struct intel_engine_cs *ring,
 	}
 
 	request->emitted_jiffies = jiffies;
+	ring->last_submitted_seqno = request->seqno;
 	list_add_tail(&request->list, &ring->request_list);
 	request->file_priv = NULL;
 
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index e6bb72dca3ffb..984e2fe6688c4 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -2706,18 +2706,11 @@ static void gen8_disable_vblank(struct drm_device *dev, int pipe)
 	spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
 }
 
-static struct drm_i915_gem_request *
-ring_last_request(struct intel_engine_cs *ring)
-{
-	return list_entry(ring->request_list.prev,
-			  struct drm_i915_gem_request, list);
-}
-
 static bool
-ring_idle(struct intel_engine_cs *ring)
+ring_idle(struct intel_engine_cs *ring, u32 seqno)
 {
 	return (list_empty(&ring->request_list) ||
-		i915_gem_request_completed(ring_last_request(ring), false));
+		i915_seqno_passed(seqno, ring->last_submitted_seqno));
 }
 
 static bool
@@ -2939,7 +2932,7 @@ static void i915_hangcheck_elapsed(struct work_struct *work)
 		acthd = intel_ring_get_active_head(ring);
 
 		if (ring->hangcheck.seqno == seqno) {
-			if (ring_idle(ring)) {
+			if (ring_idle(ring, seqno)) {
 				ring->hangcheck.action = HANGCHECK_IDLE;
 
 				if (waitqueue_active(&ring->irq_queue)) {
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index e539314ae87e0..4be66f60504d1 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -275,6 +275,13 @@ struct  intel_engine_cs {
 	 * Do we have some not yet emitted requests outstanding?
 	 */
 	struct drm_i915_gem_request *outstanding_lazy_request;
+	/**
+	 * Seqno of request most recently submitted to request_list.
+	 * Used exclusively by hang checker to avoid grabbing lock while
+	 * inspecting request list.
+	 */
+	u32 last_submitted_seqno;
+
 	bool gpu_caches_dirty;
 
 	wait_queue_head_t irq_queue;

From e227330223a7721b4284c3921651bd9ca8f3581a Mon Sep 17 00:00:00 2001
From: Imre Deak <imre.deak@intel.com>
Date: Thu, 9 Jul 2015 12:59:05 +0300
Subject: [PATCH 3/9] drm/i915: avoid leaking DMA mappings

We have 3 types of DMA mappings for GEM objects:
1. physically contiguous for stolen and for objects needing contiguous
   memory
2. DMA-buf mappings imported via a DMA-buf attach operation
3. SG DMA mappings for shmem backed and userptr objects

For 1. and 2. the lifetime of the DMA mapping matches the lifetime of the
corresponding backing pages and so in practice we create/release the
mapping in the object's get_pages/put_pages callback.

For 3. the lifetime of the mapping matches that of any existing GPU binding
of the object, so we'll create the mapping when the object is bound to
the first vma and release the mapping when the object is unbound from its
last vma.

Since the object can be bound to multiple vmas, we can end up creating a
new DMA mapping in the 3. case even if the object already had one. This
is not allowed by the DMA API and can lead to leaked mapping data and
IOMMU memory space starvation in certain cases. For example HW IOMMU
drivers (intel_iommu) allocate a new range from their memory space
whenever a mapping is created, silently overriding a pre-existing
mapping.

Fix this by moving the creation/removal of DMA mappings to the object's
get_pages/put_pages callbacks. These callbacks already check for and do
an early return in case of any nested calls. This way objects of the 3.
case also become more like the other object types.

I noticed this issue by enabling DMA debugging, which got disabled after
a while due to its internal mapping tables getting full. It also reported
errors in connection to random other drivers that did a DMA mapping for
an address that was previously mapped by i915 but was never released.
Besides these diagnostic messages and the memory space starvation
problem for IOMMUs, I'm not aware of this causing a real issue.

