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authorDaniel Vetter <daniel.vetter@ffwll.ch>2019-12-17 15:57:54 +0300
committerDaniel Vetter <daniel.vetter@ffwll.ch>2019-12-17 15:57:54 +0300
commit6c56e8adc0011b3bc01b6b2bab7e41d5ecb43c0f (patch)
tree3baa1c367f120d7fcc1c30dbb8a6aff5fa5dd672 /drivers/dma-buf/dma-buf.c
parentd1eef1c619749b2a57e514a3fa67d9a516ffa919 (diff)
parent2156873f08c7893811f34177aa923ab1ea486591 (diff)
downloadlinux-6c56e8adc0011b3bc01b6b2bab7e41d5ecb43c0f.tar.xz
Merge tag 'drm-misc-next-2019-12-16' of git://anongit.freedesktop.org/drm/drm-misc into drm-next
drm-misc-next for v5.6: UAPI Changes: - Add support for DMA-BUF HEAPS. Cross-subsystem Changes: - mipi dsi definition updates, pulled into drm-intel as well. - Add lockdep annotations for dma_resv vs mmap_sem and fs_reclaim. - Remove support for dma-buf kmap/kunmap. - Constify fb_ops in all fbdev drivers, including drm drivers and drm-core, and media as well. Core Changes: - Small cleanups to ttm. - Fix SCDC definition. - Assorted cleanups to core. - Add todo to remove load/unload hooks, and use generic fbdev emulation. - Assorted documentation updates. - Use blocking ww lock in ttm fault handler. - Remove drm_fb_helper_fbdev_setup/teardown. - Warning fixes with W=1 for atomic. - Use drm_debug_enabled() instead of drm_debug flag testing in various drivers. - Fallback to nontiled mode in fbdev emulation when not all tiles are present. (Later on reverted) - Various kconfig indentation fixes in core and drivers. - Fix freeing transactions in dp-mst correctly. - Sean Paul is steping down as core maintainer. :-( - Add lockdep annotations for atomic locks vs dma-resv. - Prevent use-after-free for a bad job in drm_scheduler. - Fill out all block sizes in the P01x and P210 definitions. - Avoid division by zero in drm/rect, and fix bounds. - Add drm/rect selftests. - Add aspect ratio and alternate clocks for HDMI 4k modes. - Add todo for drm_framebuffer_funcs and fb_create cleanup. - Drop DRM_AUTH for prime import/export ioctls. - Clear DP-MST payload id tables downstream when initializating. - Fix for DSC throughput definition. - Add extra FEC definitions. - Fix fake offset in drm_gem_object_funs.mmap. - Stop using encoder->bridge in core directly - Handle bridge chaining slightly better. - Add backlight support to drm/panel, and use it in many panel drivers. - Increase max number of y420 modes from 128 to 256, as preparation to add the new modes. Driver Changes: - Small fixes all over. - Fix documentation in vkms. - Fix mmap_sem vs dma_resv in nouveau. - Small cleanup in komeda. - Add page flip support in gma500 for psb/cdv. - Add ddc symlink in the connector sysfs directory for many drivers. - Add support for analogic an6345, and fix small bugs in it. - Add atomic modesetting support to ast. - Fix radeon fault handler VMA race. - Switch udl to use generic shmem helpers. - Unconditional vblank handling for mcde. - Miscellaneous fixes to mcde. - Tweak debug output from komeda using debugfs. - Add gamma and color transform support to komeda for DOU-IPS. - Add support for sony acx424AKP panel. - Various small cleanups to gma500. - Use generic fbdev emulation in udl, and replace udl_framebuffer with generic implementation. - Add support for Logic PD Type 28 panel. - Use drm_panel_* wrapper functions in exynos/tegra/msm. - Add devicetree bindings for generic DSI panels. - Don't include drm_pci.h directly in many drivers. - Add support for begin/end_cpu_access in udmabuf. - Stop using drm_get_pci_dev in gma500 and mga200. - Fixes to UDL damage handling, and use dma_buf_begin/end_cpu_access. - Add devfreq thermal support to panfrost. - Fix hotplug with daisy chained monitors by removing VCPI when disabling topology manager. - meson: Add support for OSD1 plane AFBC commit. - Stop displaying garbage when toggling ast primary plane on/off. - More cleanups and fixes to UDL. - Add D32 suport to komeda. - Remove globle copy of drm_dev in gma500. - Add support for Boe Himax8279d MIPI-DSI LCD panel. - Add support for ingenic JZ4770 panel. - Small null pointer deference fix in ingenic. - Remove support for the special tfp420 driver, as there is a generic way to do it. Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/ba73535a-9334-5302-2e1f-5208bd7390bd@linux.intel.com
Diffstat (limited to 'drivers/dma-buf/dma-buf.c')
-rw-r--r--drivers/dma-buf/dma-buf.c63
1 files changed, 3 insertions, 60 deletions
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index ce41cd9b758a..d4097856c86b 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -878,29 +878,9 @@ EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);
* with calls to dma_buf_begin_cpu_access() and dma_buf_end_cpu_access()
* access.
