From: Ira Weiny <ira.weiny@intel.com>
To: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
Cc: David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
Patrik Jakobsson <patrik.r.jakobsson@gmail.com>,
Rob Clark <robdclark@gmail.com>, Sean Paul <sean@poorly.run>,
linux-arm-msm@vger.kernel.org, intel-gfx@lists.freedesktop.org,
linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
amd-gfx@lists.freedesktop.org
Subject: Re: [PATCH 1/7] drm/i915: Replace kmap() with kmap_local_page()
Date: Mon, 13 Dec 2021 07:45:43 -0800 [thread overview]
Message-ID: <20211213154543.GM3538886@iweiny-DESK2.sc.intel.com> (raw)
In-Reply-To: <Ybc/HwaG2vgbdkQr@intel.com>
On Mon, Dec 13, 2021 at 02:39:59PM +0200, Ville Syrjälä wrote:
> On Fri, Dec 10, 2021 at 03:23:58PM -0800, ira.weiny@intel.com wrote:
> > From: Ira Weiny <ira.weiny@intel.com>
> >
> > kmap() is being deprecated and these usages are all local to the thread
> > so there is no reason kmap_local_page() can't be used.
> >
> > Replace kmap() calls with kmap_local_page().
> >
> > Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> > ---
> > drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 4 ++--
> > drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c | 8 ++++----
> > drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c | 4 ++--
> > drivers/gpu/drm/i915/gt/shmem_utils.c | 4 ++--
> > drivers/gpu/drm/i915/i915_gem.c | 8 ++++----
> > drivers/gpu/drm/i915/i915_gpu_error.c | 4 ++--
> > 6 files changed, 16 insertions(+), 16 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> > index d77da59fae04..fa8b820e14aa 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> > @@ -597,9 +597,9 @@ i915_gem_object_create_shmem_from_data(struct drm_i915_private *dev_priv,
> > if (err < 0)
> > goto fail;
> >
> > - vaddr = kmap(page);
> > + vaddr = kmap_local_page(page);
> > memcpy(vaddr, data, len);
> > - kunmap(page);
> > + kunmap_local(vaddr);
> >
> > err = pagecache_write_end(file, file->f_mapping,
> > offset, len, len,
> > diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
> > index 6d30cdfa80f3..e59e1725e29d 100644
> > --- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
> > +++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
> > @@ -144,7 +144,7 @@ static int check_partial_mapping(struct drm_i915_gem_object *obj,
> > intel_gt_flush_ggtt_writes(&to_i915(obj->base.dev)->gt);
> >
> > p = i915_gem_object_get_page(obj, offset >> PAGE_SHIFT);
> > - cpu = kmap(p) + offset_in_page(offset);
> > + cpu = kmap_local_page(p) + offset_in_page(offset);
>
> Does kunmap_local() do some magic to make it work even when you
> don't pass in the same value you got from kmap_local_page()?
Yes. It sounds like a patch like this would be nice to clarify?
Ira
diff --git a/include/linux/highmem-internal.h b/include/linux/highmem-internal.h
index 0a0b2b09b1b8..fb2d3e033c01 100644
--- a/include/linux/highmem-internal.h
+++ b/include/linux/highmem-internal.h
@@ -246,6 +246,17 @@ do { \
__kunmap_atomic(__addr); \
} while (0)
+/**
+ * kunmap_local - Unmap a page mapped via kmap_local_page().
+ * @__addr: An address within the page mapped
+ *
+ * __addr is often an address returned from kmap_local_page(). However,
+ * this address can be any address within the mapped page. It does not need to
+ * be the exact address returned from kmap_local_page()
+ *
+ * Unmapping should be done in the reverse order of the mapping. See
+ * kmap_local_page() for details.
+ */
#define kunmap_local(__addr) \
do { \
BUILD_BUG_ON(__same_type((__addr), struct page *)); \
next prev parent reply other threads:[~2021-12-13 15:45 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-10 23:23 [PATCH 0/7] DRM kmap() fixes and kmap_local_page() conversions ira.weiny
2021-12-10 23:23 ` [PATCH 1/7] drm/i915: Replace kmap() with kmap_local_page() ira.weiny
2021-12-13 9:04 ` Christoph Hellwig
2021-12-13 16:02 ` Ira Weiny
2021-12-13 12:39 ` Ville Syrjälä
2021-12-13 15:45 ` Ira Weiny [this message]
2021-12-22 6:08 ` [PATCH V2] " ira.weiny
2021-12-10 23:23 ` [PATCH 2/7] drm/amd: " ira.weiny
2021-12-10 23:24 ` [PATCH 3/7] drm/gma: Remove calls to kmap() ira.weiny
2021-12-10 23:24 ` [PATCH 4/7] drm/radeon: Replace kmap() with kmap_local_page() ira.weiny
2021-12-10 23:24 ` [PATCH 5/7] drm/msm: Alter comment to use kmap_local_page() ira.weiny
2021-12-10 23:24 ` [PATCH 6/7] drm/amdgpu: Ensure kunmap is called on error ira.weiny
2021-12-13 20:37 ` Christian König
2021-12-14 3:37 ` Ira Weiny
2021-12-14 7:09 ` Christian König
2021-12-15 21:09 ` Ira Weiny
2021-12-16 8:32 ` Christian König
2021-12-10 23:24 ` [PATCH 7/7] drm/radeon: " ira.weiny
2022-01-19 16:53 ` [PATCH 0/7] DRM kmap() fixes and kmap_local_page() conversions Ira Weiny
2022-01-19 17:24 ` Daniel Vetter
2022-01-19 23:55 ` Ira Weiny
2022-01-20 8:16 ` Christian König
2022-01-20 15:48 ` [Intel-gfx] " Daniel Vetter
2022-01-20 16:57 ` Ira Weiny
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