Linux-Wireless Archive on lore.kernel.org
 help / color / Atom feed
From: Christoph Hellwig <hch@lst.de>
To: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <maxime.ripard@bootlin.com>,
	Sean Paul <sean@poorly.run>, David Airlie <airlied@linux.ie>,
	Daniel Vetter <daniel@ffwll.ch>,
	Jani Nikula <jani.nikula@linux.intel.com>,
	Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
	Rodrigo Vivi <rodrigo.vivi@intel.com>,
	Ian Abbott <abbotti@mev.co.uk>,
	H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Intel Linux Wireless <linuxwifi@intel.com>,
	linux-arm-kernel@lists.infradead.org (moderated list:ARM PORT),
	dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org,
	linux-rdma@vger.kernel.org, linux-media@vger.kernel.org,
	netdev@vger.kernel.org, linux-wireless@vger.kernel.org,
	linux-s390@vger.kernel.org, devel@driverdev.osuosl.org,
	linux-mm@kvack.org, iommu@lists.linux-foundation.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 15/16] dma-mapping: clear __GFP_COMP in dma_alloc_attrs
Date: Fri, 14 Jun 2019 15:47:25 +0200
Message-ID: <20190614134726.3827-16-hch@lst.de> (raw)
In-Reply-To: <20190614134726.3827-1-hch@lst.de>

Lift the code to clear __GFP_COMP from arm into the common DMA
allocator path.  For one this fixes the various other patches that
call alloc_pages_exact or split_page in case a bogus driver passes
the argument, and it also prepares for doing exact allocation in
the generic dma-direct allocator.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/arm/mm/dma-mapping.c | 17 -----------------
 kernel/dma/mapping.c      |  9 +++++++++
 2 files changed, 9 insertions(+), 17 deletions(-)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 0a75058c11f3..86135feb2c05 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -759,14 +759,6 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
 	if (mask < 0xffffffffULL)
 		gfp |= GFP_DMA;
 
-	/*
-	 * Following is a work-around (a.k.a. hack) to prevent pages
-	 * with __GFP_COMP being passed to split_page() which cannot
-	 * handle them.  The real problem is that this flag probably
-	 * should be 0 on ARM as it is not supported on this
-	 * platform; see CONFIG_HUGETLBFS.
-	 */
-	gfp &= ~(__GFP_COMP);
 	args.gfp = gfp;
 
 	*handle = DMA_MAPPING_ERROR;
@@ -1527,15 +1519,6 @@ static void *__arm_iommu_alloc_attrs(struct device *dev, size_t size,
 		return __iommu_alloc_simple(dev, size, gfp, handle,
 					    coherent_flag, attrs);
 
-	/*
-	 * Following is a work-around (a.k.a. hack) to prevent pages
-	 * with __GFP_COMP being passed to split_page() which cannot
-	 * handle them.  The real problem is that this flag probably
-	 * should be 0 on ARM as it is not supported on this
-	 * platform; see CONFIG_HUGETLBFS.
-	 */
-	gfp &= ~(__GFP_COMP);
-
 	pages = __iommu_alloc_buffer(dev, size, gfp, attrs, coherent_flag);
 	if (!pages)
 		return NULL;
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index f7afdadb6770..4b618e1abbc1 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -252,6 +252,15 @@ void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
 	/* let the implementation decide on the zone to allocate from: */
 	flag &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
 
+	/*
+	 * __GFP_COMP interacts badly with splitting up a larger order
+	 * allocation.  But as our allocations might not even come from the
+	 * page allocator, the callers can't rely on the fact that they
+	 * even get pages, never mind which kind.
+	 */
+	if (WARN_ON_ONCE(flag & __GFP_COMP))
+		flag &= ~__GFP_COMP;
+
 	if (dma_is_direct(ops))
 		cpu_addr = dma_direct_alloc(dev, size, dma_handle, flag, attrs);
 	else if (ops->alloc)
-- 
2.20.1