The fix is based on a patch from Chris.

v2:
- move the DMA mapping create/remove calls to the get_pages/put_pages
  callbacks instead of adding new callbacks for these (Chris)
v3:
- also fix the get_page cache logic on the userptr async path (Chris)

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/i915/i915_gem.c         | 31 +++++++++++++------------
 drivers/gpu/drm/i915/i915_gem_userptr.c | 29 +++++++++++++++++++++--
 2 files changed, 43 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 716e5acc3bb0b..95b92ad1f2b5e 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2139,6 +2139,8 @@ i915_gem_object_put_pages_gtt(struct drm_i915_gem_object *obj)
 		obj->base.read_domains = obj->base.write_domain = I915_GEM_DOMAIN_CPU;
 	}
 
+	i915_gem_gtt_finish_object(obj);
+
 	if (i915_gem_object_needs_bit17_swizzle(obj))
 		i915_gem_object_save_bit_17_swizzle(obj);
 
@@ -2199,6 +2201,7 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
 	struct sg_page_iter sg_iter;
 	struct page *page;
 	unsigned long last_pfn = 0;	/* suppress gcc warning */
+	int ret;
 	gfp_t gfp;
 
 	/* Assert that the object is not currently in any GPU domain. As it
@@ -2246,8 +2249,10 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
 			 */
 			i915_gem_shrink_all(dev_priv);
 			page = shmem_read_mapping_page(mapping, i);
-			if (IS_ERR(page))
+			if (IS_ERR(page)) {
+				ret = PTR_ERR(page);
 				goto err_pages;
+			}
 		}
 #ifdef CONFIG_SWIOTLB
 		if (swiotlb_nr_tbl()) {
@@ -2276,6 +2281,10 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
 		sg_mark_end(sg);
 	obj->pages = st;
 
+	ret = i915_gem_gtt_prepare_object(obj);
+	if (ret)
+		goto err_pages;
+
 	if (i915_gem_object_needs_bit17_swizzle(obj))
 		i915_gem_object_do_bit_17_swizzle(obj);
 
@@ -2300,10 +2309,10 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
 	 * space and so want to translate the error from shmemfs back to our
 	 * usual understanding of ENOMEM.
 	 */
-	if (PTR_ERR(page) == -ENOSPC)
-		return -ENOMEM;
-	else
-		return PTR_ERR(page);
+	if (ret == -ENOSPC)
+		ret = -ENOMEM;
+
+	return ret;
 }
 
 /* Ensure that the associated pages are gathered from the backing storage
@@ -3248,10 +3257,8 @@ int i915_vma_unbind(struct i915_vma *vma)
 
 	/* Since the unbound list is global, only move to that list if
 	 * no more VMAs exist. */
-	if (list_empty(&obj->vma_list)) {
-		i915_gem_gtt_finish_object(obj);
+	if (list_empty(&obj->vma_list))
 		list_move_tail(&obj->global_list, &dev_priv->mm.unbound_list);
-	}
 
 	/* And finally now the object is completely decoupled from this vma,
 	 * we can drop its hold on the backing storage and allow it to be
@@ -3769,22 +3776,16 @@ i915_gem_object_bind_to_vm(struct drm_i915_gem_object *obj,
 		goto err_remove_node;
 	}
 
-	ret = i915_gem_gtt_prepare_object(obj);
-	if (ret)
-		goto err_remove_node;
-
 	trace_i915_vma_bind(vma, flags);
 	ret = i915_vma_bind(vma, obj->cache_level, flags);
 	if (ret)
-		goto err_finish_gtt;
+		goto err_remove_node;
 
 	list_move_tail(&obj->global_list, &dev_priv->mm.bound_list);
 	list_add_tail(&vma->mm_list, &vm->inactive_list);
 
 	return vma;
 
-err_finish_gtt:
-	i915_gem_gtt_finish_object(obj);
 err_remove_node:
 	drm_mm_remove_node(&vma->node);
 err_free_vma:
diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c
index 1f4e5a32a16e5..8fd431bcdfd3a 100644
--- a/drivers/gpu/drm/i915/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
@@ -545,6 +545,26 @@ st_set_pages(struct sg_table **st, struct page **pvec, int num_pages)
 	return ret;
 }
 
