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authorRob Herring <robh@kernel.org>2019-08-05 08:33:58 -0600
committerRob Herring <robh@kernel.org>2019-08-08 15:57:36 -0600
commit013b6510131568ce4e01856d5360bfdfe9c3632f (patch)
tree7c6b481c2a64a7dc2178c82622b0736bf0325084 /include
parent17acb9f35ed736c177f85b8ee711f278e7aff421 (diff)
drm/panfrost: Add madvise and shrinker support
Add support for madvise and a shrinker similar to other drivers. This allows userspace to mark BOs which can be freed when there is memory pressure. Unlike other implementations, we don't depend on struct_mutex. The driver maintains a list of BOs which can be freed when the shrinker is called. Access to the list is serialized with the shrinker_lock. Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Signed-off-by: Rob Herring <robh@kernel.org> Link: https://patchwork.freedesktop.org/patch/msgid/20190805143358.21245-2-robh@kernel.org
Diffstat (limited to 'include')
-rw-r--r--include/uapi/drm/panfrost_drm.h22
1 files changed, 22 insertions, 0 deletions
diff --git a/include/uapi/drm/panfrost_drm.h b/include/uapi/drm/panfrost_drm.h
index cb577fb96b38..1e547f9692e9 100644
--- a/include/uapi/drm/panfrost_drm.h
+++ b/include/uapi/drm/panfrost_drm.h
@@ -20,6 +20,7 @@ extern "C" {
#define DRM_PANFROST_GET_BO_OFFSET 0x05
#define DRM_PANFROST_PERFCNT_ENABLE 0x06
#define DRM_PANFROST_PERFCNT_DUMP 0x07
+#define DRM_PANFROST_MADVISE 0x08
#define DRM_IOCTL_PANFROST_SUBMIT DRM_IOW(DRM_COMMAND_BASE + DRM_PANFROST_SUBMIT, struct drm_panfrost_submit)
#define DRM_IOCTL_PANFROST_WAIT_BO DRM_IOW(DRM_COMMAND_BASE + DRM_PANFROST_WAIT_BO, struct drm_panfrost_wait_bo)
@@ -27,6 +28,7 @@ extern "C" {
#define DRM_IOCTL_PANFROST_MMAP_BO DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_MMAP_BO, struct drm_panfrost_mmap_bo)
#define DRM_IOCTL_PANFROST_GET_PARAM DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_GET_PARAM, struct drm_panfrost_get_param)
#define DRM_IOCTL_PANFROST_GET_BO_OFFSET DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_GET_BO_OFFSET, struct drm_panfrost_get_bo_offset)
+#define DRM_IOCTL_PANFROST_MADVISE DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_MADVISE, struct drm_panfrost_madvise)
/*
* Unstable ioctl(s): only exposed when the unsafe unstable_ioctls module
@@ -198,6 +200,26 @@ struct drm_panfrost_perfcnt_dump {
__u64 buf_ptr;
};
+/* madvise provides a way to tell the kernel in case a buffers contents
+ * can be discarded under memory pressure, which is useful for userspace
+ * bo cache where we want to optimistically hold on to buffer allocate
+ * and potential mmap, but allow the pages to be discarded under memory
+ * pressure.
+ *
+ * Typical usage would involve madvise(DONTNEED) when buffer enters BO
+ * cache, and madvise(WILLNEED) if trying to recycle buffer from BO cache.
+ * In the WILLNEED case, 'retained' indicates to userspace whether the
+ * backing pages still exist.
+ */
+#define PANFROST_MADV_WILLNEED 0 /* backing pages are needed, status returned in 'retained' */
+#define PANFROST_MADV_DONTNEED 1 /* backing pages not needed */
+
+struct drm_panfrost_madvise {
+ __u32 handle; /* in, GEM handle */
+ __u32 madv; /* in, PANFROST_MADV_x */
+ __u32 retained; /* out, whether backing store still exists */
+};
+
#if defined(__cplusplus)
}
#endif