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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /include/drm/drm_cache.h
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'include/drm/drm_cache.h')
-rw-r--r--include/drm/drm_cache.h73
1 files changed, 73 insertions, 0 deletions
diff --git a/include/drm/drm_cache.h b/include/drm/drm_cache.h
new file mode 100644
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+++ b/include/drm/drm_cache.h
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+/**************************************************************************
+ *
+ * Copyright 2009 Red Hat Inc.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ *
+ **************************************************************************/
+/*
+ * Authors:
+ * Dave Airlie <airlied@redhat.com>
+ */
+
+#ifndef _DRM_CACHE_H_
+#define _DRM_CACHE_H_
+
+#include <linux/scatterlist.h>
+
+void drm_clflush_pages(struct page *pages[], unsigned long num_pages);
+void drm_clflush_sg(struct sg_table *st);
+void drm_clflush_virt_range(void *addr, unsigned long length);
+u64 drm_get_max_iomem(void);
+
+
+static inline bool drm_arch_can_wc_memory(void)
+{
+#if defined(CONFIG_PPC) && !defined(CONFIG_NOT_COHERENT_CACHE)
+ return false;
+#elif defined(CONFIG_MIPS) && defined(CONFIG_CPU_LOONGSON3)
+ return false;
+#elif defined(CONFIG_ARM) || defined(CONFIG_ARM64)
+ /*
+ * The DRM driver stack is designed to work with cache coherent devices
+ * only, but permits an optimization to be enabled in some cases, where
+ * for some buffers, both the CPU and the GPU use uncached mappings,
+ * removing the need for DMA snooping and allocation in the CPU caches.
+ *
+ * The use of uncached GPU mappings relies on the correct implementation
+ * of the PCIe NoSnoop TLP attribute by the platform, otherwise the GPU
+ * will use cached mappings nonetheless. On x86 platforms, this does not
+ * seem to matter, as uncached CPU mappings will snoop the caches in any
+ * case. However, on ARM and arm64, enabling this optimization on a
+ * platform where NoSnoop is ignored results in loss of coherency, which
+ * breaks correct operation of the device. Since we have no way of
+ * detecting whether NoSnoop works or not, just disable this
+ * optimization entirely for ARM and arm64.
+ */
+ return false;
+#else
+ return true;
+#endif
+}
+
+#endif