+static int
+__i915_gem_userptr_set_pages(struct drm_i915_gem_object *obj,
+			     struct page **pvec, int num_pages)
+{
+	int ret;
+
+	ret = st_set_pages(&obj->pages, pvec, num_pages);
+	if (ret)
+		return ret;
+
+	ret = i915_gem_gtt_prepare_object(obj);
+	if (ret) {
+		sg_free_table(obj->pages);
+		kfree(obj->pages);
+		obj->pages = NULL;
+	}
+
+	return ret;
+}
+
 static void
 __i915_gem_userptr_get_pages_worker(struct work_struct *_work)
 {
@@ -584,9 +604,12 @@ __i915_gem_userptr_get_pages_worker(struct work_struct *_work)
 	if (obj->userptr.work != &work->work) {
 		ret = 0;
 	} else if (pinned == num_pages) {
-		ret = st_set_pages(&obj->pages, pvec, num_pages);
+		ret = __i915_gem_userptr_set_pages(obj, pvec, num_pages);
 		if (ret == 0) {
 			list_add_tail(&obj->global_list, &to_i915(dev)->mm.unbound_list);
+			obj->get_page.sg = obj->pages->sgl;
+			obj->get_page.last = 0;
+
 			pinned = 0;
 		}
 	}
@@ -693,7 +716,7 @@ i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj)
 			}
 		}
 	} else {
-		ret = st_set_pages(&obj->pages, pvec, num_pages);
+		ret = __i915_gem_userptr_set_pages(obj, pvec, num_pages);
 		if (ret == 0) {
 			obj->userptr.work = NULL;
 			pinned = 0;
@@ -715,6 +738,8 @@ i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj)
 	if (obj->madv != I915_MADV_WILLNEED)
 		obj->dirty = 0;
 
+	i915_gem_gtt_finish_object(obj);
+
 	for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0) {
 		struct page *page = sg_page_iter_page(&sg_iter);
 

From 101057fa40c17e8ecd0cdcf74664235de3b69c34 Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Mon, 13 Jul 2015 09:23:19 +0200
Subject: [PATCH 4/9] drm/i915: Fix missing return warning for !CONFIG_DEBUGFS
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This broken code was introduced in

commit aa7471d228eb6dfddd0d201ea9746d6a2020972a
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Wed Apr 1 11:15:21 2015 +0300

    drm/i915: add i915 specific connector debugfs file for DPCD

v2: Drop hunk that accidentally crept in.

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Bob Paauwe <bob.j.paauwe@intel.com>
Cc: François Valenduc <francoisvalenduc@gmail.com>
Reported-by: François Valenduc <francoisvalenduc@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 580762001f31d..3be83aff9cd6a 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3117,7 +3117,8 @@ void i915_debugfs_cleanup(struct drm_minor *minor);
 int i915_debugfs_connector_add(struct drm_connector *connector);
 void intel_display_crc_init(struct drm_device *dev);
 #else
-static inline int i915_debugfs_connector_add(struct drm_connector *connector) {}
+static inline int i915_debugfs_connector_add(struct drm_connector *connector)
+{ return 0; }
 static inline void intel_display_crc_init(struct drm_device *dev) {}
 #endif
 

From 5ec5b51639ec81031b655eaacf95d4f36b75e9b4 Mon Sep 17 00:00:00 2001
From: Imre Deak <imre.deak@intel.com>
Date: Wed, 8 Jul 2015 19:18:59 +0300
Subject: [PATCH 5/9] drm/i915: remove unused has_dma_mapping flag

After the previous patch this flag will check always clear, as it's
never set for shmem backed and userptr objects, so we can remove it.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Yeah this isn't really fixes but it's a nice cleanup to
clarify the code but not really worth the hassle of backmerging. So
just add to -fixes, we're still early in -rc.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/i915/i915_drv.h        | 2 --
 drivers/gpu/drm/i915/i915_gem.c        | 3 ---
 drivers/gpu/drm/i915/i915_gem_dmabuf.c | 2 --
 drivers/gpu/drm/i915/i915_gem_gtt.c    | 9 ++-------
 drivers/gpu/drm/i915/i915_gem_stolen.c | 1 -
 5 files changed, 2 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3be83aff9cd6a..5f27290201e07 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2037,8 +2037,6 @@ struct drm_i915_gem_object {
 	unsigned int cache_level:3;
 	unsigned int cache_dirty:1;
 
-	unsigned int has_dma_mapping:1;
-
 	unsigned int frontbuffer_bits:INTEL_FRONTBUFFER_BITS;
 
 	unsigned int pin_display;
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 95b92ad1f2b5e..52b446b27b4d0 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -213,7 +213,6 @@ i915_gem_object_get_pages_phys(struct drm_i915_gem_object *obj)
 	sg_dma_len(sg) = obj->base.size;
 
 	obj->pages = st;
-	obj->has_dma_mapping = true;
 	return 0;
 }
 
@@ -265,8 +264,6 @@ i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj)
 
 	sg_free_table(obj->pages);
 	kfree(obj->pages);
-
-	obj->has_dma_mapping = false;
 }
 
 static void
diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
index 7998da27c5007..e9c2bfd85b526 100644
--- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
@@ -256,7 +256,6 @@ static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
 		return PTR_ERR(sg);
 