  parent reply index

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-14 13:47 use exact allocation for dma coherent memory Christoph Hellwig
2019-06-14 13:47 ` [PATCH 01/16] media: videobuf-dma-contig: use dma_mmap_coherent Christoph Hellwig
2019-06-14 13:47 ` [PATCH 02/16] drm/ati_pcigart: stop using drm_pci_alloc Christoph Hellwig
2019-06-14 13:47 ` [PATCH 03/16] drm/i915: " Christoph Hellwig
2019-06-14 16:45   ` [Intel-gfx] " Ville Syrjälä
2019-06-14 13:47 ` [PATCH 04/16] drm: move drm_pci_{alloc,free} to drm_legacy Christoph Hellwig
2019-06-14 13:47 ` [PATCH 05/16] drm: don't mark pages returned from drm_pci_alloc reserved Christoph Hellwig
2019-06-14 13:47 ` [PATCH 06/16] drm: don't pass __GFP_COMP to dma_alloc_coherent in drm_pci_alloc Christoph Hellwig
2019-06-14 13:47 ` [PATCH 07/16] IB/hfi1: stop passing bogus gfp flags arguments to dma_alloc_coherent Christoph Hellwig
2019-06-14 13:47 ` [PATCH 08/16] IB/qib: " Christoph Hellwig
2019-06-14 13:47 ` [PATCH 09/16] cnic: " Christoph Hellwig
2019-06-14 13:47 ` [PATCH 10/16] iwlwifi: " Christoph Hellwig
2019-06-14 13:47 ` [PATCH 11/16] s390/ism: " Christoph Hellwig
2019-06-14 13:47 ` [PATCH 12/16] staging/comedi: mark as broken Christoph Hellwig
2019-06-14 14:02   ` Greg KH
2019-06-14 14:48     ` Christoph Hellwig
2019-06-14 15:30       ` Greg KH
2019-06-14 15:34         ` Christoph Hellwig
2019-06-17 13:15           ` Ian Abbott
2019-06-14 13:47 ` [PATCH 13/16] mm: rename alloc_pages_exact_nid to alloc_pages_exact_node Christoph Hellwig
2019-06-14 13:47 ` [PATCH 14/16] mm: use alloc_pages_exact_node to implement alloc_pages_exact Christoph Hellwig
2019-06-14 13:47 ` Christoph Hellwig [this message]
2019-06-14 13:47 ` [PATCH 16/16] dma-mapping: use exact allocation in dma_alloc_contiguous Christoph Hellwig
2019-06-14 14:15   ` David Laight
2019-06-14 14:50     ` Christoph Hellwig
2019-06-14 15:01       ` David Laight
2019-06-14 15:05         ` Christoph Hellwig
2019-06-14 15:05       ` Robin Murphy
2019-06-14 15:08         ` Christoph Hellwig
2019-06-14 15:16         ` David Laight
2019-06-17  8:21 ` use exact allocation for dma coherent memory Dan Carpenter
2019-06-17  8:33   ` Christoph Hellwig
2019-06-19 16:29     ` Jason Gunthorpe
2019-06-20 10:51       ` Christoph Hellwig
2019-07-01  8:48 ` Christoph Hellwig
2019-07-02  9:48   ` Arend Van Spriel
2019-07-08 18:43     ` Christoph Hellwig

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190614134726.3827-16-hch@lst.de \
    --to=hch@lst.de \
    --cc=abbotti@mev.co.uk \
    --cc=airlied@linux.ie \
    --cc=daniel@ffwll.ch \
    --cc=hsweeten@visionengravers.com \
    --cc=jani.nikula@linux.intel.com \
    --cc=joonas.lahtinen@linux.intel.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linuxwifi@intel.com \
    --cc=maarten.lankhorst@linux.intel.com \
    --cc=maxime.ripard@bootlin.com \
    --cc=rodrigo.vivi@intel.com \
    --cc=sean@poorly.run \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Wireless Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-wireless/0 linux-wireless/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-wireless linux-wireless/ https://lore.kernel.org/linux-wireless \
		linux-wireless@vger.kernel.org linux-wireless@archiver.kernel.org
	public-inbox-index linux-wireless


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-wireless


AGPL code for this site: git clone https://public-inbox.org/ public-inbox