*
- * To support dma_buf objects residing in highmem cpu access is page-based
- * using an api similar to kmap. Accessing a dma_buf is done in aligned chunks
- * of PAGE_SIZE size. Before accessing a chunk it needs to be mapped, which
- * returns a pointer in kernel virtual address space. Afterwards the chunk
- * needs to be unmapped again. There is no limit on how often a given chunk
- * can be mapped and unmapped, i.e. the importer does not need to call
- * begin_cpu_access again before mapping the same chunk again.
- *
- * Interfaces::
- * void \*dma_buf_kmap(struct dma_buf \*, unsigned long);
- * void dma_buf_kunmap(struct dma_buf \*, unsigned long, void \*);
- *
- * Implementing the functions is optional for exporters and for importers all
- * the restrictions of using kmap apply.
- *
- * dma_buf kmap calls outside of the range specified in begin_cpu_access are
- * undefined. If the range is not PAGE_SIZE aligned, kmap needs to succeed on
- * the partial chunks at the beginning and end but may return stale or bogus
- * data outside of the range (in these partial chunks).
- *
- * For some cases the overhead of kmap can be too high, a vmap interface
- * is introduced. This interface should be used very carefully, as vmalloc
- * space is a limited resources on many architectures.
+ * Since for most kernel internal dma-buf accesses need the entire buffer, a
+ * vmap interface is introduced. Note that on very old 32-bit architectures
+ * vmalloc space might be limited and result in vmap calls failing.
*
* Interfaces::
* void \*dma_buf_vmap(struct dma_buf \*dmabuf)
@@ -1050,43 +1030,6 @@ int dma_buf_end_cpu_access(struct dma_buf *dmabuf,
}
EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access);
-/**
- * dma_buf_kmap - Map a page of the buffer object into kernel address space. The
- * same restrictions as for kmap and friends apply.
- * @dmabuf: [in] buffer to map page from.
- * @page_num: [in] page in PAGE_SIZE units to map.
- *
- * This call must always succeed, any necessary preparations that might fail
- * need to be done in begin_cpu_access.
- */
-void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num)
-{
- WARN_ON(!dmabuf);
-
- if (!dmabuf->ops->map)
- return NULL;
- return dmabuf->ops->map(dmabuf, page_num);
-}
-EXPORT_SYMBOL_GPL(dma_buf_kmap);
-
-/**
- * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap.
- * @dmabuf: [in] buffer to unmap page from.
- * @page_num: [in] page in PAGE_SIZE units to unmap.
- * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap.
- *
- * This call must always succeed.
- */
-void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num,
- void *vaddr)
-{
- WARN_ON(!dmabuf);
-
- if (dmabuf->ops->unmap)
- dmabuf->ops->unmap(dmabuf, page_num, vaddr);
-}
-EXPORT_SYMBOL_GPL(dma_buf_kunmap);
-
/**
* dma_buf_mmap - Setup up a userspace mmap with the given vma