 	obj->pages = sg;
-	obj->has_dma_mapping = true;
 	return 0;
 }
 
@@ -264,7 +263,6 @@ static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj)
 {
 	dma_buf_unmap_attachment(obj->base.import_attach,
 				 obj->pages, DMA_BIDIRECTIONAL);
-	obj->has_dma_mapping = false;
 }
 
 static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index dcc6a88c560eb..56b52a4767d48 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -1723,9 +1723,6 @@ void i915_gem_suspend_gtt_mappings(struct drm_device *dev)
 
 int i915_gem_gtt_prepare_object(struct drm_i915_gem_object *obj)
 {
-	if (obj->has_dma_mapping)
-		return 0;
-
 	if (!dma_map_sg(&obj->base.dev->pdev->dev,
 			obj->pages->sgl, obj->pages->nents,
 			PCI_DMA_BIDIRECTIONAL))
@@ -1972,10 +1969,8 @@ void i915_gem_gtt_finish_object(struct drm_i915_gem_object *obj)
 
 	interruptible = do_idling(dev_priv);
 
-	if (!obj->has_dma_mapping)
-		dma_unmap_sg(&dev->pdev->dev,
-			     obj->pages->sgl, obj->pages->nents,
-			     PCI_DMA_BIDIRECTIONAL);
+	dma_unmap_sg(&dev->pdev->dev, obj->pages->sgl, obj->pages->nents,
+		     PCI_DMA_BIDIRECTIONAL);
 
 	undo_idling(dev_priv, interruptible);
 }
diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index 348ed5abcdbf6..8b5b784c62fea 100644
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -416,7 +416,6 @@ _i915_gem_object_create_stolen(struct drm_device *dev,
 	if (obj->pages == NULL)
 		goto cleanup;
 
-	obj->has_dma_mapping = true;
 	i915_gem_object_pin_pages(obj);
 	obj->stolen = stolen;
 

From bbf470202d697b7d57cc3febad578ec77fd7bded Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel@ffwll.ch>
Date: Mon, 13 Jul 2015 08:22:22 +0200
Subject: [PATCH 6/9] drm/i915: fix oops in primary_check_plane
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

On Sun, Jul 12, 2015 at 09:52:51AM -0700, Linus Torvalds wrote:
> On Sun, Jul 12, 2015 at 1:03 AM, Jörg Otte <jrg.otte@gmail.com> wrote:
> > BUG: unable to handle kernel NULL pointer dereference at 0000000000000009
> > IP: [<ffffffffbd3447bb>] 0xffffffffbd3447bb
>
> Ugh. Please enable KALLSYMS to get sane symbols.
>
> But yes, "crtc_state->base.active" is at offset 9 from "crtc_state",
> so it's pretty clearly just that change frm
>
> -       if (intel_crtc->active) {
> +       if (crtc_state->base.active) {
>
> and "crtc_state" is NULL.
>
> And the code very much knows that crtc_state can be NULL, since it's
> initialized with
>
>         crtc_state = state->base.state ?
>                 intel_atomic_get_crtc_state(state->base.state,
> intel_crtc) : NULL;
>
> Tssk. Daniel? Should I just revert that commit dec4f799d0a4
> ("drm/i915: Use crtc_state->active in primary check_plane func") for
> now, or is there a better fix? Like just checking crtc_state for NULL?

Indeed embarrassing. I've missed that we still have 1 caller left that's
using the transitional helpers, and those don't fill out
plane_state->state backpointers to the global atomic update since there is
no global atomic update for transitional helpers. Below diff should fix
this - we need to preferentially check crts_state->active and if that's
not set intel_crtc->active should yield the right result for the one
remaining caller (it's in the crtc_disable paths).

This fixes a regression introduced in

commit dec4f799d0a4c9edae20512fa60b0a36f3299ca2
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Tue Jul 7 11:15:47 2015 +0200

    drm/i915: Use crtc_state->active in primary check_plane func

which was quickly reverted in

commit 01e2d0627a9a6edb24c37db45db5ecb31e9de808
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sun Jul 12 15:00:20 2015 -0700

    Revert "drm/i915: Use crtc_state->active in primary check_plane func"

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jörg Otte <jrg.otte@gmail.com>
Reported-and-tested-by: Jörg Otte <jrg.otte@gmail.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 647b1404c4413..85ac6d85dc395 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -13276,7 +13276,7 @@ intel_check_primary_plane(struct drm_plane *plane,
 	if (ret)
 		return ret;
 
-	if (intel_crtc->active) {
+	if (crtc_state ? crtc_state->base.active : intel_crtc->active) {
 		struct intel_plane_state *old_state =
 			to_intel_plane_state(plane->state);
 

From ac7e7ab1c3243b10b41653cc8d8536088d83b152 Mon Sep 17 00:00:00 2001
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Date: Mon, 13 Jul 2015 16:51:39 +0100
Subject: [PATCH 7/9] drm/i915: Forward all core DRM ioctls to core compat
 handling

Previously only core DRM ioctls under the DRM_COMMAND_BASE were being
forwarded, but the drm.h header suggests (and reality confirms) ones
after (and including) DRM_COMMAND_END should be forwarded as well.

We need this to correctly forward the compat ioctl for the botched-up
addfb2.1 extension.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: stable@vger.kernel.org # 4.1+
[danvet: Explain why this is suddenly needed and add cc: stable.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/i915/i915_ioc32.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_ioc32.c b/drivers/gpu/drm/i915/i915_ioc32.c
index 176de6322e4d0..23aa04cded6b0 100644
--- a/drivers/gpu/drm/i915/i915_ioc32.c
+++ b/drivers/gpu/drm/i915/i915_ioc32.c
@@ -204,7 +204,7 @@ long i915_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 	drm_ioctl_compat_t *fn = NULL;
 	int ret;
 
-	if (nr < DRM_COMMAND_BASE)
+	if (nr < DRM_COMMAND_BASE || nr >= DRM_COMMAND_END)
 		return drm_compat_ioctl(filp, cmd, arg);
 
 	if (nr < DRM_COMMAND_BASE + ARRAY_SIZE(i915_compat_ioctls))

From d82c0ba6e306f079407f07003e53c262d683397b Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Tue, 14 Jul 2015 12:29:27 +0200
Subject: [PATCH 8/9] Revert "drm/i915: Declare the swizzling unknown for
 L-shaped configurations"

This reverts commit 19ee835cdb0b5a8eb11a68f25a51b8039d564488.

It breaks existing old userspace which doesn't handle UNKNOWN
swizzling correct. Yes UNKNOWN was a thing back in 2009 and probably
still is on some other platforms, but it still pretty clearly broke
the testers machine. If we want this we need to extend the ioctl with
new paramters that only new userspace looks at.

Cc: Harald Arnesen <harald@skogtun.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reported-by: Harald Arnesen <harald@skogtun.org>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
---
 drivers/gpu/drm/i915/i915_gem_tiling.c | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c
index d61e74a08f829..633bd1fcab692 100644
--- a/drivers/gpu/drm/i915/i915_gem_tiling.c
+++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
@@ -183,18 +183,8 @@ i915_gem_detect_bit_6_swizzle(struct drm_device *dev)
 		if (IS_GEN4(dev)) {
 			uint32_t ddc2 = I915_READ(DCC2);
 
-			if (!(ddc2 & DCC2_MODIFIED_ENHANCED_DISABLE)) {
-				/* Since the swizzling may vary within an
-				 * object, we have no idea what the swizzling
-				 * is for any page in particular. Thus we
-				 * cannot migrate tiled pages using the GPU,
-				 * nor can we tell userspace what the exact
-				 * swizzling is for any object.
-				 */
+			if (!(ddc2 & DCC2_MODIFIED_ENHANCED_DISABLE))
 				dev_priv->quirks |= QUIRK_PIN_SWIZZLED_PAGES;
-				swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN;
-				swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN;
-			}
 		}
 
 		if (dcc == 0xffffffff) {

From ccfb8b2ed4d4e12c3c35de3db5fbbbaa11277736 Mon Sep 17 00:00:00 2001
From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Date: Tue, 14 Jul 2015 13:00:39 +0200
Subject: [PATCH 9/9] drm/i915: Do not call intel_crtc_disable if the crtc is
 already disabled.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

When resuming with dpms off, the following warn can happen:

[  118.334082] ------------[ cut here ]------------
[  118.334105] WARNING: CPU: 2 PID: 2274 at drivers/gpu/drm/i915/intel_display.c:6319 __intel_set_mode+0xae5/0xb90 [i915]()
[  118.334106] WARN_ON(!crtc->state->enable)
[  118.334137] Modules linked in: i915
[  118.334139] CPU: 2 PID: 2274 Comm: kworker/u16:117 Not tainted 4.2.0-rc2-fixes+ #4148
[  118.334140] Hardware name: LENOVO 2349AV8/2349AV8, BIOS G1ETA5WW (2.65 ) 04/15/2014
[  118.334144] Workqueue: events_unbound async_run_entry_fn
[  118.334147]  ffffffffc017eef0 ffff8800ada93998 ffffffff817aa62a 0000000080000001
[  118.334149]  ffff8800ada939e8 ffff8800ada939d8 ffffffff810807e1 ffff8800ada939c8
[  118.334151]  ffff8800cea3b3d8 0000000000000000 ffff8800ad86b008 ffff880117705668
[  118.334151] Call Trace:
[  118.334155]  [<ffffffff817aa62a>] dump_stack+0x4f/0x7b
[  118.334157]  [<ffffffff810807e1>] warn_slowpath_common+0x81/0xc0
[  118.334158]  [<ffffffff81080861>] warn_slowpath_fmt+0x41/0x50
[  118.334173]  [<ffffffffc0120375>] __intel_set_mode+0xae5/0xb90 [i915]
[  118.334188]  [<ffffffffc0121312>] ? intel_modeset_compute_config+0x52/0xb40 [i915]
[  118.334191]  [<ffffffff8144de53>] ? drm_atomic_set_fb_for_plane+0x63/0x80
[  118.334205]  [<ffffffffc01269d9>] intel_set_mode+0x29/0x60 [i915]
[  118.334219]  [<ffffffffc012730a>] intel_crtc_restore_mode+0x13a/0x1f0 [i915]
[  118.334232]  [<ffffffffc0101160>] ? gen6_write16+0x250/0x250 [i915]
[  118.334246]  [<ffffffffc01283ec>] intel_modeset_setup_hw_state+0x89c/0xcd0 [i915]
[  118.334248]  [<ffffffff8137d260>] ? pci_pm_thaw+0x90/0x90
[  118.334255]  [<ffffffffc00ac11b>] i915_drm_resume+0xcb/0x160 [i915]
[  118.334262]  [<ffffffffc00ac1d2>] i915_pm_resume+0x22/0x30 [i915]
[  118.334263]  [<ffffffff8137d2c3>] pci_pm_resume+0x63/0xa0
[  118.334266]  [<ffffffff81467550>] dpm_run_callback+0x70/0x420
[  118.334267]  [<ffffffff81467cbd>] device_resume+0x9d/0x1c0
[  118.334269]  [<ffffffff814673d0>] ? initcall_debug_start+0x60/0x60
[  118.334270]  [<ffffffff81467dfc>] async_resume+0x1c/0x50
[  118.334271]  [<ffffffff810a6a94>] async_run_entry_fn+0x34/0xd0
[  118.334273]  [<ffffffff8109d4ad>] process_one_work+0x1dd/0x7e0
[  118.334275]  [<ffffffff8109d41a>] ? process_one_work+0x14a/0x7e0
[  118.334276]  [<ffffffff8109daf9>] worker_thread+0x49/0x450
[  118.334278]  [<ffffffff8109dab0>] ? process_one_work+0x7e0/0x7e0
[  118.334280]  [<ffffffff810a3cb9>] kthread+0xf9/0x110
[  118.334282]  [<ffffffff810a3bc0>] ? insert_kthread_work+0x90/0x90
[  118.334284]  [<ffffffff817b414f>] ret_from_fork+0x3f/0x70
[  118.334286]  [<ffffffff810a3bc0>] ? insert_kthread_work+0x90/0x90
[  118.334287] ---[ end trace 01f2cf6371b82d7a ]---

This warn is harmless, and can be fixed by not calling intel_crtc_disable when
the crtc is already disabled.

Reported-and-Tested-by: Jörg Otte <jrg.otte@gmail.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/i915/intel_display.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 85ac6d85dc395..30e0f54ba19d1 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6315,9 +6315,6 @@ static void intel_crtc_disable(struct drm_crtc *crtc)
 	struct drm_connector *connector;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
-	/* crtc should still be enabled when we disable it. */
-	WARN_ON(!crtc->state->enable);
-
 	intel_crtc_disable_planes(crtc);
 	dev_priv->display.crtc_disable(crtc);
 	dev_priv->display.off(crtc);
@@ -12591,7 +12588,8 @@ static int __intel_set_mode(struct drm_crtc *modeset_crtc,
 			continue;
 
 		if (!crtc_state->enable) {
-			intel_crtc_disable(crtc);
+			if (crtc->state->enable)
+				intel_crtc_disable(crtc);
 		} else if (crtc->state->enable) {
 			intel_crtc_disable_planes(crtc);
 			dev_priv->display.crtc_disable(crtc);